Working robot system and working robot

Abstract

The present invention provides a working robot system and a working robot, wherein the working robot system comprises: a working robot (10) and a working robot control unit (20), wherein the working robot (10) and the working robot control unit (20) perform work on an object part (101) of an article (100) transported by a transport device (2); a sensor (50) which is arranged at a predetermined position and is used to detect the position of a detection object (O) of the article (100) transported by the transport device (2); and a force detection unit (32) which is used when force control is performed, wherein the working robot control unit (20) controls the working robot (10) based on the detection result of the sensor (50) when the working robot (10) is used to perform work, and simultaneously performs force control.

Description

Technical Field

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

[0002] In the past, when assembling parts to an object being transported by a transport device, the transport device was often stopped. In particular, when assembling parts precisely to a large object such as a vehicle body, it was necessary to stop the transport device from transporting the object. This sometimes resulted in a decrease in operating efficiency.

[0003] On the other hand, a production line is known, which includes: a robot; a transport device that transports an object; a track that is provided along the transport device; and a moving device that moves the robot along the track (for example, see Patent Document 1). In this production line, when the transport device transports the object, the robot performs defect inspection and grinding of the object. In addition, when performing defect inspection and grinding, the moving device moves the robot along the track at the same speed as the transport speed of the object transported by the transport device.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Laid-Open No. 08-72764 Summary of the invention

[0007] Problem that the invention aims to solve

[0008] In the production system, only defect inspection and grinding are performed. On the other hand, when performing operations in which the robot and an object may interfere with each other, force control of the robot is required to prevent damage to the robot, the transport device, and the object. However, there is a possibility that the object moved by the transport device may perform unpredictable actions. Therefore, if the control cycle of the force control is extremely shortened or the sensitivity is not increased, it is difficult to prevent the above-mentioned damage.

[0009] However, the robot can only react within the robot's control cycle, so as a result, the control cycle of force control cannot be shorter than the robot's control cycle. In other words, there is a situation where it is difficult to prevent the above-mentioned damage unless the performance of the robot itself is changed. In addition, if the sensitivity of force control is increased, the possibility of robot oscillation increases. In addition, in the case of an object performing unpredictable movements, even if force control is performed during several consecutive control cycles, the state of contact between the robot and the object cannot be improved. Even in this case, the possibility of robot oscillation increases.

[0010] The present invention has been made in view of the above circumstances. One object of the present invention is to provide a working robot system and a working robot that can effectively prevent damage to a robot, a transport device, an article, and the like.

[0011] Solutions for solving problems

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

[0013] The working robot system of the first scheme of the present invention comprises: a transport device that transports articles; a working robot that performs a predetermined operation on an object part of the article transported by the transport device; a working robot control unit that controls the working robot; a sensor that is arranged at a predetermined position and is used to detect the position of the object part in the article transported by the transport device or a detection object whose position does not change relative to the object part; and a force detection unit that detects the force generated by the contact between a part or tool supported by the working robot and the article. When the working robot is used to perform the predetermined operation, the working robot control unit controls the working robot based on the detected position of the object part or the detection object, and performs force control based on the detection value of the force detection unit.

[0014] In the above scheme, the sensor is arranged at a predetermined position to detect the position of the object part or the detection object in the article. And, the position of the object part or the detection object detected in this way is used to control the working robot. Therefore, even in the state without force control, the working robot control unit can identify the positional relationship between the parts or tools supported by the working robot and the article, and can also identify whether the two are in contact. For example, even in the state without force control, the working robot control unit can identify the abnormality of the conveying device that makes a large change in the movement amount of the article conveyed by the conveying device. Therefore, there is no need to excessively shorten the control cycle of the force control, and it is possible to prevent the working robot, the conveying device, and the article from being damaged, and also control the occurrence of oscillation of the working robot.

[0015] Here, there is also the following idea: the sensor is supported by the front end of the working robot, or the front end of a robot different from the working robot, and when the robot changes the position and posture of the sensor according to the transportation by the transportation device, the accuracy of detecting the position of the object part using the detection data of the sensor is improved. However, if the sensor is supported by the front end of the robot, the position and posture of the sensor may not be completely accurate due to the accuracy of the calibration of the robot, the influence of the deflection of the robot, the absolute accuracy of the robot, etc. In contrast, in this embodiment, the sensor is configured at a predetermined position. Therefore, compared with the case where the sensor is supported by the front end of the robot, the accuracy of detecting the position of the object part using the detection data of the sensor is improved.

[0016] In addition, when the sensor is supported on the front end of the working robot together with the parts or tools, there is a case where the detection range of the sensor is blocked by the parts or tools. When the parts or tools are in contact with the object, there is also a case where the sensor cannot detect the object part or its vicinity. In the above scheme, the sensor is not supported on the working robot. Therefore, the possibility of the detection range of the sensor being blocked by the parts or tools is reduced.

[0017] In addition, when the sensor is supported on the front end of the working robot together with the parts or tools, the sensor needs to be removed from the working robot when cleaning or repairing the tool or the working robot. In this case, when the sensor is reinstalled on the working robot, the sensor needs to be calibrated. In the above scheme, since the sensor is supported on the working robot, the time and labor for calibrating the sensor can be reduced or eliminated.

