Robot system, parallel linkage mechanism, control method, control device, program and storage medium

Abstract

The robot system described in this embodiment includes a multi-jointed arm mechanism, a parallel linkage mechanism, an end effector, a detector, and a control device. The control device performs a first action of moving the arm mechanism and a second action of moving the parallel linkage mechanism. Between the first and second actions, the control device performs: a calculation process, calculating the displacement of the control point's posture up to the working posture based on the detector's detection results; and a determination process, determining whether the displacement is within the movable range of the movable part. If the displacement exceeds the movable range, the control device performs the second action after moving the arm mechanism to bring the control point's posture closer to the working posture.

Description

Divisional Application Instructions

[0001] This invention is a divisional application of Chinese national patent application No. 202180019815.2, filed on February 15, 2021, entitled "Robot System, Parallel Linkage Mechanism, Control Method, Control Device, Program and Storage Medium". Technical Field

[0002] This invention relates to robot systems, parallel linkage mechanisms, control methods, control devices, programs, and storage media. Background Technology

[0003] Multi-jointed boom mechanisms are widely used in industry. For example, when performing tasks using end effectors mounted on boom mechanisms, there are situations where the posture of control points is adjusted via feedback control. During adjustment, if the posture of the control point becomes near a specific point, the movement of the boom mechanism becomes unstable. As a result, the boom mechanism or end effector may interfere with other components, or the operation may take longer than usual.

[0004] Existing technical documents Patent documents Patent Document 1: Japanese Patent Application Publication No. 2019-90727 Summary of the Invention

[0005] The problem that the invention aims to solve The purpose of this invention is to provide a robot system, control method, control device, program, and storage medium that can suppress unstable movements when the posture of the control point is adjusted through feedback control.

[0006] Another object of the present invention is to provide a parallel linkage mechanism suitable for use in robotic systems.

[0007] Methods used to solve problems The robot system of the relevant technical solution includes a multi-joint arm mechanism, a parallel linkage mechanism, an end effector, a detector, and a control device. The parallel linkage mechanism includes a fixed part mounted on the front end of the arm mechanism and a movable part mounted on the fixed part via multiple parallel links and movable relative to the fixed part. The end effector is mounted on the movable part. The detector is provided to detect the position or orientation of a control point. The control device controls the arm mechanism and the parallel linkage mechanism. The control device performs a first action of moving the arm mechanism and setting the posture of the control point to a predetermined first posture, and a second action, based on the detection results of the detector, moving the parallel linkage mechanism and setting the posture of the control point to a working posture for the end effector to perform operations. Between the first and second actions, the control device performs: a calculation process, based on the detection results of the detector, calculating the displacement of the posture of the control point up to the working posture; and a determination process, determining whether the displacement is within the movable range of the movable part. When the displacement exceeds the movable range, the control device moves the arm mechanism so that the posture of the control point is close to the working posture, and then performs the second action. Attached Figure Description

[0008] Figure 1 This is a three-dimensional view showing the robot system according to the implementation method.

[0009] Figure 2 This is a perspective view showing a parallel linkage mechanism according to an embodiment.

[0010] Figure 3 This is a schematic diagram illustrating the operation of a robot system according to an implementation method.

[0011] Figure 4 This is a schematic diagram representing a special point that serves as a control point.

[0012] Figure 5 This is a schematic diagram illustrating an example of the operation of a robot system according to an implementation method.

[0013] Figure 6 This is a schematic diagram illustrating another example of the operation of a robot system according to an implementation method.

[0014] Figure 7 This is a schematic diagram illustrating another example of the operation of a robot system according to an implementation method.

[0015] Figure 8 This is a flowchart illustrating the actions of a robot system according to an implementation method.

[0016] Figure 9This is a flowchart illustrating the actions of a robot system according to an implementation method.

[0017] Figure 10 This is a perspective view of the end effector of a robot system according to an embodiment.

[0018] Figure 11 It is a three-dimensional diagram showing the internal structure of the front end of the inspector.

[0019] Figure 12 This is a schematic diagram used to illustrate the inspection method performed by the inspector.

[0020] Figure 13 This is a flowchart illustrating the process of inspection performed by a robot system according to a relevant implementation.

[0021] Figure 14 This diagram illustrates the method for calculating tilt during inspection.

[0022] Figure 15 This is an example of an image obtained during the inspection.

[0023] Figure 16 This is an example of an image obtained during the inspection. Detailed Implementation

[0024] The following is a reference to the appendix. Figure 1 The various embodiments of the present invention will be described below.

[0025] The accompanying drawings are schematic or conceptual, and the relationship between the thickness and width of each part, the ratio of the size between parts, etc., may not necessarily be the same as in reality. Even when representing the same parts, there are cases where the dimensions or ratios between them are represented differently according to the drawings. In the specification and drawings of this application, the same reference numerals are given to the same elements as those already described, and detailed descriptions are omitted where appropriate.

[0026] Figure 1 This is a three-dimensional view showing the robot system according to the implementation method.

[0027] The robot system 1 described in the implementation method is as follows: Figure 1 As shown, it includes an arm mechanism 100, a parallel linkage mechanism 200, an end effector 300, a detector 400, and a control device 500.

[0028] The arm mechanism 100 includes multiple links 110 and multiple rotating shafts 120. One end of each link 110 is connected to the other by a rotating shaft 120. If a motor drives the rotating shaft 120, one link 110 rotates relative to another link 110.

[0029] A parallel linkage mechanism 200 is mounted on the front end of the arm mechanism 100. Specifically, the parallel linkage mechanism 200 is mounted on any part of one end of a plurality of links 110. The other end of the plurality of links 110 is connected to a base 130. The base 130 is fixed to a floor, wall, or other installation location.

[0030] The parallel linkage mechanism 200 includes a fixed part 210, a movable part 220, connecting rods 230, and multiple actuators 240. The fixed part 210 is mounted on the front end of the arm mechanism 100. The movable part 220 is mounted on the fixed part 210 via multiple connecting rods 230. The multiple connecting rods 230 are arranged in parallel between the fixed part 210 and the movable part 220. The multiple connecting rods 230 are respectively connected to the multiple actuators 240.

[0031] For example, multiple actuators 240 are motors and are mounted on the fixed part 210. If the multiple actuators 240 drive multiple links 230 respectively, their power is transmitted to the movable part 220, which moves relative to the fixed part 210.

[0032] The posture of the fixed part 210 corresponds to the posture of the front end of the arm mechanism 100 and is determined by the movement of the arm mechanism 100. Here, posture refers to position and orientation. The posture is determined by the position and angle (pitch, roll, yaw) of each of the three mutually orthogonal directions (X, Y, and Z directions). The posture of the movable part 220 is variable relative to the posture of the fixed part 210.

[0033] The arm mechanism 100 preferably has 4 or more degrees of freedom. For example, the arm mechanism 100 is a vertical multi-joint robot with 6 degrees of freedom. That is, the arm mechanism 100 can control the position of its front end in 3 directions and the angle of its front end around 3 directions.

