JP7784264B2 - Industrial robot and control method for industrial robot - Google Patents

Description

The present invention relates to an industrial robot that transports rectangular or square-shaped objects. The present invention also relates to a control method for such an industrial robot.

Conventionally, robots that transport glass substrates between cassettes are known (see, for example, Patent Document 1). The robot described in Patent Document 1 includes a horizontal movement unit, a robot hand unit, and a connecting unit that connects the horizontal movement unit to the robot hand unit. The horizontal movement unit includes a slider that moves left and right along a guide rail. The robot hand unit includes a first arm rotatably connected to the connecting unit, a second arm rotatably connected to the tip of the first arm, and a hand rotatably connected to the tip of the second arm and on which the glass substrate is mounted.

In the robot described in Patent Document 1, two first distance sensors are attached to the top surface of the hand to detect the distance to the front end face of the glass substrate. The two first distance sensors are arranged with a gap between them in the left-right direction. A position detection sensor is attached to the connecting part via a support arm to detect the position of the left end face of the glass substrate placed on the hand located at the origin position.

A control device is connected to the robot described in Patent Document 1. Based on the detection results of the two first distance sensors, the control device calculates a correction amount corresponding to the amount of deviation in the front-to-back direction of the glass substrate placed in the cassette from a reference position, and a correction amount corresponding to the amount of tilt of the glass substrate placed in the cassette from the reference position when viewed from the top-to-bottom direction. The control device also calculates a correction amount corresponding to the amount of deviation in the left-to-right direction of the glass substrate placed on the hand from the reference position based on the detection results of the position detection sensors.

The robot described in Patent Document 1 corrects the orientation and front-to-back position of the hand before loading a glass substrate placed in a cassette onto the hand, based on a correction amount corresponding to the amount of misalignment of the glass substrate in the front-to-back direction relative to a reference position and a correction amount corresponding to the amount of tilt of the glass substrate relative to the reference position. Furthermore, when the robot transports the glass substrate loaded on the hand into a cassette for the next process, it corrects the left-to-right position of the hand based on a correction amount corresponding to the amount of misalignment of the glass substrate in the left-to-right direction relative to the reference position.

Japanese Patent Application Publication No. 9-162257

The robot described in Patent Document 1 corrects the horizontal position and orientation of the glass substrate placed in a cassette before placing the glass substrate in the cassette for the next process. To do this, the orientation and position of the hand are corrected both when receiving and removing the glass substrate from the cassette, and when loading and handing over the glass substrate to the cassette for the next process. As a result, with this robot, there is a risk that the time required to transport glass substrates between cassettes will be long.

For example, if moving the hand while maintaining the corrected orientation when receiving and removing a glass substrate from a cassette could cause interference between the glass substrate loaded on the hand or the hand and the cassette components, it may be necessary to change the orientation of the hand before moving it out of the cassette to prevent interference between the glass substrate or hand and the cassette components. In this case, it will take longer to transport the glass substrate between cassettes.

The objective of the present invention is to provide an industrial robot that transports an object from a designated receiving section to a designated delivery section, and that can shorten the time it takes to transport the object from the receiving section to the delivery section, even if the horizontal position and orientation of the object placed in the receiving section can be corrected before placing the object in the delivery section.

Another object of the present invention is to provide a control method for an industrial robot that transports an object from a designated receiving section to a designated delivery section, which can shorten the time it takes to transport an object from the receiving section to the delivery section, even if the horizontal position and orientation of the object placed in the receiving section can be corrected before placing the object in the delivery section.

In order to solve the above problem, the industrial robot of the present invention is an industrial robot that transports rectangular or square-shaped objects, and is equipped with a hand on which the object can be placed and which can move horizontally, an arm to which the hand is connected, a main body to which the arm is connected so that it can rotate about the vertical axis, two optical first detection mechanisms attached to the hand, a second optical detection mechanism attached to the main body, and a control unit that controls the industrial robot, and the position of the hand when the tip of the hand moves away from the main body and the hand receives the object placed on a predetermined receiving unit is defined as a receiving position, and the position of the hand when the tip of the hand moves away from the main body and the hand receives the object is defined as a receiving position. When the position of the hand when the industrial robot delivers the object to a predetermined delivery section is defined as a delivery position, the industrial robot performs the following three actions: a first action, which is an action when the hand moves to a receiving position so that the tip of the hand moves away from the main body; a second action, which is an action when the hand that has received the object to be transported at the receiving position moves so that the tip of the hand approaches the main body; and a third action, which is an action when the hand with the object loaded thereon moves to the delivery position so that the tip of the hand moves away from the main body when the industrial robot performs the first action and the second action. The hand moves linearly while facing in a fixed direction relative to the main body when the industrial robot performs the first action and the second action, and the direction of movement of the hand when the industrial robot performs the first action and the second action is defined as a first direction, and a direction perpendicular to the first direction and the up-down direction is defined as a second direction. the first detection mechanism is a reflective detection mechanism including a first light-emitting unit and a first light-receiving unit that receives light emitted from the first light-emitting unit and reflected by the transport object, the two first detection mechanisms are arranged with a gap between them in the second direction, the second detection mechanism is a transmissive detection mechanism having a second light-receiving unit made of a line sensor or an area sensor, and a second light-emitting unit that is arranged facing the second light-receiving unit with a predetermined gap between it and the second light-receiving unit in the up-down direction, when the industrial robot performs a first operation, the two first detection mechanisms pass below the transport object placed on the receiving unit, and when the industrial robot performs a second operation, one end face in the second direction of the transport object mounted on the hand passes between the second light-receiving unit and the second light-emitting unit, and the control unit When the industrial robot performs a first operation, it acquires first position data, which is data on the position of the hand in the first direction when one of the two first detection mechanisms detects the transported object, and second position data, which is data on the position of the hand in the first direction when the other of the two first detection mechanisms detects the transported object; when the industrial robot performs a second operation, it acquires third position data, which is data on the position in the second direction of one end face of the transported object in the second direction detected by the second detection mechanism when the hand moves to a predetermined measurement position; and when the industrial robot performs a third operation, it corrects the horizontal position and orientation of the hand when it reaches the delivery position based on the first position data, second position data, and third position data.

In addition, to solve the above-mentioned problems, the control method of the present invention relates to an industrial robot including a hand that can move horizontally and that can carry a rectangular or square-shaped transport object, an arm to which the hand is connected, a main body to which the arm is rotatably connected, two first optical detection mechanisms attached to the hand, and a second optical detection mechanism attached to the main body, and defines a receiving position as the position of the hand when the tip of the hand moves away from the main body and the hand receives an object placed on a predetermined receiving section, and a delivery position as the position of the hand when the tip of the hand moves away from the main body and the hand delivers the object carried on the hand to a predetermined delivery section. When the hand is set to the receiving position, the hand performs a first action, which is an action when the hand moves to the receiving position so that the tip of the hand moves away from the main body, a second action, which is an action when the hand that has received the transport object at the receiving position moves so that the tip of the hand approaches the main body after the first action, and a third action, which is an action when the hand with the transport object loaded thereon moves to the delivery position so that the tip of the hand moves away from the main body after the second action, and the hand moves linearly while facing in a fixed direction relative to the main body when the first action and the second action are performed, and the direction of movement of the hand when the first action and the second action are performed is set to the first direction, and a direction perpendicular to the first direction and the up-down direction is set to the second direction, the first detection mechanism detects a first light emitting a first light-receiving unit that receives light emitted from the first light-emitting unit and reflected by the object to be transported, the two first detection mechanisms being arranged at an interval in a second direction, and the second detection mechanism being a transmission type detection mechanism having a second light-receiving unit consisting of a line sensor or an area sensor, and a second light-emitting unit that is arranged facing the second light-receiving unit with a predetermined interval between it and the second light-receiving unit in the up-down direction, wherein when a first operation is performed, the two first detection mechanisms pass below the object to be transported placed on the receiving unit, and when a second operation is performed, one end face in the second direction of the object to be transported mounted on the hand passes between the second light-receiving unit and the second light-emitting unit, When performing the second operation, the system acquires first position data, which is data on the position of the hand in the first direction when one of the two first detection mechanisms detects the transported object, and second position data, which is data on the position of the hand in the first direction when the other of the two first detection mechanisms detects the transported object; when performing the second operation, the system acquires third position data, which is data on the second direction position of one end face of the transported object in the second direction detected by the second detection mechanism when the hand moves to a predetermined measurement position; and when performing the third operation, the system corrects the horizontal position and orientation of the hand when it reaches the delivery position based on the first position data, second position data, and third position data.