[0018] In the above scheme, preferably, the working robot control unit uses the detection result of the sensor to make the part or the tool supported by the working robot follow the object part, and at the same time uses the detection value of the force detection unit to perform the force control.

[0019] In this way, by using the detection results of the sensor, the working robot control unit makes the parts or tools of the working robot follow the target part. Therefore, when the working robot performs a predetermined operation, the working robot control unit can accurately control the position and posture of the parts or tools supported by the working robot for the target part of the article transported by the transport device. This is beneficial for preventing damage to the working robot, the transport device, and the article without shortening the control cycle of the force sense control or increasing the sensitivity, and is also beneficial for suppressing the occurrence of oscillation of the working robot.

[0020] In the above scheme, preferably, the working robot system has a detection unit for detecting at least the position of the article on the transport device, and the working robot control unit makes the part or the tool of the working robot approach the object part based on the detection result of the detection unit. In addition, when approaching, the working robot can also change the posture of the part or the tool according to the posture of the object part.

[0021] When the working robot performs work in this manner based on the detection result of the detection unit, the efficiency of the work is improved.

[0022] In the above aspect, preferably, when the detection position of the target portion or the detection object changes beyond a predetermined reference, at least one of the working robot control portion and the transport device performs an abnormality response operation.

[0023] In this scheme, in the state where the positional relationship between the parts or tools supported by the working robot and the article is identified as described above, at least one of the working robot control unit and the transport device also performs abnormal response work based on the detection result of the sensor. This structure is advantageous in effectively preventing the working robot, the transport device, and the article from being damaged, and is also advantageous in suppressing the occurrence of vibration of the working robot.

[0024] A second embodiment of the present invention is a working robot comprising: an arm that performs a predetermined operation on an object part of an article being transported by a transport device; a working robot control unit that controls the arm; and a force detection unit that detects a force generated by contact between a part or tool supported by the arm and the article, the working robot control unit receiving data about the position from a measuring device having a sensor for detecting a position, the position being the object part moved by the transport device or the position of a detection object whose position does not change relative to the object part, and when the arm is used to perform the predetermined operation, the working robot control unit controls the arm using the data about the position and performs force control based on the detection value of the force detection unit.

[0025] Effects of the Invention

[0026] According to the present invention, it is possible to effectively prevent a robot, a transport device, an article, or the like from being damaged. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a diagram showing the configuration of a working robot system according to one embodiment of the present invention.

[0028] Figure 2 This is a block diagram of a working robot control device of the working robot system according to the present embodiment.

[0029] Figure 3 This is an example of image data captured by the sensor of the measurement robot system according to the present embodiment.

[0030] Figure 4 It is a diagram showing another example of the configuration of the control system according to the present embodiment.

[0031] Figure 5 This is a flowchart showing an example of processing by the control device of the working robot and the measuring device according to the present embodiment.

[0032] Figure 6 It is a top view of the object portion and the mounting portion of the component of the article of this embodiment.

[0033] Figure 7 It is a diagram for explaining the coordinate system of the tracking control in the working robot system according to the present embodiment.

[0034] Figure 8 It is a diagram showing the structure of a modified example of the working robot system according to the present embodiment.

[0035] Description of reference numerals:

[0036] 2: Transport device

[0037] 2a: Motor

[0038] 3: Roller

[0039] 10: Operational Robot

[0040] 10a: Arm

[0041] 11: Servo motor

[0042] 20: Operation robot control device

[0043] 21: Operation robot control unit

[0044] 22: Display device

[0045] 23: Storage

[0046] 23a: System Programs

[0047] 23b: Operation Procedure

[0048] 23c: Force control program

[0049] 23d: Measurement Program

[0050] 30: Hand

[0051] 32: Force sensor (force detection unit)

[0052] 40: Detection device (detection unit)

[0053] 50: Sensor

[0054] 60: Measuring device

[0055] 63: Track

[0056] 64: Slider

[0057] 65: Servo motor

[0058] 100: Items

[0059] 101: Object Department

[0060] 101a: Hole

[0061] 110: Parts

[0062] 111: Installation

[0063] 111a: Axis DETAILED DESCRIPTION

[0064] Hereinafter, a working robot system according to a first embodiment of the present invention will be described using the drawings.

[0065] like Figure 1 As shown, the working robot system of this embodiment includes: a transport device 2, which transports an object 100 as a work object; a working robot 10, which performs a predetermined work on an object part 101 of the object 100 transported by the transport device 2; a working robot control device 20, which has the working robot 10; and a detection device 40 as a detection unit.

[0066] The detection device 40 detects that the article 100 has been transported to a predetermined position. The detection device 40 can also obtain data that can identify the position and posture of the object portion 101 of the article 100 transported by the transport device 2. As the detection device 40, all devices having such a function can be used. In this embodiment, the detection device 40 is a photoelectric sensor. In this case, the detection device 40 detects that the article 100 has been transported to its set position. The detection result of the detection device 40 can be sent to each control device or to the upper-level control device 80 described below.

