Robot system, control method for robot system, moving trestle, control method for moving trestle, article manufacturing method, program, and recording medium

Abstract

To shorten a time to a work start after moving.SOLUTION: A robot system includes a robot (10A). The robot system has a plurality of legs (110 and 120) which can touch a floor or a ground surface, and a moving trestle (100) which has an installation part where the robot (10A) is installed, and is movable to the floor or the ground surface. At least one of the plurality of legs (110 and 120) has a holding power changing part for changing fixing holding force between the plurality of legs (110 and 120) and the floor or the ground surface according to the state of the robot (10A).SELECTED DRAWING: Figure 10

Description

[Technical field]

[0001] The present invention relates to a robot system, a control method for a robot system, a movable platform, a control method for a movable platform, a manufacturing method for an article, a program, and a recording medium. [Background technology]

[0002] For example, in factories that carry out small-volume production, if a robot device that performs production is installed on the floor, multiple robot devices are required on the production line, and the operating time of these robot devices is short. Therefore, it is desirable to make the robot device movable and perform work at various locations, thereby increasing the operating time and reducing the number of robot devices, thereby reducing costs. However, when a robot device is moved, there is a problem that the robot device cannot perform high-precision work unless it is stabilized at the destination where it is moved. Therefore, various structures have been proposed for stabilizing the stand on which the robot device is mounted for a movable robot device (see Patent Documents 1, 2, and 3).

[0003] That is, the above-mentioned Patent Document 1 proposes a robot having a base on which the robot body is mounted and an extendable adjuster arm equipped with casters. Also, the above-mentioned Patent Document 2 proposes a base that is fixed to a work desk fixed to the floor using a clamp. Also, the above-mentioned Patent Document 3 proposes a base that is fixed by providing an insertion hole in the floor and inserting a positioning pin into the insertion hole. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2022-91213 [Patent Document 2] JP 2013-166197 A [Patent Document 3] JP 2020-82233 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the above Patent Document 1, the adjuster is manually adjusted to fix the base, which takes time to fix, and the robot device is installed. In addition, in the above Patent Document 2, the base is manually fixed to the work desk with a clamp, which takes time to fix, and the robot device is installed. In addition, in the above Patent Document 3, the base is fixed by inserting a pin into an insertion hole, which takes time to align the base and the insertion hole with high precision, which takes time to install the robot device. In addition, in the above Patent Documents 1 to 3, the base is fixed firmly to the floor, but it cannot be fixed firmly enough to fix the robot body to the floor, and the operation of the robot arm generates vibration in the base. Therefore, in order to perform high-precision work with the robot device, it is necessary to spend time on teaching the work after installation.

[0006] Therefore, an object of the present invention is to provide a robot system, a control method for a robot system, a mobile stand, a control method for the mobile stand, a manufacturing method for an article, a program, and a recording medium that are capable of shortening the time until work can begin when the robot system is moved. [Means for solving the problem]

[0007] One aspect of the present invention is a robot system comprising a robot, a plurality of legs capable of contacting a floor or the ground, an installation section on which the robot is installed, and a mobile stand capable of moving relative to the floor or the ground, wherein at least one of the plurality of legs has a holding force change section that changes the fixed holding force between the plurality of legs and the floor or the ground depending on the state of the robot.

[0008] One aspect of the present invention is a control method for a robot system comprising a robot, a plurality of legs capable of contacting a floor or ground, an installation section on which the robot is installed, a mobile platform movable relative to the floor or ground, and a control section, wherein at least one of the plurality of legs has a holding force changing section that changes the fixed holding force between the plurality of legs and the floor or ground, wherein the control section is provided with a holding force changing step that controls the magnitude of the fixed holding force in the holding force changing section depending on the state of the robot.

[0009] One aspect of the present invention is a mobile platform on which a robot is mounted and which is movable relative to a floor or the ground, the mobile platform having a plurality of legs which can be in contact with the floor or the ground, at least one of the plurality of legs having a holding force change unit which changes the fixed holding force between the plurality of legs and the floor or the ground depending on the state of the robot.

[0010] One aspect of the present invention is a control method for a mobile platform which is controlled by a control unit and which has a plurality of legs which can be in contact with a floor or ground and an installation unit on which a robot is installed, and which is movable relative to the floor or ground, and at least one of the plurality of legs has a holding force changing unit which changes the fixed holding force between the plurality of legs and the floor or ground, wherein the control unit is further characterized by having a holding force changing step which controls the magnitude of the fixed holding force in the holding force changing unit depending on the state of the robot. Effect of the Invention

[0011] According to the present invention, it is possible to reduce the time until work can be started when movement has been performed. [Brief description of the drawings]

[0012] [Figure 1] FIG. 1 is a diagram showing a mobile robot system according to a first embodiment. [Diagram 2]FIG. 2 is a diagram showing a state in which the mobile robot system according to the first embodiment has been moved to a working position. [Diagram 3] FIG. 2 is a bottom perspective view showing the movable pedestal according to the first embodiment. [Figure 4] 1A is a diagram showing the arrangement of fixed legs and movable legs in a moving base according to the first embodiment, and FIG. 1B is a top view showing a robot system according to the first embodiment. [Diagram 5] FIG. 2 is a perspective view showing a movable leg according to the first embodiment. [Figure 6] FIG. 2 is a perspective view showing the casters and their lifting mechanism in the movable stand according to the first embodiment. [Figure 7] FIG. 2 is a diagram illustrating the movement of the moving platform according to the first embodiment. [Figure 8] 1A is a bottom view of the robot system according to the first embodiment with the robot arm positioned at the center of the movable pedestal, FIG. 1B is a bottom view of the robot system according to the first embodiment with the robot arm moved in the X1 direction from the center of the movable pedestal, and FIG. 1C is a bottom view of the robot system according to the first embodiment with the robot arm moved in the X2 direction from the center of the movable pedestal. [Figure 9] (a) is a diagram showing the arrangement positions of the fixed legs and movable legs as a first pattern. (b) is a diagram showing the arrangement positions of the fixed legs and movable legs as a second pattern. (c) is a diagram showing the arrangement positions of the fixed legs and movable legs as a third pattern. (d) is a diagram showing the arrangement positions of the fixed legs and movable legs as a fourth pattern. (e) is a diagram showing the arrangement positions of the fixed legs and movable legs as a fifth pattern. (f) is a diagram showing the arrangement positions of the fixed legs and movable legs as a sixth pattern. [Figure 10] 1A is a diagram showing the arrangement positions of the fixed leg, the movable leg, and the gyro sensor in the first embodiment, FIG. 1B is a block diagram showing the structure of the first movable leg and the second movable leg in the first embodiment, and FIG. 1C is a block diagram showing the control system of the movable leg in the first embodiment. [Figure 11] 4 is a flowchart showing attitude control according to the first embodiment. [Figure 12] 13A is a diagram showing the arrangement positions of a fixed leg, a movable leg, and a gyro sensor in the second embodiment, and FIG.13B is a block diagram showing a control system for the movable leg in the second embodiment. [Figure 13] 10 is a flowchart showing attitude control according to a second embodiment. [Figure 14] 13A is a diagram showing the arrangement positions of a fixed leg, a movable leg, and a gyro sensor in the third embodiment, and FIG.13B is a block diagram showing a control system for the movable leg in the third embodiment. [Figure 15] 13 is a flowchart showing attitude control according to the third embodiment. [Figure 16] 13A is a diagram showing the arrangement positions of a fixed leg, a movable leg, and a gyro sensor in a fourth embodiment, and FIG. 13B is a block diagram showing the structure of a first movable leg, a second movable leg, and a third movable leg in the fourth embodiment. [Figure 17] FIG. 13 is a block diagram showing a control system for a movable leg in the fourth embodiment. [Figure 18] 13 is a flowchart showing attitude control according to the fourth embodiment. [Figure 19] 13A is a diagram showing the arrangement positions of a fixed leg, a movable leg, and a gyro sensor in the fifth embodiment, and FIG.13B is a block diagram showing a control system for the movable leg in the fifth embodiment. [Figure 20] 13 is a flowchart showing an initial setting control and a correction control according to the fifth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] First Embodiment A first embodiment for carrying out the present invention will be described below with reference to FIGS. 1 to 11. FIG.

[0014] [Outline of the robot system] First, the schematic configuration of the mobile robot system according to the first embodiment will be described with reference to FIG. 1. FIG. 1 is a diagram showing the mobile robot system according to the first embodiment. In the robot system 1, the direction in which the tip of the robot arm 10A faces is the front, the X direction is the left-right direction, the Y direction is the front-rear direction perpendicular to the X direction, and the Z direction is the up-down direction perpendicular to the X and Y directions. These X, Y, and Z directions are the coordinate system of the robot system 1, that is, the directions in which the robot system 1 moves together with its movement. Therefore, if the floor 2 is a horizontal plane, the Z direction remains the up-down direction even when the robot system 1 moves. The floor 2 may be the ground.

[0015] As shown in Fig. 1, a mobile robot system 1 roughly includes a mobile platform 100 having casters 191 and the like, and a robot device 10 installed and mounted on the mobile platform 100. The robot device 10 includes a base 11 installed on an installation section 101 of the mobile platform 100, and a robot arm 10A serving as a robot main body (or simply a robot) supported and installed on the base 11. The robot arm 10A in this embodiment is, for example, a six-axis multi-joint manipulator. A robot hand 19 (see Fig. 2) serving as an end effector can be attached to a link 12 at the tip of the robot arm 10A.

[0016] The robot system 1 also includes a robot controller 200 that controls the robot device 10, a hand controller 210 that controls the robot hand 19, and a vision controller 220 that controls a camera (not shown) attached to the robot hand 19. These controllers are stored and mounted inside the movable base 100. The movable base 100 also includes a PLC, UPS, etc. (not shown).

[0017] The robot controller 200 is configured by a computer using a microprocessor element and the like, and can control each part of the robot device 10 and the mobile platform 100. The computer configuring the robot controller 200 is configured by, for example, a CPU 201 as a control unit, a ROM 202 that stores a program for controlling each part, a RAM 203, a communication interface (I / F in the figure) 204, and the like. Among these, the RAM 203 is used for temporary storage of data such as teaching points and control commands by operating a teaching pendant (not shown), for example. The programs for controlling each part can be installed in the ROM 202 from a recording medium, or can be read from the recording medium to the ROM 202 via the communication interface 204. The communication interface 204 can also be connected to another computer device (PC or server) capable of editing the robot program.

[0018] The CPU 201 receives teaching point data input, for example, via a teaching pendant or the like, from the communication interface 204. Then, the CPU 201 can generate a trajectory for each axis (each link) of the robot device 10 based on the input teaching point data, and transmit it as a control target value to the robot device 10 via the communication interface 204. This enables the robot device 10 to perform an operation on a workpiece, which is an object to be operated, by using the robot hand 19 attached to the tip of the robot arm 10A.

[0019] On the other hand, the movable platform 100 is configured to be movable to any location by rolling on the floor 2 using casters 191 that are configured to be able to rise and fall, as will be described in detail later. The movable platform 100 also has a frame section 100F (see FIG. 6) inside, and the installation section 101 for installing the base 11 is provided on the frame section 100F. Furthermore, a plurality of (three in the first embodiment) fixed legs 110 are fixed to the frame section 100F, and the length of these fixed legs 110 in the vertical direction relative to the frame section 100F is invariable. Furthermore, the movable platform 100 is provided with a plurality of (two in the first embodiment) movable legs 120 that are attached to the frame section 100F and whose length in the vertical direction relative to the frame section 100F is variable. As will be described in detail later, these fixed legs 110 and movable legs 120 are configured to be able to touch the floor 2 according to the rise and fall of the casters 191.

[0020] Also provided on the top of the movable platform 100 is a lift switch 301 that controls a lift mechanism 195, which will be described in detail later, to change the vertical height of the casters 191. Also provided on the top of the movable platform 100 is a handle 350 that an operator can grab to move the movable platform 100. Also provided on the top of the movable platform 100 is an emergency stop button 302 that stops the operation of the robot arm 10A in the event of an abnormality.

[0021] Furthermore, an area sensor 403 that recognizes the surrounding environment is provided on the upper part of the mobile platform 100. The area sensor 403 is connected to the robot controller 200, and when the CPU 201 determines from the detection of the area sensor 403 that the mobile platform 100 is approaching and about to collide with a surrounding object during movement, it differentially applies a brake (not shown) to avoid the collision of the mobile platform 100. Furthermore, when the area sensor 403 detects that there is a person near the robot system 1, the CPU 201 controls the robot arm 10A to lower the upper limit of the operating speed. In other words, when the robot arm 10A works alone, it operates at the maximum speed, and when working in close proximity to a person, it operates at a reduced speed for safety reasons.

[0022] [Robot system operation] Next, the work performed by the robot system 1 according to the first embodiment will be described with reference to Fig. 2 and Fig. 7. Fig. 2 is a diagram showing a state in which the mobile robot system according to the first embodiment has been moved to a work position. Fig. 7 is a diagram explaining the movement of the mobile platform according to the first embodiment.

[0023] 2 and 7, for example, a fixed base 400 is fixed to the floor 2, and the robot system 1 can move to the front of the fixed base 400 to perform an assembly operation as a first operation. As shown in Fig. 7, for example, a connector (not shown), a board W1 as a workpiece into which the connector is inserted and assembled, a robot hand 19-1 that performs the connector assembly operation, and the like are arranged on a workbench 401 of the fixed base 400. That is, the robot system 1 can perform the connector assembly operation using the robot device 10 in a state in which the movable base 100 has been moved to and positioned in front of the fixed base 400.