[0034] Similarly, the parallel linkage mechanism 200 preferably has 4 or more degrees of freedom. For example, the parallel linkage mechanism 200 has 6 degrees of freedom. That is, the parallel linkage mechanism 200 can control the position of the movable part 220 in 3 directions and the angle of the movable part 220 around 3 directions.

[0035] The end effector 300 is mounted on the movable part 220. That is, the end effector 300 is mounted on the arm mechanism 100 via the parallel linkage mechanism 200. The posture of the end effector 300 is determined by the movement of the arm mechanism 100 and the movement of the parallel linkage mechanism 200.

[0036] The detector 400 detects the position or orientation of the control point. The control device 500 controls the arm mechanism 100 and the parallel linkage mechanism 200, adjusting the posture of the control point. The control point is the point whose position and orientation are controlled by the control device 500. The control point can be set, for example, to any point of the movable part 220. Alternatively, the control point can be set to any point of the end effector 300.

[0037] Detector 400 includes, for example, at least one of a range sensor, a light position sensor, and a camera. The position or orientation detected by detector 400 can be either absolute or relative. For example... Figure 1 As shown, detector 400 is mounted on movable part 220. End effector 300 and detector 400 are fixed relative to movable part 220. Therefore, the posture of detector 400 corresponds to the posture of control point. In this case, detector 400 detects the relative position or orientation of control point relative to the work object. Alternatively, detector 400 may be separately installed with arm mechanism 100 and parallel linkage mechanism 200. In this case, detector 400 detects the absolute position or orientation of control point in the space where arm mechanism 100 and parallel linkage mechanism 200 are installed.

[0038] The control device 500 sends drive signals to each motor of the arm mechanism 100. Each motor is driven according to the drive signals, controlling the rotation angle of each rotating shaft 120. This controls the posture of the front end of the arm mechanism 100. Similarly, the control device 500 sends drive signals to each actuator 240 of the parallel linkage mechanism 200. Each actuator 240 is driven according to the drive signals, controlling the rotation angle of the rotating shaft of each actuator 240. This controls the posture of the movable part 220 relative to the fixed part 210.

[0039] For example, when the control device 500 controls the posture of the control point using only the arm mechanism 100, it calculates the rotation angle of each rotation axis 120 through inverse kinematics calculation to make the posture of the control point the desired posture. When the control device 500 controls the posture of the control point using only the parallel linkage mechanism 200, it calculates the rotation angle of each actuator 240's rotation axis through inverse kinematics calculation to make the posture of the control point the desired posture.

[0040] For example, when robot system 1 is performing a task, control device 500 calculates the rotation angle of each rotation axis 120 using inverse kinematics to make the posture of the control point the desired posture as designed in advance. Control device 500 sets the rotation angle of each rotation axis 120 to the calculated value. When the actual position and orientation of the work object are as designed in advance, the task can be performed appropriately by setting the posture of the control point to the desired posture.

[0041] If the actual position and orientation of the workpiece deviate from the pre-designed values, the detector 400 detects the amount of position and orientation deviation. The control device 500 calculates the rotation angle of the rotation axis of each actuator 240 through inverse kinematics calculation to correct the deviation. The control device 500 sets the rotation angle of each actuator 240 to the calculated value. Thus, the posture of the control point is set to correspond to the actual position and orientation of the workpiece.

[0042] In the illustrated example, the arm mechanism 100 and the parallel linkage mechanism 200 are controlled by a single control device 500. Alternatively, the arm mechanism 100 and the parallel linkage mechanism 200 can be individually controlled by multiple control devices 500.

[0043] The movable part 220 has a smaller range of motion relative to the fixed part 210 than the range of motion of the front end of the arm mechanism 100 relative to the base 130. For example, by moving the arm mechanism 100, the control device 500 can adjust the general posture of the control point relative to the work object. By moving the parallel linkage mechanism 200, the control device 500 can adjust the fine posture of the control point relative to the work object.

[0044] The control device 500 can also control the posture of the control point based on the detection results obtained by the detector 400. For example, after setting the arm mechanism 100 to a predetermined posture, the control device 500 can also adjust the fine posture of the control point by moving the parallel linkage mechanism 200 based on the detection results obtained by the detector 400.

[0045] The control device 500 includes processing circuitry including a central processing unit (CPU). The control device 500 is connected to a storage device 510. The storage device 510 includes storage media such as Read Only Memory (ROM), Random Access Memory (RAM), Hard Disk Drive (HDD), and Solid State Drive (SSD). The control device 500 controls various parts of the robot system 1 by reading and executing programs stored in the storage device 510. The control device 500 can also store data obtained during the actions of the robot system 1 in the storage device 510.

[0046] Control device 500 Figure 1As shown, it can also be connected to either input device 520 or output device 530. Input device 520 is used when a user inputs data to control device 500 or storage device 510. Input device 520 includes at least one of a keyboard, mouse, microphone (voice input), and touchpad. Output device 530 outputs data from control device 500 or data stored in storage device 510 in a user-readable manner. Output device 530 includes at least one of a monitor, speaker, printer, and projector. Devices such as touch panels that have the functions of both input device 520 and output device 530 can also be used.

[0047] The control device 500 is connected to the arm mechanism 100 and the parallel linkage mechanism 200 via wired communication, wireless communication, or a network. The control device 500 may also include multiple control units. For example, it may include a control unit (robot controller) that controls the arm mechanism 100, another control unit (another robot controller) that controls the parallel linkage mechanism 200, and yet another control unit that transmits and receives data with these control units. These control units are connected via wired communication, wireless communication, or a network. Similarly, the control device 500 may also be connected to the storage device 510, the input device 520, and the output device 530 via wired communication, wireless communication, or a network. Alternatively, two or more of the control device 500, storage device 510, input device 520, and output device 530 may be configured as a single device.

[0048] Figure 2 This is a perspective view showing a parallel linkage mechanism according to an embodiment.

[0049] Reference Figure 2 An example of a parallel linkage mechanism 200 suitable for the robot system 1 of the relevant implementation will be described. Figure 2 The parallel linkage mechanism 200 shown includes a fixed part 210, a movable part 220, a connecting rod 230, an actuator 240, a first joint component 250, a second joint component 260, and a rotating arm 270.

[0050] For the sake of explanation, the direction from the fixed part 210 toward the movable part 220 is referred to as "up" (first direction), and the opposite direction is referred to as "down". These directions are based on the relative positional relationship between the fixed part 210 and the movable part 220 and are independent of the direction of gravity.

[0051] In the illustrated example, the fixed part 210 and the movable part 220 are flat plates. The fixed part 210 has a lower surface 210a mounted on the front end of the arm mechanism 100 and an upper surface 210b (first surface) opposite to the lower surface 210a. The actuator 240 is mounted on the upper surface 210b of the fixed part 210. In this example, the actuator 240 is a motor. The rotation axis 241 of the actuator 240 is arranged in a direction intersecting the vertical direction.

