TW202107858A - Encoder system, motor system and robot - Google Patents

Abstract

A system in which a power supply voltage is supplied from a common power supply circuit to a plurality of encoders is configured such that a fault location in power supply wiring can be easily identified. The system is provided with: an encoder power supply circuit 12 for generating a power supply voltage; individual power supply wires 54 each provided for each encoder 52 to supply the power supply voltage and having one end connected to the encoder; switches 22 each provided for each individual power supply wire 54 on the other end side of the individual power supply wire 54 to switch between connection to and disconnection from the encoder power supply circuit 12; and voltage detection circuits 23 each provided for each individual power supply wire 54 and disposed closer to the encoder 52 than the switch 22 at the other end side of the individual power supply wire.

Description

Encoder system, motor system and robot

The present invention relates to an encoder system including an encoder used for position detection in a robot or the like driven by a motor, a motor system including the encoder system, and a robot.

A robot including a manipulator and a controller is driven by a motor provided for each axis of the manipulator, and the motor of each axis is controlled by the controller based on the position of the axis. To detect the position of each axis, an encoder is used. If the encoder does not operate normally, the manipulator provided with the encoder cannot be operated normally. The encoder is connected to the rotation shaft of the motor of the shaft for each shaft of the manipulator, and detects the rotation position of the motor. The encoder includes an electronic circuit and the like inside, and is supplied with a power supply voltage to output a signal indicating the position of the axis and the like to the control device of the robot. Therefore, the encoder is connected with wiring for power supply, that is, power wiring and signal wiring for transmitting signals. In a manipulator, multiple shafts and multiple encoders are usually installed, but generally, the power supply voltage is supplied to multiple encoders in a form of branching from a common wiring. In addition, as the encoder installed in the manipulator, an absolute encoder is generally used. When the supply of external power supply voltage is stopped, the absolute encoder needs to shift to a backup mode, etc., to retain data, and to perform minimal operations such as storing changes in the rotational position during the stop period.

Among recent robots such as robots that transport glass substrates used in the manufacture of liquid crystal display panels, there are robots that have a large manipulator and a long axis of movement. As the manipulator operates, the position of the encoder in the three-dimensional space changes, that is, the encoder also moves. Therefore, the wiring cable installed in the manipulator and connected to the encoder will also move and be bent or twisted. The bending or twisting of the wiring is referred to as wiring deformation. As a result of the deformation of the wiring, a short circuit or grounding may occur in the wiring in the cable. When the wiring connected to the encoder fails in the signal wiring, the original signal wiring is set for each axis to send position data, so even if there is a failure, the failure will also be regarded as a communication abnormality for each axis Is detected, and the shaft with a bad condition can be easily identified. In contrast, in the case of a power wiring failure, the power supply of all encoders becomes abnormal at the same time due to the common wiring, and it is difficult to determine which axis power wiring has occurred based on the information of the axis where the power supply is abnormal. Fault. Therefore, it is necessary to visually investigate all the power supply wiring installed in the robot, and in the case of a large robot, it takes a lot of time to identify the faulty location. The problem that requires a lot of time to determine the fault location is not a problem inherent to robots, and it is also common in an encoder system with multiple encoders, and a motor system that includes multiple motors and is equipped with an encoder for each motor. Subject.

As an example of a technique for determining the cause of a malfunction associated with an encoder, Patent Document 1 discloses an encoder including: an abnormality detection unit that detects abnormality based on state information related to the state of the encoder or motor; and a cause analysis unit , When an abnormality is detected, analyze the cause of the abnormality based on the status information; and the non-volatile memory control unit stores the analysis result analyzed by the cause analysis unit in the non-volatile memory. As a technique for coping with insufficient power supply to the encoder from the controller side, Patent Document 2 discloses that an auxiliary power supply is provided for each encoder, and a power supply voltage detection circuit is provided, and the power supply voltage detection circuit is supplied from the controller side When the value of the power supply voltage is below the threshold value, the power from the auxiliary power supply is supplied to the encoder. However, the techniques disclosed in Patent Document 1 and Patent Document 2 cannot be used to identify the faulty part of the power supply wiring connected to the encoder. Although it is not associated with an encoder, as a technique for detecting a decrease in power supply voltage and identifying a fault location, Patent Document 3 discloses that when the power supply voltage is supplied to a plurality of external devices from a common power supply, the common power supply is Each power line branched by an external device is provided with a connection/disconnection circuit. When the voltage drop of the common power supply is detected, the power line is sequentially disconnected from the common power supply for each power line, thereby detecting the Which external device has a fault in the corresponding power cord. [Prior Art Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2015-90307 [Patent Document 2] Japanese Patent Laid-Open No. 8-251817 [Patent Document 3] Japanese Patent Laid-Open No. 10-203740

