JP2002272179A - Actuator control apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stably control feedback by reading a drive current that varies, in response to a pulsive command signal with an appropriate timing. SOLUTION: An MPU 19 outputs a pulsive command signal VP by a PWM means to increase or decrease a drive current Ir, that is supplied from a motor drive circuit 10 to an electric motor 4, and at the same time, reads a current detection signal IS from a resistor 17 to control the feedback of the drive current Ir. Also, the MPU 19 reads the current detection signal IS at the position of a rising edge E1 of a reference signal S, that is outputted from a reference signal generation section 21 when the command signal VP is outputted; and at the same time performs setting, so that the position of the rising edge E1 becomes nearly the center position of a pulse width WP of the command signal VP, thus stably detecting the drive current Ir at constant timing, even when the pulse width WP changes.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an actuator control device suitably used for feedback control of, for example, an output torque of an electric motor, an opening of a solenoid valve, and the like by a PWM (pulse width modulation) signal.

[0002]

2. Description of the Related Art In general, an actuator control device is used to control various actuators such as an electric motor and a solenoid valve. For example, in an electric power steering device mounted on a vehicle such as an automobile, an actuator control device is used. It constitutes a motor control device for controlling the output torque of the electric motor.

[0003] A motor control device according to this type of prior art receives an electric motor as an actuator, and receives a pulse-like command signal to drive the electric motor, and supplies a drive current corresponding to the command signal to the electric motor. A motor drive circuit, a current detector that detects a drive current supplied to the electric motor by the motor drive circuit, and reads a current detection signal output from the current detector to calculate a pulse width of the command signal. It is composed of an arithmetic processing unit such as a microprocessor that outputs a command signal to a motor drive circuit (for example, Japanese Patent Application Laid-Open No. 8-99645).

[0004] The arithmetic processing unit operates using a torque signal input from a torque sensor or the like and a current detection signal output from a current detector when the steering shaft of the vehicle is operated by a driver or the like. A command signal corresponding to the steering force of the user is calculated, and this command signal is output to the motor drive circuit. Thereby, the motor drive circuit supplies a drive current from the power supply side such as a battery to the electric motor, and the electric motor
The rotational torque (auxiliary steering force) according to the steering force of the driver is added to the steering shaft of the vehicle.

In this case, the arithmetic processing unit calculates a target value of the drive current to be supplied from the motor drive circuit to the electric motor in accordance with the torque signal and the like, and in accordance with the target value, the PWM means has a predetermined pulse width ( A voltage signal having a duty ratio is generated, and this voltage signal is output to the motor drive circuit as a command signal. Thus, a drive current corresponding to the pulse width of the command signal is supplied to the electric motor.

Here, the relationship between the command signal and the drive current will be described with reference to, for example, FIG.
a is output as a pulse-like voltage signal, and has a pulse width Wa that is variable with respect to the cycle Ta. The drive current Ia gradually increases when the pulse of the command signal Va is turned on, and gradually decreases when the pulse is turned off. As a result, the drive current Ia changes with a saw-tooth waveform corresponding to the pulse width Wa of the command signal Va, and the temporal average value is increased or decreased according to the pulse width Wa of the command signal Va. Things.

On the other hand, the current detector detects an actual current supplied from the motor drive circuit to the electric motor, and outputs a current detection signal corresponding to the current to the arithmetic processing unit. Then, the arithmetic processing unit reads the current detection signal by A / D conversion, reads the current detection signal, and corrects the command signal using the current detection signal so that the actual magnitude of the drive current matches the target value of the current. Perform feedback control.

In this case, in the conventional processing device, when outputting the pulse of the command signal, for example, as shown in FIG.
A configuration in which a current detection signal from a current detector is read at a timing corresponding to a rising edge Ea or a falling edge Eb of a pulse of a command signal Va shown therein, and the pulse width Wa of the command signal Va is corrected using the read value. And

[0009]

In the above-mentioned prior art, the drive current is read by reading the current detection signal from the current detector at a timing corresponding to the rising edge or the falling edge of the command signal pulse. It is configured to perform feedback control.

However, as shown in FIG. 8, the drive current Ia gradually increases from the rising edge Ea of the pulse of the command signal Va to the falling edge Eb. Therefore, for example, when the read timing of the current detection signal (drive current) is set to the rising edge Ea, for example, the drive current Ia is detected as a value smaller than the actual value at each point a in FIG. There is. In addition, at each point a, since the current value before the drive current Ia increases according to the pulse width Wa is read, there is a problem that the change cannot be detected quickly.

