Robot system

Abstract

This robot system (100) comprises: an operation device (20) that detects an operation action performed by an operator; a robot (10) that acts in conjunction with the operation action detected by the operation device (20); and a control unit (29) that switches the action range of the robot (10) from a normal range to a limited range that is a smaller range than the normal range.

Description

Robot System

[0001] This disclosure relates to robotic systems.

[0002] Conventionally, systems that cause a slave device to follow a master device are known. For example, Japanese Patent No. 6,964,293 discloses a haptic force transmission system that includes a master device including a manipulator and a slave device including a contactor that contacts a contact object. In the system disclosed in Japanese Patent No. 6,964,293, a force applied by an operator to an operation unit of the master device is transmitted to the slave device through bilateral control in which the operations of the master device and the slave device follow each other. As a result, the slave device operates in conjunction with the force applied to the manipulator by the operator.

[0003] Patent No. 6964293

[0004] However, in the haptic force transmission system of Japanese Patent No. 6964293, the slave device is operated in conjunction with the operator's operation on the master device, so the operator's operation on the master device is directly reflected in the operation of the slave device. Therefore, the operator must be careful not to make excessively large operation movements on the operation device serving as the master device, so as to avoid excessively large movements of the robot serving as the slave device. This reduces the ease of operation when operating the robot, as the operator must pay attention to the operating range. Therefore, it is desirable to suppress the decrease in ease of operation when operating a robot in conjunction with the operator's operation.

[0005] This disclosure has been made to solve the above-mentioned problems, and one purpose of this disclosure is to provide a robot system that can suppress a decrease in workability when the robot is operated in conjunction with the operating actions of an operator.

[0006] A robot system according to one aspect of the present disclosure includes an operating device that detects an operating action by an operator, a robot that operates in conjunction with the operating action detected by the operating device, and a control unit that switches the operating range of the robot from a normal range to a limited range that is smaller than the normal range.

[0007] As described above, a robot system according to one aspect of the present disclosure includes a control unit that switches the robot's operating range from a normal range to a limited range that is smaller than the normal range. By switching the robot's operating range to a limited range that is smaller than the normal range, the control unit can automatically prevent the robot's operating range from becoming too large. Therefore, the robot's operating range can be prevented from becoming too large without the operator having to pay attention to the operating range when performing an operation. As a result, a decrease in workability can be prevented when the robot is operated in conjunction with an operator's operation.

[0008] According to the present disclosure, when a robot is operated in conjunction with an operating action by an operator, a decrease in workability can be suppressed.

[0009] FIG. 1 is a perspective view showing the overall configuration of a robot system according to an embodiment; FIG. 2 is a block diagram showing the configuration of a robot system according to an embodiment; FIG. 3 is a perspective view for explaining the configuration of an operation device according to an embodiment; FIG. 4 is a diagram schematically showing the operating range of a robot in a normal range; FIG. 5 is a diagram schematically showing the operating range of a robot in a limited range; FIG. 6 is a diagram schematically showing a touch panel of a teaching device; FIG. 7 is a diagram for explaining switching between a base coordinate system and a tool coordinate system; and FIG. 8 is a flowchart for explaining processing for switching the operating range of a robot by a robot system.

[0010] Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings.

[0011] The configuration of a robot system 100 according to this embodiment will be described with reference to FIGS. 1 to 7.

[0012] (Configuration of Robot System) As shown in FIG. 1, the robot system 100 includes a robot 10 and an operating device 20. The robot system 100 is a master-slave system. The robot 10 is a slave device that operates in conjunction with an operating action of an operator detected by the operating device 20 via remote control. The robot 10 is connected to the operating device 20 via a network. The operating device 20 is a master device that detects the operating action of the operator. In this embodiment, the robot 10 is an industrial robot that performs grinding processing such as deburring on a workpiece 101, for example.

[0013] 2 , specifically, the robot 10 includes a control unit 19. The control unit 19 controls the operation of each unit of the robot 10. The operation device 20 includes a control unit 29. The control unit 29 controls the operation of each unit of the operation device 20. The robot system 100 operates as a remotely controlled master-slave system by the control unit 19 of the robot 10 and the control unit 29 of the operation device 20 transmitting and receiving signals to and from each other.

[0014] The robot 10 includes a robot arm 11, a processing tool 12, and a sensor 13. The robot arm 11 is a six-axis vertical articulated robot arm having multiple link members. The base end of the robot arm 11 is attached to a base fixed to the floor. A processing tool 12, which serves as an end effector, is attached to the tip of the robot arm 11. The processing tool 12 includes a grinder that performs grinding on a workpiece 101 by rotating a disk member. The sensor 13 is disposed between the processing tool 12 and the robot arm 11 at the tip of the robot arm 11. That is, the processing tool 12 is attached to the robot arm 11 via the sensor 13. The sensor 13 includes, for example, a piezoelectric, optical, capacitive, or strain gauge force sensor. The sensor 13 detects a contact force applied to the robot 10. For example, the sensor 13 detects six-axial forces, including forces along three mutually orthogonal axial directions and rotational forces about three mutually orthogonal axial directions. The sensor 13 detects a contact force generated when the machining tool 12 comes into contact with the workpiece 101 due to the operation of the robot arm 11. The sensor 13 is an example of a contact sensor.