[The problem to be solved by the invention]

In the technique disclosed in Patent Document 3, if the fault is a complete grounding or short-circuit, it can be detected that the power line corresponding to which external device has the fault has occurred, but when it is applied to the detection of a fault in the power wiring of an encoder , It is not sufficient to distinguish the fault of power wiring from the fault of signal wiring or to discover the signs before the failure.

The object of the present invention is to provide an encoder system that can easily identify a faulty part of the power supply wiring corresponding to the encoder, a motor system including such an encoder system, and a robot. [Means to solve the problem]

The encoder system of the present invention has: a plurality of encoders; an encoder power supply circuit that generates a power supply voltage; individual power supply wiring is provided for each encoder for supplying the power supply voltage, and one end is connected to the encoder; a switch, For each individual power supply wiring, it is provided on the other end side of the individual power supply wiring to switch the connection and disconnection of the encoder power supply circuit; and the first voltage detection circuit is connected to the individual power supply for each individual power supply wiring. The other end of the wiring is located closer to the encoder side than the switch.

In the encoder system of the present invention, individual power wiring can be independently connected to or disconnected from the encoder power circuit one by one by a switch, and the voltage can be measured for each individual power wiring, so in the individual power wiring When a fault such as grounding or short-circuit occurs, it can be quickly determined which individual power wiring is faulty, and can be determined from the fault classification of signal wiring, etc., so that the defective part can be identified in a short time.

In the encoder system of the present invention, it is preferable that the first voltage detection circuit output a voltage value, and the encoder is provided with a second voltage detection circuit that detects the supplied power supply voltage and outputs it as the voltage value. According to the above configuration, the voltage drop or wiring impedance (impedance) in individual power wiring can be calculated based on the difference between the voltage value detected by the first voltage detection circuit and the voltage value detected by the second voltage detection circuit, and Easily find abnormalities or pre-abnormal signs in individual power wiring. When the encoder has a function of shifting to the standby mode by detecting a voltage drop, the shift to the standby mode in the event of an abnormality can be easily performed.

When a second voltage detection circuit is provided in the encoder, an arithmetic mechanism may be provided for calculating the difference between the voltage value detected by the first voltage detection circuit and the voltage value detected by the second voltage detection circuit. difference. By calculating the difference in the arithmetic mechanism, the voltage drop or wiring impedance can be automatically calculated, making it easier to find abnormalities or signs before the abnormalities. The arithmetic mechanism can also output the power control signal corresponding to the difference to the encoder power circuit. By sending the power supply control signal to the encoder power supply circuit, the power supply voltage supplied to the encoder can be maintained at an appropriate value even if the voltage drop or wiring impedance changes.

In the present invention, a plurality of encoders may be classified into a plurality of systems according to the length of individual power supply wiring, and an encoder power supply circuit may be provided for each system. If the length of the individual power wiring is different, the voltage drop is also different. Therefore, it is classified into multiple systems based on the length of the individual power wiring. An encoder power supply circuit is provided for each system to predict the voltage drop to set the encoder power supply. The output voltage of the circuit can thereby bring the value of the power supply voltage actually supplied to each encoder closer to an appropriate value.

The motor system of the present invention includes a plurality of motors, and the motor system includes the encoder system of the present invention, and an encoder of the encoder system is provided for each motor. According to the motor system of the present invention, by including the encoder system of the present invention, when a fault such as grounding or short circuit occurs in the individual power wiring provided for each encoder, it is possible to quickly determine which individual power wiring is faulty , So that the defective part can be identified in a short time.

The robot of the present invention has: a manipulator including a plurality of motors; and a controller to control the manipulator, and the robot includes the encoder system of the present invention, and an encoder of the encoder system is provided for each motor. According to the robot of the present invention, when a fault such as grounding or short-circuit occurs in the individual power wiring provided for each encoder, it can be quickly determined which individual power wiring is faulty, so that the defective part can be repaired in a short time. determine.

