Robotic system and robot

Abstract

The present invention relates to a robot system and a robot. The robot system of the present invention comprises: a sensor (60) for acquiring data for detecting at least the position of a moving object (O); a robot (10) equipped with a tool (30) and performing a predetermined operation on the object (O) using the tool (30); and a control unit for controlling a tool moving device (40), the tool (30), or an arm member at the front end side of an arm (12) of the robot (10) with a tool control cycle shorter than the control cycle of the robot (10), wherein the tool moving device (40) moves the tool (30) relative to the robot (10).

Description

Technical Field

[0001] The present invention relates to a robot system and a robot. Background Art

[0002] Conventionally, there is known a robot system that uses a tool provided at a front end of the robot to perform a predetermined operation on an object being transported by a transport device (see, for example, Patent Document 1).

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2013-000861 Summary of the invention

[0006] Problems to be solved by the invention

[0007] In the robot system, image data captured by a camera disposed above the transport device is sent to a robot control device, which detects an object on the transport device based on the image data and controls the robot arm according to the detection result. In addition, a device for rotating a tool around a vertical axis is installed at the front end of the robot arm, and the device is also controlled by the robot control device together with the robot arm.

[0008] However, for example, when the object is shaken irregularly on the transport device due to the transport device, or when multiple objects being transported are in contact with each other and the objects are in complex motion on the transport device, the tool at the front end of the arm cannot accurately track the object. This is because the control of the robot control device is not fast enough to respond to such random motions.

[0009] In order to solve this problem, it is also possible to shorten the control cycle of the robot control device. However, if the robot control cycle is to be shortened, the components and equipment used in the robot arm must also adapt to the shortened control cycle. It is also necessary to change the specifications and performance of the motor. In order to make the front end of the arm move at a high acceleration according to the movement of the object, it is necessary to achieve high rigidity of the arm parts, large-scale and high-performance motors for the arm, etc., which requires large-scale modification or design changes of the arm as a whole, and high costs.

[0010] The present invention has been made in view of the above circumstances. One object of the present invention is to provide a robot system and a robot that can make the position of a tool track an object that moves randomly with high accuracy without excessively shortening the control cycle of the robot.

[0011] Solutions for solving problems

[0012] In order to solve the above problems, the present invention can adopt the following solutions.

[0013] The robot system of the first scheme of the present invention comprises: a sensor, which acquires data for detecting at least the position of an object moved by a moving unit, and the moving unit moves the object; a robot, which is equipped with a tool and uses the tool to perform a predetermined operation on the object; and a control unit, which controls a tool moving device, the tool, or an arm part on the front end side of the arm of the robot based on the data and with a tool control cycle shorter than the control cycle of the robot. The tool moving device is used to move the tool relative to the robot.

[0014] For example, when the object shakes irregularly on the mobile unit and the cycle of its motion changes is shorter than the control cycle of the robot, the robot's motion cannot be coordinated with the object. This is the same as the limit of the motion that can be recognized by the human eye and brain. Therefore, although the robot can move the tool to the approximate position of the object, it cannot coordinate the position of the tool with the object's motion with high precision. In the above scheme, the tool mounted on the robot is controlled by the control unit and the tool control cycle is used, and the tool control cycle is shorter than the robot control cycle. Therefore, without shortening the robot's control cycle, the tool position can track the object on the mobile unit with high precision.

[0015] In the above scheme, preferably, the sensor acquires the data in a cycle shorter than the control cycle of the robot, and the robot control device that controls the robot controls the robot in a cycle longer than the control cycle of the tool and uses the data received sequentially from the sensor.

[0016] According to this scheme, it is not necessary to generate tool control data and arm control data separately in the sensor, and the control of the robot control device is performed with a control cycle longer than the tool control cycle.

[0017] In the above aspect, preferably, the tool moving device moves the sensor together with the tool.

[0018] In this scheme, the sensor moves with the tool, so the position of the tool relative to the sensor is constant. Therefore, the movement of the tool can be directly detected by the sensor, and the position of the object relative to the sensor is directly related to the position of the object relative to the tool. This scheme is conducive to achieving accurate control, high-speed control, simplification of control, etc.

[0019] In the above aspect, preferably, when the position of the object detected based on the data changes beyond a predetermined reference, at least one of the robot and the tool performs an abnormality handling operation.

[0020] This solution is conducive to effectively preventing damage to robots, tools, handling devices, objects, etc.

