JP2018147264A - Drive control device and drive device - Google Patents

Abstract

Provided is a manipulator capable of avoiding an increase in cost by providing a plurality of dedicated temperature sensors corresponding to each of a plurality of reduction gears. A motor 105, a speed reducer 106, a temperature of a lubricant in the speed reducer 106, a rotational speed of the motor 105, and a driving time are used to estimate viscous friction in the speed reducer 10 based on a result of the estimation. A manipulator 200 having a microcomputer 210 that controls driving, and a temperature estimation unit 242 that calculates a lubricant temperature estimated value that is an estimated value of the lubricant temperature is provided, and the lubricant temperature estimated value and the rotation speed are calculated. The microcomputer 210 is configured to estimate the viscous friction based on the driving time. [Selection] Figure 4

Description

  The present invention relates to a drive control device and a drive device.

  Conventionally, based on the result of estimating the viscous friction in the drive transmission mechanism based on the drive source, the drive transmission mechanism, the temperature of the lubricant in the drive transmission mechanism, the rotational speed of the drive source, and the drive time. 2. Description of the Related Art A drive control device having a control unit that controls driving is known.

  For example, the drive control device described in Patent Document 1 includes a servo motor as a drive source, a speed reducer as a drive transmission mechanism, and a servo control device as a control means. As a result of detecting the temperature by the temperature sensor, the servo controller estimates the viscous friction coefficient of the grease in the speed reducer based on the rotation speed and driving time of the servo motor, and increases or decreases the drive amount of the servo motor based on this result. . Thereby, it is supposed that the position of the controlled object can be controlled with high accuracy.

  However, in this drive control device, when controlling the drive of a manipulator, an industrial robot, or the like that requires a plurality of combinations of servo motors and speed reducers, there is a problem that the cost increases.

  In order to solve the above-described problem, the present invention provides a drive source, a drive transmission mechanism, a temperature of a lubricant in the drive transmission mechanism, a rotation speed of the drive source, and a drive time. A drive control device having control means for controlling the drive of the drive source based on a result of estimating the viscous friction, and calculating an estimated value for calculating a lubricant temperature estimated value that is an estimated value of the lubricant temperature And the control means is configured to estimate the viscous friction based on the estimated lubricant temperature, the rotational speed, and the driving time.

  According to the present invention, there is an excellent effect that it is possible to avoid an increase in cost by providing a plurality of dedicated temperature information acquisition means corresponding to each of the plurality of drive transmission mechanisms.

The figure which shows the top view which shows the arm and its periphery in the manipulator which concerns on embodiment, and an electric circuit block diagram. The side view which shows the arm and foundation in the manipulator. The external appearance top view which shows the external appearance of the input operation part in the manipulator. The block diagram which shows the structure of the electric system of the manipulator. The block diagram which shows the theoretical physical phenomenon which generate | occur | produces in the motor shaft of the motor to which electric current is supplied, and the 1st example of the arithmetic processing performed within the disturbance torque calculation part of a microcomputer. The block diagram which shows the theoretical physical phenomenon which generate | occur | produces in the motor shaft of the motor to which electric current is supplied, and the 2nd example of the arithmetic processing performed within the disturbance torque calculation part. The block diagram for demonstrating the flow of the PID control of the motor by a drive control part. The schematic diagram which shows an example of operation | movement of an arm. The graph which shows the relationship between the torque (force) when implement | achieving the operation | movement shown by FIG. 8, and the position of an arm. The graph which shows the relationship between a torque target value, a torque command value, and disturbance torque. The flowchart which shows an example of the processing flow of assist control performed by the drive control apparatus of the manipulator. The graph which shows the relationship between the viscous friction coefficient C of the grease in case grease temperature T is 1st saturation temperature Ta, the rotational speed (omega) of a motor, and drive time t. The graph which shows the relationship between the viscous friction coefficient C of grease, rotation speed (omega), and drive time t in case grease temperature T is 2nd saturation temperature Tb higher than 1st saturation temperature Ta. The graph which shows the relationship between the frictional force F with grease, rotational speed (omega), and drive time t when the grease temperature T is the 1st saturation temperature Ta. The graph which shows the relationship between the frictional force F with grease, rotational speed (omega), and drive time t in case grease temperature T is the 2nd saturation temperature Tb. The graph which shows the relationship between the viscous friction coefficient C of grease, the combination of rotational speed (omega), and grease temperature T, and the drive time t. The graph which shows the relationship between the viscous friction coefficient C of grease, the combination of rotation amount and grease temperature T, and rotation amount. For each of the two sections obtained by dividing the time zone of the driving time t into two, the viscous friction coefficient C of the grease, the rotational speed ω, and the grease temperature T when the multi-order function is approximated to a linear function The graph which shows the relationship between a combination and rotational speed (omega). Combination of the viscous friction coefficient C of the grease, the rotation amount, and the grease temperature T when the multi-order function expression is approximated to the linear function expression for each of the two sections obtained by dividing the time zone of the driving time t into two. And a graph showing the relationship between the rotation amount. For each of the three sections obtained by dividing the time zone of the driving time t into three, the viscous friction coefficient C of the grease, the rotational speed ω, and the grease temperature T when the multi-order function is approximated to a linear function The graph which shows the relationship between a combination and rotational speed (omega). A combination of the viscous friction coefficient C of the grease, the rotation amount, and the grease temperature T when the multi-order function expression is approximated to a linear function expression for each of the three sections obtained by dividing the time zone of the drive time t into three. And a graph showing the relationship between the rotation amount. The graph which shows an example of the relationship of the behavior of the viscous friction coefficient C in the case of decelerating the rotational speed (omega) on the way, the drive time t, and rotational speed (omega). The graph which shows an example of the relationship of the behavior of the viscous friction coefficient C in the case of decelerating the rotational speed (omega) on the way, the rotation amount of a motor, and rotational speed (omega). The graph which shows an example of the relationship of the behavior of the viscous friction coefficient C in the case of speeding up the rotational speed (omega), the drive time t, and rotational speed (omega). The graph which shows an example of the relationship between the behavior of the viscous friction coefficient C, the rotation amount of the motor, and the rotation speed ω when the rotation speed ω is increased halfway. The graph which shows an example of the relationship between the speed change pattern of rotational speed (omega), the viscous friction coefficient C, and the drive time t. The flowchart which shows the process flow in the 1st example of the calculation process of the viscous friction coefficient estimated value C 'implemented by a drive control apparatus. The flowchart which shows the process flow in the 2nd example of the calculation process of the viscous friction coefficient estimated value C 'implemented by a drive control apparatus. Graph showing the viscous friction coefficient C, and the first example of the relationship between the drive stopping time t _off of the motor 105. Graph showing the viscous friction coefficient C, and the second example of the relationship between the drive stopping time t _off of the motor 105. The figure which put in order the graph which shows the relationship between the viscous friction coefficient C (or viscous friction coefficient estimated value C '), time, and the example of operation | movement of a motor, and the graph which shows the relationship between rotational speed (omega), and time. The graph which shows the relationship between a viscous friction coefficient, time, and the behavior of a motor. The flowchart which shows the processing flow of the update process of the viscous friction coefficient estimated value C 'implemented during the motor drive stop implemented by a drive control apparatus. The flowchart which shows the processing flow of the flag set process implemented by a drive control apparatus. The block diagram for demonstrating the calculation method of the grease temperature estimated value T 'in a drive control apparatus. The graph which shows the 1st example of the relationship between grease temperature T, the drive state of a motor, and time. The graph which shows the 2nd example of the relationship between grease temperature T, the drive state of a motor, and time. The graph which shows the 1st example of the relationship between grease temperature T, drive time t, and rotational speed (omega). The graph which shows the 2nd example of the relationship between grease temperature T, drive time t, and rotational speed (omega). The block diagram which shows the structure of the electric system of the manipulator which concerns on a 1st Example. The block diagram for demonstrating the calculation method of the grease temperature estimated value T 'in the drive control apparatus of the manipulator. The block diagram which shows the structure of the electric system of the manipulator which concerns on a 2nd Example. The block diagram for demonstrating the calculation method of the grease temperature estimated value T 'in the drive control apparatus of the manipulator. The graph which shows grease temperature T, motor temperature TM, and the relationship of the drive state of a motor. The graph which shows the 1st example of the relationship between grease temperature T, motor temperature TM, rotational speed (omega), and the drive state of a motor. 46 is a graph showing a relationship among a grease temperature T, a motor temperature TM, a rotation speed ω, and a motor driving state in the second example in which the disturbance torque is increased as compared with the first example shown in FIG. The graph which shows the 3rd example of the relationship between grease temperature T, motor temperature TM, rotational speed (omega), and the drive state of a motor. The graph which shows the 4th example of the relationship between grease temperature T, motor temperature TM, rotational speed (omega), and the drive state of a motor. The block diagram for demonstrating the calculation method of the grease temperature estimated value T 'in the drive control apparatus of the manipulator which concerns on a 3rd Example. The graph which shows the relationship between the saturation temperature of grease, and the electric current value supplied to a motor. The figure which added the graph of the time-dependent change of the electric current value which flows into a motor to the graph of FIG. The figure which added the graph of the time-dependent change of the electric current value which flows into a motor to the graph of FIG. The figure which added the graph of the time-dependent change of the electric current value which flows into a motor to the graph of FIG. The figure which added the graph of the time-dependent change of the electric current value which flows into a motor to the graph of FIG. The block diagram for demonstrating the calculation method of the grease temperature estimated value T 'in the drive control apparatus of the manipulator which concerns on 4th Example. The graph which shows the relationship between motor temperature TM, the electric current value supplied to a motor, motor rotational speed (omega), ambient temperature, and the drive state of a motor. The graph which shows the relationship between the electric current value supplied to a motor, ambient temperature, and rotational speed (omega). The graph which shows the relationship between the electric current value supplied to a motor, the saturation temperature of grease, rotational speed (omega), and temperature difference (DELTA) T.