In particular, in the robot of the present invention, it is preferable that the interval between the first voltage detection circuit and the encoder of each individual power supply wiring includes the deformation of the individual power supply wiring accompanying the movement of the manipulator. Interval. In general, a part of the wiring in a robot is deformed with the movement of the manipulator, and faults such as a short circuit of the wiring, grounding, and disconnection are likely to occur in such a deformed section. Therefore, in the individual power wiring, the section of deformation caused by the movement of the manipulator is included in the section between the switch provided on the other end and the first voltage detection circuit and the encoder on the one end. It is expected that the occurrence frequency of the failure is high, and the location of the occurrence of the failure is determined in a short time, so that the downtime of the robot can be greatly reduced.

In the robot of the present invention, the switch and the first voltage detection circuit can be configured in the controller. By being arranged in the controller, the present invention can be applied to existing robots without modifying the manipulator side. Alternatively, in the robot of the present invention, the switch and the first voltage detection circuit may be configured in the manipulator. If it is placed in a robot, only one power supply wiring related to the encoder can be prepared between the controller and the robot, so the wiring can be easily routed. [Effects of the invention]

According to the present invention, when the power supply voltage is supplied to a plurality of encoders from a shared power supply circuit, the faulty part of the power supply wiring can be easily identified.

Next, a preferred embodiment of the present invention will be described with reference to the drawings. Fig. 1 shows a robot according to one aspect of the present invention. The robot includes a controller 10 and a manipulator 50, and the manipulator 50 includes a plurality of axes. In the manipulator 50, a motor 51 and an encoder 52 mechanically connected to the motor 51 of the shaft are provided for each axis. In the figure, the number of shafts is set to four and four sets of combinations of motors 51 and encoders 52 are drawn, but the number of shafts in the manipulator 50 may also be five or more.

The controller 10 includes: a driver circuit 11, which drives the motor 51 of each axis in the manipulator 50; an encoder power supply circuit 12, which generates a power supply voltage supplied to the encoder 52 of each axis; and an encoder receiving circuit 13, which encodes each axis The device 52 receives a signal indicating the position of the motor and the like; and the control unit 14 is constituted by a microprocessor or the like, and executes calculations and the like necessary for controlling the entire robot. In the drawings, for convenience of explanation, the wiring related to the control unit 14 is indicated by a broken line. The motor 51 of each axis is connected to the driver circuit 11 by the motor wiring 53 provided for each motor 51, and is independently driven by the driver circuit 11 for each axis. In order to supply the power supply voltage to the encoder 52 of each axis, an individual power supply wiring 54 is provided for each encoder 52 at least in the robot 50. The individual power wiring 54 also extends into the controller 10. On the other hand, the self-encoder power supply circuit 12 outputs a power supply voltage via the common power supply wiring 21. In the controller 10, an individual power supply wiring 54 for each axis is connected to the common power supply wiring 21 via a switch 22 for each axis. In addition, the controller 10 is provided with a voltage detection circuit 23 that is connected to the corresponding individual power supply wiring 54 and detects voltage for each individual power supply wiring 54. Although the position where the voltage detection circuit 23 is installed in the individual power wiring 54 is close to the switch 22, it is closer to the encoder 52 side than the switch 22. Therefore, one end of the individual power supply wiring 54 is connected to the encoder 52, and a switch 22 and a voltage detection circuit 23 are provided on the other end side. In the robot, the power supply voltage of the encoder 52 for each axis is shared from the common power supply wiring 21 of the encoder 52, and is connected to the switch 22 and the individual power supply wiring 54 provided for each encoder 52. supply. The switch 22 is connected to and disconnected from the encoder power circuit 12 for each encoder 52.

The signal from the encoder 52 of each axis is input to the encoder receiving circuit 13 via the signal wiring 55 provided for each encoder 52. The controller 10 is also provided with a disconnection detection circuit 15 which detects the disconnection of the signal wiring 55 by detecting the signal voltage of each signal wiring 55 and the like. The control unit 14 executes, for example, the following control: based on the position command input from the outside and the position data input from each encoder 52, the position of the manipulator 50 becomes the position specified by the position command and drives each of them via the driver circuit 11 The shaft motor 51, in turn, controls the on/off (OFF) of each switch 22 or the encoder power supply circuit 12, based on the input from the disconnection detection circuit 15 or the detection value of each voltage detection circuit 23 to determine whether there is any occurrence Determination of the fault or fault location. In order to enable control from the control unit 14, the switch 22 includes, for example, a mechanical relay (mechanical relay) or a semiconductor switch.