On the other hand, when the read timing of the drive current Ia is set to the falling edge Eb, the command signal Va
If the pulse width Wa of each pulse greatly changes, for example, the current reading timing at each point b in FIG. 8 tends to fluctuate with time, and the detection accuracy of the driving current Ia may become unstable. is there.

For this reason, in the prior art, an error may occur between the current detection signal from the current detector and the actual driving current, or the detection accuracy of the driving current may become unstable. There is a problem that it is difficult to perform control stably.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art. It is an object of the present invention to detect a drive current to an actuator at an appropriate timing and to stably perform feedback control of the drive current. An object of the present invention is to provide an actuator control device that can be used.

[0014]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides an actuator and a pulse-like command signal for driving the actuator, the driving current corresponding to the command signal being supplied to the actuator. Current supply means for supplying a current to the actuator, a current detection means for detecting a drive current supplied to the actuator by the current supply means, and a current detection signal output from the current detection means to read a pulse width of the command signal. The present invention is applied to an actuator control device including a command signal output means for outputting the command signal to the current supply means.

A feature of the configuration adopted in the first aspect of the present invention is that the command signal output means reads the current detection signal input from the current detection means at a timing substantially at an intermediate position of the pulse width of the command signal. That is, a configuration is provided in which detection signal reading means is provided.

With this configuration, the current supply means can supply a drive current to the electric motor in response to a pulse-like command signal output from the command signal output means by, for example, PWM, and read the detection signal. The means can read the current detection signal corresponding to the drive current at a timing substantially at the intermediate position of the pulse width of the command signal, and can perform feedback control of the drive current.

According to the second aspect of the present invention, the command signal output means is provided with a reference signal generation means for generating a reference signal at a constant cycle, and the detection signal reading means is provided with a reference signal from the reference signal generation means. Reading start means for starting reading of the current detection signal when a signal is generated, and a time which is shifted from the reference signal by half of the pulse width before or after the pulse width by half of the pulse width to start or stop outputting the pulse of the command signal. And time setting means for setting the time.

Thus, the reading start means can start reading the current detection signal when the reference signal is generated, and can execute this reading operation at a constant time interval according to the cycle of the reference signal. Further, since the time setting means can set the pulse width with the reference signal as an intermediate position of the pulse width, the detection signal reading means can read the current detection signal at the intermediate position of the pulse width, and at this read timing, The drive current can be detected.

According to a third aspect of the present invention, the actuator is an electric motor mounted on a power steering device for assisting a steering operation of the vehicle, and the command signal output means is provided by the electric motor. The configuration is such that the auxiliary steering force applied to the steering shaft of the vehicle is controlled.

Thus, the command signal output means can feedback-control the drive current supplied to the electric motor of the power steering device by using, for example, a means such as PWM, and the auxiliary steering force by the electric motor can be controlled by the driver. It can be adjusted according to the force or the like.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An actuator control device according to an embodiment of the present invention will be described in detail below with reference to the accompanying drawings, taking an example in which the actuator control device is applied to an electric motor of a power steering device.

Reference numeral 1 denotes a steering shaft for steering the vehicle. The steering shaft 1 includes an input shaft 1A that rotates integrally with a steering handle 2 of the vehicle, and an output shaft that is rotationally driven by an electric motor 4 described later. 1B, the output shaft portion 1B
Is connected to steering wheels (not shown) of the vehicle.

A torque sensor 3 is provided between the input shaft 1A and the output shaft 1B.
It detects a steering direction and a steering force when a driver of the vehicle performs a steering operation, and outputs a torque signal Fs to a control unit 5 described later.

Reference numeral 4 denotes a DC electric motor as an actuator serving as a power source of the power steering device.
Is connected to an output shaft portion 1B of the steering shaft 1 via a reduction gear 4A or the like. Then, when the driver performs a steering operation, the electric motor 4 applies a rotational torque (auxiliary steering force) to the output shaft portion 1B by being supplied with power from a motor drive circuit 10 described later, and the steering force of the driver. Is to assist.