[0021] The second scheme of the present invention is a robot comprising: an arm, which is equipped with a tool and uses the tool to perform a predetermined operation on an object moved by a moving unit, and the moving unit moves the object; a sensor, which is installed on the arm or the tool and obtains data for detecting at least the position of the object moved by the moving unit; and a control unit, which controls a tool moving device, the tool, or an arm part on the front end side of the arm based on the data and with a tool control cycle shorter than the control cycle of the robot, and the tool moving device is used to move the tool relative to the arm.

[0022] In this scheme, the tool mounted on the arm is controlled by the control unit using a tool control cycle which is shorter than the arm control cycle. Therefore, the position of the tool can track the object on the mobile unit with high accuracy without shortening the robot control cycle.

[0023] In the above scheme, preferably, the sensor acquires the data in a cycle shorter than the control cycle of the robot, and the robot control device that controls the robot controls the robot in a cycle longer than the control cycle of the tool and uses the data received sequentially from the sensor.

[0024] According to this scheme, it is not necessary to generate tool control data and arm control data separately in the sensor, and the control of the robot control device is performed with a control cycle longer than the tool control cycle.

[0025] In the above aspect, preferably, the tool moving device moves the sensor together with the tool.

[0026] In this scheme, the sensor moves with the tool, so the position of the tool relative to the sensor is constant. Therefore, the movement of the tool can be directly detected by the sensor, and the position of the object relative to the sensor is directly related to the position of the object relative to the tool. This scheme is conducive to achieving accurate control, high-speed control, simplification of control, etc.

[0027] Effects of the Invention

[0028] According to the present invention, the position of a tool can be made to track an object on a transport device with high accuracy without excessively shortening the control cycle of the robot. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1It is a block diagram showing a robot system according to a first embodiment of the present invention.

[0030] Figure 2 It is a block diagram of the tool control device of the robot system according to the first embodiment.

[0031] Figure 3 It is a block diagram of the robot control device of the robot system according to the first embodiment.

[0032] Figure 4 This is a flowchart showing a processing example of the robot control device and the tool control device according to the first embodiment.

[0033] Figure 5 It is a block diagram showing a robot system according to a second embodiment of the present invention.

[0034] Figure 6 It is a block diagram showing a robot system according to a third embodiment of the present invention.

[0035] Description of Reference Numerals

[0036] 2: Transport device (mobile unit)

[0037] 2a: Motor

[0038] 10: Robots

[0039] 11: Servo motor

[0040] 12: Arm

[0041] 13: Flange parts

[0042] 20: Robot control device

[0043] 21: Robot control unit

[0044] 23: Storage

[0045] 23a: System Programs

[0046] 23b: Action Program

[0047] 30: Tools

[0048] 31: Slider

[0049] 32: Tool body

[0050] 32a: Base

[0051] 32b: Adsorption part

[0052] 32c: Sensor

[0053] 33: Pipeline

[0054] 34: Attraction device

[0055] 40: Tool moving device

[0056] 41: Mobile device body

[0057] 42: Ball screw

[0058] 43: Motor

[0059] 50: Tool control device

[0060] 51: Control Department

[0061] 53: Storage

[0062] 53a: System Programs

[0063] 53b: Tracking Control Procedure

[0064] 60: Sensor

[0065] 61: Processor

[0066] 62: RAM

[0067] 63: Memory

[0068] O: Object DETAILED DESCRIPTION

[0069] A robot system according to a first embodiment of the present invention will be described below with reference to the drawings.

[0070] like Figure 1 As shown, the robot system of this embodiment comprises: a conveying device (moving unit) 2 driven by a motor 2a and used to convey an article, i.e., an object O; a robot 10 that performs a predetermined operation on the object O conveyed by the conveying device 2; a robot control device 20 possessed by the robot 10; a tool 30 provided at the front end of the robot 10; and a sensor 60 for detecting at least the position of the object O moved by the conveying device 2. In this embodiment, the following method is adopted: the conveying direction of the conveying device 2 is Figure 1 The X-axis direction of the reference coordinate system 201 is consistent with that of Figure 1 The Z-axis direction of the reference coordinate system 201 is consistent, Figure 1 The Y-axis direction of the reference coordinate system 201 coincides with the width direction of the conveying device 2 .

