JPH04201082A - Control unit for robot - Google Patents

Abstract

PURPOSE:To make a position teachable safely with good efficiency by making the motion speed at the position teaching time variable according to the force quantity pressing a position teaching key switch. CONSTITUTION:When a position teaching key switch 11 is pressed, with the position teaching mode switching switch 10 of a teaching box 9 being pressed, and changed over to a position teaching mode, a position teaching key switch pressing force detection circuit 12 transmits the signal according to the pressed force quantity thereof. The signal thereof is input to a central processing unit 1, to control the speed of the axis to be motioned at the position teaching time. The motion speed at the position teaching time can be controlled linearly and at real time according to the force quantity to press the position teaching key switch 11 with these, and an efficient and safe position teaching becomes possible.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application J] The present invention relates to means for controlling the operating speed of an industrial robot during position teaching.

[Prior Art] Teaching the position of a robot is an essential element in order for the robot to operate accurately, but the operation is simple and safety is important at the same time. As disclosed in Japanese Patent Application Laid-Open No. 62-84993, the conventional technique is to provide a teaching box with a teaching box attachment state detector,
If the teaching pendant is far from the specified installation location, the pulse width of the PWM speed command sent from the central processing unit is limited by an electronic circuit based on the sensor signal of the teaching pendant installation status detector, and the robot operates at a safe speed during teaching. It operates.

[Problems to be Solved by the Invention] The above-mentioned conventional technology suppresses the maximum speed of robot operation in the position teaching mode, and the robot can only move at a preset constant speed during position teaching. Therefore, when approaching the target point of position teaching,
The process of resetting the speed rank and operating it again was inefficient, and the actual speed of the set speed rank could not be confirmed until the robot started moving, which was dangerous.

An object of the present invention is to perform position teaching efficiently and safely by varying the operating speed during position teaching according to the force with which the position teach key switch is pressed.

[Means for Solving the Problems] In order to achieve the above object, the present invention includes means for detecting the amount of force with which a key switch for operating each axis of the position tee is pressed.

[Effect]

When you press the position teaching mode changeover switch on the teaching pendant to switch to position teaching mode and press the position teach key switch, the position teach key switch pressing force detection circuit will detect the position teaching mode according to the pressing force.
send a signal. The signal is input to the central processing unit to control the speed of the axis to be operated during position teaching.

As a result, the operating speed during position teaching can be controlled linearly and in real time according to the amount of force with which the position teach key switch is pressed, allowing efficient and safe position teaching.

[Example] Hereinafter, an example of the present invention will be described with reference to FIGS. 1 to 4.

FIG. 1 is a block diagram of a circuit configuration in a position teaching mode of a robot according to an embodiment of the present invention, and FIG. 2 is an example of a position teaching key switch pressing force detection circuit of an embodiment.
The figure is a configuration diagram of an industrial robot and a robot control device according to an embodiment.

Although only one motor 7 for driving each axis and only one circumferential pulse encoder 8 for each axis are shown in FIGS. 1 and 3, in reality, each axis has a motor and a pulse encoder, and a servo system is configured. This is omitted for the sake of simplicity.

First, the overall configuration of the robot will be explained using FIG.

By operating the keys on the teaching box 9 shown in FIG. 3, position teaching and operation sequence programs are input. The input data is stored in a control circuit in the robot controller t6, and in the test operation mode and continuous operation mode, the robot body 17 is operated in a programmed sequence by pressing the operation key. On the other hand, the robot main body 17 is controlled by the controlled current from the robot control device 16 to move the first arm 18, which is a horizontal movement axis, the second arm 19, and the vertical axis 20. Each drive motor 7 of the twist shaft 2I is controlled and driven. Further, the state of each drive motor 7 is fed back to the robot control device 16 in the form of a pulse signal by a pulse encoder 8, which is a detector for the position and speed of the drive motor attached to each drive motor 7. The robot is controlled and operated using the method described above.

Next, the circuit configuration and operation of the present invention will be explained with reference to FIG. First, the motor servo control system will be explained.

The central processing unit 1 sends a current command for each axis drive motor 7 as a PWM command in order to set the current state to the desired state based on the current position and speed feedback values, and the current command is converted into an analog command by each axis integrator 2. The current is transmitted to each axis current control circuit 3. On the other hand, the current amount of current of each axis drive motor 7 is fed back from each axis motor driver circuit 5 as an analog signal to each axis current control circuit 3, and each axis current control circuit 3 receives an analog command from each axis integrator 2. A differential level signal of the motor current amount signal from each axis motor driver circuit 5 is output, and each axis PWM current command generation circuit 4 generates a PWM I flow command proportional to the differential level signal, and each axis motor driver circuit 5 The motor 7 is operated to control and drive each shaft drive motor 7. Then, the position and speed of each axis drive motor 7 are determined by counting the pulses sent from each axis pulse encoder 8 using each axis pulse counter 6, and feeding that value back to the central processing unit 1 to form a new current command. This constitutes the servo system.

