JPS63124788A - Drive for servomotor - Google Patents

Abstract

PURPOSE:To prevent the uncontrolled operation of a servomotor by out putting a cryptographic signal together with a position command signal from a motor- position command control section, deciding whether the cryptographic signal is a predetermined signal and then driving the servomotor. CONSTITUTION:A motor-position command control section 11 outputs a cryptographic signal together with a position command signal for commanding the position of a motor. When the operation of each section is normal, the state in which the results of cryptographic decoding in a cryptographic-signal decoding section 12 is brought to a coincided one. Consequently, the position command signal is input to a servomotor drive circuit 13 while a revolution permission signal is input to a revolution stoppage control section 14. When uncontrolled operation or a malfunction is generated in the motor-position command control section 11, the state in which the results of cryptographic decoding in the cryptographic command decoding section 12 do not coincide is brought about. Accordingly, the revolution permission signal is not input to the revolution stoppage control section 14, and a motor stoppage command signal is generated and an emergency stop section 18 stops a servomotor 15.

Description

DETAILED DESCRIPTION OF THE INVENTION [Objective of the Invention (Industrial Application Field) The present invention relates to a servo motor drive device, and particularly to a control circuit for preventing runaway of a servo motor.

(Prior Art) A conventional servo motor drive circuit is configured as shown in FIG. That is, the servo motor drive circuit 21 drives the servo motor 23 according to the control signal from the motor position command control section 22, and the servo motor 23 moves the driven section 24 to a desired position or angle and then stops it. do. In this case, the motor rotation detecting section 25 detects the rotational state of the scissor motor 23, and the detection result is fed back to the servo motor drive circuit 21.

26 is caused by a runaway operation of the motor position command control section 22 (due to a runaway program of the micro combinator used, etc.), hardware damage to the servo motor drive circuit 2, or the control section 22 or the control section 22 due to an external noise signal. This is an emergency stop section that is manually operated to force the servo motor 23 to an emergency stop and stop the runaway when the servo motor 23 runs out of control due to a malfunction of the drive circuit 2 or the like.

However, with the servo motor and drive device as described above, it is necessary for a human to detect when the servo motor 23 runs out of control, and it is necessary to manually operate the emergency stop section 26 to stop the runaway. The time required from when the servo motor 23 starts running out of control until it stops running out of control becomes longer, and there is a risk that serious damage or accidents may occur due to runaway.

For example, if the servo motor drive device described above is used in a production line at a factory, product quality and yield may be reduced. Furthermore, since the servo motor drive circuit 2 responds to the runaway of the motor position command control unit 22, which is one of the causes of runaway of the servo motor 23, there is the problem that runaway of the servo motor is likely to occur. there were.

(Problems to be Solved by the Invention) The present invention solves the problem of the servo motor running out of control due to the runaway of the motor position command control unit as described above, and the problem of the servo motor running out of control from the start of the runaway to the manual operation to stop the runaway. This was created to solve the problem of long time required, and can prevent the servo motor from running out of control due to runaway of the motor position command control unit. An object of the present invention is to provide a servo motor drive device that can stop runaway in a short time.

[Structure of the Invention] (Means for Solving the Problems) The servo motor drive device of the present invention causes a motor position command control section to output a code signal together with a position command signal, and converts the code signal from the control section into a code signal. The decoder decodes the code, determines whether it is a predetermined code, and, depending on the determination result, controls whether or not the position command signal from the motor position command control section can pass, and also determines whether or not the rotation permission signal can be output. Based on the position command signal that passes through this decoder, the servo motor drive circuit outputs a scissor. Control is performed to drive the motor and to prohibit operation of the motor emergency stop section when the rotation permission signal is output. Further, when a rotation detection output is generated from the servo motor rotation detection section during the drive output stop period of the servo motor drive circuit, a motor stop command signal is output to the motor emergency stop section to bring the servo motor to an emergency stop. There is.

(Function) Therefore, if the motor position command control unit runs out of control or makes one operation, the decryption results will be inconsistent, and the servo motor will come to an emergency stop.

Furthermore, if the servo motor should be in a stopped state and the motor runs out of control due to hardware damage or malfunction of the motor drive circuit, this is automatically detected and an emergency stop is performed.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

In the servo motor drive device shown in Fig. 1, reference numeral 11 is a motor position command control unit, which uses a micro combinator, and uses a position command signal for commanding the motor position as well as a code signal (password, keyword, PIN number, etc.). etc.) is output. Reference numeral 12 denotes a coded signal decoding unit which decodes the coded signal from the motor position command control unit 11 and, if it matches a predetermined code, decodes the coded signal from the motor position command control unit 11.
A position command signal is sent to the servo motor drive circuit 13, and a rotation permission signal is sent to the rotation stop control section 14. 15
is a servo motor driven by the servo motor drive circuit 13, and drives the driven section 16.