[0071] The sensor 60 is a two-dimensional camera, a three-dimensional camera, a three-dimensional distance sensor, etc., and other sensors that can obtain data for detecting the position of the object O can also be used. The sensor 60 of this embodiment is a two-dimensional camera, and the sensor 60 is installed at the front end of the robot 10. The sensor 60 includes: a processor 61; a RAM 62; and a memory 63 storing an image processing program 63a. The processor 61 performs blob processing of the detection object O based on the image processing program 63a, for example, using image processing such as pattern matching processing and binarization processing, and performs detection processing on the center of gravity position, the position of the feature point, etc. of the detected object O. The data of the sensor 60 is sent to the robot control device 20 and the tool control device 50 described below. The control cycle of the processor 61 is shorter than the control cycle of the robot control unit 21 of the robot control device 20, and the control cycle is, for example, 1 millisecond. As the frame rate of the sensor 60 increases, the control cycle can be further shortened.

[0072] The robot 10 is not limited to a specific type of robot, but the robot 10 of the present embodiment includes: a plurality of servo motors 11 (see Figure 3 ). In addition, the arm 12 of the robot 10 is composed of a plurality of movable parts. Each servo motor 11 has a working position detection device for detecting its working position, and an example of the working position detection device is an encoder. The detection value of the working position detection device is sent to the robot control device 20.

[0073] When the reference coordinate system 201 is set in the robot control device 20, a setting tool temporarily set at the front end of the robot 10 contacts a plurality of predetermined positions of a calibration fixture set at a certain position on the conveying device 2. In the present embodiment, the position of the reference coordinate system 201, i.e., the origin position, is a predetermined position on the calibration fixture.

[0074] Furthermore, when setting the reference coordinate system 201 , a jig different from the calibration jig may be used.

[0075] Furthermore, instead of directly contacting the calibration jig with the setting tool, the reference coordinate system 201 may be set by indirectly measuring a predetermined position using a position measuring tool.

[0076] In addition, in the robot control device 20, the reference coordinate system 201 is associated with the current position and posture of the sensor 60 (sensor coordinate system 202). For example, by using a setting tool temporarily set at the front end of the robot 10, a predetermined part of the calibration fixture is contacted, and the position of the calibration fixture observed from the reference coordinate system 201 is calculated. Then, the sensor 60 detects the image of the calibration fixture, the position of the feature points, etc., and sets the installation position and posture of the camera in the robot 10 (sensor coordinate system 202). This is also equivalent to finding the positional relationship between the front end coordinate system 205 of the robot and the sensor coordinate system 202. In addition, adjustment parameters for eliminating distortion of the lens, etc. are also found.

[0077] Thus, even if the position of the robot 10 changes, the robot control device 20 can know the position and posture of the sensor 60 and can convert the detection result obtained by the sensor 60 into a result observed from the reference coordinate system 201 with high accuracy.

[0078] Furthermore, in at least one of the robot control device 20 and the tool control device 50 described below, the robot 10 (reference coordinate system 201) and the position and posture (tool tip coordinate system 206) of the tool body 32 in the tool 30 are associated. With regard to this association, for example, the robot control device 20 calculates in advance the position and posture (tool tip coordinate system 206) of the front end portion of the tool body 32 set at a certain position relative to the front end portion of the robot 10, while the tool 30 is stopped at a predetermined position. In this case, the tool control device 50 described below obtains the current position of the tool tip coordinate system 206 from the robot control device 20, and calculates the position of the front end of the tool body 32 observed from the reference coordinate system 201 using the movement amount of the tool body 32 in the tool 30. For example, when the robot control device 20 can calculate the current position of the tool tip coordinate system 206 every 1 millisecond from the detection results of each working position detection device, the tool control device 50 can also calculate the position of the front end of the tool body 32 every 1 millisecond. In addition, the tool control device 50 can also refer to the detection results of each working position detection device every 1 millisecond and calculate the position of the front end of the tool body 32. This is equivalent to the tool control device 50 calculating the position of the tool tip coordinate system 206 observed from the reference coordinate system 201 by using the movement amount and the current position of the tool tip coordinate system 206. Therefore, the tool control device 50 can control the position of the tool tip coordinate system 206 so as to approach the target position on the reference coordinate system 201.

[0079] Furthermore, the robot control device 20 can also acquire the amount of movement of the tool body 32 from the tool control device 50 , and can calculate the current position of the tool tip coordinate system 206 in a long control cycle.

[0080] As a result, the robot can be controlled in a long cycle in such a way that the tool tip coordinate system 206 approaches the target position.

[0081] A tool 30 is attached to a front end portion of an arm 12 of the robot 10 via a tool moving device 40 . The tool moving device 40 and the tool 30 are controlled by a tool control device 50 .

