JPH0417587A - Motor control device - Google Patents

Abstract

PURPOSE:To enable a motor to be stopped stably and readily by turning off a position command signal and a speed command signal in response to an emergency stop command and by reducing each gain at a speed control part and a current control part. CONSTITUTION:A position command signal B and a speed command signal D are turned off at a training timing of a limit signal A. At this time, since a speed feedback signal overshoots, a speed gain Kv at a speed control part 4 is reduced at a trailing edge of the limit signal A and is controlled as in E'. Also, since current feedback signal overshoots, a current gain KI at a current control part 6 is reduced at a trailing edge of the limit signal A and is controlled as in F', thus enabling a motor 2 to be subjected to emergency stop safely so that a flow needed for stop can be minimized.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a motor control device, and more particularly to a motor stop control system.

BACKGROUND OF THE INVENTION In controlling motors used in NC machine tools, industrial robots, etc., it is necessary to control the motors to make an emergency stop when a limit signal, which is a motor stop command, is input. In this case, emergency stop control is performed to stably stop the motor and to minimize the so-called flow rate required for stopping.

FIG. 3 is a block diagram of such a conventional emergency stop control device. The position control section 1 generates a speed command signal using a position command signal B given in the form of a pulse train and a position feedback signal C from an encoder 3 of the motor 2.

The speed control section 4 generates a current command signal G using a speed command signal given in the form of a pulse train and a speed feedback signal E from the speed detection section 5 of the motor 2.

The current control section 6 generates a motor drive signal using a current command signal G given in the form of a pulse train and a current feed pack signal F from the current detection section 7 of the motor 2.

The stop control section 8 controls a gate 9 for stopping the position command signal B in order to emergency stop the motor 2 based on the limit signal A.

FIG. 4 is a waveform diagram of each part of the circuit block showing the operation of the circuit block of FIG. There is.

In response to the fall timing of the limit signal A, the position command signal B is turned off by the gate 9, and the position command to the position control section 1 is cut off. Therefore, the position feedback signal C1, the speed command signal, and the speed feedback signal E are each gradually decreased to perform motor stop control.

In this case, it is necessary that the so-called flow amount from when the limit signal A falls until the motor 2 stops is small.

Motor application systems such as machine tools and industrial robots have limited movable ranges, so for the purpose of collision prevention, the effective movable range is set within the movable range, and the effective movable range is set at maximum speed. However, it is usually designed in advance to perform emergency stop processing in response to an emergency stop command and to stop within the movable range.

However, as motor application systems become faster and more sophisticated, there is a growing demand to further increase the maximum speed and expand the effective movable range.

In the motor emergency stop control system shown in FIG. 3, the flow rate of the motor is large, making it difficult to increase the motor speed beyond the current level.

OBJECTS OF THE INVENTION An object of the present invention is to provide a motor control device that can reduce the flow rate as much as possible during an emergency motor stop.

Composition of the Invention A motor control device according to the present invention includes a position control section that generates a speed command signal using a position command signal and a position feedback signal from an encoder of the motor, and a position control section that generates a speed command signal using a position command signal and a position feedback signal from an encoder of the motor; a speed control unit that generates a current command signal using the speed feedback signal of the
a current control unit that generates a drive signal for the motor using the current command signal and a current fitback signal from a current detection unit of the motor; and a current control unit that generates a drive signal for the motor using the current command signal and a current feedback signal from a current detection unit of the motor, and a current control unit that generates the position command signal and the speed command signal in response to a motor stop command. means for controlling the
The apparatus is characterized in that it includes means for decreasing each gain of the speed control section and the current control section in response to the position command signal.

Embodiments Next, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram of an embodiment of the present invention, and parts equivalent to those in FIG. 3 are designated by the same reference numerals. To describe only the differences from FIG. 3, a gate 10 is provided to turn off the speed command signal, which is the manual input of the speed control section 4, and this gate 10 is controlled to be turned off by the stop control section 8.

Further, the respective gains of the speed control section 4 and the current control section 6, that is, the speed gain KV and the current gain Kl, are controlled to decrease by the stop control section 8.

FIG. 2 is a signal waveform diagram of each part showing the operation of the blocks in FIG. 1. At the falling timing of the limit signal A, the position command signal B and the speed command signal are disconnected. At this time, the speed feedback signal overshoots as shown in FIG. 2(E), so the limit signal A falls and the speed gain KV of the speed control section 4 is decreased to perform control as shown in FIG. 2(E-).

Similarly, since the current feedback signal also overshoots as shown in FIG. 2 (F), the current gain of the current control section 6 is decreased by 1 at the fall to the limit signal, and control is performed as shown in (F').

By doing this, it is possible to perform an emergency stop stably and with the flow amount required for stopping the flow in the shortest possible time.

Effects of the Invention As shown above, according to the present invention, in response to an emergency stop command, the position command signal and the speed command signal are turned off, and
Since each gain of the speed control section and the current control section is reduced, there is an effect that the motor can be stopped stably and quickly.

[Brief explanation of drawings]

FIG. 1 is a system block diagram of an embodiment of the present invention, FIG. 2 is a signal waveform diagram of each part showing the operation of the blocks in FIG. 1, and FIG.
The figure is a system block diagram showing the conventional technology.
FIG. 4 is a signal waveform diagram of each part showing the operation of the blocks in the figure. Explanation of symbols of main parts 1... Position control section 2... Motor 8... Stop control section 3... Encoder 9, 10...
Gate 4...Speed control section 5...Speed detection section 6...Current control section 7...Current detection section (A) Limit trigger (B) Okio 1j4 Ikichi-go (F5 optical feedback (g-go whistle 2 fig.

Claims (1)

[Claims] (1) A position control section that generates a speed command signal using a position command signal and a position feedback signal from an encoder of the motor, and a position control section that uses the speed command signal and a speed feedback signal from the speed detection section of the motor. a speed control unit that generates a current command signal; a current control unit that generates a drive signal for the motor using the current command signal and a current feedback signal from a current detection unit of the motor; and a current control unit that responds to a motor stop command. and means for controlling each gain of the speed control section and the current control section to decrease in response to the position command signal. Control device.