Robot control device

Abstract

This robot control device includes a control device body that receives a signal from a first change device that changes an operation parameter for driving a robot in a direct teaching operation and a signal from a second change device that changes the operation parameter. The control device body comprises: a selection unit that selects from between the operation parameter signal from the first change device and the operation parameter signal from the second change device an operation parameter signal from one of the change devices; and a setting unit that sets the operation parameter on the basis of the operation parameter signal corresponding to the operation of the one of the change devices.

Description

Robot control device

[0001] The present disclosure relates to a robot control device.

[0002] A robotic device equipped with a robot and a work tool is driven based on an operation program. The operation program contains operation command statements for driving the robot or the work tool. To generate the operation command statements, it is necessary to set teaching points related to the position and orientation of the robot.

[0003] To teach a teaching point, an operator can manually drive the robot using a teaching operation panel. The operator can teach the desired position and orientation of the robot as the teaching point. In recent years, it has become known that in teaching operations, an operator directly pushes or pulls the robot to change the position and orientation of the robot. The operation in which an operator directly moves the robot to teach a teaching point is called a direct teaching operation.

[0004] JP 2019-63916 A International Publication No. WO2011 / 036865A1 JP 1-271189 A

[0005] A robot that performs direct teaching operations is equipped with a sensor for detecting an external force with which a worker operates the robot. The robot control device can drive the robot based on the magnitude and direction of the external force. To perform direct teaching operations, the robot control device must have predetermined motion parameters for the direct teaching operations. For example, the direction in which the robot is driven relative to the direction of the external force and the maximum speed of the robot must be set as motion parameters in advance. Since the motion parameters are set by operating a teaching operation panel, there is a problem in that it takes time to set the motion parameters. For this reason, it is preferable to improve the workability of changing the motion parameters for direct teaching operations.

[0006] One aspect of the present disclosure is a robot control device that performs a direct teaching operation in which an operator directly operates a robot to teach a teaching point. The robot control device includes a control device main body that receives a signal from a first change device that changes an operation parameter for driving the robot by the direct teaching operation and a signal from a second change device that changes the operation parameter. The control device main body includes a selection unit that selects an operation parameter signal from one of the operation parameter signals from the first change device and the second change device. The control device main body includes a setting unit that sets the operation parameter based on the operation parameter signal corresponding to the operation of the one change device. The control device main body includes a manual command unit that sends a command to drive the robot based on the operation parameter set by the setting unit.

[0007] 1 is a schematic diagram of a robot device according to a first embodiment. FIG. 2 is a block diagram of the robot device according to the first embodiment. FIG. 3 is a perspective view of a worker and a robot when performing a direct teaching operation. FIG. 4 is an enlarged perspective view of an internal operation switch arranged on the wrist of the robot. FIG. 5 is a perspective view of the robot illustrating the direction in which the robot drives in a direct teaching operation. FIG. 6 is a control flowchart for setting operation parameters for a direct teaching operation in the first embodiment. FIG. 7 is an enlarged perspective view of a robot of a robot device according to a second embodiment. FIG. 8 is a block diagram of a robot device according to the second embodiment. FIG. 9 is a schematic plan view of a teaching operation panel. FIG. 10 is an image displayed on the display unit when operation parameters are set on the teaching operation panel. FIG. 11 is an image displayed on the display unit of the teaching operation panel when operation parameters are set with external operation switches. FIG. 12 is an image displayed on the display unit of the teaching operation panel when some types of operation parameters are set with external operation switches. FIG. 13 is an image displayed on the display unit of the teaching operation panel for a parameter group of operation parameters. FIG. 14 is an image displayed on the display unit of the teaching operation panel for setting operation parameters included in a parameter group. FIG. 15 is a perspective view of a robot and a hand of another robot device according to the second embodiment.

[0008] 1 to 6, a robot control device and a robot device according to a first embodiment will be described. The robot device of this embodiment includes a work tool, a robot, and a robot control device. The robot control device is configured to control the operation of the work tool and the operation of the robot.

[0009] FIG. 1 shows a perspective view of a robot device according to this embodiment. FIG. 2 shows a block diagram of the robot device according to this embodiment. The robot device performs a predetermined task based on a predetermined operation program. With reference to FIGS. 1 and 2, a robot device 8 according to this embodiment performs the task of grasping a workpiece and transporting it to a predetermined position. The robot device 8 includes a hand 2 as a work tool and a robot 1 that moves the hand 2.

[0010] The hand 2 of this embodiment grasps a workpiece by pinching it between two fingers. Any work tool can be attached to the robot depending on the work to be performed by the robot device. For example, if the robot device performs arc welding, a welding torch can be attached to the robot as a work tool.

[0011] The robot 1 of this embodiment is an articulated robot including a plurality of joints. The robot 1 includes a swivel base 13 supported on a base 14. The base 14 is fixed to a platform 88. The swivel base 13 rotates relative to the base 14. The robot 1 includes an upper arm 11 and a lower arm 12 that are rotatably supported via joints. The upper arm 11 rotates around a rotation axis that is parallel to the direction in which the upper arm 11 extends.

[0012] The robot 1 includes a wrist 15 that is rotatably connected to the end of the upper arm 11. The wrist 15 includes a rotatable flange 16. The hand 2 is supported by the flange 16. The robot 1 in this embodiment has six joint axes, but is not limited to this. Any robot that can move a work tool can be used.

[0013] The robot 1 includes a robot drive device that changes the position and posture of the robot 1. The robot drive device includes a robot drive motor 19 that drives components such as the arm and wrist. The hand 2 includes a tool drive device that drives the hand 2. The tool drive device includes a pressure pump, a valve, and the like for driving the fingers of the hand 2.

[0014] The robot 1 is provided with a position detector 18 that outputs the rotational position of the joint axis of the robot 1. The position detector 18 is configured, for example, by an encoder attached to an electric motor. The robot control device 5 can detect the position and posture of the robot 1 from the output of the position detector 18.

[0015] The robot device 8 includes a robot control device 5. The robot control device 5 includes a control device main body 4 including an arithmetic processing device (computer) having a CPU (Central Processing Unit) as a processor. The arithmetic processing device has a RAM (Random Access Memory) and a ROM (Read Only Memory), etc., which are connected to the CPU via a bus. An operation program 32 includes operation commands for driving the robot 1 and the hand 2. In this embodiment, the robot 1 and the hand 2 transport a workpiece by being driven based on the operation program 32.