[0052] A portion (part 271) of a rotating arm 270 is fixed to a rotating shaft 241. The rotating arm 270 is driven by an actuator 240 around the rotating shaft 241. A first connector member 250 is mounted on another portion (part 272) of the rotating arm 270. The direction from part 271 to part 272 intersects the direction of the rotating shaft 241. If the rotating arm 270 rotates, the vertical distance between the movable part 220 and part 272 changes.

[0053] A bend 273 is provided between the first part 271 and the second part 272 of the rotating arm 270. The second part 272 is located on the movable part 220 side relative to the first part 271. In other words, the vertical position of the second part 272 is between the vertical position of the first part 271 and the vertical position of the movable part 220. The rotating arm 270 can be bent at the bend 273 either by bending or by bending smoothly.

[0054] One end of the connecting rod 230 is connected to the second portion 272 of the rotating arm 270 via a first connector component 250. The first connector component 250 is, for example, a universal joint with two degrees of freedom. The first connector component 250 includes connectors 251 and 252. Connector 251 is fixed to the second portion 272 of the rotating arm 270. Connector 252 is fixed to one end of the connecting rod 230.

[0055] The other end of the connecting rod 230 is connected to the movable part 220 via the second connector 260. The second connector 260 is mounted on the side 220a (third surface) of the movable part 220. The side 220a is inclined relative to the vertical direction and faces upward.

[0056] The second connector component 260 is, for example, a spherical connector with three degrees of freedom. The second connector component 260 includes a ball 261 and a seat 262. The axis of the seat 262 is fixed to the other end of the connecting rod 230 and contacts the spherical surface of the ball 261. The ball 261 is fixed to the side surface 220a. When the angle of the seat 262 changes, the ball 261 moves away from the side surface 220a to avoid interference between the seat 262 and the movable part 220.

[0057] An end effector 300 is mounted on the upper surface 220b (second surface) of the movable part 220. The side surface 220a is connected to the upper surface 220b. When the movable part 220 is in a reference posture, the upper surface 220b is, for example, parallel to the upper surface 210b. The reference posture of the movable part 220 refers to the state in which the movable part 220 adopts a pre-set specific posture within its range of motion. Figure 2 This indicates that the movable part 220 is in a reference posture. At this time, the movable part 220 is in the position closest to the fixed part 210.

[0058] The fixed part 210 has a hole 211 (first hole) for passing through the wiring of the multiple actuators 240 and the end effector 300. The hole 211 passes through the fixed part 210 in the vertical direction. The movable part 220 has a hole 221 (second hole) for passing through the wiring of the end effector 300. The hole 221 passes through the movable part 220 in the vertical direction.

[0059] For example, the wiring of the end effector 300 is led out toward the arm mechanism 100 through holes 211 and 221. For example, even if the wiring of the end effector 300 is installed on the front end of the arm mechanism 100 before the parallel linkage 200 is connected to the arm mechanism 100, the parallel linkage 200 can be connected to the arm mechanism 100 while the wiring of the end effector 300 is through holes 211 and 221.

[0060] The parallel linkage 200 can also be installed in a robot system that includes only the arm mechanism 100 and the end effector 300. In this case, after the end effector 300 is detached from the arm mechanism 100, the parallel linkage 200 and the end effector 300 can be easily installed to the front end of the arm mechanism 100 by leading the wiring connected to the end effector 300 through holes 211 and 221 to the front end of the parallel linkage 200.

[0061] The parallel linkage mechanism 200 includes a set of six links 230, actuators 240, a first joint component 250, a second joint component 260, and a rotating arm 270. For example, adjacent pairs of actuators 240a and 240b are arranged with their rotation axes parallel to each other. Similarly, adjacent pairs of actuators 240c and 240d are arranged with their rotation axes parallel to each other. The three pairs of actuators 240 are arranged at equal intervals around the hole 211.

[0062] A pair of rotary arms 270a and 270b are respectively connected to a pair of actuators 240a and 240b with their second portions 272 facing opposite directions. Similarly, a pair of rotary arms 270c and 270d are respectively connected to a pair of actuators 240c and 240d with their second portions 272 facing opposite directions.

[0063] Links 230 connected to one of the pairs of rotating arms 270 and link 230 connected to one of the other pairs of rotating arms 270 are connected to the same side 220a. For example, link 230b connected to rotating arm 270b and link 230c connected to rotating arm 270c are connected to the same side 220a. Links 230a connected to rotating arm 270a and link 230d connected to rotating arm 270d are each connected to another side 220a. The posture of the movable part 220 and the end effector 300 is controlled by independently controlling the rotation angle of the rotation shaft 241 of the six actuators 240.

[0064] The size of the upper surface 220b of the movable part 220 is smaller than the size of the upper surface 210b of the fixed part 210. For example, the size of the upper surface 220b in a direction intersecting the vertical direction is shorter than the size of the upper surface 210b in that direction.

[0065] With the movable part 220 in a reference posture, the connecting rod 230 is tilted toward the movable part 220 relative to the vertical direction. The axis of the connector 252 and the seat 262 is set along the connecting rod 230.

[0066] By providing the bend 273, the deflection angle of the first connector member 250 can be reduced when the movable part 220 is in a reference posture. By tilting the side surface 220a relative to the vertical direction, the deflection angle of the second connector member 260 can be reduced. For example, the angle of the bend 273 is set such that, when the movable part 220 is in a reference posture, the deflection angle of the first connector member 250 is 0 degrees. The tilt of the side surface 220a relative to the vertical direction is set such that, when the movable part 220 is in a reference posture, the deflection angle of the second connector member 260 is 0 degrees. Thus, while suppressing the enlargement of the parallel linkage mechanism 200, the range of motion of the movable part 220 relative to the fixed part 210 can be expanded.

[0067] Figure 3 (a) ~ Figure 3 (c) is a schematic diagram showing the action of the robot system according to the implementation method.

[0068] exist Figure 3 (a) ~ Figure 3In the example shown in (c), robot system 1 uses end effector 300 to perform a specified task for work object O.

[0069] First, such as Figure 3 As shown in (a), the work object O is conveyed to the grounded location of the arm mechanism 100. The work object O can be transported as follows: Figure 3 As shown in (a), it can be transported by the conveyor C, or by a person. The specific form of the conveyor C is arbitrary. Alternatively, the arm mechanism 100 can be mounted on an unmanned transport vehicle (AGV) or the like for movement. In this case, the orientation of the control point is arbitrary. In this example, the control point is set at the front end of the end effector 300.

[0070] The control device 500 performs the first action. In the first action, the control device 500 moves the arm mechanism 100, such as... Figure 3 As shown in (b), the posture of the control point is set to a predetermined first posture. Alternatively, a first action can be performed to bring the front end of the arm mechanism 100 into a predetermined posture. In the first action, if the posture of the front end of the arm mechanism 100 is determined when the parallel linkage mechanism 200 and the end effector 300 are not in motion, the posture of the control point is also determined. In this way, the posture of the control point can also be indirectly set to the first posture.