The robot of the present embodiment is, for example, a robot for transporting glass substrates used in the manufacture of liquid crystal display panels and the like, and includes a large-scale robot 50, and the robot 50 has a long moving distance. Therefore, the length of the motor wiring 53, the individual power wiring 54 and the signal wiring 55 in the robot 50 is also as long as several tens of meters (m), for example. As the manipulator 50 operates and moves, the motor wiring 53, the individual power wiring 54 and the signal wiring 55 also move together with the manipulator 50. As a result, the manipulator 50 is bent or twisted or deformed and bears various stresses. This kind of stress may also cause wiring grounding, short circuit, or disconnection.

As shown in FIG. 2, in the existing robot, the common power supply wiring 21 from the encoder power supply circuit 12 extends from the controller 10 to the manipulator 50, and the end of the common power supply wiring 21 is directly connected from each encoder 52 individual power wiring 54. As a result, when a fault such as a ground fault occurs in the individual power supply wiring 54 of any axis, the output of the encoder power supply circuit 12 is interrupted by overcurrent or the output voltage is reduced, and the power supply to all the encoders 52 is stopped. Even when each encoder 52 has a function of detecting an abnormality in the power supply voltage, it cannot be determined from the signal from the encoder 52 which encoder 52 is connected to the individual power supply wiring 54 that a failure has occurred. In order to identify the fault location, all the individual power supply wirings 54 in the manipulator 50 have to be inspected visually. In the case of a robot that transports glass substrates for liquid crystal display panels, the robot hand 50 is enlarged and the robot hand 50 itself is placed in a clean room or under a reduced pressure environment. Therefore, all individual parts in the robot hand 50 are inspected. It takes a lot of time to wire the power supply 54 and make the robot self-repair.

In contrast, in the robot of the present embodiment shown in FIG. 1, the individual power wiring 54 connected to each encoder 52 is slightly connected to the common power wiring 21 connected to the encoder power supply circuit 12. The switch 22 is set biased toward the position of the encoder 52. The switch 22 can be individually turned on/off controlled by the control unit 14 for each individual power supply wiring 54, that is, each encoder 52. Therefore, at a time point immediately after the power supply of the controller 10 is turned on, the switch 22 of each encoder 52 is individually turned on and then turned off for each encoder 52 in sequence. At this time, if the encoder receiving circuit 13 can accurately receive the signal from the encoder 52 corresponding to the turned-on switch 22, it can be determined that the individual power wiring 54 and the signal wiring 55 corresponding to the encoder 52 All are normal. In contrast, when the signal from the encoder 52 corresponding to the turned-on switch 22 cannot be accurately received, it can be determined that at least one of the individual power supply wiring 54 and the signal wiring 55 corresponding to the encoder 52 Otherwise, a fault such as grounding occurs. At this time, if the voltage detection circuit 23 connected to the corresponding individual power supply wiring 54 can accurately detect the power supply voltage, it can be determined that the signal wiring 55 from the corresponding encoder 52 has a fault. Conversely, if only one switch 22 is turned on, and the power supply voltage cannot be detected in the voltage detection circuit 23 provided adjacent to the switch, it can be determined that the occurrence of the power supply is in the individual power supply wiring 54 connected to the switch 22. Ground or short circuit.

In this embodiment, the control unit 14 turns on the switches 22 one by one, so that it can be easily determined which encoder 52 has a fault, or the faulty wiring is the individual power supply wiring 54. As for the signal wiring 55, even if the wiring must be inspected visually, the inspection location can be limited, and the time required to determine the fault location or repair the fault can be greatly shortened.