Reference numeral 5 denotes a control unit for driving and controlling the electric motor 4. The control unit 5 includes a motor drive circuit 10, a current detecting resistor 17, and an MPU 1
9, a storage unit 20 and the like. The control unit 5 is connected to a power source such as a battery 7 via an ignition switch 6 of the vehicle, and is grounded to a ground 8 composed of a vehicle body or the like. The control unit 5 is connected to a warning lamp 9 which is turned on when, for example, the motor drive circuit 10 is abnormal.

Next, a circuit configuration of the control unit 5 and the like will be described with reference to FIG.

Reference numeral 10 denotes a motor drive circuit which constitutes a current supply means together with the battery 7. The motor drive circuit 10 comprises, for example, an H-bridge circuit or the like.
The first and second FETs 11 connected in series between the
12, and in parallel with the FETs 11 and 12,
The third and fourth FETs 13 and 14 are connected in series between the battery 7 and the ground 8.

The FETs 11 and 13 are connected in parallel to the battery 7 at a point a via a power supply relay 16 and a current detecting resistor 17 to be described later, and the FETs 12 and 14 are connected to the ground 8 at a point b. Connected in parallel. Also, F
The electric motor 4 is connected between a point c between the ETs 11 and 12 and a point d between the FETs 13 and 14. Also, FET
Gate electrodes 11 to 14 are connected to the MPU 19 via a pre-driver 15 including a signal processing circuit and the like.

The motor drive circuit 10 receives a pulse-shaped command signal VP output from the MPU 19, as shown in FIG. 6, which will be described later, and supplies a drive current Ir corresponding to the pulse width WP of the command signal VP to the battery 7. To the electric motor 4.

Reference numeral 16 denotes a power supply relay provided between the battery 7 and the motor drive circuit 10.
It is opened and closed by the PU 19, and connects and disconnects between the battery 7 and the motor drive circuit 10.

17 is a motor drive circuit 10 and a power supply relay 1
6 is a current detecting resistor provided as a current detecting means provided between the MPU 19 and the MPU 19 via an operational amplifier 18.
It is connected to the. And the current detecting resistor 17 is
The magnitude of the drive current Ir actually supplied from the battery 7 to the electric motor 4 is detected as a voltage drop amount, and a current detection signal Is having a voltage value corresponding to the drive current Ir is generated as MP.
Output to U19.

19 is an MPU as a command signal output means
The MPU 19 is composed of, for example, a microprocessor such as a semiconductor IC, and has a time measurement function using a timer t described later and an interrupt that activates an interrupt processing program shown in FIGS. 4 and 5 described below by a predetermined trigger signal. It has a processing function and a PWM output function of outputting a command signal VP by PWM means using registers R1, R2 and the like described later.

The MPU 19 stores an RO program in which various programs shown in FIGS.
A storage unit 20 including M, RAM, and the like, and a reference signal generation unit 21 described later are connected. And the MPU 19
By controlling the drive current Ir to the electric motor 4 using the torque signal Fs and the like input from the torque sensor 3, the electric motor 4 is controlled according to the driver's steering direction, steering force, and the like.
The rotation direction and the rotation torque are changed.

In this case, the MPU 19 calculates a target current Io as a target value of the drive current Ir by using the torque signal Fs and the like as described later, and for example, a pulse-like voltage corresponding to the target current Io by means such as PWM. A signal is generated as a command signal VP, and the command signal VP is output to the FETs 11 to 14 via the pre-driver 15.

The MPU 19 is connected to the current detecting resistor 1.
7 is read at a timing substantially at the intermediate position of the pulse width WP of the command signal VP, and the command signal VP is corrected in accordance with the read content, so that the magnitude of the drive current Ir is set at the target. The feedback control is performed so as to be equal to the current Io.

Reference numeral 21 denotes a reference signal generation unit as reference signal generation means attached to or incorporated in the MPU 19. As shown in FIG. 6, the reference signal generation unit 21 generates a pulse-shaped reference signal S at a predetermined period TS. This reference signal S has a rectangular waveform that repeats ON and OFF every half cycle (TS / 2).

The MPU 19 outputs, for example, the reference signal S
Is detected by detecting the falling edge E2 of the
The command signal VP is output at a period TP substantially equal to the above. At this time, the pulse width WP of the command signal VP has an intermediate position (time) corresponding to the rising edge E1 of the reference signal S as shown in FIG. It is set as follows.

The power steering apparatus according to the present embodiment has the above-described configuration. Next, control processing by the control unit 5 will be described with reference to FIGS.