[0071] After the first action, detector 400 detects the position or orientation of the control point. For example, it detects the position or orientation of the control point when the front end of the arm mechanism 100 is in the first posture. Control device 500 executes the second action. In the second action, control device 500, as... Figure 3 The parallel linkage 200 is moved as shown in (c). At this time, the control device 500 adjusts the posture of the control point based on the detection results obtained by the detector 400. Thus, the posture of the control point is set to a posture suitable for the operation performed by the end effector 300.

[0072] Following the first and second actions, the end effector 300 performs a task towards the work object O. During the task, the control device 500 can also adjust the posture of the control point based on the detection results obtained from the detector 400. For example, the control device 500 adjusts the posture of the control point during the task by moving the parallel linkage mechanism 200. Tasks include, for example, painting, welding, inspection, fastening, assembly, and cutting. The specific form of the end effector 300 depends on the task being performed.

[0073] Explain the effects of the implementation method.

[0074] When the control device 500 moves the arm mechanism 100, for example, based on a movement command for a control point, the rotation angle or rotation speed of each rotation axis 120 of the arm mechanism 100 is determined by inverse kinematics calculation. On the other hand, there are controllable special points in the arm mechanism 100. Controllable special points refer to postures (positions and orientations) where the rotation angle of each rotation axis 120 cannot be determined by inverse kinematics calculation. At a special point, the rotation angle of each rotation axis 120 cannot be uniquely determined. Therefore, the posture of the arm mechanism 100 cannot be set to such a posture. Near a special point, the movement of the arm mechanism 100 may become unstable. Hereinafter, the special point and the posture near the special point will be collectively referred to as "near the special point."

[0075] Figure 4 (a) and Figure 4 (b) is a schematic diagram representing a special point of control point.

[0076] Figure 4 (a) indicates the state of the arm mechanism 100 when viewed from the side. Figure 4 (b) indicates the view of the arm mechanism 100 from above. Multiple rotation axes 120 extend from the base 130 toward the parallel linkage mechanism 200, including rotation axes 121-126. (e.g.) Figure 4 As shown in (a), when the rotation centers of rotation shaft 124 and rotation centers of rotation shaft 126 are aligned on the same straight line, the rotation of the parallel linkage mechanism 200 can be achieved by rotating either rotation shaft 124 or 126. Figure 4 As shown in (b), when the rotation centers of rotation shaft 121 and rotation centers of rotation shaft 126 are aligned on the same straight line, the rotation of the parallel linkage mechanism 200 can be achieved by rotating either rotation shaft 124 or 126. Figure 4 (a) and Figure 4 The posture shown in (b) does not uniquely determine the rotation angles of the rotation axes 121-126 through inverse kinematics calculations. Therefore, if the posture of the control point is near a specific point, the arm mechanism 100 may become uncontrollable.

[0077] For example, when the arm mechanism 100 is repeatedly made to perform the exact same movement through a teach-and-reproduce method, the arm mechanism 100 can be taught the action so that the posture of the control point does not become near a special point. However, when the posture of the control point is adjusted through feedback control, the control point may become the posture that was not taught. Therefore, in the adjustment of the posture of the control point, the posture of the control point may become near a special point.

[0078] In the robot system 1 of the relevant implementation, a parallel linkage mechanism 200 is provided at the front end of the arm mechanism 100. The parallel linkage mechanism 200 uniquely determines the drive amount of each actuator 240 based on the movement command for the control point through inverse kinematics calculation. Therefore, in the parallel linkage mechanism 200, there is no special point where the rotation angle cannot be determined, unlike the arm mechanism 100. For example, when the control device 500 adjusts the posture of the control point based on the detection results obtained by the detector 400, it moves the parallel linkage mechanism 200. Thus, the posture of the control point can be adjusted without moving the arm mechanism 100. Alternatively, the posture of the control point can be adjusted based on the detection results while the arm mechanism 100 performs only the pre-programmed action. Therefore, even when adjusting the posture of the end effector 300 through feedback control, it is also possible to avoid the posture of the front end of the arm mechanism 100 being near a special point.

[0079] Feedback control is particularly necessary when the robot system 1 performs highly precise tasks. For example, in painting, the posture of the end effector 300 may be adjusted to conform to the detailed shape of the surface of the workpiece, or the posture of the end effector 300 may be adjusted to correct minor positional deviations of the workpiece. In inspection, the posture of the end effector 300 may be adjusted based on information obtained from the workpiece during inspection in order to obtain more appropriate inspection results.

[0080] If the posture of the tip of the arm mechanism 100 is near a specific point during these operations, it will be difficult to complete the operation normally. Therefore, the robot system 1 of the embodiment is particularly preferred for situations where the posture of the end effector 300 needs to be adjusted based on the detection results obtained by the detector 400 during the operation.

[0081] In robot system 1, it is preferred to use Figure 2 The parallel linkage mechanism 200 is shown. According to this parallel linkage mechanism 200, the range of motion of the movable part 220 relative to the fixed part 210 can be expanded while suppressing excessive size. For example, interference between the parallel linkage mechanism 200 and the work object can be suppressed during operations performed by the end effector 300.

[0082] The following actions can also be performed in robot system 1.

[0083] Figure 5 (a) ~ Figure 5 (c) is a schematic diagram illustrating an example of the action of the robot system according to an embodiment.

[0084] Figure 5(a) indicates the state after the control device 500 performs the first action. At this time, the posture of the control point is set to the pre-programmed first posture.

[0085] After the first action, the control device 500 calculates the displacement required to set the control point's posture to the working posture for the end effector 300 to perform the operation, based on the detection results obtained by the detector 400. The displacement is represented by the movement in the X, Y, and Z directions, and the rotation angles of pitch, roll, and yaw. The control device 500 compares the displacement with the range of motion of the parallel linkage 200. As a specific example, the control device 500 calculates the displacement from the first posture to the working posture, and the control point compares the range of motion of the parallel linkage 200 in the first posture with the displacement.

[0086] When the displacement exceeds the movable range, the control device 500... Figure 5 As shown in (b), the pose of the control points is corrected to reduce the displacement. Then, as... Figure 5 As shown in (c), the control device 500 moves the parallel linkage mechanism 200 based on the detection result when the control point is in the corrected posture, and sets the posture of the control point as the working posture.

[0087] Based on this action, the control point can be set to the desired posture while suppressing as much of the unprogrammed movement performed by the arm mechanism 100 as possible.

[0088] Figure 6 of (a) Figure 6 of (b) Figure 7 (a) and Figure 7 (b) is a schematic diagram illustrating another example of the action of the robot system in relation to the implementation method.

[0089] Figure 6 (a) and Figure 5 Similarly, (a) indicates that the pose of the control point is set to the first pose. Then, the control device 500 can also... Figure 6 As shown in (b), regardless of the displacement from the first posture to the working posture, the arm mechanism 100 is moved based on the detection results obtained by the detector 400 to correct the posture of the control point.

