KR20210006850A - Industrial robot and control method of industrial robot - Google Patents

Abstract

Provided is an industrial robot which is able to, when it becomes impossible to control based on a detection result of an encoder in some of a plurality of motors driven during an extension/contraction motion of an arm, and an encoder error occurs, which is supposed to be controlled based on a detection result of an encoder in the other motors, and the motor is urgently stopped, suppress the deviation of the trajectory of a hand moving until the arm stops from the trajectory in the design. In the industrial robot, when motors being driven (34 through 36) are urgently stopped because of an encoder error, a first motor is urgently stopped by operating a dynamic brake on the first motor which cannot be controlled based on the detection result of the encoders (37 through 39), and a second motor is urgently stopped by being controlled based on an output signal of a second encoder for the second motor as well as an output signal of the first encoder for the first motor although the second motor can be controlled based on the detection result of the encoders (37 through 39).

Description

Industrial robot and control method of industrial robot {INDUSTRIAL ROBOT AND CONTROL METHOD OF INDUSTRIAL ROBOT}

The present invention relates to a horizontal articulated industrial robot. Further, the present invention relates to a control method of a horizontal articulated industrial robot.

Conventionally, an industrial robot that conveys a glass substrate for a liquid crystal display in a vacuum is known (for example, see Patent Document 1). The industrial robot described in Patent Literature 1 includes two hands on which a glass substrate is mounted, an arm to which the two hands are rotatably connected to the distal end side, and a body portion to which the proximal end side of the arm is rotatably connected. The arm is composed of two arm portions in which each of the two hands is rotatably connected to the distal end side, and a common arm portion rotatably connected to the body portion while the base end sides of the two arm portions are rotatably connected. In addition, this industrial robot has a rotation mechanism having a common arm drive motor for rotating the common arm with respect to the main body, and an arm drive motor for rotating the arm with respect to the common arm while rotating the hand with respect to the arm. It is equipped with a drive mechanism.

In the industrial robot described in Patent Document 1, when the arm is extended and contracted and the glass substrate is transported to a glass substrate manufacturing apparatus or the like, a common arm drive motor and an arm drive motor for rotating one arm are driven. At this time, the arm drive motor for rotating the other arm is stopped. Further, at this time, a common arm drive motor and an arm drive motor for rotating one arm are controlled so that the hand connected to one arm moves linearly in a state in a predetermined direction. Specifically, the common arm drive motor and the arm drive motor are provided with an encoder for detecting the rotational position of the motor, and the detection result of the encoder so that the hand connected to one arm moves linearly in a state in a certain direction. The common arm drive motor and the arm drive motor are controlled based on.

Japanese Patent Publication No. 2018-15839

In the industrial robot described in Patent Document 1, when a predetermined error occurs while the arm is extended and contracted, the common arm drive motor and the arm drive motor based on the detection result of the encoder can be controlled, the industrial robot is emergency stopped. In the case of emergency stop of the common arm drive motor and arm drive motor, generally, the common arm drive motor and the arm drive motor are controlled and emergency stop is made based on the detection result of the encoder. Therefore, in this case, it becomes possible to stop the hand after moving the hand along the design trajectory (that is, after moving the hand linearly) until the arm stops.

On the other hand, for example, it is possible to control the common arm drive motor based on the detection result of the encoder, but an encoder error that makes it impossible to control the arm drive motor based on the detection result of the encoder occurs during the expansion and contraction of the arm. In the case of emergency stop of the robot (that is, the case of emergency stop of the common arm drive motor and arm drive motor), it is not possible to make an emergency stop while controlling the arm drive motor based on the detection result of the encoder. Therefore, the inventors of the present invention make emergency stop while controlling the common arm drive motor based on the detection result of the encoder when the encoder error occurs during the arm extension and contraction operation, and emergency stop the arm drive motor by turning on the dynamic brake. I tried it.

However, since the dynamic brake has almost no effect when the motor is at a low speed, in this case, the trajectory of the hand moving while the arm is stopped is largely deviated from the trajectory of the design (i.e., a linear trajectory). It was found that the stopping position of is greatly deviated from the design trajectory. Therefore, the inventor of the present application attempted to emergency stop the common arm drive motor and arm drive motor by turning off the dynamic brake when the encoder error occurs during the extension and contraction of the arm. In this case, the deviation of the trajectory of the hand moving while the arm stops, from the trajectory of the design is small, and the deviation of the stop position of the hand from the trajectory of the design is small, but exceeds the allowable range. It was found that the trajectory of the hand to be played was deviated.

Therefore, an object of the present invention is in a horizontal articulated industrial robot having a hand and an arm to which the hand is rotatably connected, an encoder in some motors among a plurality of motors driven during the extension and contraction of the arm. When the control based on the detection result of is not possible, and the encoder error in which the control based on the detection result of the encoder is enabled for the remaining motors occurs during the expansion and contraction of the arm and emergency stop of multiple motors, the arm It is to provide an industrial robot capable of suppressing deviation of the trajectory of the hand moving until the stop from the trajectory on the design.

In addition, an object of the present invention is in a horizontal articulated industrial robot having a hand and an arm to which the hand is rotatably connected, an encoder in some motors among a plurality of motors that are driven during the extension and contraction of the arm. When the control based on the detection result of is not possible, and the encoder error in which the control based on the detection result of the encoder is enabled for the remaining motors occurs during the expansion and contraction of the arm and emergency stop of multiple motors, the arm It is to provide a control method for an industrial robot which makes it possible to suppress the deviation of the trajectory of the hand moving until it stops from the trajectory on the design.

In order to solve the above problems, the industrial robot of the present invention, in the horizontal articulated industrial robot, has a hand and at least two arm portions that are rotatably connected to each other, and the hand is rotatably connected to the tip side. And a body portion that is rotatably connected to a base end side of the arm, an arm driving mechanism that expands and contracts the arm horizontally with respect to the body portion, and a control unit that controls an industrial robot. And a plurality of motors for stretching and contracting, and a plurality of encoders for detecting rotational positions of the plurality of motors, each of the plurality of encoders being installed on each of the plurality of motors and being driven during the stretching operation of the arm. An encoder error is referred to as an encoder error when control based on the detection result of the encoder becomes impossible for some of the plurality of motors, and control based on the detection result of the encoder is enabled for the remaining motors. The motor during driving in which control based on the detection result of the encoder is disabled at the time of occurrence is referred to as the first motor, and when an encoder error occurs, the driving motor in which control based on the detection result of the encoder is enabled is removed. 2 If the motor is referred to as a motor, and the encoder installed in the first motor is referred to as the first encoder, and the encoder installed in the second motor is referred to as the second encoder, the control unit generates an encoder error during the expansion and contraction of the arm, When emergency stop of a plurality of motors, a dynamic brake is applied to the first motor to emergency stop the first motor, and the second motor is controlled based on the output signal of the first encoder and the output signal of the second encoder. It is characterized by stopping.

In addition, in order to solve the above problems, the control method of an industrial robot of the present invention includes a hand, an arm rotatably connected to the distal end, and an arm having at least two arm portions that are rotatably connected to each other. The base end side of the body portion is rotatably connected, and an arm driving mechanism that expands and contracts the arm in a horizontal direction with respect to the body portion, and the arm driving mechanism includes a plurality of motors for extending and contracting the arm, and It is equipped with a plurality of encoders for detecting the rotational position, and each of the plurality of encoders is a control method of a horizontal articulated industrial robot installed in each of the plurality of motors, and a plurality of motors are driven while the arm is extended or contracted. An encoder error is referred to as an encoder error when control based on the detection result of the encoder is not possible in some of the motors of the following, and control based on the detection result of the encoder is enabled in the remaining motors. At the time, the motor during driving in which control based on the detection result of the encoder is disabled is referred to as the first motor, and the motor during driving in which control based on the detection result of the encoder when an encoder error occurs is referred to as the second motor. Assuming that the motor is referred to as a motor, and the encoder installed in the first motor is referred to as the first encoder, and the encoder installed in the second motor is referred to as the second encoder, an encoder error occurs during the expansion and contraction operation of the arm, causing multiple motors to When making an emergency stop, a dynamic brake is applied to the first motor to stop the first motor, and to control the second motor based on the output signal of the first encoder and the output signal of the second encoder to make an emergency stop. To do.