[0015] The control unit 19 includes a calculation device such as a central processing unit (CPU), memories such as a random access memory (RAM) and a read-only memory (ROM), and a storage device such as a hard disk. The control unit 19 executes control processing using the calculation device based on programs and parameters stored in the storage device. The control unit 19 also includes a communication module. The control unit 19 controls the operation of each part of the robot 10 based on control signals acquired from a control unit 29 of the operation device 20 via the communication module. The control unit 19 outputs the detection results of the contact force detected by the sensor 13 to the control unit 29. The control unit 19 also controls the operation of a drive source including a servo motor to rotate the joints of the robot arm 11 and operate the robot arm 11. The control unit 19 operates the robot arm 11 to change the position and inclination of the processing tool 12. The control unit 19 also controls the operation of the processing tool 12. For example, the control unit 19 has a main CPU that controls the overall operation of the robot 10 and a servo CPU that controls the current supplied to a drive source including a servo motor.

[0016] As shown in FIG. 3 , the operating device 20 includes a gripper 21, a link member 22, a drive unit 23, and a sensor 24. The drive unit 23 is an example of an operation drive unit. The gripper 21 is held by an operator to control the operation of the robot 10. The gripper 21 is held, for example, with both hands of the operator, and its position and inclination are changed by the operator's operation. The gripper 21 also includes a switch 21a. The switch 21a accepts an input operation to control the operation of the processing tool 12. For example, the switch 21a accepts an input operation to switch on and off the rotation of a grinder disk member of the processing tool 12. The link member 22 has six arm members with a parallel link structure that support a support plate 21b on which the gripper 21 is disposed.

[0017] In the link member 22, a pair of arm members are arranged radially from the support plate 21b in three different directions. In each of the six arm members of the link member 22, two rod-shaped members are connected to each other via a joint. The joint connecting the rod-shaped members is a universal joint such as a ball joint, and rotates around three axes. Each of the six arm members of the link member 22 is connected to the support plate 21b, on whose tip the gripper 21 is disposed, via a joint portion that is a universal joint such as a ball joint. The drive unit 23 includes a servo motor arranged for each of the six arm members of the link member 22. The drive unit 23 drives each of the six arm members of the link member 22. Each of the six arm members of the link member 22 is connected at its base end opposite the gripper 21 to the rotation shaft of the servo motor of the drive unit 23 via a reducer or the like. The drive unit 23 drives the link member 22, thereby driving the gripper 21 connected to the link member 22. The drive unit 23 also includes an encoder as a detection unit that detects the rotational position around the axis of the servo motor. In this embodiment, the drive unit 23 links the operation device 20 with the robot 10. The linked operation between the operation device 20 and the robot 10 will be described in detail below.

[0018] Like the sensor 13 of the robot 10, the sensor 24 includes a force sensor such as a piezoelectric, optical, or capacitance sensor, or a strain gauge. The sensor 24 detects the operating force applied to the gripper 21 by the operator's operating action. The sensor 24 is disposed between the gripper 21 and the link member 22. Specifically, the sensor 24 is disposed on the support plate 21b. For example, the sensor 24 detects six-axial forces, including forces along three mutually orthogonal axial directions and rotational forces about the three mutually orthogonal axial directions.

[0019] As shown in FIG. 1 , the operation device 20 includes a teaching device 25 and a storage unit 26. The teaching device 25 accepts input operations from an operator. The teaching device 25 has a touch panel 25a and a plurality of operation switches 25b. The teaching device 25 accepts operations for teaching the robot 10 to operate based on input operations on the touch panel 25a and the plurality of operation switches 25b. That is, the teaching device 25 accepts input operations for storing setting values ​​for controlling the operation of the robot 10. The teaching device 25 is a so-called teaching pendant. The teaching device 25 is connected to a control unit 29. The teaching device 25 outputs an operation signal based on the accepted input operation to the control unit 29. Furthermore, the teaching device 25 displays information indicating the state of the robot system 10 on the touch panel 25a based on a signal from the control unit 29. The teaching device 25 is an example of a switching operation unit.

[0020] The memory unit 26 stores programs executed by the control unit 29 and parameters for the control of the operation device 20 by the control unit 29. The memory unit 26 includes a storage device such as a hard disk. The control unit 29 includes a calculation device such as a CPU and a memory. Like the control unit 19, the control unit 29 executes control processing by the calculation device based on the programs and parameters stored in the memory unit 26. The control unit 29 also includes a communication module. The control unit 29 generates control signals for operating the robot 10 and outputs the generated control signals to the control unit 19 of the robot 10 via the communication module. The control unit 29 operates the drive unit 23. The control unit 29 also acquires operation signals from the teaching device 25.

[0021] <Interlocking Between Manipulation Device and Robot> The robot system 100 performs bilateral control in which the attitude and force of the robot 10 and the manipulation device 20 are synchronized with each other. The control unit 29 of the manipulation device 20 acquires the detection results of the detector of the drive unit 23 and the detection results of the sensor 24. Then, based on the acquired detection results, the control unit 29 of the manipulation device 20 detects an operation action by the operator to move the gripper 21. The control unit 29 detects the attitude including the position and angle of the gripper 21 and the operation action including the force applied to the gripper 21. Then, based on the detected operation action, the control unit 29 generates an operation signal for operating the robot 10. The control unit 29 operates the robot 10 in conjunction with the operation action to move the gripper 21, thereby changing the position and angle of the machining tool 12 of the robot 10. That is, based on the operation signal from the control unit 29, the robot 10 changes the position and angle of the processing tool 12 so as to follow the attitude, including the position and angle, of the gripper 21 changed by the operator's operating action, and controls the force that the processing tool 12 applies to the workpiece 101 so as to follow the operating force applied to the gripper 21. For example, the robot 10 operates to move the processing tool 12 a distance and in a direction equivalent to the distance and direction, respectively, moved by the gripper 21 of the operating device 20.