[0090] During operations performed by the end effector 300, the parallel linkage 200 may sometimes need to be moved significantly based on detection results. In such cases, if the desired posture of the control point calculated based on the detection results is outside the range of motion of the parallel linkage 200, the arm mechanism 100 needs to be moved during the operation. In this situation, the posture adjustment performed by the parallel linkage 200 is stopped, and the posture of the control point is adjusted again using the parallel linkage 200 after the arm mechanism 100 has moved. To reduce the number of movements of the parallel linkage 200, the arm mechanism 100 can be moved before setting the control point to the working posture, thus setting the control point's posture to the corrected posture.

[0091] For example, in a correction action, the posture of the control point is corrected so that the posture of the control point relative to the work object O is in a predetermined first state. In the first state, the displacement required to set the posture of the control point to the work posture is smaller than the displacement from the first posture to the work posture. Preferably, the first state is determined such that after the posture of the control point is adjusted by the parallel linkage mechanism 200, the range of motion provided by the parallel linkage mechanism 200 also increases.

[0092] On the other hand, if the pose of the control points is set relative to the work object O, then as follows: Figure 6 As shown in (b), some of the rotation axes are arranged in a straight line, which may cause the posture of the front end of the arm mechanism 100 to be near a special point. Therefore, during the correction action, the control device 500 sets a correction posture to deviate the posture of the front end of the arm mechanism 100 from the vicinity of the special point.

[0093] Specifically, after the first action, the control device 500 calculates the posture of the control point relative to the work object O, which is in the first state. The control device 500 determines whether the posture of the front end of the arm mechanism 100 is near a special point under the calculated posture. If the posture of the front end is not near a special point, the control device 500 sets the posture of the control point to the first state. If the posture of the front end is near a special point, the control device 500 corrects the posture of the control point so that the posture of the control point relative to the work object O becomes the second state. Compared to the first state, the second state has a larger displacement up to the work posture.

[0094] Specifically, in the second state, the displacement required to set the control point's posture to the working posture is smaller than the displacement required to move from the first posture to the working posture. In the second state, the displacement required to set the control point's posture to the working posture is larger than the displacement required in the first state.

[0095] The result of performing corrections to deviate the posture of the front end of the arm mechanism 100 from the vicinity of a specific point is, for example, as Figure 7 As shown in (a), the posture of the control point relative to the work object O is set to the second state. Then, the control device 500... Figure 7 As shown in (b), the parallel linkage 200 is moved, and the posture of the control point is set to the working posture.

[0096] According to this action, while avoiding the posture of the front end of the arm mechanism 100 from becoming near a special point, during operation, the posture adjustment of the control point based on the detection result can be easily corresponded to by the parallel linkage mechanism 200 alone.

[0097] Figure 8 and Figure 9 This is a flowchart illustrating the actions of a robot system according to an implementation method.

[0098] Figure 8 express Figure 5 (a) ~ Figure 5 The action shown in (c) is as follows. First, the control device 500 executes the first action (first step) (step S1). In the first action, the arm mechanism 100 actuates, setting the posture of the control point to a predetermined first posture. The control device 500 executes a calculation process (calculation step) (step S2). In the calculation process, based on the detection results of the detector 400, the displacement of the posture of the control point up to the working posture is calculated. The control device 500 executes a determination process (determination step) (step S3). In the determination process, it is determined whether the displacement is within the movable range of the movable part 220.

[0099] When the displacement is within the movable range, the control device 500 executes the second action (second step) (step S4). In the second action, the parallel linkage mechanism 200 is activated based on the detection result of the detector 400, setting the posture of the control point to the working posture. When the displacement is outside the movable range, the control device 500 executes a correction action (correction step) (step S5). In the correction action, the arm mechanism 100 is activated, and the posture of the control point approaches the working posture. Then, the second action is executed.

[0100] The control device 500 performs the operation (step S6). The operation is performed using the end effector 300. During the operation, the posture of the control point is adjusted based on the detection results of the detector 400. The posture adjustment based on the detection results is performed by the parallel linkage mechanism 200.

[0101] Figure 9 express Figure 6 of (a) Figure 6 of (b) Figure 7 (a) and Figure 7The action shown in (b) is as follows. The control device 500 performs the first action (step S1) and performs calculation processing (step S2). In the calculation processing, based on the detection result of the detector 400, the posture of the control point relative to the work object O in the first state is calculated. The control device 500 performs determination processing (step S3). In the determination processing, it is determined whether the posture of the front end of the arm mechanism 100 in the first state is near a special point.

[0102] When the posture of the front end of the arm mechanism 100 is not near the special point in the first state, the control device 500 executes the first correction action (step S51). In the first correction action, the arm mechanism 100 moves to set the posture of the control point relative to the work object O to the first state. When the posture of the front end of the arm mechanism 100 is near the special point in the first state, the control device 500 executes the second correction action (step S52). In the second correction action, the arm mechanism 100 moves to set the posture of the control point relative to the work object O to the second state. After the first or second correction action, the control device 500 executes the second action (step S4) and performs the operation (step S6).

[0103] Figure 10 This is a perspective view of the end effector of a robot system according to an embodiment.

[0104] Reference Figure 10 An example of an end effector 300 used in robot system 1 of the relevant implementation will be described. Figure 10 In the example shown, an inspector 310 and a coating device 320 are provided as end effectors 300. In this example, the work object O is the component to be welded, and inspection is performed as part of the work. A control point is set at the front end of the inspector 310.

[0105] The inspector 310 includes multiple ultrasonic sensors for inspecting the weld. The coating apparatus 320 applies a coupling agent to the upper surface of the weld. The coupling agent is used to achieve acoustic matching of the ultrasonic waves between the inspector 310 and the object being inspected. The coupling agent can be either a liquid or a gel. In this example, a camera, serving as a detector 400, is positioned adjacent to the inspector 310 and the coating apparatus 320. The detector 400 photographs the welded component, acquiring an image. The detector 400 extracts the weld marks from the image, detecting the location of the weld.

[0106] Figure 11 It is a three-dimensional diagram showing the internal structure of the front end of the inspector.

[0107] Inside the front end of the inspector 310, there is a Figure 11The matrix sensor 311 is shown. The matrix sensor 311 includes multiple ultrasonic sensors 312. Each ultrasonic sensor 312 is, for example, a transducer. The multiple ultrasonic sensors 312 are arranged along two intersecting directions (X and Y directions). In this example, the X and Y directions are orthogonal. Furthermore, the X and Y directions in which the multiple ultrasonic sensors 312 are arranged may or may not correspond to the X and Y directions of a coordinate system representing the position of the control point.

[0108] The control device 500 moves the parallel linkage mechanism 200, causing the inspector 310 to move along the Z direction, which intersects a plane including the X and Y directions. The control device 500 brings the inspector 310 into contact with the object to be inspected, and inspects the welded part.

