Burr removal device and control system

Abstract

The present application provides a burr removing device and a control system, which are easy to correct detection errors of a vision sensor and errors of a robot mechanism. The burr removing device has a robot program generating unit that generates a program according to data of an object; a burr removing site detecting unit that detects a position of a burr removing site of one workpiece as the object by a vision sensor; a robot program updating unit that updates the program according to the detected position of the burr removing site; a force control unit that is controlled in a manner to become a predetermined pressing force; an actual trajectory obtaining unit that obtains an actual trajectory of the robot when the updated program is controlled in the predetermined pressing force; a trajectory correction parameter calculating unit that calculates a correction parameter of the position of the burr removing site of the one workpiece according to a trajectory of the robot in the vision sensor and the actual trajectory; the robot program updating unit updates the program according to a position that is corrected by the correction parameter for the detected position of the burr removing site of another workpiece; and the force control unit is controlled in the manner to become the predetermined pressing force based on the updated program.

Description

TECHNICAL FIELD

[0001] The present application relates to a burr removing device and a control system. BACKGROUND

[0002] In a burr removing process by a robot, there is known a technique in which (1) a shape of a burr removing portion and a posture of a tool of the robot are obtained from three-dimensional data of a workpiece offline, a robot program is generated, (2) a shape of the workpiece is detected in an actual machine using a camera (hereinafter, also referred to as a "vision sensor"), the robot program is updated based on a detection result, and (3) the robot program is executed in the actual machine, a force acting on the workpiece is detected using a force sensor mounted to a wrist of the robot, and burr removing is performed while force control is performed in such a manner that a detection value becomes a target value. For example, refer to Patent Literature 1.

[0003] PRIOR ART DOCUMENTS

[0004] PATENT LITERATURE

[0005] Patent Literature 1: Japanese Patent No. 5845212 SUMMARY

[0006] PROBLEMS TO BE SOLVED BY THE INVENTION

[0007] As described above, the conventional burr removing device performs burr removing processing as shown in FIG. 1. Figure 7

[0008] That is, in step S1, the burr removing device generates a program in advance based on three-dimensional data of a workpiece offline as described above. Further, one program is prepared for one workpiece.

[0009] In step S2, the burr removing device performs detection of the workpiece using the vision sensor each time, and based on a detection result, a teaching position of the program generated in step S1 is corrected.

[0010] In step S3, the burr removing device performs burr removing while force control is performed using the force sensor in such a manner that a pressing force becomes constant.

[0011] In step S4, the burr removing device determines whether or not there is a next workpiece, and in the case where there is a next workpiece, the processing returns to step S1, and in the case where there is no next workpiece, the processing ends.

[0012] As shown in FIG. 1, even if a set position of the workpiece and a burr shape are different, since correction is performed each time by the camera and the force sensor, it is possible to stabilize burr removing quality. Figure 7

[0013] However, in the conventional burr removing device, since the force sensor is mounted to the wrist of the robot, the robot is large in size, and the robot is expensive. Figure 7 ​​In the burr removal processing shown, there are cases where the burr removal quality is unstable. For example, depending on the size of the detection error of the vision sensor, the speed of the burr removal operation, it can not be possible to completely compensate for the error using the force sensor, and the workpiece can be pressed with too much force, or conversely, moved away from the workpiece, thereby deteriorating the burr removal quality.

[0014] In addition, in general, the parameters of the robot mechanism (hereinafter, also referred to as "mechanism parameters") are set to values in which the position error is made small on average in the entire operation region of the robot, but sometimes the precision for performing burr removal is insufficient. The precision of the robot mechanism not only affects the machining operation, but also the calibration (setting of the relative position) precision between the robot mechanism and the vision sensor.

[0015] By detecting multiple sites by narrowing the range detected by the vision sensor, or performing calibration in multiple regions, it is possible to reduce the error, but the cycle time at the time of production will be lengthened, and in addition, the workload of the user at the time of startup will be increased.

[0016] Therefore, it is desirable to easily correct the detection error of the vision sensor, the error of the robot mechanism.