[0022] Furthermore, in this embodiment, the control unit 29 operates the drive unit 23 in conjunction with the detected contact force based on the detection result of the contact force detected by the sensor 13 of the robot 10. Specifically, the control unit 29 controls the operation of the drive unit 23, thereby controlling the output of the drive unit 23 so as to follow the contact force detected by the sensor 13. As a result, the contact force caused by the contact of the processing tool 12 with the workpiece 101 is transmitted to the operator who grips the gripper 21. In other words, the control unit 29 controls the output of the drive unit 23, which operates the gripper 21, so that the contact force caused by the contact of the processing tool 12 with the workpiece 101 is fed back to the operator.

[0023] (Switching of Operational Range) As shown in FIG. 4 , a normal range is preset as the operational range of the robot 10. The operational range of the robot 10 is set based on a control point set for the robot 10. For example, the control unit 29 sets the position of the tip of the processing tool 12 of the robot 10 as the reference control point. The control unit 29 detects an operation performed on the gripper 21 and changes the position and inclination of the control point, which is the tip of the processing tool 12, in conjunction with the operation. The normal range as the operational range of the robot 10 is set based on a preset reference position and a range of three-dimensional directions based on the reference position. For example, in a base coordinate system, which is a spatial coordinate system based on an absolute three-dimensional space in which the robot 10 is located, coordinates of a reference position in the normal range are set in advance. Then, the position and size of the normal range are set by setting each range in the three-dimensional directions in the base coordinate system. The setting of the normal range is stored in advance in the storage unit 26. The control unit 29 controls the operation of the robot 10 so that the position of the control point is included in the normal range. Furthermore, the movement range of the gripper 21 is limited so as to follow the movement range of the robot 10. For example, if the operator attempts to move the gripper 21 so as to operate the robot 10 beyond the normal range, the control unit 29 controls the driving of the drive unit 23, thereby generating a driving force in the gripper 21 that repels the operating force.

[0024] 5, in the robot system 100, the motion range of the robot 10 is limited by an input operation by an operator. In this embodiment, the teaching device 25 accepts an operation to switch the motion range of the robot 10. Then, the control unit 29 switches the motion range of the robot 10 from the normal range to the limited range based on the operation accepted by the teaching device 25. In the limited range, the motion range of the robot 10 is smaller than the normal range. The size of the limited range is set in advance and stored in the storage unit 26.

[0025] The limited range as the operating range of the robot 10 is set based on a preset reference position and a three-dimensional range based on the reference position, similar to the normal range. In this embodiment, the control unit 29 sets the reference position of the control point of the robot 10 within the limited range and limits the operating range of the control point from the set reference position, thereby setting the limited range. Specifically, the control unit 29 sets the position of the control point at the timing when a contact force due to contact of the machining tool 12 with the workpiece 101 is detected as the reference position, based on the detection result from the sensor 13.

[0026] For example, the control unit 29 sets the operating range of the robot 10 to the normal range when the reference position of the limited range has not been set. With the operation of the machining tool 12 stopped, the operator performs an operation on the gripper 21 so that the tip of the machining tool 12 comes into contact with the workpiece 101. The control unit 29 operates the robot 10 in conjunction with the operation, and when the sensor 13 detects a contact force caused by the machining tool 12 contacting the workpiece 101, sets the position of the control point at the time the contact force is detected as the reference position. When the operating range of the robot 10 is switched to the limited range, the control unit 29 controls the operation of the robot 10 so that the position of the control point is included in the limited range, as in the operation in the normal range. In this way, the control unit 29 switches the operating range of the robot 10, thereby switching the movement range of the machining tool 12. The control unit 29 also limits the movement range of the gripper 21 of the operating device 20 in accordance with the operating range of the robot 10, corresponding to each of the normal range and the limited range. That is, when the motion range of the robot 10 is switched from the normal range to the limited range, the control unit 29 limits the movement range of the gripper 21 to correspond to the switched motion range.

[0027] As shown in FIG. 6 , the control unit 29 displays a switch button 31 for switching remote control on and off on the touch panel 25a of the teaching device 25. For example, the control unit 29 switches between a state in which the robot 10 operates in conjunction with an operating action on the gripper 21 and a state in which the robot 10 is stopped without being operated, based on an input operation on the teaching device 25. The control unit 29 switches remote control on and off when an input operation on the switch button 31 by the operator is received. In this embodiment, the control unit 29 switches the operating range of the robot 10 when the robot 10 is no longer operating in conjunction with an operating action detected by the operating device 20. When the remote control is off, the robot 10 waits in a stopped state even when an operating action is performed on the operating device 20. The control unit 29 accepts an operation to switch the operating range between the normal range and the limited range only when the remote control is off. In other words, the control unit 29 does not accept an operation to switch the operating range when the remote control is on. The control unit 29 also displays a movement restriction button 32, which switches the movement range of the robot 10 between a normal range and a limited range, on the touch panel 25a of the teaching device 25. When the control unit 29 receives an input operation on the movement restriction button 32 while the remote control is off, it switches the movement restriction between on and off. When the movement restriction is on, the movement range of the robot 10 becomes the limited range, and when the movement restriction is off, the movement range of the robot 10 becomes the normal range.

[0028] <Changing the Size of the Limited Range> The teaching device 25 displays the size of a preset normal range and the size of a limited range on the touch panel 25a. For example, in a base coordinate system in which the robot 10 is placed, the vertical direction is the Z direction, and two mutually perpendicular directions in a horizontal plane perpendicular to the vertical direction are the X direction and the Y direction. The sizes of the ranges in the X direction, Y direction, and Z direction are set, thereby setting the sizes of the normal range and the limited range. The touch panel 25a displays numerical values ​​representing the sizes of the normal range and the limited range in the X direction, Y direction, and Z direction. For example, FIG. 6 shows an example in which the range in the Z direction is limited to −800 mm in the normal range and −20 mm in the limited range.

