JPS62160085A - Stopping method for motor at predetermined angle - Google Patents

Abstract

PURPOSE:To smoothly stop a motor at a predetermined angle in a short time by releasing a reverse rotation command at stopping time when moving the motor from the normal state to a reverse state, and feedback controlling it through a motor driver. CONSTITUTION:When a normal rotation command is applied to a motor driver 15 and the rotation of a motor 14 arrives at a target angle predetermined in response to the predetermined angle while arriving at the predetermined angle from the start of rotating the motor 14, a reverse rotation command is applied to a motor driver 16. The stopping state when the motor 14 is shifted through a decelerating step from the normal rotation state to the reverse rotation state is detected by a zero detector 20, the reverse command is released upon detection, a deviation between the present rotary angle and the predetermined angle is output from a deviation counter 11, and the motor 14 is feedback-controlled through the driver 16 by the deviation.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a drive control method for a servo motor, and more particularly to a control method for stopping a motor at a predetermined rotation angle.

(Prior Art) Conventionally, various control methods have been proposed for controlling the rotation of a servo motor to a predetermined rotation angle position.

For example, as shown in FIG. 4, a direction signal SG1. It outputs a displacement angle signal SG2 consisting of a pulse train instructing the rotation angle (1 displacement angle) of the motor 2, and also outputs a position feedback signal @S03 consisting of a pulse train from the encoder 3 that detects the actual displacement angle of the motor 2. Output. and,
The width difference counter 1 sets a displacement angle signal SG2 consisting of a pulse train, subtracts the set value by a position feedback signal SG3 inputted in sequence, and outputs the count (direct) to the D/A converter 4. The D/A converter 4 converts this count value into an analog signal, amplifies the signal, and outputs it to the motor driver 5 as a speed setting voltage Vs.The motor driver 5 combines this speed setting voltage Vs with the actual motor 2 signal. Input the speed feedback voltage Vf from the tacho generator 6 that detects the speed, and calculate both voltages Vs,
The motor 2 is controlled based on Vf.

In this control method, the speed characteristics change as shown by the one-dot chain line in FIG. 2, and the displacement characteristics change as shown by the two-dot chain line in FIG.

(Problem to be Solved by the Invention) However, since the feedback signal SG3 from the encoder 3 and the speed feedback voltage Vf from the tacho generator 6 act to moderate acceleration and deceleration, fast response cannot be required. There wasn't. Also, if you try to bring out the full performance of the motor 2 and suddenly accelerate or decelerate, that is, if you try to make the response faster, the motor driver 5
When the amplification degree is increased, there is a problem in that the displacement characteristic overshoots and hunting occurs as shown in FIG.

(Object of the Invention) The object of the present invention is to solve the above-mentioned problems, to bring out the full performance of the motor, and to stop the motor smoothly and in a short time without causing overshoot to a predetermined rotation angle. The present invention provides a method for stopping a motor at a predetermined angle.

(Means for Solving the Problems) In order to achieve the above object, the present invention, after giving a normal rotation command to a motor driver, rotates the motor at a predetermined angle from the start of rotation until the motor reaches a predetermined angle. when the rotation of said motor reaches a correspondingly predetermined target angle;
A reverse rotation command is given to the motor driver.

Then, it detects a stopped state when the motor transitions from a normal rotation state to a reverse rotation state through a deceleration process, releases the reversal command upon detection, and also releases the reversal command and the deviation between the current rotation angle and the predetermined angle. Based on this, the motor is feedback-controlled via a motor driver to stop the motor at the predetermined angle.

(Function) By setting the target angle in advance, the timing to give a reverse rotation command to the motor driver is determined, and the timing determines the stop state when transitioning from a normal rotation state to a reverse rotation state in the deceleration process of the motor accompanying reverse drive. At the same time, the reversal command is canceled and the motor is stopped at a predetermined angle and held at that position by performing feedback control via the motor driver based on the deviation between the current rotation angle and the predetermined angle.

