Robot control system

Abstract

The present invention provides a robot control system. In a robot control system that uses a robot to perform work on a continuously moving work object, a repeatedly moving, or a stopped work object, even if the robot cannot perform the work properly, the situation can be detected and the equipment damage and other problems can be avoided. The robot control system comprises: a robot (4) for performing work on the work object; a control unit for controlling the driving of the robot (4); a first area setting unit for setting a first area (R1) for performing work on the work object; and a second area setting unit for setting a second area (R2) outside the first area (R1) so as to make the robot (4) perform a retreat action as the robot (4) follows the moving work object and a work device (5) provided on the robot (4) leaves the first area (R1) and enters the second area (R2).

Description

Technical Field

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

[0002] Conventionally, when an industrial robot is used to perform work on a work object such as an article conveyed through a production line, it is important to control the driving and stopping (stop position) of the robot with high precision with respect to the conveyed work object.

[0003] For example, Patent Document 1 discloses “a robot device for gripping an object that is in relative motion, the robot device comprising: a gripping unit having a gripping mechanism for gripping the object, and the gripping mechanism being configured to be movable; an imaging unit that is fixed in a manner capable of moving together with the gripping mechanism of the gripping unit and captures the object; a feature extraction unit that extracts coordinates of one or more feature quantities from an image of the object captured by the imaging unit; a storage unit that stores the position of the gripping mechanism when the gripping mechanism grips the object as a first fingertip position, stores the position of the gripping mechanism when the gripping mechanism is caused to move within a range where the gripping mechanism releases the object and the imaging unit can capture the object as a second fingertip position, and stores The invention further comprises a method for controlling the holding mechanism to track the moving object by moving the holding mechanism, wherein the holding mechanism is configured to: store the coordinates of each feature quantity of the object extracted by the feature quantity extraction unit after the camera unit shoots the object at the second fingertip position; a calculation unit, which calculates a movement matrix for moving from the second fingertip position to the first fingertip position; a tracking control unit, which moves the holding mechanism so that the coordinates of each feature quantity of the moving object extracted by the feature quantity extraction unit are consistent with the coordinates of each feature quantity stored in the storage unit, thereby controlling the holding mechanism to track the moving object; and a holding control unit, which, when the holding mechanism tracks the moving object, moves the holding mechanism close to the moving object based on the movement matrix calculated by the calculation unit and controls the holding unit to hold the object.

[0004] Patent document 2 discloses "a robot control method for tracking a moving object transported by a transport device and causing the moving object to perform a specified movement, the robot control method being characterized in that the moving object is detected and the position of the moving object in the coordinate system of the transport device is obtained based on the detection result, the position of the moving object is continuously updated in the coordinate system of the transport device based on the position and the movement amount of the transport device, the position of the moving object is transformed from the coordinate system of the transport device to the coordinate system of the robot, thereby generating a trajectory of the robot for tracking the moving object."

[0005] In addition, the inventor of the present application has invented a robot control system for controlling a robot with high precision so that it can accurately follow an object, etc., the robot control system comprising: one or more visual sensors, which are arranged on the arms of the robot; a storage unit, which stores a first feature quantity related to at least the position and posture of the following object as target data for the visual sensor to follow the following object; a feature quantity detection unit, which uses an image obtained by the visual sensor to detect a second feature quantity related to at least the position and posture of the following object; a movement quantity calculation unit, which calculates a movement instruction of the arm based on the difference between the second feature quantity and the first feature quantity; and a movement instruction unit, which moves the arm based on the movement instruction, and the applicant of the present application has applied for a patent for this invention (Japanese Patent Application No. 2019-010335).

[0006] Prior art literature

[0007] Patent Literature

[0008] Patent Document 1: Japanese Patent Application Publication No. 2002-018754

[0009] Patent Document 2: Japanese Patent Application Publication No. 2002-192486 Summary of the invention

[0010] Problem that the invention aims to solve

[0011] On the other hand, if the robot performs work while following the article moved by the conveyor, it may not be able to complete the work in time.

[0012] For example, when a robot is assembling doors on a car body moving through a production line, pins need to be inserted to install the door in a way that it can be opened. At this time, if the pins are not well embedded or get stuck, the robot will not be able to complete the work in time, which may cause damage to the equipment.

[0013] Therefore, for robot control systems that use robots to perform work on continuously moving work objects or work objects that move and stop repeatedly, there is a strong desire to develop a method or means that can detect the situation and avoid problems such as equipment damage even if the robot cannot perform the work properly.

[0014] Solutions for solving problems

[0015] One mode of the robot control system disclosed in the present invention is configured to include: a robot, which is used to perform work on a work object; a control unit, which controls the drive of the robot; a first area setting unit, which sets a first area for performing work on the work object; and a second area setting unit, which sets a second area outside the first area, for causing the robot to perform a retreat action as the robot follows the moving work object and the working device provided on the robot leaves the first area and enters the second area.

