JPH08309682A - Industrial robot - Google Patents

Abstract

PURPOSE: To neglect a delay time of transmitting stop timing by providing a sensor of detecting a floating amount of a floating mechanism, and providing an NC part of directly fetching this detection signal to instantaneously decelerate and stop a motor by a minimum moving amount in a deceleration curve preset for sudden stopping. CONSTITUTION: When any abnormality is generated to apply more than necessary external force vertically in an upward direction against a tool 11 of a robot hand part, a floating mechanism of absorbing this force is operated, to move the tool 11 itself relatively in an upper direction relating to a flange 12. A relatively moved amount of the tool 11 is detected by a sensor 13, and in the point of time influenced to an external force absorbing limit of the floating mechanism, of this fact, an NC part 16 of a controller 14 is directly informed through a stop command exclusive use input 17. The NC part 16, which receives a detection signal of the sensor 13, instantaneously starts deceleration stop processing a motor. A deceleration curve here used is a deceleration curve made tuning so as to be braked by full power of the motor.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an industrial robot attached to a robot hand portion and having a function of stopping suddenly for the purpose of protecting a tool or a work object when an abnormality occurs during operation.

[0002]

2. Description of the Related Art In recent years, industrial robots have become smaller and thinner with the downsizing of production equipment and objects, and their strength tends to decrease. Increasingly, the tool protection function at the time of abnormality is emphasized.

A conventional industrial robot will be described below. FIG. 3 shows an example of a tool protection stopping means in a conventional industrial robot. In FIG. 3, 1 is a tool of a robot hand part, 2 is a flange having a floating mechanism that absorbs an external force applied in the vertical direction of the tool 1, 3 is a sensor for detecting the floating amount in the flange 2, and 4 is a sequencer. , Hereinafter referred to as PLC. Reference numeral 5 is a general-purpose input unit of the PLC 4, 6 is a robot controller, and 7 is a general-purpose output unit of the PLC 4, which is an interface unit that gives an instruction to stop the operation to the robot controller 6. In the robot controller 6, 8 is an NC unit that controls motion control of the robot, and 9 is a main processing unit that controls robot language execution processing, input / output signal control, monitoring processing of the NC section, and the like.

With respect to the industrial robot having the above-mentioned components, the tool protection stopping operation will be described below. First, while the robot's vertical axis is moving downwards,
When some abnormality occurs and an excessive external force is applied vertically upward to the tool 1 of the robot hand, a floating mechanism that absorbs the external force acts, and the tool 1 itself moves upward relative to the flange 2. Move to. When the relative movement amount of the tool 1 is detected by the sensor 3 and the external force absorption limit of the floating mechanism is reached, the fact is detected by the PLC 4
To the general input unit 5. Upon receiving the detection signal of the sensor 3, the PLC 4 shifts to the abnormal condition processing, instructs the main processing unit 9 of the robot controller 6 to stop the operation via the interface unit 7, and receives the main signal of the robot controller 6 of the robot controller 6. The processing unit 9 entrusts the NC unit 8 with control of the robot and decelerates and stops the vertical axis movement.

[0005]

However, in the above-mentioned conventional configuration, the NC unit 8 actually stops the motor when the stop timing occurs due to the delay due to the scan time of the PLC 4 and the overhead time due to the NC monitoring cycle of the robot controller 6. There is a delay time of the order of 1/10 second before the start of, and from that point onward, a considerable amount of movement is performed to stop the normal deceleration and stop. There is a problem that the work object is damaged.

The present invention solves the above-mentioned conventional problems, and provides an industrial robot having means for decelerating and stopping with a minimum delay time from the occurrence of a stop timing and with a minimum movement amount of a motor. With the goal.

[0007]

To achieve this object, an industrial robot according to the present invention comprises a tool of a robot hand, a flange having a floating mechanism for absorbing an external force in the vertical direction, and a floating mechanism of the floating mechanism. A sensor that detects the floating amount, an NC section that directly fetches the detection signal and immediately decelerates and stops the motor with a minimum movement amount according to a deceleration curve that is set for abrupt stop in advance. It has a controller configuration having means for notifying a multi-task control unit that controls the control other than NC, means for executing abnormal time processing by the notification, and means for selecting whether or not to have these overall functions. There is.

[0008]

With this configuration, the stop timing can be directly changed to NC.
Since the parts can be monitored, the delay time can be ignored and the processing with the braking priority of the motor is performed. In addition to the normal operation deceleration curve, a deceleration curve table that has been tuned in advance for braking with full motor power considering the inertia of the robot arm for sudden stop
By preparing in the C section, deceleration and stop can be performed with priority given to minimizing the movement amount required for deceleration. Further, since the occurrence of the sudden stop is notified to the multitask control unit with a slight delay, the system can be operated consistently.