In this invention, when the industrial robot performs the third operation, the horizontal position and orientation of the hand when it reaches the transfer position are corrected based on the first position data, second position data, and third position data. In other words, in this invention, the horizontal position and orientation of the hand are corrected only when performing the third operation, which is the operation in which the hand carrying the object to be transported moves to the transfer position so that the tip of the hand moves away from the main body, but the position and orientation of the hand are not corrected when performing the first operation, which is the operation in which the hand moves to the receiving position so that the tip of the hand moves away from the main body. Therefore, in this invention, even if the horizontal position and orientation of the object to be transported placed in the receiving section can be corrected before placing the object on the transfer section, it is possible to shorten the time it takes to transport the object from the receiving section to the transfer section.

In the present invention, for example, the arm is composed of multiple arm sections that are rotatably connected to each other and are capable of extending and retracting horizontally, the hand is rotatably connected to the tip end of the arm, and the base end of the arm is rotatably connected to the main body.

In the present invention, the industrial robot includes, for example, an arm drive mechanism that extends and retracts the arm so that the hand moves linearly relative to the main body while facing in a fixed direction, a rotation mechanism that rotates the main body, and a horizontal movement mechanism that moves the main body in a left-right direction perpendicular to the up-down direction; the hand moves linearly relative to the main body in a front-to-back direction perpendicular to the up-down and left-right directions when the industrial robot performs a third operation; and the control unit controls the arm drive mechanism, rotation mechanism, and horizontal movement mechanism based on the first position data, second position data, and third position data when the industrial robot performs the third operation to correct the horizontal position and orientation of the hand when it reaches the transfer position.

In the present invention, for example, the first direction and the left-right direction coincide, and the hand moves linearly left-right relative to the main body when the industrial robot performs the first and second operations. If the main body cannot be moved forward and backward, it may not be possible to properly correct the orientation of the hand when performing the first operation. However, in the present invention, even if the orientation of the hand cannot be properly corrected when performing the first operation, it is possible to properly correct the orientation of the hand when performing the third operation.

In the present invention, the first direction and the front-to-rear direction may coincide, and the hand may move linearly in the front-to-rear direction relative to the main body when the industrial robot performs the first operation and the second operation.

As described above, in an industrial robot that transports an object from a designated receiving section and then transfers it to a designated delivery section, the present invention makes it possible to shorten the transport time of the object from the receiving section to the delivery section, even if it is possible to correct the horizontal position and orientation of the object placed in the receiving section before placing it in the delivery section.

1 is a plan view of an industrial robot according to an embodiment of the present invention; 2 is a plan view of the industrial robot shown in FIG. 1 in a different state. FIG. 2 is a rear view of the industrial robot shown in FIG. 1 . FIG. 2 is a block diagram for explaining the configuration of the industrial robot shown in FIG. 1 . 10A and 10B are diagrams for explaining a method of calculating correction values for the horizontal position and orientation of the hand that are corrected when the industrial robot shown in FIG. 1 performs the third operation.

The following describes an embodiment of the present invention with reference to the drawings.

(Configuration of industrial robots)
Fig. 1 is a plan view of an industrial robot 1 according to an embodiment of the present invention. Fig. 2 is a plan view of the industrial robot 1 shown in Fig. 1 in a different state. Fig. 3 is a rear view of the industrial robot 1 shown in Fig. 1. Fig. 4 is a block diagram for explaining the configuration of the industrial robot 1 shown in Fig. 1.

The industrial robot 1 (hereinafter referred to as "robot 1") of this embodiment is a horizontal articulated robot that transports objects such as glass substrates 2 for organic EL displays or liquid crystal displays (hereinafter referred to as "substrates 2"). The substrates 2 are formed in the shape of a rectangular or square flat plate. The robot 1 transports the substrates 2 from, for example, storage cassettes 3 and 4 that store multiple substrates 2, to a processing device 5 that performs a predetermined process on the substrates 2. That is, the robot 1, for example, removes the substrates 2 from the storage cassettes 3 and 4, and transports the substrates 2 removed from the storage cassettes 3 and 4 into the processing device 5.

In the following description, the Y direction in Figure 1, etc., which is perpendicular to the up-down direction, will be referred to as the "left-right direction," and the X direction in Figure 1, etc., which is perpendicular to the up-down and left-right directions, will be referred to as the "front-to-back direction." Furthermore, the Y1 direction side in Figure 1, etc., which is one side of the left-to-right direction, will be referred to as the "right" side, and the Y2 direction side in Figure 1, etc., which is the opposite side, will be referred to as the "left" side. The X1 direction side in Figure 1, etc., which is one side of the front-to-back direction, will be referred to as the "front" side, and the X2 direction side in Figure 1, etc., which is the opposite side, will be referred to as the "rear" side.

Storage cassettes 3 and 4 store multiple substrates 2 stacked and spaced apart in the vertical direction. In this embodiment, storage cassette 3 is located in front of robot 1, and storage cassette 4 is located on the right side of robot 1. Furthermore, processing device 5 is located behind robot 1. The end faces of the substrates 2 stored in storage cassettes 3 and 4 and processing device 5 are approximately parallel to the front-to-back or left-to-right direction.

The robot 1 comprises two hands 6, 7 that can move horizontally and that carry a substrate 2; an arm 8 to which the hand 6 is connected; an arm 9 to which the hand 7 is connected; a main body 10 to which the arms 8, 9 are rotatably connected; a base 11 to which the main body 10 is rotatably connected; and a base 12 that holds the base 11 so that it can move linearly in the horizontal direction. The main body 10 comprises arm supports 15 that support the base ends of the arms 8, 9 and are movable up and down; a support frame 16 that supports the arm supports 15 so that they can be moved up and down; and a swivel frame 17 that forms the lower end of the main body 10.

Hand 6 is rotatably connected to the tip of arm 8 with the vertical direction as the axis of rotation, and hand 7 is rotatably connected to the tip of arm 9 with the vertical direction as the axis of rotation. Hand 7 is positioned below hand 6. Arm 8 is positioned above hand 6. Arm 9 is positioned below hand 7. The base ends of arms 8 and 9 are rotatably connected to main body 10 with the vertical direction as the axis of rotation. Specifically, the base ends of arms 8 and 9 are rotatably connected to arm support 15. When viewed from the vertical direction, the center of rotation of arm 8 relative to main body 10 and the center of rotation of arm 9 relative to main body 10 coincide.

The hands 6 and 7 each include a hand base 18 that is rotatably connected to the tip end of the arms 8 and 9, and a plurality of linear forks 19 on whose upper surface the substrate 2 is placed. In this embodiment, the hands 6 and 7 each include four forks 19. The four forks 19 protrude horizontally from the hand base 18 in the same direction. The four forks 19 are also arranged parallel to one another. The forks 19 of hand 6 and the forks 19 of hand 7 protrude in the same direction.

Arms 8 and 9 are multi-joint arms that extend and retract horizontally. They are comprised of a first arm portion 21 and a second arm portion 22 that are pivotally connected to each other. That is, arms 8 and 9 are comprised of two arms that are pivotally connected to each other and are capable of extending and retracting horizontally. The base end of first arm portion 21 is pivotally connected to main body portion 10 (specifically, arm support 15). The base end of second arm portion 22 is pivotally connected to the tip end of first arm portion 21. Hands 6 and 7 are pivotally connected to the tip end of second arm portion 22. In arm 8, second arm portion 22 is positioned below first arm portion 21, while in arm 9, second arm portion 22 is positioned above first arm portion 21.

The base end of arm 8 is rotatably connected to the upper end of arm support 15, and the base end of arm 9 is rotatably connected to the lower end of arm support 15. In the horizontal direction, the distance between the center of rotation of first arm portion 21 relative to arm support 15 and the center of rotation of second arm portion 22 relative to first arm portion 21 is equal to the distance between the center of rotation of second arm portion 22 relative to first arm portion 21 and the center of rotation of hands 6 and 7 relative to second arm portion 22.

Arms 8, 9 are horizontally extendable between a position where arms 8, 9 extend so that the tips of hands 6, 7 (i.e., the tips of forks 19) move away from (away from) main body 10, and a position where arms 8, 9 retract so that the tips of hands 6, 7 move closer to main body 10. When arms 8, 9 extend and retract equally relative to main body 10, hands 6 and 7 overlap vertically, and arms 8 and 9 overlap vertically.

The support frame 16 supports the hands 6, 7 and the arms 8, 9 via the arm supports 15 so that they can be raised and lowered. The support frame 16 includes a column-shaped first support frame 23 that supports the arm supports 15 so that they can be raised and lowered, and a column-shaped second support frame 24 that supports the first support frame 23 so that it can be raised and lowered. The swivel frame 17 is formed in a flat, approximately rectangular parallelepiped shape with a thin thickness in the vertical direction. The swivel frame 17 is also formed in a long, slender rectangular parallelepiped shape. The lower end of the second support frame 24 is fixed to the upper surface of the tip side of the swivel frame 17. The base end side of the swivel frame 17 is rotatably connected to the base 11 with the vertical direction as the axis of rotation. The swivel frame 17 is positioned above the base 11. The base 11 is capable of linear movement in the left-right direction relative to the base 12.

