JP2009098720A - Reaction force application type input device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a reaction force application type input device for securing the operability of an operating member even when the temperature of an actuator fluctuates. <P>SOLUTION: A microcomputer calculates an amount of change in the heat generation temperature of a motor based on supply power to the motor in a determined arithmetic cycle, and calculates the current heat generation temperature of the motor by adding the amount of change in the heat generation temperature obtained this time to the previously obtained heat generation temperature of an actuator. Then, the microcomputer adjusts the supply power to the motor based on the obtained heat generation temperature, and suppresses the fluctuation in an operation reaction to be applied to a knob due to the temperature change of the motor. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a reaction force applying type input device that applies an operation reaction force according to an operation state to an operation member such as a knob.

2. Description of the Related Art Conventionally, for example, a reaction force applying type input device as shown in Patent Document 1 is known. The input device detects a rotation angle of a knob rotated by a user with a rotary encoder, controls a motor to apply a predetermined operation reaction force to the knob according to the detected rotation angle, and A control device is provided that outputs an operation signal corresponding to the rotation angle of the knob to an electrical device that is an operation target of the knob. The input device is mounted on a vehicle, for example, and is used to adjust the air volume of the car air conditioner as the electric device and the volume of the car audio, etc. through the rotation operation of the knob. For example, when adjusting the air volume of a car air conditioner, if the knob is rotated in the direction to increase the air volume, a rotational force in the direction opposite to the rotation direction of the knob is applied to the knob as an operation reaction force through the motor. The motor is controlled so that the rotational force in the direction opposite to the rotational direction applied to the knob increases as the angle increases. Thereby, the user can grasp | ascertain how much the knob was rotated to the direction which increases an air volume by the resistance touch accompanying the increase in the reaction force given through the knob. The same applies when adjusting the volume of the car audio.
JP 2004-342019 A

  However, the conventional reaction force applying type input device has the following problems. That is, as the temperature of the motor increases, the value of the internal resistance, more precisely the electric resistance of the motor coil, increases, and accordingly, the current supplied to the motor decreases and the motor torque decreases. Conversely, as the temperature of the motor decreases, the value of the internal resistance decreases and the motor torque increases. As described above, since the motor torque increases and decreases with the temperature change of the motor, there is a concern that the operation reaction force applied to the knob becomes unstable.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a reaction force application type input device that can ensure the operability of the operation member even when the temperature of the actuator fluctuates. It is to provide.

  The invention according to claim 1 detects the operation amount of the operation member operated by the user through the operation amount detection means, and applies the predetermined operation reaction force to the operation member according to the operation amount. In the reaction force imparting type input device, the control unit includes a control unit that controls supply power and outputs an operation signal corresponding to an operation amount of the operation member to an electric device that is an input operation target of the operation member. The amount of change in the heat generation temperature of the actuator based on the power supplied to the actuator is determined at a predetermined calculation cycle, and the amount of change in the heat generation temperature obtained this time is added to the heat generation temperature of the actuator obtained last time. The current heating temperature of the actuator is obtained, and the power supplied to the actuator is adjusted based on the obtained heating temperature. To suppress the fluctuation of the operation reaction force applied to the operating member with a change in temperature of the actuator to its gist.

  According to the present invention, since the control means controls the power supplied to the actuator in accordance with the operation amount of the operation member acquired through the operation amount detection means, the power supplied to the actuator can be easily obtained. Can do. Here, in general, the power supplied to the actuator is equal to the heat generation amount (heat generation energy) of the actuator, and the heat generation amount can be obtained as a temperature change of the actuator per unit time. Therefore, the current heat generation temperature of the actuator can be calculated by numerically integrating the temperature change of the actuator per unit time, that is, by adding the amount of change in the heat generation temperature obtained this time to the heat generation temperature of the actuator previously obtained. Can be estimated.

  Here, in the actuator that is driven by the supply of electric power, the value of the internal electrical resistance increases and the output decreases as the temperature increases, and conversely, the value of the internal electrical resistance decreases as the temperature decreases. Thus, the output is increased. As described above, since the output of the actuator increases or decreases due to the temperature change, there has been a concern that the operation reaction force applied to the operation member becomes unstable. In this regard, according to the present invention, the control means adjusts the power supplied to the actuator, that is, the output of the actuator, in order to suppress the output fluctuation due to the temperature change of the actuator. Therefore, even when the temperature of the actuator fluctuates, the stability of the operation reaction force applied to the operation member, and thus the operation stability of the operation member is ensured.

  According to a second aspect of the present invention, in the reaction force imparting type input device according to the first aspect, the control means has the temperature of the actuator reaching a temperature determination threshold value determined to suppress overheating of the actuator. The gist is to reduce the power supplied to the actuator to less than the normal power to be supplied when it is determined that the temperature of the actuator has reached the temperature determination threshold.

  When electric power continues to be supplied to the actuator, such as when the operation member is repeated at short time intervals, the actuator may generate heat and may overheat. In this case, it is not only difficult to secure the required output, but there is also a concern that the actuator may burn out. In this case, since it becomes difficult to apply an operation reaction force to the operation member, the operability of the operation member is significantly reduced. Therefore, in order to suppress such overheating of the actuator, for example, when the temperature of the actuator reaches a predetermined temperature, the power supply to the actuator is cut off, and when the temperature drops below the predetermined temperature, the power supply to the actuator is not supplied. It is possible to resume. However, in this case, since the reaction force applied to the operation member is lost, the operability of the operation member is sacrificed until the temperature of the actuator drops below a predetermined temperature. In addition, when the actuator temperature drops below a predetermined temperature after the power supply to the actuator is cut off and the power supply to the actuator is resumed, an operation reaction force is suddenly applied to the operation member. Will be. This is not preferable from the viewpoint of operation stability of the operation member.

