JPH04185290A - Motor controller - Google Patents

Abstract

PURPOSE:To reduce rotation unevenness and stabilize the rotation of a motor substantially by a method wherein a processing part which processes a correction function having a detected rotation position as a parameter and a correcting part which corrects a transfer function having the revolution of the motor as a parameter with the processed correction function are provided. CONSTITUTION:A rotation position detecting circuit 11 detects the number of signal pulses of a revolution omega counted from a time when a reference pulse rises as a reference every time when the pulse signal of the revolution omega is detected and the number is outputted as the signal of a rotation position theta. If the signal of the revolution omega and the signal of the rotation position theta are inputted to a first processing part 9 and a second processing part 12 respectively, a transfer function f(omega) is calculated by using the signal of the inputted revolution omega and a correction function g(theta) is calculated by using the inputted rotation position theta and the calculated results are added by an adder 20. With this constitution, the transfer function f(omega) is corrected by the correction function g(theta).

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a motor control device using a microcomputer.

[Conventional technology]

FIG. 3 is a block diagram of a conventional motor control device that controls the rotational speed of a motor using a microcomputer. Pulses generated in accordance with the rotation speed of the motor 1 are input to a rotation speed pulse detection circuit 7, and the detection output of the rotation speed pulse detection circuit 7 is input to a rotation speed detection circuit 8 in the microcomputer 4. . The output of the rotational speed detection circuit 8 is provided to an arithmetic unit 9 within the microcomputer 4. The calculation result of the calculation section 9 is input to the pulse width modulation circuit 5. A pulse signal output from the pulse width modulation circuit 5 is input to the amplifier 3 via a filter 6. The output of the amplifier 3 is input to a driver IC 2 for driving the motor, and the output is given to the motor 1.

Next, the operation of this motor control device will be explained.

When the motor 1 is started, a plurality of rotation speed pulses whose pulse width changes according to the rotation speed ω of the motor 1 are outputted from the motor 1 during one rotation of the motor 1, and the rotation speed pulse detection circuit 7 9. When the rotation speed pulse is input to the rotation speed detection circuit 8, the pulse width is converted into a digital value and the rotation speed ω is input to the rotation speed detection circuit 8. It is given to the arithmetic unit 9 as a signal. Thereby, the calculation unit 9 calculates the transfer function f(ω) using the signal of the rotational speed ω. The calculation result is input to a pulse width modulation circuit 5, converted into a pulse signal, and then converted into an analog signal by a filter 6. After this analog signal is amplified by the amplifier 3, the driver IC 2
The voltage is input to the motor 1, converted into a predetermined drive voltage that should stably rotate the motor 1, and the drive voltage is applied to the motor 1.

Through such control, the rotational speed ω of the motor 1 is controlled.

[Problem to be solved by the invention]

By the way, due to variations in manufacturing work, motors
Characteristics such as the moment of inertia and the inductance of the motor coil are slightly different for each motor.

Therefore, slight rotational unevenness depending on the rotational position occurs during one rotation of the motor. Because of the rotational unevenness, the correspondence between the motor torque and the correction amount varies slightly depending on the rotational position. Therefore, there is a problem in that the rotation of the motor cannot be controlled and the motor cannot be rotated stably.

In view of this problem, the present invention corrects the drive voltage of the motor according to the rotational position of the motor, reduces rotational irregularities that occur during one rotation of the motor, and makes it possible to extremely stabilize the rotation of the motor. The purpose is to propose a motor control device.

[Means to solve the problem]

The motor control device according to the present invention includes a circuit that detects the rotational position of the motor, a calculation unit that calculates a correction function that uses the detected rotational position as a parameter, and a calculation unit that uses the calculated correction function to use the rotational speed of the motor as a parameter. The configuration includes a correction section that corrects the transfer function.

[Effect]

The correspondence between the torque of the motor and the drive voltage applied to the motor can be approximated as a correction function using the rotational position of the motor as a parameter. When the rotational position of the motor is detected by the rotational position detection circuit, the calculation section calculates a correction function in accordance with the detected rotational position of the motor. The calculated correction function corrects the transfer function using the motor rotation speed as a parameter. The motor is controlled using the corrected transfer function.

As a result, the rotation of the motor is always stable regardless of the rotational position of the motor.

(Example〕 The present invention will be described in detail below with reference to drawings showing embodiments thereof.

FIG. 1 is a block diagram of a motor control device according to the present invention. Pulses generated in accordance with the rotational speed of the motor 1 are input to a rotational speed pulse detection circuit 7 and a reference pulse detection circuit 10. The detection output of the rotational speed pulse detection circuit 7 is input to a rotational speed detection circuit 8 and a rotational position detection circuit 11 within the microcomputer 4. The detection output of the reference pulse detection circuit 10 is manually input to the rotational position detection circuit 11. A signal of the rotational speed ω outputted by the rotational speed detection circuit 8 is manually inputted to the first calculation unit 9 in the microcomputer 4, and a signal of the rotational position θ is inputted to the second calculation unit 12.