The robot 1 also includes an arm drive mechanism 27 that extends and retracts the arm 8, an arm drive mechanism 28 that extends and retracts the arm 9, a rotation mechanism 29 that rotates the main body 10, a lifting mechanism 30 that raises and lowers the hands 6, 7 and the arms 8, 9, a horizontal movement mechanism 31 that moves the main body 10 left and right together with the base 11, and a control unit 32 that controls the robot 1. The robot 1 transports the substrate 2 by a combination of the extension and retraction movements of the arms 8, 9, the lifting and lowering movements of the arms 8, 9, etc., and the rotation and horizontal movement of the main body 10.

The robot 1 also has two detection mechanisms 33 and one detection mechanism 34 for detecting the position of the substrate 2 placed on the hand 6, and two detection mechanisms 33 and one detection mechanism 34 for detecting the position of the substrate 2 placed on the hand 7. In other words, the robot 1 has four detection mechanisms 33 and two detection mechanisms 34. In this embodiment, the detection mechanism 33 is a first detection mechanism, and the detection mechanism 34 is a second detection mechanism.

The arm drive mechanism 27 includes a motor as a drive source, a power transmission mechanism that transmits the motor's power to the arm 8 and hand 6, and an encoder for detecting the amount of motor rotation. The motor is a servo motor and is controlled based on the detection results of the encoder. The arm drive mechanism 27 extends and retracts the arm 8 horizontally so that the hand 6 moves linearly with respect to the main body 10 while facing in a fixed direction. The arm drive mechanism 27 is electrically connected to the control unit 32. Specifically, the motor, encoder, etc. of the arm drive mechanism 27 are electrically connected to the control unit 32.

Like the arm drive mechanism 27, the arm drive mechanism 28 includes a motor as a drive source, a power transmission mechanism that transmits the motor's power to the arm 9 and hand 7, and an encoder for detecting the amount of motor rotation. The motor is a servo motor and is controlled based on the detection results of the encoder. The arm drive mechanism 28 extends and retracts the arm 9 horizontally so that the hand 7 moves linearly with respect to the main body 10 while facing in a fixed direction. The arm drive mechanism 28 is electrically connected to the control unit 32. Specifically, the motor, encoder, etc. of the arm drive mechanism 28 are electrically connected to the control unit 32.

The rotation mechanism 29 rotates the swivel frame 17 relative to the base 11, with the vertical direction as the rotation axis. That is, the rotation mechanism 29 rotates the arms 8 and 9 together with the main body 10, with the vertical direction as the rotation axis. The rotation mechanism 29 includes a motor as a drive source, a power transmission mechanism that transmits the motor's power to the swivel frame 17, and an encoder for detecting the amount of motor rotation. The motor is a servo motor, and is controlled based on the detection results of the encoder. The rotation mechanism 29 is electrically connected to the control unit 32. Specifically, the motor, encoder, etc. of the rotation mechanism 29 are electrically connected to the control unit 32.

The lifting mechanism 30 raises and lowers the first support frame 23 relative to the second support frame 24, and raises and lowers the arm support 15 relative to the first support frame 23. The lifting mechanism 30 includes a motor that raises and lowers the arm support 15 and the first support frame 23, a reducer that transmits the motor's power to the first support frame 23 and the arm support 15, and an encoder that detects the amount of motor rotation. The motor is a servo motor and is controlled based on the detection results of the encoder.

The lifting mechanism 30 is electrically connected to the control unit 32. Specifically, the motor, encoder, etc. of the lifting mechanism 30 are electrically connected to the control unit 32. Note that the robot 1 may be provided with separate lifting mechanisms: one for raising and lowering the arm support 15 relative to the first support frame 23, and another for raising and lowering the first support frame 23 relative to the second support frame 24.

The horizontal movement mechanism 31 moves the base 11 linearly in the left-right direction relative to the base 12. That is, the horizontal movement mechanism 31 moves the main body 10 and arms 8 and 9 linearly in the left-right direction together with the base 11. The horizontal movement mechanism 31 includes a motor as a drive source, a power transmission mechanism that transmits the motor's power to the base 11, and an encoder for detecting the amount of motor rotation. The motor is a servo motor and is controlled based on the detection results of the encoder. The horizontal movement mechanism 31 is electrically connected to the control unit 32. Specifically, the motor, encoder, etc. of the horizontal movement mechanism 31 are electrically connected to the control unit 32.

The detection mechanism 33 is an optical detection mechanism. The detection mechanism 33 is also a reflective detection mechanism having a light-emitting unit 37 and a light-receiving unit 38 that receives light emitted from the light-emitting unit 37 and reflected by the substrate 2. The detection mechanisms 33 are attached to each of the hands 6 and 7. Specifically, two detection mechanisms 33 are attached to the hand 6, and two detection mechanisms 33 are attached to the hand 7. The detection mechanisms 33 are electrically connected to the control unit 32. In this embodiment, the light-emitting unit 37 is a first light-emitting unit, and the light-receiving unit 38 is a first light-receiving unit.

The detection mechanism 33 is attached to the hands 6, 7 so that the light-emitting surface of the light-emitting unit 37 and the light-receiving surface of the light-receiving unit 38 face upward. The detection mechanism 33 is also attached to the upper surfaces of the forks 19. In this embodiment, the detection mechanism 33 is attached to the two forks 19 that are located on the inside in a direction perpendicular to the longitudinal direction of the forks 19, out of the four forks 19 that each hand 6, 7 has. The detection mechanism 33 is also attached to the tip side of the forks 19.

The two detection mechanisms 33 attached to each of the hands 6 and 7 are arranged at the same position in the longitudinal direction of the forks 19. The two detection mechanisms 33 attached to each of the hands 6 and 7 are arranged with a gap between them in a direction perpendicular to the longitudinal direction of the forks 19. The detection mechanisms 33 may be attached to the two forks 19 that are located on the outer sides in the direction perpendicular to the longitudinal direction of the forks 19, out of the four forks 19 that each of the hands 6 and 7 has. The detection mechanisms 33 may also be attached to the base ends of the forks 19.

The detection mechanism 34 is an optical detection mechanism. The detection mechanism 34 is also a transmission-type detection mechanism having a light-emitting unit 39 and a light-receiving unit 40 arranged opposite the light-emitting unit 39. The light-emitting unit 39 is arranged opposite the light-receiving unit 40 with a predetermined gap between them in the vertical direction. In this embodiment, the light-receiving unit 40 is a line sensor. The light-receiving unit 40 has multiple light-receiving elements arranged in a line. The detection mechanism 34 is electrically connected to the control unit 32. In this embodiment, the light-emitting unit 39 is a second light-emitting unit, and the light-receiving unit 40 is a second light-receiving unit.

The detection mechanism 34 is attached to the main body 10. Specifically, the detection mechanism 34 is fixed to a sensor fixing member 42 that is fixed to the arm support 15, and is fixed to the arm support 15 via the sensor fixing member 42. In this embodiment, a detection mechanism 34 for detecting the position of the substrate 2 mounted on the hand 6 and a detection mechanism 34 for detecting the position of the substrate 2 mounted on the hand 7 are fixed to the arm support 15 via the sensor fixing member 42. In other words, two detection mechanisms 34 are fixed to the arm support 15. The two detection mechanisms 34 overlap in the vertical direction.

The detection mechanism 34 rotates together with the arm support 15 and moves up and down together with the arm support 15. As described above, the light receiving unit 40 has multiple light receiving elements arranged in a row. Specifically, when the longitudinal direction of the fork 19 and the front-to-rear direction are aligned, the multiple light receiving elements are arranged in a row in the left-to-right direction in the light receiving unit 40; and when the longitudinal direction of the fork 19 and the left-to-right direction are aligned, the multiple light receiving elements are arranged in a row in the front-to-rear direction in the light receiving unit 40.

As described above, the robot 1 transports the substrates 2 from the storage cassettes 3, 4 to the processing device 5. Also, as described above, the arms 8, 9 are horizontally extendable between an extended position where the arms 8, 9 extend so that the tips of the hands 6, 7 move away from the main body 10, and a retracted position where the arms 8, 9 move so that the tips of the hands 6, 7 move closer to the main body 10. In this embodiment, when the robot 1 receives the substrates 2 from the storage cassettes 3, 4 and when the robot 1 delivers the substrates 2 to the processing device 5, the arms 8, 9 are extended and the tips of the hands 6, 7 move away from the main body 10.

Let us assume that the position of the hand 6 (the position shown in Figure 1) when the tip of the hand 6 has moved away from the main body 10 (i.e., the arm 8 is extended) and the hand 6 receives the substrate 2 placed in the storage cassette 3 and loads it onto the hand 6 as hand position 6A, and the position of the hand 6 when the tip of the hand 6 has moved away from the main body 10 (i.e., the arm 8 is extended) and the hand 6 is handed over to the processing device 5 as hand position 6B. The robot 1 performs operation M11, in which the hand 6 moves to hand position 6A so that the tip of the hand 6 moves away from the main body 10; operation M12, in which, after operation M11, the hand 6 receives the substrate 2 at hand position 6A and moves so that the tip of the hand 6 approaches the main body 10; and operation M13, in which, after operation M12, the hand 6 with the substrate 2 loaded moves to hand position 6B so that the tip of the hand 6 moves away from the main body 10. In actions M11 and M13, the retracted arm 8 extends, and in action M12, the extended arm 8 retracts.