Hereinafter, an embodiment of a manipulator will be described as a drive device to which the present invention is applied.
First, a basic configuration of the manipulator 200 according to the embodiment will be described. FIG. 1 is a plan view showing an arm 101 and its periphery and a block diagram of an electric circuit in a manipulator 200 according to the embodiment. FIG. 2 is a side view showing the arm 101 and the base 102 in the manipulator 200. In these drawings, the manipulator 200 includes an arm 101, a base 102, a shaft member 103, an encoder 104 serving as a rotation detecting means, a motor 105 serving as a drive source, a speed reducer 106 serving as a drive transmission mechanism, and the like. Further, it also includes an electrical component 201, an input operation unit 139, various sensors 120, various switches 121, and the like. In this manipulator 200, an actuator 107 is configured by a combination of a motor 105 and a speed reducer 106.

  The drive control device of the manipulator 200 according to the embodiment includes an electrical component unit 201, an input operation unit 139, various switches 121, an encoder 104, and the like.

  The arm 101 of the manipulator 200 can rotate around a shaft member 103 provided at the end on the base side in the longitudinal direction. The shaft member 103 fixed to the end portion on the base side of the arm 101 is rotatably received by a bearing provided on the base 102.

  The shaft member 103 also serves as the drive output shaft of the speed reducer 106. The motor gear of the motor 105 fixed to the side plate of the speed reducer 106 is meshed with the gear of the speed reducer inside the speed reducer 106. When the motor 105 is rotationally driven, the rotational driving force is transmitted to the speed reducer 106. Then, the shaft member 103 that also serves as the drive output shaft of the speed reducer 106 rotates at a rotational speed that is decelerated from the rotational speed of the motor 105, and the arm 101 rotates by the rotational angle.

  The encoder 104 is attached to the rear end of the motor shaft of the motor 105 and detects the rotational speed of the motor shaft, that is, the rotational speed of the motor 105. The detection signal is sent to the electrical unit 201.

  FIG. 3 is an external plan view showing the external appearance of the input operation unit 139. The input operation unit 139 includes a touch panel 139a, a numeric keypad 139b, an execution button 139c for executing an operation start command, and a power button 139d. In addition, a stop button 139e for issuing an emergency stop command or the like is also provided.

  The user can operate the manipulator 200 by touching the touch panel 139a or pressing various keys or buttons based on the menu screen displayed on the touch panel 139a.

  FIG. 4 is a block diagram showing the configuration of the electric system of the manipulator 200. As shown in FIG. The electrical unit 201 includes a microcomputer 210, a driver board 230, a clock, a host controller 281 and the like. Image information sent from the image information input device 300 outside the manipulator 200 is sent to the microcomputer 210 via the host controller 281. The manipulator 200 can perform an operation based on the image information.

  The power supply circuit 291 outputs voltages to be supplied to the various sensors 120, the input operation unit 139, the microcomputer 210, the clock, the host controller 281, the driver board 230, and the like. Note that the voltage from the power supply circuit 291 is supplied to the encoder 104 and the motor 105 via the driver board 230.

  The driver board 230 includes a motor driver 235, a current detection unit 234, a drive information detection unit 236, and the like. The motor driver 235 outputs a current for driving the motor 105 to rotate. This current is supplied to the motor 105 while the current value is detected by the current detection unit 234 to drive the motor 105 to rotate. The encoder 104 attached to the motor shaft of the motor 105 outputs a rotation signal to the drive information detection unit 236 every time the motor shaft rotates by a predetermined rotation angle. The drive information detection unit 236 calculates the rotation speed and rotation amount of the motor shaft based on the rotation signal sent from the encoder 104, and the results are calculated as a drive control unit 213, a disturbance torque calculation unit 238 and a temperature of the microcomputer 210. It outputs to the estimation part 242.

  The host controller 281 and the microcomputer 210 are connected via a communication network. The microcomputer 210 includes a communication control unit 211 that communicates with the host controller 281, a timer unit 212 that performs timing processing, a storage unit 214 that stores various data and control programs, and the like. Further, a drive control unit 213 that controls the driving of the motor 105 via a motor driver 235 described later, a disturbance torque calculation unit 238, a temperature estimation unit 242 and the like are also provided.

  Signals from various sensors 120 and various switches 121 are input to the microcomputer 210. A clock signal transmitted from the clock is also input. Various input signals from the input operation unit 139 are also input. The user can urgently stop the operating manipulator 200 by pressing the stop button 139e of the input operation unit 139.

  While receiving the following various signals, the drive control unit 213 outputs a drive signal to the motor driver 235 of the driver board 230 according to them, thereby rotating the motor 105 with a desired torque. That is, the control program stored in the storage unit 214, various signals sent from the host controller, the rotation amount and rotation speed sent from the drive information detection unit 236, and the disturbance torque calculation unit 238 described later. The estimated disturbance torque value.

  In FIG. 1 and FIG. 2, for convenience, only one joint is shown on the arm 101, and the motor 105 and the speed reducer 106 operate the arm 101 around the one joint. However, the arm 101 is provided with a plurality of joints not shown in FIGS. 1 and 2, and the arm 101 can operate at each joint. In order to operate the arm 101 at each joint, the manipulator 200 is provided with a plurality of similar combinations in addition to the combination of the motor 105, the speed reducer 106, and the encoder 104 shown in FIGS. ing. In addition to the combination of the encoder 104, the motor 105, the speed reducer 106, and the driver board 230 shown in FIG. 4, a plurality of similar combinations for individually operating the arm 101 at each joint are provided.

  FIG. 5 is a block diagram illustrating a theoretical physical phenomenon that occurs in the motor shaft of the motor 105 to which a current is supplied, and a first example of calculation processing performed in the disturbance torque calculation unit 238 of the microcomputer 210.

  The theoretical physics phenomenon that occurs in the motor shaft to which current is supplied is as follows. That is, a torque obtained by multiplying the current value by the torque constant Kt is generated on the motor shaft to which the current is supplied. On the other hand, Coulomb friction, inertial force (J × acceleration), gravity g (θ), viscous frictional force (C × speed), and the like are generated. Theoretically, a value (actual torque) obtained by subtracting the disturbance torque from the torque based on the current value and the torque constant Kt is generated with the same value as the reciprocal of the inertial force (J × acceleration). Then, the motor shaft rotates by an angle θ obtained by multiplying the integral value of this value (1 / s: integral notation in Laplace conversion) by the rotation speed ω of the motor shaft.

  The disturbance torque calculation unit 238 calculates a Coulomb friction force, an inertia force estimation value (J ′ × acceleration), a viscous friction force estimation value (a value obtained by multiplying the current value received from the current detection unit 234 by the torque constant estimation value Kt ′. A value obtained by subtracting the sum of C ′ × speed) and gravity g (θ) is calculated as a disturbance torque estimated value. For the torque constant estimated value Kt ′ reflecting the error and the inertia moment estimated value J ′, for example, statistical multiple regression analysis or frequency response analysis is performed on the theoretical value using experimental data, for example. And ask. Further, the disturbance torque calculation unit 238 obtains the disturbance torque estimated value as an angle θ corresponding to the disturbance torque. In the figure, for the sake of convenience, the block diagram describing the theoretical physical phenomenon is described as if there is a signal input of the acceleration a, the rotational speed ω, and the angle θ toward the disturbance torque calculation unit 238. Actually, the signal input is performed by the drive information detector 236.

  FIG. 6 is a block diagram illustrating a theoretical physical phenomenon that occurs in the motor shaft of the motor 105 to which a current is supplied, and a second example of arithmetic processing performed in the disturbance torque calculation unit 238 of the microcomputer 210. In the first example shown in FIG. 5, the disturbance torque calculation unit 238 does not have a low-pass filter, whereas in the second example shown in FIG. 6, the disturbance torque calculation unit 238 has a low-pass filter. .

  The theoretical physical phenomenon in FIG. 6 is the same as the theoretical physical phenomenon in FIG. The disturbance torque calculation unit 238 shown in FIG. 6 uses a value obtained by multiplying the current value sent from the current detection unit 234 by the torque constant estimated value Kt ′ and the inertial force estimated value (J ′ × acceleration) as a time constant τ. Add the value divided by. Then, the result of subtracting the viscous frictional force estimated value (C ′ × speed), gravity g (θ), and Coulomb frictional force from the addition result is pseudo-differentiated (1 / (sτ + 1)) by a low-pass filter. . From this result, a result obtained by subtracting a value obtained by dividing the inertial force estimated value (J ′ × acceleration) by the time constant τ is obtained as a disturbance torque estimated value.

  FIG. 7 is a block diagram for explaining the flow of PID control of the motor 105 by the drive control unit 213. The drive control unit 213 generates torque substantially the same as the torque target value by PID control using the torque target value calculated based on information sent from the host controller 281 or the like and the disturbance torque estimated value. A torque command value is generated. The result is output to the motor driver 235. Thereby, it is possible to generate substantially the same torque as the torque target value on the motor shaft. In the figure, an example in which the above-described second example is adopted as the disturbance torque calculation unit 238 is shown.