[0017] Means for solving the problem

[0018] (1) One embodiment of the burr removing apparatus of the present disclosure is a burr removing apparatus provided with a burr removing robot manipulator that removes a burr from an object, in which the burr removing apparatus is provided with: a robot program generation section that generates in advance a robot program for performing burr removal; a burr removal site detection section that detects a position of a burr removal site of one workpiece that is the object, using a vision sensor; a robot program update section that updates the robot program according to the position of the burr removal site of one workpiece that is the object obtained by the burr removal site detection section; a force control section that detects a force acting on the robot manipulator and one workpiece that is the object, and controls the force to be a predetermined pressing force; an actual trajectory acquisition section that acquires an actual trajectory of the robot manipulator based on the robot program updated by the robot program update section, when the robot manipulator is controlled by the force control section to be the predetermined pressing force; and a trajectory correction parameter calculation section that calculates a correction parameter related to the position of the burr removal site of one workpiece that is the object detected by the burr removal site detection section, according to a difference between a movement trajectory of the robot manipulator detected by the vision sensor when the robot manipulator is controlled by the force control section to be the predetermined pressing force, and the actual trajectory, the robot program update section further updates the robot program based on a position of a corrected burr removal site obtained by correcting the position of the burr removal site of another workpiece that is the object detected by the burr removal site detection section, using the correction parameter calculated by the trajectory correction parameter calculation section, and the force control section further detects a force acting on the robot manipulator and another workpiece that is the object, and controls the force to be the predetermined pressing force, based on the robot program updated by the robot program update section.

[0019] (2) One embodiment of the control system of the present disclosure is a control system of a robot that processes an object, and includes: a generation unit that generates, in advance, a motion program for causing the robot to perform a motion; a detection unit that detects, by a vision sensor, a workpiece that is one of the objects; an update unit that updates the motion program based on a detection result of the workpiece that is one of the objects obtained by the detection unit; a control unit that controls a processing motion of the robot with respect to the workpiece that is one of the objects based on the motion program updated by the update unit; an acquisition unit that acquires an actual trajectory of the processing motion of the robot when the robot is controlled by the control unit based on the motion program updated by the update unit; and a calculation unit that calculates a correction parameter related to the detection result of the workpiece that is one of the objects detected by the detection unit based on a trajectory of the processing motion of the robot detected by the detection unit when the robot is controlled by the control unit and the actual trajectory. The update unit updates the motion program based on a corrected detection result of another workpiece that is one of the objects detected by the detection unit, which is corrected by the correction parameter calculated by the calculation unit. The control unit controls a processing motion of the robot with respect to another workpiece that is one of the objects based on the motion program updated by the update unit.

[0020] Effects of Invention

[0021] According to one embodiment, it is possible to easily correct a detection error of a vision sensor and an error of a robot mechanism unit. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 is a functional block diagram showing an example of a functional configuration of a burr removing device according to an embodiment.

[0023] Figure 2 is a diagram showing an example of a robot.

[0024] Figure 3 is a diagram for explaining a coordinate system of a robot. Figure 2

[0025] Figure 4 is a diagram showing an example of a detection trajectory detected by a vision sensor and a low-speed contouring trajectory using a force sensor.

[0026] Figure 5 is a flowchart for explaining a burr removing process of a burr removing device.

[0027] Figure 6 is a diagram showing an example of a detection trajectory detected by a vision sensor and a low-speed contouring trajectory using a force sensor.

[0028] ​Figure 7 is a flowchart for explaining a burr removal process of a conventional burr removal device. DETAILED DESCRIPTION

[0029] Hereinafter, one embodiment will be explained using the drawings.

[0030] <Embodiment>

[0031] Figure 1 is a functional block diagram showing an example of a functional configuration of a burr removal device according to an embodiment. As shown in Figure 1 , the burr removal device 1 has a mechanical device 10 and a control device 20. Hereinafter, the mechanical device 10 as a robot and the control device 20 as a robot control device will be explained, but are not limited thereto.

[0032] The mechanical device 10 and the control device 20 can also be directly connected to each other via a connection interface not shown. In addition, the mechanical device 10 and the control device 20 can also be connected to each other via a network such as a LAN (Local Area Network). In this case, the mechanical device 10 and the control device 20 can also be provided with a communication section not shown for communicating with each other through the connection.

[0033] The mechanical device 10 is, for example, a machine tool, an industrial robot, or the like. Hereinafter, the mechanical device 10 will be explained as an industrial robot (hereinafter, also referred to as "robot 10").

[0034] Figure 2 is a diagram showing an example of the robot 10.