Furthermore, if the position of the hand 6 (the position shown in FIG. 2) when the tip of the hand 6 moves away from the main body 10 and loads and receives the substrate 2 placed in the storage cassette 4 onto the hand 6 is defined as hand position 6C, the robot 1 performs operation M14, in which the hand 6 moves to hand position 6C so that the tip of the hand 6 moves away from the main body 10; operation M15, after operation M14, in which the hand 6 receives the substrate 2 at hand position 6C and moves so that the tip of the hand 6 approaches the main body 10; and operation M16, after operation M15, in which the hand 6 with the substrate 2 loaded moves to hand position 6B so that the tip of the hand 6 moves away from the main body 10. In operations M14 and M16, the retracted arm 8 extends, and in operation M15, the extended arm 8 retracts.

Similarly, if the position of the hand 7 when the tip of the hand 7 has moved away from the main body 10 (i.e., the arm 9 is extended) and the hand 7 receives the substrate 2 placed in the storage cassette 3 by loading it onto the hand 7, the position of the hand 7 is defined as hand position 7A, and the position of the hand 7 when the tip of the hand 7 has moved away from the main body 10 (i.e., the arm 9 is extended) and the hand 7 delivers the substrate 2 loaded on the hand 7 to the processing device 5, the robot 1 performs operation M21, which is an operation in which the hand 7 moves to hand position 7A so that the tip of the hand 7 moves away from the main body 10; operation M22, which is an operation in which the hand 7, having received the substrate 2 at hand position 7A, moves so that the tip of the hand 7 approaches the main body 10 after operation M21; and operation M23, which is an operation in which the hand 7 with the substrate 2 loaded thereon moves to hand position 7B so that the tip of the hand 7 moves away from the main body 10 after operation M22. In actions M21 and M23, the retracted arm 9 extends, and in action M22, the extended arm 9 retracts.

Furthermore, if the position of the hand 7 when the tip of the hand 7 moves away from the main body 10 and loads and receives the substrate 2 placed in the storage cassette 4 onto the hand 7 is defined as hand position 7C, the robot 1 performs operation M24, in which the hand 7 moves to hand position 7C so that the tip of the hand 7 moves away from the main body 10; operation M25, after operation M24, in which the hand 7 receives the substrate 2 at hand position 7C and moves so that the tip of the hand 7 approaches the main body 10; and operation M26, after operation M25, in which the hand 7 with the substrate 2 loaded moves to hand position 7B so that the tip of the hand 7 moves away from the main body 10. In operations M24 and M26, the retracted arm 9 extends, and in operation M25, the extended arm 9 retracts.

When operations M12 and M15 are completed, the rotation radius (turning radius) of the main body 10, including the substrate 2 loaded on the hand 6, the hand 6, and the arm 8, is minimized. Similarly, when operations M22 and M25 are completed, the rotation radius of the main body 10, including the substrate 2 loaded on the hand 7, the hand 7, and the arm 9, is minimized.

As described above, the arm drive mechanism 27 extends and retracts the arm 8 so that the hand 6 moves linearly while facing a fixed direction relative to the main body 10, and the arm drive mechanism 28 extends and retracts the arm 9 so that the hand 7 moves linearly while facing a fixed direction relative to the main body 10. In other words, when the robot 1 performs operations M11 to M16, the hand 6 moves linearly while facing a fixed direction relative to the main body 10, and when the robot 1 performs operations M21 to M26, the hand 7 moves linearly while facing a fixed direction relative to the main body 10.

In this embodiment, the storage cassette 3 is located in front of the robot 1, the storage cassette 4 is located to the right of the robot 1, and the processing device 5 is located behind the robot 1. Therefore, the hand 6 moves linearly in the front-to-back direction relative to the main body 10 when the robot 1 performs operations M11 to M13 and M16, and moves linearly in the left-to-right direction relative to the main body 10 when the robot 1 performs operations M14 and M15. Furthermore, the hand 7 moves linearly in the front-to-back direction relative to the main body 10 when the robot 1 performs operations M21 to M23 and M26, and moves linearly in the left-to-right direction relative to the main body 10 when the robot 1 performs operations M24 and M25.

Specifically, when the robot 1 performs operation M11, the hand 6 moves linearly forward relative to the main body 10 with the tips of the forks 19 facing forward; when the robot 1 performs operation M12, the hand 6 moves linearly backward relative to the main body 10 with the tips of the forks 19 facing forward; when the robot 1 performs operation M14, the hand 6 moves linearly to the right relative to the main body 10 with the tips of the forks 19 facing right; when the robot 1 performs operation M15, the hand 6 moves linearly to the left relative to the main body 10 with the tips of the forks 19 facing right; and when the robot 1 performs operations M13 and M16, the hand 6 moves linearly backward relative to the main body 10 with the tips of the forks 19 facing backward.

Similarly, when the robot 1 performs operation M21, the hand 7 moves linearly forward relative to the main body 10 with the tips of the forks 19 facing forward; when the robot 1 performs operation M22, the hand 7 moves linearly backward relative to the main body 10 with the tips of the forks 19 facing forward; when the robot 1 performs operation M24, the hand 7 moves linearly to the right relative to the main body 10 with the tips of the forks 19 facing right; when the robot 1 performs operation M25, the hand 7 moves linearly to the left relative to the main body 10 with the tips of the forks 19 facing right; and when the robot 1 performs operations M23 and M26, the hand 7 moves linearly backward relative to the main body 10 with the tips of the forks 19 facing backward.

When robot 1 performs operation M11, the two detection mechanisms 33 attached to hand 6 pass below the substrate 2 placed in storage cassette 3 (specifically, below the substrate 2 loaded onto hand 6 after operation M11), and when robot 1 performs operation M21, the two detection mechanisms 33 attached to hand 7 pass below the substrate 2 placed in storage cassette 3 (specifically, below the substrate 2 loaded onto hand 7 after operation M21).

When robot 1 performs operation M14, the two detection mechanisms 33 attached to hand 6 pass below the substrate 2 placed in storage cassette 4 (specifically, below the substrate 2 loaded onto hand 6 after operation M14), and when robot 1 performs operation M24, the two detection mechanisms 33 attached to hand 7 pass below the substrate 2 placed in storage cassette 4 (specifically, below the substrate 2 loaded onto hand 7 after operation M24).

When the robot 1 performs operation M12, one left-right end surface of the board 2 mounted on the hand 6 passes between the light-emitting unit 39 and the light-receiving unit 40 of one of the two detection mechanisms 34, and when the robot 1 performs operation M22, one left-right end surface of the board 2 mounted on the hand 7 passes between the light-emitting unit 39 and the light-receiving unit 40 of the other detection mechanism 34. In this embodiment, when the robot 1 performs operations M12 and M22, the detection mechanism 34 is positioned to the right of the hands 6 and 7, and the right end surface of the board 2 mounted on the hands 6 and 7 passes between the light-emitting unit 39 and the light-receiving unit 40.

When robot 1 performs operation M15, one front-to-rear end surface of the substrate 2 mounted on hand 6 passes between the light-emitting unit 39 and light-receiving unit 40 of one of the two detection mechanisms 34, and when robot 1 performs operation M25, one front-to-rear end surface of the substrate 2 mounted on hand 7 passes between the light-emitting unit 39 and light-receiving unit 40 of the other detection mechanism 34. In this embodiment, when robot 1 performs operations M15 and M25, the detection mechanism 34 is positioned behind the hands 6 and 7, and the rear end surface of the substrate 2 mounted on hands 6 and 7 passes between the light-emitting unit 39 and light-receiving unit 40.

That is, the detection mechanism 34 is positioned so that the right end surface of the board 2 mounted on the hands 6 and 7 passes between the light-emitting unit 39 and the light-receiving unit 40 when the robot 1 performs operations M12 and M22, and so that the rear end surface of the board 2 mounted on the hands 6 and 7 passes between the light-emitting unit 39 and the light-receiving unit 40 when the robot 1 performs operations M15 and M25. Furthermore, the detection mechanism 34 is positioned behind the rear end surface of the board 2 mounted on the hands 6 and 7 positioned at hand positions 6A and 7A, and to the left of the left end surface of the board 2 mounted on the hands 6 and 7 positioned at hand positions 6C and 7C. Furthermore, the detection mechanism 34 is positioned between the front and rear end surfaces of the board 2 mounted on the hands 6 and 7 after operations M12 and M22 are completed, in the front-to-back direction, and between the right and left end surfaces of the board 2 mounted on the hands 6 and 7 after operations M15 and M25 are completed, in the left-to-right direction.

