JP2010119210A - Control device for use in vehicle switchgear - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To detect a load of a DC motor compatible with various loads. <P>SOLUTION: A control part 1 which drive-controls a motor 3 includes: a motor drive voltage detection circuit 5; an angular acceleration calculation part 8a connected to a motor rotation sensor 6; an estimated load calculation part 8b which calculates an estimated load being an external load of the motor 3 on the basis of a drive voltage, an angular speed and an angular acceleration; and a determination part 8c which determines that something is caught on the basis of the estimated load. Since the angular speed and the voltage are changed when the external load is applied, the external load can be calculated as the estimated load by using an estimated load calculation formula in which coefficients of items are properly defined, and thus whether something is caught or not can quickly and surely be determined. In particular, the estimated load of a soft material caught at a power window can accurately be calculated by including a viscosity coefficient of an internal load of the motor into a rotation speed change item. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a control device used in an opening / closing device for a vehicle.

  In a control device used in a switchgear for a vehicle, the load of the armature that drives the switchgear can be obtained from the terminal voltage of the armature and the current flowing through the armature. For this reason, when a current pickup coil is used or a shunt resistor having a very small resistance is used, the number of parts is increased and the cost is increased.

  In order to solve such a problem, the function of the terminal voltage and the rotational speed is stored in advance in the load characteristic storage means as a mathematical expression or a two-dimensional table, and the load characteristic storage means is based on the terminal voltage and the rotational speed detection value. There is one in which the load is estimated from the contents (for example, see Patent Document 1).

Japanese Patent Publication No. 8-13197 (page 3, FIG. 1)

  However, in the case of using the load characteristic storage means, it is preferable to acquire the data by testing the load characteristic stored in advance in a state in which it is used. There is a problem that it is necessary to increase the number of points, and the cost is increased due to these operations. For example, if it is intended to be applied to an automobile window pinching prevention device, the object to be pinched has various rigidity, and measurement corresponding to everything is extremely difficult.

In order to solve such problems and realize a control device used in a vehicle switchgear that can cope with various loads, in the present invention, a DC motor capable of forward and reverse rotation and a work switch are provided. An auto control circuit that outputs a control signal in response to an open / close operation signal that is generated; a motor drive control circuit that generates a drive signal for driving and controlling the DC motor in response to a control signal generated by the auto control circuit; A rotation sensor that outputs a pulse signal in conjunction with the rotation of the DC motor, an angular velocity calculation circuit that calculates the rotation speed of the DC motor as an angular velocity signal based on the pulse signal from the rotation sensor, and an angular velocity calculation circuit An angular acceleration calculation unit that calculates an angular acceleration signal of rotation of the DC motor based on an angular velocity signal; a voltage detection circuit that detects a drive voltage of the DC motor; An estimated load calculating unit that calculates an estimated load from an angular velocity signal of the angular velocity calculating circuit, an angular acceleration signal of the angular acceleration calculating unit, and a driving voltage of the voltage detecting circuit; and an estimated load calculated by the estimated load calculating unit A control unit used in a vehicle opening / closing device having a determination unit that compares a predetermined threshold value and stops a drive signal generated by the motor drive control circuit when an estimated load is larger than a predetermined threshold value The motor drive control circuit is either a motor drive control circuit that drives and controls the DC motor by a DC voltage drive signal, or a motor drive control circuit that drives and controls the DC motor by a PWM drive signal. The estimated load calculation unit calculates the viscosity coefficient (Bm) to the angular velocity difference (ω0−ω) obtained by subtracting the angular velocity (ω) from the angular velocity steady value (ω0) obtained in advance. An angular velocity difference term that is multiplied by a coefficient (Bm + a), a voltage difference term (V−V0) obtained by subtracting a voltage signal (V0) obtained in advance from the voltage signal (V), and an angular acceleration (dω). Based on the angular acceleration term multiplied by the constant Jm × g, the estimated torque T is calculated by the following equation to obtain the estimated load.
T = (Bm + a) (ω0−ω) + b (V−V0) −Jm · g · dω
(A and b are predetermined constants, g is a predetermined gain, Jm is a predetermined moment of inertia)

  There are constant voltage control and PWM control for driving a driven body by a DC motor with the external load being in a no-load state, but there is an external load on the driven body for steady-state driving in such control. When is added, the rotational speed of the motor decreases. In constant voltage control, the motor drive voltage further decreases, and in PWM control, control for correcting the reduced motor rotation speed to the target speed works. Therefore, the duty ratio corresponding to the motor drive voltage is To increase. As described above, when an external load is applied, the rotational speed change term and the voltage change term in the term for calculating the estimated load change, so by appropriately determining the coefficients of those terms, The load can be calculated as an estimated load. By comparing the estimated load calculated in this way with a threshold value, for example, pinching in a power window device for an automobile can be detected by the load, so that quick and reliable pinching determination can be performed.