[0016] Effects of the Invention

[0017] According to one aspect of the robot control system of the present disclosure, as the working device of the robot leaves the first area where work is safely performed on a work object and enters the second area, the control unit controls the driving of the robot to perform a retreat operation.

[0018] Therefore, for a robot control system that uses a robot to perform work on a continuously moving work object or a work object that repeatedly moves and stops, even if the work cannot be properly performed due to an unforeseen situation, the situation can be detected and damage to the equipment can be avoided. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a perspective view showing one embodiment of a robot control system.

[0020] Figure 2 This is a diagram showing an example of a first area, a second area, and a movable area set by a robot control system of one embodiment.

[0021] Figure 3 This is a diagram showing an example of a first area, a second area, and a third area set by a robot control system of one embodiment.

[0022] Figure 4 This is a diagram showing an example of a first area and a second area set by a robot control system of one embodiment.

[0023] Description of Reference Numerals

[0024] 1: Robot control system; 2: Work object; 4: Robot; 5: Tool (work device); R1: Work area (first area); R2: Avoidance area (second area); R3: Work restart area (third area); R4: Movable area. DETAILED DESCRIPTION

[0025] Below, refer to Figures 1 to 4 A robot control system according to one embodiment will be described.

[0026] The robot control system of the present embodiment is related to a system for controlling a robot (industrial robot) that is installed in a production line or the like and performs work on a work object such as a conveyed article.

[0027] Specifically, if Figure 1 As shown, the robot control system 1 of this embodiment is configured to include: a robot 4 for performing work such as assembling a door 3 on a work object 2 such as a car body (not shown); and a control unit for controlling the driving of the robot 4 .

[0028] The robot 4 is configured in a multi-jointed shape, for example, and includes one or more visual sensors provided on a movable arm, and a tool (working device) 5 attached to the arm for performing a predetermined work on the work object 2 .

[0029] The control unit controls the driving of the robot 4 to perform work on the work object 2 , and controls the driving of the robot 4 based on the detection result of the visual sensor so that the tool 5 , an object held by the tool 5 , etc. follow the work object 2 .

[0030] like Figure 2 As shown, the robot control system 1 of the present embodiment includes, in addition to the robot 4 and the control unit: an arm position confirmation unit, which continuously confirms the position of the arm; a first area setting unit, which sets a first area R1 for performing work on the work object 2 as a work area; and a second area setting unit, which sets a second area R2 outside the first area R1 where the arm can move safely as an avoidance area, which is used to make the robot 4 retreat as the tool 5 provided on the robot 4 leaves the first area R1 as the work area and enters the second area R2 as the avoidance area as the robot 4 follows the work object 2 moved by a conveying device, etc.

[0031] Here, the positions and sizes of the first region R1 as the work area and the second region R2 as the avoidance area are set according to the content of the work, the moving direction of the work object 2, the structure of the robot 4, and the like.

[0032] The second region R2 as the avoidance region is a region sufficient for the robot 4 to perform an evacuation action, and the tool 5 of the robot 4 performs an evacuation action in the second region R2.

[0033] exist Figure 2 In the example shown, a movable area R4 in which the tool 5 of the robot 4 can move is set as a large area, a first area (working area) R1 as a small area in which the robot 4 can actually work is set inside the movable area R4, and a second area (avoidance area) R2 as a medium area is set in a manner that includes the first area R1 as the working area.

[0034] exist Figure 3 In the example shown, the remaining portion after the rectangular first region R1 as the working area is hollowed out from the rectangular region formed by the outer periphery of the second region R2 as the avoidance region is the second region R2 as the avoidance region.

[0035] exist Figure 4 In the example shown, in consideration of the moving direction of the work object 2, a second region R2 as an avoidance region is provided downstream in the moving direction of a rectangular parallelepiped first region R1 as a work area.

[0036] The arm position confirmation unit is configured using appropriate means such as sensors and image acquisition.

[0037] The robot control system 1 of the present embodiment includes an abnormality processing unit that determines that an abnormality has occurred and performs abnormality processing when the tool 5 of the robot 4 leaves the first region R1 that is a working region.

[0038] In this embodiment, as an abnormality process, the abnormality process unit notifies the operator when the tool 5 of the robot 4 leaves the first area R1 as the working area, so as to make the operator aware of the occurrence of the abnormality or to cause the control unit to perform drive control for the abnormality process.

[0039] For example, as the tool 5 of the robot 4 leaves the first area R1 serving as the working area and enters the second area R2 serving as the avoidance area, the abnormal processing unit stops the movement of the working object 2 or reduces the moving speed of the working object 2 to a specified speed, or causes the robot 4 to perform an evasive action while following the working object 2 which continues to move.