(Example) Hereinafter, an example embodying the present invention will be described based on the drawings.

FIG. 1 shows an electric block circuit of a motor predetermined angle stopping device, in which a deviation counter 11 includes a displacement angle signal 5GII consisting of a pulse train indicating a rotation angle (displacement angle), which will be described later, a position feedback pulse signal 5G12, and a reset signal 5.
G13 is input, the contents of the displacement angle signal 5G11 are set, and the contents are sent to the position feedback pulse signal 5G12.
Each time ``1'' is input, "1" is subtracted, and the contents at that time are outputted to the D/A converter 13 via the first gate circuit 12. Also, the deviation counter 11 receives a reset signal 5G13.
Its contents are reset based on The gate circuit 12 controls the transfer of the count contents output from the deviation counter 11 to the D/Δ comparator 13 based on a gate command signal to be described later.

The D/Δ converter 13 inputs the contents of the deviation counter 11 and also inputs the maximum acceleration control signal 5G to be described later.
14 and maximum deceleration control signal 5G15 are input. Then, when the maximum acceleration control signal 5G14 is input, the D/Δ converter 13 sets the speed setting voltage VS for accelerating the DC motor 14 to the maximum, and when the maximum deceleration control signal 5015 is input, the DC motor 14 is decelerated to the maximum ( In this embodiment, the speed setting voltage VS for maximum reverse driving) is applied to the motor driver 16 via the adder 15, and when the contents of the deviation counter 11 are input, the speed setting voltage VS based on the count contents is input to the motor driver 16. Output.

The adder 15 is configured to input a speed feedback voltage Vf, which will be described later, and a voltage obtained by adding the speed setting voltage Vs and the negative feedback voltage Vf is outputted to the motor driver 16 as the speed setting voltage VS. It turns out. Then, the motor driver 16 drives the load 17 by rotating the DC motor 14 at an acceleration corresponding to this speed setting voltage Vs.

The tacho generator 18 controls the rotation speed of the DC motor 14.
This detector is a detector for detecting rotational speed, and outputs a speed feedback voltage Vf proportional to the rotational speed to an adder 15 via one second gate circuit.

The zero detector 20 receives the speed feedback voltage Vf from the tacho generator 18, detects whether the rotation of the DC motor 14 has reached zero based on the voltage Vf, and outputs a cancel signal 5G16 when the rotation has reached zero. It is supposed to be done.

The encoder 21 is a detector that detects the actual angle of rotation of the DC motor 14, and outputs the position feedback pulse signal SG12 to the deviation counter 11 every time it rotates by a predetermined rotation angle.

A central processing unit (hereinafter referred to as CPU) 22 includes a program memory 23 that stores a control program and the CPU 2
It is provided with a working memory 24 that temporarily stores the results of the arithmetic processing of step 2, etc., and operates according to a control program stored in the program memory 23.

The program memory 23 stores data for each rotation angle of the displacement angle signal @5G11 to be output to the deviation counter 11 in order to rotate the DC motor 14 by a predetermined rotation angle (displacement angle) in the control program storage. is stored, and a rotation angle smaller than the rotation angle based on the displacement angle signal 5G11 is stored for each rotation angle in the displacement angle signal 5G11.

The target rotation angle is determined by accelerating the DC motor 14 at the maximum acceleration, decelerating it at the maximum deceleration (maximum reverse drive), and when the rotational speed of the motor 14 becomes zero, the actual DC motor at that time This value is obtained by experimenting in advance for each predetermined rotation angle so that the rotation angle of No. 14 is approximately equal to the predetermined rotation angle.

The CPU 22 controls the motor 1 from an external control device (not shown).
4 to a predetermined rotation angle (displacement angle) is input, and the rotation angle data corresponding to the displacement angle command signal 5G17 is read out and the displacement angle signal 5G11 as deviation counter 11
The CTC outputs the target rotation angle data via the input/output interface 25 and reads out the corresponding target rotation angle data.
Output to counter 26.