[0024] In the connector assembly work, first, the robot hand 19-1 placed on a hand exchange table (not shown) is attached to the link 12 (see FIG. 1) at the tip of the robot arm 10A. Next, the robot hand 19-1 is moved to grip the connector, and the robot hand 19-1 gripping the connector is moved above the board W1 fixed to the work table 401 by a fixing jig. Then, the gripped connector is inserted into the board W1 and assembled. These operations are repeated to complete the assembly work by assembling a plurality of connectors to the board W1, which means that an article is manufactured. Also, when the connector assembly work is completed, the robot hand 19-1 is returned to the hand exchange table and removed from the robot arm 10A, and the robot arm 10A is moved to the center of the moving stand 100 to prepare for the movement of the robot system 1.

[0025] The robot hand 19-1 is equipped with a camera (not shown), and the robot controller 200 performs alignment by visual servo control of the robot arm 10A using an image captured by the vision controller 220. That is, this visual servo control controls the position and posture of the robot arm 10A while grasping the positions of the robot hand 19-1, the connector, the board W1, etc. This makes it possible for the robot hand 19 to automatically align and perform the connector assembly work when the robot system 1 is moved, even if the positions of the movable base 100 (robot arm 10A) and the fixed base 400 are not aligned with high precision.

[0026] Furthermore, a fixed base 500 is fixed to, for example, the floor 2 at a location separate from the fixed base 400, and the robot system 1 can move to the front of the fixed base 500 to perform an assembly operation as a second operation. On a workbench 501 of the fixed base 500, a pin placement stand Pa2 on which a pin (not shown) as a component is placed, an assembly work W2 as a work to be assembled by inserting the pin into a hole (not shown), a robot hand 19-2 that performs the pin assembly operation, and the like are arranged. That is, the robot system 1 can perform the pin assembly operation by the robot device 10 in a state where the movable base 100 is moved to and positioned in front of the fixed base 500.

[0027] In the pin installation work, first, the robot hand 19-2 placed on a hand exchange table (not shown) is attached to the link 12 (see FIG. 1) at the tip of the robot arm 10A. Next, the robot hand 19-2 is moved to grip the pin from the pin placement table as a work supply unit, and the robot hand 19-2 gripping the pin is moved above the work W2 to be installed that is fixed to the work table 501 by a fixing jig. Then, the gripped pin is inserted into the hole of the work W2 to be installed and installed. These operations are repeated to complete the installation work by installing a plurality of pins in the work W2 to be installed, that is, an article is manufactured. Also, when the pin installation work is completed, the robot hand 19-2 is returned to the hand exchange table and removed from the robot arm 10A, and the robot arm 10A is moved to the center of the moving base 100 to prepare for the movement of the robot system 1.

[0028] Similarly, the robot hand 19-2 is also provided with a camera (not shown), and the robot controller 200 performs alignment by visual servo control of the robot arm 10A using an image captured by the vision controller 220. That is, by this visual servo control, the position and posture of the robot arm 10A are controlled while grasping the positions of the robot hand 19-2, the pin, the workpiece W2 to be assembled, etc. This makes it possible for the robot hand 19 to automatically align itself and perform the pin assembly work when the robot system 1 is moved, even if the positions of the movable base 100 (robot arm 10A) and the fixed base 400 are not aligned with high precision.

[0029] As described above, the robot system 1 can perform a plurality of different tasks by moving to each location. As shown in FIG. 7, when moving the robot system 1, the lifting mechanism 195, which will be described in detail later, lowers the casters 191 so that they protrude below the fixed legs 110 and the movable legs 120 (see FIG. 2) and touches the floor 2. This allows the worker to move the mobile platform 100 while operating the handle 350. Also, as shown in FIG. 2, for example, the mobile platform 100 is moved to the front of the fixed platform 400 where the task is to be performed, and positioned at that position. At this time, the lifting mechanism 195, which will be described later, raises the casters 191 so that they retract above the fixed legs 110 and the movable legs 120, thereby touching the fixed legs 110 and the movable legs 120 to the floor 2. This positions the mobile platform 100 on the floor 2 and fixes it relative to the fixed platform 400.

[0030] [Fixed legs, movable legs, casters configuration] Next, the configuration of the fixed legs 110 and the movable legs 120 of the movable pedestal 100 according to the first embodiment will be described with reference to Figs. 3, 4, and 5. Fig. 3 is a bottom perspective view of the movable pedestal according to the first embodiment. Fig. 4(a) is a diagram showing the arrangement positions of the fixed legs and the movable legs of the movable pedestal according to the first embodiment. Fig. 4(b) is a top view of the robot system according to the first embodiment. Fig. 5 is a perspective view of the movable legs according to the first embodiment. Fig. 6 is a perspective view of the casters and their lifting mechanism of the movable pedestal according to the first embodiment.

[0031] 3, four casters 191 that can be raised and lowered, three fixed legs 110 whose vertical height is fixed with respect to the frame section 100F, and two movable legs 120 whose vertical height is variable are arranged on the lower part of the movable platform 100. That is, in the first embodiment, three or more legs are arranged in total, that is, three fixed legs 110 and two movable legs 120.

[0032] As shown in FIG. 4(a), the three fixed legs 110 are arranged in the Y direction, which is the front-rear direction of the movable platform 100, with one at the center of one side and two at both ends of the other side. A figure 900 formed by connecting the fixed legs 110 with lines as vertices is formed of a triangle. As shown in FIG. 4(b), the robot arm 10A (installation unit 101 (see FIG. 1)) is arranged approximately at the center of the movable platform 100 in the front-rear and lateral directions, and the center of gravity G of the robot arm 10A is inside the figure 900 as shown in FIG. 4(a). The two movable legs 120 are arranged outside the figure 900, and when the center of gravity G moves outside the figure 900 with a change in the position and posture of the robot arm 10A as described in detail later, the movable legs 120 receive the load.

[0033] (Configuration of movable legs) Next, the detailed configuration of the movable leg 120 will be described. As shown in FIG. 5, the movable leg 120 is attached to a bracket 100B fixed to a frame portion 100F (see FIG. 3) provided inside the movable platform 100. The movable leg 120 is configured to include a guide 121 having an oil-free bushing (not shown) therein, a shaft 123, a brake unit 122, and an air suction portion 125 as a holding force change portion. The shaft 123 is supported by the oil-free bushing of the guide 121 so as to be movable in the axial direction (up and down direction). The brake unit 122 is configured, for example, by a linear clamper Z, and is configured to be able to clamp the shaft 123 by the pressure of air supplied from an air joint 122a. An air suction portion 125 that can be attached to the floor 2 and change the suction force is disposed at the lower portion of the shaft 123. The air suction portion 125 is configured to have a pressure control valve 126 connected from an air joint 125a to a regulator 800 (see FIG. 10) for adjustably controlling the pressure, and a suction cup 127 whose internal pressure is adjusted by the pressure control valve 126.

[0034] Here, the operation of adjusting the length of the movable leg 120 will be described. For example, after the fixed leg 110 touches the floor surface, the shaft 123 of the movable leg 120 falls due to its own weight and comes into contact with the floor surface of the floor 2. After the contact, the CPU 201 of the robot controller 200 supplies air to the air joint 122a of the brake unit 122 via an electromagnetic valve (not shown), and the shaft 123 is clamped (the length is fixed) by the brake unit 122. Note that the adjustment of the length of the movable leg 120 is not limited to the configuration using the shaft 123 and the brake unit 122, and may be a configuration using, for example, an air cylinder or a ball screw.

[0035] Next, the suction operation between the movable leg 120 and the floor 2 by the air suction unit 125 will be described. When the air suction unit 125 suctions the floor 2, pressure (negative pressure) is applied to the air joint 125a from a regulator 800 (see FIG. 10) via a pressure control valve 126, which is a proportional solenoid valve. That is, by adjusting and controlling the communication amount of the opening of the pressure control valve 126, the internal pressure of the suction cup 127 is changed, thereby variably adjusting the suction force (fixing and holding force) between the suction cup 127 and the floor 2. Note that the pressure control valve 126 is not limited to a proportional solenoid valve that performs proportional control (duty control), but may be an ON / OFF solenoid valve that performs PWM control.

[0036] As described above, the movable legs 120 can automatically adjust the length in the vertical direction. For example, in the mobile platform using casters and adjusters described in JP 2022-91213 A, the adjusters arranged near the four casters are adjusted by an operator at the installation site, so that adjustment time is required for installation of the mobile platform. In contrast, the mobile platform 100 according to this embodiment uses three fixed legs 110 and two movable legs 120 whose length changes automatically, so that the posture of the mobile platform 100 can be stabilized in a short time.

[0037] (Caster mechanism) Next, a description will be given of the caster mechanism 190 that raises and lowers the caster 191. As shown in Fig. 7, the caster mechanism 190 is provided, for example, at two locations on the front and rear sides of the movable platform 100, and is attached to brackets 100B at two locations fixed to a frame portion 100F provided inside the movable platform 100.

[0038] In detail, the caster mechanism 190 has a caster base 198 to which two casters 191 are attached, a guide portion 192 that supports the caster base 198 so as to be vertically movable, and a lifting mechanism 195 that raises and lowers the caster base 198 in the vertical direction. The guide portion 192 has bearing portions 194 attached to the brackets 100B, and a guide shaft 193 that is guided by the bearing portions 194 so as to be vertically movable. The caster base 198 is fixedly supported by the guide shaft 193.

[0039] On the other hand, the lifting mechanism 195 as a switching mechanism has a driving stage 199 supported by two brackets 100B so as to be movable in the horizontal direction. The lifting mechanism 195 also has a cam follower 197 fixedly supported by the driving stage 199, and a cam plate 196 in which the cam follower 197 is engaged with a guide groove 196a. The driving stage 199 is provided with a driving motor (not shown), and the driving motor is driven by operating the lifting switch 301 (see FIG. 1) to move the driving stage 199 in the horizontal direction. When the cam follower 197 moves in the horizontal direction together with the driving stage 199, the cam follower 197 presses the guide groove 196a, thereby moving and driving the cam plate 196 fixed to the caster base 198 in the vertical direction. As a result, the caster base 198 is raised and lowered in the vertical direction together with the two casters 191. Therefore, the lifting mechanism 195 is configured to be switchable between an advanced position in which the casters 191 are advanced below the fixed legs 110 and a retracted position in which the casters 191 are retracted above the fixed legs 110.

[0040] In this embodiment, the caster 191 is raised and lowered using the caster mechanism 190, but the present invention is not limited to this, and the caster base or the caster itself may be raised and lowered using another driving source such as an air cylinder.

[0041] (Movement of the mobile platform and contact with the floor) The mobile platform 100 configured as described above is movable by an operator by rolling on the floor 2 with the casters 191 touching the ground, as shown in Fig. 7. When the mobile platform 100 is to be installed at a work site at a destination, the casters 191 are first raised by the caster mechanism 190. Then, the mobile platform 100 is basically grounded on the floor 2 by the three fixed legs 110, and the presence of three fixed legs 110 determines a single ground plane for the mobile platform 100. In other words, if the surface of the floor 2 (i.e., the floor surface) is approximately flat, the posture of the mobile platform 100 is stabilized by installing the three fixed legs 110.

[0042] Here, if the floor surface is not flat but uneven, one of the movable legs 120 may touch the ground before any of the three fixed legs 110 touch the ground. In other words, by adjusting the length of the movable legs 120, which can be adjusted in length, it is possible to make contact with the floor surface at three or more points, including the fixed legs 110, and the posture of the mobile platform 100 can be stabilized.

[0043] Furthermore, if the floor surface is an inclined surface, even if all three fixed legs 110 are in contact with the ground, the direction of gravity of the moving platform 100 does not coincide with the axial direction of the fixed legs 110, and the posture of the moving platform 100 will not be stable. Therefore, by adjusting the length of the movable legs 120, which have an adjustable length (to conform to the inclined surface), the movable legs 120 and the fixed legs 110 can come into contact with the floor surface at three or more points, and the posture of the moving platform 100 can be stabilized.

[0044] [Movement of center of gravity by driving the robot arm and change of fixed holding force by movable legs] Next, the movement of the center of gravity caused by the change in position and posture caused by driving the robot arm 10A, and the change in the fixing holding force with the floor 2 by the movable leg 120 will be described with reference to Fig. 8. Fig. 8(a) is a bottom view showing the robot system in a state where the robot arm according to the first embodiment is positioned at the center of the movable pedestal. Fig. 8(b) is a bottom view showing the robot system in a state where the robot arm according to the first embodiment is moved in the X1 direction from the center of the movable pedestal. Fig. 8(c) is a bottom view showing the robot system in a state where the robot arm according to the first embodiment is moved in the X2 direction from the center of the movable pedestal.

[0045] As shown in Fig. 8(a), for example, when the robot system 1 is moved by the moving platform 100, the position and posture of the robot arm 10A are controlled to be in the initial position (home position). Therefore, immediately after the robot system 1 is moved and the casters 191 are raised to place the three fixed legs 110, the movable legs 120A and the movable legs 120B on the floor 2, the center of gravity G of the robot arm 10A is inside the figure 900 that connects the two fixed legs 110 with a line. Therefore, the robot system 1 is supported by the three fixed legs 110 and is unlikely to tip over. In this state, the movable legs 120A and 120B are subjected to a normal force roughly equivalent to the weight of the robot arm distributed among the five legs.