In the present invention, when an encoder error occurs during the expansion and contraction of the arm and an emergency stop of a plurality of motors during driving is performed, a dynamic brake is applied to the first motor in which control based on the detection result of the encoder is disabled, and the first motor is stopped. In addition to the emergency stop, the second motor, in which control based on the detection result of the encoder is enabled, is controlled based on the output signal of the first encoder and the output signal of the second encoder, while emergency stop is made. That is, in the present invention, when an encoder error occurs during the expansion and contraction of the arm and emergency stop of a plurality of motors during driving, the second motor is not only the output signal of the second encoder installed in the second motor, but also the first motor. The emergency stop is made while controlling based on the output signal of the first encoder installed in the device.

Therefore, in the present invention, when an encoder error occurs during the expansion and contraction of the arm and emergency stops of a plurality of motors during driving, a dynamic brake is applied and the second motor is decelerated according to the deceleration rate of the first motor. It becomes possible to slow down and stop. Therefore, in the present invention, when an encoder error occurs during the extension and contraction of the arm and an emergency stop of a plurality of motors occurs, the trajectory of the hand moving until the arm stops is deviated from the design trajectory (linear trajectory). It becomes possible to suppress

In the present invention, the industrial robot includes a first hand and a second hand, for example, as a hand, and the arm is an arm portion, a first tip-side arm portion to which the first hand is rotatably connected to the tip side, and , The second end-side arm to which the second hand is rotatably connected to the distal end, and the proximal end of the first distal arm and the proximal end of the second distal arm are rotatably connected to the main body. It has a common arm to be connected, and the arm drive mechanism is a motor, comprising: a common arm drive motor for rotating the common arm with respect to the main body, and a first tip arm for rotating the first tip arm with respect to the common arm A drive motor and a second tip-side arm drive motor for rotating the second tip-side arm with respect to the common arm portion are provided, and when the arm is extended and contracted, the second tip-side arm drive motor is stopped. The second tip-side arm drive motor and the common arm drive motor are driven in a state in which the tip-side arm drive motor and the common arm drive motor are driven or the first tip-side arm drive motor is stopped.

In the present invention, for example, when the first end-side arm drive motor and the common arm part drive motor are driven while the second end-side arm drive motor is stopped to perform the arm extension and contraction operation, the first end-side arm part When an encoder error occurs in which the drive motor becomes the first motor and the common arm drive motor becomes the second motor, the control unit applies a dynamic brake to the first front arm drive motor to emergency the first front arm drive motor. In addition to stopping, emergency stop while controlling the common arm driving motor based on the output signal of the first encoder installed in the first end-side arm driving motor and the output signal of the second encoder installed in the common arm driving motor, 2 When the first end-side arm drive motor and the common arm drive motor are driven while the distal arm drive motor is stopped, the common arm drive motor becomes the first motor and the first When an encoder error occurs in which the front arm drive motor becomes the second motor, the control unit applies a dynamic brake to the common arm drive motor to emergency stop the common arm drive motor, and the first encoder installed in the common arm drive motor. Based on the output signal of and the output signal of the second encoder installed in the first end arm driving motor, the first arm driving motor is controlled while emergency stop, and the first arm driving motor is stopped. When the second end-side arm drive motor and the common arm drive motor are driven to perform the arm extension and contraction, the second end-side arm drive motor becomes the first motor, and the common arm drive motor becomes the second motor. When an error occurs, the control unit applies a dynamic brake to the second end-side arm drive motor to emergency stop the second end-side arm drive motor, and the output signal of the first encoder installed in the second end-side arm drive motor. And emergency stop while controlling the common arm driving motor based on the output signal of the second encoder installed in the common arm driving motor, and the first arm driving motor When the second end-side arm drive motor and the common arm drive motor are driven to perform the arm extension and contraction operation while is stopped, the common arm drive motor becomes the first motor, and the second end-side arm drive motor is When an encoder error of the second motor occurs, the control unit applies a dynamic brake to the common arm drive motor to emergency stop the common arm drive motor, and the output signal of the first encoder installed in the common arm drive motor and the second An emergency stop is made while controlling the second end-side arm drive motor based on the output signal of the second encoder installed in the front end-side arm drive motor.

In this case, while the second tip-side arm driving motor is stopped, the first tip-side arm driving motor is the first motor during the stretching operation of the arm in which the first tip-side arm driving motor and the common arm driving motor are being driven. And an encoder error in which the common arm drive motor becomes the second motor, or the common arm drive motor becomes the first motor, and the first end-side arm drive motor becomes the second motor. When making an emergency stop of the tip-side arm drive motor and the common arm drive motor, it becomes possible to suppress the deviation of the trajectory of the first hand moving until the arm stops from the design trajectory.

In this case, in the state in which the first end-side arm drive motor is stopped, the second end-side arm drive motor is removed during the extension and contraction of the arm in which the second end-side arm drive motor and the common arm drive motor are driven. An encoder error in which one motor is used and the common arm drive motor becomes the second motor, or the common arm drive motor becomes the first motor, and the second end-side arm drive motor becomes the second motor, When emergency stop of the second end-side arm drive motor and common arm drive motor, it becomes possible to suppress the deviation of the trajectory of the second hand that moves until the arm stops from the design trajectory.

In the present invention, the industrial robot includes a hand rotation motor for rotating the hand with respect to the arm, and a hand encoder for detecting the rotation position of the hand rotation motor, and the hand encoder is If control of the hand rotation motor based on the detection result is impossible as a second encoder error, the control unit emergency stops a plurality of motors and hand rotation motors during driving due to an encoder error occurring during the expansion and contraction of the arm. When performing, emergency stop while controlling the hand rotation motor based on the output signal of the first encoder and the output signal of the hand encoder, and a second encoder error occurs during the extension and contraction of the arm, causing multiple motors and hand rotation during driving. When emergency stop of the motor for hand rotation, a dynamic brake is applied to the motor for hand rotation to emergency stop the motor for hand rotation, and emergency stop of a plurality of motors during driving based on the output signal of the hand encoder and the output signal of the encoder. When an encoder error and a second encoder error occur during the extension and contraction of the arm, and emergency stop of a plurality of motors and hand rotating motors during driving, a dynamic brake is applied to the first motor to emergency stop the first motor, and the hand Emergency stop while controlling the second motor based on the output signal of the hand encoder, the output signal of the first encoder, and the output signal of the second encoder while applying a dynamic brake to the rotating motor to emergency stop the hand rotating motor. It is desirable to make it.

When configured in this way, when an encoder error occurs during the extension and contraction of the arm and an emergency stop of a plurality of motors and hand rotation motors during driving, a dynamic brake is applied and the hand is decelerated according to the deceleration rate of the first motor to stop. It becomes possible to slow down and stop the rotating motor. Therefore, when an encoder error occurs during arm extension and contraction and emergency stop of a plurality of motors and hand rotation motors, it is possible to suppress deviation of the direction of the hand moving from the design direction until the arm stops. Things become possible.

In addition, when configured in this way, when a second encoder error occurs during arm extension and contraction and emergency stop of a plurality of motors and hand rotation motors while driving, a dynamic brake is applied and the deceleration rate of the hand rotation motor decelerates and stops. It becomes possible to decelerate and stop a plurality of motors during driving with a corresponding deceleration rate. Therefore, when a second encoder error occurs during the extension and contraction of the arm and emergency stop of a plurality of motors and hand rotation motors during driving, the direction of the hand moving until the arm stops, from the design direction. It becomes possible to suppress the deviation.

In addition, when configured in this way, when an encoder error and a second encoder error occur during arm extension and contraction, and emergency stop of a plurality of motors and hand rotation motors during driving, a dynamic brake is applied and the first motor decelerates to stop. It is possible to decelerate and stop the second motor with a deceleration rate and a deceleration rate according to the deceleration rate of the hand rotating motor. Therefore, when an encoder error and a second encoder error occur during the extension and contraction of the arm and emergency stop of a plurality of motors and hand rotation motors during driving, the direction of the hand moving while the arm stops. It becomes possible to suppress the deviation from the direction.

As described above, in the present invention, in the horizontal articulated industrial robot having a hand and an arm to which the hand is rotatably connected, the encoder in several motors among a plurality of motors driven during the extension and contraction of the arm. When the control based on the detection result of is not possible, and the encoder error in which the control based on the detection result of the encoder is enabled for the remaining motors occurs during the expansion and contraction of the arm and emergency stop of multiple motors, the arm It becomes possible to suppress the deviation of the trajectory of the hand moving from the design trajectory during this stop.

