JPS58214913A - Monitor device for fault of robot speed control signal - Google Patents

Abstract

PURPOSE:To avoid giving evil effects to an operator and peripheral devices due to a high-speed of a robot shaft which is caused by the runaway of a motor, by using a position control circuit, etc. which receives a shift command given from a software and delivers a speed command. CONSTITUTION:A position control circuit, etc. receives a shift command given from a software and delivers a speed command. For instance, a shift command given from a software is fed to an adder 15 and stored in an error register 12 after calculating the difference to a feedback pulse signal. The contents of the register 12 receive a D/A conversion through a D/A converter 13 and are fed to an LPF2. The output of the LPF2 is supplied to a speed control unit 4 to drive a motor 5 via an operational amplifier, etc. Then a pulse coder 51 generates a pulse signal and supplies it to a phase discriminating circuit 14. The output signal of the circuit 14 is converted into a speed feedback signal via an adder 15 and an F/V converter 3 and supplied to the unit 4 and a speed command is supplied to a comparator 8 via an absolute value circuit 6.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an abnormality monitoring device for robot speed control signals.

An outline of the configuration of a conventional robot drive device is shown in FIG. Movement command FiV by software! , position control circuit IK, added, adder 15, error.

-Register 12, Digital-Analog (1) A)
Via the converter 13 and the low-pass filter 2, it is fed as a speed command to one input terminal of the speed control unit 40.

The speed control unit node 4 that receives the speed command drives the electric motor 5 for controlling the robot.

A pulse coder 51 connected to the electric motor 5 generates a pulse signal in response to the rotation of the electric motor 5, and the pulse signal is sent to the frequency-voltage (F-V) converter 3 via the phase discrimination circuit 14 in the position control circuit 1. Supplied. The F-V converted pulse signal is supplied to another input terminal of the speed control unit 4 as a speed feedback signal.

In the above-mentioned device, if an incorrect movement command is received or if the speed command becomes an abnormal value due to a defect in each element in the position control circuit 1, the electric motor goes out of control and one robot's axis moves at high speed. There was a problem that it caused harm to the operator or peripheral equipment. Manen Pulsecoder 51,
A similar problem occurs when the speed feedback signal becomes an abnormal value due to a defect in the phase discrimination circuit 14 or the 1iF4 converter 34.

SUMMARY OF THE INVENTION In view of the above-mentioned problems in conventional devices, it is an object of the present invention to compare a speed summer command signal or a speed feedback signal with a set value, and to issue a warning when t' exceeds a set value. Based on the concept of stopping the robot when the robot is stopped, the electric motor may run out of control if a movement command by software gives a specific signal or due to a defect in the elements that make up the device.
This is to prevent the robot axis from moving at one speed and causing harm to the operator or peripheral equipment.

In the present invention, a position control circuit receives a movement command by software and outputs a speed command, a speed control unit receives the speed command, an electric motor receives the output of the speed control unit and controls the robot, and the electric motor A robot speed control signal abnormality monitoring device comprising a frequency-to-electronic converter that converts a feedback pulse signal from a connected pulse coder and returns the converted output to the speed control unit. , at least one absolute positive circuit receiving at least one of the speed 1ψ limit input signals supplied to the speed control unit; The absolute value circuit receives the output having a large angle value directly to the first input 4, and the set type 1 is supplied to the input 11 of the male 2, and the Human power for input terminal 1? The current pressure is the input of the second input 1M, 1. A robot speed system characterized by being fully equipped with a ratio axis device that outputs an abnormality indication and a signal for normal processing when E exceeds A'%.
111 signal abnormality monitoring device is installed.

A circuit diagram showing the configuration of a robot R1 control signal abnormality monitoring device as a first embodiment of the present invention is shown in FIG. In the figure, the reference number r for question 1 is used 11 for the same element as the slot 1 element of the conventional type apparatus in FIG. 1. This device includes a position control circuit l1 position 1ttll which receives a movement command Fi from a software unit (a low-pass filter 2 which receives an output from an i11 circuit, and a low-pass filter 2).
a speed control unit 4 which receives the output of the above at a first input terminal;
an F-Vf converter 3 which receives signals from a pulse coder 51 and a pulse coder 51 connected to an electric motor 5 driven by a speed control unit 4 and an electric motor 5 via a phase discrimination circuit 14 in the position control circuit 1; An absolute value circuit 6 whose input terminal is connected to the first input terminal of the speed 1i control unit 4, a DA converter 9 which receives external digital signals and outputs a corresponding analog Machida signal, and an absolute value circuit. A comparator 8 receives the output of 1) A converter 49 at its non-inverting input terminal, and receives the output of 1) A converter 49 at its inverting input terminal EVc.

The position control circuit IK includes a positive/con gain setting circuit 11,
An error register 12, a DA converter 13, a phase discrimination circuit 14, and a 7JO, M: circuit 15 are included. The absolute 1 circuit 6&i is composed of, for example, operand 1 separators 61 and 64, resistors 62 and 63, and diodes 65 and 66.