Reference numeral 17 denotes a motor rotation detection section that detects the rotational state of the servo motor J50 and feeds the detection result back to the servo motor drive circuit 3. Reference numeral 18 denotes an emergency stop section for forcibly stopping the rotation of the servo motor 15, and performs the above-mentioned stopping operation when receiving a motor stop command signal from the rotation stop control section 14. 14 does not generate a motor stop command signal when it receives a rotation permission signal from the coded command decoder 12, but detects motor rotation during the drive output stop period of the servo motor drive circuit I3 even when it receives a rotation permission signal. When the motor rotation detection signal is input from section 17 (when the motor runs out of control)
When detected, a motor stop command signal is generated.

Next, the operation of the servo motor drive device will be explained.

(1) When the operation of each part is normal, the decryption result at the encrypted signal M connection part 12 is in a matching state, so the 1 position command signal is input to the servo motor drive circuit 13.

A rotation permission signal is input to the rotation stop control section 14, and a motor stop command is not output. Therefore, the servo motor 15 rotates and drives the driven portion 16 to a desired position or angle.

(2) If a runaway or malfunction occurs in the motor position command control unit 1, the decryption result in the decryption command decoding unit 12 will be inconsistent, so the position command signal will not be input to the servo motor and drive circuit 13. is prohibited and the rotation permission signal is no longer input to the rotation stop control unit J4, so a motor stop command signal is generated and the emergency stop unit 18 stops the servo motor 15.
to stop.

(3) When the servo motor 15 should be in a stopped state,
If hardware damage or malfunction occurs in the motor drive circuit 13, the servo motor will fail! 5 runs out of control, a motor rotation detection signal is generated from the motor rotation detection section 17, a motor stop command signal is generated from the rotation stop control section 14, and the emergency stop section 18 stops the servo motor 15.

According to the above-described servo motor drive device, the motor position command control unit 11 outputs a code signal along with the position command signal, and the code command decoding unit decodes the code signal to determine whether it is a predetermined code. Since it is determined whether or not the position command signal is correct by determining whether the position command signal is correct or not, it is possible to prevent the servo motor from running out of control due to runaway or malfunction of the motor position command control section.

In addition, even if the servo motor runs out of control due to hardware damage or malfunction of the servo motor drive circuit when the servo motor should be in a stopped state, the output of the motor rotation detector that detects the rotation of the servo motor at this time will The rotation stop section automatically detects runaway and generates a motor stop command signal to control the servo motor to an emergency stop, so runaway can be stopped in a short time after runaway starts, and runaway can be stopped quickly. It is possible to prevent or reduce damages and accidents.

[Effects of the Invention] As described above, the servo motor drive device of the present invention can prevent runaway of the servo motor due to runaway or malfunction of the motor position command control unit, and can automatically prevent runaway of the servo motor. Since runaway can be automatically stopped by detecting the situation, it is possible to prevent or reduce the adverse effects of runaway on the nuclear moving parts.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the servo motor drive device of the present invention, and FIG. 2 is a block diagram showing a conventional servo motor drive device. DESCRIPTION OF SYMBOLS 11... Motor position command control part, 12... Code signal decoding part, 13... Servo motor drive circuit, 14...
Motor rotation stop control section, 15... Servo motor, 17
...Motor rotation detection section, 18...Emergency stop section.

Claims (1)

[Claims] a motor position command control unit that outputs a code signal together with a position command signal for commanding the rotational position of the servo motor; and a motor position command control unit that decodes the code signal from this control unit and controls the motor according to whether or not it is a predetermined code. A coded signal decoding section that controls whether or not the position command signal from the position command control section can pass and whether or not a rotation permission signal can be output; and a servo motor drive that drives the servo motor based on the position command signal that has passed through the decoding section. a motor rotation detecting section that detects the rotation of the servo motor, and a drive output of the servo motor drive circuit that stops when a rotation permission signal is not given from the encoded signal decoding section or even if a rotation permission signal is given. a motor rotation stop control unit that generates a motor stop command signal when a rotation detection output is generated from the motor rotation detection unit during the period;
A servo motor drive device comprising: an emergency stop section that receives a motor stop command signal from the control section and stops the servo motor.