[0016] The control device main body 4 includes a storage unit 42 that stores information related to the control of the robot device 8. The storage unit 42 can be configured with a non-transitory storage medium capable of storing information. For example, the storage unit 42 can be configured with a storage medium such as a volatile memory, a non-volatile memory, a magnetic storage medium, or an optical storage medium. A robot operation program 32 that defines the robot's operations is stored in the storage unit 42.

[0017] The control device main body 4 includes an operation control unit 43 that outputs operation commands for the robot. The control device main body 4 also includes a robot drive unit 45 including an electrical circuit that supplies electricity to the robot drive device, and a tool drive unit 44 including an electrical circuit that supplies electricity to the tool drive device. The operation control unit 43 outputs operation commands for driving the robot 1 to the robot drive unit 45 based on the operation program 32. The robot drive unit 45 supplies electricity to the robot drive motor 19 based on the operation commands. The operation control unit 43 outputs operation commands for driving the hand 2 to the tool drive unit 44 based on the operation program 32. The tool drive unit 44 supplies electricity to the hand drive device based on the operation commands.

[0018] The operation control unit 43 corresponds to a processor that operates in accordance with the operation program 32. The operation control unit 43 is configured to be able to read information stored in the storage unit 42. The processor functions as the operation control unit 43 by reading the operation program 32 and carrying out the control defined in the operation program 32.

[0019] Figure 3 shows a perspective view of the robot and the worker when the worker is performing a direct teaching operation. Referring to Figures 1 to 3, the robot device 8 of this embodiment is configured so that a teaching point can be taught by a direct teaching operation. In a direct teaching operation, the worker 87 changes the position and posture of the robot by directly pushing or pulling the robot 1 or the hand 2. When the position and posture of the robot reach the desired position and posture, the position and posture of the robot are stored in the memory unit 42 as a teaching point. In this example, the worker 87 changes the position and posture of the robot by grasping and moving the hand 2 with his or her hand.

[0020] The robot device 8 is provided with a sensor for detecting an external force applied to the robot 1 by an operator 87 during a direct teaching operation. In this embodiment, a force sensor 22 is disposed between the flange 16 and the hand 2.

[0021] Any sensor, such as a sensor including a strain sensor or a capacitance sensor, can be used as the force sensor 22. A sensor capable of detecting force components in six-axis directions can be used as the force sensor 22. For example, the force sensor 22 detects forces in the directions of three orthogonal axes (X-axis, Y-axis, and Z-axis) of a sensor coordinate system and moments (Mx, My, Mz) as forces in the directions of axes around the three axes (W-axis, P-axis, and R-axis).

[0022] The sensor for detecting the external force applied by the worker can be placed at any position. For example, a force sensor may be placed on the base. Any sensor having the function of detecting an external force can be used. For example, the sensor for detecting an external force can be configured as a torque sensor placed on each drive axis of the robot.

[0023] 1 and 2, the robot control device 5 of this embodiment functions as a teaching device. The control device main body 4 generates an operation program 32 based on teaching points. The storage unit 42 stores a generation program 33 for generating the operation program 32 by a direct teaching operation. The generation program 33 corresponds to a computer program of the teaching device for performing the direct teaching operation.

[0024] The control device main body 4 includes a program generation unit 60 that generates and modifies the operation program 32. The program generation unit 60 is driven based on the generation program 33. In the direct teaching operation, when the worker applies force to a component of the robot 1, the program generation unit 60 performs control to change the position and posture of the robot 1 so that the component of the robot 1 moves based on the direction in which the force is applied.

[0025] The program generation unit 60 includes a force detection unit 66 that detects the direction and magnitude of the force and torque applied to the component members by the worker. The force detection unit 66 detects the magnitude and direction of the external force applied to the robot 1 based on the output of the force sensor 22.

[0026] The program generation unit 60 includes a manual command unit 67 that generates a motion command for driving the robot 1 based on the magnitude and direction of the external force detected by the force detection unit 66 and the motion parameters of the direct teaching operation. The manual command unit 67 generates a motion command for driving the robot 1 so that the robot 1 drives based on the external force applied by the worker. The manual command unit 67 sends a motion command for driving the robot drive motor 19 to the motion control unit 43. The motion control unit 43 drives the robot 1 based on the command signal from the manual command unit 67 while the direct teaching operation is being performed. In this way, the worker can directly operate the robot 1 to change the position and posture of the robot to generate teaching points.

[0027] The program generation unit 60 includes a state acquisition unit 61 that acquires the position and posture of the robot 1. The state acquisition unit 61 detects the position and posture of the robot 1 based on the output of the position detector 18. The program generation unit 60 includes a teaching point setting unit 62 that sets the position and posture of the robot 1 acquired by the state acquisition unit 61 as teaching points. The program generation unit 60 includes a command statement generation unit 63 that generates command statements for operations included in the operation program 32 based on the teaching points set by the teaching point setting unit 62.

[0028] The program generation unit 60 corresponds to a processor that operates based on the generation program 33. The processor functions as the program generation unit 60 by carrying out the control defined in the generation program 33. Each of the units, the state acquisition unit 61, the teaching point setting unit 62, the command statement generation unit 63, the force detection unit 66, and the manual command unit 67, corresponds to a processor that operates based on the generation program 33. The processor functions as each of the units by carrying out the control defined in the generation program 33. Furthermore, the operation control unit 43 corresponds to a processor that operates based on the generation program 33.

[0029] The robot control device 5 of this embodiment is equipped with a change device that changes the operation parameters for driving the robot 1 through direct teaching operations. In this embodiment, the robot control device 5 is equipped with multiple change devices. The robot control device 5 includes a built-in operation switch 23 as a first change device and an external computer 54 as a second change device. Each change device is connected to the control device main body via a communication line or wirelessly.

[0030] The motion parameters for performing direct teaching operations include parameters for defining and limiting the motion of the robot during the direct teaching operations. For example, the motion parameters include the direction in which the robot can move, the maximum speed of the robot, a gain for determining the speed of the robot from an external force generated by the operator's operation, and a gain for determining the acceleration of the robot from an external force generated by the operator's operation. Before performing the direct teaching operations, the operator must set these motion parameters related to the driving of the robot.

[0031] FIG. 4 is a perspective view of the built-in operation switch of the robot device according to the first embodiment of the present invention. The built-in operation switch is an operation switch built into the robot or hand. The built-in operation switch 23 of this embodiment is built into the wrist 15. That is, the built-in operation switch 23 is integrally incorporated into the wrist 15.