1 is a plan view of an industrial robot according to an embodiment of the present invention.
2 is a side view of the industrial robot shown in FIG. 1.
3 is a block diagram for explaining the configuration of the industrial robot shown in FIG. 1.
4 is a cross-sectional view for explaining the configuration of a portion E in FIG. 2.
5 is a plan view of an industrial robot according to another embodiment of the present invention, and (B) is a side view of the industrial robot shown in (A).
6 is a block diagram for explaining the configuration of the industrial robot shown in FIG. 5.

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

(Overall composition of industrial robot)

1 is a plan view of an industrial robot 1 according to an embodiment of the present invention. 2 is a side view of the industrial robot 1 shown in FIG. 1. 3 is a block diagram for explaining the configuration of the robot 1 shown in FIG. 1.

The industrial robot 1 of this embodiment (hereinafter referred to as ``robot 1'') is a horizontal articulated type for transporting the glass substrate 2 for a liquid crystal display (hereinafter referred to as ``substrate 2''). It's a robot. The robot 1 transports the substrate 2 in a vacuum. The robot 1 includes two hands 4 and 5 on which the substrate 2 is mounted, an arm 6 to which the hands 4 and 5 are rotatably connected to the tip side, and the base end of the arm 6 It includes a main body portion 7 to which the side is rotatably connected, and a control unit 8 for controlling the robot 1. In addition, the robot 1 includes an arm driving mechanism 9 that expands and contracts the arm 6 with respect to the main body 7 in the horizontal direction, and the hands 4 and 5 and the arm 6 with respect to the main body 7. ) Is provided with a lifting mechanism (not shown) for lifting.

In the arm 6, two distal arm portions 10 and 11 and two distal arm portions 10 and 11 are rotatable with each of the two hands 4 and 5 rotatably connected to the distal end. It has a common arm portion 12 connected to each other. That is, the arm 6 is provided with three arm portions 10 to 12 (tip-side arm portion 10, tip-side arm portion 11, and common arm portion 12) connected so as to be able to rotate relative to each other. The arm 6 of this embodiment is constituted by two tip-side arm portions 10 and 11 and a common arm portion 12.

The hand 4 is rotatably connected to the distal end side of the distal arm 10. The hand 5 is rotatably connected to the distal end side of the distal arm 11. The common arm portion 12 is connected to the body portion 7 so as to be rotatable. The hand 4 of this form is a first hand, and the hand 5 is a second hand. Further, the tip-side arm 10 is a first tip-side arm, and the tip-side arm 11 is a second tip-side arm.

The hand 4 is disposed above the hand 5. The tip-side arm portion 10 is disposed above the hand 4. The distal arm 11 is disposed below the hand 5. The common arm 12 is disposed below the distal arm 11. That is, the tip-side arm portions 10 and 11 are disposed above the common arm portion 12. Moreover, the common arm part 12 is arrange|positioned above the main body part 7.

The main body portion 7 covers an opening at the upper end of the case body 16 and a bottomed cylindrical case body 16 in which an elevator mechanism for raising and lowering the arm 6 and a motor 36 to be described later are accommodated. It has a cover 17. The cover 17 is formed with a flange portion 17a extending outward in the radial direction of the case body 16. As described above, the robot 1 transports the substrate 2 in a vacuum. As shown in FIG. 2, a portion of the robot 1 above the lower surface of the flange portion 17a is disposed in the vacuum chamber 18. That is, a portion of the robot 1 above the lower surface of the flange portion 17a is disposed in the vacuum region VR (in vacuum). On the other hand, a portion of the robot 1 below the lower surface of the flange portion 17a is disposed in the waiting area AR (in the atmosphere).

The hands 4 and 5 are provided with a plurality of fork portions 19 on which the substrate 2 is mounted. The tip-side arm portions 10 and 11 are formed in a block shape having a thin and long elliptical shape when viewed in the vertical direction and thin in the vertical direction. The length of the tip-side arm portion 10 and the length of the tip-side arm portion 11 are made equal. The tip-side arm portions 10 and 11 are formed in a hollow shape. The inside of the tip-side arm portions 10 and 11 formed in a hollow shape is made of vacuum.

The common arm 12 is formed in a substantially V shape. Further, the common arm 12 is formed in a hollow shape. The interior of the common arm 12 is at atmospheric pressure. The central portion of the common arm 12 formed in a substantially V-shape is connected to the main body 7 so as to be rotatable. Further, the proximal end of the distal arm 10 is rotatably connected to one distal end of the common arm 12 formed in a substantially V-shape, and the distal arm 11 is rotatably connected to the other distal end of the common arm 12. The proximal end of) is connected so that it can be rotated. The connecting portion between the tip-side arm portion 10 and the common arm portion 12 is a joint portion 20. The connecting portion between the tip-side arm portion 11 and the common arm portion 12 is a joint portion 21.

The common arm portion 12 includes a base end portion 22 connected to the body portion 7, two tip portions 23 and 24 connected to each of the base end sides of the tip-side arm portions 10 and 11, and two tip portions. It is constituted by two elongated cylindrical connecting portions 25 and 26 connecting each of the 23 and 24 and the base end 22. The proximal end side of the distal arm 10 is connected to the distal end 23, and the proximal end side of the distal arm 11 is connected to the distal end 24. The connection part 25 connects the base end 22 and the distal end 23, and the connection 26 connects the base end 22 and the distal end 24.

(Configuration of arm drive mechanism and control unit)

4 is a cross-sectional view for explaining the configuration of a portion E in FIG. 2.

The arm driving mechanism 9 includes a distal arm driving mechanism 30 that rotates the hand 4 with respect to the distal arm 10 while rotating the distal arm 10 with respect to the common arm 12. , The distal arm drive mechanism 31 for rotating the hand 5 with respect to the distal arm 11 while rotating the distal arm 11 with respect to the common arm 12, and the main body 7 In contrast, it is constituted by a common arm drive mechanism 32 that rotates the common arm 12.

The tip-side arm drive mechanism 30 includes a motor 34 and an encoder 37 for detecting the rotational position of the motor 34. The encoder 37 is installed in the motor 34. The tip-side arm drive mechanism 31 includes a motor 35 and an encoder 38 for detecting the rotational position of the motor 35. The encoder 38 is attached to the motor 35. The common arm drive mechanism 32 includes a motor 36 and an encoder 39 for detecting the rotational position of the motor 36. The encoder 39 is attached to the motor 36.

That is, the arm drive mechanism 9 includes a plurality of motors 34 to 36 for extending and contracting the arm 6, and a plurality of encoders 37 to 39 for detecting rotational positions of the plurality of motors 34 to 36. ). Specifically, the arm drive mechanism 9 is provided with three motors 34 to 36 and three encoders 37 to 39. Further, each of the three encoders 37 to 39 is provided to each of the three motors 34 to 36. The motor 36 of this embodiment is a common arm drive motor for rotating the common arm 12 with respect to the main body 7, and the motor 34 is the distal arm 10 with respect to the common arm 12. A first tip-side arm drive motor for rotating the motor, and the motor 35 is a second tip-side arm drive motor for rotating the tip-side arm 11 with respect to the common arm 12.

Motors 34 to 36 and encoders 37 to 39 are electrically connected to the control unit 8. The encoders 37 to 39 are rotary encoders. The encoders 37 to 39 are provided with, for example, a slit plate fixed to the output shaft of the motors 34 to 36 and a transmission type optical sensor. The optical sensor includes a light-emitting element and a light-receiving element that are disposed opposite to each other with a slit plate sandwiched therebetween.

In addition to the motor 34 and the encoder 37, the tip-side arm drive mechanism 30 includes a reduction gear 44 connected to the motor 34. The reduction gear 44 is a hollow wave gear device, and is disposed in the joint portion 20. The reduction gear 44 is provided with a rotation shaft 45 serving as an output shaft of the reduction gear 44, a bearing supporting the rotation shaft 45 so as to be rotatable, and a magnetic fluid seal disposed on the outer circumference of the rotation shaft 45. Are doing. The case body of the speed reducer 44 is fixed to the distal end 23.