[0082] The tool moving device 40 includes: a moving device body 41 fixed to the front end of the arm 12; a ball screw 42 supported by the moving device body 41 in a rotatable manner; and a motor 43 such as a servo motor supported by the moving device body 41 and rotating the ball screw 42. In the present embodiment, the central axis 42a of the ball screw 42 is not parallel to the central axis 13a of the flange member 13, which is the movable part at the front end side of the arm 12, and in the present embodiment, extends in a direction that is approximately 90° different from the central axis 13a. The servo motor 43 has a working position detection device for detecting its working position, and the detection value of the working position detection device is sent to the tool control device 50.

[0083] The tool 30 includes: a slider 31 supported by a moving device body 41 in a manner movable in the direction of a central axis 42a; and a tool body 32 supported by the slider 31. In the present embodiment, the tool body 32 supports the object O by adsorption, and includes: a base portion 32a fixed to the slider 31; a suction cup-shaped adsorption portion 32b provided at the lower end of the base portion 32a; and a sensor 32c such as a pressure sensor for detecting adsorption of the object O by the adsorption portion 32b. The detection result of the sensor 32c is transmitted to the robot control device 20. The adsorption portion 32b is formed of a material having rubber-like elasticity, for example. A suction device 34 is connected to the internal space of the base portion 32a via a pipe 33, and the internal space of the base portion 32a is connected to the concave portion of the adsorption portion 32b. Therefore, when the air is sucked by the suction device 34 in a state where the adsorption portion 32b is in contact with the upper surface of the object O, the object O is supported by the tool body 32.

[0084] like Figure 2As shown, the tool control device 50 includes: a control unit 51 including a CPU, a RAM, etc.; a display device 52; a storage unit 53 including a nonvolatile memory, a ROM, etc.; a servo controller 54 for controlling the motor 43 of the tool moving device 40; and an input unit 55. The tool control device 50 receives the detection result of the sensor 60 at each control cycle (1 millisecond) of the sensor 60, controls the motor 43 of the tool moving device 40 with a control cycle (tool control cycle) that is the same as or similar to the sensor 60, and also controls the suction device 34 of the tool 30.

[0085] The storage unit 53 stores a system program 53a for carrying out basic functions of the tool control device 50. The storage unit 53 also stores a tracking control program 53b.

[0086] like Figure 3 As shown, the robot control device 20 includes: a robot control unit 21 having a processor, RAM, etc.; a display device 22; a storage unit 23 having a non-volatile memory, ROM, etc.; a plurality of servo controllers 24 corresponding to the servo motors 11 of the robot 10; and an input unit 25 such as an operation panel. The control cycle of the robot control device 20 is, for example, 10 milliseconds, which is longer than the control cycle of the sensor 60 and the tool control device 50. In addition, the control of the robot control device 20 for moving the arm 12 to the target position is relatively complicated. The control needs to determine the optimal route and calculate the drive amount and drive speed of each servo motor 11 based on the route, so the cost for shortening the control cycle of the robot control device 20 is not cheap.

[0087] The storage unit 23 stores a system program 23a, which assumes the basic functions of the robot control device 20. In addition, the storage unit 23 stores an action program 23b and a tracking control program 23c. The robot control device 20 controls the servo motors 11 of the robot 10, and the tool control device 50 controls the tool moving device 40 and the tool 30, thereby performing the removal operation of the object O transported by the transport device 2.

[0088] In reference Figure 4 , and also explains the processing of the robot control unit 21 based on the action program 23b and the tracking control program 23c, and the processing of the control unit 51 based on the tracking control program 53b when performing the operation.

[0089] First, the robot control unit 21 places the front end of the robot 10 at a predetermined position above the transport device 2 (step S1-1). In this way, the position of the sensor 60 when the front end of the robot 10 is placed is a position where the object O transported by the transport device 2 enters the sensor 60's field of view.

[0090] Next, when the robot control device 20 receives the detected position of the object O from the sensor 60 (step S1-2), the robot control unit 21 starts the first tracking control based on the detected position of the object O and by controlling the robot 10, and the first tracking control is used to make the position of the tool body 32 in the X-axis direction and the Y-axis direction approach and track the position of the object O (step S1-3). At this time, the central axis 42a of the ball screw 42 of the tool moving device 40 is parallel to the X-axis.

[0091] Although there are various controls for implementing the first tracking control, for example, the following two controls can be used. In the present embodiment, the former control is referred to as an image-based method, and the latter control is referred to as a position-based method. In both controls of the present embodiment, the position and posture of the object O are detected by the sensor 60, but the position and posture of the object O may be detected by the robot control device 20 or the tool control device 50 based on the data obtained by the sensor 60.