[0009]

An embodiment of the present invention will be described below with reference to the drawings. As shown in FIG.
Is a tool of the robot hand portion, 12 is a flange having a floating mechanism that absorbs an external force applied to the tool 11 in the vertical direction, 13 is a sensor that detects the floating amount in the flange 12, and 14 is a controller. Is a multi-task control unit that manages the operation management of the entire equipment, operation system, sequence of robot operation, other actuator operation control, control other than NC such as abnormal processing, 16 is a deceleration curve preset for sudden stop , An NC unit for decelerating and stopping with the minimum movement amount of the motor, 17 is an input unit dedicated to a stop command in which the NC unit 16 receives a detection signal of the sensor 13, and 18 is an NC unit
6 notifies the multitask control unit 15 of the occurrence of the sudden stop, and the multitask control unit 15 to the NC unit 16
It is a 2-port memory for interface for instructing to enable / disable this function.

The operation of the tool protection stop in the industrial robot having the above-mentioned components will be described with reference to FIG. In FIG. 2, (a) shows the raised position of the tool 21, and (b) shows the lowered position of the tool 21.
Here, as shown in FIG. 6C, when the robot vertical axis moves downward, some abnormality occurs, and when an external force more than necessary is applied vertically upward to the tool 11 of the robot hand, The floating mechanism that absorbs
The tool 11 itself moves relatively upward with respect to the flange 12. When the relative movement amount of the tool 11 is detected by the sensor 13 and the external force absorption limit of the floating mechanism is reached, the N of the controller 14 shown in FIG.
The C section 16 is directly notified via the stop command dedicated input 17. Upon receiving the detection signal of the sensor 13, the NC unit 16 immediately starts the deceleration stop process of the motor. In addition to the normal deceleration curve, the deceleration curve used at this time is a deceleration curve that has been tuned in advance so that the inertia of the robot arm is taken into consideration so that braking can be applied with the full power of the motor. Decelerate and stop with priority on minimizing the amount. The completion of the sudden stop after the motor is stopped is notified from the NC unit 16 to the multitask control unit 15 via the interface 2-port memory 18.
Will be notified to. Multitask control unit 1 that received the notification
5 shifts to abnormal time processing, moves the vertical axis of the robot upward to the safe position, retracts the tool 11, and then displays an abnormal warning. Further, when it is not desired to inadvertently shift to abnormal processing during the robot position teaching work, etc., the multitask control unit 15 causes the NC unit 16 to execute the overall operation of these through the interface 2-port memory 18. This can be done by instructing to disable the function.

In the present embodiment, the interface 18 between the multi-task control unit 15 and the NC unit 16 is a two-port memory, but it goes without saying that it may be an independent DIO.

[0012]

As is apparent from the above description of the embodiments, the present invention provides an industrial robot with a tool for a robot hand, a flange having a floating mechanism for absorbing an external force in the vertical direction, and the floating mechanism. A sensor that detects the floating amount, an NC unit that directly fetches the detection signal and immediately decelerates and stops the motor with a minimum movement amount according to a preset deceleration curve for sudden stop. After the motor is stopped, the result and state are NC. Other than the above, the controller is provided with means for notifying the multi-task control section that controls the control, means for executing abnormal time processing by the notification, and means for selecting whether or not these overall functions are provided. By this, the motor braking priority processing that can ignore the transmission delay time of the stop timing is performed, and the movement amount required for deceleration is minimized. Deceleration stop is possible was. Further, since the occurrence of the sudden stop is notified to the multitask control unit with a slight delay, it is possible to realize an excellent industrial robot capable of consistent operation as a system.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an industrial robot according to an embodiment of the present invention.

FIG. 2 is a functional explanatory diagram for explaining a sudden stop operation of the industrial robot.

FIG. 3 is a functional explanatory diagram for explaining a sudden stop operation of a conventional industrial robot.

[Explanation of symbols]

 11 Tool 12 Flange with Floating Function 13 Sensor for Floating Amount Detection 14 Controller 15 Multi-task Control Section 16 NC Section 17 Stop Command Dedicated Input Section 18 Interface 2 Port Memory

Claims (1)

[Claims] 1. A tool of a robot hand, a flange having a floating mechanism that absorbs an external force in the vertical direction, a sensor that detects the floating amount of the floating mechanism, and a detection signal that is directly taken in and immediately taken in advance. The NC unit that decelerates and stops the motor with the minimum movement amount according to the deceleration curve set for stop, the means for notifying the result or state to the multitask control unit that controls the control other than NC after stopping the motor, and the notification An industrial robot equipped with a controller that has means for executing abnormal time processing and means for selecting whether or not these overall functions are present.