  In this regard, according to the present invention, when it is determined that the estimated temperature of the actuator has reached a predetermined temperature determination threshold value, the power supplied to the actuator is reduced from the normal power that should be supplied. Thereby, overheating of the actuator can be suppressed. Unlike the case where the supply of electric power to the actuator is interrupted, the supply of the electric power to the actuator is not interrupted, so that the operation reaction force is continuously applied to the operation member. For this reason, even when the temperature of the actuator reaches a predetermined temperature determination threshold, the operation stability of the operation member can be ensured. In addition, even when the temperature of the actuator falls below a predetermined temperature determination threshold and the power supplied to the actuator is returned to the normal power, the difference in the operation reaction force applied to the operation member before and after that is small. Therefore, the operation stability of the operation member is ensured. Thus, the actuator performance, that is, the output reduction of the actuator can be minimized while suppressing overheating of the actuator. Performance is also secured as a reaction force imparting type input device.

  According to a third aspect of the present invention, in the reaction force applying input device according to the first or second aspect of the present invention, the control means is a current calorific value of the actuator calculated based on a power supplied to the actuator. And using a function including a constant including an ambient temperature of the actuator, a heat capacity of the actuator, and a heat radiation resistance in the atmosphere of the actuator, a change amount of the heating temperature of the actuator is obtained. Is the gist.

  By using the function as shown in the present invention, the temperature change amount of the actuator can be easily obtained based on the power supplied to the actuator which can be easily grasped by the control means itself.

  According to a fourth aspect of the present invention, there is provided the reaction force applying input device according to the first or second aspect, further comprising temperature detecting means for detecting an ambient temperature of the actuator, wherein the control means The current calorific value of the actuator calculated based on the supplied power and a variable including the ambient temperature of the actuator detected through the temperature detecting means are used as arguments, and the heat capacity of the actuator and the heat dissipation resistance in the atmosphere of the actuator. The gist is to determine the amount of change in the heat generation temperature of the actuator using a function comprising a constant including

  According to the present invention, the amount of temperature change of the actuator can be obtained using the ambient temperature of the actuator at that time. For this reason, the temperature estimation accuracy of the actuator by the control means is improved.

  According to a fifth aspect of the present invention, in the reaction force applying input device according to any one of the first to fourth aspects, a current detection unit that detects a current value supplied to the actuator; and At least one of voltage detection means for detecting a voltage value applied to the actuator, wherein the control means takes into account at least one of a current value detected through the current detection means and a voltage value detected through the voltage detection means; Then, the gist is to obtain the power supplied to the actuator.

  According to the present invention, by using the measured current value and voltage value, the calculation accuracy of the power supplied to the actuator can be improved.

  According to the present invention, the operability of the operation member can be ensured even when the temperature of the actuator fluctuates.

<First Embodiment>
Hereinafter, an embodiment in which the present invention is embodied in an input device used in a display system that is an electronic device for a vehicle will be described with reference to FIGS. The display system is for operating ancillary equipment of a vehicle such as an air conditioner, an audio system and a navigation system.

<Outline of display system>
First, an overview of the display system 10 will be described. As shown in FIG. 1, the display system 10 includes a display 11 disposed in the center cluster so that the user can easily see in the passenger compartment, and a center cluster to facilitate operation by the user in the passenger compartment. An input device 12 is provided. Further, for example, the center cluster is provided with a plurality of selection switches for selecting ancillary equipment of the vehicle such as an air conditioner, an audio, and a navigation system. When any one of these selection switches is operated, the screen 11a of the display 11 displays the operation status according to the accessory device corresponding to the operated selection switch, or one or a plurality of function items. The

  For example, when a selection switch corresponding to an air conditioner is operated, the operation status, function items for temperature setting, and the like are displayed on the screen 11a. When a selection switch corresponding to the navigation system is operated, a function item such as a guidance map or destination setting is displayed on the screen 11a. The user operates the input device 12 while viewing the screen 11a, thereby selecting one function item from a plurality of function items displayed on the screen 11a and switching to a desired screen, or attaching a vehicle accessory. To make it work.

  As described above, the screen 11a displayed on the display 11 is diverse, and the number of function items displayed on various screens and their arrangement intervals are different for each screen. Input operations for these multiple types of screens 11a are shared by a single input device 12 from the viewpoint of saving the installation space of the input device and ensuring operability. In order to use the single input device 12 for multiple functions, and to enable the user to confirm the operation to some extent without visually confirming the screen 11a, the input device 12 is as follows. Configuration is adopted. That is, the input device 12 has different operation feelings depending on the number of function items displayed on the screen 11a, the arrangement interval thereof, and the like, for each function of the accessory devices such as the air conditioner and the navigation system. Is generated as a reaction force applying type input device that is applied to the user as an operation reaction force.

<Reaction force imparting type input device>
Next, the configuration of the input device 12 will be described in detail. As shown in FIG. 2, the input device 12 includes a knob 21 that is rotated by a user. The knob 21 is connected to an output shaft 23 a of a motor 23 disposed inside the center cluster via a connecting shaft 22. In addition, a rotation angle sensor 24 that detects the rotation angle of the knob 21 is provided on the connecting shaft 22 inside the center cluster. The rotation angle sensor 24 includes a slit disk 24a provided on the connecting shaft 22 so as to be integrally rotatable, and a light emitting element 24b and a light receiving element 24c disposed so as to sandwich the slit disk 24a in the thickness direction. An optical rotary encoder is employed.

  In the slit disk 24a, a plurality of slits extending in the radial direction are formed at equal intervals in the rotation direction. Then, the light emitted from the light emitting element 24b is blocked in the optical path for each pitch of the slit by rotating the connecting shaft 22 through the rotating operation of the knob 21, and the light is repeatedly transmitted and blocked in proportion to the rotation amount. It is. The light receiving element 24 c takes out the light passing through the corresponding slit as an electrical signal and outputs a rotation angle signal to the control circuit 25 as the rotation position information of the knob 21. The control circuit 25 drives the motor 23 by PWM (pulse width modulation) control so as to apply a predetermined operation reaction force to the knob 21 based on the rotation angle of the knob 21 detected through the rotation angle sensor 24. For example, when the rotation angle of the knob 21 exceeds a predetermined rotation angle, a moderation feel can be obtained as an operation reaction force by reversing the rotation force applied to the knob 21 through the motor 23.