[0067] The article 100 is not limited to a specific type, but in this embodiment, as an example, the article 100 is a vehicle body. The conveying device 2 conveys the article 100 by driving a plurality of rollers 3 using a motor 2a. In this embodiment, the conveying device 2 is directed toward Figure 1The right side of the conveying object 100 in the working robot 2a is also provided with a working position detection device 2b. The working position detection device 2b detects the rotation position and the rotation amount of the output shaft of the motor 2a in sequence. The working position detection device 2b is, for example, an encoder, and the detection value of the working position detection device 2b is sent to the working robot control device 20.

[0068] The object part 101 is a portion of the article 100 on which the working robot 10 performs a predetermined operation. In the present embodiment, as the predetermined operation, the hand 30 of the working robot 10 lifts the part 110, and the working robot 10 mounts the mounting part 111 of the part 110 on the object part 101. Thus, for example, the shaft 111a extending downward from the mounting part 111 of the part 110 is fitted into the hole 101a provided in the object part 101 of the article 100.

[0069] Furthermore, in a state where the article 100 is moved by the transport device 2 , the working robot 10 attaches the attachment portion 111 of the component 110 to the target portion 101 .

[0070] The working robot 10 is not limited to a specific type of robot, but the working robot 10 of the present embodiment includes a plurality of servomotors 11 (see Figure 2 ). In addition, the arm 10a of the working 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. As an example, the working position detection device is an encoder. The detection value of the working position detection device is sent to the working robot control device 20.

[0071] The hand 30 is attached to the front end of the arm 10a of the working robot 10. The hand 30 of the present embodiment supports the component 110 by gripping with a plurality of claws, but a hand that supports the component 110 by magnetic force, air attraction, or a combination thereof may be used.

[0072] The hand 30 includes a servo motor 31 for driving the claw (see Figure 2 The servo motor 31 has a working position detection device for detecting its working position. As an example, the working position detection device is an encoder. The detection value of the working position detection device is sent to the working robot control device 20.

[0073] In addition, various servo motors such as a rotary motor and a linear motor can be used as the servo motors 11 and 31 .

[0074] A force sensor 32 as a force detection unit is mounted on the front end of the arm 10a of the working robot 10. The force sensor 32 detects, for example, Figure 1The force sensor coordinate system 202 is shown to detect forces in the x-axis direction, the y-axis direction, and the z-axis direction, and also detects forces around the x-axis, around the y-axis, and around the z-axis.

[0075] In this embodiment, 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 the reference coordinate system 201, so that the vertical direction is consistent with that of the reference coordinate system 201. Figure 1 The Z-axis direction is consistent, so Figure 1 The Y-axis direction of the conveying device 2 is consistent with the width direction of the conveying device 2.

[0076] The force sensor 32 can detect the direction and degree of force applied to the hand 30 or the part 110 held by the hand 30. Therefore, in the present embodiment, the force sensor 32 is disposed between the working robot 10 and the hand 30, but the force sensor 32 may be disposed in either the hand 30 or the working robot 10.

[0077] like Figure 2 As shown, the working robot control device 20 includes: a working robot control unit 21, which has a CPU, RAM, etc.; a display device 22; a storage unit 23, which has a non-volatile memory, ROM, etc.; a plurality of servo controllers 24, which correspond to the servo motors 11 of the working robot 10 respectively; a servo controller 25, which corresponds to the servo motor 31 of the hand 30; and an input unit 26 connected to the working robot control device 20. That is, the working robot control device 20 controls the arm 10a and the hand 30 of the working robot 10. In one example, the input unit 26 is an input device such as an operating panel that can be carried by an operator. There is also a case where the input unit 26 performs wireless communication with the working robot control device 20.

[0078] like Figure 1 As shown, the working robot system of this embodiment includes a plurality of measuring devices 60. Each measuring device 60 has a sensor 50. In this embodiment, two measuring devices 60 are used. Alternatively, there may be only one measuring device 60.

[0079] The sensors 50 of the plurality of measuring devices 60 are respectively arranged at predetermined positions. Figure 1 As shown, the sensors 50 of the two measuring devices 60 are arranged at intervals in the X-axis direction, and the two sensors 50 are respectively positioned at predetermined positions by a bracket 51 or a frame 52. The sensor 50 supported by the bracket 51 is arranged on the side of the object 100, and the sensor 50 supported by the frame 52 is arranged above the object 100.

[0080] The sensor 50 is a two-dimensional camera, a three-dimensional camera, a three-dimensional distance sensor, etc. The sensor 50 of this embodiment is a two-dimensional camera, and each sensor 50 sequentially sends image data to the working robot control device 20. As described below, the working robot control unit 21 can detect the position and posture of the detection object O in the image data.