Further, the distal arm drive mechanism 30 includes a pulley 48 fixed to the input shaft 46 of the speed reducer 44, a pulley 49 disposed inside the proximal end side of the distal arm 10, A pulley 50 is provided inside the distal end of the distal arm 10. In this embodiment, the ratio of the pitch circle diameter of the pulley 49 and the pitch circle diameter of the pulley 50 is set to 1:2 so that the hand 4 moves linearly in a state facing a certain direction.

The rotation shaft 45 is formed in a hollow shape. The rotation shaft 45 is fixed to the lower surface of the proximal end side of the distal arm 10 via a rotation shaft 52 formed in a hollow shape. The motor 34 is fixed to the distal end 23. Further, the motor 34 is disposed inside the tip portion 23. A pulley 53 is fixed to the output shaft of the motor 34. A belt 54 is strung on the pulley 48 and the pulley 53. The pulleys 48 and 53 and the belt 54 are arranged inside the tip 23.

A support shaft 55 for supporting the pulley 49 so as to be rotatable is fixed inside the proximal end side of the distal arm 10. The axial center of the support shaft 55 coincides with the axial center of the rotation shaft 45. The pulley 49 is rotatably supported by the support shaft 55 via a bearing. Further, the pulley 49 is fixed to the distal end 23 via a fixing member 56. The fixing member 56 is disposed outside the joint portion 20. A support shaft portion 10b for supporting the pulley 50 so as to be rotatable is formed inside the front end side of the front arm portion 10. The pulley 50 is rotatably supported by the support shaft portion 10b via a bearing. Further, at the lower end of the pulley 50, the base end side of the hand 4 is fixed. A belt 57 is hung between the pulley 49 and the pulley 50.

The tip-side arm drive mechanism 31 is configured almost the same as the tip-side arm drive mechanism 30. Therefore, in the following, the configuration of the tip-side arm drive mechanism 31 will be described centering on the difference from the tip-side arm drive mechanism 30. In addition to the motor 35 and the encoder 38, the tip-side arm drive mechanism 31 includes a reduction gear 44 connected to the motor 35, similarly to the tip-side arm drive mechanism 30. The reducer 44 of the tip-side arm drive mechanism 31 is disposed in the joint 21. The case body of the speed reducer 44 of the distal arm drive mechanism 31 is fixed to the distal end 24.

Further, the distal arm drive mechanism 31 includes a pulley 48 fixed to the input shaft 46 of the reducer 44 of the distal arm drive mechanism 31, similar to the distal arm drive mechanism 30, A pulley 49 disposed inside the proximal end side of the distal arm 11 and a pulley 50 disposed inside the distal end side of the distal arm 11 are provided. The rotation shaft 45 of the speed reducer 44 of the tip-side arm drive mechanism 31 is fixed to the lower surface of the tip-side arm 11 on the base end side. The motor 35 is fixed to the distal end 24. Further, the motor 35 is disposed inside the tip portion 24. A pulley 53 is fixed to the output shaft of the motor 35.

A support shaft 55 for supporting the pulley 49 so as to be rotatable is fixed inside the base end side of the distal arm 11. The pulley 49 is fixed to the distal end 24 via a fixing member 56. A support shaft for supporting the pulley 50 so as to be able to rotate is formed inside the tip side of the tip-side arm 11. The pulley 50 is rotatably supported on a support shaft via a bearing. Moreover, the base end side of the hand 5 is fixed to the upper end of the pulley 50.

In addition to the motor 36 and the encoder 39, the common arm drive mechanism 32 includes a reduction gear connected to the motor 36. This speed reducer, motor 36 and encoder 39 are arranged inside the case body 16. The case body of the speed reducer is fixed to the case body 16. The rotation shaft serving as the output shaft of the speed reducer is fixed to the lower surface of the common arm 12 (specifically, the lower surface of the base end 22) through a predetermined rotation shaft formed in a hollow shape. A belt is strung between the pulley fixed to the input shaft of the speed reducer and the pulley fixed to the output shaft of the motor 36.

As described above, the motors 34 to 36 and the encoders 37 to 39 are electrically connected to the control unit 8. The control unit 8 includes a motor control unit 61 that controls the motor 34 based on a detection result of the encoder 37, and a motor control unit 61 that controls the motor 35 based on the detection result of the encoder 38 62) and a motor control unit 63 that controls the motor 36 based on the detection result of the encoder 39. The output signal of the encoder 37 can be input to the motor control unit 61. The output signal of the encoder 38 can be input to the motor control unit 62. The output signal of the encoder 39 can be input to the motor control unit 63.

Further, to the motor control unit 61, the output signal of the encoder 39 can be input via the motor control unit 63 or directly. The output signal of the encoder 39 can be input to the motor control unit 62 via the motor control unit 63 or directly. In the motor control unit 63, the output signal of the encoder 37 can be input through the motor control unit 61 or directly, and the output signal of the encoder 38 is transmitted through the motor control unit 62. Or, it can be input directly.

The motor control unit 61 is provided with a dynamic brake control circuit for operating the dynamic brake on the motor 34. The motor control unit 62 includes a dynamic brake control circuit for operating the dynamic brake on the motor 35. The motor control unit 63 is provided with a dynamic brake control circuit for operating the dynamic brake on the motor 36.

The control unit 8 drives any one of the two motors 34 and 35 and the motor 36 during the expansion and contraction operation of the arm 6. That is, when the arm 6 is stretched and contracted, the motor 34 and the motor 36 are driven while the motor 35 is stopped, or the motor 35 is driven while the motor 34 is stopped. And the motor 36 is driven. Further, the arm drive mechanism 9 expands and contracts the arm 6 in the horizontal direction so that the hand 4 or the hand 5 moves linearly in a state facing a predetermined direction.

That is, the rotation direction of the common arm portion 12 with respect to the body portion 7 and the rotation direction of the distal arm portions 10 and 11 with respect to the common arm portion 12 are reversed, and the rotation direction of the body portion 7 The motor 34 or the motor 35 and the motor 36 so that the ratio of the rotation amount of the common arm portion 12 and the rotation amount of the tip-side arm portions 10 and 11 to the common arm portion 12 is 1:2. ) Is driven to expand and contract the arm 6 in the horizontal direction.

(Control method of industrial robot)

Control based on the detection results of the encoders 37 to 39 is impossible in some of the motors 34 to 36 among the plurality of motors 34 to 36 that are being driven during the extension and contraction of the arm 6, and the rest A case in which control based on the detection results of the encoders 37 to 39 in the motors 34 to 36 is enabled is referred to as an encoder error, and is based on the detection results of the encoders 37 to 39 when an encoder error occurs. The driving motors 34 to 36 in which the control is disabled is referred to as the first motor, and the motor during driving in which control based on the detection result of the encoders 37 to 39 when an encoder error occurs ( 34 to 36) are referred to as the second motor, the encoders 37 to 39 installed in the first motor are referred to as the first encoder, and the encoders 37 to 39 installed in the second motor are referred to as the second encoder. , The control unit 8 applies a dynamic brake to the first motor to emergency stop the first motor when an encoder error occurs during the expansion and contraction operation of the arm 6 and emergency stops the plurality of motors 34 to 36 during driving. Together with the sikim, an emergency stop is made while controlling the second motor based on the output signal of the first encoder and the output signal of the second encoder.

That is, for example, when the motor 34 and the motor 36 are driven in a state in which the motor 35 is stopped and the arm 6 is expanding and contracted, the motor 34 becomes the first motor ( That is, control of the motor 34 based on the detection result of the encoder 37 becomes impossible), and the motor 36 becomes the second motor (that is, the motor based on the detection result of the encoder 39 ( 36) control is enabled), when an encoder error occurs, the control unit 8 applies a dynamic brake to the motor 34 to emergency stop the motor 34, and the controller 8 is installed in the motor 34. An emergency stop is made while controlling the motor 36 based on the output signal of the 1 encoder (ie, the encoder 37) and the output signal of the second encoder (ie, the encoder 39) installed in the motor 36.

Specifically, when such an encoder error occurs, the motor control unit 61 applies a dynamic brake to the motor 34 to emergency stop the motor 34, and the motor control unit 63 Based on the output signal and the output signal of the encoder 39, the motor 36 is decelerated by a deceleration rate corresponding to the deceleration rate of the motor 34 to cause an emergency stop. In addition, the motor control unit 63, based on the output signal of the encoder 37 and the output signal of the encoder 39, until the arm 6 stops, the common arm for the main body 7 ( The motor 36 is controlled so that the rotation amount of 12) becomes 1/2 times the rotation amount of the distal arm 10 with respect to the common arm 12.