[0040] In addition, preferably, the robot control system 1 of the present embodiment has a third area setting unit, which sets the third area R3 as the work restart area inside the first area R1 as the work area, and the abnormal processing unit is configured such that when the tool 5 leaves the first area R1 as the work area and enters the second area R2 as the avoidance area, the abnormal processing unit continues to judge it as abnormal until the tool 5 enters the third area R3 as the work restart area.

[0041] In the robot control system 1 of the present embodiment constructed as described above, for example, in an operation in which the robot 4 is used to assemble a door 3 of an automobile body as an operation object 2 that is continuously moved by a conveying device, if a tool 5 pin is not well embedded or becomes stuck, and the robot 4 fails to complete the operation in time and leaves the first area R1 as the operation area, the robot 4 is controlled to retreat as the tool 5 enters the second area R2 as the avoidance area.

[0042] At this time, the abnormal processing unit makes the robot 4 continue to follow the continuously moving work object 2 while performing an evasive action, or stops the movement of the work object 2 or reduces the moving speed of the work object 2 to a specified speed, so that the robot 4 can appropriately perform an evasive action.

[0043] That is, mainly, 1) as the tool 5 leaves the first area R1 as the working area, a certain signal is sent to stop the conveying device and continue the work, or, 2) a second area R2 is set as an avoidance area so that the conveying device can perform feedforward and retreat actions without stopping.

[0044] Furthermore, the time required for the retreat operation with a certain margin is calculated based on the moving speed of the work object 2 and the like, and the size of the second region R2 as the avoidance region is determined based on the time.

[0045] Therefore, in the robot control system 1 of the present embodiment, as the tool (working device) 5 of the robot 4 leaves the first area R1 serving as the working area for safely performing work on the work object 2 and enters the second area R2 serving as the avoidance area, the control unit controls the drive of the robot 4 to perform an evasive action.

[0046] Therefore, according to the robot control system 1 of this embodiment, in a robot control system that enables the robot 4 to perform work on a work object 2 that moves continuously or repeatedly moves / stops, even if the work cannot be properly performed due to unforeseen circumstances, the situation can be detected and damage to the equipment can be avoided.

[0047] Here, when the work object 2 moves freely and the retreat action of the robot 4 is complicated, the tool 5 that once left the first area R1 as the work area and appeared in the second area R2 as the avoidance area may move back and forth between the second area R2 and the first area R1. If the normal work action and the abnormal action are switched every time in response to such back and forth movement between the areas R1 and R2, the control becomes complicated and the efficiency is significantly reduced.

[0048] In this regard, in the robot control system 1 of the present embodiment, a third area R3 as a work restart area is set inside the first area R1 as a work area. Thus, when leaving the first area R1 as the work area and entering the second area R2 as the avoidance area, the abnormal processing unit continues to judge as abnormal until entering the third area R3 as the work restart area. Therefore, the normal work action and the abnormal action are not switched every time in response to the back and forth movement between the second area R2 and the first area R1, and the problem of complicated control and significant reduction in efficiency can be eliminated.

[0049] An embodiment of the robot control system has been described above, but the present invention is not limited to the above-described embodiment and can be modified appropriately within a scope not departing from the gist of the present invention.

Claims

1. A robot control system comprising: A robot for performing work on a work object, wherein the work object moves relative to the robot; A control unit that controls driving of the robot; A first area setting unit, which sets a first area for performing work on the work object; as well as a second region setting unit for setting a second region outside the first region; The control unit controls the robot to perform a retreat action as the robot follows the moving work object and a work device provided on the robot leaves the first area and enters the second area.

2. The robot control system according to claim 1, comprising: The abnormality processing unit determines that an abnormality occurs and performs abnormality processing when the working device of the robot leaves the first area.

3. The robot control system according to claim 2, wherein: The abnormality processing unit issues a notification as the working device of the robot leaves the first area.

4. The robot control system according to claim 2, wherein: As the working device of the robot leaves the first area and enters the second area, the abnormality processing unit stops the movement of the working object or reduces the moving speed of the working object to a predetermined speed.

5. The robot control system according to claim 3, wherein: As the working device of the robot leaves the first area and enters the second area, the abnormality processing unit stops the movement of the working object or reduces the moving speed of the working object to a predetermined speed.

6. The robot control system according to claim 2, wherein: When the working device of the robot leaves the first area and enters the second area, the abnormality processing unit causes the robot to perform a retreat operation while continuing to follow the work object that continues to move.

7. The robot control system according to claim 3, wherein: When the working device of the robot leaves the first area and enters the second area, the abnormality processing unit causes the robot to perform a retreat operation while continuing to follow the work object that continues to move.

8. The robot control system according to any one of claims 2 to 7, wherein: further comprising a third region setting unit, the third region setting unit setting a third region inside the first region, When leaving the first area and entering the second area, the abnormality processing unit continues to determine that the abnormality occurs until entering the third area.

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