  FIG. 8 is a schematic diagram illustrating an example of the operation of the arm 101. FIG. 9 is a graph showing the relationship between the torque (force) and the position of the arm 101 when realizing the operation shown in FIG. In these figures, the force (torque command value) required for the operation of the arm 101 is the torque target value calculated based on the movement amount of the arm 101 and the disturbance torque estimated value calculated by the disturbance torque calculating unit 238. It is required as a combined force. Since a part of the force required for the operation is supplemented by the force based on the estimated disturbance torque, position control following the target value can be performed with high accuracy.

  FIG. 10 is a graph showing the relationship between the torque target value, the torque command value, and the disturbance torque. As shown in the figure, by adopting a profile that gives a dead band to the torque target value, the arm 101 can be prevented from suddenly operating or oscillating, and the arm can be operated stably. 101 can be moved.

  FIG. 11 is a flowchart illustrating an example of a processing flow of assist control performed by the drive control device according to the embodiment. When the drive control device drives the motor 105 to rotate by outputting the torque command value (step 1: hereinafter, “step” is referred to as “S”), the drive control device detects the rotational speed of the motor 105 (S2) or calculates an estimated disturbance torque value. (S3). Then, it is determined whether or not the position of the arm 101 needs to be adjusted based on the rotational speed change amount, the disturbance torque estimated value change amount, and the like (S4). If it is determined that adjustment is not necessary (N in S4), the process flow is looped to S2 described above.

  On the other hand, if it is determined that torque adjustment is necessary (Y in S4), then an error in rotational speed is calculated (S5), and an additional torque command value is calculated based on the result (S6). Then, the torque command value is output (S7). Thereafter, after detecting the rotational speed of the motor 105 (S8), an estimated disturbance torque is calculated (S9). Then, based on the amount of change in the rotational speed of the motor 105, the amount of change in the estimated disturbance torque, etc., it is determined whether or not fine adjustment is necessary for the position of the arm 101 (S10). Thereafter, if fine adjustment is necessary (Y in S10), the process flow is looped to S5 described above. On the other hand, when fine adjustment is not necessary (N in S10), a series of processing flow is finished.

  The viscous friction coefficient C indicates the viscosity of grease applied in the speed reducer 106. Grease has a network structure, and the structure changes when sheared. In the speed reducer 106, when the various gears in the speed reducer 106 are rotationally driven, the grease is sheared and the structure gradually changes, so the viscosity of the grease decreases as the drive time increases. In addition, since the viscosity changes depending on the temperature in addition to the shear rate of the grease, the viscous friction coefficient C is not proportional to the rotation speed and exhibits nonlinear characteristics. Thus, in a mechanism including grease, the viscosity of the grease (viscous friction coefficient C) changes according to time, speed, and temperature.

  FIG. 12 is a graph showing the relationship among the viscous friction coefficient C of the grease, the rotational speed ω of the motor 105, and the drive time t of the motor 105 when the grease temperature T is the first saturation temperature Ta. As shown in the figure, when the grease temperature T is the same (constant at the first saturation temperature Ta in the illustrated example), the viscous friction coefficient C decreases as the rotational speed ω increases. Further, as the driving time t becomes longer (t0 <t1 <t∞), the viscous friction coefficient C becomes smaller.

  FIG. 13 shows the viscous friction coefficient C of the grease, the rotational speed ω of the motor 105, and the driving time t of the motor 105 when the grease temperature T is the second saturation temperature Tb higher than the first saturation temperature Ta. It is a graph which shows the relationship. As can be seen from the comparison between FIG. 12 and FIG. 13, if the combination of the driving time t and the rotational speed ω is the same, the higher the grease temperature, the smaller the viscous friction coefficient C.

  In FIG. 12 and FIG. 13, C0 indicates the initial value of the viscous friction coefficient C. Since t0 indicates that the drive time t is zero, when the drive time is t0, the viscous friction coefficient C remains C0.

  FIG. 14 is a graph showing the relationship between the frictional force F caused by the grease, the rotational speed ω of the motor 105, and the driving time t of the motor 105 when the grease temperature T is the first saturation temperature Ta. As shown in the figure, if the grease temperature T is the same temperature, the frictional force F increases as the rotational speed ω of the motor 105 increases. Further, the frictional force F becomes smaller as the driving time of the motor 105 becomes longer. This is because the viscous friction coefficient C decreases as the driving time t increases. As the rotational speed ω increases, the frictional force F increases, but the viscous friction coefficient C decreases.

  FIG. 15 is a graph showing the relationship between the frictional force F caused by grease, the rotational speed ω of the motor 105, and the driving time t of the motor 105 when the grease temperature T is the second saturation temperature Tb. From the comparison between FIG. 14 and FIG. 15, if the combination of the driving time t and the rotation speed is the same, the frictional force F decreases as the grease temperature T increases. This is because the viscous friction coefficient C decreases as the grease temperature T increases.

  The characteristics of FIGS. 12 to 15 vary in the slope of the graph depending on the type of grease. However, the same type of grease has the same characteristics, and the characteristics can be specified by experiments in advance. .

  In order to calculate the disturbance torque estimated value, it is necessary to calculate the viscous friction coefficient estimated value C ′. As shown in FIGS. 12 and 13, the viscous friction coefficient C includes the grease temperature T, the rotational speed ω. And the drive time t. Of these three parameters, the rotation speed ω can be detected by the encoder 104. The driving time t can be measured by the timer unit 212. The remaining parameter is the grease temperature T. If the grease temperature T is known, it is possible to obtain the estimated viscous friction coefficient value C ′ based on the previously specified characteristics such as FIGS.

  One method of knowing the grease temperature T is to provide a temperature sensor that detects the temperature of the speed reducer 106. This is because the overall temperature of the speed reducer 106 is substantially the same as the grease temperature T. However, as described above, in the manipulator 200 according to the embodiment, the combination of the encoder, the motor, and the speed reducer (104, 105, 106), which are only shown one by one in FIGS. A plurality of joints are individually provided for each joint. For this reason, a plurality of dedicated temperature sensors are required to individually detect the temperatures of the individual reduction gears, which increases costs.

  Next, a characteristic configuration of the manipulator 200 according to the embodiment will be described. The drive control device of the manipulator 200 according to the embodiment obtains the grease temperature T in each of the individual reduction gears (106) as the estimated grease temperature T '. The method will be described in detail later.

  Before describing in detail how to obtain the estimated grease temperature T ′, a method for obtaining the estimated viscous friction coefficient C ′ in the grease of each reduction gear will be described in detail.

  FIG. 16 is a graph showing the relationship between the grease friction coefficient C, the combination of the rotational speed ω and the grease temperature T, and the drive time t. As shown in the figure, when the combination of the rotational speed ω and the grease temperature T is different, the graph (characteristic) indicating the relationship between the viscous friction coefficient C and the driving time t is different. Assume that the characteristics corresponding to each of various combinations of the combination of the rotational speed ω and the grease temperature T are examined in advance by experiments. Then, based on the detection result of the rotational speed ω, the grease temperature T, and the graph (characteristic) corresponding to the combination, the viscous friction coefficient estimated value C ′ can be obtained. Hereinafter, the relationship between the viscous friction coefficient C (or the viscous friction coefficient estimated value C ′) and the driving time t (or the rotation amount) for the combination of the rotational speed ω and the grease temperature T (or the grease temperature estimated value T ′). An algorithm that represents a characteristic indicating is called a degradation characteristic algorithm. This is because the algorithm shows the characteristic of a decrease in the viscous friction coefficient as the driving time t increases.

  The storage unit 214 of the microcomputer 210 indicates the characteristics of the amount of decrease in the viscous friction coefficient C as the driving time t increases for each of a plurality of combinations of the rotational speed ω and the grease temperature T (or the estimated grease temperature T ′). The degradation characteristic algorithm shown is stored. Those degradation characteristic algorithms are obtained by a prior experiment. The algorithm format may be a multi-order function expression showing each graph of FIG. 16, or may be a data table system storing viscous friction coefficients C corresponding to each driving time t.

  The driving time t and the rotation amount of the motor calculated based on the output from the encoder are correlated. Therefore, instead of calculating the viscous friction coefficient estimated value C ′ based on the driving time t, the viscous friction coefficient estimated value C ′ may be calculated based on the rotation amount. In this case, as shown in FIG. 17, a decrease characteristic algorithm that indicates a decrease amount of the viscous friction coefficient C accompanying an increase in the rotation amount may be stored in the storage unit 214.

  For the purpose of reducing the data storage amount or increasing the calculation speed, the storage unit 214 may store a multi-order function expression of a degradation characteristic algorithm approximated to a linear function expression. For example, as shown in FIG. 18, the time zone of the driving time t is divided into two sections: a section having a driving time t0 or more and less than the driving time tx and a section having a driving time tx or more. May be approximated to a linear function expression. When the rotation amount is adopted instead of the driving time t, as shown in FIG. 19, the rotation amount region is similarly divided into two sections, and a multi-order function expression is expressed for each section as a linear function. You may approximate the equation. Further, as shown in FIG. 20, the time zone of the drive time t is divided into a section of the drive time t0 or more and less than the drive time tx, a section of the drive time tx or more and less than the drive time ty, and a section of the drive time ty or more. The multi-order function formula may be approximated to a linear function formula for each section. Even when the rotation amount is adopted instead of the driving time t, as shown in FIG. 21, the rotation amount region is similarly divided into three sections, and a multi-order function expression is linearized for each section. It may be approximated to a function expression.