[0035] As shown in Figure 2 , the robot 10 is, for example, a 6-axis vertical multi-joint robot having six joint axes 11(1) to 11(6) and arm portions 12 connected to the joint axes 11(1) to 11(6), respectively. The robot 10 drives movable members (hereinafter, also referred to as "manipulators") such as the arm portions 12 based on a drive instruction from the control device 20, by driving servo motors not shown provided to the joint axes 11(1) to 11(6), respectively. In addition, a vision sensor 13, a force sensor 14, and a burr removal tool (hereinafter, also referred to as "tool") 15 are attached to, for example, the front end portion of the joint axis 11(6) of the manipulator of the robot 10.

[0036] In addition, the robot 10 is a 6-axis vertical multi-joint robot, but can also be a vertical multi-joint robot other than 6-axis, and can also be a horizontal multi-joint robot, a parallel link robot, or the like.

[0037] In addition, hereinafter, the joint axes 11(1) to 11(6) will be collectively referred to as "joint axes 11" without separately distinguishing them.

[0038] Figure 3 is a diagram for explaining Figure 2 coordinate systems in the robot 10.

[0039] As shown in Figure 3 , the robot 10 has a world coordinate system Σw of a 3-dimensional orthogonal coordinate system fixed to space and a mechanical interface coordinate system Σm of a 3-dimensional orthogonal coordinate set to a flange of a front end of the joint axis 11(6) of the robot 10. In the present embodiment, the correlation of the positions of the world coordinate system Σw and the mechanical interface coordinate system Σm is obtained in advance by a known calibration. Thereby, the control device 20 described later can control the position of the front end portion of the robot 10 on which the tool 15 described later is mounted using the position defined by the world coordinate system Σw.

[0040] The vision sensor 13 is, for example, a camera, as shown in Figure 2 , provided to a front end portion of a manipulator of the robot 10. The vision sensor 13 functions as a burr removal site detection portion by having an image processing portion not shown.

[0041] Specifically, the vision sensor 13 processes an image obtained by photographing the workpiece 30 on which burr removal is to be performed, which is arranged on the workbench 40, and detects the position of a site (hereinafter, also referred to as "burr removal site") in the workpiece 30 where a burr should be removed. The vision sensor 13 outputs data indicating the position of the detected burr removal site to the control device 20 via a connection interface not shown.

[0042] Further, the vision sensor 13 can also obtain data (hereinafter, referred to as "burr removal site shape data") related to the shape and position of the burr removal site in the workpiece 30 in advance from an offline programming device or the like not shown when detecting the position of the burr removal site. In addition, the vision sensor 13 can also detect an edge feature line represented by a boundary of brightness from an image obtained by photographing the workpiece 30 using a known method of Patent Literature 1 or the like, and regard the above feature line as the burr removal site. In addition, the vision sensor 13 can also be further formed to detect the position of the actual workpiece 30.

[0043] In addition, the vision sensor 13 can also further have a search area limiting portion (not shown) that limits a search area in a photographed image of the workpiece 30 based on the burr removal site shape data. Thereby, the vision sensor 13 can detect the position of the actual burr removal site from the limited search area, can shorten the time required to detect the position of the actual burr removal site, and can perform stable detection without detecting an erroneous site.

[0044] Here, the off-line programming device (not shown) described above is a computer device, and can also store the three-dimensional data of the workpiece 30 in advance, and extract the burr removal site shape data related to the shape and position of the burr removal site of the workpiece 30 from the three-dimensional data of the workpiece 30. In addition, the off-line programming device (not shown) can also set the posture of the tool 15 described later corresponding to the burr removal site at the time of performing burr removal, based on the burr removal site shape data. The posture of the tool 15 can be set to a certain angle with respect to the surface of the workpiece 30 throughout the entire burr removal site, or can be set locally taking into account external factors such as obstacles existing around the robot 10.

[0045] The force sensor 14 is, for example, a 6-axis force sensor, and is provided at the front end portion of the manipulator of the robot 10. The force sensor 14 periodically detects the pressing force of the tool 15 against the workpiece 30 at a predetermined sampling time. The force sensor 14 outputs force data indicating the detected pressing force to the control device 20 via a connection interface not shown.

[0046] In addition, the servomotors (not shown) of the joint axes 11 are, for example, provided with position sensors (not shown) such as rotary encoders, and measure the position and posture of the front end portion of the manipulator. The position sensors (not shown) can also output position data indicating the measured position and posture to the control device 20 via a connection interface not shown.