[0032] The built-in operation switch 23 has a button 23a arranged thereon for changing the settings of the operating parameters. The built-in operation switch 23 is configured to be able to communicate with the program generation unit 60 of the control device main body 4 via a communication line. A signal generated when the button 23a is pressed is transmitted to the program generation unit 60. The built-in operation switch 23 of this embodiment has a plurality of buttons 23a arranged thereon.

[0033] In the robot control device of the comparative example, the motion parameters of the direct teaching operation are changed using a teaching operation panel connected to the control device main body. When changing the motion parameters, the operator releases his / her hands from the robot and holds the teaching operation panel to perform the operation. In contrast, in this embodiment, the operator can operate each button 23a while grasping the spherical portion of the wrist 15. The operator can set the motion parameters without moving his / her hands much from the hand 2 that is being held to change the position and posture of the robot. This allows the motion parameters to be set in a short time, improving the workability of the direct teaching operation. Here, setting the motion parameters in this embodiment includes newly defining motion parameters and changing motion parameters.

[0034] Each button 23a of the built-in operation switch 23 can correspond to one operation parameter. For example, one button 23a can correspond to the maximum speed of the robot. Multiple maximum speeds are predetermined and stored in the memory unit 42. Maximum speed values ​​are, for example, 50 mm / sec, 100 mm / sec, and 250 mm / sec. The built-in operation switch 23 is configured to emit a signal that sequentially changes the maximum speed setting value each time the maximum speed button 23a is pressed. Alternatively, the built-in operation switch can be configured so that pressing the maximum speed button 23a printed with a plus mark increases the maximum speed setting value, and pressing the button 23a printed with a minus mark decreases the maximum speed setting value.

[0035] The robot 1 of this embodiment includes a light 24 as a light-emitting member that lights up or goes out depending on the operation parameters set by the built-in operation switch 23. In this embodiment, a plurality of lights 24 are provided. The lights 24 are, for example, light-emitting diodes (LEDs). The lights 24 of this embodiment are provided adjacent to the built-in operation switch 23. The lights 24 are also provided near the buttons 23 a of the built-in operation switches 23.

[0036] The operating parameter settings may be made identifiable by the lighting pattern of the light 24. For example, a lighting pattern in which the light 24 flashes while it is lit may be used. The number of flashes may be changed in accordance with the maximum speed or other settings. Alternatively, the operating parameter settings may be confirmed by the external computer 54.

[0037] 1 and 2, the second change device of the robot device 8 according to the first embodiment is an external computer 54 connected to the control device main body 4 via a communication line 59. The external computer 54 according to the present embodiment is a notebook personal computer. The external computer 54 is configured by an arithmetic processing unit (computer) having a CPU as a processor.

[0038] The external computer 54 includes a storage unit 58 that stores information related to the robot device 8. The storage unit 58 can be configured with a non-transitory storage medium capable of storing information. For example, the storage unit 58 can be configured with a storage medium such as a volatile memory, a non-volatile memory, a magnetic storage medium, or an optical storage medium. The external computer 54 has a display unit 55 that displays information related to the operating parameters of the direct teaching operation. The display unit 55 can be configured with a display panel such as a liquid crystal panel. The external computer 54 includes an input unit 56 through which the operator inputs any information. The input unit 56 can be configured with an input member such as a keyboard, a mouse, or a dial.

[0039] The external computer 54 has an arithmetic processing unit 57 that acquires information through the operation of the input unit 56, performs internal arithmetic processing, and controls images displayed on the display unit 55. The arithmetic processing unit 57 corresponds to a CPU as a processor. The processor functions as the arithmetic processing unit 57 by being driven in accordance with a predetermined program. The external computer 54 is configured so that the operator can directly set operating parameters for teaching operations by operating the input unit 56.

[0040] The external computer 54 can employ packet communication as a communication method for communicating with the control device main body 4. For example, a signal transmitted from the external computer 54 to the program generating unit 60 can be transmitted as a packet.

[0041] Furthermore, the external computer 54 can send and receive information in the form of numerical values ​​to and from the control device main body. For example, the numerical value of the robot's maximum speed can be sent from the external computer 54 to the program generation unit 60. Furthermore, the directions in which the robot can move can be defined by numbers, and the directions in which the robot can move can be sent from the external computer 54 to the program generation unit 60. For example, the number zero can be defined as movement in any direction. Then, the directions in which the robot can move can be sent to the program generation unit 60 using these numbers.

[0042] In this embodiment, the second change device is a notebook computer, but is not limited to this. The second change device can be configured as any change device different from the first change device and the teaching pendant. For example, the external computer can be configured as a tablet terminal.

[0043] The control device main body 4 receives an operating parameter signal from the built-in operation switch 23 as a first changing device and an operating parameter signal from the external computer 54 as a second changing device. The control device main body 4 includes a selection unit 64 that selects the operating parameter signal from one of the built-in operation switch 23 and the external computer 54.

[0044] In the robot control device 5, when the selection unit 64 is receiving a signal from the external computer 54, it stops receiving a signal from the built-in operation switch 23. For example, when the worker is setting operation parameters using the external computer 54, the selection unit 64 stops receiving a signal of the worker's operation of the built-in operation switch 23.

[0045] In this embodiment, the selection unit 64 automatically selects the change device that will change the operating parameters, but this is not limiting. The selection unit may be configured so that the operator can specify the change device that will receive the operating parameter signal.

[0046] The program generation unit 60 includes a setting unit 65 that sets the operation parameters based on the signal of the operation parameter corresponding to the operation of one of the change devices selected by the selection unit 64. Each of the selection unit 64 and the setting unit 65 corresponds to a processor that operates based on the generation program 33. The processor performs the control defined in the generation program 33, thereby functioning as each unit.

[0047] In this way, the selection unit 64 can stop receiving signals from the first change device when it is receiving a signal from the second change device. The robot device 8 receives a signal for changing operation parameters from the external computer 54 with priority over the built-in operation switch 23. The program generation unit 60 sets operation parameters based on a signal corresponding to the operation of the external computer 54 by the worker.

[0048] By implementing this control, the operating parameters that can be set by the second change device can be preferentially set by operating the second change device. The operating parameters that cannot be set by the second change device can be set using the first change device. The operating parameters set by the setting unit 65 are saved in an operating parameter file stored in the storage unit 42.