Further, the CPU 22 inputs a cancel signal SG16 from the zero detector 20, and outputs a gate command signal to the first and second gate circuits 12.19 via the input/output ink face 25. Further, the CPU 22 sends a maximum acceleration control signal 5G14 to the D/A converter 13 via the input/output interface 25 to accelerate the DC motor 14 at the maximum acceleration and a maximum acceleration control signal 5G14 to decelerate the DC motor 14 at the maximum deceleration (maximum reverse drive). Deceleration control signal 5G16
It is designed to output .

The CTC counter 26 is a subtraction counter that changes the content of the target rotation angle data by 11 every time the position feedback pulse signal 5G12 is input from the encoder 21.
” subtraction. When the content becomes "0", the CTC counter 26 outputs an interrupt signal to the CPU 22.

Next, the operation of the predetermined angle stopping device configured as described above will be explained.

Now, when the DC motor 14 is stopped, the CPU
22, the motor 14 is controlled by an external control device to a predetermined rotation angle θ.
When the displacement angle command signal 5G17 for rotating by S is output, the CPU 22 determines that the start has started, and immediately sends a gate command signal (contents are M) via the input/output interface 25 (step 1). The target rotation angle data of the target rotation angle θp with respect to the rotation angle es (the content is N, and the relationship IVI>N holds) is read from the program memory 23, and the rotation angle data is converted into the displacement angle signal 5G.
11 to the deviation counter 11 (step 3), and outputs the target rotation angle data to the CTC counter 26.
Step 4).

Further, the CPU 22 outputs the maximum acceleration control signal 5G14 to the D/'A converter 13 via the input/output interface 25 (step 5).

Therefore, since the first circuit 1 to circuit 12 are closed, the D/A converter 13 calculates the content M of the deviation counter 11.
is not input and only the maximum acceleration control signal 5G14 is input, so that the speed setting voltage Vs based on the control signal 5G14, that is, the value necessary to accelerate the DC motor 14 at the maximum acceleration. outputs the speed setting voltage Vs.

The motor driver 16 rotates the motor 14 at maximum acceleration based on this speed setting voltage VS. The encoder 21 detects the diameter and outputs a velocity feedback voltage vf thereof, and also outputs a position feedback pulse signal SGI2 every time the motor 14 rotates by a certain rotation angle. At this time, the speed feedback voltage Vf is not output to the adder 15 because the second gate circuit 19 is closed, but is output only to the zero detector 20.

On the other hand, the position feedback pulse signal 5G12 is output to the pan differential force "Kunta 11" and the CTC counter 26,
Each counter 11, 26 performs a subtraction operation each time the same pulse signal 5G12 is input.

The DC motor 14, which rotates at maximum acceleration, reaches the target rotation angle Op.
When the value N of the CTC counter 26 reaches "0", the CTC counter 26 outputs interrupt No. 13 to the CPU 22. In response to this interrupt signal (step 6), the CPU 22 immediately switches the control signal output to the D/A converter 13 from the maximum acceleration control signal 5G14 to the maximum deceleration control signal 5G15 (step 7).
.

Therefore, the D/A converter 13 decelerates the motor 14 at the maximum deceleration speed based on the maximum deceleration control (S).

Therefore, when the rotation angle of the DC motor 14 rotates from the start of rotation to the target rotation angle ■p, the DC motor 14 starts decelerating at the maximum deceleration.

When the rotational speed of the DC motor 14 is controlled to be at the maximum deceleration and the rotational speed of the DC motor 14 becomes "O", that is, the stopped state, the cancel signal 5 is output from the zero detector 20.
G16 is output.

In response to this cancel signal 5G16 (step 8), the CPU 22 stops outputting the maximum deceleration signal 5G15 to the D/A converter 13 (step 9),
A gate command signal for opening one of the first and second gate circuits 12.1 is output to the first and second gate circuits 12.19 (step 10).