Further, for example, when the motor 34 and the motor 36 are driven in a state in which the motor 35 is stopped and the arm 6 is expanded and contracted, the motor 36 becomes the first motor ( That is, control of the motor 36 based on the detection result of the encoder 39 becomes impossible), and the motor 34 becomes the second motor (that is, a motor based on the detection result of the encoder 37 ( 34) control is enabled), when an encoder error occurs, the control unit 8 applies a dynamic brake to the motor 36 to stop the motor 36 in an emergency, and the controller 8 installed in the motor 36 An emergency stop is made while controlling the motor 34 based on the output signal of the 1 encoder (ie, the encoder 39) and the output signal of the second encoder (ie, the encoder 37) installed in the motor 34.

Specifically, when such an encoder error occurs, the motor control unit 63 applies a dynamic brake to the motor 36 to stop the motor 36 in an emergency, and the motor control unit 61 causes the encoder 37 to Based on the output signal and the output signal of the encoder 39, the motor 34 is decelerated by a deceleration rate corresponding to the deceleration rate of the motor 36 to cause an emergency stop. Further, the motor control unit 61 is based on the output signal of the encoder 37 and the output signal of the encoder 39, while the arm 6 is stopped, the distal arm of the common arm 12 The motor 34 is controlled so that the rotation amount of (10) is twice the rotation amount of the common arm 12 with respect to the main body 7.

Further, for example, when the motor 35 and the motor 36 are driven in a state in which the motor 34 is stopped and the arm 6 is expanded and contracted, the motor 35 becomes the first motor ( That is, control of the motor 35 based on the detection result of the encoder 38 becomes impossible), and the motor 36 becomes a second motor (that is, a motor based on the detection result of the encoder 39 ( 36) control is enabled), when an encoder error occurs, the control unit 8 applies a dynamic brake to the motor 35 to emergency stop the motor 35, and the controller 8 is installed in the motor 35. An emergency stop is made while controlling the motor 36 based on the output signal of the 1 encoder (ie, the encoder 38) and the output signal of the second encoder (ie, the encoder 39) installed in the motor 36.

Specifically, when such an encoder error occurs, the motor control unit 62 applies a dynamic brake to the motor 35 to emergency stop the motor 35, and the motor control unit 63 Based on the output signal and the output signal of the encoder 39, the motor 36 is decelerated by a deceleration rate corresponding to the deceleration rate of the motor 35 to cause an emergency stop. Further, the motor control unit 63 is based on the output signal of the encoder 38 and the output signal of the encoder 39, while the arm 6 is stopped, the common arm for the main body 7 ( The motor 36 is controlled so that the rotation amount of 12) becomes 1/2 times the rotation amount of the distal arm 11 with respect to the common arm 12.

In addition, for example, when the motor 35 and the motor 36 are driven in a state in which the motor 34 is stopped and the arm 6 is expanded and contracted, the motor 36 becomes the first motor ( That is, control of the motor 36 based on the detection result of the encoder 39 becomes impossible), and the motor 35 becomes a second motor (that is, a motor based on the detection result of the encoder 38 ( 35) control is enabled), when an encoder error occurs, the control unit 8 applies a dynamic brake to the motor 36 to emergency stop the motor 36, and the controller 8 is installed in the motor 36. An emergency stop is made while controlling the motor 35 based on the output signal of the 1 encoder (ie, the encoder 39) and the output signal of the second encoder (ie, the encoder 38) installed in the motor 35.

Specifically, when such an encoder error occurs, the motor control unit 63 applies a dynamic brake to the motor 36 to emergency stop the motor 36, and the motor control unit 62 causes the encoder 38 to Based on the output signal and the output signal of the encoder 39, the motor 35 is decelerated by a deceleration rate corresponding to the deceleration rate of the motor 36 to cause an emergency stop. Further, the motor control unit 62 is based on the output signal of the encoder 38 and the output signal of the encoder 39, while the arm 6 is stopped, the distal arm of the common arm 12 The motor 35 is controlled so that the rotation amount of (11) is twice the rotation amount of the common arm 12 with respect to the main body 7.

(Main effect of this form)

As described above, in this embodiment, when the motors 34 and 36 are driven in a state in which the motor 35 is stopped and the arm 6 is expanding and contracted, the motor 34 becomes the first motor. In addition, when an encoder error occurs in which the motor 36 becomes the second motor, the motor control unit 61 applies a dynamic brake to the motor 34 to stop the motor 34 in an emergency, and the motor control unit 63 Is, based on the output signals of the encoders 37 and 39, emergency stop while controlling the motor 36. In addition, in this embodiment, the motor control part 63 is based on the output signal of the encoders 37 and 39 while the arm 6 stops, the common arm part 12 with respect to the main body part 7 The motor 36 is controlled so that the amount of rotation of is 1/2 times the amount of rotation of the distal arm part 10 with respect to the common arm part 12. Therefore, in this embodiment, when such an encoder error occurs during the expansion and contraction of the arm 6 and the motors 34 and 36 are emergency stop, the hand 4 that moves while the arm 6 stops. It becomes possible to suppress the deviation of the trajectory of from from the design trajectory (linear trajectory).

Further, in this embodiment, when the motors 34 and 36 are driven in a state in which the motor 35 is stopped and the arm 6 is expanding and contracted, the motor 36 becomes the first motor, and the motor When an encoder error of 34 being the second motor occurs, the motor control unit 63 applies a dynamic brake to the motor 36 to emergency stop the motor 36, and the motor control unit 61 returns the encoder Based on the output signals of (37, 39), the amount of rotation of the distal arm portion 10 relative to the common arm portion 12 with respect to the body portion 7 while the arm 6 stops. While controlling the motor 34 so as to be twice the rotation amount of 12), an emergency stop is made. Therefore, in this embodiment, when such an encoder error occurs during the expansion and contraction of the arm 6 and the motors 34 and 36 are emergency stop, the hand 4 that moves while the arm 6 stops. It becomes possible to suppress the deviation of the trajectory of from from the design trajectory.

Further, in this embodiment, when the motors 35 and 36 are driven in a state in which the motor 34 is stopped and the arm 6 is expanding and contracted, the motor 35 becomes the first motor, and the motor When an encoder error of 36 being the second motor occurs, the motor control unit 62 applies a dynamic brake to the motor 35 to emergency stop the motor 35, and the motor control unit 63 returns the encoder Based on the output signals of (38, 39), while the arm 6 stops, the amount of rotation of the common arm 12 with respect to the main body 7 is the distal arm ( While controlling the motor 36 so as to be 1/2 of the rotation amount of 11), an emergency stop is made. Therefore, in the present embodiment, when such an encoder error occurs during the extension and contraction of the arm 6 and the motors 35 and 36 are emergency stop, the hand 5 that moves while the arm 6 stops. It becomes possible to suppress the deviation of the trajectory of from from the design trajectory.

Further, in this embodiment, when the motors 35 and 36 are driven in a state in which the motor 34 is stopped and the arm 6 is expanding and contracted, the motor 36 becomes the first motor, and the motor When an encoder error of (35) being the second motor occurs, the motor control unit 63 applies a dynamic brake to the motor 36 to emergency stop the motor 36, and the motor control unit 62 returns the encoder Based on the output signals of (38, 39), the amount of rotation of the tip-side arm 11 relative to the common arm 12 relative to the common arm portion 7 while the arm 6 stops. While controlling the motor 35 so as to be twice the rotation amount of 12), an emergency stop is made. Therefore, in the present embodiment, when such an encoder error occurs during the extension and contraction of the arm 6 and the motors 35 and 36 are emergency stop, the hand 5 that moves while the arm 6 stops. It becomes possible to suppress the deviation of the trajectory of from from the design trajectory.

Further, for example, at a predetermined timing in which the motors 34 and 36 are driven while the motor 35 is stopped and the arm 6 is expanding and contracted, a dynamic brake is applied to the motor 34 to apply a dynamic brake to the motor ( 34), while controlling the motor 36 based on the output signals of the encoders 37 and 39, the inventor of the present invention conducted an experiment of emergency stopping. As a result, during the period until the arm 6 stops The trajectory of the moving hand 4 hardly deviated from the design trajectory (linear trajectory), and the stopped hand 4 hardly deviated from the design trajectory when viewed from above.