<Electrical configuration>
Next, the electrical configuration of the input device 12 will be described. As shown in FIG. 3, a power supply circuit 32 and a motor drive circuit 33 are connected to the microcomputer 31 constituting the control circuit 25 of the input device 12. The motor drive circuit 33 is connected to the motor 23 described above, and a voltage sensor 34 and a current sensor 35 are provided on these connection paths. These voltage sensor 34 and current sensor 35 are connected to the microcomputer 31. Further, the rotation angle sensor 24 and the display 11 described above are connected to the microcomputer 31.

  The power supply circuit 32 is connected to a plus terminal of a vehicle power supply 36 such as a battery, converts the voltage (for example, 12V to 24V) of the vehicle power supply 36 into a predetermined voltage (for example, 5V), and supplies it to the microcomputer 31. When an ignition switch (not shown) provided between the power supply circuit 32 and the vehicle power supply 36 is turned on, power from the vehicle power supply 36 is supplied to the microcomputer 31 via the power supply circuit 32. When the ignition switch is turned off, power supply from the vehicle power source 36 to the microcomputer 31 is cut off.

  The motor drive circuit 33 is a PWM inverter circuit that converts a DC voltage from the vehicle power supply 36 into an AC voltage and supplies the AC voltage to the motor 23. The voltage sensor 34 detects the voltage applied to the motor 23, AD converts the voltage detection signal, and sends the signal to the microcomputer 31. The current sensor 35 detects the current supplied from the motor drive circuit 33 to the motor 23, AD-converts the current detection signal, and sends it to the microcomputer 31.

  The microcomputer 31 performs display control of the display 11 according to a display control program stored in a storage device (not shown) such as an EEPROM and a flash memory. For example, the microcomputer 31 causes the display 11 to display a plurality of function items indicating the operation contents of the specified accessory devices of the vehicle. When the selection switch is operated to switch the function of the display system 10, the microcomputer 31 changes the screen 11a of the display 11 to another screen having a different number of function items corresponding to the other switched function. Switch to. Further, the microcomputer 31 acquires the rotation angle of the knob 21 through the rotation angle sensor 24, and selects a desired function item through a visible or invisible cursor that moves on the screen 11a of the display 11 based on the rotation angle.

  Further, the microcomputer 31 controls the drive of the motor 23 according to the motor control program stored in the storage device. That is, the microcomputer 31 operates according to an operation reaction force according to the screen 11a of the switched display 11, more precisely, the number of function items on the screen 11a and their arrangement intervals, or the rotation angle of the knob 21. In order to generate a reaction force, the motor 23 is driven by PWM (pulse width modulation) control.

  More specifically, the microcomputer 31 performs PWM calculation based on the rotation angle signal from the rotation angle sensor 24, and accurately outputs to the motor drive circuit 33 to generate a PWM signal having a predetermined duty ratio based on the calculation result. Outputs a motor control signal to a plurality of switching elements such as FETs (not shown) constituting the circuit. The motor control signal output from the microcomputer 31 defines the duty ratio (on duty) of the switching element of the motor drive circuit 33.

  The motor drive circuit 33 supplies a PWM signal (more precisely, a three-phase excitation current) having a predetermined duty ratio to the motor 23 based on the motor control signal sent from the microcomputer 31. Is driven based on the PWM signal. That is, each switching element is turned on and off by applying the motor control signal to a gate terminal (not shown) of each switching element at a predetermined timing. As a result, the DC voltage of the vehicle power supply 36 is converted into a three-phase (U-phase, V-phase, W-phase) AC voltage and supplied to the motor 23. In other words, the motor 23 is driven in accordance with a pulse signal subjected to pulse width modulation, that is, the aforementioned PWM signal (voltage value). Then, the amount of current supplied to the motor 23 is adjusted by the duty ratio of the PWM signal, and the rotational speed (rotational speed) of the motor 23 is controlled.

  When the microcomputer 31 increases the rotational speed of the motor 23, the microcomputer 31 sets a large duty ratio of the PWM signal. Then, the current supplied to the motor 23 increases, and the rotational speed (rotational speed) of the motor 23 increases accordingly. Conversely, the microcomputer 31 sets the duty ratio of the PWM signal to be small when the rotational speed of the motor 23 is decreased. As a result, the current supplied to the motor 23 decreases, and the rotational speed (rotational speed) of the motor 23 decreases accordingly.

  Here, as described above, when the forward / reverse rotation of the knob 21 is repeated at a short time interval, electric power is continuously supplied to the motor 23, so there is a concern that the motor performance is deteriorated due to the heat generated by the motor 23. The Precisely, the motor coil constituting the motor 23 generates heat, and the electrical resistance of the coil increases accordingly. When the electric resistance of the coil increases, the amount of current supplied to the motor 23 decreases, and the motor torque decreases. For this reason, it is difficult to secure the required motor torque, and the operability of the knob 21 may be impaired.

  Therefore, in the present embodiment, the microcomputer 31 detects the voltage applied to the motor 23 detected through the voltage sensor 34, the current supplied to the motor 23 detected through the current sensor 35, and the duty ratio of the PWM signal described above. Based on the above, the heat generation amount (heat generation energy) of the motor 23 is estimated. The microcomputer 31 controls the motor 23 so as to increase or decrease the motor torque according to the estimated amount of heat generated by the motor 23, specifically, changes the duty ratio of the PWM signal.