  When the rotation drive of the motor 105 is stopped, the viscous friction coefficient C of the grease in the speed reducer 106 increases as the drive stop time increases. An increase characteristic algorithm indicating an increase characteristic of the viscous friction coefficient C accompanying an increase in the drive stop time at this time is specified by a previous experiment and stored in the storage unit 214.

  When the drive of the motor 105 is stopped, the drive control device calculates the increase amount of the viscous friction coefficient C based on the drive stop time counted by the timer unit 212 and the above-described increase characteristic algorithm. And the process which adds a calculation result to the viscous friction coefficient C until then and updates the viscous friction coefficient C is implemented regularly.

  FIG. 22 is a graph showing an example of the relationship between the behavior of the viscous friction coefficient C, the driving time t, and the rotational speed ω when the rotational speed ω of the motor 105 is decelerated halfway. In the grease whose characteristic of the viscous friction coefficient C is shown in this graph, when the rotational speed ω is ω1, the amount of decrease in the viscous friction coefficient C from the initial value C0 is saturated at C1 when the driving time t increases to some extent. When the rotational speed ω is ω3 slower than ω1, when the drive time t is increased to some extent, the amount of decrease from the initial value C0 of the viscous friction coefficient C is saturated at C3 smaller than C1.

  In the figure, immediately after the start of driving, the motor 105 rotates at the rotational speed ω1, and the decreasing amount of the viscous friction coefficient C gradually increases as the driving time t increases. Thereafter, when the driving time t reaches t1, the rotational speed ω is changed from ω1 to ω3 slower than ω1. At a timing slightly earlier than this, the amount of decrease in the viscous friction coefficient C is saturated at C1 corresponding to the rotational speed ω1. Therefore, the amount of decrease in the viscous friction coefficient C when the driving time t reaches t1 is C1. At this time, the rotational speed ω is changed from ω1 to ω3 slower than this, but the saturation value of the decrease amount of the viscous friction coefficient C at w3 is C3 smaller than the current decrease amount C1. For this reason, for a while after the rotational speed ω is changed to ω3, the amount of decrease in the viscous friction coefficient C gradually decreases as the drive time t increases, and then saturates at the saturation value C3. . In the storage unit 214, an algorithm indicating the relationship between the drive time t after switching when the rotational speed ω is switched to a slower value on the way and the increase amount of the viscous friction coefficient C is also obtained for various rotational speeds ω. I remember it. Therefore, even if the drive control device switches the rotation speed ω to a slower value on the way, the drive control device can obtain the amount of decrease after the switching.

  FIG. 23 is a graph showing an example of the relationship between the behavior of the viscous friction coefficient C, the amount of rotation of the motor 105, and the rotational speed ω when the rotational speed ω of the motor 105 is decelerated halfway. When the amount of decrease in the viscous friction coefficient C is obtained based on the rotation amount instead of the driving time t, the following algorithm may be stored in the storage unit 214 for various rotation speeds ω. That is, as shown in the graph after the drive time t = t1 in the figure, the relationship between the rotation amount after switching and the increase amount of the viscous friction coefficient C when the rotation speed ω is switched to a slower value on the way. It is an algorithm which shows.

  FIG. 24 is a graph illustrating an example of the relationship between the behavior of the viscous friction coefficient C, the driving time t, and the rotational speed ω when the rotational speed ω of the motor 105 is increased halfway. In the grease whose characteristic of the viscous friction coefficient C is shown in this graph, when the rotational speed ω is ω1, the amount of decrease in the viscous friction coefficient C from the initial value C0 is saturated at C1 when the driving time t increases to some extent. When the rotational speed ω is ω4 faster than ω1, when the drive time t is increased to some extent, the amount of decrease from the initial value C0 of the viscous friction coefficient C is saturated at C4 larger than C1.

  In the figure, immediately after the start of driving, the motor 105 rotates at the rotational speed ω1, and the decreasing amount of the viscous friction coefficient C gradually increases as the driving time t increases. Thereafter, when the drive time t reaches t1, the rotational speed ω is changed from ω1 to ω4 faster than ω1. At a timing slightly earlier than this, the amount of decrease in the viscous friction coefficient C is saturated at C1 corresponding to the rotational speed ω1. Therefore, the amount of decrease in the viscous friction coefficient C when the driving time t reaches t1 is C1. At this time, the rotational speed ω is changed from ω1 to ω4 faster than this. When the rotational speed ω is ω4, the saturation value of the decrease amount of the viscous friction coefficient C is ω4 lower than the current C1. For this reason, when the rotational speed ω is changed to ω4, the drive control device switches the degradation characteristic algorithm to be used from the one corresponding to ω1 to the one corresponding to ω4. Then, the amount of decrease in the viscous friction coefficient C thereafter is obtained based on the decrease characteristic algorithm after switching.

  FIG. 25 is a graph showing an example of the relationship between the behavior of the viscous friction coefficient C, the amount of rotation of the motor 105, and the rotational speed ω when the rotational speed ω of the motor 105 is increased halfway. When the amount of decrease in the viscous friction coefficient C is obtained based on the rotation amount instead of the driving time t, the following may be performed. That is, as shown in the graph after the drive time t = t1 in the figure, the relationship between the amount of rotation after switching and the amount of decrease in the viscous friction coefficient C when the rotational speed ω is switched to a faster ω4 on the way. May be stored in the storage unit 214.

  FIG. 26 is a graph showing an example of the relationship between the speed change pattern of the rotational speed ω, the viscous friction coefficient C, and the drive time t. In the same figure, the example which employ | adopted the 1st speed change pattern and the 2nd speed change pattern as a speed change pattern is shown. In any speed change pattern, the rotational speed ω is changed from ω1 to a slower ω3 before the amount of decrease in the viscous friction coefficient C reaches the saturation value.

  In the first speed change pattern, the amount of decrease in the viscous friction coefficient C does not reach the saturation value (C1) when the rotational speed ω = ω1, and the saturation value (C3) when the rotational speed ω = ω3. Is larger than the rotational speed ω, the rotational speed ω is decelerated from ω1 to ω3. For this reason, the amount of decrease in the viscous friction coefficient C after deceleration decreases for a while as the drive time t increases, and eventually saturates at the saturation value (C3) corresponding to ω3.

  In the second speed change pattern, when the amount of decrease in the viscous friction coefficient C does not increase to the saturation value (C3) when the rotational speed ω = ω3, the rotational speed ω is decelerated from ω1 to a slower ω3. Yes. For this reason, the amount of decrease in the viscous friction coefficient C after deceleration continues to increase as the drive time t increases, and eventually saturates at the saturation value (C3) corresponding to ω3.

  FIG. 27 is a flowchart illustrating a processing flow in the first example of the viscous friction coefficient estimation value C ′ calculation process performed by the drive control device. The drive control apparatus that has started this calculation process first obtains the initial value of the viscous friction coefficient estimated value C ′ (S1), and then determines whether or not the drive of the motor 105 has started (S2). If driving has not started, the step S1 and the step S2 are repeated. When the driving of the motor 105 is started (Y in S2), the timer unit 212 starts the timing process of the driving time t (S3), and then acquires the driving time t from the timer unit 212 (S4). Based on this acquisition result and past acquisition results, it is determined whether or not a certain time has elapsed since the previous viscous friction coefficient estimated value C ′ was updated (S5). (N in S5) loops the process flow to S4. On the other hand, when the predetermined time has elapsed (Y in S5), the rotational speed ω of the motor 105 is calculated based on the output signal from the encoder 104 (S6). Thereafter, a decrease amount of the viscous friction coefficient estimated value C ′ is calculated based on the driving time t, the rotational speed ω, and the grease temperature estimated value T ′, and the calculated result is subtracted from the viscous friction coefficient estimated value C ′. The viscous friction coefficient estimated value C ′ is updated. After the update, it is determined whether or not the driving of the motor 105 is finished (S8). If not finished (N in S8), the process flow is looped to S4. On the other hand, when it is finished (Y in S8), the calculation process is finished.

  A method for obtaining the estimated grease temperature value T ′ will be described later.

  FIG. 28 is a flowchart illustrating a processing flow in the second example of the calculation processing of the viscous friction coefficient estimation value C ′ performed by the drive control device. This second example has the same processing flow as the first example except for the points to be noted next. That is, in step S6, the rotation amount is calculated instead of the rotation speed ω. In step S7, the amount of decrease in the viscous friction coefficient estimated value C ′ is calculated based on the drive time t, the rotation amount doctor, and the grease temperature estimated value T ′, and the calculated result is used as the viscous friction coefficient estimated value. The viscous friction coefficient estimated value C ′ is updated by subtracting from C ′.

FIG. 29 is a graph showing a first example of the relationship between the viscous friction coefficient C and the drive stop time t _off of the motor 105. The drive stop time t _off is a time during which the stop state is continuously maintained after the drive of the motor 105 is stopped. The initial value C0 of the viscous friction coefficient C in the figure is the value of the viscous friction coefficient C (or the estimated viscous friction coefficient C ′) when the driving of the motor 105 is stopped. As shown in the figure, the viscous friction coefficient C is provided with an upper limit value _Cmax . This upper limit C _max is set according to the type of grease.

  The viscous friction coefficient estimated value C ′ is added to the previous value (including the initial value C0) by the increase amount of the viscous friction coefficient C calculated based on the increase characteristic algorithm described above and the drive stop time toff. It will be updated. While the driving of the motor 105 is stopped, the viscous friction coefficient estimation value C ′ is periodically updated by periodically updating the motor 105.