[0029] In the present embodiment, the teaching device 25 accepts an operation to change the size of the limited range. The control unit 29 changes the size of the limited range stored in the storage unit 26 based on the operation accepted by the teaching device 25. The control unit 29 stores the changed size of the limited range in the storage unit 26. For example, the control unit 29 changes the numerical values ​​that define the size of the limited range in each of the X direction, Y direction, and Z direction based on operations on the touch panel 25 a and the multiple operation switches 25 b of the teaching device 25 while linkage with the operating motion of the robot 10 is stopped.

[0030] (Coordinate System Switching) As shown in FIG. 7 , in this embodiment, the control unit 29 switches between operating the robot 10 in a tool coordinate system based on the machining tool 12 and operating the robot 10 in a base coordinate system based on an absolute three-dimensional space regardless of the orientation of the machining tool 12. In the tool coordinate system, the robot 10 operates in a spatial coordinate system based on the orientation of the machining tool 12. Therefore, when the machining tool 12 is operated so as to be tilted, the vertical direction relative to the machining tool 12 based on the tilted machining tool 12 becomes the Z direction in the operating range of the robot 10. In other words, in the tool coordinate system, when the machining tool 12 is tilted, the orientation serving as the reference for the operating range is changed in accordance with the tilt of the machining tool 12. Note that even in the case of the tool coordinate system, the operating device 20 operates in a spatial coordinate system based on an absolute three-dimensional space. For example, as shown in the right diagram of Figure 7, in the tool coordinate system, the operation of the robot 10 is based on a spatial coordinate system that is based on the perpendicular direction relative to the machining tool 12, while the operation of the operating device 20 is based on a spatial coordinate system that is based on the vertical direction. Therefore, in the operation in the tool coordinate system, when the machining tool 12 is tilted, the direction in which the gripper 21 is moved differs from the direction in which the machining tool 12 actually moves. On the other hand, in the base coordinate system, both the operation of the robot 10 and the operation of the operating device 20 are based on a spatial coordinate system that is based on the vertical direction, for example. Therefore, in the base coordinate system, even if the robot 10 performs an operation that tilts the machining tool 12, both the normal range and the limited range of operation of the robot 10 are not changed.

[0031] The control unit 29 switches between the tool coordinate system and the base coordinate system based on an input operation by the operator. For example, by disposing an imaging unit that captures an image of the robot 10 and a display unit that displays an image captured by the imaging unit in the robot system 100, the tool coordinate system and the base coordinate system can be switched when the operator performs an operation on the operation device 20 by remote control while visually checking the image on the display unit. When the operator remotely controls the robot 10 while visually checking the image from the imaging unit disposed on the robot 10 main body, such as the robot arm 11, an operation in the tool coordinate system is selected. On the other hand, when the operator remotely controls the robot 10 while visually checking the image from the imaging unit disposed in a position different from the robot 10, an operation in the base coordinate system is selected. An operation in the base coordinate system is also selected when the robot 10 is directly visually checked.

[0032] In this embodiment, the control unit 29 switches the operating range of the robot 10 from the normal range to the limited range for each of the operation of the robot 10 in the tool coordinate system and the operation of the robot 10 in the base coordinate system. That is, regardless of whether the tool coordinate system or the base coordinate system is selected, the control unit 29 switches the operating range based on the selected coordinate system between the normal range and the limited range. Therefore, in the tool coordinate system, the orientation of the operating range in absolute space changes every time the machining tool 12 is tilted, and therefore the range of the limited range in absolute space also changes.

[0033] (Robot Operation Range Switching Process) The operation range switching process of the robot 10 performed by the robot system 100 in this embodiment will be described based on a flowchart with reference to Fig. 8. The control processes from step S1 to step S6 are executed by the control unit 29.

[0034] First, in step S1, an operation by an operator is detected with the motion range of the robot 10 set to the normal range, thereby remotely controlling the operation of the robot 10. Specifically, an operation applied to the gripper 21 is detected, and an operation signal for operating the robot 10 in conjunction with the detected operation is generated, and the generated operation signal is output to the robot 10.

[0035] Next, in step S2, a reference position within the limited range is set, thereby setting the limited range. Specifically, when the machining tool 12 comes into contact with the workpiece 101, the sensor 13 of the robot 10 detects a contact force. The sensor 13 then acquires the detection result of the contact force, and based on the acquired detection result, the position of the control point, which is the tip of the machining tool 12, at the time the contact force was detected is set as the reference position of the limited range. Using the set reference position as a reference, the spatial position and size of the limited range are set based on the size of the limited range that has been set in advance.

[0036] Next, in step S3, it is determined whether or not the linkage of the robot 10 with the operation action by the operator has been stopped. That is, it is determined whether or not the switch button 31 displayed on the touch panel 25a of the teaching device 25 has been operated to switch the remote control from an ON state to an OFF state. If it is determined that the linkage of the robot 10 with the operation action by the operator has been stopped, the process proceeds to step S4. If it is not determined that the linkage of the robot 10 with the operation action by the operator has been stopped, the control process is put on hold.

[0037] In step S4, it is determined whether the motion range of the robot 10 has been switched from the normal range to the limited range. That is, it is determined whether the motion limit button 32 displayed on the touch panel 25a of the teaching device 25 has been operated to enable a motion limit that switches the motion range of the robot 10 from the normal range to a smaller limited range. If it is determined that the motion range of the robot 10 has been switched from the normal range to the limited range, the process proceeds to step S5. If it is not determined that the motion range of the robot 10 has been switched from the normal range to the limited range, the process proceeds to step S6.