[0109] Figure 11 This indicates the condition of component 5 during inspection. Component 5 is manufactured by spot welding metal plate 51 (first component) and metal plate 52 (second component) at a welding section 53. In the welding section 53, a portion of metal plate 51 and a portion of metal plate 52 are fused together to form a solidified section 54. Each ultrasonic sensor 312 sends ultrasonic waves US toward component 5 coated with coupling agent 55 and receives reflected waves RW from component 5.

[0110] As a more specific example, such as Figure 11 As shown, one ultrasonic sensor 312 sends an ultrasonic wave US towards the weld 53. A portion of the ultrasonic wave US is reflected by the upper or lower surface of the component 5. Multiple ultrasonic sensors 312 respectively receive (detect) the reflected wave RW. By sequentially sending ultrasonic waves US through each ultrasonic sensor 312 and receiving each reflected wave RW by multiple ultrasonic sensors 312, a two-dimensional inspection is performed on the vicinity of the weld 53 of the component 5.

[0111] Figure 12 This is a schematic diagram used to illustrate the inspection method performed by the inspector.

[0112] like Figure 12 As shown in (a), a portion of the ultrasonic wave US is reflected by the upper surface 5a of the metal plate 51 or the upper surface 5b of the welded part 53. Another portion of the ultrasonic wave US is incident on the component 5 and reflected by the lower surface 5c of the metal plate 51 or the lower surface 5d of the welded part 53.

[0113] The upper surfaces 5a, 5b, 5c, and 5d are positioned differently in the Z-direction. That is, the distances between these surfaces and the ultrasonic sensor 312 in the Z-direction are different. If the ultrasonic sensor 312 receives reflected waves from these surfaces, it detects the peak values ​​of the reflected wave intensity. By calculating the time from transmitting the ultrasonic wave US to detecting each peak value, it is possible to investigate which surface reflected the ultrasonic wave US.

[0114] Figure 12 (b) and Figure 12 (c) is a graph illustrating the relationship between the time after the ultrasonic wave US is transmitted and the intensity of the reflected wave RW. Here, the intensity of the reflected wave RW is expressed in absolute value. Figure 12 The graph in (b) illustrates the reception results of the reflected wave RW from the upper surface 5a and lower surface 5c of the metal plate 51. Figure 12 The curve (c) represents the reception result of the reflected wave RW from the upper surface 5b and lower surface 5d of the welded part 53.

[0115] exist Figure 12 In the curve (b), the first peak Pe1 is based on the reflected wave RW from the upper surface 5a. The second peak Pe2 is based on the reflected wave RW from the lower surface 5c. The times at which peaks Pe1 and Pe2 are detected correspond to the positions of the upper surface 5a and lower surface 5c of the metal plate 51 in the Z direction, respectively. The time difference TD1 between the times at which peaks Pe1 and Pe2 are detected corresponds to the distance Di1 in the Z direction between the upper surface 5a and the lower surface 5c.

[0116] Similarly, in Figure 12 In the curve (c), the first peak Pe3 is based on the reflected wave RW from the upper surface 5b. The second peak Pe4 is based on the reflected wave RW from the lower surface 5d. The times when peaks Pe3 and Pe4 are detected correspond to the positions of the upper surface 5b and lower surface 5d of the welded part 53 in the Z direction, respectively. The time difference TD2 between the times when peaks Pe3 and Pe4 are detected corresponds to the distance Di2 in the Z direction between the upper surface 5b and the lower surface 5d.

[0117] The control device 500 checks whether points near the welded portion 53 have been welded based on the time difference between adjacent peak values. There are cases where the upper surface 5b and lower surface 5d of the welded portion 53 are inclined relative to the upper surface 5a of the metal plate 51. This is due to the welded portion 53 including the solidified portion 54 and deformation of its shape during the welding process. In this case, it is desirable to transmit ultrasonic waves US in an average vertical direction relative to the upper surface 5b or lower surface 5d. This allows for stronger reflection of the ultrasonic waves in the upper surface 5b and lower surface 5d, improving the accuracy of the inspection.

[0118] Figure 13 This is a flowchart illustrating the process of inspection performed by a robot system according to a relevant implementation.

[0119] First, the control device 500 performs the first action (step S1). The detector 400 photographs the component 5 and detects the position of the weld 53 based on the acquired image (step S11). The control device 500 then performs the second action (step S4). This adjusts the posture of the inspector 310 and the coating device 320. Alternatively, the operation can be performed between steps S11 and S4. Figure 8 or Figure 9 The calculation, judgment, and correction actions are shown.

[0120] The coating device 320 applies coupling agent 55 to the welded part 53 (step S12). The control device 500 moves the parallel linkage mechanism 200 so that the inspector 310 contacts the position where the welded part 53 is detected (step S13). With the inspector 310 in contact with the welded part 53, the control device 500 inspects the welded part 53 (step S14).

[0121] Specifically, multiple ultrasonic sensors 312 send ultrasonic waves US toward the component 5, including the welded part 53, and receive reflected waves RW. The inspector 310 sends the received results of the reflected waves to the control device 500. Based on the received results, the control device 500 calculates the tilt of the inspector 310 relative to the welded part 53. Based on the calculation results, the control device 500 moves the parallel linkage mechanism 200 to adjust the posture of the front end of the inspector 310, so as to reduce its tilt.

[0122] After the inspector 310's posture is adjusted, multiple ultrasonic sensors 312 re-emit ultrasonic waves US and receive reflected waves RW. Based on this reflection result, the control device 500 determines whether the welded part 53 has been properly welded. Thus, the inspection of the welded part 53 is completed. The control device 500 determines whether there are any uninspected welded parts 53 (step S15). If there are no uninspected welded parts 53, the operation ends. If there are uninspected welded parts 53, the control device 500 performs the first operation again for the uninspected welded parts 53.

[0123] The following is a specific example illustrating the calculation method for tilt.

[0124] Figure 14 This diagram illustrates the method for calculating tilt during inspection.

[0125] Figure 15 and Figure 16 This is an example of an image obtained during the inspection.

[0126] Figure 15 It is a three-dimensional volume data depicted based on the detection results of reflected waves. Figure 16 (a) represents Figure 15 The surface of the welded part 53 in the body data shown. Figure 16 (b) indicates Figure 15 The Y-Z section near weld 53 in the volume data shown. Figure 16 (c) represents Figure 15 The X-Z section near weld 53 in the volume data shown. Figure 16 (b) and Figure 16 In (c), the upper side is the surface of the welded part 53, and the lower side represents the data in the depth direction. The brighter parts are those with higher ultrasonic wave reflection intensity. Ultrasonic waves are strongly reflected by the bottom surface of the welded part 53, the surfaces between unjoined parts, etc.

[0127] The tilt of the inspector 310 corresponds to Figure 14 The angle shown is between the direction 53a perpendicular to the weld 53 and the direction 310a of the inspector 310. This angle is represented by the angle θx about the X direction and the angle θy about the Y direction. The direction 310a of the inspector 310 is perpendicular to the arrangement direction of the ultrasonic sensors 312.