[0081] When setting the reference coordinate system 201, the setting tool provided at the front end of the working robot 10 touches a plurality of predetermined positions of a calibration fixture provided at a certain position on the transport device 2. In this way, the reference coordinate system 201 is set. In this embodiment, the directions in which the X-axis, Y-axis, and Z-axis of the reference coordinate system 201 extend are the same as those in the embodiment of the present invention. Figure 1 The directions in which the X-axis, Y-axis, and Z-axis shown extend coincide with each other, and the position of the reference coordinate system 201, that is, the origin position, becomes a predetermined position on the calibration jig.

[0082] In addition, the calibration jig is installed at a known position of the working robot and before it is moved to the two sensors 50, the two sensors 50 respectively acquire image data of the calibration jig, and the reference coordinate system 201 of the working robot 10 is associated with the position and posture (sensor coordinate systems 203, 204) of the sensors 50. Alternatively, the calibration jig is set at a known position visible from the two sensors 50, and the two sensors 50 respectively acquire image data of the calibration jig, thereby associating the reference coordinate system 201 of the working robot 10 with the position and posture (sensor coordinate systems 203, 204) of the sensors 50.

[0083] Furthermore, when setting the reference coordinate system, a jig different from the calibration jig can be used.

[0084] The storage unit 23 of the working robot control device 20 stores a system program 23a, which performs basic functions of the working robot control device 20. The storage unit 23 stores a working motion program 23b. The storage unit 23 stores a force sense control program 23 and a measurement program 23d.

[0085] The working robot control unit 21 monitors the position or movement amount of the object part 101 using the detection data of the sensor 50 based on the programs 23a and 23d. In addition, the working robot control unit 21 sends a control command for performing a predetermined operation on the object 100 to each servo controller 24 and 25 based on the programs 23a, 23b, and 23c. As a result, the working robot 10 and the hand 30 perform a predetermined operation on the object 100.

[0086] In addition, if Figure 4As shown, the working robot control device 20 and each measuring device 60 can also be connected to the upper-level control device 80. The upper-level control device 80 is a computer having a processor, a storage unit such as RAM or a hard disk, an input unit, and a transceiver unit. The operating state of the working robot 10, the operating state of each measuring device 60, etc. are sent to the upper-level control device 80. The data of the position and movement amount of the object part 101 monitored by the sensor 50 and the measuring control device 70, and the following data about these data are also sent to the upper-level control device 80 in sequence. In addition, the data are sent from the upper-level control device 80 to the working robot control device 20 in sequence. In addition, other data received by the upper-level control device 80 are also sent from the upper-level control device 80 to the working robot control device 20.

[0087] In addition, when the upper-level control device 80 does not exist, the respective control devices are directly exchanged.

[0088] Reference Figure 5 The flowchart of FIG. 1 will be used to explain the processing of the working robot control unit 21 when the working robot 10 performs a predetermined operation on the object 100. In addition, the following control is performed in a state where the article 100 is being transported by the transport device 2.

[0089] First, when receiving a detection signal of the object 100 from the detection device 40 (step S1-1), the working robot control unit 21 sends a control instruction for bringing the part 110 held by the hand 30 close to the target part 101 to each servo controller 24 based on the working action program 23b (step S1-2).

[0090] In order to perform the control of step S1-2, the working robot control unit 21 uses data of the position of the robot relative to the object portion 101 in the article 100 and the detection object O. In addition, the position of the robot can be corrected using the pre-specified approximate conveying speed of the conveying device 2, or the conveying speed of the conveying device 2 obtained by the working position detection device 2b.

[0091] In addition, the working robot control unit 21 starts processing the detection data of the sensor 50 based on the measurement program 23d (step S1-3). In this embodiment, the detection objects O are prepared for the two sensors 50, one of which is a mark set on the side of the object 100, and the other is a mark set on the upper surface of the object 100 ( Figure 1 ).

[0092] The position and posture of the detection object O relative to the target unit 101 only need not change.

[0093] Next, if there is a detection object within the field of view of the sensor 50 (step S1-4), the working robot control unit 21, based on the measurement program 23d, performs as a first processing, the export of correction data of the position coordinates and posture of the object part 101 based on the measurement of the detection object O, and the correction of the working action program 23b using the correction data (step S1-5). At the same time or immediately after the first processing, as a second processing, the control for detecting the position and moving speed of the detection object O is started (step S1-6), or the control for the movement of the reference coordinate system 201 is started (step S1-7).

[0094] First treatment

[0095] The working robot control unit 21 detects the position, or the position and posture, of the detection object O in the reference coordinate system 201 using the image data of the sensor 50. The working robot control unit 21 obtains the correction data of the first processing based on the relative relationship between the previously taught reference and the actual detection result. Since the position and posture of each detection object O do not change relative to the object unit 101, the correction data can be used as the correction data of the object unit 101.

[0096] The working robot control unit 21 uses the obtained position coordinates and posture correction data to correct the working motion program 23b. In addition, it is possible to correct only the position coordinates or only the posture. Thus, when the shaft 111a of the part 110 supported by the hand 30 is fitted into the hole 101a of the object part 101 through the following control ( Figure 6 ), which can improve the accuracy of the fitting.

