JPH05146989A - Control device for industrial robot - Google Patents

Abstract

PURPOSE:To improve safety by reducing the coasting quantity at the time of emergency stop of an industrial robot. CONSTITUTION:When an emergency stop signal is inputted, a switch 12 is switched to set the speed command value omega* to zero, and a position controller 11 is cut off. The output of a current controller 14 is directed by the torque command value i* to set the braking torque of a servo motor 1 to the maximum. All control systems are made effective, and the position command value theta*is set to the deceleration command value having the minimum value required to stop a robot.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for controlling an industrial robot by an electric servo.

[0002]

2. Description of the Related Art FIG. 2 is a block diagram of a control system showing a conventional controller for an industrial robot.

In the figure, (1) is a servo motor for operating a robot, (2) is a contact for connecting terminals of the servo motor (1), (3) is an electromagnetic brake directly connected to the servo motor (1), (4) is an encoder that is connected to the servo motor (1) and outputs an output corresponding to the movement amount of the robot, and (5) is a position controller, speed controller and current controller, and the position (movement amount)
A controller that adjusts the voltage applied to the servomotor (1) by inputting the command value θ *, position feedback value θ, speed feedback value ω, and current feedback value i. (6) amplifies the output of the controller (5) The power amplifier (7) is a current detector that detects the output current of the power amplifier (6) and generates a current feedback value i.

The conventional controller for the industrial robot is constructed as described above, and the servo motor (1) is controlled by the controller (5). When an emergency stop signal is input during the operation of this control system, the servomotor (1) is disconnected from the power supply and enters a swashcoat state. At this time, the electromagnetic brake (3) is operated and is braked by the friction braking force. At the same time, the terminals of the servo motor (1) are connected by the contact (2),
(1) is braked by generating electric braking force.

[0005]

The conventional industrial robot controller as described above uses both the friction braking force and the voltage braking force, so that the braking force is limited and the amount of sprinting of the robot is limited. There is a problem that it becomes large and safety cannot be secured. Further, although the electromagnetic brake (3) is provided for holding the robot, it also serves as an emergency stop, so that there is a problem that the life of the electromagnetic brake (3) is shortened.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a control device for an industrial robot capable of reducing the amount of sprinting of the robot.

[0007]

A control device for an industrial robot according to a first aspect of the present invention is adapted to make a speed command value zero when an emergency stop signal is inputted.

The industrial robot controller according to the second aspect of the present invention sets the movement command value to the minimum value required to stop the robot when the emergency stop signal is input. Is.

[0009]

In the first aspect of the present invention, since the speed command value is set to zero during an emergency stop, the current (torque) command value commands the maximum braking torque.

Further, in the second aspect of the present invention, since the movement amount command value is set to the minimum value necessary for stopping the robot at the time of emergency stop, the robot decelerates and stops according to the deceleration command value.

[0011]

【Example】

Example 1. FIG. 1 is a block diagram of a control system showing an embodiment of the present invention, and the same parts as those of the conventional device are designated by the same reference numerals.

In the figure, (11) is a position controller which inputs the position command value θ * and the position feedback value θ and outputs the speed command value ω *, and (12) is the speed controller ω * and the speed command value zero. The switch that switches between and forms a speed command value reset device. (13) is a speed controller that inputs the speed command value ω * and the speed feedback value ω and outputs the current (torque) command value i *, and (14) is the current (torque) command value i * and the current feedback value. It is a current controller for inputting i and controlling the servo motor (1) via the power amplifier (6).

Next, the operation of this embodiment will be described. This control system is composed of three control loops, a position control loop, a speed control loop and a current control loop, and is controlled in the same manner as the conventional device.

When the emergency stop signal is input, the electromagnetic brake (3) operates as described above. On the other hand, the switch (12) switches the speed command value ω * to zero, and the position controller (11) is cut off. When the speed command value ω * becomes zero, the output of the current controller (14) is commanded so that the braking torque of the servo motor (1) becomes the maximum torque, and in the shortest time, the servo motor (1), namely, The robot stops.