<Outline of motor control>
Next, an outline of the control of the motor 23 by the microcomputer 31 in the input device configured as described above will be described with reference to the flowchart shown in FIG. This flowchart is repeatedly executed at a predetermined calculation cycle between the time when the vehicle is turned on and the time when the vehicle is turned off according to the motor control program stored in the storage device of the microcomputer 31. When the vehicle is powered off, the process of the flowchart shown in FIG. 4 is terminated. Here, it is assumed that the user performs a rotation operation of the knob 21 to select a desired function item from among a plurality of function items displayed on the screen 11a of the display 11.

  Now, when the vehicle power source 36 is turned on through the operation of an ignition switch (not shown) by the user, the microcomputer 31 performs an initialization process (step S101). That is, the microcomputer 31 sets all its internal circuits to the initial state.

  Next, the microcomputer 31 acquires a voltage detection signal (digital value) from the voltage sensor 34 and a current detection signal (digital value) from the current sensor 35 (steps S102 and S103).

Next, the microcomputer 31 obtains the current temperature T _n of the motor 23 using the fact that the electric power supplied to the motor 23 is equal to the heat generation energy of the motor 23 (step S104). That is, the electric power given to the motor 23 is obtained based on the voltage detection signal from the voltage sensor 34 and the current detection signal from the current sensor 35, and the motor 23 per unit time (exactly, the calculation cycle) The current temperature of the motor 23 is estimated by obtaining a temperature rise value for each). The temperature estimation process of the motor 23 will be described in detail later.

  Next, the microcomputer 31 obtains the value of the operation reaction force applied to the knob 21 in consideration of the heat generation temperature of the motor 23 estimated as described above, and supplies it to the motor 23 to apply the operation reaction force. The duty ratio of the PWM signal is calculated (step S105). The microcomputer 31 outputs a motor control signal to the motor drive circuit 33 so as to generate a PWM signal having the calculated duty ratio. The control of the motor 23 using the estimated temperature information of the motor 23 will be described in detail later.

  Thereafter, the microcomputer 31 determines whether or not the predetermined time Δt has elapsed (step S106). The microcomputer 31 repeats the process of step S106 when determining that the predetermined time Δt has not elapsed, and shifts the process to step S102 when determining that the predetermined time Δt has elapsed.

Thereafter, the microcomputer 31 repeats the processes in steps S102 to S106 described above until the vehicle is powered off.
<Motor temperature estimation process>
Next, in the flowchart shown in FIG. 4, the process for estimating the heat generation temperature of the motor 23 executed by the microcomputer 31 when the process proceeds to step S104 described above will be described in detail.

The microcomputer 31 estimates the heat generation temperature of the motor 23 from the electric power actually supplied to the motor 23.
Since the power P can be regarded as the heat generation energy Q, obtaining the power P is equivalent to obtaining the heat generation energy Q. In the present embodiment, since the microcomputer 31 drives the motor 23 by PWM control, the electric power P given to the motor 23 takes the following equation (A) into consideration when the duty ratio of the PWM signal is taken into account. As shown.

P = Q = I ² · Rx · D = I · V (A)
Here, V is a voltage applied to the motor 23 (operation voltage of the motor 23), I is a current supplied to the motor 23, Rx is an internal resistance of the motor 23, and D is a duty ratio (for example, 5%) of the PWM signal. .

  Incidentally, since the internal resistance Rx of the motor 23, more precisely, the electric resistance of the motor coil depends on the temperature of the motor 23, the internal resistance Rx increases as the temperature of the motor 23 increases. As a result, the value of the current I supplied to the motor 23 decreases, and the power P actually supplied to the motor 23 decreases as the temperature of the motor 23 increases. In the present embodiment, as shown in the formula (A), the electric power P applied to the motor 23 based on the current detection signal from the current sensor 35 and the voltage detection signal from the voltage sensor 34, that is, the heat generation energy of the motor 23. Since Q is obtained, it is possible to accurately obtain the electric power P applied to the motor 23, and hence the heat generation energy Q.

  In addition, when it is difficult to provide the current sensor 35 for some reason, it is also possible to do the following. That is, the relationship between the heat generation temperature of the motor 23 and the value of the internal resistance Rx is stored in advance in the storage device of the microcomputer 31 as a table, and when the heat generation energy Q is obtained, it is supplied to the motor 23 based on the table data. Estimate the value of current I.

Next, the microcomputer 31 obtains the temperature change ΔT per unit time Δt using the heat generation energy Q obtained by the equation (A).
Here, the rising temperature T _UP per unit time Δt is obtained by the following equation (B), and similarly the falling temperature T _DWN is obtained by the following equation (C).

T _UP = Q · Δt / C (B)
T _DWN = (T _n-1 −T ₀ ) · Δt / C · R (C)
Therefore, the temperature change ΔT _n [° C.] per unit time Δt for the nth time is expressed as the following equation (D).

ΔT _n = Q _n · Δt / C − (T _n−1 −T ₀ ) · Δt / C · R (D)
Here, Q _n is the heat generation energy per unit time Δt for the n-th time obtained by the above formula (A), T ₀ is the ambient temperature of the motor 23 (here, the temperature in the passenger compartment), and T _n-1 is the previous calculation. The temperature of the motor 23, C is the heat capacity of the motor 23, and R is the heat radiation resistance [° C./W] from the motor 23 to the periphery.

  The heat radiation resistance R is obtained in advance by a well-known theoretical calculation and an experiment using a vehicle model. The heat capacity C is obtained by multiplying the mass m [kg] of the motor 23 and the specific heat D [J / kg ° C.]. The heat radiation resistance R and the heat capacity C are both fixed values (constants).

In the above-described equation (D), the temperature change ΔT _n is affected by the ambient temperature T ₀ of the motor 23. In this embodiment, the ambient temperature T ₀ = 25 ° C. (constant) because it is in the vehicle interior. ). Since the heat generation temperature of the motor 23 is very high, for example, about 100 ° C. compared to the temperature in the vehicle interior, even if the ambient temperature T ₀ , which is the temperature in the vehicle interior, is fixed at about 25 ° C., the calculated temperature There is no significant effect on the change ΔT _n .