  If the increase characteristic algorithm described above stores a non-linear characteristic, as shown in the figure, the viscous friction coefficient estimated value C ′ during the drive stop (in FIG. The time-varying characteristic of C) becomes a non-linear characteristic. On the other hand, when an increase characteristic algorithm indicating a linear characteristic is stored, as shown in FIG. 30, the temporal change characteristic of the viscous friction coefficient estimation value C ′ during the drive stop becomes a linear characteristic. .

  FIG. 31 is a graph showing the relationship between the viscous friction coefficient C (or estimated viscous friction coefficient C ′), time, and an operation example of the motor 105, and the relationship between the rotational speed ω of the motor 105 and time. The graphs shown are arranged. The former graph shows a correction function for the viscous friction coefficient C (or the estimated viscous friction coefficient C ').

In the first operation example in the figure, the motor 105 rotated at the rotational speed ω = ω1 is stopped, and the stop is maintained for the first drive stop time t _off 1, and then the motor 105 is rotated at the rotational speed ω = ω1. Rotate.

In the second operation example, the motor 105 that has been rotated at the rotational speed ω = ω2 is stopped (ω1> ω2), and the stop is stopped for a second drive stop time t longer than the first drive stop time t _off 1. Keep _off 2 only. Thereafter, the motor 105 is rotated at the rotational speed ω = ω1.

  As illustrated, the correction function differs between the first operation example and the second operation example. This is because the initial value C0 of the viscous friction coefficient C when the driving of the motor 105 is resumed differs depending on the difference in the rotational speed ω before the motor 105 stops.

FIG. 32 is a graph showing the relationship between the viscous friction coefficient, time, and the behavior of the motor 105. As shown in the figure, when the motor 105 is driven, the viscous friction coefficient C decreases as the driving time t increases. However, when the drive time t increases to a certain extent, the decrease reaches saturation. On the other hand, when the motor 105 is stopped, the viscous friction coefficient C increases as the drive stop time t _off increases. However, when the drive stop time t _off increases to some extent, the increase reaches saturation.

  After the drive of the motor 105 is started, the drive control device uses a degradation characteristic algorithm corresponding to the combination of the rotational speed ω and the grease temperature estimated value T ′ at that time (for example, the combination of ω1 and Ta in FIG. 16). The viscous friction coefficient estimated value C ′ is updated. Specifically, the amount of decrease in the viscous friction coefficient estimated value C ′ is calculated using the above-described decrease characteristic algorithm, and the result is subtracted from the previous viscous friction coefficient estimated value C ′ to obtain the viscous friction coefficient estimated value C ′. 'Update. Perform this update regularly.

  Further, after the drive of the motor 105 is stopped, a process of updating the viscous friction coefficient estimated value C ′ is periodically performed using an increase characteristic algorithm corresponding to the grease temperature estimated value T ′ at that time. Specifically, the increase amount of the viscous friction coefficient estimated value C ′ is calculated by using the above-described increase characteristic algorithm, and the result is added to the previous viscous friction coefficient estimated value C ′ to calculate the viscous friction coefficient estimated value. Update C '.

FIG. 33 is a flowchart showing a processing flow of the update processing of the viscous friction coefficient estimation value C ′ performed by the drive control device while the motor drive is stopped. When the drive control device stops driving the motor 105 (Y in S1), after obtaining the initial value of the viscous friction coefficient estimated value C ′ (S2), it waits for a predetermined time to elapse (N in S3). ). When a predetermined time has elapsed (Y in S3), an increase characteristic algorithm corresponding to the estimated grease temperature value T ′ is read from the storage unit 214, and the viscous friction coefficient is determined based on the read result and the drive stop time t _off. An increase amount of the estimated value C ′ is calculated (S4). The viscous friction coefficient estimated value C ′ is updated by adding the calculation results (S5). Thereafter, when the driving of the motor 105 is not started (N in S6), the process flow is looped to S3, and the viscous friction coefficient estimated value C ′ is continuously updated. On the other hand, when the drive of the motor 105 is started (Y in S6), the updating process in FIG.

  FIG. 34 is a flowchart showing a processing flow of flag setting processing performed by the drive control device. When the estimation execution is set by the user's input operation to the input operation unit 139 (Y in S1), the drive control device sets the estimation flag. On the other hand, when the estimation execution is not set (N in S1), the estimation flag is canceled.

  So far, the aspect of obtaining the disturbance torque based on the result of calculating the viscous friction coefficient estimated value C ′ has been described, but the drive control apparatus adopts this aspect when the estimation flag is set. When the estimation flag is not set, the default value stored in the storage unit 214 is used as the viscous friction coefficient estimated value C ′ instead of using the calculated result.

FIG. 35 is a block diagram for explaining a method of calculating an estimated grease temperature value T ′ in the drive control device. In the figure, the temperature estimation unit 242 includes a temperature change amount estimation circuit 242a, a temperature estimation circuit 242b, and the like. When ambient temperature information is input to the input operation unit 139 by a user input operation, the information is stored in the storage unit 214. On the other hand, the rotational speed ω and the drive time t (or drive stop time t _off ) calculated by the drive information detection unit 236 are input to the temperature change amount estimation circuit 242a. The temperature change amount estimation circuit 242a calculates a grease temperature change amount estimated value based on the rotation speed ω and the drive time t (or drive stop time t _off ), and outputs the grease temperature change amount estimate value to the temperature estimation circuit 242b. The temperature estimation circuit 242b updates the grease temperature estimated value T ′ by adding the temperature change amount estimated value, and outputs the result. The ambient temperature is the temperature of air within a short distance range that can affect the temperature change of the grease with respect to the speed reducer 106, for example, the temperature of air within a range of several centimeters from the surface of the speed reducer 106. It is.

FIG. 36 is a graph showing a first example of the relationship between the grease temperature T, the driving state of the motor 105, and time. In the figure, when driving of the motor 105 is started, the grease temperature T rises from the initial value T0 as the driving time t increases, and eventually reaches the saturation temperature Ta. Thereafter, when the driving of the motor 105 is stopped, the grease temperature T gradually decreases from the saturation temperature Ta as the driving stop time t _off increases, and eventually decreases to the initial value T0.

  FIG. 37 is a graph showing a second example of the relationship between the grease temperature T, the driving state of the motor 105, and time. Unlike the first example, it is assumed that the drive start and stop of the motor 105 are repeated a plurality of times before the grease temperature T rises to the saturation temperature Ta as in the second example. It is assumed that the total amount of increase in the grease temperature T during driving is larger than the total amount of decrease in the grease temperature T during stoppage during the repetition period. In this case, as shown in the figure, the grease temperature T becomes relatively symptomatic with the passage of time, and eventually reaches the saturation temperature Ta.

  The temperature estimating unit 242 sequentially updates the grease temperature estimated value T ′ by adding the amount of increase in the grease temperature T during driving, or sequentially calculates the grease temperature estimated value T ′ by subtracting the amount of decrease in the grease temperature T during stopping. Or update.

FIG. 38 is a graph showing a first example of the relationship between the grease temperature T, the driving time t of the motor 105, and the rotational speed ω of the motor 105. As shown in the figure, when driving of the motor 105 is started, the grease temperature T gradually increases from the initial value T0 as the driving time t increases. As the rotational speed ω increases, the increase rate of the grease temperature T increases and the saturation temperature increases. In the figure, the rotational speed ω has a magnitude relationship of ω1 <ω2. The saturation temperature Ta is a value when the rotational speed ω = ω1, whereas the saturation temperature Tb is a value when the rotational speed ω = ω2. If the ambient temperature is constant, and if the initial value T0 of the grease temperature T is the same as the ambient temperature, even if the rotation stop time t _offf of the motor 105 is increased, the initial value T0 of the grease temperature T is Maintains the same value as the ambient temperature without change (constant).

  FIG. 39 is a graph showing a second example of the relationship among the grease temperature T, the driving time t of the motor 105, and the rotational speed ω of the motor 105. In the same figure, the graph of ω = 0 shows the change with time of the grease temperature T when the motor 105 is not driven. On the other hand, the graphs of ω1 and ω2 indicate the change with time of the grease temperature T after the motor 105 starts driving at the time point t0. For this reason, the horizontal axis of the graph of ω = 0 indicates time, whereas the horizontal axis of the graphs of ω1 and ω2 indicates the drive time t. As shown in the graph of ω = 0, even when the motor 105 is stopped driving, if the ambient temperature gradually increases with time, the grease temperature T is increased from the initial value T0. It rises little by little. As shown in FIG. 38, when the ambient temperature is constant without changing over time (FIG. 38), the grease temperature T when the motor 105 is stopped (ω = 0) remains at the initial value T0. Maintained constant. On the other hand, as shown in FIG. 39, even when the motor 105 is stopped (ω = 0), as the ambient temperature rises with time, the grease temperature T rises from the initial value T0 accordingly. I will do it.

In the storage unit 214, the rising characteristic algorithm indicating the relationship between the driving time t and the amount of increase of the grease temperature T from the initial value T0 shown in FIG. 38 differs depending on the ambient temperature. Also, the descent characteristic algorithm showing the relationship between the drive stop time t _off and the amount of descent of the grease temperature T from the initial value T0 also varies depending on the ambient temperature.