  In particular, a coefficient including the viscosity coefficient of the internal load of the motor may be used as the coefficient of the rotational speed term. Since there is viscous damping in the object to be pinched in the power window device, the load at the time of pinching cannot be accurately calculated with a simple speed reduction, but the rotational speed change term should be calculated in consideration of the effect of viscous damping. Thus, a highly accurate estimated load can be calculated.

  As described above, according to the present invention, when an external load is applied, the rotational speed change term and the voltage change term in the term for calculating the estimated load change, so that the coefficients of these terms are appropriately determined. The external load can be calculated as an estimated load using the estimated load calculation formula, and by comparing the estimated load with a threshold value, for example, pinching in a power window device for an automobile can be detected by the load. Immediate and reliable pinching determination can be performed. In particular, because there are soft objects in the power window device, the load at the time of pinching cannot be accurately calculated with a simple speed reduction, but the viscosity coefficient of the internal load of the motor is included in the rotational speed change term. Thus, the estimated load when the soft object is caught can be calculated with high accuracy.

  Hereinafter, embodiments of the present invention will be described in detail based on specific examples shown in the accompanying drawings.

  FIG. 1 is a block diagram showing an example in which a control device used in a vehicle opening / closing device according to the present invention is applied to an automotive power window device. As shown in the drawing, the control unit 1 outputs an automatic or manual opening / closing control signal to the control unit 1 according to each opening / closing operation signal of the automatic operation switch 2a and the manual operation switch 2b provided in the driver's seat or the like. And a drive circuit 4 as a motor drive control circuit for forward / reverse drive control of the DC motor 3 according to the open / close control signal, a voltage detection circuit 5 for detecting the drive voltage of the motor 3, and the rotation of the motor 3. An angular speed calculation circuit 7 that calculates the rotational speed of the motor 3 as an angular speed based on the interval of the pulse signal from the rotation sensor 6 as the interlocking rotational speed detection means, and a CPU 8 that performs the main control of the control unit 1 are provided. Yes.

  The CPU 8 calculates an angular acceleration calculation unit 8a that calculates angular acceleration based on the angular velocity signal from the angular velocity calculation circuit 7, and calculates an estimated load that is an external load of the motor 3 based on the drive voltage, angular velocity, and angular acceleration. An estimated load calculation unit 8b serving as an estimated load calculation unit and a determination unit 8c that determines pinching based on the estimated load are provided. The angular acceleration calculation unit 8a, the estimated load calculation unit 8b, and the determination unit 8c may be performed by program processing in the CPU 8.

  Then, the motor 3 rotates forward or backward in response to a drive signal from the drive circuit 4, and a window 9 as a driven body connected to the motor 3 via a link or a wire is opened and closed. The auto control circuit 1a outputs a continuous open / close control signal when the open / close signal of the auto operation switch 2a is input, and the open / close signal of the manual operation switch 2b is input. Outputs an open / close control signal only during operation.

  Next, an example of pinching determination control by the power window device configured as described above will be described below with reference to the flowchart of FIG. 2 is performed by program processing in the CPU 8 for each pulse count of the rotation sensor 6, for example.

  First, in step ST1, it is determined whether or not the pulse signal output from the rotation sensor 6 has been switched. If it is determined that the pulse signal has not been switched, step ST1 is repeated. If it is determined that the pulse signal has been switched, the process proceeds to step ST2. In step ST2, the terminal voltage V of the motor 3 is detected by the voltage detection circuit 5 and A / D converted, and the process proceeds to step ST3.