[0038] In step S5, an operating action by the operator is detected with the motion range of the robot 10 set to the limited range, thereby remotely controlling the motion of the robot 10. Specifically, with the motion range of the robot 10 switched to the limited range in step S4, the switch button 31 displayed on the touch panel 25a of the teaching device 25 is operated, whereby the remote control is switched from the OFF state to the ON state, and the motion of the robot 10 is remotely controlled.

[0039] In step S6, similarly to step S1, an operating action by the operator is detected with the motion range of the robot 10 set to the normal range, thereby remotely controlling the motion of the robot 10. Specifically, in step S4, with the motion range of the robot 10 not switched but still set to the normal range, the switch button 31 displayed on the touch panel 25a of the teaching device 25 is operated, whereby the remote control is switched from the OFF state to the ON state, and the motion of the robot 10 is remotely controlled.

[0040] Note that a step of accepting an operation to set the size of the limited range may be executed. The step of setting the size of the limited range may be executed at any timing between steps S1 and S6, but may be executed, for example, after step S3, with the interlocking of the robot 10 stopped. Also, a step of switching between the base coordinate system and the tool coordinate system in which the robot 10 is to operate may be executed. The step of switching the coordinate system may be executed at any timing between steps S1 and S6, but may be executed, for example, after step S3, with the interlocking of the robot 10 stopped.

[0041] [Effects of this embodiment] In this embodiment, the following effects can be obtained.

[0042] The robot system 100 includes a control unit 29 that switches the motion range of the robot 10 from a normal range to a limited range that is smaller than the normal range. By switching the motion range of the robot 10 to a limited range that is smaller than the normal range, the control unit 29 can automatically prevent the motion range of the robot 10 from becoming too large. Therefore, even if the operator does not pay attention to the motion range when performing an operation, the motion range of the robot 10 can be prevented from becoming too large. As a result, when the robot 10 is operated in conjunction with an operation by an operator, a decrease in workability can be prevented.

[0043] The robot system 100 includes a teaching device 25 as a switching operation unit that receives an operation to switch the operating range of the robot 10. The control unit 29 switches the operating range of the robot 10 from the normal range to the limited range based on the operation received by the teaching device 25. This allows the operating range of the robot 10 to be switched from the normal range to the limited range by an operation by the operator, so that the operating range of the robot 10 can be switched at a timing intended by the operator. This prevents the operating range of the robot 10 from being restricted to a small size at a timing unintended by the operator. As a result, a decrease in workability when operating the robot 10 can be further prevented.

[0044] The control unit 29 sets a reference position of the control point set for the robot 10, and sets the limited range by limiting the movement range of the control point from the set reference position. This allows the operator to easily understand the small, limited movement range of the robot 10 by understanding the set reference position. Therefore, the operator can easily operate the robot 10 with the movement range of the robot 10 switched to the limited range, thereby further suppressing a decrease in workability when operating the robot 10.

[0045] The robot 10 includes a sensor 13 as a contact sensor that detects a contact force applied to the robot 10. The control unit 29 sets the position of the control point at the time when the contact force is detected as a reference position based on the detection result from the sensor 13. This allows the position at which the contact force is applied to the robot 10 to be automatically set as the reference position, making it possible to narrowly limit the operating range of the robot 10 based on the state in which the robot 10 is in contact with the workpiece 101, which is the target object. Therefore, when the robot 10 performs handling tasks such as processing, transporting, and assembling the workpiece 101, it is possible to effectively prevent a decrease in workability in operating the robot 10.

[0046] The operation device 20 includes a gripper 21 that is held by an operator, and detects an operation action performed by the operator to move the gripper 21. The robot 10 operates in conjunction with the operation action performed by the operator to move the gripper 21. The control unit 29 limits the movement range of the gripper 21 in accordance with each of the normal and limited movement ranges of the robot 10. This allows the operator operating the robot 10 while holding the gripper 21 to intuitively and easily recognize the movement range of the robot 10 due to the restriction on the movement range of the gripper 21. As a result, the operator can intuitively and easily operate the robot 10, thereby further suppressing a decrease in workability when operating the robot 10.

[0047] The control unit 29 switches the motion range of the robot 10 while the robot 10 is stopped from linking with the operation motion detected by the operation device 20. This allows the motion range of the robot 10 to be switched while the robot 10 is stopped. Therefore, unlike when the motion range of the robot 10 is switched while the robot 10 is operating, it is possible to prevent the motion of the robot 10 from becoming unstable.

[0048] The robot system 100 includes a storage unit 26 that stores the size of a preset limit range. The teaching device 25, which serves as a switching operation unit, accepts an operation to change the size of the limit range. The control unit 29 changes the size of the limit range stored in the storage unit 26 based on the operation accepted by the teaching device 25. This allows the operator to change the size of the limit range that narrows the operating range of the robot 10, thereby enabling the operator to easily set an appropriate operating range for the robot 10.

[0049] The teaching device 25, which serves as a switching operation unit, accepts an operation for teaching the robot 10 to operate. The control unit 29 switches the operating range of the robot 10 based on the operation for switching the operating range accepted by the teaching device 25, which accepts the operation for teaching. This makes it possible to prevent the configuration of the robot system 100 from becoming complicated, compared to when an operation unit for accepting an operation for teaching and an operation unit for switching the operating range of the robot 10 are separately arranged.

[0050] The robot 10 includes a robot arm 11 to which a processing tool 12 for performing grinding is attached. The control unit 29 switches the operating range of the robot 10, thereby switching the movement range of the processing tool 12. This effectively prevents the robot 10 from moving too large when the robot 10 performs grinding work using the processing tool 12. As a result, during grinding work, it is possible to prevent a decrease in workability in operating the robot 10 and effectively prevent the workpiece 101 from being over-ground.