On the other hand, as a comparative experiment 1, a dynamic brake is applied to the motor 34 at a predetermined timing in which the motors 34 and 36 are driven in a state in which the motor 35 is stopped and the extension and contraction of the arm 6 is performed. As a result of the inventor of the present invention conducting an experiment of emergency stopping the motor 34 while controlling the motor 36 based on the output signal of only the encoder 39, while the arm 6 is stopped, The trajectory of the moving hand 4 is largely deviated from the design trajectory, and the stationary hand 4 is largely deviated from the design trajectory when viewed from above. Specifically, in the experimental results of Comparative Experiment 1, when the state after the hand 4 has stopped is viewed from above, the rotation center of the common arm 12 with respect to the body 7 and the distal arm 10 The angle between the imaginary line connecting the rotation center of the Daehan hand 4 and the design trajectory (linear trajectory) was about 12°.

In addition, as a comparative experiment 2, a dynamic brake is applied to the motor 34 at a predetermined timing in which the motors 34 and 36 are driven while the motor 35 is stopped and the arm 6 is expanding and contracted. As a result of the inventor of the present invention performing an experiment of emergency stopping the motor 36 by applying a dynamic brake to the motor 36 while making an emergency stop of the motor 34, a hand that moves while the arm 6 stops The deviation of the trajectory of (4) from the design trajectory is smaller than the experimental result of Comparative Experiment 1, but the trajectory of the hand 4 moving until the arm 6 stops, according to the design. A deviation from the trajectory occurred, and the stopped hand 4 was deviated from the design trajectory when viewed from above. Specifically, in the experimental results of Comparative Experiment 2, when the state after the hand 4 has stopped is viewed from above, the rotation center of the common arm 12 with respect to the main body 7 and the distal arm 10 The angle between the imaginary line connecting the rotation center of the Daehan hand 4 and the design trajectory (linear trajectory) was about 4.5°.

(Modified example 1 of industrial robot)

Fig. 5A is a plan view of a robot 1 according to another embodiment of the present invention, and Fig. 5B is a side view of the robot 1 shown in Fig. 5A. 6 is a block diagram for explaining the configuration of the robot 1 shown in FIG. 5.

As shown in Fig. 5, the robot 1 includes one hand 4 on which the substrate 2 is mounted, an arm 6 to which the hand 4 is rotatably connected to the distal end, and an arm ( The base end side of 6) may be provided with the main body part 7 which is connected so that rotation is possible. In this case, the arm 6 includes an arm portion 71 in which the hand 4 is rotatably connected to the tip side, and an arm portion 72 in which the base end side of the arm portion 71 is rotatably connected to the tip side. Consists of. The base end side of the arm part 72 is connected to the main body part 7 so that rotation is possible. In addition, in Figs. 5 and 6, the same reference numerals are assigned to configurations similar to those of the above-described form.

In addition, in this case, the robot 1 is, for example, an arm driving mechanism 9 that expands and contracts the arm 6 with respect to the main body 7 in the horizontal direction, and the hand 4 with respect to the arm 6. It has a hand drive mechanism 73 which rotates. The arm drive mechanism 9 includes a first arm drive mechanism 75 for rotating the arm 71 with respect to the arm 72, and a second arm drive mechanism for rotating the arm 72 with respect to the body 7 It has (76).

The first arm drive mechanism 75 includes a motor 78 and an encoder 81 for detecting the rotational position of the motor 78. The encoder 81 is installed in the motor 78. The second arm drive mechanism 76 includes a motor 79 and an encoder 82 for detecting the rotational position of the motor 79. The encoder 82 is installed in the motor 79. The hand drive mechanism 73 includes a motor 80 and an encoder 83 for detecting the rotational position of the motor 80. The encoder 83 is installed in the motor 80. In this modification, the motor 80 is a hand rotation motor for rotating the hand 4 with respect to the arm 6. Further, the encoder 83 is a hand encoder.

In addition to the motor 78 and the encoder 81, the 1st arm drive mechanism 75 is provided with the reducer connected to the motor 78, for example. The case body of this speed reducer is fixed to the arm 72. Further, the rotation shaft serving as the output shaft of this speed reducer is fixed to the lower surface of the arm 71 on the base end side. Further, a belt is strung between the pulley fixed to the input shaft of this reducer and the pulley fixed to the output shaft of the motor 78.

In addition to the motor 79 and the encoder 82, the 2nd arm drive mechanism 76 is provided with the reduction gear connected to the motor 79, for example. The case body of this reducer is fixed to the case body 16. Further, the rotation shaft serving as the output shaft of this speed reducer is fixed to the lower surface of the arm 72 on the base end side. Further, a belt is strung between the pulley fixed to the input shaft of this reducer and the pulley fixed to the output shaft of the motor 79.

In addition to the motor 80 and the encoder 83, the hand drive mechanism 73 is provided with, for example, a reduction gear connected to the motor 80. The case body of this speed reducer is fixed to the arm 71. Further, the rotation shaft serving as the output shaft of this speed reducer is fixed to the lower surface of the hand 4. Further, a belt is strung between the pulley fixed to the input shaft of this reducer and the pulley fixed to the output shaft of the motor 80.

Motors 78 to 80 and encoders 81 to 83 are electrically connected to the control unit 8. The encoders 81 to 83 are rotary encoders configured similarly to the encoders 37 to 39. The control unit 8 includes a motor control unit 91 that controls the motor 78 based on the detection result of the encoder 81 and a motor control unit 91 that controls the motor 79 based on the detection result of the encoder 82 92) and a motor control unit 93 that controls the motor 80 based on the detection result of the encoder 83. The output signal from the encoder 81 can be input to the motor control unit 91. The output signal of the encoder 82 can be input to the motor control unit 92. The output signal from the encoder 83 can be input to the motor control unit 93.

Further, to the motor control unit 91, the output signal of the encoder 82 can be input through the motor control unit 92 or directly, and the output signal of the encoder 83 is transmitted to the motor control unit 93 Through or directly, input is possible. In the motor control unit 92, the output signal of the encoder 81 can be input through the motor control unit 91 or directly, and the output signal of the encoder 83 is transmitted through the motor control unit 93. Or, it can be input directly. In the motor control unit 93, the output signal of the encoder 81 can be input through the motor control unit 91 or directly, and the output signal of the encoder 82 is transmitted through the motor control unit 92. Or, it can be input directly.

The motor control unit 91 is provided with a dynamic brake control circuit for operating the dynamic brake on the motor 78. The motor control unit 92 includes a dynamic brake control circuit for operating the dynamic brake on the motor 79. The motor control unit 93 is provided with a dynamic brake control circuit for operating the dynamic brake on the motor 80.

The control unit 8 drives the motors 78 to 80 during the expansion and contraction operation of the arm 6. Further, the arm drive mechanism 9 and the hand drive mechanism 73 expand and contract the arm 6 in the horizontal direction so that the hand 4 moves linearly with the hand 4 facing a certain direction. That is, the direction of rotation of the arm portion 72 with respect to the body portion 7 and the direction of rotation of the arm portion 71 with respect to the arm portion 72 are reversed, and the direction of rotation of the arm portion 71 with respect to the arm portion 72 And, while the rotation direction of the hand 4 with respect to the arm 71 is reversed, the amount of rotation of the arm 72 with respect to the main body 7 and the amount of rotation of the arm 71 with respect to the arm 72 And, the motors 78 to 80 are driven so that the ratio of the rotation amount of the hand 4 to the arm 71 is 1:2:1 to expand and contract the arm 6 in the horizontal direction.

During the expansion and contraction operation of the arm 6, control based on the detection result of the encoders 81 and 82 in either of the motor 78 and the motor 79 becomes impossible, and the motor 78 and the motor 79 The case in which the control based on the detection result of the encoders 81 and 82 is enabled in either of the other is referred to as an encoder error, and control based on the detection result of the encoders 81 and 82 when an encoder error occurs. The motors 78 and 79 that are disabled are referred to as the first motor, and the motors 78 and 79 capable of controlling based on the detection result of the encoders 81 and 82 when an encoder error occurs are referred to as the second motor. The motor is referred to as a motor, and the encoders 81 and 82 installed in the first motor are referred to as the first encoder, and the encoders 81 and 82 installed in the second motor are referred to as the second encoder, and the arm 6 is extended or contracted. Assuming that the case in which control of the motor 80 based on the detection result of the encoder 83 during operation becomes impossible is referred to as a second encoder error, the control unit 8 is determined by the encoder error or the second encoder error during the stretching operation of the arm 6. When an encoder error occurs to emergency stop the motors 78 to 80, the motors 78 to 80 are emergency stop as follows.