Next, the operation of the above-mentioned device will be explained. The difference between the software-based movement command and the feedback pulse signal is calculated in the adder 15, and the result is given to the error register 12. The internal signal of the error register 12 is DA-converted by a DA converter 13 and supplied to the low-pass filter 2. The output of the low-pass filter 2 is applied to a first input terminal of a speed control unit 4, which controls an operational amplifier and the like to drive an electric motor 5. Electric motor 5
The pulse coder 51 connected to generates a pulse signal in response to the rotation of the electric motor 1a5 and supplies it to the phase discrimination circuit 101, and the output of the phase discrimination circuit 14 is sent to the 7Iu calculator 15 and the F-V converter 3. Supplied. The F-V converted signal from the pulse coder 51 is applied as a speed feedback signal to the second input terminal of the speed control unit, and the motor 5 is driven by the difference between the speed command and the speed feedback signal. On the other hand, the speed command is given to the absolute value circuit 6, and is converted into a positive magnetic field that is independent of the rotational direction and proportional to the rotational speed. The setting value (digital value) given by software or an external signal can be switched according to the robot operation, such as high speed or low speed, and is added to the DA converter 90 input as the speed control signal abnormality detection level setting value. The set value converted by the DA converter 9 is compared with the absolute value of the speed command voltage in the comparator 8, and if the absolute value of the speed command voltage exceeds the set value, the comparator 8 also outputs a signal indicating that the speed control signal is abnormal. is output, and can be used to cut off the power supply circuit of the speed control unit 4 or the tl that drives the alarm.

A robot speed control signal abnormality monitoring device as a second embodiment of the present invention is shown in FIG. In this device, the output of the F-V converter is seen at the input of the absolute value circuit 70 for 7 m. The rest is the same as the first embodiment. The seven absolute value circuits have the same configuration as the absolute value circuit 6. As a result, the absolute value of the speed feedback signal voltage is compared with the set value, and if it exceeds the set value, the comparator 8 outputs a signal indicating that the speed control signal is abnormal.

A third embodiment of the invention is shown in FIG. This device has an absolute value circuit 6 and an absolute value circuit 7. A speed command is inputted to the input of the absolute value circuit 6 from the first input terminal of the speed control unit 4, and the speed command is inputted to the input of the absolute value circuit 7 from the first input terminal of the speed control unit 4. The output of the -V converter 3 is input. In addition, if the output of the absolute value circuit 7 has a different pressure value per unit rotational speed between the speed feedback input and the speed feedback input, the level is adjusted by the arithmetic intensifier 81, and the output of the absolute value circuit 6 and the state are adjusted. Zero absolute value circuits 6 and 7 are used to adjust the level per rotational speed.
The outputs from the comparator 8 are mixed at the input terminal of the comparator 8, and the larger of the two outputs is applied to the input terminal of the comparator 8. According to this, when the speed command is set, the signal with the larger absolute value of the speed feedback signal is compared with the set value in the comparator 8, and if the absolute value of the signal exceeds the set value, the speed control signal is abnormal. signal is output.

According to the present invention, if a movement command by software gives an abnormal signal or a defect in an element constituting the device causes the motor to run out of control and the axis of one robot to operate at high speed, causing harm to the operator or peripheral equipment. This can be prevented.

[Brief explanation of the drawing]

Figure 1 is a circuit diagram showing the configuration of a conventional type robot drive device, Figure iA2 is a circuit diagram showing the configuration of a robot speed control signal abnormality monitoring device as the first embodiment of the present invention,
The figure is a circuit diagram showing an embodiment of w42 of the present invention, and FIG. 4 is a circuit diagram showing a third embodiment of the present invention. l...Position control circuit, 2...Low pass filter, 3...F-4 converter, 4...Speed control unit, 5... ...Electric motor, 6.7...
... Absolute value circuit, 8 ... Ratio H device, 9 ...
...DA conversion! , 51...Pulse coder, 81
・・・・・・Operation amplifier. Patent applicant: 1m FANUC residence], Company patent application agent: Akira Yoimoto, patent attorney, Kazuyuki Nishidate, patent attorney: Akira Yamaguchi

Claims (1)

[Claims] A position control circuit that receives a movement command from software and outputs a speed command; a speed control unit that receives the speed command;
The output of the speed control unit is received by an electric motor that controls the robot, and a feedback pulse signal from the connected pulse coder, which converts the frequency and voltage, and returns the converted psychodynamic force to the speed control unit. a frequency-to-voltage converter, at least one absolute value circuit each receiving at least one of the speed control input signals supplied to the speed control unit; The one having the largest voltage value among the outputs of the fallen circuit is received at the first input terminal, and the set voltage is supplied to the second input terminal, and the input voltage of the first input terminal is 1. An abnormality monitoring device for a robot speed control signal, comprising a comparator that outputs an instruction and a signal for abnormality processing when the input voltage of an input terminal is exceeded.