[0046] Next, as shown in FIG. 8(b), when the robot system 1 starts the above-mentioned work, the robot arm 10A is driven and controlled to change the position and posture of the robot arm 10A, and for example, the position of the center of gravity G moves from the center in the X1 direction to the outside of the figure 900. Then, since the center of gravity G is located outside the figure 900, there is a risk that the robot system 1 will tip over. However, when the center of gravity G moves in the X1 direction, a force β is applied downward to the movable leg 120B in addition to the above normal force (β: force applied to the movable leg 120B due to the shift in the center of gravity position, >0), and the fixing and holding force to the floor 2 increases. Therefore, it is possible to prevent the robot system 1 from tipping over. Furthermore, a force α is applied upward to the movable leg 120A in addition to the above normal force (α: force applied to the movable leg 120A due to the shift in the center of gravity position, <0), so that the movable leg 120A will float off the floor 2. However, by using the air suction portion 125 of the movable leg 120A to suction and fix the movable leg 120A to the floor 2, a fixing force is generated that resists the moment caused by the movement of the center of gravity G, making it possible to further prevent the leg from tipping over.

[0047] 8(c), the position and posture of robot arm 10A further change, and the position of center of gravity G moves from the center in the X2 direction to the outside of figure 900. In this case, suction by air suction part 125 of movable leg 120A is stopped or the suction force is reduced, and conversely, the suction force between movable leg 120B and floor 2 is increased by air suction part 125 of movable leg 120B. This generates a fixing force that resists the moment caused by the movement of the position of center of gravity G, making it possible to prevent the robot from falling over.

[0048] In this way, the magnitude of the suction force between the air suction portion 125 of the movable leg 120A and the air suction portion 125 of the movable leg 120B is switched in response to the change in the position and posture of the robot arm 10A and the movement of the center of gravity G so as to be swapped in the X direction, which is the horizontal direction. This not only prevents the robot system 1 from falling over, but also changes the fixing and holding force against the floor 2 by the suction of the movable legs 120A and 120B in accordance with the movement of the center of gravity G, making it possible to suppress vibrations of the robot system 1, particularly in the horizontal direction. In particular, when attempting to fix the robot system 1 by maximizing the fixing and holding force between the movable legs 120A and 120B, it is difficult to suppress vibrations even if the robot system 1 can be prevented from falling over. In this embodiment, the fixing and holding force between the movable legs 120A and 120B is changed in accordance with the movement of the center of gravity G, so that it is possible to suppress vibrations while reducing the energy required for generating the fixing and holding force to the minimum necessary compared to the case where the fixing and holding force is maximized.

[0049] In the first embodiment, the movable leg 120 is provided with the air suction portion 125, and the suction force (fixed holding force) to the floor 2 is changed by air. However, the present invention is not limited to this, and for example, if the floor 2 is a magnetic body, the suction force (fixed holding force) to the floor 2 may be changed by electromagnetic force or the like. Furthermore, the suction force (fixed holding force) is not limited to electromagnetic force, and any force that can change the suction force (fixed holding force) may be used.

[0050] [Variations in the arrangement of fixed and movable legs] Next, modified arrangement patterns of fixed legs and movable legs provided on the moving base 100 of the robot system 1 will be described with reference to Fig. 9. Fig. 9(a) is a diagram showing the arrangement positions of fixed legs and movable legs as a first pattern. Fig. 9(b) is a diagram showing the arrangement positions of fixed legs and movable legs as a second pattern. Fig. 9(c) is a diagram showing the arrangement positions of fixed legs and movable legs as a third pattern. Fig. 9(d) is a diagram showing the arrangement positions of fixed legs and movable legs as a fourth pattern. Fig. 9(e) is a diagram showing the arrangement positions of fixed legs and movable legs as a fifth pattern. Fig. 9(f) is a diagram showing the arrangement positions of fixed legs and movable legs as a sixth pattern.

[0051] FIG. 9(a) shows a movable platform 100-1 having an arrangement pattern of the fixed legs 110 and the movable legs 120 as a first pattern. This first pattern is the arrangement pattern described as the first embodiment. That is, the three fixed legs 110 are arranged in one side in the Y direction, which is the front-rear direction of the movable platform 100, at the center in the X direction, and two are arranged near both ends in the X direction on the other side in the Y direction. In addition, the two movable legs 120 are arranged near both ends in the X direction, sandwiching the fixed leg 110 on one side in the Y direction. Therefore, the two movable legs 120 are arranged outside a figure 900-1 that connects the three fixed legs 110 with a line. In such an arrangement pattern of the first pattern, the range of a figure 901-1 that forms the outer edge by the three fixed legs 110 and the two movable legs 120 is a range in which the robot system 1 can be prevented from falling over even if the center of gravity G moves. In addition, since the two movable legs 120 are arranged side by side in the X direction, the vibration in the X direction can be easily reduced by changing the fixing and holding force of the two movable legs 120 to the floor 2 in an interchangeable manner. In addition, the vibration in the Y direction and the vibration in the Z direction can be reduced by changing the fixing and holding force of the two movable legs 120 to the floor 2 in a synchronized manner. In addition, in the robot system 1 having this movable platform 100-1, it is preferable to arrange the robot system 1 so that the working position where the robot arm 10A works is on one side in the Y direction (the upper side in the figure). This makes it easy to obtain the effect of suppressing vibration in the X direction with respect to the movement of the robot arm 10A in the X direction.

[0052] FIG. 9(b) shows a movable platform 100-2 having an arrangement pattern of fixed legs 110 and movable legs 120 as a second pattern. This second pattern is an arrangement pattern in which one movable leg 120 is added to the first pattern. That is, the three fixed legs 110 are arranged such that one is arranged at the center in the X direction on one side in the Y direction, which is the front-rear direction of the movable platform 100, and two are arranged near both ends in the X direction on the other side in the Y direction. In addition, the three movable legs 120 are arranged such that two are arranged near both ends in the X direction on both sides of the fixed leg 110 on one side in the Y direction, and one is arranged near the center in the X direction between the two fixed legs 110 on the other side in the Y direction. Therefore, the three movable legs 120 are arranged outside the figure 900-2 in which the three fixed legs 110 are connected by lines. In such a second arrangement pattern, the range of the figure 901-2 formed by the three fixed legs 110 and the three movable legs 120 is wider than that of the figure 901-1, and the range in which the robot system 1 can be prevented from falling over even if the center of gravity G moves is wider. In addition, since the three movable legs 120 are arranged in a triangular shape in the X and Y directions, the arrangement is easy to reduce vibrations in the X and Y directions by changing the fixing and holding forces of the three movable legs 120 to the floor 2 in an interchangeable manner. In addition, the arrangement is also capable of reducing vibrations in the Z direction by changing the fixing and holding forces of the three movable legs 120 to the floor 2 in a synchronized manner. Note that in the robot system 1 having this movable platform 100-1, the effect of vibration suppression can be obtained regardless of the direction in which the work position where the robot arm 10A works is located.

[0053] In addition, in a configuration including three or more fixed legs 110 and two or more movable legs 120, such as the arrangement patterns of the fixed legs 110 and the movable legs 120 in the first and second patterns shown in Fig. 9(a) and Fig. 9(b), it is preferable to configure as follows. That is, the installation part (robot arm 10A) is arranged inside a figure 900 that connects three or more fixed legs 110 with lines as vertices, and two or more movable legs 120 are arranged outside the figure 900. This makes it possible to achieve a configuration that is likely to provide the effects of preventing tipping and suppressing vibration.

[0054] FIG. 9(c) shows a movable platform 100-3 having a third pattern of fixed legs 110 and movable legs 120. This third pattern is a pattern in which two fixed legs 110 and one movable leg 120 are arranged. That is, one movable leg 120 is arranged near the center in the X direction on one side in the Y direction, and two fixed legs 110 are arranged near both ends in the X direction on the other side in the Y direction. Therefore, a figure 900-3 in which one movable leg 120 and two fixed legs 110 are connected by a line becomes a figure whose outer edge is formed by one movable leg 120 and two fixed legs 110. The range of this figure 900-3 is a range in which the robot system 1 can be prevented from falling over even if the center of gravity G moves. In addition, since one movable leg 120 is arranged on one side in the Y direction, this arrangement makes it easy to reduce vibrations in the Y direction and the Z direction. In addition, in the robot system 1 having the movable platform 100-3, it is preferable to arrange the robot system 1 so that the working position of the robot arm 10A is on one side in the Y direction (upper side in the figure). This makes it easier to obtain the effect of suppressing vibration in the Y direction against the movement of the robot arm 10A in the Y direction.

[0055] FIG. 9(d) shows a movable platform 100-4 having a fourth pattern of fixed legs 110 and movable legs 120. This fourth pattern is a pattern in which one fixed leg 110 and two movable legs 120 are arranged. That is, one fixed leg 110 is arranged near the center in the X direction on one side in the Y direction, and two movable legs 120 are arranged near both ends in the X direction on the other side in the Y direction. Therefore, a figure 900-4 obtained by connecting the two movable legs 120 and one fixed leg 110 with a line becomes a figure whose outer edge is formed by the two movable legs 120 and one fixed leg 110. The range of this figure 900-4 is a range in which the robot system 1 can be prevented from falling over even if the center of gravity G moves. In addition, since the two movable legs 120 are disposed on the other side in the Y direction, the vibration in the X direction can be easily reduced by changing the fixing and holding force of the two movable legs 120 to the floor 2 in an interchangeable manner. In addition, the vibration in the Y direction and the Z direction can be reduced by changing the fixing and holding force of the two movable legs 120 to the floor 2 in a synchronized manner. In the robot system 1 having this movable platform 100-4, it is preferable to dispose the robot system 1 so that the working position where the robot arm 10A works is on the other side in the Y direction (the lower side in the figure). This makes it easier to obtain the effect of suppressing vibration in the X direction with respect to the movement of the robot arm 10A in the X direction.

[0056] FIG. 9(e) shows a movable platform 100-5 having a fifth pattern of fixed legs 110 and movable legs 120. This fifth pattern is a pattern in which two fixed legs 110 and two movable legs 120 are arranged. That is, the two movable legs 120 are arranged near both ends in the X direction on one side in the Y direction, and the two fixed legs 110 are arranged near both ends in the X direction on the other side in the Y direction. Therefore, a figure 900-5 obtained by connecting the two movable legs 120 and the two fixed legs 110 with lines is a figure whose outer edge is formed by the two movable legs 120 and the two fixed legs 110. The range of this figure 900-5 is a range in which the robot system 1 can be prevented from falling over even if the center of gravity G moves. In addition, since the two movable legs 120 are arranged on one side in the Y direction, the vibration in the X direction can be easily reduced by changing the fixing and holding force of the two movable legs 120 to the floor 2 in an interchangeable manner. In addition, the vibration in the Y direction and the Z direction can be reduced by changing the fixing and holding force of the two movable legs 120 to the floor 2 in a synchronized manner. In the robot system 1 having this movable platform 100-5, it is preferable to arrange the robot system 1 so that the working position where the robot arm 10A works is on one side in the Y direction (upper side in the figure). This makes it easier to obtain the effect of suppressing vibration in the X direction with respect to the movement of the robot arm 10A in the X direction.

[0057] FIG. 9(f) shows a movable platform 100-6 having an arrangement pattern of the fixed legs 110 and the movable legs 120 as a sixth pattern. This sixth pattern is an arrangement pattern in which two fixed legs 110 and two movable legs 120 are arranged. That is, the two movable legs 120 are arranged near the center in the X direction on one side and the other side in the Y direction, and the two fixed legs 110 are arranged near both ends in the X direction near the center in the Y direction. Therefore, a figure 900-6 obtained by connecting the two movable legs 120 and the two fixed legs 110 with lines becomes a figure whose outer edge is formed by the two movable legs 120 and the two fixed legs 110. The range of this figure 900-6 is a range in which the robot system 1 can be prevented from falling over even if the center of gravity G moves. In addition, since the two movable legs 120 are arranged on one side and the other side in the Y direction, the fixing and holding force of the two movable legs 120 to the floor 2 can be changed in an interchangeable manner, which makes it easy to reduce vibration in the Y direction. In addition, the fixing and holding force of the two movable legs 120 to the floor 2 can be changed in a synchronized manner, which makes it possible to reduce vibration in the Z direction. In addition, in a robot system 1 having this movable platform 100-6, it is preferable to arrange the robot system 1 so that the work position where the robot arm 10A works is located on either side in the X direction (either the left or right in the figure). This makes it easy to obtain the effect of suppressing vibration in the Y direction with respect to the movement of the robot arm 10A in the Y direction.

[0058] [Attitude control according to the first embodiment] Next, attitude control for controlling the attitude of the mobile platform 100 according to the first embodiment will be described with reference to Figs. 10 and 11. Fig. 10(a) is a diagram showing the arrangement positions of the fixed leg, the movable leg, and the gyro sensor in the first embodiment. Fig. 10(b) is a block diagram showing the structure of the first movable leg and the second movable leg in the first embodiment. Fig. 10(c) is a block diagram showing the control system of the movable legs in the first embodiment. Fig. 11 is a flowchart showing attitude control according to the first embodiment.