[0047] In addition, the predetermined sampling time can also be appropriately set in accordance with the contents of the action of the robot 10, the environment of the factory in which the robot 10 is installed, and the like.

[0048] The tool 15 is a grinder or the like, and is provided at the front end portion of the manipulator of the robot 10, and removes the burrs generated on the workpiece 30.

[0049] <Control device 20>

[0050] As shown in Figure 1 and Figure 2 , the control device 20 is a robot control device (also referred to as a "robot controller") that outputs drive instructions to the robot 10 based on a program, and controls the action of the robot 10. In addition, in Figure 2 , the teach pendant 25 that teaches the action of the robot 10 is connected to the control device 20.

[0051] As shown in Figure 1 , the control device 20 of the present embodiment has a control section 200. In addition, the control section 200 has a robot program generation section 210, a robot program update section 220, a force control section 230, an actual trajectory acquisition section 240, and a trajectory correction parameter calculation section 250.

[0052] The control section 200 has a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM, a CMOS (Complementary Metal-Oxide-Semiconductor) memory, and the like, which are configured to be able to communicate with each other via a bus, and are well known to those skilled in the art.

[0053] The CPU is a processor that controls the entire control device 20. The CPU reads out a system program and an application program saved in the ROM via the bus, and controls the entire control device 20 in accordance with the system program and the application program. Thus, as shown in FIG. 2, the control section 200 is configured to realize the functions of a robot program generation section 210, a robot program update section 220, a force control section 230, an actual trajectory acquisition section 240, and a trajectory correction parameter calculation section 250. Various data such as temporary calculation data and display data are stored in the RAM. In addition, the CMOS memory is backed up by a battery that is not shown, and is configured as a nonvolatile memory that maintains a storage state even when the power supply of the control device 20 is turned off. Figure 1

[0054] The robot program generation section 210 generates a robot program for performing burr removal based on three-dimensional data that represents the shape of the workpiece 30.

[0055] Specifically, the robot program generation section 210 generates a robot program of the robot 10, for example, from three-dimensional data of the workpiece 30 that includes burr removal site shape data and a posture of the tool 15, which is acquired from an off-line programming device (not shown). In addition, one robot program can be prepared for one kind of workpiece.

[0056] With this robot program, the tool 15, that is, the movement path and the movement speed and the like of the robot 10 for appropriately performing burr removal can also be specified. In addition, in the robot program, in addition to a control signal for the robot 10, a predetermined pressing force (hereinafter, also referred to as a "target value") that is predetermined and is set in advance for the purpose of force control of the robot 10, which acts on the tool 15, can also be included. In addition, the target value of the pressing force can include information of a pressing direction in addition to the magnitude of the pressing force.

[0057] The robot program update section 220 updates the robot program generated by the robot program generation section 210. For example, when the position of the actual burr removal site is detected by the vision sensor 13, the robot program update section 220 updates the robot program based on the detection result to change the movement path of the robot 10.

[0058] ​In addition, the robot program updating section 220 can also update the robot program based on a correction parameter that corrects the detection result of the vision sensor 13, which is calculated by the trajectory correction parameter calculating section 250 described later, correct the position of the burr removal site of the workpiece 30 detected by the vision sensor 13 using the correction parameter, and update the robot program based on the corrected position of the burr removal site.

[0059] The force control section 230 causes the robot 10 to move by executing the robot program updated by the robot program updating section 220, for example, by the control device 20, and thereby detects the pressing force of the tool 15 acting on the workpiece 30 using the force sensor 14 mounted to the front end of the robot 10. The force control section 230 performs force control in such a manner that the detected pressing force of the tool 15 becomes a target value.

[0060] The actual trajectory obtaining section 240 obtains the actual trajectory of the motion of the manipulator of the robot 10, i.e., the tool 15, when the force control section 230 controls in such a manner that the pressing force of the force sensor 14 becomes a target value, based on the robot program updated by the robot program updating section 220.

[0061] Specifically, the actual trajectory obtaining section 240 causes the robot 10 to actuate the updated robot program to perform profiling of the workpiece 30 at a speed (e.g., a speed slower than the speed at the time of burr removal (hereinafter, also referred to as "low speed")) at which the pressing force detected by the force sensor 14 becomes a target value, before burr removal is performed using the tool 15 mounted to the robot 10 after the workpiece 30 is detected using the vision sensor 13. In this case, the robot 10 can not perform burr removal processing.

