JPH04120408A - Detecting method for movement amount - Google Patents

Abstract

PURPOSE:To obtain a correct movement amount by placing a plurality of pulse generators and taking majority of movement amounts based on outputs of the respective pulse generators to be an output of a signal processing circuit. CONSTITUTION:A robot arm 2 is attached to an end of an output shaft of a motor 1, while rotary encoders 4a to 4c are connected via motion transmission mechanisms 3a to 3c to the other end of the output shaft. Pulse signals obtained from the respective rotary encoders 4a to 4c are sent to counters 6a to 6c in a signal processor 5. These counters 6a to 6c clear counted values after the counted values are sent to a majority circuit 8 by a pulse signal from a timer 7. The majority result of the counted values is output from the circuit 8, and this is a final output 9 from the processor 5. Therefore even if one of the three rotary encoders is defective, a correct value can be obtained as a movement amount.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a method for detecting a motion amount, and in particular to a motion amount detection method using a structure and signal processing for obtaining the amount of rotation and expansion/contraction of a joint of a robot driven by an actuator. Regarding detection method.

[Background Art] Control systems such as robots detect the amount of movement and speed of each actuator in order to control the actuators. Generally, in conventional robots, each actuator is equipped with one pulse generator, and the amount of operation is determined from the accumulation of the number of pulses, and the operation speed is determined from the number of pulses per unit time. The actuator is automatically controlled using only this information. [“Robot Basic Control Wheel” by Tsuneo Yoshikawa
See pages 7 to 9, Corona Publishing (November 1988) 1 [Problem to be solved by the invention] However, the pulse generator is a precision optical component that requires a high level of skill to assemble and is susceptible to vibration and shock. . In other words, reliability is low. For this reason, it may fail during use and pulse generation may stop. As a result, incorrect operating speeds and operating amounts are fed back to the automatic control system, resulting in runaway operation.

An object of the present invention is to obtain correct values of operating quantities such as the amount of rotation and the amount of expansion/contraction using a pulse generator that generally has low reliability. Another object of the present invention is to facilitate identification of failures in the pulse generator and reduce repair time.

[Means to solve the problem]

The above objective is achieved by the following means.

(a) an actuator, a pulse generator that generates a pulse every certain amount of movement of the actuator, and a transmission mechanism that transmits the movement from the actuator to the pulse generator;
A signal processing circuit that processes signals from the pulse generator and outputs an amount of operation, and a method for detecting the amount of operation based on the output from the signal processing circuit, in which a plurality of the pulse generators are installed, and each pulse A method for detecting an amount of operation, characterized in that a majority vote of the amount of operation based on the output of a generator is used as the output of the signal processing circuit.

(b) An actuator, a pulse generator that generates a pulse for every fixed amount of movement of the actuator, a position detector that generates an output proportional to the output position of the actuator, and detection of the pulse generator and the position from the actuator. In the method of detecting the amount of operation based on the output from the signal processing circuit, the method includes a transmission mechanism that transmits the operation to the pulse generator, and a signal processing circuit that processes the signal from the pulse generator and outputs the amount of operation. A method for detecting an amount of operation, characterized in that a plurality of generators and the position detector are installed, and a majority vote of the amount of operation based on the output of each pulse generator and position detector is used as the output of the signal processing circuit. .

[Effect]

According to the above configuration, if less than half of the pulse generators fail, the erroneous operation amount is ignored. Therefore, even if the reliability per pulse generator is not necessarily high,
It becomes possible to obtain the correct amount of motion.

If only two pulse generators and position detectors can be installed in total due to the limited space for installing the pulse generators, it is not possible to make a decision based on majority vote. At this time, the motion amount signals obtained from the outputs of the respective detectors are compared, and if they do not match, a signal indicating the mismatch can be output. If the actuator operation is stopped when a mismatch signal is output, actuator runaway can be prevented.9 Also, in the actuator control system, if the fault is in the pulse generator or position detector Since the problem is identified, the time required for repair is shortened.

Further, even when there are three or more pulse generators and position detectors in total, by outputting a mismatch signal, it is possible to quickly repair a malfunctioning part, and the reliability of operation amount detection can be further improved.

〔Example〕

Hereinafter, some embodiments of the present invention will be described with reference to the drawings.