[0092] The control based on the image method is to control the robot 10 so that the characteristic shape, characteristic points, center of gravity position, etc. of the object O are always arranged at a predetermined position within the field of view of the sensor 60, which is installed on the front end of the robot 10, thereby making the sensor 60 track the object O, and making the set position of the reference coordinate system 201 linked with the position of the sensor 60 or the position of the front end of the robot 10 during tracking. Therefore, the set position of the reference coordinate system 201 moves sequentially as the object O moves, and the robot 10 performs operations while tracking the object O through the action program 23b taught based on the reference coordinate system 201.

[0093] On the other hand, the control based on the position method is to sequentially detect the position of the object O on the reference coordinate system 201 from the data obtained by the sensor 60, calculate the correction amount in a manner close to the target position based on the detected position, and control the robot 10.

[0094] Depending on the type of work performed by the robot 10 , in step S1 - 3 , the robot 10 may move the tool 30 in the X-axis direction at a constant speed or may place the tool 30 at a predetermined position.

[0095] Based on the action program 23b, the robot control unit 21 starts to move the front end of the robot 10 downward so that the suction portion 32b of the tool body 32 contacts the upper surface of the object O (step S1-4). In addition, when the front end of the robot 10 moves downward, the control unit 51 starts a second tracking control, which tracks the position of the tool body 32 in the X-axis direction based on the detection position of the object O received from the sensor 60 (step S2-1). Then, the robot control unit 21 or the control unit 51 activates the suction device 34 (step S2-2). In addition, step S2-2 can be executed before the tool body 32 is set at the target position in the following step S2-5.

[0096] There are various methods for implementing the second tracking control, but the second tracking control can be implemented by, for example, the following method: Since the following method performs control based on the detected position of the object O on the reference coordinate system 201 , this embodiment is referred to as a position-based method.

[0097] As a prerequisite for this processing, as described above, the reference coordinate system 201 of the robot 10 is associated with the sensor coordinate system 202 representing the position and posture of the sensor 60, so that the position and posture of the sensor 60 being identified by the robot control device 20 can be referenced in sequence from the tool control device 50.

[0098] The control unit 51 sequentially calculates the position of the object O on the reference coordinate system 201 based on the detection position of the object O detected by the sensor 60 and the position and posture of the sensor 60, and controls the servo motor 43 in a manner close to the target position based on the calculated position, so that the position of the tool 30 in the X-axis direction tracks the object O.

[0099] In addition, it is of course possible to perform step S2-1 using controls other than those described above.

[0100] Here, when the position of the object O relative to the sensor 60 changes beyond a predetermined reference (step S1-5), the robot control unit 21 performs an abnormal response operation (step S1-6). Changes exceeding the predetermined reference are large movements of the object O in the image data, movement of the object O in the image data faster than a predetermined speed, disappearance of the object O at an unexpected time, etc. When the power supply is unstable, there is a case where the rotation speed of the motor of the transport device 2 drops sharply, and there is also a case where the rotation speed of the motor changes greatly. In these cases, the position of the object O relative to the sensor 60 changes beyond the above-mentioned predetermined reference.

[0101] As the abnormality handling operation, the robot control unit 21 performs control to stop the operation of sucking the object O, control to avoid the robot 10, control to stop the transport device 2, or control combining these.

[0102] In this embodiment, when the position of the object O relative to the sensor 60 changes beyond a predetermined reference (step S2-3), the control unit 51 also performs an abnormality response operation on the tool side (step S2-4). As the abnormality response operation on the tool side, the control unit 51 performs control to stop the movement of the tool 30, control to move the tool 30 in a direction away from the object O, control to move the tool 30 to a predetermined position, etc.

[0103] Next, the front end of the robot 10 is placed at the target position by the control of steps S1-3 and S1-4 (step S1-7). At this time, when the tool body 32 is placed at the target position by the control of step S2-1 (step S2-5), the adsorption portion 32b of the tool body 32 contacts the upper surface of the object O. When the sensor 32c detects that the adsorption portion 32b is adsorbed on the object O (steps S1-8, S2-6), the control unit 51 ends the tracking control of step S2-1 and moves the tool body 32 to a predetermined position (step S2-7). The robot control unit 21 starts to transport the object O held by the tool 30 to a predetermined position (step S1-9). On the other hand, when adsorption is not detected in step S1-8, the robot control unit 21 moves the robot 10 to the standby position (step S1-10), and the control unit 51 moves the tool body 32 to a predetermined position (step S2-8).

[0104] In addition, in step S2-7, the tool body 32 may not be moved to a predetermined position but may be transported by the robot 10 in consideration of the amount of movement of the tool (step S1-9).