As described above, the light receiving unit 40 is a line sensor in which multiple light receiving elements are arranged in a row, making it possible for the detection mechanism 34 to detect the left-right position of the right end surface of the board 2 placed on the hands 6 and 7 after operations M12 and M22 are completed. Furthermore, it is possible for the detection mechanism 34 to detect the front-to-back position of the rear end surface of the board 2 placed on the hands 6 and 7 after operations M15 and M25 are completed.

The robot 1 performs a rotational movement to rotate the main body 10 between operations M12 and M13, and between operations M15 and M16. At this time, the arm 9 is also retracted. The robot 1 also performs a rotational movement to rotate the main body 10 between operations M22 and M23, and between operations M25 and M26. At this time, the arm 8 is also retracted. The robot 1 also raises and lowers the arm support 15 and moves the main body 10 left and right, as necessary, between operations M12 and M13, between operations M15 and M16, between operations M22 and M23, and between operations M25 and M26. The robot 1 may also raise and lower the arm support 15 and move the main body 10 left and right when performing operations M11 to M16 and M21 to M26, as necessary.

(Robot control method)
When the robot 1 performs operation M11, the control unit 32 acquires position data D1, which is data on the front-to-rear position of the hand 6 when one of the two detection mechanisms 33 attached to the hand 6 detects the substrate 2 (specifically, when one detection mechanism 33 detects the rear end surface of the substrate 2 placed in the storage cassette 3 (i.e., when one detection mechanism 33 first detects the substrate 2)), and position data D2, which is data on the front-to-rear position of the hand 6 when the other detection mechanism 33 detects the substrate 2 (specifically, when the other detection mechanism 33 detects the rear end surface of the substrate 2 placed in the storage cassette 3 (i.e., when the other detection mechanism 33 first detects the substrate 2)). The control unit 32 acquires the position data D1 and D2 based on the detection results of the detection mechanisms 33 and the detection results of the encoder of the arm drive mechanism 27.

Based on the position data D1 and D2, the control unit 32 determines the front-to-rear position and orientation (tilt of the substrate 2 in the horizontal plane) of the substrate 2 placed in the storage cassette 3. The control unit 32 also compares the determined front-to-rear position and orientation of the substrate 2 with the front-to-rear position and orientation of the substrate 2 previously taught to the robot 1, and corrects the front-to-rear position and orientation of the hand 6 when it reaches hand position 6A based on the comparison results when the robot 1 performs operation M11. In other words, based on the position data D1 and D2, the control unit 32 corrects the front-to-rear position and orientation of the hand 6 when it reaches hand position 6A when the robot 1 performs operation M11.

Specifically, when the robot 1 performs operation M11, the control unit 32 controls the arm drive mechanism 27, the rotation mechanism 29, and the horizontal movement mechanism 31 based on the position data D1 and D2 to correct the front-to-rear position and orientation of the hand 6 when it reaches hand position 6A. Furthermore, when the robot 1 performs operation M11, the control unit 32 corrects the front-to-rear position and orientation of the hand 6 when it reaches hand position 6A based on the position data D1 and D2 so that the front-to-rear position of the substrate 2 placed on the hand 6 is appropriate and the orientation of the substrate 2 placed on the hand 6 is appropriate.

In addition, when the robot 1 performs operation M12, the control unit 32 acquires position data D3, which is data on the left-right position of the right end surface of the substrate 2 detected by the detection mechanism 34 when the hand 6 moves to a predetermined measurement position. The control unit 32 acquires position data D3 based on the detection results of the detection mechanism 34 and the detection results of the encoder of the arm drive mechanism 27. In this embodiment, for example, the measurement position is the position of the hand 6 when operation M12 is completed, but the measurement position may also be a predetermined position of the hand 6 while performing operation M12.

The control unit 32 determines the left-right position of the substrate 2 placed on the hand 6 based on the position data D3. The control unit 32 also compares the determined left-right position of the substrate 2 with the left-right position of the substrate 2 previously taught to the robot 1, and corrects the left-right position of the hand 6 when it reaches hand position 6B based on the comparison result when the robot 1 performs operation M13. In other words, the control unit 32 corrects the left-right position of the hand 6 when it reaches hand position 6B based on the position data D3 when the robot 1 performs operation M13.

Specifically, when the robot 1 performs operation M13, the control unit 32 controls the horizontal movement mechanism 31 based on the position data D3 to correct the left-right position of the hand 6 when it reaches hand position 6B. Furthermore, when the robot 1 performs operation M13, the control unit 32 corrects the left-right position of the hand 6 when it reaches hand position 6B based on the position data D3 so that the left-right position of the substrate 2 placed on the processing device 5 is appropriate.

Similarly, when the robot 1 performs operation M21, the control unit 32 acquires position data D4, which is data on the front-to-rear position of the hand 7 when one of the two detection mechanisms 33 attached to the hand 7 detects the substrate 2, and position data D5, which is data on the front-to-rear position of the hand 7 when the other detection mechanism 33 detects the substrate 2. The control unit 32 acquires the position data D4 and D5 based on the detection results of the detection mechanisms 33 and the detection results of the encoder of the arm drive mechanism 28.

The control unit 32 determines the front-to-rear position and orientation of the substrate 2 placed in the storage cassette 3 based on the position data D4 and D5. The control unit 32 also compares the determined front-to-rear position and orientation of the substrate 2 with the front-to-rear position and orientation of the substrate 2 previously taught to the robot 1, and, when the robot 1 performs operation M21, corrects the front-to-rear position and orientation of the hand 7 when it reaches hand position 7A based on the comparison result.

Specifically, when the robot 1 performs operation M21, the control unit 32 controls the arm drive mechanism 28, the rotation mechanism 29, and the horizontal movement mechanism 31 based on the position data D4 and D5 to correct the front-to-rear position and orientation of the hand 7 when it reaches hand position 7A. Furthermore, when the robot 1 performs operation M21, the control unit 32 corrects the front-to-rear position and orientation of the hand 7 when it reaches hand position 7A based on the position data D4 and D5 so that the front-to-rear position of the substrate 2 placed on the hand 7 is appropriate and the orientation of the substrate 2 placed on the hand 7 is appropriate.

In addition, when the robot 1 performs operation M22, the control unit 32 acquires position data D6, which is data on the left-right position of the right end surface of the substrate 2 detected by the detection mechanism 34 when the hand 7 moves to a predetermined measurement position. The control unit 32 acquires position data D6 based on the detection results of the detection mechanism 34 and the detection results of the encoder of the arm drive mechanism 28. In this embodiment, for example, the measurement position is the position of the hand 7 when operation M22 is completed, but the measurement position may also be a predetermined position of the hand 7 while operation M22 is being performed.

The control unit 32 determines the left-right position of the substrate 2 placed on the hand 7 based on the position data D6. The control unit 32 also compares the determined left-right position of the substrate 2 with the left-right position of the substrate 2 previously taught to the robot 1, and corrects the left-right position of the hand 7 when it reaches hand position 7B based on the comparison result when the robot 1 performs operation M23. In other words, the control unit 32 corrects the left-right position of the hand 7 when it reaches hand position 7B based on the position data D6 when the robot 1 performs operation M23.

Specifically, when the robot 1 performs operation M23, the control unit 32 controls the horizontal movement mechanism 31 based on the position data D6 to correct the left-right position of the hand 7 when it reaches hand position 7B. Furthermore, when the robot 1 performs operation M23, the control unit 32 corrects the left-right position of the hand 7 when it reaches hand position 7B based on the position data D6 so that the left-right position of the substrate 2 placed on the processing device 5 is appropriate.

In addition, when the robot 1 performs operation M14, the control unit 32 acquires position data D11, which is data on the left-right position of the hand 6 when one of the two detection mechanisms 33 attached to the hand 6 detects the substrate 2 (specifically, when one detection mechanism 33 detects the left end surface of the substrate 2 placed in the storage cassette 4), and position data D12, which is data on the left-right position of the hand 6 when the other detection mechanism 33 detects the substrate 2 (specifically, when the other detection mechanism 33 detects the left end surface of the substrate 2 placed in the storage cassette 4). In addition, when the robot 1 performs operation M15, the control unit 32 acquires position data D13, which is data on the front-to-rear position of the rear end surface of the substrate 2 detected by the detection mechanism 34 when the hand 6 moves to a predetermined measurement position.

In this embodiment, for example, the position of the hand 6 when operation M15 is completed is the measurement position. However, the measurement position may also be a predetermined position of the hand 6 while operation M15 is being performed. Furthermore, the control unit 32 acquires position data D11 and D12 based on the detection results of the detection mechanism 33 and the encoder of the arm drive mechanism 27, and acquires position data D13 based on the detection results of the detection mechanism 34 and the encoder of the arm drive mechanism 27. Note that when the robot 1 performs operation M14 and places the substrate 2 placed in the storage cassette 4 on the hand 6, the arm 8 is extended so that the hand 6 is positioned at the pre-taught hand position 6C. The hand 6 is loaded with the substrate 2 in the same state (position and orientation) as it was in the storage cassette 4.