  In step ST3, the angular velocity calculation circuit 7 calculates the period t based on the interval between the pulse signals supplied from the rotation sensor 6, and calculates the angular velocity ω (= 2π / t) as the angular velocity signal from the value. Output. In this calculation, the pulse interval is converted to time and linear interpolation is performed by angular velocity sampling rate conversion. As the angular velocity sampling rate conversion, for example, the angular velocity ω of the motor 3 obtained as described above is calculated for each pulse signal input, a change in the angular velocity ω is estimated from the previous value and the current value, and based on the estimated change. Then, the conversion from the pulse interval to the time may be performed by calculating the estimated angular velocity at every sampling timing until the next pulse signal input. In the next step ST4, the angular acceleration calculation unit 8a calculates an angular acceleration dω as an angular acceleration signal based on the angular velocity ω calculated by the angular velocity calculation circuit 7 in step ST3, and outputs it. Then, the process proceeds to step ST5.

In step ST5, the estimated load calculation unit 8b calculates an estimated torque T corresponding to the estimated load P that is an external load of the motor 3 based on the terminal voltage V (average voltage), the angular velocity ω, and the angular acceleration dω. Ask for.
T = (Bm + a) (ω0−ω) + b (V−V0) −Jm · g · dω (1)
Here, Bm is the viscosity coefficient of the motor internal load, a is a constant, (ω0−ω) is the angular velocity difference (ω0 is the steady angular velocity value when no external load is applied), b is the constant, and (V−V0) is the voltage difference ( V0 is a steady voltage value applied to the motor 3 when there is no external load), Jm is the moment of inertia of the device including the motor 3 (window opening and closing device in the illustrated example), and g is the adjustment gain. In the above equation (1), (Bm + a) (ω0−ω) is an angular velocity difference calculation term, b (V−V0) is a voltage difference calculation term, and Jm · g · dω is an angular acceleration calculation term.

  In the next step ST6, it is determined whether or not the estimated load P obtained from the estimated torque T obtained in step ST5 is greater than or equal to a load threshold PL as a predetermined threshold, and the estimated load P is greater than or equal to the load threshold PL. In this case, the process proceeds to step ST7, and when the estimated load P is less than the load threshold PL, the process proceeds to step ST8. In step ST7, 1 is added to the number of detection state continuations in order to count up the number of times the detection state is continued. In step ST8, the detection state continuation count is cleared to 0, and the process returns to step ST1.

  In step ST9 following step ST7, it is determined whether or not the number of detection state continuations is equal to or greater than a predetermined determination number. By setting the number of times of determination to 2 or more, it is possible to determine a case where the estimated load P continues to be equal to or greater than the load threshold PL. When the estimated load P exceeds the momentary load threshold PL due to sudden noise or the like, the detection state continuation count is cleared in step ST8, so that erroneous determination due to an instantaneous increase in the estimated load P is prevented. Can do.

  If it is determined in step ST9 that the detection state continuation count is not greater than or equal to the determination count, the process returns to step ST1. If it is determined that the number of detection state continuation times is equal to or greater than the determination number, the process proceeds to step ST10 where the pinching determination is confirmed. In addition, when the pinching determination is confirmed, another processing routine proceeds, and for example, processing for stopping the motor 3 is performed. After the object to be pinched is removed, the process can proceed from step ST6 to step ST8, so that the normal opening / closing control state can be returned.

  Next, calculation of the above equation (1) will be described below. First, FIG. 3 shows a motor model for deriving equation (1). In the figure, when the motor 3 rotates by an angle θ in the direction of arrow A, the friction torque of Bm · ω and the load torque TL are acting in opposite directions with respect to the motor torque Tm at that time. Yes. Jm is the moment of inertia described above.

First, the following equation is derived from the motor model.
ω = ∫ {(Tm−TL−Bm · ω) / Jm} dt (2)
The motor torque Tm in the equation (2) can be expressed by the following equation.
Tm = Kt · i (3)
Here, i is a current flowing through the motor, and Kt is a torque constant when torque is converted from the current i.

Further, the load torque TL in the equation (2) can be expressed by the following equation.
TL = k · θ · R + TL0 (4)
Here, k is the spring constant of the sandwiched object, R is the radius of the rotating body, and TL0 is the initial load torque (rated load).

When the above equation (2) is differentiated by t and arranged,
Tm = Jm · dω + Bm · ω + TL (5)
When the above equations (3) and (4) are substituted into equation (5),
Kt.i = Jm.d.omega. + Bm..omega. + K..theta..R + TL0 (6)
It becomes. Here, when θ = 0, by setting dω to 0, the equation (6) becomes
Kt · i ₀ = Bm · ω ₀ + TL0
Because
_{TL0 = Kt · i 0 -Bm ·} ω 0 ... (7)
It becomes.