[0128] Angle θx Figure 16 As shown in (b), the angle θy is calculated based on the detection results in the Y-Z section. Figure 16 As shown in (c), the calculation is based on the detection results in the X-Z section. For each section, the control device 500 calculates the average value of the three-dimensional brightness gradient as angles θx and θy. The control device 500 stores the calculated angles θx and θy as the tilt of the inspector 310 in the storage device 510.

[0129] This section describes an example of how the control device 500 controls the arm mechanism 100 and the parallel linkage mechanism 200 to perform inspection-related processes. It is not limited to this example; other control devices may be provided to control the arm mechanism 100 and the parallel linkage mechanism 200 and to perform inspection-related processes. Inspection-related processes may also be performed via a network by other control devices or processing devices.

[0130] The above describes an example of a robot system 1 including a vertically multi-jointed arm mechanism 100 with 6 degrees of freedom. It is not limited to this example; the arm mechanism 100 can have 4 or more degrees of freedom. With 4 or more degrees of freedom, after the approximate posture of the control point is adjusted by the arm mechanism 100, the finer posture of the control point can be adjusted using the parallel linkage mechanism 200. Alternatively, a horizontally multi-jointed arm mechanism 100 with 4 or more degrees of freedom can also be provided. By using the parallel linkage mechanism 200 to adjust the posture of the control point in both configurations, unstable movements can be suppressed even when adjusting the posture of the control point using feedback control.

[0131] The implementation method includes the following structure.

[0132] (Structure 1) A robot system includes: a multi-jointed arm mechanism; a parallel linkage mechanism including a fixed part mounted on the front end of the arm mechanism and a movable part mounted on the fixed part via a plurality of parallel links and movable relative to the fixed part; an end effector mounted on the movable part; a detector for detecting the positional or orientational relationship between the movable part and the work object; and a control device for controlling the arm mechanism and the parallel linkage mechanism; wherein, when the end effector performs an operation, the control device moves the parallel linkage mechanism based on the detection result obtained by the detector, thereby adjusting the posture of the end effector.

[0133] By using the robot system, robot system control method, or control device described above, and by adjusting the posture of the end effector 300 with the aid of feedback control, unstable movements can also be suppressed. The same effect can be achieved by using a program that executes the control method described above using the robot system's control device.

[0134] The processing of the various data described above can also be recorded as programs that can be executed by a computer on disks (floppy disks and hard disks, etc.), optical discs (CD-ROM, CD-R, CD-RW, DVD-ROM, DVD±R, DVD±RW, etc.), semiconductor memory, or other recording media.

[0135] For example, data recorded on a recording medium can be read by a computer (or an installed system). The recording format (storage format) on the recording medium is arbitrary. For example, a computer reads a program from the recording medium, and based on that program, causes the CPU to execute the instructions written in the program. In a computer, program retrieval (or reading) can also be done via a network.

[0136] The above describes several embodiments of the present invention, but these embodiments are merely illustrative and not intended to limit the scope of the invention. These new embodiments can be implemented in a wide variety of other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included within the scope or spirit of the invention, and are also included within the scope of the invention as described in the claims and its equivalents. The above-described embodiments can be combined with each other for implementation.

Claims

1. A robot system, characterized in that, have: Multi-jointed arm mechanism; A parallel linkage mechanism includes a movable part that is movable relative to the front end of the arm mechanism by means of a plurality of parallel links mounted at the front end of the arm mechanism, and the parallel linkage mechanism has more than 4 degrees of freedom relative to the front end of the arm mechanism. An end effector, mounted on the aforementioned movable part, has an inspector including an ultrasonic sensor; Detectors detect the position or orientation of control points; and The control device controls the aforementioned arm mechanism and the aforementioned parallel linkage mechanism to execute a first action and a second action. The first action is to move the aforementioned arm mechanism to set the posture of the aforementioned control point to a predetermined first posture. The second action is to move the aforementioned parallel linkage mechanism based on the detection result of the aforementioned detector after the aforementioned first action, and set the posture of the aforementioned control point to the action posture of the aforementioned end effector. Following the second action described above, the control device performs the following actions: Based on the received results of the reflected waves when the ultrasonic sensor sends ultrasonic waves to the work object, the tilt of the inspection device relative to the work object is calculated. The above-mentioned parallel linkage mechanism is activated to reduce the aforementioned tilt.

2. The robot system as described in claim 1, characterized in that, The above control device performs the following: The computational processing, based on the detection results of the aforementioned detectors, calculates the displacement of the posture at the aforementioned control point up to the aforementioned action posture; and The determination process involves determining whether the aforementioned displacement is within the movable range of the aforementioned movable part. In the above determination process, when the displacement exceeds the movable range, the control device moves the arm mechanism to make the posture of the control point close to the action posture, and then performs the second action.

3. The robot system as described in claim 1, characterized in that, The aforementioned control device performs the following actions: Between the first action and the second action described above, a correction action is performed to move the arm mechanism based on the detection result of the detector and set the posture of the control point to the correction posture. In the above-mentioned correction action, the above-mentioned correction posture is set so that the posture of the front end of the above-mentioned arm mechanism is deviated from the vicinity of the special point.

4. The robot system as described in claim 1, characterized in that, In the first action, the control device moves the arm mechanism to avoid a special point of the arm mechanism, and in the second action, moves the parallel linkage mechanism while maintaining the first posture that avoids the special point.

5. The robot system as described in claim 1, characterized in that, After the second action described above, the control device performs the action of moving the parallel linkage mechanism to bring the inspection device into contact with the object. The calculation of the tilt of the aforementioned inspector is performed after the aforementioned contact action.

6. The robot system as described in any one of claims 1 to 5, characterized in that, The aforementioned work involves multiple components and welded joints formed by the joining of these components. The aforementioned control device calculates the tilt of the aforementioned inspector relative to the aforementioned welded portion.

7. The robot system as described in claim 6, characterized in that, Multiple ultrasonic sensors are arranged along the first arrangement direction and the second arrangement direction intersecting the first arrangement direction. The aforementioned parallel linkage mechanism has 6 degrees of freedom relative to the aforementioned arm mechanism. The control device calculates the first angle around the second arrangement direction by calculating the gradient of the intensity of the reflected wave in a first cross section along the first arrangement direction and the intersection direction of the surface containing the first arrangement direction and the second arrangement direction. The second angle around the first arrangement direction is calculated by calculating the gradient of the intensity of the reflected wave in the second cross section along the second arrangement direction and the intersection direction. Using the first angle and the second angle mentioned above as the tilt, the parallel linkage mechanism is activated to reduce the tilt.

8. The robot system as described in any one of claims 1 to 5, characterized in that, The aforementioned parallel linkage mechanism also includes a fixing part installed at the aforementioned front end of the aforementioned arm mechanism. The movable part is mounted to the fixed part via the aforementioned plurality of parallel connecting rods, and is movable relative to the fixed part. The above-mentioned parallel linkage mechanism also includes: An actuator is mounted on the aforementioned fixed portion, and its rotation axis is arranged along a direction intersecting a first direction from the aforementioned fixed portion toward the aforementioned movable portion; The rotating arm, having a first part connected to the aforementioned rotating shaft, is rotated by the aforementioned actuator; and The connecting rod is connected to the second part of the aforementioned rotating arm via the first joint member, and to the aforementioned movable part via the second joint member. A bend is provided between the first part and the second part of the aforementioned rotating arm. The second part is located on the movable part side relative to the first part.