The control unit 32 determines the front-rear and left-right positions and orientation of the substrate 2 placed on the hand 6 based on the position data D11 to D13. The control unit 32 also compares the determined front-rear and left-right positions (horizontal position) and orientation of the substrate 2 with the horizontal position and orientation of the substrate 2 previously taught to the robot 1, and corrects the horizontal position and orientation of the hand 6 when it reaches hand position 6B based on the comparison results when the robot 1 performs operation M16. In other words, the control unit 32 corrects the horizontal position and orientation of the hand 6 when it reaches hand position 6B based on the position data D11 to D13 when the robot 1 performs operation M16.

Specifically, when the robot 1 performs operation M16, the control unit 32 controls the arm drive mechanism 27, the rotation mechanism 29, and the horizontal movement mechanism 31 based on the position data D11 to D13 to correct the horizontal position and orientation of the hand 6 when it reaches hand position 6B. Furthermore, when the robot 1 performs operation M16, the control unit 32 corrects the horizontal position and orientation of the hand 6 when it reaches hand position 6B based on the position data D11 to D13 so that the horizontal position of the substrate 2 placed on the processing device 5 is appropriate and the orientation of the substrate 2 placed on the processing device 5 is appropriate.

Similarly, when the robot 1 performs operation M24, the control unit 32 acquires position data D14, which is data on the left-right position of the hand 7 when one of the two detection mechanisms 33 attached to the hand 7 detects the substrate 2, and position data D15, which is data on the left-right position of the hand 7 when the other detection mechanism 33 detects the substrate 2. Also, when the robot 1 performs operation M25, the control unit 32 acquires position data D16, which is data on the front-to-back position of the rear end surface of the substrate 2 detected by the detection mechanism 34 when the hand 7 moves to a predetermined measurement position.

In this embodiment, for example, the position of the hand 7 when operation M25 is completed is the measurement position, but the measurement position may also be a predetermined position of the hand 7 while operation M25 is being performed. Furthermore, the control unit 32 acquires position data D14 and D15 based on the detection results of the detection mechanism 33 and the encoder of the arm drive mechanism 28, and acquires position data D16 based on the detection results of the detection mechanism 34 and the encoder of the arm drive mechanism 28. After the robot 1 performs operation M24, when it places the substrate 2 placed in the storage cassette 4 on the hand 7, the arm 9 is extended so that the hand 7 is positioned at the pre-taught hand position 7C. The substrate 2 placed on the hand 7 is in the same state (position and orientation) as it was in the storage cassette 4.

The control unit 32 determines the front-rear and left-right positions and orientation of the substrate 2 placed on the hand 7 based on the position data D14 to D16. The control unit 32 also compares the determined front-rear and left-right positions (horizontal position) and orientation of the substrate 2 with the horizontal position and orientation of the substrate 2 previously taught to the robot 1, and corrects the horizontal position and orientation of the hand 7 when it reaches hand position 7B based on the comparison results when the robot 1 performs operation M26. In other words, the control unit 32 corrects the horizontal position and orientation of the hand 7 when it reaches hand position 7B based on the position data D14 to D16 when the robot 1 performs operation M26.

Specifically, when the robot 1 performs operation M26, the control unit 32 controls the arm drive mechanism 28, the rotation mechanism 29, and the horizontal movement mechanism 31 based on the position data D14 to D16 to correct the horizontal position and orientation of the hand 7 when it reaches hand position 7B. Furthermore, when the robot 1 performs operation M26, the control unit 32 corrects the horizontal position and orientation of the hand 7 when it reaches hand position 7B based on the position data D14 to D16 so that the horizontal position of the substrate 2 placed on the processing device 5 is appropriate and the orientation of the substrate 2 placed on the processing device 5 is appropriate.

In this embodiment, the storage cassette 4 is a receiving section, the processing device 5 is a delivery section, hand positions 6C and 7C are receiving positions, and hand positions 6B and 7B are delivery positions. Furthermore, operations M14 and M24 are first operations, operations M15 and M25 are second operations, and operations M16 and M26 are third operations. Furthermore, in this embodiment, the left-right direction (Y direction) is the first direction in which the hands 6 and 7 move when the robot 1 performs operations M14 and M24, which are the first operations, and the front-back direction (X direction) is the second direction perpendicular to the up-down direction and the first direction. When the robot 1 performs operations M14, M15, M24, and M25, the two detection mechanisms 33 attached to the hand 6 and the two detection mechanisms 33 attached to the hand 7 are spaced apart in the front-back direction.

(How to calculate hand correction value)
FIG. 5 is a diagram for explaining a method for calculating correction values for the horizontal positions and orientations of the hands 6 and 7 that are corrected when the robot 1 shown in FIG. 1 performs the actions M16 and M26.

For example, if the substrate 2 is placed in the storage cassette 4 as shown by the solid lines in Figure 5, the correction values for the front-to-back and left-to-right positions and orientations of the hands 6 and 7 that are corrected when the robot 1 performs operations M16 and M26 are calculated as follows. Note that in Figure 5, the substrate 2 shown by the dashed lines is the substrate 2 placed in the correct position in the storage cassette 4 (i.e., the substrate 2 placed so that there is no need to correct its horizontal position or orientation). Below, when distinguishing between the substrate 2 shown by the solid lines and the substrate 2 shown by the dashed lines in Figure 5, the substrate 2 shown by the solid lines will be referred to as substrate 2A, and the substrate 2 shown by the dashed lines will be referred to as substrate 2B. Furthermore, the center of substrate 2B when viewed from the top-to-bottom direction will be referred to as the origin OR.

When the robot 1 performs operations M14 and M24, the position of the left end surface of the substrate 2B detected by one of the two detection mechanisms 33 attached to the hands 6 and 7 is defined as PB1, the position of the left end surface of the substrate 2B detected by the other detection mechanism 33 attached to the hands 6 and 7 is defined as PB2, and when the robot 1 performs operations M15 and M25, the position of the rear end surface of the substrate 2B detected by the detection mechanism 34 is defined as PB3. In a coordinate system with the origin OR as the origin, the coordinates of PB1 to PB3 are expressed as follows:
PB1 (-b3/2, -YB/2)
PB2 (b3/2, -YB/2)
PB3 (-XB/2, b4-YB/2)

Here, XB is the width of the substrate 2 in the front-to-rear direction, and YB is the width of the substrate 2 in the left-to-right direction. Furthermore, b3 is the distance between PB1 and PB2 in the front-to-rear direction (i.e., the distance between the two detection mechanisms 33 in the front-to-rear direction), and the distance between the origin OR and PB1 in the front-to-rear direction is equal to the distance between the origin OR and PB2 in the front-to-rear direction. Furthermore, b4 is the distance between the left end surface of the substrate 2 and PB3 in the left-to-right direction.

Furthermore, when the robot 1 performs operations M14 and M24, the position of the left end surface of the substrate 2A detected by one of the two detection mechanisms 33 attached to the hands 6 and 7 is defined as P1, the position of the left end surface of the substrate 2A detected by the other detection mechanism 33 attached to the hands 6 and 7 is defined as P2, and when the robot 1 performs operations M15 and M25, the position of the rear end surface of the substrate 2A detected by the detection mechanism 34 is defined as P3. In a coordinate system with the origin OR as the origin, the coordinates of P1 to P3 are expressed as follows:
P1 (-b3/2, -YB/2+S1)
P2 (b3/2, -YB/2+S2)
P3 (-XB/2-S3, b4-YB/2)
Here, S1 is the distance between PB1 and P1 in the left-right direction, S2 is the distance between PB2 and P2 in the left-right direction, and S3 is the distance between PB3 and P3 in the front-rear direction.

If the position of the left rear corner of the substrate 2B is the origin WOR, in a coordinate system with the origin WOR as the origin, a line passing through P1 and P2 is expressed as follows:
ax+by+c=0
If the coordinates of P3 are (X0, Y0), the distance L between this line and P3 is:
L=|aX0+bY0+c|/(a ² + b ² ) ^1/2
This becomes:
Furthermore, if the position of the substrate 2B corresponding to P3 on the substrate 2A is P3', the coordinates of P3' are expressed as follows in a coordinate system with the origin OR as the origin:
P3' (-XB/2, L-YB/2)

If the tilt angle of the substrate 2A with respect to the substrate 2B (i.e., the deviation in the orientation of the substrate 2A with respect to the substrate 2B) is θ, then:
tanθ=(S2-S1)/b3
Therefore, the angle θ, which is the correction value for the orientation of the substrate 2A relative to the substrate 2B, is calculated by the following formula.
θ=tanθ ^-1 ((S2-S1)/b3)
This angle θ is the correction value for the orientation of the hands 6 and 7 when the robot 1 performs the actions M16 and M26.