Substituting the above equation (7) into equation (6),
Kt · i = Jm · dω + Bm · ω + k · θ · R + Kt · i 0 -Bm · ω 0 ... (8)
It becomes. In this equation (8), the estimated torque T corresponding to the estimated load P is k · θ · R.
k · θ · R = Bm (ω ₀ −ω) + Kt (i−i ₀ ) −Jm · dω (9)
Are arranged. If Kt (i−i ₀ ) in equation (9) is replaced with motor torque in equation (3),
k · θ · R = Bm (ω ₀ −ω) + (Tm−Tm ₀ ) −Jm · dω (10)
It becomes.

Here, (Tm−Tm ₀ ) can be decomposed into a voltage and a rotational speed and expressed by the following equation.
Tm = −a · ω + b · V + c (11)
This equation (11) is obtained from the motor characteristics shown in FIG. FIG. 4 is a diagram showing the relationship between the rotational speed ω and the torque Tm by the difference in the voltage V (V0 <V1 <V2). This motor characteristic can be converted into a function or a map and stored in the ROM as a constant. In a device using the same type of motor, the same data may be used as the characteristics of the motor, and it is not necessary to take data for each device.

And when substituting equation (11) into equation (10),
k · θ · R = (Bm + a) (ω ₀ −ω) + b (V−V 0) −Jm · dω (12)
It becomes. K · θ · R on the left side of the equation (12) is the estimated torque T corresponding to the estimated load P in the equation (1). When the gain g of the angular acceleration calculation term in equation (1) is 1, equation (12) is obtained. In practice, a gain adjuster can be provided to enable high-accuracy adjustment according to the apparatus, in which case equation (1) is used.

In addition, a coefficient (Bm + a) including a viscosity coefficient Bm of the motor internal load is used as a speed change term (ω ₀ −ω) in an equation for calculating the estimated torque T (estimated load P). This is effective when the external load for each device can be specified to some extent. As in the above example, a soft object is considered as the object to be sandwiched in the automotive power window device, and the viscous friction coefficient Bm is used, so that the estimated load at the time of sandwiching can be made highly accurate. In the case of other devices, it is only necessary to set a viscous friction coefficient of an external load that can be considered according to each device, and it is possible to calculate a highly accurate estimated load according to the use state.

In the above example, the direct-current voltage control in which the direct-current voltage is supplied from the power source is shown. However, according to the present invention, the present invention can be applied to other motor drive control. One example is PWM control. In the above equation (1), terms that can be seen as changes when PWM control is performed are (ω ₀ −ω) that is a variable of a term that represents a change in speed (angular velocity) and a variable that is a term that represents a change in voltage. (V-V0).

  First, when viewed from a speed change, the speed change in the constant voltage control changes as shown in FIG. As shown in the figure, before the sandwiching, the external load is in a no-load state, so that the transition is made at a constant speed, and the speed is decreased from the start of the sandwiching. For example, when pinching detection is performed at a speed, the pinching detection level ωL is set as shown in the figure.

  On the other hand, the speed change in the PWM control changes as shown in FIG. As shown in the figure, the speed is once reduced by the start of pinching, but when the duty ratio is controlled to be increased by PWM control, the speed reduction is suppressed. In this PWM control, when the same pinching detection level ωL as in the constant voltage control is set, it is as shown in the figure. Thus, when the pinching is viewed as a speed change, the speed change amount is larger in the constant voltage control than in the PWM control.

  Next, when viewed in terms of voltage (motor drive voltage) change, the voltage change in constant voltage control changes as shown in FIG. In the same manner as in FIG. 5A, before the pinching, since the external load is in a no-load state, the voltage changes at a constant voltage. When pinching occurs, a load is applied to the motor 3 so that a counter electromotive current flows toward the power source due to the counter electromotive force. Therefore, as the pinching state progresses, the terminal voltage of the motor 3 decreases as shown in the figure. Get up.