Then, as shown in the following equation (E), the temperature change ΔT _n calculated by the above equation (D) is added to the previously calculated temperature T _n−1 of the motor 23, so that The current temperature Tn is calculated.

T _n = T _n-1 + ΔT _n (E)
As described above, the microcomputer 31 estimates the current temperature T _n of the motor 23 by performing a numerical integration operation in software. Then the microcomputer 31 obtains a predetermined operation reaction force time to time by using the temperature T _n of the motor 23 estimated as described above.

In the present embodiment, the temperature change ΔT _n is obtained with the ambient temperature T ₀ as a constant value. However, the following changes may be made. That is, as indicated by a two-dot chain line in FIG. 3, a temperature sensor 41 that detects the temperature and outputs the temperature detection signal is provided in the passenger compartment. The microcomputer 31 uses the temperature in the passenger compartment detected by the temperature sensor 41 as the ambient temperature T ₀ of the above-described equation (D).

As the temperature sensor 41, for example, if the vehicle is equipped with an auto air conditioner system, the temperature sensor constituting the system can also be used. With the recent digitization of vehicles, various types of sensor information provided in vehicles can be easily obtained through an information network built in the vehicle. In this case, it is not necessary to provide a dedicated temperature sensor separately. In this manner, the temperature of the vehicle interior at that time, that is, the ambient temperature T ₀ is acquired through the temperature sensor 41, and the calculated accuracy of the temperature change ΔT _n is obtained by using the acquired ambient temperature T _0. and thus the current estimated accuracy of the temperature T _n of the motor 23 is increased.

<Motor control>
Next, in the flowchart shown in FIG. 4, the control of the motor 23 executed by the microcomputer 31 when the process proceeds to step S105 described above will be described in detail.

The microcomputer 31 controls the motor 23 as follows using the temperature information of the motor 23 estimated in step S104. For example, when the motor torque is determined by the duty ratio of the PWM signal supplied to the motor 23, the microcomputer 31 determines the motor 23 estimated as described above so as to obtain a normal motor torque at that time. The duty ratio of the PWM signal is corrected using the temperature as a coefficient. That is, the duty ratio D of the PWM signal is expressed by the following equation (F) as a function of the estimated temperature T _n of the motor 23.

Duty ratio D = f (T _n ) (F)
The microcomputer 31 sets the duty ratio D of the PWM signal required to generate the normal motor torque at that time based on the temperature of the motor 23 estimated at that time. The microcomputer 31 controls the motor drive circuit 33 so as to generate a PWM signal having a corrected duty ratio corresponding to the temperature estimated at that time.

  As described above, as the temperature of the motor 23 increases, the value of the internal resistance increases and the motor torque decreases. Conversely, as the temperature of the motor 23 decreases, the value of the internal resistance decreases and the motor torque increases. As described above, since the motor torque increases and decreases with the temperature change of the motor 23, there is a concern that the operation reaction force applied to the knob 21 becomes unstable. Although the motor 23 having a certain margin in performance is adopted, as described above, the driving power is supplied to the motor 23 as in the case where the forward / reverse rotation of the knob 21 is repeated at a short time interval. If the supply continues, there is a possibility that the heat generation of the motor coil proceeds and an overheated state is reached. In this case, it is not only difficult to secure the required motor torque, but there is also a concern that the motor 23 may burn out.

  In this regard, as described above, in the present embodiment, the motor 23 is increased or decreased by increasing or decreasing the duty ratio of the PWM signal supplied to the motor 23 based on the current temperature of the motor 23, that is, the power supplied to the motor 23. The change in motor torque due to the temperature change is suppressed. Therefore, the operational stability of the knob 21 is ensured. In other words, the performance deterioration of the motor 23 due to the continuous operation of the knob 21, that is, the reduction of the motor torque accompanying the temperature rise can be suppressed.

  Further, the microcomputer 31 determines whether or not the temperature of the motor 23 estimated in step S104 described above has reached a temperature determination threshold value that is set to suppress overheating of the motor 23. When the microcomputer 31 determines that the temperature of the motor 23 has reached the temperature determination threshold, the microcomputer 31 reduces the motor torque, that is, the power supplied to the motor 23 from the normal power that should be supplied at that time. .

  Specifically, a predetermined motor control signal is output to the motor drive circuit 33 so that the duty ratio of the PWM signal supplied to the motor 23 is smaller than the regular duty ratio at that time. In this case, although the specification value is not satisfied, it is preferable to reduce the motor torque to the extent that the usability is not affected. In this way, by reducing the power supplied to the motor 23, the temperature rise of the motor 23 is suppressed, and problems such as seizure of the motor 23 are avoided. Moreover, although the normal motor torque at that time, that is, the operation reaction force to the knob 21 cannot be secured, since the operation reaction force is continuously applied to the knob 21, the operability of the knob 21 is also secured to some extent. The

  Here, it is assumed that the knob 21 is rotated by the user in order to select a desired function item from among a plurality of function items displayed on the screen 11a of the display 11. When the rotational angle of 21 exceeds a predetermined rotational angle, a rotational force opposite to the rotational operation direction of the knob 21 by the user is given through the motor 23. Thus, every time a function item on the screen 11a is selected by displacing the cursor on the screen 11a through the rotation operation of the knob 21, an operation reaction force is applied to the knob 21. For this reason, when the user selects a function item on the screen 11a, the operability of the knob 21 is preferably ensured. Further, as described above, the operational reaction force applied to the knob 21 does not vary according to the temperature of the motor 23, so that the operational stability of the 21 is ensured.