FIG. 1 shows an example in which a motor is used as an actuator and three rotary encoders are used as pulse generators.

A robot arm 2 is attached to one end of the output of the motor 1. The other end of the output shaft of the motor 1 is connected to a rotary encoder 48 via power transmission mechanisms 38 to 3c.
~4c.

Pulse signals obtained from each rotary encoder 48 to 4c are sent to counters 6a to 6c within the signal processing device S. On the other hand, after the counters 6a to 6c send their count values to the majority circuit 8 by the pulse signal from the timer 7,
Clear the count value. The majority decision circuit 8 outputs the majority decision result of the count value, which becomes the final output 9 from the signal processing device 5.

If the number of rotary encoders is four or more, the number of counters may be increased accordingly. According to this,
Even if one of the three rotary encoders fails,
A correct value can be obtained as the amount of motion.

FIG. 2 shows an example in which a motor is used as an actuator, a potentiometer is used as a position detector, and two rotary encoders are used as pulse generators.

A robot arm 12 is attached to one end of the output of the motor 11. The other end of the output shaft of the motor 11 is
It is connected to a potentiometer 19 and rotary encoders 14a to 14b via power transmission mechanisms 13a to 13c. Pulse signals obtained from each rotary encoder 14a-14b are sent to counter values 16a-16b within the signal processing device 15. On the other hand, the counter 16a~
16b sends the count value to the majority circuit 18 in response to a pulse signal from the timer 17, and then clears the count value.

Similarly, the voltage signal obtained from the potentiometer 19 is sent to the operation amount detection circuit 20 within the signal processing device 15. The operation amount detection circuit 20 sends the operation amount to the majority decision circuit 18 using a pulse signal from the timer 17, and then clears the inside. From the majority circuit 18, the counter 16 a ”
A majority vote result of the count value from 16b and the motion amount signal from the motion amount detection circuit 20 is output, and this becomes the final output 21 from the signal processing device 15.

According to this, even if one of the rotary encoder and the potentiometer fails, a correct value can be obtained as the amount of operation.

Furthermore, in FIG. 1 or 2, the counter 6.16
It is also conceivable to add a function of outputting a mismatch signal from the majority decision circuit 8 when the respective count values from the operation amount detection circuit 20 and the operation amount signal from the operation amount detection circuit 20 do not match.

Generally, the motors 1 and 11, the power transmission mechanisms 3 and 13, the counters 6 and 16, and the potentiometer 19 are parts that are difficult to fail, so the failure location is the rotary encoder 4,
14, which makes it easier to identify and repair the failure location.

FIG. 3 shows an example in which a motor is used as an actuator and two rotary encoders are used as pulse generators.

A robot arm 32 is attached to one end of the output of the motor 31. The other end of the output shaft of the motor 31 is
It is connected to rotary encoders 34a to 34b via power transmission mechanisms 33a to 33b. The pulse signals obtained from each rotary encoder 34a to 34b are
The signals are sent to counters 36a to 36b within the signal processing device 35. - On the other hand, the counters 36a to 36b send their count values to the comparator circuit 38 in response to a pulse signal from the timer 37, and then clear the count values. Comparison circuit 38 compares the two count values and outputs a mismatch signal if they do not match.

Eventually, the signal processing device 35 outputs the count value comparison result 39 and one of the count values 40. By stopping the actuator when a mismatch signal is output, it is possible to prevent the actuator from running out of control even if one of the two rotary encoders breaks down.

In addition, generally a motor 31, a power transmission mechanism 33, a counter 3
Since 6 is a component that is unlikely to fail, it is very likely that the rotary encoders 34a to 34b are the failure location, making it easy to identify and repair the failure location.

FIG. 4 shows an example in which a motor is used as an actuator, a potentiometer is used as a position detector, and a rotary encoder is used as a pulse generator.

A robot arm 42 is attached to one end of the output of the motor 41. The other end of the output shaft of the motor 41 is
Rotary encoder 4 via power transmission mechanism 43a
Connected to 4. The pulse signal obtained from the rotary encoder 44 is sent to the counter 4 in the signal processing device 45.
Sent to 6.

On the other hand, the counter 46 sends the count value to the comparison circuit 48 by the pulse signal from the timer 47.

Clear the count value.