The current (torque) command value i * is output as a value obtained by multiplying the difference between the speed command value ω * and the speed feedback value ω by a predetermined coefficient. (1) The speed controller (13) has a limiter so that a torque greater than the maximum torque is not commanded individually.

Example 2. In the first embodiment, the speed command value ω * is switched to zero at the time of emergency stop, but this makes all of the control system of FIG. 1 effective, and the switch (12) is not switched (necessary), Even if the position command value θ * is set to the position command value that has the minimum value necessary for the robot to stop using the movement command value setting device (not shown), the robot will not stop in the shortest time. Can be expected.

Embodiment 3. In the first embodiment, the speed command value ω * may be set to zero by switching the switch (12) without operating the electromagnetic brake (3).

[0018]

As described above, in the first aspect of the present invention, when the emergency stop signal is input, the speed command value of the robot is set to zero, so that the current (torque) command value is the maximum torque. Command. In the second aspect of the invention, the position command value is set to the minimum value required to stop the robot, so that the robot decelerates and stops according to the deceleration command value. By these, there is an effect that the amount of sprinting of the robot can be reduced and safety can be secured.

[Brief description of drawings]

FIG. 1 is a block diagram of a control system showing a first embodiment of the present invention.

FIG. 2 is a block diagram of a control system showing a conventional controller for an industrial robot.

[Explanation of symbols]

 1 Servo motor 4 Encoder 6 Power amplifier 7 Current detector 11 Position controller 12 Speed command value reset device (switch) 13 Speed controller 14 Current controller θ * Travel command value (position command value) θ Travel feedback value ( Position feedback value) ω * Speed command value ω Speed feedback value i * Current command value i Current feedback value

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[Procedure amendment]

[Submission date] July 30, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0004

[Correction method] Change

[Correction content]

The conventional controller for the industrial robot is constructed as described above, and the servo motor (1) is controlled by the controller (5). If an emergency stop signal is input during operation of this control system, the servo motor (1) will be disconnected from the power supply.
The 惰 run state. At this time, the electromagnetic brake (3) is operated and is braked by the friction braking force. At the same time, the terminals of the servo motor (1) are connected by the contact (2),
(1) is braked by generating electric braking force.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0005

[Correction method] Change

[Correction content]

[0005]

The conventional industrial robot controller as described above uses both the friction braking force and the voltage braking force, so that there is a limit to the braking force.
惰 Hashiryou is increased, there is a problem that can not be ensured safety. Further, although the electromagnetic brake (3) is provided for holding the robot, it also serves as an emergency stop, so that there is a problem that the life of the electromagnetic brake (3) is shortened.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0006

[Correction method] Change

[Correction content]

[0006] The present invention has been made to solve the above problems, and an object thereof is to provide a control apparatus for an industrial robot to be able to reduce the 惰 Hashiryou robot.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0018

[Correction method] Change

[Correction content]

[0018]

As described above, in the first aspect of the present invention, when the emergency stop signal is input, the speed command value of the robot is set to zero, so that the current (torque) command value is the maximum torque. Command. In the second aspect of the invention, the position command value is set to the minimum value required to stop the robot, so that the robot decelerates and stops according to the deceleration command value. These, an effect that can ensure safety by reducing the 惰 Hashiryou robot.

Claims (2)

[Claims] 1. A position controller for inputting a movement amount command value and a movement amount feedback value of a robot to generate a speed instruction value, and a velocity for inputting the speed instruction value and the velocity feedback value to generate a current instruction value. A controller, a current controller that inputs the current command value and the current feedback value to adjust the voltage applied to the motor, and a speed command value reset device that makes the speed command value zero when an external emergency stop signal is input. A control device for an industrial robot that is equipped with. 2. A position controller for inputting a movement amount command value and a movement amount feedback value of a robot to generate a speed instruction value, and a speed for inputting the speed instruction value and the velocity feedback value to generate a current instruction value. A controller, a current controller that adjusts the voltage applied to the motor by inputting the current command value and current feedback value, and the movement command value that is required to stop the robot when an emergency stop signal is input from the outside. A control device for an industrial robot, comprising: a movement amount command value setting device for setting a minimum value.