[0105] Thus, the robot system and the robot 10 of the present embodiment include: a sensor 60 for detecting the object O moved by the transport device 2; and a tool 30 mounted on the front end of the arm 12 of the robot 10. The tool moving device 40 is controlled with a tool control cycle shorter than the control cycle of the robot 10, and is used to move the tool body 32 of the tool 30 relative to the robot 10.

[0106] For example, when the object O shakes irregularly on the transport device 2 and the cycle of the change in its motion is shorter than the control cycle of the robot 10, the motion of the robot 10 cannot be coordinated with the object O. Therefore, although the robot 10 can move the tool 30 to the approximate position where the object O is present, the position of the tool 30 cannot be coordinated with the motion of the object O with high precision. In the present embodiment, the tool 30 mounted on the robot 10 is controlled by the control unit 51 and using the tool control cycle, which is shorter than the control cycle of the robot 10. Therefore, without shortening the control cycle of the robot 10, the position of the tool body 32 of the tool 30 can track the object O on the transport device 2 with high precision.

[0107] In addition, in this embodiment, the sensor 60 detects the object O in a cycle shorter than the control cycle of the robot 10, and the robot control device 20 that controls the robot 10 uses the data received sequentially from the sensor 60 and controls the robot 10 in a cycle longer than the tool control cycle.

[0108] Therefore, it is not necessary to generate tool control data and robot control data separately in the sensor 60 , and the control of the robot control device 20 is performed in a control cycle longer than the tool control cycle.

[0109] In addition, in this embodiment, when the position of the object O detected by the sensor 60 changes beyond a predetermined reference, at least one of the robot 10 and the tool 30 performs an abnormal response operation. This structure is advantageous in reliably preventing damage to the robot 10, the tool 30, the transport device 2, the object O, etc.

[0110] Next, a robot system according to a second embodiment of the present invention will be described using the drawings.

[0111] like Figure 5 As shown, the robot system of the second embodiment is different from the first embodiment in the installation position of the sensor 60. Specifically, in the second embodiment, the sensor 60 is fixed to the slider 31 or the tool body 32 of the tool 30, and the sensor 60 is moved together with the tool 30 by the tool moving device 40. Even in the robot system of the second embodiment, the same robot 10, robot control device 20, tool 30, tool moving device 40, tool control device 50, and sensor 60 as those of the first embodiment can be used.

[0112] In the tool control device 50 or the robot control device 20 of the second embodiment, the mounting position and posture of the sensor 60 (sensor coordinate system 202 ) and the position and posture of the tool 30 (tool tip coordinate system 206 ) are previously associated with each other.

[0113] The current position of the sensor 60 viewed from the reference coordinate system 201 of the robot controller 20 can be obtained by taking into account the amount of movement of the tool body 32 .

[0114] Even when the object O is removed in the second embodiment, Figure 4 The flowchart shown in FIG. 2 is used to perform processing of the robot control unit 21 based on the motion program 23b and the tracking control program 23c, and processing of the control unit 51 based on the tracking control program 53b. However, the second tracking control in step S2-1 can be performed using, for example, the following two methods. In this embodiment, the former control is referred to as an image-based method, and the latter control is referred to as a position-based method. Of course, other controls can also be used to perform the processing of step S2-1.

[0115] As a premise for the following two processes, as described above, the tool control device 50 can sequentially calculate the position of the tool body 32 in the reference coordinate system 201 based on the position and posture of the tool body 32 recognized by the robot control device 20 and the amount of movement of the tool body 32. In addition, the tool tip coordinate system 206 representing the position and posture of the tool 30 is associated with the sensor coordinate system 202 representing the position and posture of the sensor 60. That is, the tool control device 50 recognizes the position and posture of the sensor 60 in the reference coordinate system 201.

[0116] In the control based on the image method, the control unit 51 controls the motor 43 to always arrange a specific position such as the center of gravity of the object O at a predetermined position within the field of view of the sensor 60, thereby causing the sensor 60 to track the object O along the X-axis direction. Through this tracking, the tool body 32, which is fixed in position relative to the sensor 60, tracks the object O.

[0117] In the control based on the position method, the control unit 51 calculates the position of the object O on the reference coordinate system 201 in sequence based on the detection position of the object O detected by the sensor 60 and the position and posture of the sensor 60 relative to the tool 30, and tracks the position of the tool 30 in the X-axis direction based on the calculated position.