9. The robot system as described in claim 8, characterized in that, The aforementioned fixing part has a first surface for mounting the aforementioned actuator. The movable part has a second surface for mounting the end effector and a third surface that is inclined relative to the first direction and faces the first direction. The dimensions of the second surface mentioned above are smaller than the dimensions of the first surface mentioned above. The second connector component is installed on the third surface.

10. The robot system as described in claim 8, characterized in that, The aforementioned fixing part is provided with a first hole that penetrates the fixing part along the aforementioned first direction. The movable part is provided with a second hole that passes through the movable part along the first direction.

11. A control method for a robot system, the robot system comprising: Multi-jointed arm mechanism; The parallel linkage mechanism includes a fixed part installed at the front end of the arm mechanism and a movable part installed on the fixed part via a plurality of parallel links and movable relative to the fixed part, the parallel linkage mechanism having more than 4 degrees of freedom relative to the arm mechanism. An end effector, mounted on the aforementioned movable part, includes an inspector containing an ultrasonic sensor; and The detector detects the position or orientation of the control point. The control method is characterized by comprising: Step 1: Set the posture of the aforementioned control points to the prescribed first posture; and In the second step, following the first step, the parallel linkage mechanism is moved based on the detection results of the detector, and the posture of the control point is set as the action posture for the end effector to perform the action. In the above control method, after the second action, the tilt of the inspector relative to the work object is calculated based on the received result of the reflected wave when the ultrasonic sensor sends ultrasonic waves to the work object, and the parallel linkage mechanism is activated to reduce the tilt.

12. The control method as described in claim 11, characterized in that, It also has: The calculation steps involve calculating the displacement of the posture at the control point up to the aforementioned action posture, based on the detection results of the detector; and The determination step involves determining whether the aforementioned displacement amount is within the movable range of the aforementioned movable part. The above calculation steps and the above determination steps are performed between the above step 1 and the above step 2. In the above determination step, when the displacement exceeds the movable range, after moving the arm mechanism to make the posture of the control point close to the action posture, the second step is executed.

13. The control method as described in claim 11, characterized in that, It also includes a correction step that moves the arm mechanism based on the detection results of the detector and sets the posture of the control point as the correction posture. The above-mentioned correction steps are performed between step 1 and step 2. In the above correction step, the above correction posture is set so that the posture of the front end of the above arm mechanism is deviated from the vicinity of the special point.

14. The control method according to any one of claims 11 to 13, characterized in that, During the operation performed by the end effector, the parallel linkage mechanism is moved based on the detection results of the detector, and the posture of the control point is adjusted.

15. A control device for controlling a robot system, the robot system comprising: Multi-jointed arm mechanism; A parallel linkage mechanism includes a movable part that is movable relative to the front end of the arm mechanism by means of a plurality of parallel links mounted at the front end of the arm mechanism, and the parallel linkage mechanism has more than 4 degrees of freedom relative to the front end of the arm mechanism. An end effector, mounted on the aforementioned movable part, includes an inspector containing an ultrasonic sensor; and The detector detects the position or orientation of the control point. The characteristic is that the above-mentioned control device performs: The first action is to set the posture of the aforementioned control points to the prescribed first posture; and The second action, following the first action, involves moving the parallel linkage mechanism based on the detector's detection result, and setting the posture of the control point as the action posture for the end effector to perform the action. After the second action described above, the control device calculates the tilt of the inspector relative to the work object based on the received result of the reflected wave when the ultrasonic sensor sends ultrasonic waves to the work object, and causes the parallel linkage mechanism to operate so as to reduce the tilt.

16. The control device as claimed in claim 15, characterized in that, The aforementioned control device also performs: The computational processing, based on the detection results of the aforementioned detectors, calculates the displacement of the posture at the aforementioned control point up to the aforementioned action posture; and The determination process involves determining whether the aforementioned displacement is within the movable range of the aforementioned movable part. In the above determination process, when the displacement exceeds the movable range, after moving the arm mechanism to make the posture of the control point close to the action posture, the second action is performed.

17. The control device as claimed in claim 15, characterized in that, Between the first action and the second action described above, a correction action is performed to move the arm mechanism based on the detection result of the detector and set the posture of the control point to the correction posture. In the above-mentioned correction action, the above-mentioned correction posture is set so that the posture of the front end of the above-mentioned arm mechanism is deviated from the vicinity of the special point.

18. The control device as described in any one of claims 15 to 17, characterized in that, During the operation performed by the end effector, the parallel linkage mechanism is moved based on the detection results of the detector, and the posture of the control point is adjusted.

19. A program, characterized in that, The control device that controls the robot system performs the following processes. The aforementioned robot system includes: Multi-jointed arm mechanism; A parallel linkage mechanism includes a movable part that is movable relative to the front end of the arm mechanism by means of a plurality of parallel links mounted at the front end of the arm mechanism, and the parallel linkage mechanism has more than 4 degrees of freedom relative to the front end of the arm mechanism. An end effector, mounted on the aforementioned movable part, includes an inspector containing an ultrasonic sensor; and The detector detects the position or orientation of the control point. The above procedure causes the control device to perform the following processing: The first action is to set the posture of the aforementioned control points to the prescribed first posture; The second action is to move the parallel linkage mechanism based on the detection result of the detector, and set the posture of the control point to the action posture of the end effector. After the second action described above, the control device calculates the tilt of the inspector relative to the work object based on the received result of the reflected wave when the ultrasonic sensor sends ultrasonic waves to the work object, and causes the parallel linkage mechanism to operate so as to reduce the tilt.

20. The procedure as described in claim 19, characterized in that, The aforementioned control device also performs: The computational processing, based on the detection results of the aforementioned detectors, calculates the displacement of the posture at the aforementioned control point up to the aforementioned action posture; and The determination process involves determining whether the aforementioned displacement is within the movable range of the aforementioned movable part. In the above determination process, when the displacement exceeds the movable range, after moving the arm mechanism to make the posture of the control point close to the action posture, the control device executes the second action.

21. The procedure as described in claim 19, characterized in that, Between the first and second actions, the control device performs a correction action, moving the arm mechanism based on the detector's detection result and setting the posture of the control point to a corrected posture. In the above-mentioned correction action, the above-mentioned correction posture is set so that the posture of the front end of the above-mentioned arm mechanism is deviated from the vicinity of the special point.

22. The procedure as described in any one of claims 19 to 21, characterized in that, During the operation performed by the end effector, the control device moves the movable part based on the detection result of the detector, thereby adjusting the posture of the control point.

23. A storage medium, characterized in that, The program is stored in any one of claims 19 to 22.

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