First, when the ignition switch 6 is closed (ON), the normal control processing shown in FIG. 3 is executed, and the pulse-like reference signal S shown in FIG. Is output to The normal control process is temporarily interrupted every time the rising edge E1 of the reference signal S occurs.
The reference signal rising edge interrupt processing and the A / D conversion end interrupt processing shown in FIG.

During the operation of the MPU 19, the timer t is cleared to zero at the position of each falling edge E2 of the reference signal S while performing the time counting operation as shown in FIG. The operation of increasing from zero to the period TS of the reference signal S during the falling edge E2 is repeated.

Next, the normal control processing will be described.
At the time of execution of this control processing, first, various initial settings and the like are performed in step 1 in FIG. 3 to close the power supply relay 16, and in step 2, the torque signal Fs output from the torque sensor 3 is read.

In step 3, a target value of an auxiliary steering force to be generated by the electric motor 4 is calculated as a target torque Fo in accordance with the torque signal Fs and the driving state of the vehicle. The target value of the drive current Ir supplied to the electric motor 4 for generating the torque Fo is calculated as the target current Io.

Next, at step 5, this processing is set to an interrupt permission state such that the reference signal rising edge interrupt processing is started by the rising edge E1 of the reference signal S shown in FIG. 6, for example. As a result, when the rising edge E1 of the reference signal S is output, the reference signal rising edge interrupt processing and the A / D conversion end interrupt processing are sequentially activated as described later, so that the command signal VP in FIG. Is FET1
1 to 14 and the command signal V
The drive current Ir corresponding to the pulse width WP of P is supplied to the electric motor 4.

At the time of output of the command signal VP, F is determined according to the driver's steering direction detected by the torque signal Fs.
One set of FETs among the ETs 11 and 14 and the FETs 12 and 13 is closed, and another set of FETs is closed.
As a result, the MPU 19 variably sets the direction of the drive current Ir supplied from the motor drive circuit 10 to the electric motor 4, and controls the rotation direction of the electric motor 4 according to the driver's steering direction. Therefore, the command signal VP in FIG.
Power is supplied to the electric motor 4 through ET11 and ET14,
This is an example of a state in which 12, 13 are opened.
Further, in this case, the FET 1 of the FETs 11 and 14
1 is kept in a closed state, and the magnitude of the drive current Ir is controlled by outputting a pulse-like command signal VP to the FET 14.

On the other hand, in the next step 6, it is determined whether or not the drive system such as the electric motor 4, the motor drive circuit 10 and the like is operating normally.
Move to step 7 and open the ignition switch (O
Steps 2 to 7 are repeatedly executed until FF). Then, when the ignition switch is opened, the control process ends in step S8.

If "NO" is determined in step 6, the power supply relay 16 is opened in step 9, for example.
By turning on the warning light 9, the fail-safe processing is executed, and the control processing is ended in step 8.

Next, the reference signal rising edge interrupt processing will be described with reference to FIG. Here, the interrupt processing is set to the interrupt permission state in step 5, and when the rising edge E1 of the reference signal S is detected, the interrupt processing is started with the rising edge E1 as a trigger signal to interrupt other program processing. It is executed in the state where it was done.

In step 11, the current detection signal I output from the current detection resistor 17 as a voltage signal is output.
The reading process (A / D conversion process) of s is started. At this time, the A / D conversion processing of the current detection signal Is is performed as shown in FIGS.
As shown in (1), it is configured to start at a substantially intermediate position of the pulse width WP of the command signal VP for the reason described later.

In step 12, the current detection signal I
This processing is set to the interrupt permission state so that the A / D conversion end interrupt processing described later is started when the A / D conversion processing of s is completed. Further, in step 13, the currently executing reference signal rising edge interrupt processing is executed in step 5.
To set the interrupt prohibition state until it is permitted again, and return to step 14.

As a result, when the A / D conversion processing of the current detection signal Is ends, the A / D conversion end interrupt processing shown in FIG. 5 is started with this end operation as a trigger signal. The / D conversion end interrupt processing will be described.

First, at step 21, the currently executing A / D conversion end interrupt processing is set to the interrupt prohibited state until it is permitted again at step 12, and at step 22, the A / D conversion is stopped at step 11. The drive current Ir actually supplied to the electric motor 4 is calculated using the converted current detection signal Is, the resistance value of the current detection resistor 17, and the like.