[0049] In actual teaching work, the manual command unit 67 uses the operation parameters set in the setting unit 65 to send commands to the operation control unit 43 to drive the robot 1 in response to direct operation of the robot by the worker.

[0050] 2 and 4 , in this embodiment, when setting unit 65 receives a signal from built-in operation switch 23, selection unit 64 turns on light 24. This allows the operator to know that the operating parameters can be set using built-in operation switch 23. When setting unit 65 does not receive a signal from built-in operation switch 23, selection unit 64 turns off light 24. This allows the operator to know that the operating parameters cannot be set using built-in operation switch 23.

[0051] The built-in operation switch 23 may include a plurality of buttons 23a for changing a plurality of types of operation parameters. Also, a plurality of lights 24 may be built into the robot 1. The plurality of lights 24 and the plurality of buttons 23a are formed to correspond to a plurality of types of operation parameters.

[0052] The setting unit 65 can turn off the lights 24 corresponding to the operating parameters for which it receives signals from the external computer 54, and can turn on the lights 24 corresponding to the operating parameters for which it receives signals from the built-in operation switches 23. That is, the selection unit 64 can turn on the lights 24 corresponding to the operating parameters to be changed by the built-in operation switches 23, and can turn off the lights 24 corresponding to the operating parameters to be changed by the external computer 54.

[0053] For example, the first button 23a and the first light 24 of the built-in operation switch 23 are determined as the button and light corresponding to the maximum speed of the robot, and the second button 23a and the second light 24 of the built-in operation switch 23 are determined as the button and light corresponding to the direction in which the robot can move.

[0054] Here, there are cases where the maximum speed of the robot can be changed in the external computer 54, but the direction in which the robot can move cannot be changed. In this case, the selection unit 64 can receive a signal of an operation parameter related to the maximum speed of the robot from the external computer 54, and can receive an operation parameter related to the direction in which the robot can move from the built-in operation switch 23.

[0055] That is, when multiple types of operation parameters are defined, the selection unit 64 can select an operation parameter signal received from the second change device. The selection unit 64 can select an operation parameter signal other than the operation parameter received from the second change device from a signal received from the first change device. The setting unit 65 can set the operation parameters received from the second change device based on the operation of the second change device, and can set operation parameters other than the operation parameters received from the second change device based on the operation of the first change device.

[0056] Furthermore, the selection unit 64 can turn off the light 24 corresponding to the maximum speed of the robot and turn on the light 24 corresponding to the direction in which the robot can move. By looking at the lighting state of the light 24, the worker can know which buttons of the built-in operation switch 23 can be operated for the operating parameters.

[0057] Figure 5 shows a perspective view of the robot, illustrating the directions in which the robot can operate during direct teaching operations. A tool coordinate system 90 is set in the robot device 8. In this embodiment, the origin of the tool coordinate system 90 is set to the tool tip point of the hand 2. The position and orientation of the tool coordinate system 90 change together with the hand 2. A world coordinate system 89 is set in the robot device 8. The world coordinate system 89 is a coordinate system in which the position of the origin and the orientation of the coordinate axes do not change even when the robot 1 is driven. The position of the tool tip point in the world coordinate system 89 can be used as the position of the robot 1. The orientation of the tool coordinate system 90 relative to the world coordinate system 89 can be used as the orientation of the robot 1.

[0058] Movement when an external force is applied in a direct teaching operation can include translational movement in a direction determined by the tool coordinate system 90. For example, as a translational movement, the robot 1 can be driven so that the origin of the tool coordinate system 90 moves only in the direction of one of the coordinate axes (X-axis, Y-axis, or Z-axis) of the tool coordinate system 90. For example, if the direction of the external force applied by the operator is close to the direction in which the Y-axis of the tool coordinate system extends, the robot 1 can be driven so that the tool tip point moves in the Y-axis direction without moving in the X-axis and Z-axis directions.

[0059] The operable directions of the robot may include directions of rotation around a predetermined rotation axis. For example, the robot 1 may be driven so that the hand 2 rotates around one coordinate axis without moving the origin of the tool coordinate system 90. For example, the position and posture of the robot 1 may be changed so that the hand 2 rotates around the Y axis of the tool coordinate system 90, using the Y axis as the rotation axis.

[0060] Furthermore, one of the multiple parallel movement directions and multiple rotational movement directions can be selected as the direction in which the robot can operate. For example, the robot can be driven so that the tool coordinate system 90 moves in one predetermined direction regardless of the direction in which an external force is applied.

[0061] The robot's operable directions can be determined as a combination of parallel and rotational movements. Furthermore, the direction can be set to follow the operator's movement of moving or rotating the hand 2 in any direction. In other words, the operator can move along any curve and change the posture of the hand 2 in any direction.

[0062] The maximum speed of the robot can be, for example, the maximum movement speed of a predetermined point on the robot or work tool. For example, the maximum movement speed of the tool tip point can be used. Alternatively, the rotation speed around the robot's drive axis can be used. The gain for determining the robot's speed from an external force is a coefficient included in a calculation formula for determining the robot's speed from the magnitude of the external force. The larger the gain, the greater the robot's speed relative to the external force. Similarly, the gain for determining the robot's acceleration from an external force is a coefficient included in a calculation formula for determining the robot's acceleration from the magnitude of the external force. By changing the velocity gain and acceleration gain, the operator's feel when operating the robot in direct teaching operations can be changed. For example, by adjusting the velocity gain and acceleration gain, the operator can adjust the feel of the robot when pushing and driving it by hand, making it feel heavier or lighter.

[0063] A flowchart of the direct teaching operation in the robot apparatus of this embodiment is shown in Fig. 6. The flowchart in Fig. 6 includes a process of setting the operating parameters of the direct teaching operation by using one of the built-in operation switch 23 and the external computer 54.

[0064] In step 91, the selection unit 64 determines whether or not a signal has been input from the external computer 54. If a signal has been input from the external computer 54 in step 91, control proceeds to step 94. The selection unit 64 selects the operating parameter signal from the external computer 54. In step 94, the selection unit 64 turns off the lights 24 arranged around the built-in operation switch 23. Next, in step 95, the setting unit 65 receives a command from the external computer 54 to set the operating parameters. Control proceeds to step 96.