[0097] Second treatment

[0098] As the second processing, in order to perform steps S1-6 and S1-7, for example, the following control can be used. In the present embodiment, the following control is referred to as a position-based method. Of course, steps S1-6 and S1-7 can also be performed using other controls. In the present embodiment, in the following control, the position of the detection object O is detected based on the detection data of the sensor 50, but the position and posture of the detection object O can also be detected based on the detection data of the sensor 50.

[0099] The control based on the position method is to sequentially detect the position of the characteristic shape and / or characteristic point of the article 100 on the fixed reference coordinate system 201 using the image data sequentially acquired as the detection data of the sensor 50. In the present embodiment, the position of the object part 101 of the article 100 is sequentially detected based on the detection result of the position of the detection object O whose position and posture do not change relative to the object part 101. In addition, the posture of the object part 101 can also be sequentially detected at the same time. Moreover, the working robot control unit 21 sequentially moves the reference coordinate system 201 based on the difference between the detection positions that move with the passage of time on the reference coordinate system 201 (for example, the difference between the current detection position and the detection position at a certain time in the past).

[0100] Here, in the first processing, in order to detect the position of the detection object O entering the detection range of the sensor 50, it is necessary to perform image processing on the entire area of ​​the detection range, but in the second processing, the general position of the detection object O can be specifically identified, so image processing is performed on a part of the detection range, thereby achieving an improvement in processing speed.

[0101] In the present embodiment, when the control based on the position method is performed, the detection object O is always arranged within the field of view of the sensor 50 .

[0102] Furthermore, when the detection object O moves in the X-axis direction and the Y-axis direction as viewed from the sensor 50 disposed above the object 100, the reference coordinate system 201 also moves in the X-axis direction and the Y-axis direction. When the detection object O moves in the X-axis direction and the Z-axis direction as viewed from the sensor 50 disposed on the side of the object 100, the reference coordinate system 201 also moves in the X-axis direction and the Z-axis direction. Furthermore, when the positions of the two detection objects O rotate around axes extending in the Z-axis direction, the Y-axis direction, etc., the posture of the reference coordinate system 201 also rotates around these axes.

[0103] In this way, when the setting position of the reference coordinate system 201, for example, the origin position, is sequentially moved as the position of the detection object O moves, the working robot control unit 21 can control the working robot 10 without correcting the working operation program 23 b.

[0104] In the above control, the working robot control unit 21, for example, Figure 7 As shown in FIG. 1 , when the positions p11 and p21 of the two detection objects O move to the positions p12, p22, ..., respectively, fitting is performed using the least square method or the like to calculate the moving speeds of the two detection objects O. Alternatively, the moving speeds of the two detection objects O are averaged to calculate the average moving speed. The value obtained by multiplying the moving speed by the time becomes the moving amount.

[0105] The set position for moving the reference coordinate system 201 can also be interpolated using the movement amount.

[0106] In addition, the center positions of the two detection objects O in the reference coordinate system 201 can also be used as the detection positions of the two detection objects O. When there are three or more detection objects O, the center of gravity positions of the three or more detection objects O can be used as the detection positions of these detection objects O. By using the center positions or center of gravity positions of multiple detection objects O, the influence of the detection error of the object 100 can be reduced.

[0107] Then, the working robot control unit 21 starts sending control commands for fitting the shaft 111 a of the component 110 into the hole 101 a of the target unit 101 to each servo controller 24 based on the working operation program 23 b (step S1 - 8 ).

[0108] Here, the work motion program 23 b of the present embodiment sequentially changes the position and posture of the axis 111 a of the component 110 in the reference coordinate system 201 .

[0109] The setting position of the reference coordinate system 201 is sequentially adjusted based on the detection result of the sensor 50 . In this control, the target portion 101 of the article 100 is moved by the conveying device 2 , but the target portion 101 is stationary when viewed from the reference coordinate system 201 .

[0110] In such a controlled state, the working robot control unit 21 starts force sense control based on the force sense control program 23c (step S1-9). As force sense control, well-known force sense control can be used. In this embodiment, the working robot 10 moves the part 110 in a direction away from the force detected by the force sensor 32. The amount of movement is determined by the working robot control unit 21 based on the detection value of the force sensor 32.

[0111] For example, when the axis 111a of the part 110 held by the hand 30 begins to engage with the hole 101a of the article 100, when a force in the direction opposite to the conveying direction of the conveying device 2 is detected by the force sensor 32, the working robot 10 follows and moves the part 110 slightly in the direction opposite to the conveying direction to avoid the detected force.

[0112] Next, the working robot control unit 21 performs a first abnormal response operation (step S1-11) when the position of the detection object O relative to the sensor 50 changes beyond a predetermined reference (step S1-10). Changes exceeding the predetermined reference include a large movement of the detection object O in the image data, a movement faster than the predetermined speed of the detection object O in the image data, and the disappearance of the detection object O at an unexpected time. In the case of unstable power supply, there is a case where the rotation speed of the motor 2a drops sharply, and there is also a case where the rotation speed of the motor 2a changes significantly. In these cases, the position of the detection object O relative to the sensor 50 changes beyond the predetermined reference.