Next, at step 23, the actual drive current Ir is compared with the target current Io calculated at step 4, and the target voltage Vo to be output to make the drive current Ir follow the target current Io is calculated. . Then, in step 24,
The pulse width WP when the target voltage Vo is output as a pulse-like command signal VP by the PWM means is calculated.

Next, in step 25, the PWM output registers R1 and R2 provided in the MPU 19 are set to the pulse width W.
Set according to P. Here, the register R1 stores the command signal V
The output start time (timing) of the P pulse is set, and the register R2 is used to set the output stop time of this pulse.

In step 25, a half pulse width (WP / 2) obtained by dividing the pulse width WP of the command signal VP into two equal parts and a timer t stored in the storage unit 20 in advance, as shown in the following equation (1). And setting the output start register R1 to a value smaller than the intermediate value (TS / 2) of the timer t by half a pulse width (WP / 2) using the intermediate value (TS / 2) of
The register R2 on the output stop side is set to a value larger than the intermediate value (TS / 2) by a half pulse width (WP / 2).

[0055]

R1 = (TS / 2)-(WP / 2) R2 = (TS / 2) + (WP / 2)

In this case, the intermediate value of the timer t (TS / 2)
7 has a reference timing substantially coincident with the rising edge E1 of the reference signal S, as shown in FIG. 7, the registers R1 and R2 store a half pulse width (WP / 2) It is set as the time shifted by minutes before and after.

In step 26, when the timer t increases and coincides with the register R1, the pulse output of the command signal VP is started, and the timer t further increases and the register R
When the value matches 2, the pulse output is stopped, so that a command signal VP having a pulse width WP is output.

In the middle position of the pulse width WP,
As described above, the reference signal rising edge interrupt processing and the A / D conversion end interrupt processing are sequentially activated by the rising edge E1 of the reference signal S. Therefore, the command is issued using the current detection signal Is read at this intermediate position. The pulse width WP of the signal VP can be calculated, and the feedback control of the drive current Ir can be performed.

Thus, according to the present embodiment, the MPU
19 is configured to read the current detection signal Is outputted from the current detection resistor 17 at a timing substantially at an intermediate position of the pulse width WP of the command signal VP, When the drive current Ir repeatedly increases and decreases, the current value can always be stably read at a constant timing at the middle position of the pulse width WP, and increases from the rising edge to the falling edge of the command signal pulse. The drive current Ir can be reliably detected as an intermediate current value located between these edges.

Further, the MPU 19 includes the reference signal generator 2
The rising edge E1 of the reference signal S generated from 1 is set as a reference timing, and a time shifted by a half pulse width (WP / 2) before and after this timing is set as an output start time and an output stop time of the command signal pulse. Registers R1, R2
And the reading process of the current detection signal Is is started by the rising edge E1.

As a result, for example, even when the pulse width WP of each pulse of the command signal VP fluctuates greatly, the reference signal S
Each pulse of the command signal VP can be easily generated with the rising edge E1 of the pulse width WP as an intermediate position of the pulse width WP. Further, the drive current Ir can be reliably detected at a constant time interval corresponding to the cycle TS of the reference signal S, and the detection timing can be favorably held at the intermediate position regardless of the fluctuation of the pulse width WP.

As a result, it is possible to reliably prevent the drive current from being detected as a value smaller than the actual value as in the prior art, and to prevent the detection timing of the current from being varied due to the variation in the pulse width of the command signal. Detection sensitivity, detection accuracy, and the like can be stabilized, and feedback control of the drive current Ir can be accurately performed.

Therefore, during operation of the vehicle, the electric motor 4
Thus, the auxiliary steering force applied to the steering shaft 1 can be appropriately adjusted according to the driver's steering force and the like, and the performance and reliability of the power steering device can be improved.

In this embodiment, the reference signal rising edge interrupt processing and the A / D conversion end interrupt processing shown in FIGS. 4 and 5 are specific examples of the detection signal reading means. Indicates a specific example of the reading start means, and step 25 in FIG. 5 indicates a specific example of the time setting means.

In the embodiment, the reference signal rising edge interrupt processing is performed at the position of the rising edge E1 of the reference signal S.
Although the A / D conversion end interrupt processing is performed and the timer t is cleared at the position of the falling edge E2, the present invention is not limited to this. The timer t is cleared at the position of the rising edge E1 and the timer t is cleared. The above-described interrupt processing may be executed at the position of the edge E2.