[0051] The robot 10 includes a robot arm 11 to which a processing tool 12 is attached. The control unit 29 switches between operating the robot 10 in a tool coordinate system based on the orientation of the processing tool 12 and operating the robot 10 in a base coordinate system based on an absolute three-dimensional space regardless of the orientation of the processing tool 12. The control unit 29 also switches the operating range of the robot 10 from a normal range to a limited range for each of the operation of the robot 10 in the tool coordinate system and the operation of the robot 10 in the base coordinate system. This makes it possible to suppress a decrease in workability in operating the robot 10 both when operating the robot 10 in a subjective tool coordinate system based on the orientation of the tool and when operating the robot 10 in an absolute base coordinate system based on three-dimensional space. Therefore, when an operator selects a coordinate system that is easy to operate the robot 10, a decrease in workability in operating the robot 10 can be effectively suppressed regardless of whether the operator selects the tool coordinate system or the base coordinate system.

[0052] The robot 10 includes a sensor 13 as a contact sensor that detects a contact force applied to the robot 10. The operation device 20 includes a drive unit 23 as an operation drive unit that links the operation device 20 with the robot 10. The control unit 29 operates the drive unit 23 in conjunction with the contact force based on the detection result detected by the sensor 13. This allows the operator to recognize the contact force detected by the sensor 13 based on the drive force from the drive unit 23. Therefore, the operator can easily recognize whether the robot 10 has come into contact with the target object, the workpiece 101, and can perform an operation to operate the robot 10 while switching the operating range based on the position of contact with the workpiece 101. As a result, when performing work on the workpiece 101, deterioration in workability in operating the robot 10 can be further suppressed.

[0053] The robot 10 is remotely controlled to operate in conjunction with an operation motion detected by the operation device 20. The control unit 29 switches the operation range of the robot 10, which is remotely controlled to operate in conjunction with an operation motion detected by the operation device 20, from a normal range to a limited range. This effectively prevents a decrease in workability in operating the robot 10 when the robot 10 is operated by remote control.

[0054] [Modifications] The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present disclosure is defined by the claims, not by the description of the above-mentioned embodiments, and includes all modifications (modifications) within the meaning and scope of the claims.

[0055] For example, in the above embodiment, an example was described in which the operating range of the robot 10 was switched from the normal range to the limited range based on an operation received by the teaching device 25 as a switching operation unit, but the present disclosure is not limited to this. In the present disclosure, the operating range may be automatically switched from the normal range to the limited range by the control unit. For example, the operating range of the robot may be automatically switched from the normal range to the limited range when a contact sensor such as a force sensor detects contact between the robot's processing tool and the target workpiece.

[0056] In the above embodiment, an example was described in which the limited range was set by limiting the operating range of a control point, which is the tip of the processing tool 12, from a reference position. However, the present disclosure is not limited to this. In the present disclosure, multiple control points may be set for a robot including a robot arm and a processing tool, and a normal range and a limited range, which are the operating ranges of the robot, may be set based on the multiple control points. That is, when setting a limited range, the operating range of the robot may be limited so that multiple control points are located within the limited range. Furthermore, when setting a limited range by limiting the operating range of one control point based on a reference position, the control point may be set for the robot arm rather than the processing tool. Furthermore, a point in space separated from the processing tool and the robot arm themselves may be set as the control point.

[0057] In the above embodiment, the position of the control point at the timing when a contact force is detected based on the detection result from the sensor 13 serving as a contact sensor is set as the reference position. However, the present disclosure is not limited to this. In the present disclosure, the reference position may be set based on an operation by an operator. For example, the position of the control point at the timing when the robot's operating range is switched from the normal range to the limited range by an operation by the operator may be set as the reference position. For example, when the detection result from a contact sensor disposed on the robot detects that the machining tool is in contact with the workpiece, an operation by the operator to turn off remote control is accepted. Then, the position of the control point at the timing when the operator's operation to turn on remote control is accepted after the operating range of the robot 10 is switched from the normal range to the limited range may be set as the reference position of the limited range.

[0058] Furthermore, in the above embodiment, an example was described in which the robot 10 operates in conjunction with an operation action performed by an operator to move the gripper 21, and the movement range of the gripper 21 is limited in accordance with the robot's movement range. However, the present disclosure is not limited thereto. In the present disclosure, the operator's operation action may be detected by a detection unit, such as a sensor, arranged separately from the gripper. Furthermore, the movement range of the gripper may not be limited in accordance with the robot's movement range. That is, when the robot operates within the limited range, the robot may operate in conjunction with an operation action performed on the gripper, but when the robot attempts to operate beyond the limited range, the robot may not operate in conjunction with an operation action performed on the gripper. For example, the robot may operate in conjunction with an operation action detected by an operation device, while the operation device may not operate in conjunction with the robot's movement. Furthermore, instead of limiting the movement range of the gripper when the robot's movement range is switched to the limited range by operating the gripper with an operation drive unit in accordance with the robot's movement, the movement range of the gripper may be limited by controlling the operation drive unit separately from following the robot's movement when the robot's movement range is switched.

[0059] In the above embodiment, the example in which the motion range of the robot 10 is switched while the link with the operation action of the operator is stopped is shown, but the present disclosure is not limited to this. In the present disclosure, the motion range of the robot may be switched while the robot is operating.