Now, in order to perform position teaching, when the position teaching mode changeover switch IO on the teaching box 9 is pressed, the central processing unit 1 starts controlling the position teaching mode, applies position servo to each axis, and switches the position teaching mode switch IO on the teaching box 9. There is a position teach key switch 11 that operates each axis by position teaching. There are two switches for each axis, and the horizontal drive axis is a right or left switch, and the vertical axis is a switch for up or down.

Next, an explanation will be given using an example in which position teaching is performed by operating the first arm 18. First, when the position teaching mode changeover switch 10 is pressed, the central processing unit 1 starts controlling the position teaching mode and applies position servo to each axis. Next, when the right or left position teach key switch 11 for the first arm 18 is pressed, the position teach key switch depression force detection circuit 12 generates an analog signal proportional to the amount by which the position teach key switch is depressed. This analog signal is input to the A/D converter 13, converted into an 8-bit digital signal, and input to the central processing unit 1. The central processing unit 1 reads the data and uses a speed servo to control the first arm 18 to operate at a speed proportional to the size.

In addition, the central processing unit 1 reads 8-bit data of the amount of pressing force of the position teach key switch 11 output from the A/I converter 13 at a certain period, and changes the speed of the first arm 18 at any time according to the data. It is something. As a result, it is possible to operate the position teach key switch II in a linear manner and in real time, such that if it is pressed hard, it will operate quickly, and if it is pressed weakly, it will operate slowly. Further, the central processing unit 1 places a limit on the maximum value of the PWM command value of each operating axis during the position teaching mode to prevent runaway during position teaching.

Further, the present invention will be explained in detail using the flow diagram shown in FIG. When the position teach mode changeover switch 10 on the teaching box 9 is pressed, the central processing unit 1 puts all the drive axes of the robot into the position servo state, and enters the position teach mode in which the position teach key switch 11 can accept data. Next, the operator starts position teaching and presses the position teach key switch 11 on the teaching box 9.
When pressed, the central processing unit 1 receives and detects the pressing force of the position teach key switch as 8-bit data through the position teach key switch pressing force detection circuit 12 and the analog-to-digital converter 13. A PWM current command proportional to the 8-bit data drives the motor 7 of the drive shaft corresponding to the position teach key switch that is fully pressed.

Further, the position teach key switch pressing force lateral ratio is determined at a certain fixed period, and a PWM current command proportional to the data is transmitted at any time.

Next, an example of the position teach key switch pressing force detection circuit 12 will be explained using FIG. A metal plate 22 serving as a conductor is attached to the position teach key switch 11, and a spring 1 is attached to the position teach key switch 11.
Push it up at 5. On the other hand, the metal plate 22 is kept in contact with the resistor 14 and connected to GND on the circuit.

A current suppression resistor 23 is installed in series with the resistor 14.

With the resistor 14 vs. GND as the output, if you apply a DC1i pressure (for example, DC12V') to the current suppression resistor 23 vs. GND, and press the position teach key switch, there is a resistance of resistor I4 corresponding to the amount of push. , the voltage at the output section also changes accordingly. This detects the amount of push-in.

[Effects of the Invention] According to the present invention, the operating speed of position teaching can be controlled linearly and in real time while pressing the position teach key switch, so position teaching can be performed efficiently and safely.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a position teaching mode according to an embodiment of the present invention, FIG. 2 is a block diagram of a position teaching key switch pressing force detection circuit according to the embodiment, and FIG. 3 is a block diagram of an industrial robot and a position teaching mode according to the embodiment. FIG. 4, which is a perspective view of the robot control device, is a flowchart showing the operation of the embodiment of the present invention. 1... Central processing unit, 2 - Each axis integrator. 3...Each axis current control circuit. 4...Each axis PWMii style command generation circuit. 5...Each axis motor driver circuit. 6... Pulse counter for each axis, 7... Drive motor for each axis. 8... Pulse encoder for each axis. 9...Teaching box. 10...Position teach mode changeover switch. 11...Position teach key switch. 12...Position teach key switch pressing force detection circuit. 13...Analog-digital converter. 14...Resistance L 15...Spring, 16...Robo・
Soto control device. 17...Robot body, 18...First arm. 19...Second arm, 20...Vertical axis, 21...
twist axis. 22... Metal plate, 23... Current suppression resistor. Senior 12? Sword No. 3 Quotation 4

Claims (1)

[Claims] 1. In an industrial robot equipped with position and speed servo mechanisms for operating axes, a position teach key switch on a teaching box that operates each axis during position teaching, and the position teach key thereof. It is equipped with a position teach key switch pressing force detection means that generates a signal according to the amount of force with which the switch is pressed, and is characterized by the fact that in the position teach mode, the operation speed during position teaching is variable according to the amount of force with which the position teach key switch is pressed. A robot control device.