Therefore, the storage unit 214 includes the following as an increase characteristic algorithm indicating the relationship between the drive time t and the amount of increase of the grease temperature T from the initial value T0, as shown by T′ω1 and T′ω2 shown in FIG. I remember something like this. That is, a plurality of ascending characteristics algorithms corresponding to combinations of a plurality of rotational speeds (for example, ω1, ω2) and ambient temperature. A plurality of algorithms corresponding to each of a plurality of ambient temperatures are stored as a descending characteristic algorithm indicating the relationship between the drive stop time t _off and the amount of decrease of the grease temperature T from the initial value T0.

In an indoor environment in which the ambient temperature (room temperature) hardly varies within a day as in a product assembly room in a factory, the initial value T0 in the motor stop state as shown in FIG. 39 hardly changes from room temperature. That is, if the grease temperature T is substantially the same as the room temperature, the initial value T0 during the drive stop is maintained at the initial value T0 regardless of the increase in the drive stop time t _off as shown in FIG. The manipulator 200 according to the embodiment is used in such an indoor environment.

Therefore, when the motor 105 is stopped, the drive control device reads the one corresponding to the ambient temperature setting value from among the plurality of descending characteristic algorithms stored in the storage unit 214. Then, the drive stop time t _off is substituted into the descent characteristic algorithm to calculate the fall amount of the grease temperature T (grease temperature fall amount estimated value), and the initial value T0 is sequentially updated by subtracting the calculation result. This process is performed periodically.

  During driving of the motor 105, among the plurality of rising characteristic algorithms stored in the storage unit 214, the algorithm corresponding to the combination of the ambient temperature setting value and the rotation speed ω is read from the storage unit 214. Then, the drive time t is substituted into the increase characteristic algorithm to calculate the increase amount of the grease temperature T (grease temperature increase estimation value), and the grease temperature estimation value T ′ is sequentially updated by adding the calculation results. This process is performed periodically.

  In such a configuration, the estimated viscous friction coefficient C for each reducer is provided without providing a plurality of dedicated temperature sensors for individually detecting the temperatures of the respective reducers in the plurality of actuators corresponding to the respective joints. 'Can be calculated. Therefore, an increase in cost due to the provision of a plurality of dedicated temperature sensors can be avoided. Furthermore, since it is not necessary to provide an ambient temperature sensor for detecting the ambient temperature, an increase in cost due to the ambient temperature sensor can be avoided.

  Next, the manipulator 200 of each example in which a more characteristic configuration is added to the manipulator 200 according to the embodiment will be described. Unless otherwise specified, the configuration of the manipulator 200 according to each example is the same as that of the embodiment.

[First embodiment]
FIG. 40 is a block diagram showing a configuration of the electric system of the manipulator 200 according to the first embodiment. In the manipulator 200 according to the second embodiment, an ambient temperature sensor 141 for detecting the ambient temperature is provided.

FIG. 41 is a block diagram for explaining a method of calculating the estimated grease temperature value T ′ in the drive control device for the manipulator 200 according to the first embodiment. While the motor 105 is stopped, the temperature estimation unit 242 reads a plurality of descending characteristics algorithms stored in the storage unit 214 corresponding to the detection result of the ambient temperature by the ambient temperature sensor 141. Then, the drive stop time t _off is substituted into the descent characteristic algorithm to calculate the fall amount of the grease temperature T (grease temperature fall amount estimated value), and the initial value T0 is sequentially updated by subtracting the calculation result. This process is performed periodically.

  During driving of the motor 105, among the plurality of rising characteristic algorithms stored in the storage unit 214, the algorithm corresponding to the combination of the detection result of the ambient temperature and the rotational speed ω is read from the storage unit 214. Then, the drive time t is substituted into the increase characteristic algorithm to calculate the increase amount of the grease temperature T (grease temperature increase estimation value), and the grease temperature estimation value T ′ is sequentially updated by adding the calculation results. This process is performed periodically.

  In such a configuration, the estimated grease temperature T ′ can be calculated without requiring the user to input ambient temperature information. Moreover, even in an indoor environment where there is a daily fluctuation of the ambient temperature, the estimated grease temperature T ′ reflecting the daily fluctuation can be accurately obtained.

  The “circuit” in each block in the temperature estimation unit 242 may be an electric circuit or a theoretical circuit based on a program.

[Second Example]
In a configuration in which the distance between the motor 105 and the speed reducer 106 is relatively short, the grease temperature T is more susceptible to the temperature of the motor 105 than the ambient temperature. This is also the case with the manipulator 200 according to the second embodiment.

  FIG. 42 is a block diagram illustrating a configuration of an electric system of the manipulator 200 according to the second embodiment. FIG. 43 is a block diagram for explaining a method of calculating the estimated grease temperature value T ′ in the drive control device for the manipulator 200 according to the second embodiment.

  In the manipulator 200 according to the second embodiment, a plurality of motor temperature sensors 151 that individually detect the temperatures of the plurality of motors 105 are provided. These are used for urgently stopping the operation of the manipulator 200 when the temperature reaches a predetermined upper limit value for each of the plurality of motors 105.

In the drive control apparatus according to the second embodiment, the estimated grease temperature T ′ is calculated based on the detection result of the motor temperature by the motor temperature sensor 151. Specifically, when the motor 105 is stopped, the one corresponding to the detection result of the motor temperature by the motor temperature sensor 151 among the plurality of descending characteristic algorithms stored in the storage unit 214 is read. Then, the drive stop time t _off is substituted into the descent characteristic algorithm to calculate the decrease amount of the grease temperature T (the estimated value of the grease temperature decrease amount), and the initial value T0 is sequentially updated by subtracting the calculation result. . This process is performed periodically. When the motor 105 is rotating, the algorithm corresponding to the detection result of the motor temperature by the motor temperature sensor 151 among the plurality of rising characteristic algorithms stored in the storage unit 214 is read. Then, the drive time t is substituted into the increase characteristic algorithm to calculate the increase amount of the grease temperature T (the estimated value of the grease temperature increase amount), and the current value is sequentially updated by adding the calculation results. This process is repeated periodically.

  FIG. 44 is a graph showing the relationship between the grease temperature T, the motor temperature TM, and the driving state of the motor 105. In the figure, an example in which the motor 105 is driven at a rotational speed ω of ω1 is shown. As shown in the figure, the grease temperature T decreases at a certain rate with respect to the motor temperature TM. For example, when the initial value T0 of the grease temperature T is the same as the room temperature, the grease temperature T can be obtained by the equation “T = T0 + TM × A (1−exp (−at))”. In this equation, A is an attenuation factor (0 <A <1), and a is a coefficient (a> 0). As in the first embodiment, a term that takes into account the amount of increase in grease temperature T due to friction (estimated amount of increase in grease temperature) may be provided in this equation.

  FIG. 45 is a graph showing a first example of the relationship among the grease temperature T, the motor temperature TM, the rotational speed ω of the motor 105, and the driving state of the motor 105. As illustrated, even if the motor temperature TM is the same, the grease temperature T varies depending on the rotational speed ω of the motor 105. This is because the rising speed of the grease temperature T increases as the rotational speed of the motor 105 increases. In the figure, the relationship is ω1 <ω2.

  46 shows the grease temperature T, the motor temperature TM, the rotational speed ω of the motor 105, and the driving state of the motor 105 in the second example in which the disturbance torque applied to the motor 105 is increased compared to the first example shown in FIG. It is a graph which shows the relationship. As shown in the figure, the greater the disturbance torque, the higher the grease temperature T for the combination of the same rotational speed ω and the same drive time t.

  FIG. 47 is a graph showing a third example of the relationship among the grease temperature T, the motor temperature TM, the rotational speed ω, and the driving state of the motor 105. In the figure, the motor temperature TM1 is the motor temperature of the motor 105 on which a predetermined disturbance torque is acting. In the figure, motor temperatures TM1 and TM1 'are temperatures of the motor 105 on which the same disturbance torque acts. The reason why the rate of temperature increase per unit time is different from each other even though disturbance torques of the same magnitude are acting is that the rotational speed ω is different. The motor temperature TM1 is the temperature of the motor 105 that rotates at the rotational speed ω = ω1 (ω1 <ω2). On the other hand, the motor temperature TM1 'is the temperature of the motor 105 that rotates at the rotational speed ω = ω2. Since ω1 <ω2, the rate of temperature increase per unit time is higher at the motor temperature TM1 'than at the motor temperature TM1.

  The estimated motor temperature T′M1ω1 is an estimated value of the motor temperature TM1 of the motor 105 that rotates at the rotational speed ω = ω1. The estimated motor temperature T′M1′ω2 is an estimated value of the motor temperature TM1 ′ of the motor 105 that rotates at the rotational speed ω = ω2. Since the disturbance torques are the same, the rate of temperature increase per unit time is higher for the estimated motor temperature T′M1′ω2 having a higher rotational speed ω than for the estimated motor temperature T′M1ω1. .

  FIG. 48 is a graph showing a fourth example of the relationship among the grease temperature T, the motor temperature TM, the rotational speed ω, and the driving state of the motor 105. In the figure, the motor temperature TM1 is the motor temperature TM of the motor 105 rotating at a rotational speed ω = ω1 while receiving a load of a predetermined disturbance torque. The motor temperature TM2 is the motor temperature TM of the motor 105 that is rotating at the rotational speed ω = ω1 while receiving a load of disturbance torque larger than the disturbance torque. Although the rotational speeds ω are the same, the motor temperature TM2, which is the motor temperature TM when receiving a greater disturbance torque load, has a higher rate of temperature increase per unit time than the motor temperature TM1. ing.