[0060] Furthermore, in the above embodiment, an example was described in which an operation to change the size of the restricted range was received by the teaching device 25 as a switching operation unit that receives an operation for teaching the robot 10 to move. However, the present disclosure is not limited to this. In the present disclosure, the operation to change the size of the restricted range may be received by an operation unit that is arranged separately from an operation unit that receives an operation to switch the robot's movement range. Furthermore, the operation to switch the robot's movement range may be arranged separately from an instruction operation unit that receives an operation for teaching the robot to move. That is, at least one of the operation to change the size of the restricted range, the operation to switch the movement range, and the operation to switch remote control on and off may be received by an operation unit different from the teaching device that teaches the robot to move. For example, at least one of the operation to change the size of the restricted range, the operation to switch the movement range, and the operation to switch remote control on and off may be received by a keyboard, a pointing device such as a mouse, or a touch panel that also serves as a display unit such as a monitor.

[0061] In the above embodiment, the robot 10 has a processing tool 12 that performs grinding disposed on the robot arm 11 as an end effector, and the robot 10 performs grinding on a workpiece 101, but the present disclosure is not limited to this. In the present disclosure, the processing tool disposed on the robot may perform processing other than grinding, such as drilling, cutting, or polishing. The robot may also perform handling other than processing, such as assembly, transportation, or inspection. In addition, the operating range may be switched from a normal range to a limited range in a medical robot, rather than an industrial robot.

[0062] In the above embodiment, an example is shown in which the operation of the robot 10 is switched between the tool coordinate system and the base coordinate system, but the present disclosure is not limited to this. In the present disclosure, the robot may be configured to operate in only one of the tool coordinate system and the base coordinate system.

[0063] Furthermore, in the above embodiment, an example has been shown in which the operation device 20 is linked with the robot 10 by the driving force of the drive unit 23 as an operation drive unit, but the present disclosure is not limited to this. In the present disclosure, an operation drive unit that links the operation device with the robot may not be provided. Furthermore, when contact by the robot is detected, information notifying that contact has been detected may be displayed on a display device such as a display. Furthermore, the detection of contact by the robot may be notified by outputting audio information or by turning on or blinking a lighting device such as an LED (Light-Emitting Diode).

[0064] Furthermore, in the above embodiment, an example has been described in which the robot 10 includes six vertical joints and the operation device 20 includes link members 22 with a parallel link structure, but the present disclosure is not limited to this. In the present disclosure, the robot may include joints with five or fewer axes or seven or more axes. A horizontally articulated robot may also be used. The robot may have a drive mechanism other than a robot arm with a parallel link structure or a serial link structure, such as a linear motion mechanism. The operation device may also include link members with a serial link structure rather than a parallel link structure. In other words, the operation device may include a vertically articulated or horizontally articulated robot. The operation device may also include an input device such as an operation unit with multiple switches or a joystick.

[0065] In the above embodiment, the sensor 13 serving as a contact sensor for detecting a contact force on the robot 10 is a force sensor, but the present disclosure is not limited to this. In the present disclosure, instead of a contact sensor for detecting a contact force, a capacitance sensor, a photoelectric sensor, or the like may be disposed to detect that the robot has come into contact with a workpiece.

[0066] In the above embodiment, the normal range and limited range, which are the operating ranges of the robot 10, are set by setting the size in each of the three-dimensional directions relative to the reference position. However, the present disclosure is not limited to this. In the present disclosure, the operating range may be set not only in terms of the size in each of the three-dimensional directions but also in terms of the rotation angle about each of the three-dimensional directions as the rotation axis. That is, the limited range may be set by setting six set values ​​for the size in each of the three-dimensional directions and the rotation angle about each of the three-dimensional directions as the rotation axis. Furthermore, the range of set values ​​for the limited range may be set by setting not only negative values ​​but also positive values. Furthermore, the operating range of a spherical robot may be set by setting a radial distance from the reference position. Furthermore, the operating range may be set by setting multiple reference positions. For example, the normal range or limited range in the vertical direction may be set by setting a lower limit reference position below the vertical direction and an upper limit reference position above the vertical direction. Furthermore, the spatial position of the plane that bounds the operating range may be set by setting three different reference positions. For example, when placing a machining tool that performs grinding processing on a robot, three points on the reference surface of the workpiece, which is the object to be processed, can be set as reference positions, and a limited range can be set so that grinding processing is performed only on the parts that protrude from the reference surface.

[0067] In the above embodiment, the control unit 19 that controls the operation of the robot 10 and the control unit 29 that controls the operation of the operation device 20 are arranged separately from each other, but the present disclosure is not limited to this. In the present disclosure, the operation of the robot and the operation of the operation device may be controlled by a common control unit.

[0068] The functions of the elements disclosed herein can be performed using circuits or processing circuits, including general-purpose processors, special-purpose processors, integrated circuits, ASICs (Application Specific Integrated Circuits), conventional circuits, and / or combinations thereof, configured or programmed to perform the disclosed functions. A processor is considered a processing circuit or circuit because it includes transistors and other circuitry. In this disclosure, a circuit, unit, or means is hardware that performs the recited functions or hardware that is programmed to perform the recited functions. The hardware may be hardware disclosed herein or other known hardware that is programmed or configured to perform the recited functions. Where the hardware is a processor, which is considered a type of circuit, the circuit, means, or unit is a combination of hardware and software, and the software is used to configure the hardware and / or processor.

[0069] Aspects It will be appreciated by those skilled in the art that the exemplary embodiments described above are examples of the following aspects.

[0070] (Aspect 1) A robot system comprising: an operating device that detects an operating action by an operator; a robot that operates in conjunction with the operating action detected by the operating device; and a control unit that switches the operating range of the robot from a preset normal range to a limited range that is smaller than the normal range.

[0071] (Aspect 2) The robot system according to Aspect 1, further comprising a switching operation unit that receives an operation to switch a motion range of the robot, wherein the control unit switches the motion range of the robot from the normal range to the limited range based on the operation received by the switching operation unit.