  In PWM control, the motor drive voltage can be obtained by multiplying the power supply voltage by the duty ratio, and therefore, the voltage corresponding to the voltage can be regarded as the duty ratio. The change in the duty ratio is as shown in FIG. In the figure, it is shown that the duty ratio increases after the start of sandwiching. This is because when the motor rotation speed decreases due to the pinching, the duty ratio is increased to maintain the target speed by PWM control. In this way, when the pinching is viewed as a voltage change, the constant voltage cannot be maintained as the pinching progresses, and the voltage drops because of the pinching, and the voltage is increased in the PWM control.

Thus, the constant voltage control and the PWM control are different in the speed change term (Bm + a) (ω ₀ −ω) and the voltage change term b (V−V 0), but are different in the speed change term. In contrast, the constant voltage control is greatly reduced, while the PWM control is gradually reduced. In the voltage change term, the constant voltage control is reduced, whereas the PWM control is large. To increase.

  In constant voltage control, the speed change term increases greatly with a positive value, and the voltage change term increases slowly with a negative value. In PWM control, the speed change term increases slowly at a positive value, and the voltage change term increases greatly at a positive value. When the influence on the sum of each term is greater in the speed change term than in the voltage change term, the estimated torque T (estimated load P) as the sum of each term does not change, and the vehicle does not depend on the control method. It is possible to establish a control device used for the switchgear for a vehicle. In the present embodiment, an example suitable for a power window device for an automobile has been shown, but the present invention is not limited to this, and other side slide doors for automobiles, back doors, The present invention can also be applied to an opening / closing device such as a trunk lid.

1 is a motor drive control circuit diagram of an automotive power window device to which the present invention is applied. The control flow figure based on this invention. The perspective view which shows a motor model. The figure which shows a motor characteristic. (A) is a figure which shows the angular velocity change in constant voltage control, (b) is a figure which shows the angular velocity change in PWM control. (A) is a figure which shows the voltage change in constant voltage control, (b) is a figure which shows the voltage change in PWM control.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Control part 2a Auto operation switch, 2b Manual operation switch 3 Motor 4 Drive circuit 5 Voltage detection circuit 6 Rotation sensor 7 Angular velocity calculation circuit 8 CPU
8a angular acceleration calculation unit, 8b estimated load calculation unit, 8c determination unit 9 window

Claims (1)

DC motor that can rotate forward and reverse,
An auto control circuit that outputs a control signal in response to an opening / closing operation signal generated by the operation switch;
A motor drive control circuit for generating a drive signal for driving and controlling the DC motor in response to a control signal generated by the auto control circuit;
A rotation sensor that outputs a pulse signal in conjunction with the rotation of the DC motor;
An angular velocity calculation circuit for calculating a rotational velocity of the DC motor as an angular velocity signal based on a pulse signal from the rotation sensor;
An angular acceleration calculation unit that calculates an angular acceleration signal of rotation of the DC motor based on an angular velocity signal from the angular velocity calculation circuit;
A voltage detection circuit for detecting a drive voltage of the DC motor;
An estimated load calculating unit that calculates an estimated load from an angular velocity signal of the angular velocity calculating circuit, an angular acceleration signal of the angular acceleration calculating unit, and a driving voltage of the voltage detecting circuit;
A determination unit that compares the estimated load calculated by the estimated load calculation unit with a predetermined threshold value, and stops a drive signal generated by the motor drive control circuit when the estimated load is greater than a predetermined threshold value;
A control device used in a vehicle opening and closing device having
The motor drive control circuit is either a motor drive control circuit for driving and controlling the DC motor by a DC voltage drive signal, or a motor drive control circuit for driving and controlling the DC motor by a PWM drive signal,
The estimated load calculation unit
An angular velocity difference term which is obtained by multiplying an angular velocity difference (ω0−ω) obtained by subtracting the angular velocity (ω) from a previously obtained angular velocity steady value (ω0) by a coefficient (Bm + a) having a viscosity coefficient (Bm);
A voltage difference term (V-V0) obtained by subtracting a voltage signal (V0) obtained in advance from the voltage signal (V);
An opening / closing device for a vehicle characterized in that an estimated load is obtained by calculating an estimated torque T according to the following equation based on an angular acceleration term obtained by multiplying an angular acceleration (dω) by a predetermined constant Jm × g. Control device used.
T = (Bm + a) (ω0−ω) + b (V−V0) −Jm · g · dω
(A and b are predetermined constants, g is a predetermined gain, Jm is a predetermined moment of inertia)

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