  The estimated motor temperature T′M1ω1 is an estimated value of the motor temperature TM of the motor 105 rotating at the rotational speed ω = ω1 while receiving a load of a predetermined disturbance torque. The estimated motor temperature T′M2ω1 is an estimated value of the motor temperature TM of the motor 105 rotating at the rotational speed ω = ω1 while receiving a load of disturbance torque larger than the disturbance torque. Since the latter is subjected to a larger disturbance torque load, the motor temperature estimated value T′M2ω1 is the unit than the motor temperature estimated value T′M1ω1 despite the same rotational speed ω. The rate of temperature rise per hour is high.

  As described above, the estimated motor temperature T′M has a temperature rise characteristic corresponding to the combination of the disturbance torque and the rotational speed ω.

  In view of this, the storage unit 214 stores an algorithm indicating characteristics of an increase in the estimated grease temperature T ′ with an increase in the driving time t for each combination of disturbance torque and rotational speed ω of various values. . While the motor 105 is being driven, the drive control device reads an algorithm corresponding to the combination from the storage unit 214 and substitutes the drive time t into the algorithm, thereby increasing the increase amount of the grease temperature T (the estimated value of the grease temperature increase). ) Is calculated. And the process which adds a calculation result to grease temperature estimated value T 'and updates grease temperature estimated value T' is implemented regularly.

[Third embodiment]
In the manipulator 200 according to the third embodiment, neither the ambient temperature sensor that detects the ambient temperature nor the motor temperature sensor that detects the motor temperature is provided. Similar to the manipulator 200 according to the embodiment, the drive control device grasps the ambient temperature by using the ambient temperature information input to the input operation unit 139 by the user and stored in the storage unit 214.

  FIG. 49 is a block diagram for explaining a method of calculating the estimated grease temperature T ′ in the drive control device for the manipulator 200 according to the third embodiment. In the figure, the temperature estimation unit 242 includes a motor temperature change amount estimation circuit 242c in addition to the temperature change amount estimation circuit 242a and the temperature estimation circuit 242b. The current value detected by the current detection unit 234 is input to the motor temperature change amount estimation circuit 242c.

The motor temperature change amount estimation circuit 242c estimates the amount of temperature increase of the motor 105 based on the current value received from the current detection unit 234 and the drive time t received from the drive information detection unit 236 while the motor 105 is being driven. Calculate the estimated motor temperature rise value. Further, when the motor 105 is stopped, an estimated motor temperature decrease amount is calculated based on the drive stop time t _off received from the drive information detection unit 236, the latest drive time t, and the like. The estimated motor temperature rise amount and the estimated motor temperature fall amount calculated by the motor temperature change amount estimation circuit 242c are sent to the temperature estimation circuit 242b.

The rotational speed ω and the drive time t (or drive stop time t _off ) calculated by the drive information detection unit 236 are input to the temperature change amount estimation circuit 242a. The temperature change amount estimation circuit 242a calculates a grease temperature change amount estimated value based on the rotation speed ω and the drive time t (or drive stop time t _off ), and outputs the grease temperature change amount estimate value to the temperature estimation circuit 242b. The temperature estimation circuit 242b generates a new grease based on the previous grease temperature estimation value T ′, the estimated temperature change amount resind from the motor temperature change amount estimation circuit 242c, and the ambient temperature read from the storage unit 214. An estimated temperature value T ′ is obtained.

  FIG. 50 is a graph showing the relationship between the saturation temperature of the grease and the current value supplied to the motor 105. The initial temperature in the figure is the same as the room temperature. That is, the graph of the figure shows the following grease temperature T as the saturation temperature. That is, after the motor 105 has started driving after being stopped for a sufficient time to lower the grease temperature T to substantially the same temperature as the room temperature, a sufficient time has passed to raise the grease temperature T to the saturation temperature. This is the later grease temperature T. If the motor 105 continues to rotate for a sufficient time, the grease temperature T will eventually rise to the saturation temperature. As shown in the figure, a correlation is established between the saturation temperature and the current value flowing through the motor 105.

The graphs of FIGS. 51, 52, 53, and 54 are graphs of time-dependent changes in the value of the current flowing through the motor 105 in addition to the graphs of FIGS. 45, 46, 47, and 48. As shown in these figures, a certain relationship is established between the value of the current flowing through the motor 105 and the motor temperature TM. A relational expression indicating this relation (obtained by a prior experiment) is stored in the storage unit 214. The motor temperature change amount estimation circuit 242c calculates a motor temperature increase estimated value and a motor temperature decrease estimated value based on the relational expression, the drive time t and the drive stop time _toff, and the calculation results are used as the temperature estimation circuit. It outputs to 242b.

[Fourth embodiment]
FIG. 55 is a block diagram for explaining a method of calculating the estimated grease temperature T ′ in the drive control device for the manipulator 200 according to the fourth embodiment. In the figure, the temperature estimation unit 242 includes an ambient temperature estimation circuit 242d in addition to a temperature variation estimation circuit 242a, a temperature estimation circuit 242b, and a motor temperature variation estimation circuit 242c.

The ambient temperature estimation circuit 242d calculates an ambient temperature estimation value based on the current value sent from the current detection unit 234, the drive time t sent from the drive information detection unit 236, the drive stop time _{toff, and the} like.

  The temperature estimation circuit 242b receives the following three pieces of information. That is, the estimated grease temperature change amount sent from the temperature change amount estimation circuit 242a, the estimated motor temperature change amount (rising amount or descending amount) sent from the motor temperature change amount estimation circuit, and the ambient temperature estimation circuit This is the estimated ambient temperature sent from. The temperature estimation circuit calculates a grease temperature estimated value T ′ based on these three pieces of information.

  FIG. 56 is a graph showing the relationship among the motor temperature TM, the current value supplied to the motor 105, the rotational speed ω of the motor 105, the ambient temperature, and the driving state of the motor 105. In the figure, the motor temperature TM is the motor temperature when the motor 105 rotates under the conditions of ambient temperature = T0 and rotational speed ω = ω1. The motor temperature TM ′ is a motor temperature when the motor 105 rotates under the conditions of the ambient temperature = T0 ′ and the rotational speed ω = ω1. Note that T0 <T0 '. Even if the motor 105 rotates at the same rotational speed ω = ω1 for the same drive time t, the motor temperature TM when rotating in the environment where the ambient temperature is T0, and the environment T0 ′ higher than that by ΔT. In the case of the motor temperature TM ′ when rotating at, the latter is higher. Then, since the latter raises the grease temperature T and lowers the grease viscosity, the value of the current flowing through the motor 105 becomes smaller as shown in the figure.

When the drive stop time t _off of the motor 105 becomes longer than a predetermined stop threshold, the grease temperature T in the speed reducer 106 becomes substantially the same as the ambient temperature. Therefore, the current value of the motor 105 immediately after the start of driving in this state is a value corresponding to the ambient temperature and the rotational speed ω.

The storage unit 214 stores the following data table. That is, this is a data table in which the data relating the ambient temperature to the combination of the current value and the rotational speed ω immediately after the start of driving with the drive stop time t _off larger than the stop threshold is stored for various combinations.

When the driving of the motor 105 is started from a state where the drive stop time t _off is larger than the stop threshold, the ambient temperature estimation circuit 242d obtains the ambient temperature corresponding to the combination of the current value and the rotational speed ω immediately after the above data. Identify from the table. Then, the specific result is output as the ambient temperature.

  Instead of the data table, a graph showing the relationship between the current value and the ambient temperature as shown in FIG. 57 is stored for the number of various rotational speeds ω, and the graph according to the actual rotational speed ω is stored. The ambient temperature may be obtained by substituting the current value.

  Ta in the figure is the saturation temperature of the motor temperature TM when the motor 105 is driven under a combination of ambient temperature = T0 and rotational speed ω = ω1. Ta ′ is the saturation temperature of the motor temperature TM when the motor 105 is driven under the combination of ambient temperature = T0 ′ and rotational speed ω = ω1. If the driving time t of the motor 105 becomes long enough to reliably raise the motor temperature to the saturation temperature regardless of the ambient temperature, the motor temperature may be regarded as reaching the saturation temperature. That is, when the drive time t exceeds a predetermined operation threshold, the motor temperature TM is almost saturated.

The storage unit 214 stores a plurality of graphs (function formulas) shown in FIG. 58 in association with various rotational speeds ω. The ambient temperature estimation circuit 242d starts driving the motor 105 from a state where the drive stop time t _off is larger than a predetermined operation threshold, and then updates the ambient temperature when the drive time exceeds the operation threshold. Do. Specifically, among the plurality of graphs, the graph corresponding to the rotational speed ω at that time is read. Then, the saturation temperature is obtained by substituting the current value into the graph. Since the difference ΔT between the ambient temperature and the saturation temperature corresponding to the graph is known in advance, the ambient temperature is calculated by subtracting the difference ΔT from the saturation temperature. Then, the ambient temperature is updated to the same value as the calculation result.

What was demonstrated above is an example, and there exists an effect peculiar for every following aspect.
[Aspect A]
In the aspect A, the driving source (for example, the motor 105), the driving transmission mechanism (for example, a reduction gear), the temperature of the lubricant in the driving transmission mechanism, the rotational speed of the driving source, and the driving time (for example, the driving time t) Based on the result of estimating the viscous friction (for example, the viscous friction coefficient estimated value C ′) in the drive transmission mechanism based on the drive control device (for example, the microcomputer 210) that controls the drive of the drive source (for example, An electrical component 201, an input operation unit 139, various switches 121, and an encoder 104), and an estimated value calculating means for calculating a lubricant temperature estimated value that is an estimated value of the temperature of the lubricant (for example, grease). For example, a temperature estimation unit 242) is provided, and the viscosity is estimated based on the lubricant temperature estimated value (for example, grease temperature estimated value T ′), the rotation speed, and the driving time. To estimate the friction, it is characterized in that constitutes the control means.

