JP2861179B2 - Motor control drive - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor control driving device suitable for controlling and driving a motor for driving a steering handle, for example.

[Conventional technology]

FIG. 7 shows a configuration of an example of a conventional motor control drive device that controls and drives a motor that drives a steering handle. In this figure, a motor 102 is a motor that drives a steering handle. The torque sensor 104 is
When the steering wheel is turned left or right, the torque is detected, and a torque detection signal is supplied to a control circuit 108 including a microprocessor (MPU) via a sensor amplifier 106. When receiving the torque detection signal, the control circuit 108 turns on the power relay 110 and
A voltage is applied from 12 to the servo amplifier 114. Servo amplifier 1
The 14 supplies a current corresponding to the detected torque to the motor 102 to drive the motor 102.

On the other hand, the actual current value of the motor 102 is detected, and the detected current value is fed back to the servo amplifier 114. The servo amplifier 114 supplies the motor 102 with a current equal to the command value (detected torque value) from the control circuit 108. To compensate for the voltage fluctuation of the battery 112.

The motor temperature detector 116 detects the temperature of the motor 102,
The temperature detection signal is sent to the control circuit 1 via the interface 118.
Supply to 08. When the temperature indicated by the temperature detection signal exceeds a predetermined reference value, control circuit 108 determines that there is some abnormality and stops driving motor 102.

[Problems to be solved by the invention]

The conventional motor control and driving device shown in FIG. 7 requires a system for detecting the actual current value of the motor and feeding it back to the servo amplifier 114 in order to compensate for fluctuations in the power supply voltage of the motor. It is.

The present invention provides a motor control drive device that can generate a required torque from a motor without requiring a servo amplifier having a feedback loop, even if the temperature and power supply voltage of the motor fluctuate. Aim.

[Means for solving the problem]

A motor control drive device according to the present invention includes a torque detector that detects a torque required for a motor, a temperature detector that detects a temperature of the motor, a voltage detector that detects a power supply voltage of the motor, a motor torque, and a motor. A storage device that stores a motor current value required to generate the torque at the motor temperature and the motor power supply voltage, using a value corresponding to each of the temperature and the motor power supply voltage as an address, and the torque detector detects the motor current value. A control circuit that supplies a value corresponding to each of the detected torque, the temperature detected by the temperature detector, and the voltage detected by the voltage detector as an address and reads the motor current value from the storage device; and A drive circuit for supplying a current corresponding to the read motor current value to the motor.

[Action]

In the motor control drive device having the above configuration, values corresponding to the torque, temperature, and voltage detected by each detector are supplied to the storage device as an address, and the motor current value required for generating the required torque is read. A current corresponding to this is supplied to the motor. Therefore, without requiring a servo system having a feedback loop,
The required current can be supplied to the motor.

〔Example〕

FIG. 1 shows a configuration of an embodiment of a motor control drive device of the present invention applied to an electric power steering. In this figure, a motor 2 is a motor that drives a steering handle (not shown). The torque sensor 4 detects the torque when the steering wheel is turned left or right, and supplies a torque detection signal to a control circuit 8 configured by a microprocessor (MPU) via a sensor amplifier 6. When receiving the torque detection signal, the control circuit 8 turns on the power relay 10 and applies a voltage from the battery 12 to the drive circuit 14.

Detector 16 has a motor temperature detector 16T and a battery voltage detector 16V. The motor temperature detector 16T detects the temperature of the coil of the motor 2 and outputs a battery voltage detector 16V.
Detects the voltage of the battery 12, which is the power supply voltage of the motor 2, and supplies the detected voltage to the control circuit 8 via the interface 18.

The random access memory (RAM) 20 stores, as an address, a value corresponding to each motor torque, motor temperature, and battery voltage required during the operation of the motor 2 or within a predicted range, as an address. Stores the motor current value (PWM ON duty) necessary to generate the corresponding torque at the time of voltage. RAM20
If the address is composed of 16 bits, for example, the upper 6 bits may be assigned to the motor torque, the middle 5 bits may be assigned to the motor temperature, and the lower 5 bits may be assigned to the battery voltage.