Further, in the embodiment, the electric motor of the power steering device has been described as an example of the actuator. However, the present invention is not limited to this, and the operation amount is controlled by a pulse-like command signal such as a solenoid valve. It is good also as a structure applied to various actuators controlled.

[0067]

As described above in detail, according to the first aspect of the present invention, the command signal output means outputs the current detection signal output from the current detection means at a timing substantially at the intermediate position of the pulse width of the command signal. When the drive current repeatedly increases and decreases according to ON and OFF of the command signal pulse, the current value is always stably maintained at a constant timing at an intermediate position of the pulse width. The drive current that can be read and increases from the rising edge to the falling edge of the command signal pulse can be reliably detected as an intermediate current value located between these edges. This makes it possible to stabilize the detection sensitivity, detection accuracy, and the like of the drive current, perform the feedback control with high accuracy, and increase the performance and reliability of the actuator control device.

According to the second aspect of the present invention, the command signal output means is provided with a reference signal generating means for generating a reference signal at a constant cycle, and the detection signal reading means is provided when the reference signal is generated. And a time setting means for setting the time shifted by half the pulse width before and after the reference signal as the pulse output start time and the output stop time, respectively. The reading start means can detect the drive current at a constant time interval corresponding to the cycle of the reference signal even if the pulse width of the command signal fluctuates greatly, for example, and reliably prevent the occurrence of variation in the current detection timing. be able to. Then, since the time setting means can set the pulse width with the reference signal as the middle position of the pulse width, the drive current can be stably detected at the middle position of the pulse width regardless of the fluctuation of the pulse width.

According to the third aspect of the present invention, since the actuator is constituted by the electric motor of the power steering device, the command signal output means can be connected to the electric motor of the power steering device using, for example, PWM. The supplied drive current can be stably feedback-controlled, and the auxiliary steering force applied from the electric motor to the steering shaft of the vehicle can be appropriately adjusted according to the driver's steering force and the like, and its performance and reliability are improved. be able to.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a power steering device applied to an embodiment of the present invention.

FIG. 2 is a circuit configuration diagram showing a circuit configuration of a control unit.

FIG. 3 is a flowchart showing control processing of an electric motor by a control unit.

FIG. 4 is a flowchart showing a reference signal rising edge interrupt process;

FIG. 5 is a flowchart showing A / D conversion end interrupt processing;

FIG. 6 is a characteristic diagram showing a relationship between states of a reference signal, a timer, a command signal, and a driving current and reading timing of a current detection signal.

FIG. 7 is a characteristic diagram showing a state in which a pulse of a command signal is output according to the setting of a PWM output register.

FIG. 8 is a characteristic diagram showing a relationship between a command signal and a drive current by a conventional motor control device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Steering axis 2 Handle 3 Torque sensor 4 Electric motor (actuator) 5 Control unit 6 Ignition switch 9 Warning light 10 Motor drive circuit (Current supply means) 11, 12, 13, 14 FET 17 Current detection resistor (Current detection means) ) 19 MPU (command signal output means) 21 reference signal generation section (reference signal generation means)

Claims (3)

[Claims] An actuator; a current supply means for receiving a pulse-like command signal for driving the actuator and supplying a drive current corresponding to the command signal to the actuator; Current detection means for detecting the supplied drive current;
A command signal output unit that reads a current detection signal output from the current detection unit, calculates a pulse width of the command signal, and outputs the command signal to the current supply unit. The actuator control device is characterized in that the means comprises detection signal reading means for reading a current detection signal input from the current detection means at a timing substantially at an intermediate position of a pulse width of the command signal. 2. The method according to claim 1, wherein said command signal output means includes a reference signal generating means for generating a reference signal at a constant cycle, and said detection signal reading means outputs a reference signal when said reference signal generating means generates a reference signal. Reading start means for starting reading of the current detection signal, and time setting means for setting times shifted by half the pulse width before and after the reference signal as the output start time and the output stop time of the pulse of the command signal. The actuator control device according to claim 1, comprising: 3. The actuator is an electric motor mounted on a power steering device for assisting a steering operation of the vehicle, and the command signal output means is applied to a steering shaft of the vehicle by the electric motor. 3. The actuator control device according to claim 1, wherein the control device controls the auxiliary steering force.