<Effect of Embodiment>
Therefore, according to the present embodiment, the following effects can be obtained.
(1) The microcomputer 31 obtains the amount of change in the heat generation temperature of the motor 23 based on the power supplied to the motor 23 at a predetermined calculation cycle, and obtains the amount of change in the heat generation temperature obtained this time of the actuator obtained last time. The current heat generation temperature of the motor 23 is obtained by adding to the heat generation temperature. Then, the microcomputer 31 adjusts the power supplied to the motor 23 based on the obtained heat generation temperature so as to suppress the fluctuation of the operation reaction force applied to the knob 21 due to the temperature change of the motor 23. did.

Since the microcomputer 31 controls the power supplied to the motor 23 in accordance with the operation amount (rotation angle) of the knob 21 acquired through the rotation angle sensor 24, the power supply to the motor 23 is easily obtained. be able to. Here, in general, the power supplied to the motor 23 is equal to the heat generation amount (heat generation energy) of the motor 23, and the heat generation amount can be obtained as a temperature change of the motor 23 per unit time. Therefore, the amount of change in temperature of the motor 23 per unit time is calculated by numerical integration, that is, the amount of change in the heat generation temperature obtained this time (temperature change ΔT _n ) is calculated as the heat generation temperature T _{n−1 of} the motor 23 previously obtained. By adding to the current heat generation temperature of the motor 23 can be estimated.

  Here, in the motor 23 driven by the supply of electric power, the value of the electric resistance of the motor coil increases and the torque decreases as the temperature increases, and conversely, the electric power of the motor coil decreases as the temperature decreases. It has the characteristic that the value of resistance decreases and torque increases. As described above, since the torque of the motor 23 increases or decreases due to the temperature change, there has been a concern that the operation reaction force applied to the knob 21 becomes unstable. In this regard, according to the present embodiment, the microcomputer 31 adjusts the power supplied to the motor 23, that is, the torque of the motor 23 in order to suppress the torque fluctuation due to the temperature change of the motor 23. Therefore, even when the temperature of the motor 23 fluctuates, the stability of the operation reaction force applied to the knob 21 and the operation stability of the operation member are ensured.

  (2) As described above, when power is continuously supplied to the motor 23, such as when the knob 21 is repeated at a short time interval, the heat generation of the motor 23 may progress and lead to an overheated state. There is. In this case, it is not only difficult to secure the required torque, but there is also a concern that the motor 23 may burn out. In this case, since it becomes difficult to apply an operation reaction force to the knob 21, the operability of the knob 21 is significantly reduced. Therefore, in order to suppress such overheating of the motor 23, for example, when the temperature of the motor 23 reaches a predetermined temperature, the supply of electric power to the motor 23 is cut off. It is conceivable to restart the power supply. However, in this case, since the reaction force applied to the knob 21 is lost, the operability of the knob 21 is sacrificed until the temperature of the motor 23 falls below a predetermined temperature. Further, after the supply of electric power to the motor 23 is interrupted, when the temperature of the motor 23 drops below a predetermined temperature and the supply of electric power to the motor 23 is resumed, an operation reaction force to the knob 21 Will be granted suddenly. This is not preferable from the viewpoint of the operational stability of the knob 21.

  In this regard, according to the present embodiment, when it is determined that the estimated temperature of the motor 23 has reached a predetermined temperature determination threshold, the power supplied to the motor 23 is more than the normal power that should be supplied. Reduce. Thereby, overheating of the motor 23 can be suppressed. Unlike the case where the supply of power to the motor 23 is cut off as described above, the supply of the operation reaction force to the knob 21 is continued because the supply of power to the motor 23 is not cut off. For this reason, even when the temperature of the motor 23 reaches a predetermined temperature determination threshold, the operation stability of the knob 21 can be ensured. Further, even when the temperature of the motor 23 falls below a predetermined temperature determination threshold value and the power supplied to the motor 23 is returned to the normal power, the difference in the operation reaction force applied to the knob 21 before and after that. Therefore, the operation stability of the knob 21 is ensured. As described above, the performance of the motor 23, that is, the torque reduction of the motor 23 can be minimized while suppressing the overheating of the motor 23. The performance of the reaction force application type input device 12 is also ensured.

  (3) The microcomputer 31 uses a variable including the current heat generation amount of the motor 23 calculated based on the power supplied to the motor 23 as an argument, and includes the ambient temperature of the motor 23, the same heat capacity, and the same heat radiation resistance. The amount of change in the heat generation temperature of the motor 23 is obtained using a function composed of constants. That is, the temperature change amount of the motor 23 is obtained based on the above-described equation (D).

  By using such a function, the temperature change amount of the motor 23 can be easily obtained based on the power supplied to the motor 23 that can be easily grasped by the microcomputer 31 itself.

(4) When the temperature sensor 41 for detecting the ambient temperature (ambient temperature T ₀ ) of the motor 23 is provided, the motor 23 is used according to the above-described formula (D) using the ambient temperature of the motor 23 at that time. 23 can be obtained. For this reason, the temperature estimation accuracy of the motor 23 by the microcomputer 31 is increased.

  Further, for example, when the temperature sensor constituting the auto air conditioner system is shared as the temperature sensor 41, the configuration is not complicated unlike the case where a dedicated temperature sensor is separately provided. . Further, wiring for connecting the dedicated temperature sensor and the microcomputer 31 is not necessary. In recent years, various types of sensor information can be easily acquired through an in-vehicle network with the digitization of vehicles.

  (5) A current sensor 35 for detecting a current value supplied to the motor 23 and a voltage sensor 34 for detecting a voltage value applied to the motor 23 are provided. The microcomputer 31 calculates the power supplied to the motor 23 by taking into account both the current value detected through the current sensor 35 and the voltage value detected through the voltage sensor 34.

  Thus, the calculation accuracy of the power supplied to the motor 23 can be improved by using the actually measured current value and voltage value. Further, when calculating the power supplied to the motor 23, it is possible to suppress changes in the value of the internal resistance due to the temperature rise of the motor 23 and the influence of the electromotive force when the motor 23 rotates.