[0062] The actual trajectory obtaining section 240 obtains the trajectory of the tool 15 as an actual trajectory (hereinafter, also referred to as "low-speed profiling trajectory") based on the data output from the position sensor of the non-illustrated servo motor of the joint axis 11 at the time of profiling of the workpiece 30 at a low speed using the force sensor 14.

[0063] The trajectory correction parameter calculating section 250 calculates a correction parameter related to the position of the burr removal site of the workpiece 30 detected by the vision sensor 13, from the difference between the trajectory of the motion of the tool 15 detected by the vision sensor 13 at the time when the pressing force is controlled to a target value by the force control section 230 (hereinafter, also referred to as "detected trajectory") and the low-speed profiling trajectory using the force sensor 14.

[0064] Figure 4 is a diagram showing an example of the detected trajectory detected by the vision sensor 13 and the low-speed profiling trajectory using the force sensor 14. In addition, in Figure 4 , the detected trajectory is shown by a solid line and the low-speed profiling trajectory is shown by a dashed line. In addition, inFigure 4 In this context, the detection trajectory and low-speed contouring trajectory represent circular trajectories, but they can also be trajectories of any shape. The processing operation of the trajectory correction parameter calculation unit 250 is the same. Furthermore, the following explanation covers corrections for parallel movement and zoom-in / zoom-out, but corrections for rotation direction can also be handled in the same way.

[0065] like Figure 4 As shown, the detection trajectory detected by the vision sensor 13 is offset from the low-speed contouring trajectory using the force sensor 14. Therefore, the trajectory correction parameter calculation unit 250 calculates the correction parameters that minimize the difference between the two trajectories.

[0066] Therefore, the point sequence of the detection trajectory detected by the vision sensor 13 is defined as (x 1i y 1i The point sequence of the low-speed contour trajectory using force sensor 14 is defined as (x 2i y 2i (i is an integer from 1 to n, and n is an integer greater than 2).

[0067] The trajectory correction parameter calculation unit 250 corrects the point array (x) of the detection trajectory detected by the vision sensor 13. 1i y 1i And when it is made consistent with the low-speed contour trajectory using force sensor 14, the corrected point sequence (x') 1i y' 1i The correction parameter AD is expressed as in mathematical formula 1.

[0068] [Mathematical Expression 1]

[0069] x′ 1i =Ax 1i +B

[0070] y′ 1i =Cy 1i +D

[0071] The trajectory correction parameter calculation unit 250 calculates the point sequence (x) of the detection trajectory detected by the vision sensor 13 using the least squares method. 1i y 1i ) and the point array (x) using the low-speed contour trajectory of force sensor 14 2i y 2i The most recent correction parameter AD. Furthermore, the calculation of the X component will be explained below, but the Y component can also be calculated using the same method.

[0072] The trajectory correction parameter calculation unit 250 uses mathematical formula 2 to calculate the sum of squares of the trajectory error with respect to the X component.

[0073] [Mathematical Expression 2]

[0074]

[0075] The trajectory correction parameter calculation section 250 solves the simultaneous equations of mathematical expression 3 so as to make the formula obtained by partial differentiation using each correction parameter 0, in order to find the correction parameters A and B that make S the smallest.

[0076] [mathematical expression 3]

[0077]

[0078] Mathematical expression 3 can be transformed as mathematical expression 4.

[0079] [mathematical expression 4]

[0080]

[0081] Here, by defining the matrix X, the vector a, and the vector y respectively as shown in mathematical expression 5, mathematical expression 4 can be expressed as X-a = y.

[0082] [mathematical expression 5]

[0083]

[0084]

[0085]

[0086] Accordingly, the vector a of the correction parameters is expressed using the matrix X and the vector y as mathematical expression 6.

[0087] [mathematical expression 6]

[0088] a = (X T X) -1 X T y

[0089] And since the matrix X and the vector y are known quantities calculated from the data of each trajectory point column, the trajectory correction parameter calculation section 250 can calculate the correction parameters A and B according to mathematical expression 6. Similarly, the trajectory correction parameter calculation section 250 can calculate the correction parameters C and D of the Y component.

[0090] The trajectory correction parameter calculation section 250 stores the calculated correction parameters A to D in a storage section (not shown) such as an HDD included in the control device 20.