In this embodiment, the voltage detection circuit 23 may include a voltage comparator circuit that only judges whether the input voltage is normal or abnormal. However, with regard to the voltage detection circuit 23, it is better to output the measured voltage as a voltage value than in the case of outputting a binary signal indicating good or bad. The voltage value mentioned here can be either an analog value or a digital value expressed as multi-valued data by the analog/digital (A/D) conversion function. The voltage detection circuit 23 is a circuit that detects the analog value or the voltage value as a multi-value data. If the encoder 52 is also provided with a circuit for detecting the supplied power voltage, it can be based on the voltage detected by the voltage detection circuit 23 Value and the voltage value detected in the encoder 52, the voltage drop amount in the individual power supply wiring 54 is obtained. In the case of a large manipulator 50, the individual power supply wiring 54 is also long, and the voltage drop of the power supply voltage supplied by the individual power supply wiring 54 cannot be ignored. Since the current consumption in the encoder 52 is known and does not vary significantly, the wiring impedance of the individual power supply wiring 54 can be calculated from the voltage drop of the individual power supply wiring 54 and the current consumption of the encoder 52, so that it is easy to perform Confirmation of maintenance or design margin. By tracking the amount of voltage drop or the change in wiring impedance, it is easy to find abnormalities in the wiring or the signs before the abnormality. The power supply voltage actually measured in the encoder 52 is fed back to the control unit 14, and the control unit 14 controls the encoder power supply circuit 12, so that the actual power supply voltage can be supplied to the encoder independently of the amount of voltage drop of the individual power supply wiring 54 The power supply voltage value of the device 52 is set to an appropriate value. For example, the control unit 14 obtains the difference between the voltage value detected by the voltage detection circuit 23 and the voltage value detected in the encoder 52, and outputs a voltage control signal corresponding to the difference to the encoder power supply circuit 12.

In the case of a large manipulator 50, the length of the motor wiring 53, individual power wiring 54 and signal wiring 55 may be quite different depending on which axis of the manipulator 50 the motor 51 or encoder 52 is. . If the length of the individual power wiring 54 is different, the amount of voltage drop in the individual power wiring 54 is also different, and the power supply voltage actually supplied to the encoder 52 is also different. In the case where the voltage drop amount of the individual power supply wiring 54 is different, the power supply voltage actually supplied to each encoder 52 is different when the power supply voltage is supplied from the same encoder power supply circuit 12 to a plurality of encoders 52. It is also difficult to control the encoder power supply circuit 12 by feeding back the measured value of the power supply voltage as described above, and it is also difficult to perform control such as setting the actual power supply voltage to an appropriate value in all the encoders 52. On the other hand, preparing the encoder power supply circuit 12 corresponding to the number of the encoders 52 and supplying the power supply voltage to the encoder 52 from the encoder power supply circuit 12 one-to-one makes the controller 10 larger than necessary.

The robot of another embodiment of the present invention shown in FIG. 3 is the same robot as the robot shown in FIG. 1, but in order to reduce the inconsistency of the power supply voltage actually supplied to the encoder 52 depending on the length of the individual power supply wiring 54, The length of the individual power supply wiring 54 classifies the plurality of encoders 52 into several systems, and the encoder power supply circuit 12 and the encoder power supply circuit 16 are provided for each system. In the figure, two encoder power supply circuits 12 and 16 are provided. Among the four encoders 52, the two encoders 52 with relatively short lengths of individual power supply wires 54 are supplied with power supply voltage from the encoder power supply circuit 12 For the two encoders 52 with relatively long lengths of individual power supply wirings 54, the power supply voltage is supplied from the encoder power supply circuit 16. The encoder power supply circuit 12 and the encoder power supply circuit 16 can respectively adjust the output voltage under the control from the control unit 14, but basically the output voltage of the encoder power supply circuit has been added to the voltage drop of the individual power supply wiring 54. In this way, regardless of the difference in the length of the individual power supply wiring 54, each encoder 52 can be driven with a power supply voltage closer to an appropriate value. The following situation is the same as the content shown in FIG. 1, namely: a common power supply wiring 21 is provided for each encoder power supply circuit 12 and encoder power supply circuit 16; a plurality of individual power supply wirings 54 are branched from each common power supply wiring 21; A switch 22 and a voltage detection circuit 23 are provided for each individual power supply wiring 54.

In the robot shown in FIG. 3, feedback control of the output voltages of the encoder power supply circuit 12 and the encoder power supply circuit 16 can be independently performed based on the power supply voltage actually supplied to each encoder 52. Although the amount of voltage drop is different, the inconsistency of the voltage actually supplied to each encoder 52 among the four encoders 52 becomes smaller, and the power supply voltage actually supplied to the encoder 52 can be made closer to an appropriate value.