FIG. 2 to FIG. 5 show the relative relationship of the data stored in the RAM 20. FIG.

As shown in FIG. 2, the ON duty of the PWM output from the control circuit 8 to the drive circuit 14 is basically directly proportional to the detected torque, and the ON duty is set to a larger value as the torque increases. .

Also, as shown in FIG. 3, the ON duty is substantially proportional to the temperature of the coil of the motor 2, and the higher the temperature, the greater the resistance of the coil.

On the other hand, as shown in FIG.
The ON duty of the PWM is inversely proportional, and the lower the battery voltage, the longer the ON duty.

Using these three data as parameters, a predetermined PWM ON duty is finally determined.

Therefore, as shown in FIG. 2, a reference PWM ON duty T is determined in accordance with the detected torque, and a correction coefficient K corresponding to the battery temperature and the coil temperature is determined as shown in FIG. Decision, the product of the two, the final PWM
The correction coefficient is also stored in the RAM 20 so that the ON duty of is obtained.

Thus, the control circuit 8 calculates the ON duty of the PWM according to the flowchart shown in FIG.

That is, first, the torque is read from the output of the torque sensor 4 and the reference duty T corresponding to this torque is set to RA
Read from M20 (steps S1 and S2). Next, the battery voltage and the motor temperature are read from the outputs of the battery voltage detector 16V and the motor temperature detector 16T (Step S3). Then, a correction coefficient K corresponding to the battery voltage and the motor temperature is calculated.
Read from RAM 20 (step S4). The reference duty T read in this way is multiplied by the correction coefficient K,
The final PWM ON duty is required (step S
Five).

The control circuit 8 supplies the drive circuit 14 with the ON-duty PWM signal thus obtained. The drive circuit 14 drives the motor 2 according to the PWM.

Therefore, by storing predetermined data in the RAM 20 in advance, the motor 2 can be used without using a feedback system.
Can be driven with predetermined characteristics.

Since the motor 2 is driven only for a relatively short period of time, for example, when changing the direction of the vehicle, the motor 2 has the same characteristics as the case where the servo is applied without increasing the amount of data stored in the RAM 20 so much. 2 can be driven.

In the above embodiment, the RAM is used as the storage device for storing the motor current value, but a read-on memory (ROM) may be used. However, using RAM has the advantage that it can cope with changes in motor characteristics.

Further, in the above-described embodiment, a microprocessor is used as the control circuit 8, but instead, hardware specially designed may be used.

Further, the present invention is not limited to a motor for driving a power steering, and can be used for driving a sun half, a window, and other objects.

〔effect〕

As described above, according to the motor control drive device of the present invention,
Even if the motor temperature and the power supply voltage fluctuate, the required torque can be generated from the motor without requiring a servo system with a feedback loop.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an embodiment of a motor control drive device of the present invention, FIG. 2 is a graph showing a relationship between torque and motor current, and FIG. 3 is a graph showing a relationship between motor temperature and motor current. FIG. 4 is a graph showing a relationship between a battery voltage and a motor current, FIG. 5 is a graph showing a relationship between a battery voltage and a motor temperature and a correction coefficient, and FIG. 6 is an embodiment of FIG. FIG. 7 is a block diagram showing a configuration of an example of a conventional motor control drive device. 2 ... motor, 4 ... torque sensor, 8 ... control circuit,
14 ... Drive circuit, 16T ... Motor temperature detector, 16V ... Battery voltage detector, 20 ... RAM.

Claims (1)

(57) [Claims] A torque detector for detecting a torque required of the motor; a temperature detector for detecting a temperature of the motor; a voltage detector for detecting a power supply voltage of the motor; A storage device that stores a motor current value required to generate the torque at the motor temperature and the motor power voltage as a value corresponding to each of the motor power voltages as an address, and that is detected by the torque detector. A control circuit that reads a motor current value from the storage device by supplying, as an address, a value corresponding to each of the torque, the temperature detected by the temperature detector, and the voltage detected by the voltage detector; and A drive circuit for supplying a current corresponding to the motor current value read by the circuit to the motor. Apparatus.