[0091] Thus, the burr removing device 1, in a case where burr removing of the workpiece 30 of the same shape is performed, corrects the position of the burr removing site of the workpiece 30 detected by the vision sensor 13 using the calculated correction parameters A to D, and updates the robot program at the corrected position of the burr removing site, whereby it is possible to easily correct the detection error of the vision sensor 13.

[0092] Further, the burr removing device 1 requires the use of the profiling action of the force sensor 14 once the start is made, but since this action and the calculation of the correction parameters can be performed automatically, the working hours of the user are not increased.

[0093] <Burr removing process of burr removing device 1>

[0094] Next, the action involved in the burr removing process of the burr removing device 1 of the present embodiment will be described.

[0095] Figure 5 is a flowchart for describing the burr removing process of the burr removing device 1. In the following description, the plurality of workpieces 30 as burr removing objects have the same shape as each other.

[0096] In step Sll, the robot program generating section 210 generates a robot program from three-dimensional data of the workpiece 30 including the burr removing site shape data acquired from an off-line programming device (not shown) and the posture of the tool 15.

[0097] In step S12, the robot program updating section 220 updates the robot program based on the position of the burr removing site of the workpiece 30 detected by the vision sensor 13.

[0098] In step S13, the actual trajectory acquiring section 240 acquires the actual trajectory of the action of the tool 15 when the profiling at low speed is performed on the workpiece 30, i.e., the low-speed profiling trajectory, based on the robot program updated in step S12, by the force control section 230 controlling the pressing force of the force sensor 14 to be the target value.

[0099] In step S14, the trajectory correction parameter calculating section 250 calculates the correction parameters A to D based on the low-speed profiling trajectory acquired in step S13, the detection trajectory detected by the vision sensor 13 when the above low-speed profiling trajectory is acquired, and the mathematical formulae 5 and 6.

[0100] In step S15, the robot program updating section 220 corrects the position of the burr removing site of the workpiece 30 detected by the vision sensor 13 using the correction parameters A to D calculated in step S14, and updates the robot program based on the corrected position of the burr removing site.

[0101] In step S16, the control section 200 controls the pressing force of the tool 15 to be the target value using the force sensor 14 by the force control section 230 based on the robot program updated in step S15, and performs the burr removal of the workpiece 30.

[0102] In step S17, the control section 200 determines whether or not there is a next workpiece 30 as a burr removal object. In the case where there is the next workpiece 30, the process returns to step S15. On the other hand, in the case where there is no next workpiece 30, the burr removal processing of the burr removal device 1 ends.

[0103] By the above, the burr removal device 1 of one embodiment performs profiling of the workpiece 30 at a low speed using the tool 15 while controlling the pressing force detected by the force sensor 14 to be the target value before burr removal of the workpiece 30, thereby acquiring a low-speed profiling track. The burr removal device 1 calculates the correction parameters A to D based on the detected track detected by the vision sensor 13 when the low-speed profiling track is acquired and the low-speed profiling track. The burr removal device 1 corrects the position of the burr removal site of the workpiece 30 detected by the vision sensor 13 using the correction parameters A to D, and updates the robot program based on the position of the corrected burr removal site.

[0104] Thus, the burr removal device 1 can easily correct the detection error of the vision sensor 13. Also, the burr removal device 1 can maintain the burr removal quality constant even if there is a detection error of the vision sensor 13.

[0105] In other words, it is possible to correct the mechanism error of the robot 10, the calibration error between the vision sensor 13 and the robot 10, the detection error of the vision sensor 13, as shown in Figure 4 As shown, it is possible to make the detected track detected by the vision sensor 13 shown by the solid line close to the low-speed profiling track using the force sensor 14 shown by the broken line.

[0106] In addition, the burr removal device 1 needs to use the profiling action of the force sensor 14 once at the start, but since this action and the calculation of the correction parameters can be performed automatically, the working hours of the user do not increase.

[0107] The above describes one embodiment, but the burr removal device 1 is not limited to the above-described embodiment, and includes variations, modifications, and the like within a range capable of achieving the object.

[0108] <Modification Example 1>

[0109] In the embodiment described above, the trajectory correction parameter calculation section 250 calculates the correction parameters A to D so that the detected trajectory detected by the vision sensor 13 coincides with the low-speed profiling trajectory using the force sensor 14, but is not limited thereto. For example, the trajectory correction parameter calculation section 250 can also calculate correction parameters that correct the mechanism parameters of the robot 10 so that the low-speed profiling trajectory using the force sensor 14 coincides with the detected trajectory detected by the vision sensor 13. Further, as the mechanism parameters, there are the zero-degree angles, link lengths, and the like of the respective joint axes 11 of the robot 10.