  (6) As described above, by adjusting the power supplied to the motor 23 by the microcomputer 31, the operation stability of the knob 21 is ensured while the overheating of the motor 23 is suppressed. Here, as a method of suppressing overheating of the motor 23, it is conceivable to provide the motor 23 with some heat dissipation structure such as a heat sink. However, in this case, there is a concern about an increase in the size of the input device 12 including the motor 23. In particular, in a vehicle, there is a concern that it is difficult to secure an installation space for the input device 12 when various on-board devices are required to be downsized. That is, there is a possibility that the degree of freedom of installation of the input device 12 is significantly limited. In this respect, in the present embodiment, since the overheating of the motor 23 can be suppressed by adjusting the power supplied to the motor 23 by the microcomputer 31, the input device differs from the case where any of the above-described heat dissipation structure is provided in the motor 23. An increase in size of 12 physiques can be avoided.

<Other embodiments>
In addition, you may implement this Embodiment as follows.
In this embodiment, the unit time supplied to the motor 23 using the voltage V applied to the motor 23 acquired through the voltage sensor 34 and the current I supplied to the motor 23 acquired through the current sensor 35 Although the winning power P (= heat generation energy) is obtained, the voltage sensor 34 and the current sensor 35 can be omitted. In this case, steps S102 and S103 in the flowchart shown in FIG. 4 are omitted.

  In the input device 12 of the present embodiment, since the motor 23 is used in a state where it hardly rotates, the current value hardly changes if the voltage value is constant. The motor 23 generates a current comparable to the lock current. The lock current refers to a current value when the motor output shaft is constrained when a rated voltage is applied, and is an approximate value to the starting current value. If it is considered that the amount of change in temperature due to voltage change is small, the power supplied to the motor 23 depends only on the duty ratio of the PWM signal. Therefore, in the above-described equation (A), the current I and the voltage V are set as constants, and only the duty ratio D may be calculated as a variable. Even in this case, the electric power P supplied to the motor 23, that is, the heat generation energy Q of the motor 23 can be estimated.

  Further, when the electric power P supplied to the motor 23, that is, the heat generation energy Q of the motor 23 is obtained, only the voltage applied to the motor 23 may be detected by the voltage sensor 34. Even in this case, the accuracy of estimation of the temperature of the motor 23 by the microcomputer 31 is ensured. In this case, the current sensor 35 can be omitted. Further, the process of step S103 in the flowchart shown in FIG. 4 is omitted.

  Conversely, when obtaining the electric power P supplied to the motor 23, that is, the heat generation energy Q of the motor 23, only the current applied to the motor 23 may be detected by the current sensor 35. In this case, the voltage sensor 34 can be omitted. Moreover, the process of step S102 in the flowchart shown in FIG. 4 is omitted.

  As described above, in the input device 12 according to the present embodiment, the motor 23 is used in a state in which it hardly rotates, so that the change in the voltage applied to the motor 23 is small, and the value of the voltage is regarded as constant. Can do. In this case, the power supplied to the motor 23 is proportional to the value of the current I supplied to the motor 23. Therefore, even when the value of the voltage V applied to the motor 23 is a constant and only the value of the current I supplied to the motor 23 is obtained through the current sensor 35, the power supplied to the motor 23 is calculated. The change in the internal resistance value due to the temperature rise of the motor 23 and the influence of the electromotive force when the motor 23 rotates can be suppressed.

  As described above, the internal resistance of the motor 23, that is, the electric resistance value of the motor coil changes depending on the temperature of the coil. For this reason, when calculating the electric power P supplied to the motor 23 by the above formula (A), the electric resistance value of the motor coil is corrected using the estimated temperature as a coefficient, so that the calculation accuracy of the electric power supplied to the motor 23 can be improved. Further enhanced. In this case, the above-described equation (A) is expressed as the following equation (G).

P = Q = V × I · D = V · (V / Rx) · D (G)
Here, Q is the heat generation energy of the motor 23, V is the voltage applied to the motor 23, Rx is the internal resistance of the motor 23, that is, the electric resistance value of the motor coil, and D is the duty ratio of the PWM signal.

In this case, the internal resistance Rx of the motor 23 is expressed by the following equation (H) as a function of the estimated temperature T _n of the motor 23.
Rx = f (T _n ) (H)
The function represented by the equation (H) is determined by the material and winding method of the motor coil.

  The input device 12 according to the present embodiment includes the single motor 23 so as to apply a predetermined operation reaction force to the rotation operation of the knob 21. For example, the input device 12 can be operated in two directions orthogonal to each other. The present invention can also be applied to a joystick having a provided lever. More specifically, as shown in FIG. 5, the joystick 51 includes an upper movable arm 52 and a lower movable arm 53 that are accommodated in a case (not shown). The upper movable arm 52 and the lower movable arm 53 are formed by curving a strip-shaped plate member having a predetermined width in a semicircular shape, and are disposed so as to be orthogonal to each other. The upper movable arm 52 and the lower movable arm 53 are formed with elongated holes 54 and 55 extending in the axial direction thereof, and a lever 56 is inserted at a position where the elongated holes 54 and 55 intersect. . A grip 57 that is gripped by the user is provided at the tip of the lever 56.

  Two shaft portions 52a and 52b extend to opposite sides at both ends of the upper movable arm 52, and two shaft portions 53a and 53b extend to opposite sides at both ends of the lower movable arm 53. Is provided. The shaft portions 52a and 52b and the shaft portions 53a and 53b are coaxially arranged. Output shafts 23a and 23a of the motor 23 fixed in the case are fixed to one shaft portions 52a and 53a of the upper movable arm 52 and the lower movable arm 53, respectively. Therefore, as the lever 56 tilts, the upper movable arm 52 and the lower movable arm 53 move in two directions (first and second directions) orthogonal to each other with the shaft portions 52a and 52b and the shaft portions 53a and 53b as fulcrums. Swing. At this time, a predetermined operation reaction force is applied to the lever 56 through the driving of the two motors 23, for example, at a generation interval corresponding to the screen 11a. Even when the input device 12 of the present embodiment is applied to the joystick 51 as described above, it is possible to suppress the deterioration in performance due to the heat generation of the motor while achieving both the suppression of the enlargement and the securing of the operability of the lever. it can. In addition, although illustration is abbreviate | omitted in FIG. 5, the rotation angle sensor 24 is provided in the shaft parts 52a and 53a to which the output shafts 23a and 23a of the motor 23 or these output shafts 23a and 23a are connected, respectively.