[0065] On the other hand, if a signal from the external computer 54 is not received in step 91, control proceeds to step 92. That is, if the external computer 54 is not being used to set operating parameters for direct teaching operation, control proceeds to step 92. The selection unit 64 selects the operating parameter signal from the built-in operation switch 23.

[0066] In step 92, the selection unit 64 turns on the light 24 arranged around the built-in operation switch 23. Next, in step 93, the setting unit 65 receives a command from the built-in operation switch 23.

[0067] Next, in step 96, the setting unit 65 sets the operating parameters of the direct teaching operation based on a command from the built-in operation switch 23 or a command from the external computer 54. The setting unit 65 can set the operating parameters of the direct teaching operation in response to the operator's operation of the change device.

[0068] In step 97, the operator performs a direct teaching operation. That is, the force detection unit 66 detects an external force applied by the operator based on the output of the force sensor 22. The manual command unit 67 drives the robot 1 based on the operation parameters, the magnitude of the external force, and the direction of the external force.

[0069] When the robot position and posture become the desired position and posture, the state acquisition unit 61 acquires the robot position and posture. The teaching point setting unit 62 can set the robot position and posture at this time as teaching points. The operator then repeats the above-mentioned work of setting teaching points. The command statement generation unit 63 can then generate command statements for the operation program based on the teaching points. In this way, the program generation unit 60 can generate the operation program 32.

[0070] In the robot device 8, the operating parameters of the robot for direct teaching operations can be set by an external computer 54 in addition to the built-in operation switches 23 built into the robot 1. By adopting this configuration, the operating parameters can be set on the screen of a large display unit 55 of the external computer 54. For example, a list of operating parameters for direct teaching operations can be displayed on the display unit 55, and each operating parameter can be set. This improves the efficiency of the work of setting operating parameters.

[0071] Furthermore, in addition to the operating parameters of the robot device's direct teaching operation, there are cases where parameters of other devices are set. For example, in addition to the operating parameters of the robot device, there are cases where parameters of a machine tool that processes a workpiece are set. Even in such cases, the parameters of the robot and the machine tool can be set at the same time using the external computer 54. This improves the efficiency of the work of setting the operating parameters of the robot device and the parameters of the machine tool.

[0072] The robot control device of this embodiment does not include a teaching pendant, but is not limited to this. A teaching pendant can be connected to the control device main body. In this case, the operating parameters for direct teaching operation can be set on the teaching pendant. The selection unit can select the operating parameter signals for direct teaching operation in the following order of priority: external computer, built-in operation switch, and teaching pendant.

[0073] Second Embodiment A robot control device and a robot device according to a second embodiment will be described with reference to Figures 7 to 15. In the robot device of this embodiment, the first change device and the second change device are different from those in the robot device of the first embodiment.

[0074] Fig. 7 shows an enlarged view of the tip of the robot of the robot device of this embodiment. Fig. 8 shows a block diagram of the robot device of this embodiment. With reference to Figs. 7 and 8, the robot device 9 of this embodiment includes a robot 7 that does not have a built-in operation switch or light. The hand 2 and the control device main body 4 are similar to the hand 2 and the control device main body 4 of the robot device 8 of the first embodiment.

[0075] The first change device of the robot device 9 in this embodiment is a teaching operation panel 49 connected to the control device main body 4. The second change device of the robot device 9 is an external operation switch 25 attached to the robot 7 or the hand 2.

[0076] Fig. 9 shows a plan view of the teaching pendant of the robot device. Referring to Figs. 7 to 9, the teaching pendant 49 includes an arithmetic processing unit 52 that performs calculations and processes information. The arithmetic processing unit 52 includes a CPU as a processor. The teaching pendant 49 includes a display unit 50 for displaying information related to the control of the robot device 9, and an input unit 51 for the operator to input any information. The display unit 50 can be configured with a display panel such as a liquid crystal display panel. The input unit 51 can be configured with input members such as buttons 51a, a keyboard, and a dial.

[0077] The display unit 50 of this embodiment includes a touch panel display panel. The operator can input information by pressing or tracing the button images displayed on the display unit 50. In other words, the touch panel display panel functions as both a display unit and an input unit. The teaching pendant may be configured as a mobile terminal such as a tablet.

[0078] The teaching pendant 49 of this embodiment is configured to communicate with the control device main body 4 via a communication line 53. Alternatively, the teaching pendant may be configured to communicate with the control device main body 4 wirelessly. The teaching pendant 49 is small enough to be carried by an operator. The operator can manually drive the robot 7 by operating the input unit 51. The teaching pendant 49 can specify a teaching point after driving the robot 7.

[0079] The external operation switch 25 is an operation switch attached to the outer surface of the work tool or the outer surface of the robot. The external operation switch may be formed so as to be detachable from the work tool or the robot.

[0080] The external operation switch 25 in this embodiment is attached to the outer periphery of the hand 2. The external operation switch 25 includes a plurality of buttons 25a. One button 25a of the external operation switch 25 can correspond to one operation parameter of the direct teaching operation. For example, the first button 25a may be a button for setting the direction in which the robot can move. Each time this button 25a is pressed, the direction in which the robot can move can be switched. The direction in which the robot can move includes a direction of translation in which the position moves without changing the posture, a direction of rotation in which the posture rotates, a direction that combines translation and rotation, and any direction.

[0081] The second button 25a of the external operation switch 25 can be set as a button for setting the maximum speed of the robot. Each time this button 25a is pressed, the maximum speed can be changed. For example, the maximum speed setting can be changed in the order of 50 mm / sec, 100 mm / sec, and 250 mm / sec. Furthermore, by pressing button 25a when the maximum speed setting is 250 mm / sec, the maximum speed setting can be returned to 50 mm / sec.

[0082] In this way, by controlling the operation parameter settings to change each time a button is pressed, the operation parameters of the direct teaching operation can be changed with a small number of buttons. Also, the operator can easily change the operation parameters of the direct teaching operation.

[0083] In this embodiment, the external operation switch 25 is configured with multiple buttons, but is not limited to this. The external operation switch may be configured to allow input of parameters. For example, the external operation switch may include a slider with a knob. By moving the knob, the set value of the operation parameter can be set to any value. For example, the external operation switch may be configured to allow the maximum speed of the robot to be continuously changed and set to any value.

[0084] As with the robot device 8 of the first embodiment, the selection unit 64 can stop receiving signals from the teaching pendant 49 as the first change device when it is receiving a signal from the external operation switch 25 as the second change device. In other words, it can preferentially receive signals of operating parameters for direct teaching operations from the external operation switch 25.