[0059] (Control configuration of the moving platform) First, the configuration of the mobile platform 100 for performing posture control according to the first embodiment and the first and second movable legs 120A and 120B provided thereon will be described. As shown in Fig. 10(a), the mobile platform 100-1 (hereinafter simply referred to as "mobile platform 100") is configured with two movable legs 120 and three fixed legs arranged in the above-mentioned first arrangement pattern. Note that the two movable legs 120 are referred to as the first movable leg 120A and the second movable leg 120B to distinguish between them.

[0060] A first gyro sensor 600A and a second gyro sensor 600B are arranged on the upper part of the moving platform 100 as detectors for detecting changes in the state of the moving platform 100, which change according to the position and posture of the robot arm. In detail, the first gyro sensor 600A is arranged near the first movable leg 120A when viewed from the top-bottom direction, and the second gyro sensor 600B is arranged near the second movable leg 120B when viewed from the top-bottom direction. The first gyro sensor 600A and the second gyro sensor 600B detect the angular velocity caused by the tilt due to vibrations occurring in the moving platform 100, and output it to the robot controller 200.

[0061] As shown in Fig. 10(b), the first movable leg 120A has a first pressure control valve 126A as the above-mentioned pressure control valve, and a first suction cup 127A whose air pressure is adjusted by the first pressure control valve 126A (see Fig. 5). The first pressure control valve 126A is also connected to a first regulator 800A, which is a pressure regulator disposed inside the movable platform 100, via an air joint 125a (see Fig. 5). That is, the first regulator 800A generates negative pressure, and the first pressure control valve 126A adjusts the pressure, thereby adjusting the pressure of the air inside the first suction cup 127A, and the suction force between the first movable leg 120A and the floor 2, that is, the fixing and holding force is changed.

[0062] Similarly, the second movable leg 120B also has a second pressure control valve 126B and a second suction cup 127B whose air pressure is adjusted by the second pressure control valve 126B, and the second pressure control valve 126B is connected to a second regulator 800B. That is, a negative pressure is generated by the second regulator 800B, and the second pressure control valve 126B adjusts the pressure of the air inside the second suction cup 127B, and the suction force between the second movable leg 120B and the floor 2 is adjusted, that is, the fixing and holding force is changed.

[0063] 10(c), the first gyro sensor 600A and the second gyro sensor 600B are connected to be able to output the detected angular velocities to the CPU 201 of the robot controller 200. The CPU 201 is also connected to be able to output commands to adjust the pressures to the first pressure control valve 126A of the first movable leg 120A and the second pressure control valve 126B of the second movable leg 120B.

[0064] (Attitude control) Next, the posture control according to the first embodiment will be described. As described above, when the casters 191 are raised and the fixed legs 110 and the movable legs 120 are simply grounded on the floor 2, the robot system 1 is fixed in the horizontal direction only by friction between the floor 2 and each leg due to its weight. In addition, only the weight of the robot system 1 is applied to the floor 2 from each leg in the vertical direction (gravity direction). If the robot arm 10A, which weighs several tens of kilograms, were to operate in this state, there is a risk that the floor 2 and each leg will float and separate due to the movement of the center of gravity G or inertia. Therefore, the posture control according to the first embodiment is executed as follows.

[0065] As shown in FIG. 11, when the CPU 201 starts this posture control, it first calibrates the first and second gyro sensors 600A, 600B (S101). That is, in a state where the robot arm 10A is in the initial position, the tilt of the moving platform 100 is set to the initial position, and initial settings are performed. Next, the first and second pressure control valves 126A, 126B are set to a non-pressurized state (S102), that is, initial settings are performed for the first and second pressure control valves 126A, 126B. Then, it waits until it is determined that posture control should start (N in S103), and when it is determined that posture control should start based on, for example, the start of driving of the robot arm 10A, etc. (Y in S103), it proceeds to step S104.

[0066] When the CPU 201 starts the actual operation of attitude control, it first controls the settings of the first and second pressure control valves 126A, 126B to a low pressure state (S104), that is, starts the suction of the first and second suction cups 127A, 127B. Next, it reads the values ​​detected by the first and second gyro sensors 600A, 600B (S105) and calculates the tilt (attitude) of the movable base 100. Then, from the calculated attitude, the CPU 201 calculates the height of the first movable leg 120A side and the height of the second movable leg 120B side in the X direction of the movable base 100.

[0067] Next, the CPU 201 judges whether the first movable leg 120A side is lower or not based on the detection of the first and second gyro sensors 600A, 600B in the moving platform 100 (S106). If the first movable leg 120A side is not lower (N in S106), it then judges whether the second movable leg 120B side is lower or not (S108). Here, if the second movable leg 120B side is not lower either (N in S108), that is, the moving platform 100 is not tilted, so it proceeds to step S110. Then, it judges whether or not to end the posture control (S110), that is, it judges whether or not the driving (work) of the robot arm 10A is completed, and if the robot arm 10A is being driven, it judges to continue the posture control (N in S110), and returns to step S105.

[0068] Here, for example, when the robot arm 10A moves its tip toward the first movable leg 120A in the X direction to perform a task (see, for example, FIG. 8(c)), the side of the first movable leg 120A in the movable platform 100 becomes lower. Then, the CPU 201 determines that the side of the first movable leg 120A in the movable platform 100 becomes lower based on the respective velocities of the first and second gyro sensors 600A and 600B (Y in S106). In this case, the CPU 201 issues a command to the second pressure control valve 126B to increase (up) the suction force of the second suction cup 127B, and issues a command to the first pressure control valve 126A to decrease (down) the suction force of the first suction cup 127A (S107) (holding force changing process). In other words, the movable platform 100 detects that the position and posture of the robot arm 10A have changed and the center of gravity has moved toward the side of the first movable leg 120A. Then, by increasing the adhesive force (fixing and holding force) of the second movable leg 120B to the floor 2 on the other hand and decreasing the adhesive force (fixing and holding force) of the first movable leg 120A to the floor 2, the tilt of the moving base 100 is suppressed. This prevents the robot system 1 from falling over.

[0069] Also, for example, when the robot arm 10A moves its tip toward the second movable leg 120B in the X direction to perform a task (see, for example, FIG. 8(b)), the side of the second movable leg 120B in the movable platform 100 becomes lower. Then, the CPU 201 determines that the side of the second movable leg 120B in the movable platform 100 becomes lower based on the respective velocities of the first and second gyro sensors 600A and 600B (N in S106, Y in S108). In this case, the CPU 201 issues a command to the first pressure control valve 126A to increase (up) the suction force of the first suction cup 127A, and issues a command to the second pressure control valve 126B to decrease (down) the suction force of the second suction cup 127B (S109) (holding force changing process). In other words, the movable platform 100 detects that the position and posture of the robot arm 10A have changed and the center of gravity has moved toward the side of the second movable leg 120B. On the other hand, the adhesive force (fixing and holding force) of the first movable leg 120A to the floor 2 is increased, and the adhesive force (fixing and holding force) of the second movable leg 120B to the floor 2 is decreased, thereby suppressing the tilt of the moving base 100. This prevents the robot system 1 from falling over.

[0070] In this way, each time a tilt of the movable pedestal 100 is detected, the adhesive force (fixed holding force) of the first and second movable legs 120A, 120B to the floor 2 is controlled to suppress the tilt, and the tilt of the movable pedestal 100 is repeatedly suppressed. As a result, the adhesive force (fixed holding force) of the first and second movable legs 120A, 120B to the floor 2 is generated to suppress vibrations of the movable pedestal 100 caused by the movement of the robot arm 10A. Therefore, vibrations of the movable pedestal 100, particularly in the X direction, can be suppressed.

[0071] After that, when it is determined that the driving (work) of the robot arm 10A is completed, it is determined to end the posture control (Y in S110), and thus the posture control according to this embodiment is ended.

[0072] [Summary of the first embodiment] As described above, in the robot system 1 according to the first embodiment, when the robot system 1 (movable platform 100) is moved, the robot system 1 can be installed by simply raising the casters 191 and grounding the fixed legs 110 and the movable legs 120 on the floor 2. That is, since the movable legs 120 are provided with the air suction parts 125 capable of changing the fixing force with the floor 2, the robot system 1 can be prevented from falling over and vibration can be suppressed by the operation of the robot arm 10A. Therefore, the robot system 1 (particularly the robot arm 10A) can be stabilized at the installation location, and it is not necessary to fix it firmly to the floor 2. That is, if the movable legs and the fixed legs are fastened to the floor 2 by mechanical parts such as anchors, the fixing force becomes strong, but since the fixing force cannot be changed, it is not particularly effective in suppressing vibration. Furthermore, the fastening work by mechanical parts such as anchors takes time as an installation work at the destination of the robot system 1. Therefore, in this embodiment, when the robot system 1 (mobile platform 100) is moved, it can be easily set up at the installation site, and the time until the start of work can be shortened. Also, since the vibration of the mobile platform 100 can be suppressed in this way, the occurrence of assembly defects in parts assembled by the work of the robot system 1 can be reduced.

[0073] Furthermore, in the present robot system 1, when the casters 191 are raised to place multiple legs on the ground, the three fixed legs 110 are first made to conform to the floor 2, and then the two movable legs 120 are made to conform to the floor 2. Therefore, even if the surface of the floor 2 is uneven, for example, the multiple legs can be made to conform to the floor 2 and placed on the ground, and the mobile platform 100 can be stably installed.

[0074] In addition, in the present robot system 1, the two movable legs 120 are arranged outside the figure 900 formed by the lines connecting the three fixed legs 110, so that the range in which the movable legs 120 support the center of gravity G when the center of gravity G moves can be increased. This makes it possible to prevent the robot system 1 from falling over, and also to suppress the tilt of the mobile platform 100. Furthermore, these two movable legs 120 are provided with air suction parts 125, so that the suction force (fixing and holding force) with the floor 2 can be changed. Then, by performing posture control that controls the magnitude of the fixing and holding force of the air suction parts 125 according to the detection results of the first and second gyro sensors 600A and 600B, the posture of the mobile platform 100 can be stabilized, and vibration can also be suppressed.

[0075] The floor 2 on which the robot system 1 is installed may itself vibrate due to other machine tools or robot systems. For example, if the vibration caused by the operation of the robot arm 10A is about 1 Hz to 10 Hz, the floor 2 will vibrate finely at 10 Hz or more. In this embodiment, the first and second gyro sensors 600A and 600B can detect such vibration of the floor 2 through the fixed leg 110 and the movable leg 120. Therefore, by performing the above-mentioned posture control, the vibration of the floor 2 transmitted to the robot arm 10A can also be reduced. A vibration isolation mechanism, a vibration removal mechanism, or a vibration damping mechanism may be provided between the installation part of the moving platform 100 and the robot arm 10A to make it difficult for the vibration of the floor 2 to be transmitted to the robot arm 10A. As such a vibration isolation mechanism, a vibration removal mechanism, or a vibration damping mechanism, for example, a mechanism in which a gel-like vibration-proof sheet or the like is interposed may be considered.

[0076] <Second embodiment> Next, a second embodiment, which is a partial modification of the first embodiment, will be described with reference to Figs. 12 and 13. Fig. 12(a) is a diagram showing the arrangement positions of the fixed leg, the movable leg, and the gyro sensor in the second embodiment. Fig. 12(b) is a block diagram showing a control system for the movable leg in the second embodiment. Fig. 13 is a flowchart showing attitude control according to the second embodiment.

[0077] In this second embodiment, a solenoid is provided as a magnetic attraction unit instead of the air attraction unit 125 of the first embodiment, and the magnetic force generated by the solenoid is used to change the magnetic force that magnetically attracts the movable leg 120 to the floor 2, thereby changing the fixing and holding force of the movable leg 120. Note that this second embodiment is based on the premise that the floor 2 is a magnetic body, and that the floor 2 and the movable leg 120 are magnetically attracted to each other by magnetic force. The control configuration and attitude control according to this second embodiment will be described below.

[0078] (Control configuration of the moving platform) First, the configuration of the mobile pedestal 100 for performing posture control according to the second embodiment and the first and second movable legs 120A and 120B provided thereon will be described. As shown in Fig. 12(a), the mobile pedestal 100-1 (hereinafter simply referred to as "mobile pedestal 100") is configured with two movable legs 120 and three fixed legs arranged in the above-mentioned first arrangement pattern, similar to the first embodiment. Note that the two movable legs 120 are referred to as the first movable leg 120A and the second movable leg 120B to distinguish them.

[0079] As in the first embodiment, a first gyro sensor 600A and a second gyro sensor 600B are disposed on the upper part of the moving platform 100. In detail, the first gyro sensor 600A is disposed near the first movable leg 120A when viewed from the top-bottom direction, and the second gyro sensor 600B is disposed near the second movable leg 120B when viewed from the top-bottom direction. The first gyro sensor 600A and the second gyro sensor 600B detect angular velocity caused by tilt due to vibrations occurring in the moving platform 100, and output the angular velocity to the robot controller 200.

[0080] As shown in FIG. 12(b), the first movable leg 120A is provided with a first movable leg solenoid 1126A having a coil (not shown) that generates a magnetic force as a magnetic attraction part or a holding force change part. Similarly, the second movable leg 120B is provided with a second movable leg solenoid 1126B having a coil (not shown) that generates a magnetic force as a magnetic attraction part or a holding force change part. In addition, the mobile platform 100 is provided with a first solenoid driver 230A that controls the power applied to the first movable leg solenoid 1126A and a second solenoid driver 230B that controls the power applied to the second movable leg solenoid 1126B. These solenoid drivers are general driving circuits, so their description will be omitted.