[0118] Even in the second embodiment, the tool 30 mounted on the robot 10 can be controlled by the control unit 51 using a tool control cycle that is shorter than the control cycle of the robot 10. Therefore, the second embodiment can achieve the same effects as the first embodiment.

[0119] In the second embodiment, the sensor 60 moves together with the tool body 32 of the tool 30, so the position of the tool body 32 relative to the sensor 60 becomes constant. Therefore, the movement of the tool body 32 can be directly detected by the sensor 60, and the position of the object O relative to the sensor 60 is directly associated with the position of the object O relative to the tool body 32. This is advantageous in achieving accurate control, high-speed control, simplification of control, etc.

[0120] Next, a robot system according to a third embodiment of the present invention will be described using the drawings.

[0121] like Figure 6 As shown, the robot system of the third embodiment is different from the first embodiment in the installation position of the sensor 60. Specifically, in the third embodiment, the sensor 60 is fixed at a predetermined position using a bracket, a frame, etc. Even in the robot system of the third embodiment, the robot 10, the robot control device 20, the tool 30, the tool moving device 40, the tool control device 50, and the sensor 60 that are the same as those in the first embodiment can be used.

[0122] In the robot controller 20 of the third embodiment, the reference coordinate system 201 and the position and posture of the sensor 60 (sensor coordinate system 202 ) are associated in advance.

[0123] Even when the object O is removed in the third embodiment, Figure 4 According to the flowchart shown in FIG. 2 , the processing of the robot control unit 21 based on the action program 23b and the tracking control program 23c, and the processing of the control unit 51 based on the tracking control program 53b are performed, but the first tracking control of step S1-3 is a control based on the position method, and in step S1-1, the front end of the robot 10 is arranged at a predetermined position for preparing to take out the object O. In addition, the tracking control in step S2-1 is performed by, for example, the following method. Since the following method is a control based on the detected position of the object O on the reference coordinate system 201, it is called a position-based method in this embodiment. Of course, other controls can also be used to perform the processing of step S2-1.

[0124] As a prerequisite for the following processing, as described above, the reference coordinate system 201 of the robot 10 is associated with the sensor coordinate system 202 indicating the position and posture of the sensor 60. In addition, the tool control device 50 can sequentially calculate the position and posture of the tool body 32 based on the position of the tool 30 observed from the reference coordinate system 201 and the amount of movement of the tool body 32, and associate the position and posture of the tool body 32 with the reference coordinate system 201 in the tool control device 50.

[0125] The control unit 51 sequentially calculates the position of the object O on the reference coordinate system 201 based on the detection position of the object O detected by the sensor 60 and the position and posture of the sensor 60 , and causes the position of the tool body 32 in the X-axis direction to track the calculated position.

[0126] Even in the third embodiment, the tool 30 attached to the robot 10 is controlled by the control unit 51 using the tool control cycle, which is shorter than the control cycle of the robot 10. Therefore, the third embodiment can achieve the same effects as the first embodiment.

[0127] In addition, in the first to third embodiments, the robot control device 20, the tool control device 50, or other computers may perform image processing such as spot processing, pattern matching processing, center of gravity position detection, etc. on the detection results of the sensor 60.

[0128] For example, the sensor 60 sends the image to the robot control device 20 that can process in a long cycle. In the robot control device 20, pattern matching using the outline of the object is performed to detect the accurate position or posture of the object O. The robot control device 20 can control the robot 10 in a manner close to the object O based on the detection result. At this time, the sensor 60 can also receive the detection result, and perform image processing such as spot processing and pattern matching processing, center of gravity position detection, etc. near the detection position of the object O detected in the detection image to obtain sensor data, and send the sensor data to the tool control device 50 that needs to be processed in a short cycle, and the tool control device 50 moves the tool body 32.

[0129] In addition, in the first to third embodiments, the robot control device 20 , the sensor 60 , or other computers or the like may also assume a part or all of the functions of the tool control device 50 .

[0130] Furthermore, in the first to third embodiments, although the work object is used as the detection object, another object whose relative relationship with the work object is kept constant may be used as the detection object.

[0131] In addition, the sensor 60, the robot control device 20 and the tool control device 50 are respectively connected to the upper-level control device, and the detection results, settings, calculation results, etc. of the sensor 60, the robot control device 20 and the tool control device 50 can be sent and received via the upper-level control device.

[0132] In addition, the tool body 32 can be a processing tool for performing predetermined processing such as mechanical processing, a welding tool, a painting tool, a cleaning tool, a measuring tool including a close-up camera and a non-contact thermometer, various sensors, an assembly tool including a nut tightening device, etc., or other well-known tools. The object O can also be various objects such as an assembly operation object part or a processing object part including a vehicle body, a hole set in the vehicle body, a frame, a component, a semi-finished product, food, medical supplies, etc.