Therefore, from this point on, the contents of the deviation counter 11 are validated and output to the D/Δ converter 13, and the speed feedback voltage Vf from the tacho generator 18 is output to the adder 15.

As a result, if the predetermined rotation angle θS has not been reached at this point and there is still a slight deviation (=es−■x; θX is the actual rotation angle), the DC current is calculated based on the contents of this width difference counter 11. The motor 14 is rotationally controlled] (Step 1
1). At this time, the content of the counter 11 is subtracted to a small value even if there is a width difference, so the DC motor 1
4 is smoothly controlled to rotate until it reaches a rotation angle O3, stops at that rotation position, and maintains its position.

In this way, in this embodiment, when rotating the DC motor 14 to a predetermined rotation angle θS, the target rotation angle ■p is set in advance for the same rotation angle j es, and the target rotation angle ■p Until then, the rotation of the motor 14 is controlled at the maximum acceleration, and when it rotates to the target rotation angle ■p, it is immediately decelerated at the maximum deceleration, and the rotational speed of the motor 14 reaches zero based on this deceleration. Since the rotation is controlled based on the deviation between the rotation angle θX of the motor 14 at that time and the predetermined rotation angle θS, the performance of the DC motor 14 can be brought out to the full and the rotation angle es can be reached to the predetermined rotation angle es. Rotation can be stopped smoothly and in a short time without overshooting.

Although the present embodiment describes controlling the rotation angle of the DC motor 14, the present invention is not limited to this, and it goes without saying that the invention may be applied to, for example, rotation control of an AC servo motor.

The present invention relates to a control device for the drive motor of an automatic embroidery sewing machine having a drive device and a feed device configured to move the work cloth by a predetermined distance in the front, back, left, and right directions with respect to the needle in proportion to the amount of rotation of the needle. can be adopted.

As a result, the movement of the workpiece cloth relative to the needle can be quickly completed within a limited time until the needle that has been lifted and separated from the workpiece cloth is lowered and enters the workpiece cloth, so that the needle can move up and down. This makes it possible to increase the speed of automatic embroidery machines, which have traditionally been difficult to perform at high speeds.

(Effects of the Invention) As detailed above, according to the present invention, it is possible to bring out the full performance of the motor and stop the rotation smoothly and in a short time without overshooting to a predetermined rotation angle. It has excellent effects.

[Brief explanation of drawings]

The electrical block circuit diagram of the control device, FIG. 5, is a diagram showing the characteristics of a conventional motor. In the figure, 11 is a C-t counter, 12 is the first goo 1~circuit, 13 is a D/A converter, 14 is a DC motor, 15
is an adder, 16 is a motor driver, 18 is a tacho generator, 1 is a second gate circuit, 20 is a zero detector, 2
1 is a central processing unit (CPU), 23 is a program memory, and 26 is a CTC counter.

Claims (1)

[Claims] 1. The motor (14) is driven by a motor driver (16), and the motor (14) is rotated at a predetermined angle (■s) from the start of rotation.
), the motor driver (
A forward rotation command (SG14) is given to the motor (16), and from the start of rotation of the motor (14) until reaching the predetermined angle (■s), the motor (SG14) is predetermined corresponding to the predetermined angle (■s). The motor (
When the rotation of the motor driver (14) has been reached, the motor driver (16)
), the motor (14) detects a stopped state when the motor (14) transitions from a normal rotation state to a reverse rotation state through a deceleration process, and upon that detection, releases the reverse rotation command (SG15). At the same time, the motor (14) is controlled by the motor driver (16) based on the deviation between the current rotation angle (■x) and the predetermined angle (■s).
), the predetermined angle (■s
) A method for stopping a motor at a predetermined angle, the method comprising stopping the motor (14) at a predetermined angle.