[0085] 10 shows an image on the display unit when setting operation parameters for direct teaching operation on the teaching operation panel. The display unit 50 displays an image 71 for changing the setting of the operation parameters. When the image 71 is displayed, communication between the external operation switch 25 and the control device main body 4 is stopped. The selection unit 64 selects a signal from the teaching operation panel 49. The setting unit 65 sets the operation parameters for direct teaching operation based on the signal received from the teaching operation panel 49. The image 71 displays a button 71a for changing the direction in which the robot 7 can operate and a slider 71b for changing the maximum speed of the robot.

[0086] The operator can change the direction in which the robot can move by pressing the change button 71 a. The operator can also change the maximum speed by moving the slider 71 b while pressing it. In this way, when an operating parameter signal is not received from the external operation switch 25, the operating parameters can be set on the teaching pendant 49.

[0087] On the other hand, when the external operation switch 25 is driven, the external operation switch 25 transmits a signal to the program generation unit 60 to set operation parameters. The selection unit 64 selects the signal from the external operation switch 25 and stops receiving signals from the teaching pendant 49. The setting unit 65 receives the signal from the external operation switch 25. For example, the external operation switch 25 includes a button 25a for changing the operable direction of the robot and a button 25a for gradually changing the maximum speed of the robot. When the operator presses the button 25a of the external operation switch 25, the setting unit 65 sets the operable direction of the robot or the maximum speed of the robot.

[0088] 11 shows an image of the display unit of the teaching pendant when a signal is received from the external operation switch. The setting unit 65 transmits a signal indicating that it has received a signal from the external operation switch 25 to the teaching pendant 49. When the setting unit 65 receives a signal from the external operation switch 25, the display unit 50 displays an image for changing the operating parameters in a dimmed manner. In this example, signals for all types of operating parameters are received from the external operation switch. The calculation processing unit 52 controls the display of the button 72a and slider 72b in a dimmed manner. This control allows the operator to know that the operating parameters displayed in a dimmed manner on the teaching pendant cannot be changed. The operator can know that the signal from the external operation switch 25 has been selected with priority.

[0089] Here, while the setting unit 65 is receiving a signal from the external operation switch 25, the operator may operate the teaching pendant to change the settings of the operation parameters. For example, the operator may press the button 72a shown in image 72. In this case, the display unit 50 displays an image 73a, as shown in image 73, informing the operator to change the operation parameters using the external operation switch. With this control, if the operator operates the teaching pendant 49 by mistake, the operator can be notified that the change of the operation parameter settings by the teaching pendant 49 has stopped.

[0090] In the example of image 72, multiple types of operation parameters are determined in advance, and the settings of all of the operation parameters are changed using the external operation switch 25. An image for changing all of the operation parameters is displayed in a dimmed form on the display unit 50. On the other hand, there are cases where some of the multiple types of operation parameters are set using the external operation switch 25. In this case, the operation parameters other than the operation parameters set using the external operation switch 25 can be set using the teaching pendant 49.

[0091] 12 shows an image of the display unit when some of the operating parameters are set using the teaching pendant. The selection unit 64 selects the operating parameter signals received from the external operation switch 25, and selects the signals received from the teaching pendant 49 for the operating parameter signals other than the operating parameters received from the external operation switch 25. The setting unit 65 sets the operating parameters received from the external operation switch 25 based on the operation of the external operation switch 25, and sets the operating parameters other than the operating parameters received from the external operation switch 25 based on the operation of the teaching pendant 49.

[0092] At this time, the display unit 50 can display, in a lighter shade, an image for setting the operation parameters to be set by the external operation switch 25. For example, the directions in which the robot can move may be set by the external operation switch 25, and the maximum speed of the robot may be set by the teaching operation panel 49. In this case, in the image 74, the button 74a for switching the directions in which the robot can move is displayed in a lighter shade. On the other hand, the slider 74b for setting the maximum speed of the robot is displayed in a normal shade.

[0093] The operator can change the operable direction by pressing the button 25a of the external operation switch 25. In this case, the currently set operable direction is displayed on the display unit 50. That is, the display of the operation parameters on the display unit 50 changes in response to the operation of the external operation switch 25. On the other hand, the maximum speed of the robot can be changed by pressing and moving the slider 74b displayed on the display unit 50 with a finger.

[0094] Here, when the worker operates the teaching pendant 49 to change the operation parameters set by the external operation switch 25, the display unit 50 displays a notification image 75. The image 75 includes an image 75a notifying the worker to change the setting of the operation parameters by the external operation switch 25. In this example, when the worker presses the button 74a to change the operable direction of the robot, the image 75a can be displayed notifying the worker to operate by the external operation switch 25. This control allows the worker to know that a predetermined operation parameter cannot be operated by the teaching pendant 49.

[0095] In this embodiment, the image for changing the settings of the operation parameters set by the second change device is displayed in a dimmed manner, but this is not limiting. It is also possible to perform control to erase the image for changing the operation parameters set by the second change device.

[0096] In the above embodiment, each operation parameter is newly defined or changed, but the present invention is not limited to this. The operator can define a parameter group in advance that includes multiple types of operation parameters. Then, by switching between parameter groups, multiple operation parameters can be set at once.

[0097] The external operation switch 25 may include a button for switching between parameter groups. The setting unit 65 switches between parameter groups each time the operator presses the button. The setting unit 65 can set the operation parameters included in the parameter group.

[0098] 13 shows an image of the display unit displaying a parameter group. Image 76 displayed by display unit 50 displays multiple types of operation parameters set in the parameter group. The "Input" line indicates that this parameter group can be changed using external operation switch 25. In addition, the robot's movement direction is limited to translation only, and the robot's maximum speed is set to 100 mm / sec. It is also displayed that this parameter group is suitable for teaching palletizing.

[0099] As another example of a parameter group, a parameter group can be set to be used when teaching a posture of a work tool in which the robot can only move in a rotational direction and a small speed gain is set. Multiple groups of such operation parameters can be created.

[0100] 14 shows an image on the display unit when setting a parameter group in this embodiment. Image 77 displayed on display unit 50 is configured so that the direction in which the robot can move can be set using button 77a, and the maximum speed of the robot can be set using slider 77b. Finally, by pressing confirm button 77c, the multiple movement parameters included in the parameter group can be confirmed and stored in memory unit 42. For example, it is possible to add or change the parameter group file saved in memory unit 42.