  In the aspect A, it is possible to avoid an increase in cost due to the provision of a plurality of dedicated temperature information acquisition means corresponding to each of the plurality of drive transmission mechanisms for the reason described below. That is, in Patent Document 1, there is no specific description of what temperature is detected by the temperature sensor, but there is a description that the viscous friction of the lubricant changes depending on the temperature of the lubricant. Therefore, it is considered that the temperature sensor detects the temperature of the lubricant. In such a configuration, when controlling the driving of a manipulator or the like that requires a plurality of drive transmission mechanisms, dedicated temperature detection means (temperature information acquisition means) for individually detecting the temperature of each drive transmission mechanism is provided. Providing a plurality increases the cost. On the other hand, in the aspect A, since the viscous friction is estimated based on the estimated lubricant temperature estimated by the estimated value calculating means, it is necessary to provide a plurality of temperature sensors individually corresponding to each of the drive transmission mechanisms. Absent. Therefore, it is possible to avoid an increase in cost due to the provision of a plurality of dedicated temperature information acquisition means corresponding to each of the plurality of drive transmission mechanisms.

[Aspect B]
Aspect B provides temperature information acquisition means (for example, input operation unit 139, ambient temperature sensor 141) for acquiring information on the ambient temperature of the drive transmission mechanism in aspect A, and the lubricant temperature is based on the ambient temperature. The estimated value calculating means is configured to calculate an estimated value, and a plurality of combinations of the rotational speed and the lubricant temperature estimated value are used as the viscous friction lowering characteristic algorithm as the driving time increases. Are stored in advance, and the one corresponding to the combination of the actual rotational speed and the estimated lubricant temperature is selected and used for the estimation of the viscous friction. As described above, the control means is configured. In such a configuration, the estimated lubricant temperature is calculated as follows. That is, the temperature of the lubricant generally increases with an increase in driving time according to an increasing characteristic according to a combination of temperature information such as ambient temperature and the rotational speed of the driving source. Therefore, if a rising characteristic according to an actual combination is selected from a plurality of rising characteristics according to various combinations and used for estimating the estimated lubricant temperature, the temperature of the lubricant can be accurately estimated. Is possible.

[Aspect C]
Aspect C is the aspect B, in which the viscous friction increase characteristic algorithm according to an increase in the drive stop time (for example, drive stop time t _off ) of the drive source is stored in advance, and the decrease corresponding to the actual combination The control means is configured to estimate the viscous friction based on a characteristic algorithm, the drive time, the increase characteristic algorithm, and the drive stop time. In such a configuration, in addition to the amount of decrease in viscous friction accompanying an increase in drive time, the amount of increase in viscous friction accompanying an increase in drive stop time is taken into account to estimate viscous friction, so that only the amount of decrease is taken into account It is possible to estimate viscous friction more accurately than.

[Aspect D]
Aspect D provides a current detection means (for example, current detection unit 234) for detecting a current supplied to the drive source in aspect B or C, and based on the current in addition to the viscous friction, The control means is configured to control the above. In such a configuration, the position of the driven object can be accurately brought close to the target position as compared with the configuration in which the drive source is controlled based on only the viscous friction and the viscous friction.

[Aspect E]
Aspect E is characterized in that in any one of Aspects B to D, as the temperature information acquisition means, an input operation means for performing an input operation of the ambient temperature information input by an operator is used. is there. In such a configuration, the estimated lubricant temperature can be estimated without providing an ambient temperature sensor for detecting the ambient temperature.

[Aspect F]
Aspect F is characterized in that, in any one of Aspects B to D, an ambient temperature detecting means for detecting the ambient temperature is used as the temperature information acquisition means. In such a configuration, it is possible to estimate the lubricant temperature estimated value without requiring the user to input the ambient temperature.

[Aspect G]
Aspect G provides a driving source temperature detecting means (for example, a motor temperature sensor 151) for detecting a driving source temperature, which is the temperature of the driving source, instead of providing the temperature information input means in any of the aspects B to D. The estimated value calculation means is configured to calculate the ambient temperature based on the drive source temperature. In such a configuration, the estimated lubricant temperature value can be estimated using the detection result of the drive source temperature by the drive source temperature detection means.

[Aspect H]
Aspect H uses input operation means in which the input operation of the ambient temperature information input by an operator is performed as the temperature information acquisition means in aspect D, and based on the rotation speed and the current The estimated value calculation means is configured to estimate a drive source temperature, which is a temperature of the drive source, and to calculate the lubricant temperature estimated value based on the information of the drive source temperature and the ambient temperature. To do. In such a configuration, the estimated lubricant temperature is more accurate than the configuration in which the estimated lubricant temperature is estimated based only on the input value of the ambient temperature among the estimated value of the drive source temperature and the input value of the ambient temperature. Can be estimated.

[Aspect I]
Aspect I is aspect D, and instead of providing the temperature information acquisition means, the drive source temperature, which is the temperature of the drive source, is estimated based on the rotation speed and the current, while the rotation speed And the estimated value calculating means is configured to estimate the lubricant temperature estimated value based on the drive source temperature and the ambient temperature after estimating the ambient temperature based on the current. It is. In such a configuration, the estimated lubricant temperature value can be estimated without providing an input value of the ambient temperature by the user or an ambient temperature detecting means for detecting the ambient temperature.

[Aspect J]
Aspect J is a driving device (for example, manipulator 200) including a driving control device and a controlled object (for example, arm 101) whose driving is controlled by the driving control device. Any of the above is used.

104: Encoder (part of the drive control device, rotation detection means)
105: Motor (drive source)
106: Reducer (drive transmission mechanism)
137: Motor temperature sensor (temperature information acquisition means)
139: Input operation unit (temperature information acquisition means, input operation means)
141: Ambient temperature sensor (temperature information acquisition means)
210: Microcomputer (control means)
234: Current detection unit (current detection means)
242: Temperature estimation unit (estimated value calculation means)
C ′: Estimated viscous friction coefficient t: Drive time t _off : Drive stop time

Japanese Patent No. 4453526

Claims (10)

The drive source, the drive transmission mechanism, the temperature of the lubricant in the drive transmission mechanism, the rotational speed and the drive time of the drive source, and the result of estimating the viscous friction in the drive transmission mechanism based on the result of the estimation. A drive control device having a control means for controlling drive,
Estimated value calculating means for calculating a lubricant temperature estimated value that is an estimated value of the lubricant temperature is provided,
The drive control device characterized in that the control means is configured to estimate the viscous friction based on the lubricant temperature estimated value, the rotation speed, and the drive time. The drive control apparatus according to claim 1,
Providing temperature information acquisition means for acquiring information of the ambient temperature of the drive transmission mechanism;
Configuring the estimated value calculation means to calculate the lubricant temperature estimated value based on the ambient temperature;
In addition, as the viscous friction lowering characteristic algorithm accompanying the increase in the driving time, a plurality of lowering characteristic algorithms corresponding to each of a plurality of combinations of the rotational speed of the driving source and the lubricant temperature estimated value are stored in advance, The control means is configured to select one corresponding to a combination of the actual rotational speed and the lubricant temperature estimated value from among the reduction characteristic algorithms and use it for the estimation of the viscous friction. Drive control device. The drive control device according to claim 2,
An increase characteristic algorithm of the viscous friction with an increase in the drive stop time of the drive source is stored in advance, the decrease characteristic algorithm corresponding to the actual combination, the drive time, the increase characteristic algorithm, and the drive stop A drive control device, wherein the control means is configured to estimate the viscous friction based on time. In the drive control device according to claim 2 or 3,
Providing a current detection means for detecting a current supplied to the drive source;
The drive control apparatus according to claim 1, wherein the control means is configured to control the drive source based on the current in addition to the viscous friction. In the drive control device according to any one of claims 2 to 4,
As the temperature information acquisition means, an input operation means for performing an input operation of the ambient temperature information is used. In the drive control device according to any one of claims 2 to 4,
A drive control device using ambient temperature detection means for detecting the ambient temperature as the temperature information acquisition means. In the drive control device according to any one of claims 2 to 4,
Instead of providing the temperature information acquisition unit, a drive source temperature detection unit that detects a drive source temperature that is the temperature of the drive source is provided, and the estimated value calculation is performed so as to calculate the ambient temperature based on the drive source temperature. A drive control device comprising means. The drive control apparatus according to claim 4, wherein
As the temperature information acquisition means, using an input operation means for performing an input operation of the ambient temperature information input by an operator,
And, the drive source temperature, which is the temperature of the drive source, is estimated based on the rotation speed and the current, and the lubricant temperature estimated value is calculated based on the information on the drive source temperature and the ambient temperature, A drive control device comprising the estimated value calculation means. The drive control device according to claim 4,
Instead of providing the temperature information acquisition means,
The drive source temperature, which is the temperature of the drive source, is estimated based on the rotation speed and the current, while the ambient temperature is estimated based on the rotation speed and the current, and then the drive source temperature and the ambient temperature are calculated. The drive control device characterized in that the estimated value calculation means is configured to estimate the lubricant temperature estimated value based on the estimated value. In a drive device comprising a drive control device and a controlled object whose drive is controlled by the drive control device,
A drive apparatus using the drive control apparatus according to claim 1 as the drive control apparatus.

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