  -As the actuator, in addition to the motor, a linear motor and a solenoid can be employed. These linear motors, solenoids, and the like have the same problems as the motor 23 because they are actuators that are driven by the supply of electric power, like the motor 23 described above. And the said subject is eliminated by adjusting supply electric power based on estimated temperature, such as a linear motor and a solenoid, similarly to this Embodiment.

In the present embodiment, the configuration in which the output shaft 23a of the motor 23 is directly connected to the knob 21 is adopted, but the output shaft 23a may be connected via a gear mechanism, for example.
In the present embodiment, a plurality of types of auxiliary devices mounted on the vehicle are operated by the single input device 12, but a plurality of input devices 12 are provided corresponding to each auxiliary device. It is also possible to do.

  A predetermined value is applied to a by-wire type shift device in which a shift lever for performing a shift operation of the automatic transmission and the automatic transmission are mechanically separated, or a by-wire type steering device in which a steering wheel and a steering mechanism are mechanically separated. It is also possible to apply the input device 12 of the present embodiment in order to apply the operational reaction force. When the input device 12 is applied to the shift device and the steering device, since the electric power is always supplied to the motor 23 while the vehicle is traveling, the motor 23 is likely to be overheated. In this regard, according to the present embodiment, as described above, the temperature of the motor 23 is estimated, and the electric power supplied to the motor 23 is adjusted based on the estimated temperature, thereby suppressing overheating of the motor 23. I am doing so. Further, when the temperature of the motor 23 reaches a predetermined temperature determination threshold, the supply of power to the motor 23 is not cut off, but the supply power is reduced. For this reason, during operation of the vehicle, the operation reaction force applied to the shift lever or the steering wheel is not necessarily suddenly applied. Therefore, even when the temperature of the motor 23 reaches a predetermined temperature determination threshold, the operation stability of the shift lever or the steering wheel can be ensured. In addition, even when the temperature of the motor 23 falls below the above-described temperature determination threshold, unlike the case where the operation reaction force is not applied at all and the normal application state is returned, the change in the applied operation reaction force is small. Operation stability of the shift lever or the steering wheel is ensured.

The perspective view of the driver's seat which shows the arrangement | positioning aspect of the input device in this Embodiment. The perspective view which shows schematic structure of an input device similarly. The block diagram which similarly shows the electric constitution of an input device. The flowchart which similarly shows the control procedure of the motor which comprises an input device. The schematic perspective view of the joystick in other embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 ... Display (electric equipment), 12 ... Input device, 21 ... Knob (operation member), 23 ... Motor (actuator), 24 ... Rotation angle sensor (operation amount detection means), 31 ... Microcomputer (control means), 35 ... Current sensor (current detection means), 34 ... Voltage sensor (voltage detection means), 41 ... Temperature sensor (temperature detection means), C ... Heat capacity, P ... Power, R ... Heat radiation resistance, ΔT, ΔTn ... Temperature change, Tn , Tn-1 ... temperature.

Claims (5)

The operation amount of the operation member operated by the user is detected through the operation amount detection means, and the power supplied to the actuator is controlled according to the operation amount so as to apply a predetermined operation reaction force to the operation member. In the reaction force imparting type input device comprising a control means for outputting an operation signal corresponding to the operation amount of the operation member to the electric device that is the input operation target of
The control means obtains the amount of change in the heat generation temperature of the actuator based on the power supplied to the actuator at a predetermined calculation cycle, and adds the amount of change in the heat generation temperature obtained this time to the heat generation temperature of the actuator obtained last time. By calculating the current heat generation temperature of the actuator by adjusting the power supplied to the actuator based on the determined heat generation temperature, the operation reaction force applied to the operation member accompanying the temperature change of the actuator A reaction force imparting input device that suppresses fluctuations. The reaction force imparting type input device according to claim 1,
The control means determines whether the heat generation temperature of the actuator has reached a temperature determination threshold value determined to suppress overheating of the actuator, and determines that the temperature of the actuator has reached the temperature determination threshold value. A reaction force imparting type input device that reduces the power supplied to the actuator below the normal power that should be supplied. In the reaction force imparting type input device according to claim 1 or 2,
The control means uses a variable including the current heat generation amount of the actuator calculated based on the power supplied to the actuator as an argument, and the ambient temperature of the actuator, the heat capacity of the actuator, and the heat dissipation in the atmosphere of the actuator. A reaction force imparting type input device that obtains the amount of change in the heat generation temperature of the actuator using a function comprising a constant including resistance. Temperature detecting means for detecting the ambient temperature of the actuator,
The control means takes as an argument a variable including the current heat generation amount of the actuator calculated based on the power supplied to the actuator and the ambient temperature of the actuator detected through the temperature detection means, and the heat capacity of the actuator 3. The reaction force applying input device according to claim 1, wherein a change amount of the heat generation temperature of the actuator is obtained using a function including a constant including a heat radiation resistance in the atmosphere of the actuator. Comprising at least one of current detection means for detecting a current value supplied to the actuator and voltage detection means for detecting a voltage value applied to the actuator;
5. The control unit according to claim 1, wherein the control unit obtains power supplied to the actuator by taking into account at least one of a current value detected through the current detection unit and a voltage value detected through the voltage detection unit. The reaction force imparting type input device according to any one of the above.

Images