In a coordinate system with the origin OR as the origin, if P3' is rotated by an angle θ, the rotated position is P3'r, the coordinates of P3'r are (P3'rx, P3'ry) and the coordinates of P3' are (P3'x, P3'y), then P3'rx, P3'rx, are expressed by the following equations.
P3'rx=P3'x×cosθ-P3'y×sinθ
P3'ry=P3'x×sinθ+P3'y×cosθ

In a coordinate system with the origin OR as the origin, if the coordinates of P3 are (P3x, P3y), then in order to calculate the parallel deviation component ΔX between P3 and P3'r and the parallel deviation component ΔY between P3 and P3'r, the coordinates of P3 (P3xr, P3yr) and the coordinates of P3'r (P3'rxr, P3'ryr) can be expressed as follows in a coordinate system rotated by an angle θ around the origin OR:
P3'rxr=P3'rx×cosθ+P3’ry×sinθ
P3'ryr=-P3'rx×sinθ+P3'ry×cosθ
P3xr=P3x×cosθ+P3y×sinθ
P3yr=-P3x×sinθ+P3y×cosθ

Therefore, the parallel deviation components ΔX and ΔY, which are correction values for the substrate 2A relative to the substrate 2B, are calculated by the following equations.
ΔX=P3xr-P3'rxr
ΔY=P3yr−P3′ryr
The parallel deviation component ΔX is a correction value for the positions of the hands 6 and 7 corrected by the horizontal drive mechanism 31 when the robot 1 performs operations M16 and M26. The parallel deviation component ΔY is a correction value for the positions of the hands 6 and 7 corrected by the arm drive mechanisms 27 and 28 when the robot 1 performs operations M16 and M26.

When the robot 1 performs operations M16 and M26, the angle θ is corrected by the rotation mechanism 29, the parallel deviation component ΔX is corrected by the horizontal movement mechanism 31, and the parallel deviation component ΔY is corrected by the arm drive mechanisms 27 and 28.

(Main effects of this embodiment)
As described above, in this embodiment, when the robot 1 performs operation M16, the control unit 32 corrects the horizontal position and orientation of the hand 6 when it reaches hand position 6B based on the position data D11 to D13, and when the robot 1 performs operation M26, the control unit 32 corrects the horizontal position and orientation of the hand 7 when it reaches hand position 7B based on the position data D14 to D16.

In other words, in this embodiment, the control unit 32 corrects the horizontal position and orientation of the hands 6 and 7 only when the robot 1 performs operations M16 and M26, and does not correct the position or orientation of the hands 6 and 7 when performing operations M14 and M24. Therefore, in this embodiment, even if it is possible to correct the horizontal position and orientation of the substrate 2 placed in the storage cassette 4 before placing the substrate 2 in the processing device 5, it is possible to shorten the transport time of the substrate 2 from the storage cassette 4 to the processing device 5.

In this embodiment, since the main body 10 cannot be moved forward or backward, the orientation of the hands 6 and 7 cannot be appropriately corrected when the robot 1 performs operations M14 and M24. However, in this embodiment, even if the orientation of the hands 6 and 7 cannot be appropriately corrected when the robot 1 performs operations M14 and M24, it is possible to appropriately correct the orientation of the hands 6 and 7 when the robot 1 performs operations M16 and M26.

(Example of a change in the robot control method)
In the embodiment described above, the control unit 32 may acquire position data D1 and D2 when the robot 1 performs operation M11, acquire position data D3 when the robot 1 performs operation M12, and correct the horizontal position and orientation of the hand 6 when it reaches hand position 6B based on the position data D1 to D3 when the robot 1 performs operation M13. In this case, after the robot 1 performs operation M11, when the robot 1 loads the substrate 2 placed in the storage cassette 3 onto the hand 6, the arm 8 is extended so that the hand 6 is positioned at the pre-taught hand position 6A. The substrate 2 is loaded onto the hand 6 in the same state (position and orientation) as it was placed in the storage cassette 3.

In this case, the control unit 32 determines the front-to-back and left-to-right positions and orientation of the substrate 2 mounted on the hand 6 based on the position data D1 to D3, compares the determined front-to-back and left-to-right positions (horizontal position) and orientation of the substrate 2 with the horizontal position and orientation of the substrate 2 previously taught to the robot 1, and corrects the horizontal position and orientation of the hand 6 when it reaches hand position 6B based on the comparison results when the robot 1 performs operation M13. Specifically, when the robot 1 performs operation M13, the control unit 32 controls the arm drive mechanism 27, rotation mechanism 29, and horizontal movement mechanism 31 based on the position data D1 to D3 to correct the horizontal position and orientation of the hand 6 when it reaches hand position 6B.

Similarly, in the embodiment described above, the control unit 32 may acquire position data D4 and D5 when the robot 1 performs operation M21, acquire position data D6 when the robot 1 performs operation M22, and correct the horizontal position and orientation of the hand 7 when it reaches hand position 7B based on position data D4 to D6 when the robot 1 performs operation M23. In this case, after the robot 1 performs operation M21, when the robot 1 places the substrate 2 placed in the storage cassette 3 on the hand 7, the arm 9 extends so that the hand 7 is positioned at the pre-taught hand position 7A. The hand 7 is loaded with the substrate 2 in the same state (position and orientation) as it was placed in the storage cassette 3.

In this case, the control unit 32 determines the front-rear and left-right positions and orientation of the substrate 2 placed on the hand 7 based on the position data D4 to D6, compares the determined front-rear and left-right positions (horizontal position) and orientation of the substrate 2 with the horizontal position and orientation of the substrate 2 previously taught to the robot 1, and corrects the horizontal position and orientation of the hand 7 when it reaches hand position 7B based on the comparison results when the robot 1 performs operation M23. Specifically, when the robot 1 performs operation M23, the control unit 32 controls the arm drive mechanism 28, rotation mechanism 29, and horizontal movement mechanism 31 based on the position data D4 to D6 to correct the horizontal position and orientation of the hand 7 when it reaches hand position 7B.

In this modified example, the storage cassette 3 is the receiving section, and hand positions 6A and 7A are receiving positions. Furthermore, operations M11 and M21 are first operations, operations M12 and M22 are second operations, and operations M13 and M23 are third operations. Furthermore, in this modified example, the front-to-back direction (X direction) is the first direction in which the hands 6 and 7 move when the robot 1 performs the first operations M11 and M21, and the left-to-right direction (X direction) is the second direction perpendicular to the up-down direction and the first direction. When the robot 1 performs operations M11, M12, M21, and M22, the two detection mechanisms 33 attached to the hand 6 and the two detection mechanisms 33 attached to the hand 7 are spaced apart in the left-to-right direction.

In this modified example, even if it is possible to correct the horizontal position and orientation of the substrate 2 placed in the storage cassette 3 before placing the substrate 2 in the processing device 5, it is possible to shorten the time it takes to transport the substrate 2 from the storage cassette 3 to the processing device 5.

(Other embodiments)
The above-described embodiment and modified examples are examples of preferred embodiments of the present invention, but the present invention is not limited to these and various modifications can be made within the scope of the present invention.

In the above-described embodiment, the robot 1 may transport the substrate 2 from the processing device 5 to the storage cassette 4. That is, the robot 1 may unload the substrate 2 from the processing device 5 and load the substrate 2 unloaded from the processing device 5 into the storage cassette 4. In this case, the processing device 5 serves as the receiving unit, and the storage cassette 4 serves as the delivery unit. Also, in a modified example of the robot control method described above, the robot 1 may transport the substrate 2 from the processing device 5 to the storage cassette 3. In this case, the processing device 5 serves as the receiving unit, and the storage cassette 3 serves as the delivery unit.

In the above-described embodiment, the robot 1 may be equipped with only one detection mechanism 34. In this case, the detection mechanism 34 is arranged so that when the robot 1 performs operation M12, the right end surface of the board 2 mounted on the hand 6 passes between the light-emitting unit 39 and the light-receiving unit 40 of one detection mechanism 34, and when the robot 1 performs operation M22, the right end surface of the board 2 mounted on the hand 7 passes between the light-emitting unit 39 and the light-receiving unit 40 of one detection mechanism 34. Furthermore, the detection mechanism 34 is arranged so that when the robot 1 performs operation M15, the rear end surface of the board 2 mounted on the hand 6 passes between the light-emitting unit 39 and the light-receiving unit 40 of one detection mechanism 34, and when the robot 1 performs operation M25, the right end surface of the board 2 mounted on the hand 7 passes between the light-emitting unit 39 and the light-receiving unit 40 of one detection mechanism 34.

In this case, when the robot 1 performs operations M12 and M15, the arm 9 is extended or retracted with the substrate 2 not being loaded on the hand 7, and when the robot 1 performs operations M22 and M25, the arm 8 is extended or retracted with the substrate 2 not being loaded on the hand 6.