[0081] As in the first embodiment, the first gyro sensor 600A and the second gyro sensor 600B are connected to be able to output the detected angular velocity to the CPU 201 of the robot controller 200. The CPU 201 is also connected to be able to output a PWM control signal command (a pulse width signal) to the first solenoid driver 230A and the second solenoid driver 230B.

[0082] In such first movable leg 120A and second movable leg 120B, the CPU 201 commands the first solenoid driver 230A or the second solenoid driver 230B to drive the first movable leg solenoid 1126A or the second movable leg solenoid 1126B. This changes the magnetic force of the first movable leg 120A or the second movable leg 120B, and the magnetic attraction between them and the floor 2 changes, resulting in a change in the fixing and holding force.

[0083] (Attitude control) As shown in Fig. 13, when the CPU 201 starts this posture control, it first calibrates the first and second gyro sensors 600A, 600B (S201). That is, with the robot arm 10A in the initial position, it performs initial setting assuming that the tilt of the moving platform 100 is in the initial position. Next, it turns off the PWM control commanded to the first and second movable leg solenoids 1126A, 1126B (S202), that is, it performs initial setting of the first and second movable leg solenoids 1126A, 1126B. Then, it waits until it is determined that the posture control should start (N in S203), and when it determines that the posture control should start based on, for example, the start of the drive of the robot arm 10A, it proceeds to step S204.

[0084] When the CPU 201 starts the actual operation of attitude control, it first starts PWM control of the first and second movable leg solenoids 1126A, 1126B (S204), that is, makes the first and second movable leg solenoids 1126A, 1126B capable of generating magnetic force. Next, it reads the values ​​detected by the first and second gyro sensors 600A, 600B (S205) and calculates the tilt (attitude) of the mobile platform 100. Then, from the calculated attitude, the CPU 201 calculates the height of the first movable leg 120A side and the height of the second movable leg 120B side in the X direction of the mobile platform 100.

[0085] Next, the CPU 201 judges whether the first movable leg 120A side is lower or not based on the detection of the first and second gyro sensors 600A, 600B in the moving platform 100 (S206). If the first movable leg 120A side is not lower (N in S206), it then judges whether the second movable leg 120B side is lower or not (S208). If the second movable leg 120B side is not lower either (N in S208), that is, the moving platform 100 is not tilted, so it proceeds to step S210. Then, it judges whether to end the posture control (S210), that is, it judges whether the driving (work) of the robot arm 10A is completed or not, and if the robot arm 10A is being driven, it judges to continue the posture control (N in S210), and returns to step S205.

[0086] Here, for example, when the robot arm 10A moves its tip toward the first movable leg 120A in the X direction to perform a task (see, for example, FIG. 8(c)), the side of the first movable leg 120A on the movable platform 100 becomes lower. Then, the CPU 201 determines that the side of the first movable leg 120A on the movable platform 100 becomes lower based on the respective velocities of the first and second gyro sensors 600A and 600B (Y in S206). In this case, the CPU 201 issues a command to the second movable leg solenoid 1126B to increase the pulse width of the PWM control to increase the magnetic attraction force of the second movable leg 120B. At the same time, the CPU 201 issues a command to the first movable leg solenoid 1126A to decrease the pulse width of the PWM control to decrease the magnetic attraction force of the first movable leg 120A (S207) (holding force changing process). That is, the movable base 100 detects that the position and posture of the robot arm 10A have changed and the center of gravity has moved toward the first movable leg 120A. Then, the movable base 100 suppresses tilting of the movable base 100 by increasing the magnetic force (fixed holding force) of the second movable leg 120B on the opposite side to the floor 2 and decreasing the magnetic force (fixed holding force) of the first movable leg 120A on the floor 2. This prevents the robot system 1 from falling over.

[0087] Also, for example, when the robot arm 10A moves its tip toward the second movable leg 120B in the X direction to perform a task (see, for example, FIG. 8(b)), the second movable leg 120B side of the movable platform 100 becomes lower. Then, the CPU 201 determines that the second movable leg 120B side of the movable platform 100 becomes lower based on the speeds of the first and second gyro sensors 600A and 600B (N in S206, Y in S208). The CPU 201 issues a command to the first movable leg solenoid 1126A to increase the pulse width of the PWM control to increase the magnetic attraction force of the first movable leg 120A. At the same time, the CPU 201 issues a command to the second movable leg solenoid 1126B to decrease the pulse width of the PWM control to decrease the magnetic attraction force of the second movable leg 120B (S209) (holding force changing process). That is, the movable base 100 detects that the position and posture of the robot arm 10A have changed and the center of gravity has moved toward the second movable leg 120B. Then, the movable base 100 suppresses tilting of the movable base 100 by increasing the magnetic force (fixed holding force) of the first movable leg 120A against the floor 2 and decreasing the magnetic force (fixed holding force) of the second movable leg 120B against the floor 2. This prevents the robot system 1 from falling over.

[0088] In this way, each time a tilt of the movable pedestal 100 is detected, the magnetic attraction (fixed holding force) of the first and second movable legs 120A, 120B to the floor 2 is controlled to suppress the tilt, and the process of suppressing the tilt of the movable pedestal 100 is repeated. As a result, the magnetic attraction (fixed holding force) of the first and second movable legs 120A, 120B to the floor 2 is generated to suppress vibrations of the movable pedestal 100 caused by movement of the robot arm 10A. Therefore, vibrations of the movable pedestal 100, particularly in the X direction, can be suppressed.

[0089] After that, when it is determined that the driving (work) of the robot arm 10A is completed, it is determined to end the posture control (Y in S210), and thus the posture control according to this embodiment is ended.

[0090] [Summary of the second embodiment] As described above, in the robot system 1 according to the second embodiment, when the robot system 1 (movable platform 100) is moved, the robot system 1 can be installed simply by raising the casters 191 and grounding the fixed legs 110 and the movable legs 120 on the floor 2. That is, the first and second movable leg solenoids 1126A and 1126B that can change the fixing force with the floor 2 are provided on the movable leg 120, so that the robot system 1 can be prevented from falling over and vibration can be suppressed by the operation of the robot arm 10A. Therefore, the robot system 1 (particularly the robot arm 10A) can be stabilized at the installation location, and it is not necessary to firmly fix it to the floor 2. Therefore, when the robot system 1 (movable platform 100) is moved, it can be easily installed at the installation location, and the time until the start of work can be shortened.

[0091] In addition, in the second embodiment, the magnetic forces generated by the first and second movable leg solenoids 1126A, 1126B can be electrically controlled, so that the response can be improved compared to the air suction unit 125 in the first embodiment. This makes it possible to more stably obtain the effects of preventing the robot system 1 from falling over, suppressing tilting, suppressing vibration, and the like.

[0092] Other configurations, operations, and effects of the second embodiment described above are similar to those of the first embodiment, and therefore description thereof will be omitted.

[0093] <Third embodiment> Next, a third embodiment, which is a partial modification of the second embodiment, will be described with reference to Figs. 14 and 15. Fig. 14(a) is a diagram showing the arrangement positions of the fixed leg, the movable leg, and the gyro sensor in the third embodiment. Fig. 14(b) is a block diagram showing a control system for the movable leg in the third embodiment. Fig. 15 is a flowchart showing attitude control according to the third embodiment.

[0094] In comparison with the second embodiment, the third embodiment includes three movable legs 120 each having a solenoid as a magnetic attraction unit. The magnetic force that magnetically attracts the movable legs 120 to the floor 2 is changed by the magnetic force generated by the solenoid, thereby changing the fixing and holding force of the movable legs 120, thereby suppressing the vibration of the mobile platform 100 in the vertical direction. Note that the third embodiment is also based on the premise that the floor 2 is a magnetic body and that the floor 2 and the movable legs 120 are magnetically attracted to each other by magnetic force. The control configuration and attitude control according to the third embodiment will be described below.

[0095] (Control configuration of the moving platform) First, the configuration of the mobile platform 100 for performing posture control according to the third embodiment and the first movable leg 120A, the second movable leg 120B, and the third movable leg 120C provided thereon will be described. As shown in Fig. 14(a), the mobile platform 100-2 (hereinafter simply referred to as "mobile platform 100") is configured with three movable legs 120 and three fixed legs arranged in the above-mentioned second arrangement pattern (see Fig. 9(b)). Note that the three movable legs 120 are referred to as the first movable leg 120A, the second movable leg 12B, and the third movable leg 120C to distinguish them.

[0096] A gyro sensor 600Z is disposed near the center in the X and Y directions on the upper part of the moving platform 100. The gyro sensor 600Z detects the angular velocity caused by the vertical vibrations occurring in the moving platform 100, and outputs the detected angular velocity to the robot controller 200.

[0097] As shown in FIG. 14(b), the first movable leg 120A is provided with a first movable leg solenoid 1126A having a coil (not shown) that generates a magnetic force as a magnetic attraction part. Similarly, the second movable leg 120B is provided with a second movable leg solenoid 1126B having a coil (not shown) that generates a magnetic force as a magnetic attraction part. Similarly, the third movable leg 120C is provided with a third movable leg solenoid 1126C having a coil (not shown) that generates a magnetic force as a magnetic attraction part. In addition, the movable platform 100 is provided with a first solenoid driver 230A that controls the power applied to the first movable leg solenoid 1126A. Similarly, the movable platform 100 is provided with a second solenoid driver 230B that controls the power applied to the second movable leg solenoid 1126B. Similarly, a third solenoid driver 230C that controls the power applied to a third movable leg solenoid 1126C is provided inside the moving platform 100. These solenoid drivers are general drive circuits, and therefore a description thereof will be omitted.

[0098] The gyro sensor 600Z is connected so as to be able to output the detected angular velocity to the CPU 201 of the robot controller 200. The CPU 201 is also connected so as to be able to output a PWM control signal command (a pulse width signal) to the first solenoid driver 230A, the second solenoid driver 230B, and the third solenoid driver 230C.

[0099] In the first movable leg 120A, the second movable leg 120B, and the third movable leg 120C, the CPU 201 issues a command to the first solenoid driver 230A, the second solenoid driver 230B, or the third solenoid driver 230C. This drives the first movable leg solenoid 1126A, the second movable leg solenoid 1126B, or the third movable leg solenoid 1126C, changing the magnetic force of the first movable leg 120A, the second movable leg 120B, or the third movable leg 120C. Therefore, the magnetic attraction force between the movable legs 120 and the floor 2 changes, and the fixing and holding force changes.

[0100] (Attitude control) As shown in FIG. 15, when the CPU 201 starts this posture control (which is also vibration suppression control in the third embodiment), it first calibrates the gyro sensor 600Z (S301). That is, with the robot arm 10A in the initial position, it performs initial setting assuming that the tilt of the moving platform 100 is in the initial position. Next, it turns off the PWM control commanded to the first to third movable leg solenoids 1126A, 1126B, and 1126C (S302), that is, it performs initial setting of the first to third movable leg solenoids 1126A, 1126B, and 1126C. Then, it waits until it is determined that the posture control is to start (N in S303), and when it determines that the posture control is to start based on, for example, the determination that the robot arm 10A is to start driving, etc. (Y in S303), it proceeds to step S304.

[0101] When the CPU 201 starts the actual attitude control operation, it first reads the value detected by the gyro sensor 600Z (S304) and calculates the Z coordinate of the mobile platform 100 (the position in the up-down direction).

[0102] Next, based on the detection of the gyro sensor 600Z in the moving platform 100, the CPU 201 judges whether the moving platform 100 as a whole is lower in the vertical direction (Z coordinate) than the calibrated position, that is, the position initially set in the above step S301 (S305). If the moving platform 100 has not been lowered (N in S305), the CPU 201 then judges whether the moving platform 100 has been raised (S307). Here, if the moving platform 100 has not been raised (N in S307), that is, the moving platform 100 has not moved up or down, so the CPU 201 proceeds to step S309. Then, the CPU 201 judges whether to end the posture control (S309), that is, whether the driving (work) of the robot arm 10A has been completed, and if the robot arm 10A is being driven, the CPU 201 judges to continue the posture control (N in S309), and returns to step S304.

[0103] Here, for example, suppose that the robot arm 10A is driven to perform a task, and the entire mobile platform 100 is lowered. Then, the CPU 201 determines that the mobile platform 100 has been lowered from the speeds of the gyro sensor 600Z (Y in S305). In this case, the CPU 201 issues a command to the first to third movable leg solenoids 1126A, 1126B, and 1126C to reduce the pulse width of the PWM control to decrease the magnetic attraction of the first to third movable legs 120A, 120B, and 120C (S306) (holding force changing process). That is, the CPU 201 detects that the position and posture of the robot arm 10A have changed, and the mobile platform 100 has moved downward. Then, in the opposite manner, the CPU 201 reduces the magnetic attraction of the first to third movable legs 120A, 120B, and 120C, thereby reducing the downward force of the mobile platform 100. This suppresses the downward movement of the robot system 1.