In the robot shown in FIG. 1, the switch 22 and the voltage detection circuit 23 are provided in the controller 10, but the switch 22 and the voltage detection circuit 23 may also be provided in the manipulator 50. The robot of another embodiment shown in FIG. 4 is in the robot shown in FIG. 1, the common power supply wiring 21 is extended to the manipulator 50, and the branch point from the common power supply wiring 21 toward the individual power supply wiring 54 is switched 22 and the voltage detection circuit 23 are provided in the manipulator 50, and further, a control unit 60 that controls the switch 22 and receives the detection result from the voltage detection circuit 23 is provided. The control unit 60 cooperates with the control unit 14 provided in the controller 10 to control the robot. Considering that wiring failures are particularly likely to occur at the locations where the wiring is deformed, in order to detect failures more reliably, it is preferable to install the switch 22 and the voltage detection circuit 23 on the individual power supply wiring 54 where the robot arm The part moved by the movement of 50 is closer to the side of the controller 10. Specifically, it is preferable that the individual power supply wiring 54 be branched from the common power supply wiring 21 and the switch 22 and the voltage detection circuit 23 are provided in the vicinity of the part connected to the controller 10 in the manipulator 50.

The robot based on the present invention has been described above, but the present invention is not limited to robots. If it is an encoder system with multiple encoders, the present invention can be applied to any one. In addition, the present invention can also be applied to a motor system having a plurality of motors and an encoder provided for each motor.

10: Controller 11: Driver circuit 12.16: Encoder power supply circuit 13: Encoder receiving circuit 14, 60: Control Department 15: Disconnection detection circuit 21: Shared power supply wiring 22: switch 23: Voltage detection circuit 50: Manipulator 51: Motor 52: encoder 53: Motor wiring 54: Individual power supply wiring 55: Signal Wiring

Fig. 1 is a block diagram showing an embodiment of the robot according to the present invention. Fig. 2 is a block diagram showing a conventional mode of supplying electric power to an encoder. Fig. 3 is a block diagram showing a robot according to another embodiment. Fig. 4 is a block diagram showing a robot according to another embodiment.

10: Controller

11: Driver circuit

12: Encoder power supply circuit

13: Encoder receiving circuit

14: Control Department

15: Disconnection detection circuit

21: Shared power supply wiring

22: switch

23: Voltage detection circuit

50: Manipulator

51: Motor

52: encoder

53: Motor wiring

54: Individual power supply wiring

55: Signal Wiring

Claims (10)

An encoder system with: Multiple encoders; Encoder power supply circuit to generate power supply voltage; Individual power wiring is provided in each of the encoders in order to supply the power supply voltage, and one end is connected to the encoder; A switch is arranged on the other end side of each of the individual power wirings, and switches the connection and disconnection with the encoder power circuit; and The first voltage detection circuit is arranged at a position closer to the encoder side than the switch on the other end side of each of the individual power supply wires. The encoder system according to claim 1, wherein the first voltage detection circuit outputs a voltage value, and The encoder includes a second voltage detection circuit that detects the supplied power supply voltage and outputs it as a voltage value. The encoder system according to claim 2 has an arithmetic unit that calculates the difference between the voltage value detected by the first voltage detection circuit and the voltage value detected by the second voltage detection circuit. The encoder system according to claim 3, wherein the arithmetic mechanism outputs a power control signal corresponding to the difference to the encoder power circuit. The encoder system according to any one of claim 1 to claim 4, wherein the plurality of encoders are classified into a plurality of systems according to the length of the individual power supply wiring, and each system is provided with the encoder power supply circuit . A motor system includes a plurality of motors, and It includes the encoder system according to any one of claim 1 to claim 5, and each of the motors is provided with the encoder of the encoder system. A robot having a manipulator including a plurality of motors and a controller for controlling the manipulator, and It includes the encoder system according to any one of claim 1 to claim 5, and each of the motors is provided with the encoder of the encoder system. The robot according to claim 7, wherein the interval between the first voltage detection circuit and the encoder of each of the individual power supply wiring includes the individual power supply wiring accompanying the movement of the manipulator Deformation interval. The robot according to claim 7, wherein the switch and the first voltage detection circuit are arranged in the controller. The robot according to claim 7, wherein the switch and the first voltage detection circuit are arranged in the manipulator.

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