For example, when an encoder error occurs in which the motor 78 becomes the first motor and the motor 79 becomes the second motor, the control unit 8 applies a dynamic brake to the motor 78 and applies a dynamic brake to the motor 78. ) To emergency stop, and control the motor 79 based on the output signal of the encoder 81, which is the first encoder, and the output signal of the encoder 82, which is the second encoder. An emergency stop is made while controlling the motor 80 based on the output signal of the encoder 81 and the output signal of the encoder 83.

Specifically, when such an encoder error occurs, the motor control unit 91 applies a dynamic brake to the motor 78 to stop the motor 78 in an emergency, and the motor control unit 92 responds to the encoders 81 and 82 Based on the output signal of, the motor 79 is decelerated to an emergency stop by deceleration according to the deceleration rate of the motor 78, and the motor control unit 93, based on the output signals of the encoders 81 and 83 , The motor 80 is decelerated by a deceleration rate according to the deceleration rate of the motor 78 to make an emergency stop. In addition, the motor control unit 92, based on the output signals of the encoders 81 and 82, the amount of rotation of the arm 72 with respect to the body 7 until the arm 6 stops. The motor 79 is controlled to be 1/2 times the rotation amount of the arm 71 relative to 72, and the motor controller 93, based on the output signals of the encoders 81 and 83, the arm 6 The motor 80 is controlled so that the amount of rotation of the hand 4 with respect to the arm 71 is 1/2 times the amount of rotation of the arm 71 with respect to the arm 72 until it stops.

In addition, for example, when an encoder error occurs in which the motor 79 becomes the first motor and the motor 78 becomes the second motor, the motor control unit 92 applies a dynamic brake to the motor 79 Emergency stop 79, and also, based on the output signal of the encoders 81 and 82, the motor control unit 91 decelerates the motor 78 by deceleration according to the deceleration rate of the motor 79 to make an emergency stop. In addition, the motor control unit 93 decelerates the motor 80 to an emergency stop by a deceleration rate corresponding to the deceleration rate of the motor 79 based on the output signals of the encoders 82 and 83. In addition, the motor control unit 91, based on the output signals of the encoders 81 and 82, the amount of rotation of the arm 71 relative to the arm 72 relative to the arm 72 while the arm 6 stops. The motor 78 is controlled so that the rotation amount of the arm 72 relative to 7) is doubled, and the motor control unit 93, based on the output signals of the encoders 82 and 83, the arm 6 is stopped. Until then, the motor 80 is controlled so that the amount of rotation of the hand 4 with respect to the arm 71 is equal to the amount of rotation of the arm 72 with respect to the main body 7.

In addition, for example, when a second encoder error occurs, the control unit 8 applies a dynamic brake to the motor 80 to emergency stop the motor 80, and the output signal of the encoder 83 and the encoder 81 ) To control the motor 78 based on the output signal of) and to make an emergency stop while controlling the motor 79 based on the output signal of the encoder 82 and the output signal of the encoder 83.

Specifically, when such an encoder error occurs, the motor control unit 93 applies a dynamic brake to the motor 80 to emergency stop the motor 80, and the motor control unit 91 returns the encoders 81 and 83 ), the motor 78 is decelerated by a deceleration according to the deceleration rate of the motor 80 to make an emergency stop, and the motor control unit 92 is based on the output signals of the encoders 82 and 83 , The motor 79 is decelerated by a deceleration rate according to the deceleration rate of the motor 80 to make an emergency stop. Further, based on the output signals of the encoders 81 and 83, the motor control unit 91 has the amount of rotation of the arm 71 with respect to the arm 72 until the arm 6 stops. ), the motor 78 is controlled to be twice the amount of rotation of the hand 4 with respect to ), and the motor control unit 92, based on the output signals of the encoders 82, 83, the arm portion for the main body 7 The motor 79 is controlled so that the amount of rotation of the hand 72 is equal to the amount of rotation of the hand 4 with respect to the arm 71.

In this modified example, when an encoder error or a second encoder error occurs during the expansion and contraction of the arm 6 to emergency stop the motors 78 to 80, the hand that moves while the arm 6 stops ( It becomes possible to suppress the deviation of the trajectory of 4) from the design trajectory (linear trajectory). In addition, in this modified example, when an encoder error or a second encoder error occurs during the expansion and contraction of the arm 6 to emergency stop the motors 78 to 80, it moves while the arm 6 stops. It becomes possible to suppress the deviation of the direction of the hand 4 from the design direction.

(Variant 2 of industrial robot)

In the modified example shown in Figs. 5 and 6, during the expansion and contraction operation of the arm 6, for example, the motor 78 becomes the first motor, and the motor 79 becomes the second motor. , There is a possibility that a second encoder error may occur. When such an encoder error and a second encoder error occur and emergency stop of the motors 78 to 80, the control unit 8 applies a dynamic brake to the motor 78 to emergency stop the motor 78, and the motor 80 ) By applying a dynamic brake to emergency stop the motor 80, while controlling the motor 79 based on the output signal of the encoder 83, the output signal of the encoder 81, and the output signal of the encoder 82. Emergency stop.

In this case, when an encoder error and a second encoder error occur during the expansion and contraction of the arm 6 to emergency stop the motors 78 to 80, a dynamic brake is applied to the first motor (for example, It is possible to decelerate and stop the second motor (for example, the motor 79) with a deceleration rate of the motor 78 and a deceleration rate corresponding to the deceleration rate of the motor 80. Therefore, when an encoder error and a second encoder error occur during the extension and contraction of the arm 6 to emergency stop the motors 78 to 80, the hand 4 moving while the arm 6 stops. It is possible to suppress the deviation of the trajectory from the design trajectory (linear trajectory), and the deviation of the direction of the hand 4 moving until the arm 6 stops, from the design direction. It becomes possible to suppress it.

In addition, in the modified example shown in FIGS. 5 and 6, the robot 1 does not have to be equipped with the hand drive mechanism 73. In this case, the first arm drive mechanism 75 rotates the arm 71 with respect to the arm 72 and rotates the hand 4 with respect to the arm 71. Further, in this modified example, the robot 1 may be provided with two hands 4 and two arms 6, each of which is rotatably connected to the tip side. . That is, the robot 1 may be a double arm type robot.

In addition, in the modified example shown in FIG. 5 and FIG. 6, the arm 6 may be comprised by three or more arm parts which are mutually connected so that relative rotation is possible. In this case, for example, the arm 6 includes a first arm portion rotatably connected to the body portion 7 at the base end side and a second arm portion rotatably connected to the front end side of the first arm portion And, the base end is rotatably connected to the distal end of the second arm, and the hand 4 is rotatably connected to the distal end. In this case, for example, the arm drive mechanism 9 includes a motor for rotating the first arm portion with respect to the body portion 7, a motor for rotating the second arm portion with respect to the first arm portion, and 2 A motor is provided for rotating the third arm with respect to the arm and for rotating the hand 4 with respect to the third arm. That is, the arm drive mechanism 9 is provided with three motors for expanding and contracting the arm 6.

In this case, control based on the detection result of the encoder in one or two of the three motors being driven during the extension and contraction operation of the arm 6 becomes impossible, and the remaining two or one motor The case in which control based on the detection result of is enabled is called an encoder error, and the motor in which control based on the detection result of the encoder is disabled when an encoder error occurs is called the first motor, and an encoder error occurs. At the time, the motor that enables control based on the detection result of the encoder is referred to as the second motor, the encoder installed in the first motor is referred to as the first encoder, and the encoder installed in the second motor is referred to as the second encoder. In other words, when an encoder error occurs during the expansion and contraction of the arm 6 and emergency stop of the three motors, the control unit 8 applies a dynamic brake to the first motor to emergency stop the first motor, Emergency stop while controlling the second motor based on the output signal of the 1 encoder and the output signal of the second encoder.

(Other embodiment)

Although the above-described form is an example of a preferred form of the present invention, it is not limited thereto, and various modifications are possible without changing the gist of the present invention.