The calculation results of the first calculation section 9 and the calculation results of the second calculation section 12 are provided to the adder 20. The addition output of the adder 20 is given to the pulse width (P-1 modulation circuit 5), and the pulse signal outputted by it is input to the amplifier 3 via the filter 6.The output of the amplifier 3 is Driver IC2
and its output is given to motor 1.

FIG. 2 is a waveform diagram showing the relationship among the rotational position θ of the motor 1, the reference pulse, the rotational speed pulse, and the amount of correction for the transfer function.

Next, the operation of the motor control device configured as described above will be explained with reference to FIG.

In the memory (not shown) of the microcomputer 4,
A transfer function f (ω) and a correction function g (θ), which are obtained by determining the relationship between the torque of the motor 1 and the correction amount with respect to the rotational position θ of the motor 1, are stored in advance.

For example, when assembling a control device with a correction function g(θ), the characteristics of each control device are measured, and each correction function g(θ) is
Determine.

Here, the rotational position θ of the motor 1 is as shown in Fig. 2 (b), (c
) as shown in Figure 2 (
The rising edge of the rotational speed pulse shown in c) is defined as Oo, and each time the rotational speed pulse rises, it falls after 30' elapses. Further, the correction function g(θ) expresses the amount of correction for the transfer function r(ω) for each rotational position θ as a function of the rotational position θ, as shown in FIG. 2(d).

Now, when the motor 1 is started, the rotation of the motor 1 generates a rotation speed pulse whose pulse width changes according to the rotation speed ω of the motor l. A plurality of rotational speed pulses are output during one rotation of the motor 1 , and the rotational speed pulse detection circuit 7 detects the rotational speed pulses, and inputs the detection output to the rotational speed detection circuit 8 . Further, a reference pulse is generated every time the motor 1 makes one rotation according to a predetermined rotational position of the motor 1, and the rotational position pulse detection circuit 10 detects the reference pulse. When a rotational speed pulse is input to the rotational speed detection circuit 8, the pulse width is converted into a digital value and output as a signal of the rotational speed ω. Furthermore, each time a signal of rotational speed ω is detected, the rotational position detection circuit 11 uses the rising time of the reference pulse as a reference, and detects how many rotational speed pulses have been generated since the reference pulse was output by using the signal of rotational position θ. Output as . When the signal of the rotational speed ω and the signal of the rotational position θ are input to the first calculation unit 9 and the second calculation unit 12 in the microcomputer 4,
Transfer function f (ω
) is calculated, and the correction function g(θ
), and the adder 20 adds the calculation results. As a result, the transfer function f(ω) becomes the correction function g(θ)
Corrected by

The addition output of the adder 20 is converted into a pulse signal by the pulse width modulation circuit 5, and then converted into an analog signal by the filter 6. After this analog signal is amplified by the amplifier 3, it is input to the driver IC 2, where it is converted into a drive voltage to drive the motor 1, and is applied to the motor 1.

With such control, control is performed according to the rotational speed ω of the motor 1, and at the same time, control is performed according to the rotational position θ of the motor 1. Thereby, minute rotational irregularities of the motor 1 depending on the rotational position θ can be eliminated. The motor 1 rotates stably regardless of the rotational position θ.

In this embodiment, a function g(θ) having the rotational position θ of the motor 1 as a parameter is used as the correction function, but the present invention is not limited to this, and for example, a correction function g including the rotational speed ω as a parameter may be used. (θ, ω) may be used.

In this case, the rotation of the motor I can be controlled with higher precision.

In addition, in this embodiment, the transfer function f(ω) and the correction function g
Although the calculation of (θ) was performed using software, some or all of these processes can also be performed using hardware.

Furthermore, in this embodiment, the microcomputer 4 has a built-in rotational speed detection circuit 8 and a rotational position detection circuit 11, but the invention is not limited to this, and a part or all of these circuits can be incorporated into the microcomputer 4. It may also be an external circuit.

〔Effect of the invention〕

As detailed above, according to the present invention, the drive voltage of the motor is controlled according to the rotational speed and rotational position of the motor, so that due to variations in the characteristics of the motor, the rotation that occurs during one rotation of the motor, Can eliminate slight rotational irregularities that depend on position. Therefore, the present invention has the excellent effect of providing a motor control device that can stably rotate a motor regardless of its rotational position.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a motor control device according to the present invention, FIG. 2 is a waveform diagram showing the relationship between the rotational position of the motor, the reference pulse, the rotational speed pulse, and the correction amount with respect to the transfer function.
The figure is a block diagram of a conventional motor control device. 1...Motor 3...Amplifier 4...Microcomputer 7...Rotation speed pulse detection circuit 8...
Rotation speed detection circuit 9... First calculation unit 10... Reference pulse detection circuit 11... Rotation position detection circuit 12...
-Second calculation unit 20...adder In the drawings, the same reference numerals indicate the same or equivalent parts. Agent Masuo Oiwa

Claims (1)

[Claims] (1) A motor control device that detects the rotational speed of a motor and controls the motor based on a transfer function using the detected rotational speed as a parameter, comprising: a circuit that detects the rotational position of the motor; and a circuit that detects the rotational position of the motor; A motor control device comprising: a calculation section that calculates a correction function used as a parameter; and a correction section that corrects the transfer function using the calculated correction function.