[0104] Here, for example, suppose that the robot arm 10A is driven to perform a task, and the entire mobile platform 100 becomes higher. Then, the CPU 201 determines that the mobile platform 100 has become higher from the speeds of the gyro sensor 600Z (Y in S307). In this case, the CPU 201 issues a command to increase the magnetic attraction force of the first to third movable legs 120A, 120B, and 120C by increasing the pulse width of the PWM control command issued to the first to third movable leg solenoids 1126A, 1126B, and 1126C (S308) (holding force changing process). That is, the CPU 201 detects that the position and posture of the robot arm 10A have changed, and the mobile platform 100 has moved upward. Then, in the opposite manner, the CPU 201 increases the magnetic attraction force of the first to third movable legs 120A, 120B, and 120C, thereby reducing the upward force of the mobile platform 100. This suppresses the upward movement of the robot system 1.

[0105] In this way, each time vertical movement of the mobile gantry 100 is detected, the magnetic attraction (fixed holding force) of the first to third movable legs 120A, 120B, 120C to the floor 2 is controlled to suppress the movement, and the vertical movement of the mobile gantry 100 is repeatedly suppressed. As a result, the magnetic attraction (fixed holding force) of the first to third movable legs 120A, 120B, 120C to the floor 2 is generated to suppress vertical vibration of the mobile gantry 100 caused by movement of the robot arm 10A. Therefore, vibration of the mobile gantry 100, particularly in the Z direction, can be suppressed.

[0106] After that, when it is determined that the driving (work) of the robot arm 10A is completed, it is determined to end the posture control (Y in S309), and thus the posture control according to this embodiment is ended.

[0107] [Summary of the third embodiment] As described above, in the robot system 1 according to the third embodiment, when the robot system 1 (movable platform 100) is moved, the robot system 1 can be installed simply by raising the casters 191 and grounding the fixed legs 110 and the movable legs 120 on the floor 2. That is, the first to third movable leg solenoids 1126A, 1126B, and 1126C that can change the fixing force with the floor 2 are provided on the movable leg 120, so that the vibration of the robot system 1 can be suppressed by the operation of the robot arm 10A. Therefore, the robot system 1 (particularly the robot arm 10A) can be stabilized at the installation location, and it is not necessary to firmly fix it to the floor 2. Therefore, when the robot system 1 (movable platform 100) is moved, it can be easily installed at the installation location, and the time until the start of work can be shortened.

[0108] Other configurations, operations, and effects of the third embodiment described above are similar to those of the second embodiment, and therefore description thereof will be omitted.

[0109] <Fourth embodiment> Next, a fourth embodiment, which is a partial modification of the third embodiment, will be described with reference to Figs. 16, 17, and 18. Fig. 16(a) is a diagram showing the arrangement positions of the fixed leg, the movable leg, and the gyro sensor in the fourth embodiment. Fig. 16(b) is a block diagram showing the structures of the first movable leg, the second movable leg, and the third movable leg in the fourth embodiment. Fig. 17 is a block diagram showing a control system for the movable legs in the fourth embodiment. Fig. 18 is a flowchart showing attitude control according to the fourth embodiment.

[0110] In comparison with the third embodiment, the fourth embodiment includes three movable legs 120 each having an air cylinder 2128 as a holding force changer. The rigidity of the movable legs 120 is changed by the air cylinder, thereby changing the fixing holding force of the movable legs 120 against the floor 2, and suppressing the vibration of the mobile platform 100 in the vertical direction. In other words, if the rigidity of the movable legs 120 is increased, the legs are less likely to descend even when loaded, and if the rigidity of the movable legs 120 is decreased, the legs are prevented from floating when the load is lightened, that is, the fixing holding force that follows the floor 2 is changed. Also, even if the mobile platform 100 is tilted, the fixing holding force against the floor 2 is increased in terms of the overall balance of the multiple legs. The control configuration and attitude control according to the fourth embodiment will be described below.

[0111] (Control configuration of the moving platform) First, the configuration of the mobile platform 100 for performing posture control according to the fourth embodiment and the first movable leg 120A, the second movable leg 120B, and the third movable leg 120C provided thereon will be described. As shown in Fig. 16(a), the mobile platform 100-2 (hereinafter simply referred to as "mobile platform 100") is configured with three movable legs 120 and three fixed legs arranged in the above-mentioned second arrangement pattern (see Fig. 9(b)). Note that the three movable legs 120 are referred to as the first movable leg 120A, the second movable leg 120B, and the third movable leg 120C to distinguish them.

[0112] A gyro sensor 600Z is disposed as a detection unit near the center in the X and Y directions on the upper part of the moving platform 100. The gyro sensor 600Z detects the angular velocity caused by the vertical vibrations occurring in the moving platform 100, and outputs the angular velocity to the robot controller 200.

[0113] As shown in FIG. 16(b), the first movable leg 120A is provided with a first movable leg direction control valve 2126A connected to a first regulator 800A provided inside the movable platform 100 to receive air pressure. The first movable leg 120A is also provided with a first chamber pressure control valve 2127Aa that adjusts the air pressure from the first movable leg direction control valve 2126A and supplies it to a first chamber 2128Aa of the first air cylinder 2128A. The first movable leg 120A is also provided with a second chamber pressure control valve 2127Ab that adjusts the air pressure from the first movable leg direction control valve 2126A and supplies it to a second chamber 2128Ab of the first air cylinder 2128A. The first air cylinder 2128A has a first chamber 2128Aa, a second chamber 2128Ab, and a first piston 2128Ap disposed between them. A rod (not shown) connected to the first piston 2128Ap is drivingly connected to a grounding portion (not shown) of the first movable leg 120A, that is, the first piston 2128Ap causes the first air cylinder 2128A to transmit a load to the floor 2. The first air cylinder 2128A configured in this manner increases in rigidity when the opposing air pressures in the first chamber 2128Aa and the second chamber 2128Ab increase, and decreases in rigidity when these air pressures decrease.

[0114] Similarly, the second movable leg 120B is provided with a second movable leg direction control valve 2126B connected to a second regulator 800B provided inside the movable platform 100 and supplied with air pressure. The second movable leg 120B is also provided with a first chamber pressure control valve 2127Ba that adjusts the air pressure from the second movable leg direction control valve 2126B and supplies it to a first chamber 2128Ba of the second air cylinder 2128B. The second movable leg 120B is also provided with a second chamber pressure control valve 2127Bb that adjusts the air pressure from the second movable leg direction control valve 2126B and supplies it to a second chamber 2128Bb of the second air cylinder 2128B. The second air cylinder 2128B has a first chamber 2128Ba, a second chamber 2128Bb, and a second piston 2128Bp arranged therebetween. A rod (not shown) connected to the second piston 2128Bp is drivingly connected to a grounding portion (not shown) of the second movable leg 120B, that is, the second piston 2128Bp causes the second air cylinder 2128B to transmit a load to the floor 2. The second air cylinder 2128B configured in this manner increases in rigidity when the opposing air pressures in the first chamber 2128Ba and the second chamber 2128Bb increase, and decreases in rigidity when these air pressures decrease.

[0115] Similarly, the third movable leg 120C is provided with a third movable leg direction control valve 2126C connected to a third regulator 800C provided inside the movable platform 100 to receive air pressure. The third movable leg 120C is also provided with a first chamber pressure control valve 2127Ca that adjusts the air pressure from the third movable leg direction control valve 2126C and supplies it to a first chamber 2128Ca of the third air cylinder 2128C. The third movable leg 120C is also provided with a second chamber pressure control valve 2127Cb that adjusts the air pressure from the third movable leg direction control valve 2126C and supplies it to a second chamber 2128Cb of the third air cylinder 2128C. The third air cylinder 2128C has a first chamber 2128Ca, a second chamber 2128Cb, and a third piston 2128Cp disposed between them. A rod (not shown) connected to the third piston 2128Cp is drivingly connected to a grounding portion (not shown) of the third movable leg 120C, that is, the third air cylinder 2128C transmits a load to the floor 2 by the third piston 2128Cp. The #1 air cylinder 2128C configured in this manner increases in rigidity when the opposing air pressures in the first chamber 2128Ca and the second chamber 2128Cb increase, and decreases in rigidity when these air pressures decrease.

[0116] As shown in FIG. 17, the gyro sensor 600Z is connected to the CPU 201 of the robot controller 200 so as to be able to output the detected angular velocity. The CPU 201 is also connected to the first movable leg direction control valve 2126A, the second movable leg direction control valve 2126B, and the third movable leg direction control valve 2126C so as to be able to output a command signal. The CPU 201 is also connected to the first chamber pressure control valve 2127Aa and the second chamber pressure control valve 2127Ab for the first movable leg so as to be able to output a command signal. The CPU 201 is also connected to the first chamber pressure control valve 2127Ba and the second chamber pressure control valve 2127Bb for the second movable leg so as to be able to output a command signal. The CPU 201 is also connected to the first chamber pressure control valve 2127Ca and the second chamber pressure control valve 2127Cb for the third movable leg so as to be able to output a command signal.

[0117] In the first movable leg 120A, the second movable leg 120B, and the third movable leg 120C, the CPU 201 issues commands to the respective directional control valves, the first chamber pressure control valve, and the second chamber pressure control valve. Then, the rigidity of the first to third air cylinders 2128A, 2128B, and 2128C is changed. Therefore, the fixing force to the floor 2 is changed by changing the rigidity of the movable legs 120.

[0118] (Attitude control) As shown in FIG. 18, when the CPU 201 starts this attitude control (which is also vibration suppression control in the fourth embodiment), it first calibrates the gyro sensor 600Z (S401). That is, with the robot arm 10A in the initial position, it performs initial setting assuming that the tilt of the moving platform 100 is in the initial position. Next, it controls the first to third movable leg directional control valves 2126A, 2126B, 2126C to the side where the first to third movable legs 120A, 120B, 120C do not output pressing force (non-holding side). This causes the first to third movable leg directional control valves 2126A, 2126B, 2126C to be initialized (S402). It also controls the second chamber pressure control valves 2127Ab, 2127Bb, 2127Cb in the first to third movable legs 120A, 120B, 120C. That is, a medium pressure is set as an initial pressure in the second chambers 2128Ab, 2128Bb, and 2128Cb of the first to third air cylinders 2128A, 2128B, and 2128C (S403). Then, the system waits until it is determined that posture control should start (N in S404). After that, it is determined that the robot arm 10A has started to drive, for example, and the like, that it is determined that posture control should start (Y in S404).

[0119] Then, first, the pressures in the second chambers 2128Ab, 2128Bb, and 2128Cb of the first to third air cylinders 2128A, 2128B, and 2128C are set to low pressure (S405). Furthermore, the pressures in the first chambers 2128Aa, 2128Ba, and 2128Ca of the first to third air cylinders 2128A, 2128B, and 2128C are also set to low pressure (S406). Then, the first to third movable leg directional control valves 2126A, 2126B, and 2126C are controlled to the side where the first to third movable legs 120A, 120B, and 120C output a pressing force (large holding force side) (S407). As a result, the first to third movable legs 120A, 120B, and 120C are prepared in a state where their rigidity against the floor 2 is small. Next, the CPU 201 reads the value detected by the gyro sensor 600Z (S408), and calculates the Z coordinate of the moving platform 100 (position in the up-down direction).

[0120] Next, based on the detection of the gyro sensor 600Z in the moving platform 100, the CPU 201 determines whether the moving platform 100 as a whole is lower in the vertical direction (Z coordinate) than the calibrated position, that is, the position initially set in the above step S401 (S409). If the moving platform 100 has not been lowered (N in S409), the CPU 201 then determines whether the moving platform 100 has been raised (S412). Here, if the moving platform 100 has not been raised (N in S412), that is, the moving platform 100 has not moved up or down, so the CPU 201 proceeds to step S415. Then, the CPU 201 determines whether to end the posture control (S415), that is, whether the driving (task) of the robot arm 10A has been completed, and if the robot arm 10A is being driven, the CPU 201 determines to continue the posture control (N in S415), and returns to step S408.

[0121] Here, for example, suppose that the robot arm 10A is driven to perform a task, and the entire movable platform 100 is lowered. Then, the CPU 201 determines that the movable platform 100 has been lowered from the speeds of the gyro sensor 600Z (Y in S409). In this case, the CPU 201 first issues a command to the first to third movable leg direction control valves 2126A, 2126B, and 2126C to control the first to third movable legs 120A, 120B, and 120C to the side that increases the rigidity (large holding force side) (S410). Next, the CPU 201 controls the first chamber pressure control valves 2127Aa, 2127Ba, and 2127Ca in the first to third movable legs 120A, 120B, and 120C. That is, the pressure in the first chambers 2128Aa, 2128Ba, 2128Ca of the first to third air cylinders 2128A, 2128B, 2128C is increased (up) (S411) (holding force changing process). That is, the CPU 201 detects that the position and posture of the robot arm 10A has changed and the moving platform 100 has moved downward. Conversely, the rigidity of the first to third movable legs 120A, 120B, 120C is increased to prevent the downward movement, thereby reducing the downward force of the moving platform 100. This suppresses the downward movement of the robot system 1.