In the above-described form, between the hand 4 and the common arm 12, two or more tip-side arm portions that are connected so as to be able to rotate relative to each other may be disposed. In addition, in the above-described form, two or more distal arm portions may be disposed between the hand 5 and the common arm portion 12 so as to be rotatably connected to each other. In addition, in the above-described form, the common arm 12 may be formed in a straight line. In addition, in the above-described aspect, the robot 1 may transport objects to be transported other than the glass substrate 2 for liquid crystal displays. For example, the robot 1 may convey the glass substrate for organic EL (organic electroluminescence) displays, and may convey the semiconductor wafer.

1: Robot (industrial robot)
4: hand (first hand)
5: hand (second hand)
6: cancer
7: main body
8: control unit
9: arm drive mechanism
10: distal arm (arm part, first distal arm)
11: Distal arm (arm part, second distal arm)
12: common arm (arm)
34: motor (first end-side arm drive motor)
35: motor (second end-side arm drive motor)
36: motor (common arm drive motor)
37 to 39, 81, 82: encoder
71, 72: dark part
78, 79: motor
80: Motor (motor for hand rotation)
83: Encoder (hand encoder)

Claims (5)

In the horizontal articulated industrial robot,
A hand, an arm rotatably connected to the distal end of the hand while having at least two arm parts rotatably connected to the hand, a body part rotatably connected to the base end of the arm, and the body part With respect to the arm drive mechanism for extending and contracting the arm in a horizontal direction, and a control unit for controlling the industrial robot,
The arm drive mechanism includes a plurality of motors for expanding and contracting the arm, and a plurality of encoders for detecting rotational positions of the plurality of motors,
Each of the plurality of encoders is installed on each of the plurality of motors,
Control based on the detection result of the encoder becomes impossible in some of the motors among the plurality of motors that are being driven during the stretching and contracting operation of the arm, and the control based on the detection result of the encoder in the remaining motors When the encoder error is enabled, the motor during driving in which control based on the detection result of the encoder is disabled when the encoder error occurs is referred to as the first motor, and when the encoder error occurs. The motor during driving in which control based on the detection result of the encoder is enabled is referred to as a second motor, and the encoder installed in the first motor is referred to as a first encoder, and is installed in the second motor. Let the encoder be the second encoder,
The control unit applies a dynamic brake to the first motor to emergency stop the first motor when the encoder error occurs during the extension and contraction operation of the arm to emergency stop the plurality of motors during driving, and the first motor An industrial robot, characterized in that for emergency stop while controlling the second motor based on an output signal of one encoder and an output signal of the second encoder. The method of claim 1,
As the hand, comprising a first hand and a second hand,
The arm is the arm, wherein the first hand is rotatably connected to the distal end, the second distal arm is rotatably connected to the distal end, and the second hand 1 A proximal end side of the distal arm portion and a proximal end side of the second distal arm portion are rotatably connected, and a common arm part rotatably connected to the main body portion is provided,
The arm driving mechanism is the motor, comprising: a common arm driving motor for rotating the common arm with respect to the main body; and a first tip-side arm driving motor for rotating the first tip arm with respect to the common arm. And, a second tip-side arm drive motor for rotating the second tip-side arm with respect to the common arm,
When the arm is extended and contracted, the first front arm driving motor and the common arm driving motor are driven while the second tip arm driving motor is stopped, or the first tip arm driving motor is The industrial robot, characterized in that the second end-side arm driving motor and the common arm driving motor are driven in a stopped state. The method of claim 2,
When the first tip-side arm driving motor and the common arm driving motor are driven while the second tip-side arm driving motor is stopped to perform an extension and contraction operation of the arm, the first tip-side arm driving motor is When the encoder error occurs in which the first motor is used and the common arm driving motor is the second motor, the controller applies a dynamic brake to the first tip arm driving motor to apply a dynamic brake to the first tip arm driving motor. The common arm is driven based on the output signal of the first encoder installed in the first end-side arm driving motor and the output signal of the second encoder installed in the common arm driving motor while emergency stopping the driving motor. Emergency stop while controlling the motor,
When the first tip-side arm driving motor and the common arm driving motor are driven while the second tip-side arm driving motor is stopped, the common arm driving motor is the first When the encoder error occurs in which the motor becomes a motor and the first end-side arm drive motor becomes the second motor, the control unit applies a dynamic brake to the common arm drive motor to emergency stop the common arm drive motor. In addition, based on an output signal of the first encoder installed in the common arm driving motor and an output signal of the second encoder installed in the first arm driving motor, the first arm driving motor is controlled. Emergency stop while
When the second tip-side arm driving motor and the common arm driving motor are driven while the first tip-side arm driving motor is stopped to perform the extension and contraction of the arm, the second tip-side arm driving motor is When the encoder error occurs in which the first motor is used and the common arm driving motor is the second motor, the control unit applies a dynamic brake to the second tip arm driving motor to apply a dynamic brake to the second tip arm driving motor. The common arm is driven based on the output signal of the first encoder installed in the second front arm driving motor and the output signal of the second encoder installed in the common arm driving motor while emergency stopping the driving motor. Emergency stop while controlling the motor,
When the second tip-side arm driving motor and the common arm driving motor are driven while the first tip-side arm driving motor is stopped, the common arm driving motor is the first When the encoder error occurs in which the motor becomes a motor and the second front arm drive motor becomes the second motor, the control unit applies a dynamic brake to the common arm drive motor to emergency stop the common arm drive motor. In addition, based on an output signal of the first encoder installed in the common arm driving motor and an output signal of the second encoder installed in the second arm driving motor, the second tip-side arm driving motor is controlled. Industrial robot characterized in that the emergency stop while doing. The method according to any one of claims 1 to 3,
A hand rotation motor for rotating the hand with respect to the arm, and a hand encoder for detecting a rotation position of the hand rotation motor,
When the control of the hand rotation motor based on the detection result of the hand encoder becomes impossible during the extension and contraction of the arm is referred to as a second encoder error,
The control unit,
When the encoder error occurs during the extension and contraction of the arm to emergency stop the plurality of motors and the hand rotation motor during driving, the hand is based on the output signal of the first encoder and the output signal of the hand encoder. Emergency stop while controlling the rotating motor,
When the second encoder error occurs during the extension and contraction of the arm and emergency stop of the plurality of motors and the hand rotation motor during driving, a dynamic brake is applied to the hand rotation motor to emergency stop the hand rotation motor Together with the sikim, emergency stop of the plurality of motors during driving based on the output signal of the hand encoder and the output signal of the encoder,
When the encoder error and the second encoder error occur during the extension and contraction operation of the arm and emergency stop of the plurality of motors and the hand rotation motor during driving, a dynamic brake is applied to the first motor to stop the first motor. Emergency stop, applying a dynamic brake to the hand rotation motor to emergency stop the hand rotation motor, and to the output signal of the hand encoder, the output signal of the first encoder, and the output signal of the second encoder. Industrial robot, characterized in that the emergency stop while controlling the second motor based on. A hand, an arm rotatably connected to the distal end of the hand while having at least two arm parts rotatably connected to the hand, a body part rotatably connected to the base end of the arm, and the body part With respect to the arm drive mechanism for extending and contracting the arm in a horizontal direction,
The arm drive mechanism includes a plurality of motors for expanding and contracting the arm, and a plurality of encoders for detecting rotational positions of the plurality of motors,
Each of the plurality of encoders is a control method of a horizontal articulated industrial robot installed in each of the plurality of motors,
Control based on the detection result of the encoder becomes impossible in some of the motors among the plurality of motors that are being driven during the stretching and contracting operation of the arm, and the control based on the detection result of the encoder in the remaining motors When the encoder error is enabled, the motor during driving in which control based on the detection result of the encoder is disabled when the encoder error occurs is referred to as the first motor, and when the encoder error occurs. The motor during driving in which control based on the detection result of the encoder is enabled is referred to as a second motor, and the encoder installed in the first motor is referred to as a first encoder, and is installed in the second motor. Let the encoder be the second encoder,
When the encoder error occurs during the extension and contraction of the arm and emergency stops of the plurality of motors during driving, a dynamic brake is applied to the first motor to emergency stop the first motor, and the output of the first encoder Controlling the industrial robot, characterized in that the emergency stop while controlling the second motor based on a signal and an output signal of the second encoder.

Images