In the above-described embodiment, the light receiving unit 40 may be an area sensor in which multiple light receiving elements are arranged two-dimensionally. Even in this case, the detection mechanism 34 can detect the left-right position of the right end surface of the substrate 2 placed on the hands 6 and 7, and the detection mechanism 34 can detect the front-to-back position of the rear end surface of the substrate 2 placed on the hands 6 and 7.

In the embodiment described above, arms 8 and 9 are arranged offset in the vertical direction, but arms 8 and 9 may be arranged at the same position in the vertical direction and adjacent to each other in the horizontal direction. Also, in the embodiment described above, robot 1 may be equipped with only one hand and one arm. For example, robot 1 may be equipped with only one hand 6 and one arm 8. Also, in the embodiment described above, arms 8 and 9 may be composed of three or more arm portions.

In the above-described embodiment, instead of arms 8 and 9, robot 1 may be provided with an arm, such as the arm of the industrial robot disclosed in JP 2018-15839 A, which is composed of two tip-side arm sections to which two hands 6 and 7 are rotatably connected at their tips, and a common arm section to which the base ends of the two tip-side arm sections are rotatably connected.

In addition, in the above-described embodiment, instead of arms 8 and 9, robot 1 may be provided with an elongated, approximately rectangular parallelepiped arm that holds hands 6 and 7 so that hands 6 and 7 can move linearly back and forth horizontally, like the arm of the industrial robot disclosed in JP 2019-25585 A. In other words, robot 1 may be a so-called linear type robot in which hands 6 and 7 are connected to an arm so that they can slide horizontally. In addition, in the above-described embodiment, the object to be transported by robot 1 may be something other than substrate 2.

1. Robots (industrial robots)
2. Substrate (glass substrate, transport object)
3, 4 Storage cassette (receiving section)
5. Processing equipment (delivery section)
6, 7 Hand 8, 9 Arm 10 Main body 21 First arm (arm)
22 Second arm portion (arm portion)
27, 28 Arm drive mechanism 29 Rotation mechanism 31 Horizontal movement mechanism 32 Control unit 33 Detection mechanism (first detection mechanism)
34 Detection mechanism (second detection mechanism)
37 Light-emitting unit (first light-emitting unit)
38 Light receiving unit (first light receiving unit)
39 Light-emitting unit (second light-emitting unit)
40 Light receiving unit (second light receiving unit)
X Front-back direction Y Left-right direction

Claims (6)

An industrial robot that transports a rectangular or square-shaped object,
The industrial robot includes a hand on which the transport object is placed and which is movable in a horizontal direction, an arm to which the hand is connected, a main body to which the arm is connected so as to be rotatable with the vertical direction as the axis of rotation, two optical first detection mechanisms attached to the hand, a second optical detection mechanism attached to the main body, and a control unit that controls the industrial robot,
The position of the hand when the tip of the hand moves in a direction away from the main body and the hand loads and receives the transport object placed on a predetermined receiving section is defined as a receiving position, and the position of the hand when the tip of the hand moves in a direction away from the main body and the hand delivers the transport object loaded on the hand to a predetermined delivery section is defined as a delivery position.
a first action which is an action of the hand moving to the receiving position so that the tip of the hand moves away from the main body; a second action which is an action of the hand receiving the transport object at the receiving position after the first action, moving so that the tip of the hand approaches the main body; and a third action which is an action of the hand with the transport object loaded thereon moving to the delivery position so that the tip of the hand moves away from the main body after the second action,
the hand moves linearly while facing a fixed direction relative to the main body when the industrial robot performs the first operation and the second operation;
When the direction of movement of the hand when the industrial robot performs the first operation and the second operation is defined as a first direction, and when the direction orthogonal to the first direction and the up-down direction is defined as a second direction,
the first detection mechanism is a reflective detection mechanism including a first light-emitting unit and a first light-receiving unit that receives light emitted from the first light-emitting unit and reflected by the transport object,
the two first detection mechanisms are arranged at an interval in the second direction;
the second detection mechanism is a transmission-type detection mechanism having a second light-receiving unit formed of a line sensor or an area sensor, and a second light-emitting unit disposed opposite the second light-receiving unit with a predetermined gap between the second light-receiving unit and the second light-emitting unit in the vertical direction,
when the industrial robot performs the first operation, the two first detection mechanisms pass under the object placed on the receiving section,
when the industrial robot performs the second operation, one end surface of the object to be transported mounted on the hand in the second direction passes between the second light receiving unit and the second light emitting unit,
the control unit acquires, when the industrial robot performs the first operation, first position data which is data on the position of the hand in the first direction when one of the two first detection mechanisms detects the transported object, and second position data which is data on the position of the hand in the first direction when the other of the two first detection mechanisms detects the transported object; and, when the industrial robot performs the second operation, acquires third position data which is data on the position in the second direction of one end face of the transported object in the second direction detected by the second detection mechanism when the hand moves to a predetermined measurement position; and, when the industrial robot performs the third operation, corrects the horizontal position and orientation of the hand when it reaches the delivery position based on the first position data, the second position data, and the third position data. The arm is composed of a plurality of arm portions that are rotatably connected to each other and is extendable and contractible in the horizontal direction.
the hand is rotatably connected to the tip end of the arm,
2. The industrial robot according to claim 1, wherein a base end of the arm is rotatably connected to the main body. an arm drive mechanism that extends and retracts the arm so that the hand moves linearly with respect to the main body while facing in a fixed direction; a rotation mechanism that rotates the main body; and a horizontal movement mechanism that moves the main body in a left-right direction perpendicular to the up-down direction,
the hand moves linearly relative to the main body in a front-rear direction perpendicular to the up-down direction and the left-right direction when the industrial robot performs the third operation,
3. The industrial robot according to claim 2, wherein, when the industrial robot performs the third operation, the control unit controls the arm drive mechanism, the rotation mechanism, and the horizontal movement mechanism based on the first position data, the second position data, and the third position data to correct the horizontal position and orientation of the hand when the industrial robot reaches the transfer position. the first direction coincides with the left-right direction,
4. The industrial robot according to claim 3, wherein the hand moves linearly in the left-right direction relative to the main body when the industrial robot performs the first operation and the second operation. The first direction coincides with a front-rear direction,
4. The industrial robot according to claim 3, wherein the hand moves linearly in a front-to-rear direction relative to the main body when the industrial robot performs the first operation and the second operation. The transport device includes a hand on which a rectangular or square object to be transported is placed and which is movable in a horizontal direction, an arm to which the hand is connected, a main body to which the arm is connected so as to be rotatable with the vertical direction as the axis of rotation, two first optical detection mechanisms attached to the hand, and a second optical detection mechanism attached to the main body,
The position of the hand when the tip of the hand moves in a direction away from the main body and the hand loads and receives the transport object placed on a predetermined receiving section is defined as a receiving position, and the position of the hand when the tip of the hand moves in a direction away from the main body and the hand delivers the transport object loaded on the hand to a predetermined delivery section is defined as a delivery position.
a first action which is an action of the hand moving to the receiving position so that the tip of the hand moves away from the main body; a second action which is an action of the hand receiving the transport object at the receiving position after the first action, moving so that the tip of the hand approaches the main body; and a third action which is an action of the hand with the transport object loaded thereon moving to the delivery position so that the tip of the hand moves away from the main body after the second action,
the hand moves linearly while facing a fixed direction relative to the main body when the first operation and the second operation are performed;
When the moving direction of the hand when the first operation and the second operation are performed is defined as a first direction, and a direction perpendicular to the first direction and the up-down direction is defined as a second direction,
the first detection mechanism is a reflective detection mechanism including a first light-emitting unit and a first light-receiving unit that receives light emitted from the first light-emitting unit and reflected by the transport object,
the two first detection mechanisms are arranged at an interval in the second direction;
the second detection mechanism is a transmission-type detection mechanism having a second light-receiving unit formed of a line sensor or an area sensor, and a second light-emitting unit disposed opposite the second light-receiving unit with a predetermined gap between the second light-receiving unit and the second light-emitting unit in the vertical direction,
When the first operation is performed, the two first detection mechanisms pass under the object placed in the receiving section,
a control method for an industrial robot, wherein, when the second operation is performed, one end face in the second direction of the object to be transported, which is mounted on the hand, passes between the second light receiving unit and the second light emitting unit,
a control method for an industrial robot, characterized in that, when performing the first operation, first position data is acquired which is data on the position of the hand in the first direction when one of the two first detection mechanisms detects the transported object, and second position data is data on the position of the hand in the first direction when the other of the two first detection mechanisms detects the transported object; when performing the second operation, third position data is acquired which is data on the position in the second direction of one end face of the transported object in the second direction detected by the second detection mechanism when the hand moves to a predetermined measurement position; and when performing the third operation, correcting the horizontal position and orientation of the hand when it reaches the delivery position based on the first position data, the second position data, and the third position data.