[0072] (Aspect 3) The robot system according to Aspect 1 or Aspect 2, wherein the control unit sets a reference position of a control point set for the robot, and sets the limited range by limiting a movement range of the control point from the set reference position.

[0073] (Aspect 4) The robot system according to Aspect 3, wherein the robot includes a contact sensor that detects a contact force applied to the robot, and the control unit sets the position of the control point at a timing when the contact force is detected as the reference position based on a detection result from the contact sensor.

[0074] (Aspect 5) A robot system according to any one of Aspects 1 to 4, wherein the operating device includes a gripping portion to be gripped by the operator and detects an operating action by the operator to move the gripping portion, the robot operates in conjunction with the operating action by the operator to move the gripping portion, and the control unit limits the range of movement of the gripping portion in accordance with each of the normal range and the limited range of movement of the robot.

[0075] (Aspect 6) The robot system according to any one of Aspects 1 to 5, wherein the control unit switches the motion range of the robot in a state where linkage with the operation motion of the robot detected by the operation device is stopped.

[0076] (Aspect 7) The robot system according to Aspect 2, further comprising a memory unit that stores a preset size of the limited range, wherein the switching operation unit accepts an operation to change the size of the limited range, and the control unit changes the size of the limited range stored in the memory unit based on the operation accepted by the switching operation unit.

[0077] (Aspect 8) The robot system according to Aspect 2, wherein the switching operation unit receives an operation for teaching the robot an operation, and the control unit switches the motion range of the robot based on the operation for switching the motion range received by the switching operation unit that receives the operation for teaching.

[0078] (Aspect 9) The robot system according to any one of Aspects 1 to 8, wherein the robot includes a robot arm to which a processing tool that performs grinding is attached, and the control unit switches a movement range of the processing tool by switching an operating range of the robot.

[0079] (Aspect 10) A robot system according to any one of Aspects 1 to 9, wherein the robot includes a robot arm to which a processing tool is attached, and the control unit switches between operating the robot in a tool coordinate system based on an orientation of the processing tool and operating the robot in a base coordinate system based on an absolute three-dimensional space regardless of the orientation of the processing tool, and switches the operating range of the robot from the normal range to the limited range for each of the operation of the robot in the tool coordinate system and the operation of the robot in the base coordinate system.

[0080] (Aspect 11) A robot system according to any one of Aspects 1 to 10, wherein the robot includes a contact sensor that detects a contact force applied to the robot, the operation device includes an operation drive unit that links the operation device with the robot, and the control unit operates the operation drive unit in conjunction with the contact force based on a detection result detected by the contact sensor.

[0081] (Aspect 12) The robot system according to any one of Aspects 1 to 11, wherein the robot is remotely controlled in conjunction with an operation action detected by the operation device, and the control unit switches a motion range of the robot, which is remotely controlled in conjunction with the operation action detected by the operation device, from the normal range to the limited range.

Claims

1. A robot system comprising: an operating device that detects an operating action by an operator; a robot that operates in conjunction with the operating action detected by the operating device; and a control unit that switches the motion range of the robot from a preset normal range to a restricted range that is smaller than the normal range.

2. A robot system as described in claim 1, further comprising a switching operation unit that accepts an operation to switch the motion range of the robot, wherein the control unit switches the motion range of the robot from the normal range to the restricted range based on the operation accepted by the switching operation unit.

3. A robot system as described in claim 1, wherein the control unit sets a reference position of a control point set for the robot and sets the limited range by limiting the operating range of the control point from the set reference position.

4. The robot system of claim 3, wherein the robot includes a contact sensor that detects a contact force applied to the robot, and the control unit sets the position of the control point at the time when the contact force is detected as the reference position based on the detection result from the contact sensor.

5. The robot system of claim 1, wherein the operating device includes a gripping part that is gripped by the operator and detects an operating action by the operator to move the gripping part, the robot operates in conjunction with the operating action by the operator to move the gripping part, and the control unit limits the movement range of the gripping part in accordance with each of the operating ranges of the robot, the normal range and the limited range.

6. The robot system according to claim 1, wherein the control unit switches the motion range of the robot while linkage with the operating motion of the robot detected by the operating device is stopped.

7. A robot system as described in claim 2, further comprising a memory unit which stores the size of the limit range that has been set in advance, wherein the switching operation unit accepts an operation to change the size of the limit range, and the control unit changes the size of the limit range stored in the memory unit based on the operation accepted by the switching operation unit.

8. A robot system as described in claim 2, wherein the switching operation unit accepts an operation for teaching the robot an operation, and the control unit switches the motion range of the robot based on an operation for switching the motion range accepted by the switching operation unit which accepts the operation for teaching.

9. The robot system according to claim 1, wherein the robot includes a robot arm to which a processing tool for performing grinding is attached, and the control unit switches the movement range of the processing tool by switching the operating range of the robot.

10. A robot system as described in claim 1, wherein the robot includes a robot arm to which a processing tool is attached, and the control unit switches between operating the robot in a tool coordinate system based on the orientation of the processing tool and operating the robot in a base coordinate system based on an absolute three-dimensional space regardless of the orientation of the processing tool, and switches the operating range of the robot from the normal range to the limited range for each of the operation of the robot in the tool coordinate system and the operation of the robot in the base coordinate system.

11. The robot system of claim 1, wherein the robot includes a contact sensor that detects a contact force applied to the robot, the operation device includes an operation drive unit that links the operation device with the robot, and the control unit operates the operation drive unit in conjunction with the contact force based on the detection result detected by the contact sensor.

12. The robot system of claim 1, wherein the robot is linked to an operating action detected by the operating device via remote control, and the control unit switches the operating range of the robot linked to the operating action detected by the operating device via remote control from the normal range to the restricted range.

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