[0113] In addition, steps S1 - 10 and S1 - 11 may be performed before the start of the fitting operation (step S1 - 8 ).

[0114] As the first abnormality response operation, the working robot control unit 21 performs an operation to shorten the control cycle of the force sense control or to increase the sensitivity, an operation to stop the movement of the fitting, an operation to terminate the fitting operation, etc. If the control cycle of the force sense control is shortened or the sensitivity is increased, the working robot 10 can be moved more sensitively to the force applied to the part 110. In this embodiment, the working robot control unit 21 performs an operation to terminate or retreat the fitting operation, stops the transport device, or performs a combination of these operations, etc.

[0115] In addition, when the detection value of the force sensor 32 exceeds a predetermined reference value (step S1-12), the working robot control unit 21 performs a second abnormality corresponding operation (step S1-13). When the detection value of the force sensor 32 exceeds a predetermined reference value, there is a high possibility that an abnormal force is applied to the part 110, the article 100, etc. Therefore, the working robot control unit 21, as a second abnormality corresponding operation, performs an operation of making the working robot 10 retreat or stop, an operation of making the working robot 10 move at a low speed in a direction away from the direction of the force detected by the force sensor 32, an operation of stopping the conveying device 2, an operation of separating the hand 30 from the part 110, or a combination of these operations. In the present embodiment, the working robot control unit 21 performs an operation of stopping the working robot 10 and the conveying device 2.

[0116] On the other hand, the working robot control unit 21 determines whether the fitting operation has been completed (step S1-14), and if the fitting operation has been completed, sends a control command to the working robot 10 and the hand 30 (step S1-15). As a result, the hand 30 is separated from the part 110, and the hand 30 moves to the standby position or the place where the next part 110 is stored by the working robot 10.

[0117] The moving speed of the detection object O obtained in step S1-6 can also be used when the two sensors 50 cannot detect the position of the detection object O. For example, the working robot control unit 21 can change the setting position of the reference coordinate system 201 by using the positions of the two detection objects O detected at the previous moment and the moving speed calculated before the detection object O cannot be observed.

[0118] In addition, the processing tool is supported at the front end of the working robot 10, and as a predetermined operation, the working robot 10 can also process the article 100 transported by the transport device 2. In this case, the processing tool is a drill, a milling cutter, a drilling and tapping compound tool, a deburring tool, and other tools. Even in this case, in step S1-2, the processing tool approaches the object part 101, and in step S1-9, force control is performed according to the contact between the processing tool and the object part 101, thereby achieving the same effect as above.

[0119] In addition, another control device may also appropriately perform detection of the characteristic shape and / or the position of the characteristic points of the article 100 in step S1 - 5 and step S1 - 6 .

[0120] In addition, when the position of the detection object O is sequentially detected in the second process, the correction data of the first process can also be obtained. In this case, it is not necessary to perform the first process (step S1-4).

[0121] Thus, in the present embodiment, the sensor 50 is arranged at a predetermined position, and the position of the object part 101 in the article 100 is sequentially detected using the detection data of the sensor 50. And, the working robot 10 is controlled using the position of the object part 101 detected sequentially in this way. Therefore, even in a state without force control, the working robot control unit 20 can identify the positional relationship between the part 110 or tool supported by the working robot 10 and the article 100, and can also identify whether the two are in contact. For example, the working robot control unit 21 can also identify an abnormality of the conveying device 2 in which the movement amount of the article 100 conveyed by the conveying device 2 changes significantly in a state without force control. Therefore, it is possible to prevent the working robot 10, the conveying device 2, and the article 100 from being damaged, and to suppress the occurrence of oscillation of the working robot 10 without excessively shortening the control cycle of the force control.

[0122] Here, there is also the following idea: the sensor 50 is supported by the front end of the working robot 10, or the front end of a robot different from the working robot 10, and when the robot changes the position and posture of the sensor 50 according to the handling of the handling device 2, the accuracy of detecting the position of the object part 101 using the detection data of the sensor 50 is improved. However, if the sensor 50 is supported by the front end of the robot, the position and posture of the sensor 50 are often not completely accurate due to the accuracy of the robot calibration, the influence of the robot's deflection, the absolute accuracy of the robot, etc. In contrast, in the present embodiment, the sensor 50 is configured at a predetermined position using a support member such as a bracket 51 and a frame 52. Therefore, compared with the case where the sensor 50 is supported by the front end of the robot, the accuracy of detecting the position of the object part 101 using the detection data of the sensor 50 is improved.

[0123] In addition, it is also possible to use a sensor 50 supported at the front end of the robot and a sensor 50 arranged at a predetermined position by a support member such as a bracket 51 or a frame 52. For example, in the present embodiment, a robot different from the working robot 10 can be used to support the sensor 50 supported by the frame 52. In this case, the robot can be used to change the position and posture of the sensor 50 according to the conveyance of the conveying device 2. When there is a possibility that the article 10 conveyed by the conveying device 2 may have a change in the moving speed in the X-axis direction, a vibration in the Z-axis direction, etc., the sensor 50 supported by the bracket 51 can be used to accurately detect the change in the moving speed, vibration, etc. occurring in the object part 101. That is, by having the sensor 50 supported by the bracket 51, the matter of detecting the position of the object part 101 by the sensor 50 supported by the robot is strengthened.