[0133] In addition, in the first to third embodiments, the tool body 32 may also have an adsorption portion moving device that uses a motor to move the adsorption portion 32b along the X-axis direction, and the tool control device 50 uses the detection position of the object O detected by the sensor 60 to control the adsorption portion moving device.

[0134] In addition, in the first to third embodiments, when the tool body 32 is a hand holding the object O with a plurality of fingers, the tool control device 50 can also control each finger of the hand using the detected position of the object O detected by the sensor 60. In these cases, even without the tool moving device 40, the same effects as described above can be achieved.

[0135] Furthermore, in the first to third embodiments, among the plurality of arm members constituting the arm 12 of the robot 10, only the flange member 13 (the arm member driven around the final axis) at the most distal end side is enabled to move at high speed, and the same effect is achieved by incorporating the tool control unit 51 in the robot control device 20 and controlling the most distal end arm member with a tool control cycle shorter than the control cycle of the robot 10. In addition, the second arm member from the most distal end side can be controlled in the same manner with the tool control cycle.

[0136] In the first to third embodiments, another robot may be used to move the object O instead of the transport device 2. Even in this case, the same effects as described above can be achieved. Furthermore, when the object O is a car or the like, the object O that performs a predetermined operation, i.e., the vehicle body, may be moved by an engine, wheels, etc. In these cases, the other robot, engine, wheels, etc. function as a moving unit.

[0137] In the first to third embodiments, the object O may be moved by a slide that slides, rolls, or falls due to gravity, instead of the transport device 2. In this case, the inclined slide is vibrated by a vibration excitation device, so that the object O on the slide can be smoothly moved. In these cases, the slide, the vibration excitation device, etc. function as a moving unit, and the object O moved by the slide is taken out by the tool body 32 installed on the robot 10.

[0138] Furthermore, in the first to third embodiments, the tool moving device 40 has an X-axis direction actuator for moving the tool body 32 along the X-axis direction, and the X-axis direction actuator has a motor 43 and a ball screw 42. In this regard, the tool moving device 40 may also have a Y-axis direction actuator that is the same as the X-axis direction actuator, and the tool control device 50 controls the X-axis direction actuator and the Y-axis direction actuator using the detection position of the object O detected by the sensor 60. In this case, the position of the tool body 32 can track the object O with high accuracy along the X-axis direction and the Y-axis direction. The tool moving device 40 may also have a Z-axis direction actuator, a rotation direction actuator, and the like.

Claims

1. A robot system, characterized in that: have: a sensor that acquires data for detecting at least a position of an object moved by a moving unit, the moving unit being used to move the object; A robot equipped with a tool and using the tool to perform a predetermined operation on the object; as well as a control unit that controls a tool moving device, the tool, or an arm member on the front end side of the arm of the robot based on the data and with a tool control cycle shorter than a control cycle of the robot, wherein the tool moving device is used to move the tool relative to the robot, The sensor acquires the data in a cycle shorter than a control cycle of the robot. a robot control device for controlling the robot, controlling the robot to perform a first tracking control for causing the sensor to track the object by using the data sequentially received from the sensor in each cycle longer than the tool control cycle, The control unit controls the tool moving device with the tool control cycle shorter than the control cycle of the robot to perform a second tracking control for causing the tool to track the object. The tool moving device moves the sensor together with the tool.

2. The robot system according to claim 1, characterized in that: When the position of the object detected based on the data changes beyond a predetermined reference, at least one of the robot and the tool performs an abnormality handling operation.

3. A robot, characterized in that: have: an arm having a tool mounted thereon and performing a predetermined operation on an object moved by a moving unit using the tool, the moving unit moving the object; a sensor mounted on the arm or the tool and acquiring data for detecting at least the position of the object moved by the mobile unit; as well as a control unit that controls a tool moving device, the tool, or an arm member on the front end side of the arm based on the data and with a tool control cycle shorter than a control cycle of the robot, wherein the tool moving device is used to move the tool relative to the arm, The sensor acquires the data in a cycle shorter than a control cycle of the robot. a robot control device for controlling the robot, controlling the robot to perform a first tracking control for causing the sensor to track the object by using the data sequentially received from the sensor in each cycle longer than the tool control cycle, The control unit controls the tool moving device with the tool control cycle shorter than the control cycle of the robot to perform a second tracking control for causing the tool to track the object. The tool moving device moves the sensor together with the tool.

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