[0101] In this way, parameter groups are created and stored in advance, and the second change device can switch between parameter groups. Furthermore, the first change device may be configured to switch between parameter groups. This control allows multiple operation parameters to be set at once. The time required to set operation parameters can be reduced. Furthermore, by having an expert create parameter groups in advance, even an operator who is not familiar with how to set operation parameters can select a parameter group appropriate for the task to be performed by the robot device, such as palletizing, and set multiple operation parameters.

[0102] 15 is a perspective view of a robot device equipped with another external operation switch according to this embodiment. The robot device 10 includes a hand 3 as a work tool. The hand 3 includes a plurality of suction cups 3a and a support member 3b that supports the suction cups 3a. The hand 3 is configured to suck a plate-shaped workpiece by reducing the pressure inside the plurality of suction cups 3a. Since the support member 3b of the hand 3 is arranged over a wide area, if the external operation switch is attached near the flange 16 of the robot 7, it would be difficult for the worker to operate the external operation switch.

[0103] In the robot device 10 of this embodiment, the external operation switch 26 is disposed at the end of the hand 3. The external operation switch 26 includes a grip portion 26b that is held by the operator and a plurality of buttons 26a for setting operation parameters. The external operation switch 26 is configured to communicate with the control device main body 4 via a communication line 27.

[0104] The external operation switch 26 can be located at a position away from the robot. This allows for easy modification of the operating parameters of direct teaching operations when working on a large workpiece. By employing the external operation switch as a second modification device, the external operation switch can be located at any position for ease of operation, depending on the shape of the robot or the shape of the hand. The operator can select the location of the external operation switch on the robot device. This makes it easier for the operator to operate the external operation switch, improving the operability of direct teaching operations. The external operation switch can be connected, for example, via a plug-in method. For example, the plug of the external operation switch can be connected to the plug of a communication line located on the robot body for communication with the control device body.

[0105] In addition, in this embodiment, the second change device is an external operation switch attached to a robot or a hand. For example, a work tool having a built-in switch for directly changing the operating parameters of a teaching operation can be used as the second change device in this embodiment. This work tool functions as an external operation switch attached to the robot by being connected to the robot and being able to communicate with the robot's control device. Examples of such work tools include a hand for gripping a workpiece, an applicator for applying a liquid such as adhesive, and a laser head for laser processing.

[0106] Furthermore, the second change device in this embodiment is not limited to an external operation switch attached to the robot or hand, but may be a change device disposed away from the robot and hand. For example, a foot pedal that is designed to be operated by the foot and placed on the installation surface of the robot may be used.

[0107] The other configurations, operations, and effects are the same as those of the first embodiment, and therefore will not be described repeatedly here.

[0108] The robot control device according to at least one of the embodiments described above has the effect of improving the work efficiency of direct teaching operations.

[0109] Although the present disclosure has been described in detail, the present disclosure is not limited to the individual embodiments described above. Various additions, substitutions, modifications, partial deletions, etc. are possible in these embodiments without departing from the gist of the present disclosure or the spirit of the present disclosure derived from the content of the claims and their equivalents. These embodiments can also be implemented in combination. For example, in the above-described embodiments, the order of each operation and the order of each process are shown as examples and are not limited to these. The same applies when numerical values ​​or mathematical expressions are used in the description of the above-described embodiments.

[0110] The following supplementary notes are disclosed regarding the above-described embodiment and modifications.

[0111] (Supplementary Note 1) A robot control device 5, 6 in which an operator directly operates a robot 1 to perform a direct teaching operation to teach a teaching point, the robot control device comprising: a control device main body 4 that receives a signal from a first change device that changes an operation parameter for driving the robot by the direct teaching operation, and a signal from a second change device that changes the operation parameter, the control device main body including: a selection unit 64 that selects an operation parameter signal from one of the operation parameter signals from the first change device and the operation parameter signal from the second change device; a setting unit 65 that sets the operation parameter based on the operation parameter signal corresponding to the operation of the one change device; and a manual command unit 67 that sends a command to drive the robot based on the operation parameter set by the setting unit.

[0112] (Supplementary Note 2) The robot control device according to Supplementary Note 1, wherein the selection unit stops receiving a signal from the first change device when a signal from the second change device is being received.

[0113] (Supplementary Note 3) The robot control device according to Supplementary Note 1, wherein the operation parameters are a direction in which the robot can move, a maximum speed of the robot, a gain for determining the speed of the robot from an external force caused by operation by a worker, or a gain for determining the acceleration from an external force caused by operation by a worker.

[0114] (Appendix 4) A robot control device described in any one of Appendices 1 to 3, wherein the first change device is an internal operation switch 23 built into the robot, and the second change device is an external computer 54 connected to the control device main body.

[0115] (Appendix 5) A robot control device according to Appendix 4, comprising a light-emitting element disposed on the robot, the light-emitting element being lit when the setting unit receives a signal from the built-in operation switch, and the light-emitting element being turned off when the setting unit does not receive a signal from the built-in operation switch.

[0116] (Appendix 6) A robot control device according to Appendix 4, comprising a plurality of light-emitting elements arranged on the robot, wherein the built-in operation switch includes a plurality of buttons for changing a plurality of types of operating parameters, wherein the plurality of light-emitting elements and the plurality of buttons of the built-in operation switch are formed to correspond to the plurality of types of operating parameters, wherein the light-emitting elements corresponding to the operating parameters for which the setting unit receives a signal from an external computer are turned off, and the light-emitting elements corresponding to the operating parameters for which the setting unit receives a signal from the built-in operation switch are turned on.

[0117] (Appendix 7) A robot control device according to any one of Appendices 1 to 3, wherein the first change device is a teaching operation panel 49 connected to the control device main body, and the second change device is an external operation switch 25, 26 attached to the robot or the work tool.

[0118] (Appendix 8) A robot control device according to Appendix 7, wherein the teaching operation panel has a display unit 50 that displays an image for setting operation parameters, and when the setting unit receives a signal from an external operation switch, the display unit erases or dims the image for setting operation parameters.

[0119] (Appendix 9) A robot control device as described in Appendix 7, wherein the teaching operation panel has a display unit 50 that displays an image for setting operation parameters, and when an operator operates the teaching operation panel to change the operation parameters while the setting unit is receiving a signal from the external operation switch, the display unit displays an image 73a notifying the operator to change the operation parameters using the external operation switch.