[0124] In addition, when the sensor 50 is supported on the front end of the working robot 10 together with the part 110 or the tool, there is a case where the field of view (detection range) of the sensor 50 is blocked by the part 110 or the tool. When the part 110 or the tool is in contact with the article 100, there is also a case where the sensor 50 cannot detect the target part 101 or its vicinity. In this embodiment, the sensor 50 is not supported on the working robot 10. Therefore, the possibility of the detection range of the sensor 50 being blocked by the part 110 or the tool is reduced, and the detection state of the sensor detecting the target part 101 or its vicinity when the part 110 or the tool is in contact with the article 100 can also be improved.

[0125] In addition, when the sensor 50 is supported on the front end of the working robot 10 together with the part 110 or the tool, it is necessary to remove the sensor 50 from the working robot 10 when cleaning or repairing the tool or the working robot 10. In this case, when the sensor 50 is mounted on the working robot 10 again, it is necessary to calibrate the sensor 50. In this embodiment, since the sensor 50 is not supported on the working robot 10, the time and labor for calibrating the sensor 50 can be reduced or eliminated.

[0126] In addition, in the present embodiment, the working robot control unit 21 makes the part 110 or tool of the working robot 10 track the target part 101 by using the detection result of the sensor 50. Therefore, the working robot control unit 21 can accurately control the position and posture of the part 110 or tool supported by the working robot 10 with respect to the target part 101 of the article 100 transported by the transport device 2 when the working robot 10 performs a predetermined operation. This is advantageous in preventing damage to the working robot 10, the transport device 2, the article 100, etc. without shortening the control cycle of the force sense control or increasing the sensitivity, and is also advantageous in suppressing the occurrence of oscillation of the working robot 10.

[0127] In addition, in the present embodiment, the sensor 50 is used to detect the detection object O whose position relative to the object part 101 does not change, thereby sequentially detecting the position of the object part 101. Therefore, even if the object part 101 is covered by the part 110 or the tool, the position of the object part 101 can be sequentially detected, which is extremely helpful in improving the accuracy of the work performed by the working robot 10.

[0128] In addition, in the present embodiment, there is a detection device 40 for detecting at least the position of the article 100 on the transport device 2, and the working robot control unit 21 makes the part 110 or the tool of the working robot 10 approach the object part 101 based on the detection result of the detection device 40. In addition, when approaching, the working robot can also change the posture of the part 110 or the tool according to the posture of the object part.

[0129] If the working robot 10 works in this way based on the detection result of the detection device 40, the working efficiency is improved. At this time, the working robot control unit 21 also uses the detection result of the working position detection device 2b to make the part 110 supported by the working robot 10 close to the target part 101, so that the above control becomes more accurate.

[0130] Furthermore, in the present embodiment, when the position of the target portion 101 or the detection target O observed from the sensor 50 changes beyond a predetermined reference, the working robot control unit 21 performs an abnormality handling operation.

[0131] In this structure, in a state where the positional relationship between the parts 110, the tool and the article 100 supported by the working robot 10 is recognized, the working robot control unit 2021 also performs abnormal response operations based on the detection results of the sensor 50. This structure is conducive to accurately preventing the working robot 10, the transport device 2, and the article 100 from being damaged, and is also conducive to suppressing the occurrence of vibration of the working robot 10.

[0132] In the present embodiment, the detection device 40 is a photoelectric sensor, but the detection device 40 may also be a two-dimensional camera, a three-dimensional camera, a three-dimensional distance sensor, or a sensor that irradiates a line light to an object and measures the shape, etc., which are arranged above, to the side, or below the conveying device 2. When the detection device 40 is a two-dimensional camera, there is also the following situation: the working robot control unit 21 is capable of recognizing the position and posture of the object part 101 of the article 100 conveyed by the conveying device 2 based on the image data as the detection result of the detection device 40. Therefore, in step S1-2, the working robot control unit 21 can make the axis 111a of the part 110 approach the hole 101a of the object part 101 more accurately.

[0133] In addition, as the transport device 2, it is possible to use a transport device that transports the article 100 along a curved track, and it is also possible to use a transport device that transports the article 100 along a winding track. Even in these cases, the working robot control unit 21 can use the detection result of the sensor 50 to make the part 110 supported by the working robot 10 follow the object part 101. In addition, when the position of the detection object O relative to the sensor 50 exceeds the predetermined reference and changes in step S1-10, the working robot control unit 21 can perform the first abnormal response action in step S1-11. That is, even when using the above-mentioned transport device, the same effect as above is achieved.

[0134] In addition, steps S1 - 10 and S1 - 11 may be performed before starting the fitting operation (step S1 - 8 ).