Similarly, the voltage signal obtained from potentiometer 49 is sent to operation amount detection circuit 50 within signal processing device 45 . The operation amount detection circuit 50 sends the operation amount to the comparison circuit 48 in response to a pulse signal from the timer 47, and then clears the inside. The comparison circuit 48 compares the count value from the counter 46 and the operation amount signal from the operation detection circuit 5o, and outputs a mismatch signal if they do not match.

In the end, the signal processing device 45 outputs a comparison result 51 and a count value 52. By stopping the actuator when a mismatch signal is output, it is possible to prevent the actuator from running out of control even if the rotary encoder fails.

Generally, a motor 41, a power transmission mechanism 43, a counter value 46. Since the potentiometer 49 is a component that is difficult to break down, it is very likely that the rotary encoder 44 is the faulty part, making it easy to identify and repair the faulty part.

〔Effect of the invention〕

As described above, according to the present invention, even if the reliability of the pulse generator is low, it is possible to obtain correct values of operating quantities such as the amount of rotation and the amount of expansion and contraction, and runaway of the actuator can be prevented.

Further, by outputting a mismatch signal when the operation amount outputs based on the outputs of the respective pulse generators and position detectors do not match, a failure of the pulse generator can be detected, and the location of the failure can be easily identified and repaired.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a first embodiment of the present invention;
FIG. 3 is a block diagram showing the second embodiment, FIG. 3 is a block diagram showing the third embodiment, and FIG. 4 is a block diagram showing the fourth embodiment. 1.11. ]l, 11...Motor. 4.14,34,44... rotary encoder, 5
．． 15, 35, 45... signal processing device. 6.16, 36, 46... counter. 8.18...Majority circuit, 19.49...Potentiometer, 20.50...Movement amount detection circuit, 38.48...Comparison circuit 6 - Motor 6α to 6c Run 9 4a to 4c... Rotary Encoder 5...Signal pickpocket! ! Device 9...Output 11...Motor +Sa~16b...Counter 14a-14b...Rotary encoder 15-Signal processing Device 19...Button number 9 20...Operation amount detection colloquial language 21...Output diagram 31 ・Tanabata 32・ Lohot Arm 33Q-'33b ・ Moving Kai! m34α~34
b-...○-Tally encoder 35, ff1 processing capacity 360-36b, counter 37, timer 38...Jt soft 11 each 39...engine rA introduction 40...county direct

Claims (1)

[Scope of Claims] 1. An actuator, a pulse generator that generates a pulse every time the actuator moves a certain amount, a transmission mechanism that transmits the operation from the actuator to the pulse generator, and a signal from the pulse generator. and a signal processing circuit that processes the signal and outputs the amount of operation, and the method detects the amount of operation based on the output from the signal processing circuit, wherein a plurality of the pulse generators are installed, and the operation is performed based on the output of each pulse generator. A method for detecting an amount of operation, characterized in that the output of the signal processing circuit is based on a majority vote of the amount. 2. The method according to claim 1, wherein three or more of the pulse generators are installed, and a majority vote based on the output of each pulse generator is used as the output of the signal processing circuit. 3. The operation amount detection method according to claim 1, wherein when the operation amounts based on the outputs of the respective pulse generators do not match, a signal indicating the discrepancy is output. 4. an actuator, a pulse generator that generates a pulse for every fixed amount of movement of the actuator, and a position detector that generates an output proportional to the output position of the actuator;
It consists of a transmission mechanism that transmits the operation from the actuator to the pulse generator and the position detector, and a signal processing circuit that processes the signal from the pulse generator and outputs the amount of operation,
In the method of detecting the amount of operation based on the output from the signal processing circuit, a plurality of the pulse generators and the position detectors are installed, and a majority decision is made on the amount of operation based on the output of each pulse generator and position detector. A motion amount detection method characterized in that the output of the signal processing circuit is set as the output of the signal processing circuit. 5. The method according to claim 4, wherein a total of three or more of the pulse generators and the position detectors are installed, and the signal processing is performed based on a majority vote of the operation amount based on the output of each pulse generator and position detector. A method for detecting the amount of movement used as the output of the circuit. 6. The method according to claim 4, wherein when the motion amounts based on the outputs of the respective pulse generators and the position detectors do not match, a signal indicating the mismatch is outputted.