[0122] Also, for example, suppose that the robot arm 10A is driven to perform a task, and the entire movable platform 100 becomes higher. Then, the CPU 201 determines that the movable platform 100 has become higher from the speeds of the gyro sensor 600Z (Y in S412). In this case, first, the CPU 201 issues a command to the first to third movable leg directional control valves 2126A, 2126B, and 2126C to control the first to third movable legs 120A, 120B, and 120C to the side that reduces the rigidity (smaller holding force side) (S413). Next, the CPU 201 controls the second chamber pressure control valves 2127Ab, 2127Bb, and 2127Cb in the first to third movable legs 120A, 120B, and 120C. That is, the pressures in the first chambers 2128Ab, 2128Bb, and 2128Cb of the first to third air cylinders 2128A, 2128B, and 2128C are increased (up) (S414) (holding force changing process). That is, the CPU 201 detects that the position and posture of the robot arm 10A have changed and the moving platform 100 has moved upward. Conversely, the rigidity of the first to third movable legs 120A, 120B, and 120C is reduced so as to prevent the upward movement, thereby reducing the upward force of the moving platform 100. That is, the first to third movable legs 120A, 120B, and 120C are made less likely to float above the floor 2. This suppresses the upward movement of the robot system 1.

[0123] In this way, each time vertical movement of the mobile gantry 100 is detected, the rigidity of the first to third movable legs 120A, 120B, 120C is controlled to suppress the movement, thereby controlling the fixing and holding force against the floor 2, and the vertical movement of the mobile gantry 100 is repeatedly suppressed. As a result, the fixing and holding force of the first to third movable legs 120A, 120B, 120C against the floor 2 is generated to suppress vertical vibration of the mobile gantry 100 caused by movement of the robot arm 10A. Therefore, vibration of the mobile gantry 100, particularly in the Z direction, can be suppressed.

[0124] After that, when it is determined that the driving (work) of the robot arm 10A is completed, it is determined to end the posture control (Y in S415), and thus the posture control according to this embodiment is ended.

[0125] [Summary of the fourth embodiment] As described above, in the robot system 1 according to the fourth embodiment, when the robot system 1 (movable platform 100) is moved, the robot system 1 can be installed simply by raising the casters 191 and grounding the fixed legs 110 and the movable legs 120 on the floor 2. That is, since the first to third air cylinders 2128A, 2128B, and 2128C that can change the fixing force with the floor 2 are provided on the movable legs 120, the vibration of the robot system 1 can be suppressed by the operation of the robot arm 10A. Therefore, the robot system 1 (particularly the robot arm 10A) can be stabilized at the installation location, and it is not necessary to firmly fix it to the floor 2. Therefore, when the robot system 1 (movable platform 100) is moved, it can be easily installed at the installation location, and the time until the start of work can be shortened.

[0126] Other configurations, operations, and effects of the fourth embodiment described above are similar to those of the third embodiment, and therefore description thereof will be omitted.

[0127] <Fifth embodiment> Next, a fifth embodiment, which is a partial modification of the third embodiment, will be described with reference to Figs. 19 and 20. Fig. 19(a) is a diagram showing the arrangement positions of the fixed leg, the movable leg, and the gyro sensor in the fifth embodiment. Fig. 19(b) is a block diagram showing a control system for the movable leg in the fifth embodiment. Fig. 20 is a flowchart showing the initial setting control and the correction control in the fifth embodiment.

[0128] In the fifth embodiment, the amount of change in the movable platform 100 caused by the test operation of the robot arm 10A is measured and stored, and the magnitude of the fixing and holding force of the movable leg 120 is controlled according to the stored amount of change. The magnitude of the fixing and holding force of the movable leg 120 in the fifth embodiment is changed by a magnetic force generated by a solenoid, as in the third embodiment. The fixing and holding force of the movable leg 120 is changed by changing the magnetic force generated by the solenoid, thereby suppressing the vibration in the vertical direction of the movable platform 100. Note that, in the fifth embodiment, it is also assumed that the floor 2 is a magnetic material, and the floor 2 and the movable leg 120 are magnetically attracted to each other by a magnetic force. Hereinafter, the initial setting control and the correction control according to the fifth embodiment will be described.

[0129] (Control configuration of the moving platform) As shown in Fig. 19(a) and Fig. 19(b), the configuration of the movable platform 100 according to the fifth embodiment and the first movable leg 120A, the second movable leg 120B, and the third movable leg 120C provided thereon are basically the same as those of the third embodiment described above. Also, as shown in Fig. 19(b), the CPU 201 is connected to torque sensors 15 as detectors arranged at each joint of the robot arm 10A. Also, the amount of change in the movable platform 100 calculated by the CPU 201 based on the value detected by the gyro sensor 600Z can be stored in the RAM 203.

[0130] (Initial setting control) As shown in Fig. 20, when the CPU 201 starts this control, it first calibrates the gyro sensor 600Z (S501). That is, with the robot arm 10A in the initial position, it performs initial setting assuming that the tilt of the moving platform 100 is in the initial position. Next, it turns off the PWM control commanded to the first to third movable leg solenoids 1126A, 1126B, and 1126C (S502), that is, it performs initial setting of the first to third movable leg solenoids 1126A, 1126B, and 1126C. Then, it starts the robot arm 10A (robot) (S503), and judges whether the start is a test operation in a recording mode, or an operation according to a normal task and not in a recording mode (S504). If the start of the robot arm 10A is a test operation, it is determined that the mode is the recording mode (Y in S504), and the process proceeds to step S505, that is, the initial setting control (control of the recording mode) is performed from step S505 to step S507.

[0131] That is, the CPU 201 drives the robot arm 10A in the same trajectory and posture as the normal operation, but executes a test operation in which the robot arm 10A does not perform the work on the workpiece. Then, the CPU 201 reads the detection result of the gyro sensor 600Z in association with the information of the teaching point of the robot arm 10A (S505). That is, the CPU 201 reads values ​​that detect the vibration, reaction force, and change in the center of gravity position generated in the moving platform 100 according to the trajectory and posture of the robot arm 10A. The information of the teaching point is information such as coordinates that is stored in association with the passing points of the robot arm 10A when the trajectory and posture for performing the work of the robot arm 10A are taught by a teaching pendant or the like.

[0132] That is, the CPU 201 calculates the vibration, reaction force, and center of gravity position occurring in the moving platform 100 from the detection results of the gyro sensor 600Z, and records these values ​​in the RAM 203 (memory) as changes in association with the trajectory and posture of the robot arm 10A (S506). Then, it is determined whether the process of the test operation of the robot arm 10A has ended (S507), and the above recording is continued until the process is ended (N in S507). Thereafter, when the process of the test operation of the robot arm 10A has ended (Y in S507), the above recording is ended, that is, the initial setting control (control in the recording mode) is ended.

[0133] (correction control) Next, the correction control when the robot arm 10A performs actual work instead of the test operation will be described. As shown in FIG. 20, when the CPU 201 starts this control, it calibrates the gyro sensor 600Z in the same manner as described above (S501). That is, in a state where the robot arm 10A is in the initial position, it performs initial setting assuming that the tilt of the moving platform 100 is in the initial position. Next, it turns off the PWM control commanded to the first to third movable leg solenoids 1126A, 1126B, and 1126C (S502), that is, it performs initial setting of the first to third movable leg solenoids 1126A, 1126B, and 1126C. Then, it starts the robot arm 10A (robot) (S503), and judges whether the start is a test operation and a recording mode, or a normal work operation and not a recording mode (S504). If the start of the robot arm 10A is not a test operation but an actual work operation, it is determined that the recording mode is not set (N in S504), and the process proceeds to step S508, that is, the correction control from step S508 to step S511 is performed.

[0134] In the correction control, first, the CPU 201 reads the information on the teaching point from the RAM 203 or the like (S508). Then, the CPU 201 reads the vibration, reaction force, and change in the center of gravity position according to the motion (teaching point) of the robot arm 10A, which were stored in the test motion in the above step S506 (S509). Then, the first to third movable leg solenoids 1126A, 1126B, and 1126C are controlled in accordance with the motion timing of the robot arm 10A (timing of passing the teaching point). That is, the output of the magnetic force of the first to third movable leg solenoids 1126A, 1126B, and 1126C is controlled in a direction (reverse direction) that cancels the above change amount (change information) in accordance with the motion timing of the robot arm 10A (S510) (holding force changing step). Then, it is determined whether or not the process in the work motion of the robot arm 10A has ended (S511), and the above recording is continued until the process ends (N in S511). Thereafter, when the process in the work operation of the robot arm 10A is completed (Y in S511), the correction control ends.

[0135] [Summary of the fifth embodiment] As described above, in the robot system 1 according to the fifth embodiment, the fixing and holding forces of the first to third movable legs 120A, 120B, 120C can be controlled by feedforward control based on the amount of change stored in the test operation. That is, it is possible to more effectively cancel out the vibration, reaction, and center of gravity shift occurring in the moving platform 100 than when feedback control is performed based on the detection result detected by the gyro sensor as in the first to fourth embodiments. Of course, the feedforward control may be combined with feedback control.

[0136] In the robot system 1 according to the fifth embodiment, when the robot system 1 (movable platform 100) is moved, the robot system 1 can be installed simply by raising the casters 191 and grounding the fixed legs 110 and the movable legs 120 on the floor 2. That is, the movable legs 120 are provided with the first to third movable leg solenoids 1126A, 1126B, and 1126C that can change the fixing force with the floor 2, so that the operation of the robot arm 10A can suppress the vibration of the robot system 1, suppress the tilt, and prevent the robot system 1 from falling over. Therefore, the robot system 1 (particularly the robot arm 10A) can be stabilized at the installation location, and it is not necessary to firmly fix the robot system 1 to the floor 2. Therefore, when the robot system 1 (movable platform 100) is moved, it can be easily installed at the installation location, and the time until the start of work can be shortened.

[0137] Other configurations, operations, and effects of the fifth embodiment described above are similar to those of the third embodiment, and therefore description thereof will be omitted.

[0138] Sixth embodiment Next, a sixth embodiment will be described, which is a partial modification of the first to fifth embodiments. In the sixth embodiment, the movable leg 120 is not provided with a configuration for actively changing the fixing and holding force (such as an air suction part, a solenoid, or an air cylinder), but with a configuration for passively changing the fixing and holding force.

[0139] That is, for example, when a robot that is incorporated in a production line and is not moved is fixed on the production line, a rigid body is often fixed using a high-strength metal plate as a spacer. However, in the case of the robot arm 10A mounted on the movable platform 100, the movable platform 100 and the robot arm 10A are firmly fixed. Therefore, the impact of vibration when the caster 191 overcomes a step during movement is directly transmitted to the robot arm 10A, and there is a risk that each joint of the robot arm 10A may be damaged. In addition, in the first to third and fifth embodiments, the fixing force to the floor 2 is generated by air suction or magnetic force, and therefore the fixing force is inferior to that of mechanical fastening such as anchors, so there is a problem that the robot arm 10A is prone to shaking.

[0140] Therefore, in the sixth embodiment, the movable leg 120 is provided with a damper member (damper mechanism) (not shown) having the functions of vibration isolation, vibration removal, and vibration suppression, thereby suppressing the vibration of the movable platform 100 caused by the operation (assembly operation) of the robot arm 10A. That is, the damper member changes the magnitude of the fixing and holding force by changing the damping force according to the application speed of the load generated on the movable leg 120. Furthermore, by providing such a damper member, even if an impact occurs due to a step during the movement of the movable platform 100, the effect of mitigating the impact can be obtained. Note that, as such a damper member, for example, a sheet of gel-like vibration-proof material can be considered.

[0141] In the robot system 1 according to the sixth embodiment, when the robot system 1 (movable platform 100) is moved, the robot system 1 can be installed simply by raising the casters 191 and grounding the fixed legs 110 and the movable legs 120 on the floor 2. That is, the movable legs 120 are provided with damper members capable of changing the fixing and holding force with the floor 2, so that the operation of the robot arm 10A can suppress the vibration of the robot system 1, suppress the tilt, and prevent the robot system 1 from falling over. Therefore, the robot system 1 (particularly the robot arm 10A) can be stabilized at the installation location, and it is not necessary to firmly fix the robot system 1 to the floor 2. Therefore, when the robot system 1 (movable platform 100) is moved, it can be easily installed at the installation location, and the time until the start of work can be shortened.

[0142] Other configurations, operations, and effects of the sixth embodiment described above are similar to those of the first to fifth embodiments, and therefore description thereof will be omitted.

[0143] <Possibilities for other embodiments> In the above-described first and second embodiments, the CPU 201 calculates the inclination of the movable platform 100 from the detection result of the gyro sensor. However, the present invention is not limited to this. The gyro sensor may detect the angular velocity to detect the center of gravity G, and the CPU 201 may calculate, for example, the position of the center of gravity G, and control the magnitude of the fixing force of the movable legs according to the position of the center of gravity G. Furthermore, the first and second embodiments may be combined with the third to fifth embodiments, that is, the gyro sensor that detects the inclination may also detect vibration. Specifically, the CPU 201 may calculate, for example, the inclination and vibration of the movable platform 100 from the detection value of the gyro sensor, and control the magnitude of the fixing force of the movable legs according to the inclination and vibration.

[0144] In the first to fifth embodiments, a gyro sensor has been described as an example of a sensor for detecting tilt or vibration, but this is not limiting and other sensors may be used to detect tilt, center of gravity, or vibration. For example, the values ​​of torque sensors arranged at each joint of the robot arm 10A may be used. Furthermore, the moving platform 100 may be provided with a speed sensor for detecting the speed of the moving platform 100, an acceleration sensor for detecting the acceleration of the moving platform 100, or a current detection element for detecting a current that changes in response to the fluctuation (vibration) of the moving platform 100.