[0135] In addition, the acquisition of the position in step S1-6 is calculated based on the image data captured by the sensor 50. Therefore, the acquisition period of the position depends on the capturing period of the sensor 50. In contrast, it is also possible to interpolate the positions acquired sequentially based on the capturing data of the sensor 50. For example, the working robot control unit 21 uses the detection results of a plurality of consecutive positions and the tendency of the change of the specific position and the movement amount. Moreover, the working robot control unit 21 can set the interpolation position between the detection position and the detection position along a specific tendency.

[0136] In step S1 - 11 , the working robot control unit 21 may further stop the motor 2 a of the transport device 2 , decelerate the motor 2 a of the transport device 2 , and the like as the first abnormality handling operation.

[0137] In the present embodiment, a force sensor 32 is installed at the front end of the working robot 10. On the other hand, the force sensor 32 can also be arranged inside the hand 30, inside the robot 10, between the transport device 2 and the object 100, inside the object 100, etc. Even in this case, force sense control can be performed based on the detection value of the force sensor 32, and the same effect as above can be achieved.

[0138] In addition, instead of the frame 52, a moving device 61 for moving the sensor 50 may be used. Figure 8 As shown, the moving device 61 includes: a rail 63 extending in the X-axis direction; a slider 64 supported by the rail 63; and a servo motor 65 and a ball screw 65a, which move the slider 64 along the rail 63. In this case, when the control based on the position method is performed, the moving device 61 can fix the position and posture of the sensor 50.

[0139] In this embodiment, two sensors 50 detect the detection target O provided on the upper surface and the side surface of the object 100. On the other hand, a sensor 50 may be provided to detect the detection target O on the back surface of the object 100. In this case, the three-dimensional position and posture of the target part 101 can be detected.

[0140] Furthermore, in this embodiment, when detection by one sensor 50 cannot be performed for some reason, the above-mentioned position-based control method can be performed using only the detection data of another sensor 50. In addition, the sensors 50 can be arranged in the conveying direction of the conveying device 2, and the sensors 50 suitable for the position-based control method are switched in sequence.

[0141] In addition, instead of using two sensors 50 to detect the detection object O respectively, when using two or any one of the sensors 50 to detect the object part 101, the working robot control unit 21 applies well-known image processing, thereby being able to use, for example, Figure 3 The image data of the working robot 21 can identify the position of at least one of the two object parts 101. Figure 3 The posture of the object part 101 is specified by using the characteristic shape or a plurality of characteristic points of the object part 101 in the image data.

[0142] In addition, in step S1-7 as a part of the second process, the action program 23b may be corrected instead of moving the reference coordinate system 201. In this case, the working robot control unit 21 sequentially corrects the teaching points of the action program 23b that have been taught in advance with respect to the reference coordinate system 201 based on the difference between the reference position on the reference coordinate system 201 and the actual position (detected position). Even in this case, the same effects as above are achieved.

Claims

1. A working robot system, characterized in that: have: a handling device, which carries items; a working robot that performs a predetermined operation on a target portion of the article transported by the transport device; a working robot control unit that controls the working robot; a first sensor disposed at a first predetermined position and configured to detect a position of a first detection object, which is different from the target portion and has a position that does not change relative to the target portion, in a first surface of the article transported by the transport device; a second sensor disposed at a second predetermined position and configured to detect a position of a second detection object on a second surface of the article transported by the transport device that is different from the target portion and whose position does not change relative to the target portion; as well as a force detection unit that detects a force generated by contact between a part or a tool supported by the working robot and the object, The first sensor and the second sensor are not supported by the front end of the working robot, and the first sensor and the second sensor have mutually non-overlapping field angles. When the working robot is used to perform the predetermined work, the working robot control unit controls the working robot as follows: based on the detected positions of the first detection object and the second detection object, the part or the tool supported by the working robot follows the object part, and force control is performed based on the detection value of the force detection unit.

2. The working robot system according to claim 1, characterized in that: The working robot system includes a detection unit for detecting at least the position of the article on the transport device. The working robot control unit causes the part or the tool of the working robot to approach the target portion based on the detection result of the detection unit.

3. The working robot system according to claim 1 or 2, characterized in that: When the detection position of the target portion or the first and second detection objects changes beyond a predetermined reference, at least one of the working robot control unit and the transport device performs an abnormality response operation.

4. A working robot, characterized in that: have: an arm that performs a predetermined operation on a target portion of an article transported by the transport device; a working robot control unit that controls the arm; and a force detection portion that detects a force generated by contact between a part or a tool supported by the arm and the object, The working robot control unit receives data on the positions of a first detection object and a second detection object from a measuring device having a first sensor and a second sensor, wherein the first sensor is used to detect the position of the first detection object whose position in a first surface of the article moved by the conveying device does not change relative to the object portion, and the second sensor is used to detect the position of the second detection object whose position in a second surface of the article moved by the conveying device does not change relative to the object portion. The first sensor and the second sensor are not supported by the front end of the arm, and the first sensor and the second sensor have non-overlapping field angles. When the arm is used to perform the predetermined work, the working robot control unit controls the arm as follows: using data about the positions of the first detection object and the second detection object, the part or the tool supported by the arm follows the object part, and at the same time, force control is performed based on the detection value of the force detection unit.

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