[0120] (Supplementary Note 10) The robot control device according to Supplementary Note 7, wherein the external operation switch has a button 25a for switching the setting of the operation parameter, and the setting unit switches the operable direction of the robot each time the worker presses the button.

[0121] (Supplementary Note 11) The robot control device according to Supplementary Note 7, wherein the external operation switch has a button 25a for switching the setting of the operation parameter, and the setting unit switches the maximum speed of the robot each time the worker presses the button.

[0122] (Supplementary Note 12) The robot control device according to Supplementary Note 7, wherein parameter groups each including a plurality of types of operation parameters are determined in advance, the external operation switch includes a button 25 a for switching between parameter groups, and the setting unit switches between parameter groups each time the operator presses the button, and sets the plurality of operation parameters included in the parameter group.

[0123] (Supplementary Note 13) A robot control device as described in Supplementary Note 1, wherein a plurality of types of operation parameters are defined, the selection unit selects the operation parameter signal received from the second change device, and selects the operation parameter signal other than the operation parameter received from the second change device as the signal received from the first change device, and the setting unit sets the operation parameter received from the second change device based on the operation of the second change device, and sets the operation parameters other than the operation parameter received from the second change device based on the operation of the first change device.

[0124] (Supplementary Note 14) The robot control device according to Supplementary Note 13, wherein the first change device has a display unit 50 that displays an image for setting the operation parameters, and the display unit erases or fades the image for setting the operation parameters to be set by the second change device.

[0125] (Supplementary Note 15) The robot control device according to Supplementary Note 13, wherein the first change device has a display unit 50 that displays an image for setting an operation parameter, and when the worker operates the first change device to change the operation parameter to be set by the second change device, the display unit displays an image 75a that notifies the worker to change the operation parameter by the second change device.

[0126] 1, 7 Robot 2, 3 Hand 4 Control device main body 5, 6 Robot control device 15 Wrist 23 Built-in operation switch 23a Button 24 Light 25, 26 External operation switch 25a, 26a Button 49 Teaching operation panel 50 Display unit 51 Input unit 54 External computer 55 Display unit 56 Input unit 60 Program generation unit 64 Selection unit 65 Setting unit 67 Manual command unit 71 to 77 Images 71a, 72a, 74a, 77a Button 71b, 72b, 74b, 77b Slider

Claims

1. A robot control device that performs a direct teaching operation in which an operator directly operates a robot to teach it a teaching point, comprising a control device main body that receives a signal from a first modification device that changes an operating parameter for driving the robot by the direct teaching operation and a signal from a second modification device that changes the operating parameter, the control device main body including: a selection unit that selects an operating parameter signal from one of the operating parameter signals from the first modification device and the operating parameter signals from the second modification device; a setting unit that sets the operating parameter based on the operating parameter signal corresponding to the operation of the one of the modifying devices; and a manual command unit that sends a command to drive the robot based on the operating parameter set by the setting unit.

2. The robot control device according to claim 1, wherein the selection unit stops receiving a signal from the first change device when a signal from the second change device is being received.

3. A robot control device as described in claim 1, wherein the operation parameters are a direction in which the robot can move, a maximum speed of the robot, a gain for determining the speed of the robot from an external force caused by an operator's operation, or a gain for determining the acceleration from an external force caused by an operator's operation.

4. A robot control device according to any one of claims 1 to 3, wherein the first change device is an internal operation switch built into the robot, and the second change device is an external computer connected to the control device main body.

5. A robot control device as described in claim 4, further comprising an illuminating member disposed on the robot, the illuminating member being lit when the setting unit receives a signal from the built-in operating switch, and the illuminating member being turned off when the setting unit does not receive a signal from the built-in operating switch.

6. A robot control device as described in claim 4, comprising a plurality of light-emitting members arranged on the robot, the built-in operation switch including a plurality of buttons for changing a plurality of types of the operating parameters, the plurality of light-emitting members and the plurality of buttons of the built-in operation switch being formed to correspond to the plurality of types of the operating parameters, the light-emitting members corresponding to the operating parameters for which the setting unit receives a signal from the external computer being turned off, and the light-emitting members corresponding to the operating parameters for which the setting unit receives a signal from the built-in operation switch being turned on.

7. A robot control device as described in any one of claims 1 to 3, wherein the first change device is a teaching operation panel connected to the control device main body, and the second change device is an external operation switch attached to a robot or a work tool.

8. A robot control device as described in claim 7, wherein the teaching operation panel has a display unit that displays an image for setting the operating parameters, and when the setting unit receives a signal from the external operation switch, the display unit erases or fades the image for setting the operating parameters.

9. A robot control device as described in claim 7, wherein the teaching operation panel has a display unit that displays an image for setting the operating parameters, and when an operator operates the teaching operation panel to change the operating parameters while the setting unit is receiving a signal from the external operation switch, the display unit displays an image notifying the operator to change the operating parameters with the external operation switch.

10. A robot control device as described in claim 7, wherein the external operation switch has a button for switching the setting of the operation parameter, and the setting unit switches the direction in which the robot can operate each time the operator presses the button.

11. A robot control device as described in claim 7, wherein the external operation switch has a button for switching the setting of the operation parameter, and the setting section switches the maximum speed of the robot each time the worker presses the button.

12. The robot control device according to claim 7, wherein parameter groups each including a plurality of types of the operation parameters are predefined, the external operation switch includes a button for switching between parameter groups, and the setting unit switches between parameter groups each time an operator presses the button, and sets the plurality of operation parameters included in the parameter group.

13. A robot control device as described in claim 1, wherein a plurality of types of the operating parameters are defined, the selection unit selects the signal of the operating parameter received from the second change device, and selects the signal of the operating parameter other than the operating parameter received from the second change device as a signal received from a first change device, and the setting unit sets the operating parameter received from the second change device based on the operation of the second change device, and sets the operating parameter other than the operating parameter received from the second change device based on the operation of the first change device.

14. A robot control device as described in claim 13, wherein the first change device has a display unit that displays an image for setting the operating parameters, and the display unit erases or fades the image for setting the operating parameters to be set by the second change device.

15. A robot control device as described in claim 13, wherein the first change device has a display unit that displays an image for setting the operating parameter, and when an operator operates the first change device to change the operating parameter to be set by the second change device, the display unit displays an image notifying the operator to change the operating parameter by the second change device.

Images