[0145] In the first to fourth embodiments, the tilt of the movable platform 100, the center of gravity of the robot arm 10A, the vibration of the movable platform 100, etc. are detected from the detection results of a sensor such as a gyro sensor. However, the present invention is not limited to this, and it is also possible to calculate the tilt, center of gravity, vibration, etc. from the trajectory and posture (information of the teaching point) of the robot arm 10A that are determined according to the work of the robot arm 10A. In other words, in this case, it also includes a case where the fixing and holding force of the movable legs is changed only by the calculation of the robot controller 200 without providing a sensor or the like on the movable platform 100.

[0146] In the first to sixth embodiments, the holding force changer, such as an air suction unit, solenoid, air cylinder, or vibration isolator, that changes the holding force is provided on the movable leg 120. However, it is not limited to the movable leg 120, and may be provided on the fixed leg 110, that is, it is sufficient that at least one of the multiple legs is provided with a holding force changer. Particularly in this case, all of the multiple legs may be fixed legs or movable legs.

[0147] In the first and fourth embodiments, the air pressure from the regulator is supplied to the pressure control valve. However, an accumulator may be provided between them to improve the response of the pressure supply.

[0148] In addition, in the first to sixth embodiments, the tasks performed by the robot system 1 have been described as being such as assembling a pin to an assembly workpiece and assembling a connector to a circuit board, but the tasks are not limited to these, and any task may be performed.

[0149] In addition, the present disclosure is not limited to the above-described embodiments, and the embodiments can be modified in many ways within the technical concept of the present disclosure. For example, at least two of the above-described embodiments and modifications may be combined. In addition, the effects described in the present embodiment are merely a list of the most preferable effects resulting from the embodiments of the present disclosure, and the effects of the embodiments of the present disclosure are not limited to those described in the present embodiment.

[0150] In the above-mentioned first to sixth embodiments, the robot body (or simply the robot) is a vertically articulated robot, but the present invention is not limited to this. The robot body (or simply the robot) may be, for example, a horizontally articulated robot, a parallel link robot, or an orthogonal robot. The above-mentioned embodiments are applicable to a machine that can automatically perform the actions of expanding and contracting, bending and stretching, moving up and down, moving left and right, or turning, or a combination of these actions, based on information in a storage device provided in a control device.

[0151] The present disclosure can also be realized by a process in which a program for implementing one or more functions of the above-described embodiments is supplied to a system or device via a network or a storage medium, and one or more processors in a computer of the system or device read and execute the program. It can also be realized by a circuit (e.g., ASIC) that implements one or more functions.

[0152] <Disclosure of the Present Embodiment> [Configuration 1] Robots and a mobile platform having a plurality of legs that can be placed on a floor or the ground and an installation section on which the robot is installed, the mobile platform being movable relative to the floor or the ground; At least one of the plurality of legs has a holding force change unit that changes a fixing holding force between the plurality of legs and a floor or ground in accordance with a state of the robot. A robot system comprising: [Configuration 2] The moving platform has a frame portion supporting the plurality of legs, The plurality of legs include fixed legs whose vertical length is invariable with respect to the frame portion, and movable legs whose vertical length is variable with respect to the frame portion. 2. The robot system according to configuration 1. [Configuration 3] The holding force change unit is provided on the movable leg. 3. The robot system according to configuration 2. [Configuration 4] the plurality of legs includes three or more of the fixed legs and two or more of the movable legs; When viewed from the top-bottom direction, the installation section is disposed inside a figure formed by connecting three or more of the fixed legs with lines as vertices, Two or more of the movable legs are arranged outside the figure. 4. The robot system according to configuration 3. [Configuration 5] a control unit for controlling the magnitude of the fixing holding force in the holding force changing unit, 5. The robot system according to any one of configurations 1 to 4. [Configuration 6] The holding force changing unit is an air suction unit that changes the magnitude of the fixed holding force by changing the suction force to the floor or ground by air. 6. The robot system according to configuration 5. [Configuration 7] The holding force changing unit is a magnetic attraction unit that changes the magnitude of the fixed holding force by changing the attraction force to the floor or ground by magnetic force. 6. The robot system according to configuration 5. [Configuration 8] The holding force changing unit is an air cylinder that changes the magnitude of the fixing holding force by changing the rigidity. 6. The robot system according to configuration 5. [Configuration 9] a detection unit that detects a change in a state of the moving platform that changes in response to a position and a posture of the robot; The control unit controls the magnitude of the fixing holding force in the holding force changing unit in response to a detection result by the detection unit. 9. The robot system according to any one of configurations 6 to 8. [Configuration 10] The detection unit detects a center of gravity position of the moving platform that changes depending on a position and a posture of the robot, The control unit controls the magnitude of the fixing holding force in the holding force changing unit in response to a change in the center of gravity position detected by the detection unit. 10. The robot system according to configuration 9. [Configuration 11] The detection unit detects vibrations in the moving platform that change depending on a position and a posture of the robot, The control unit controls the magnitude of the fixing holding force in the holding force changing unit in response to the vibration detected by the detection unit. 11. The robot system according to configuration 9 or 10. [Configuration 12] the detection unit is a torque sensor arranged at a joint of the robot, a gyro sensor arranged at the moving platform, a speed sensor arranged at the moving platform, an acceleration sensor arranged at the moving platform, or a current detection element arranged at the moving platform and detecting a current that changes in response to a movement of the moving platform; 12. The robot system according to any one of configurations 9 to 11. [Configuration 13] the control unit stores an amount of change in a state of the moving platform when the robot is caused to perform a test operation of a task, and when the robot is caused to perform a task, controls a magnitude of the fixed holding force in the holding force changing unit in accordance with the amount of change stored. 13. The robot system according to any one of configurations 5 to 12. [Configuration 14] The holding force change unit is a damper member that changes a damping force in response to an application speed of a load generated on the leg to change a magnitude of the fixed holding force. 5. The robot system according to any one of configurations 1 to 4. [Configuration 15] A vibration isolation mechanism, a vibration removal mechanism, or a vibration damping mechanism is provided between the installation unit of the moving platform and the robot. 15. A robot system according to any one of configurations 1 to 14. [Configuration 16] The moving platform is Casters that enable the movable stand to move by rolling; and a switching mechanism that can switch between an advanced position where the caster is advanced below the leg and a retracted position where the caster is retracted above the leg. 16. A robot system according to any one of configurations 1 to 15. [Method 17] Robots and A movable platform having a plurality of legs that can be placed on a floor or the ground and an installation section on which the robot is installed, the movable platform being movable relative to the floor or the ground; A control unit, A method for controlling a robot system, wherein at least one of the plurality of legs has a holding force change unit that changes a fixed holding force between the plurality of legs and a floor or ground, The control unit includes a holding force changing step of controlling the magnitude of the fixed holding force in the holding force changing unit according to a state of the robot. A method for controlling a robot system comprising: [Configuration 18] A mobile platform on which a robot is installed and which is movable relative to a floor or ground, A plurality of legs are provided which can be placed on a floor or ground, At least one of the plurality of legs has a holding force change unit that changes a fixing holding force between the plurality of legs and a floor or ground in accordance with a state of the robot. A mobile stand characterized by: [Method 19] A method for controlling a mobile platform, the mobile platform comprising: a plurality of legs capable of contacting a floor or the ground; and an installation unit on which a robot is installed; the mobile platform being movable relative to the floor or the ground, at least one of the plurality of legs having a holding force change unit that changes a fixed holding force between the plurality of legs and the floor or the ground; and the mobile platform being controlled by a control unit, the method comprising the steps of: The control unit includes a holding force changing step of controlling the magnitude of the fixed holding force in the holding force changing unit according to a state of the robot. A method for controlling a moving platform. [Configuration 20] 17. A method for manufacturing an article, comprising the steps of: manufacturing an article using a robot system according to any one of configurations 1 to 16; [Configuration 21] A program for causing a computer to execute the control method for a robot system according to Method 17. [Configuration 22] A computer-readable recording medium storing the program according to configuration 21. [Explanation of symbols]

[0153] 1...Robot system / 2...Floor / 10A...Robot (robot arm) / 15...Torque sensor (detection unit) / 100...Mobile stand / 101...Installation unit / 110...Fixed legs (legs) / 110F...Frame unit / 120...Movable legs (legs) / 125...Air suction unit (holding force change unit) / 191...Caster / 195...Lifting mechanism (switching mechanism) / 201...CPU (control unit) / 600...Gyro sensor (detection unit) / 900...Graphic design / 1126...Solenoid (magnetic suction unit, holding force change unit) / 2128...Air cylinder (holding force change unit) / G...Center of gravity position

Claims

1. Robots and a mobile platform having a plurality of legs that can be placed on a floor or the ground and an installation section on which the robot is installed, the mobile platform being movable relative to the floor or the ground; At least one of the plurality of legs has a holding force change unit that changes a fixing holding force between the plurality of legs and a floor or ground in accordance with a state of the robot. A robot system comprising:

2. The moving platform has a frame portion supporting the plurality of legs, The plurality of legs include fixed legs whose vertical length is invariable with respect to the frame portion, and movable legs whose vertical length is variable with respect to the frame portion.

2. The robot system according to claim 1 .

3. The holding force change unit is provided on the movable leg.

3. The robot system according to claim 2.

4. the plurality of legs includes three or more of the fixed legs and two or more of the movable legs; When viewed from the top-bottom direction, the installation section is disposed inside a figure formed by connecting three or more of the fixed legs with vertices by lines, Two or more of the movable legs are arranged outside the figure.

4. The robot system according to claim 3.

5. a control unit for controlling the magnitude of the fixing holding force in the holding force changing unit, 2. The robot system according to claim 1 .

6. The holding force changing unit is an air suction unit that changes the magnitude of the fixed holding force by changing the suction force to the floor or ground by air.

6. The robot system according to claim 5.

7. The holding force changing unit is a magnetic attraction unit that changes the magnitude of the fixed holding force by changing the attraction force to the floor or ground by magnetic force.

6. The robot system according to claim 5.

8. The holding force changing unit is an air cylinder that changes the magnitude of the fixing holding force by changing the rigidity.

6. The robot system according to claim 5.

9. a detection unit that detects a change in a state of the moving platform that changes in response to a position and a posture of the robot; The control unit controls the magnitude of the fixing holding force in the holding force changing unit in response to a detection result by the detection unit.

7. The robot system according to claim 6.

10. The detection unit detects a center of gravity position of the moving platform that changes depending on a position and a posture of the robot, The control unit controls the magnitude of the fixing holding force in the holding force changing unit in response to a change in the center of gravity position detected by the detection unit. The robot system according to claim 9 .

11. The detection unit detects vibrations in the moving platform that change depending on a position and a posture of the robot, The control unit controls the magnitude of the fixing holding force in the holding force changing unit in response to the vibration detected by the detection unit. The robot system according to claim 9 .

12. the detection unit is a torque sensor arranged at a joint of the robot, a gyro sensor arranged at the moving platform, a speed sensor arranged at the moving platform, an acceleration sensor arranged at the moving platform, or a current detection element arranged at the moving platform and detecting a current that changes in response to a movement of the moving platform; The robot system according to claim 9 .

13. the control unit stores an amount of change in a state of the moving platform when the robot is caused to perform a test operation of a task, and when the robot is caused to perform a task, controls a magnitude of the fixed holding force in the holding force changing unit in accordance with the amount of change stored.

6. The robot system according to claim 5.

14. The holding force change unit is a damper member that changes a damping force in response to an application speed of a load generated on the leg to change a magnitude of the fixed holding force.

2. The robot system according to claim 1 .

15. A vibration isolation mechanism, a vibration removal mechanism, or a vibration damping mechanism is provided between the installation unit of the moving platform and the robot.

2. The robot system according to claim 1 .

16. The moving platform is Casters that enable the movable stand to move by rolling; and a switching mechanism that can switch between an advanced position where the caster is advanced below the leg and a retracted position where the caster is retracted above the leg.

2. The robot system according to claim 1 .

17. Robots and A movable platform having a plurality of legs that can be placed on a floor or the ground and an installation section on which the robot is installed, the movable platform being movable relative to the floor or the ground; A control unit, A method for controlling a robot system, wherein at least one of the plurality of legs has a holding force change unit that changes a fixed holding force between the plurality of legs and a floor or ground, The control unit includes a holding force changing step of controlling the magnitude of the fixed holding force in the holding force changing unit according to a state of the robot. A method for controlling a robot system comprising:

18. A mobile platform on which a robot is installed and which is movable relative to a floor or ground, A plurality of legs are provided which can be placed on a floor or ground, At least one of the plurality of legs has a holding force change unit that changes a fixing holding force between the plurality of legs and a floor or ground in accordance with a state of the robot. A mobile stand characterized by:

19. A method for controlling a mobile platform, the mobile platform comprising: a plurality of legs capable of contacting a floor or the ground; and an installation unit on which a robot is installed; the mobile platform being movable relative to the floor or the ground, at least one of the plurality of legs having a holding force change unit that changes a fixed holding force between the plurality of legs and the floor or the ground; and the mobile platform being controlled by a control unit, the method comprising the steps of: The control unit includes a holding force changing step of controlling the magnitude of the fixed holding force in the holding force changing unit according to a state of the robot. A method for controlling a moving platform.

20. A method for manufacturing an article, comprising the steps of: manufacturing an article by using the robot system according to claim 1;

21. A program for causing a computer to execute the control method for a robot system according to claim 17.

22. A computer-readable recording medium storing the program according to claim 21.

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