[0110] Specifically, the trajectory correction parameter calculation section 250 calculates k mechanism parameters q1 to qk to be corrected among the mechanism parameters, the zero-degree angles, the link lengths, and the like, from the detected trajectory detected by the vision sensor 13 and the low-speed profiling trajectory using the force sensor 14. k Letting the error e of the mathematical expression 7 be an unknown, the error e is solved. j (k is an integer of 1 or more, and j is an integer of 2 or more).

[0111] [mathematical expression 7]

[0112] e j = P 1j - P 2j

[0113] Here, P 1j indicates the j-th position of the point series of the low-speed profiling trajectory when the low-speed profiling is performed under the condition in which the force control is effective using the force sensor 14. P 2j indicates the j-th position of the point series of the detected trajectory detected by the vision sensor 13. Further, P 1j indicates the position of each joint axis 11 of the robot 10 when the low-speed profiling is performed, and the mechanism parameters q1 to qk as unknowns. k are solved by forward kinematics calculation (forward transformation) of the robot. Further, the forward kinematics calculation (forward transformation) of the robot can use a publicly known method (for example, refer to J. J. Craig, "Robotics - Mechanisms, Kinematics, Control", "Chapter 3 Kinematics of Manipulators", Kyoritsu Shuppan, 1991, or R. P. Paul, "Robot Manipulators <Mathematical Foundations, Programming and Control>", "Chapter 1 Homogeneous Transformations", Corona Publishing Company, 1984), and detailed explanation is omitted.

[0114] The trajectory correction parameter calculation section 250 calculates the mechanism parameters q1 to qk that minimize the mathematical expression 8 that is the sum of squares of the errors e j of the mathematical expression 7. k as the correction parameters.

[0115] [mathematical expression 8]

[0116]

[0117] The trajectory correction parameter calculation section 250 calculates the mechanism parameters q1-q k As with the mathematical expression 4, the simultaneous equations of the mathematical expression 9 are solved by setting the partial differential with respect to each of the mechanism parameters to 0.

[0118] [mathematical expression 9]

[0119]

[0120] In the case where the simultaneous equations of the mathematical expression 9 are nonlinear, the trajectory correction parameter calculation section 250 can repeatedly calculate the mechanism parameters (correction parameters) q1-q k .

[0121] By the above-described method, it is possible to correct the mechanism error of the robot 10, the calibration error between the vision sensor 13 and the robot 10, and the detection error of the vision sensor 13, and as shown in FIG. 8, it is possible to make the solid line indicating the low-speed profiling trajectory using the force sensor 14 approach the detection trajectory detected by the vision sensor 13. Figure 6

[0122] Thus, the burr removing device 1 can easily correct the detection error of the vision sensor and the error of the robot mechanism, and can make the pressing force constant at the time of burr removal based on the force sensor 14, thereby improving the quality of burr removal.

[0123] <Modification example 2>

[0124] In addition, for example, in the above-described embodiment, the plurality of workpieces 30 are the same in shape, but are not limited thereto. For example, the plurality of workpieces 30 can be different in shape from each other. In this case, in the case where the shape of the workpiece 30 subjected to burr removal is changed, the burr removing device 1 needs to perform low-speed operation using the force sensor 14 for the above-described correction, but in the case where the change in trajectory from the existing workpiece is small, the existing correction parameters can be used. Alternatively, the burr removing device 1 can attempt to use the existing correction parameters for similar workpieces at one time, and determine whether the correction parameters need to be newly acquired based on the quality of burr removal at that time and the detection value of the force sensor 14 during burr removal.

[0125] <Modification example 3>

[0126] ​Further, in the above-described embodiment, the trajectory correction parameter calculation section 250 calculates the correction parameter using one detected trajectory detected by the vision sensor 13 and one low-speed tracing trajectory using the force sensor 14, but is not limited thereto. For example, in a case where the detected trajectory detected by the vision sensor 13 and the low-speed tracing trajectory using the force sensor 14 are large, the trajectory correction parameter calculation section 250 can also divide the detected trajectory using the vision sensor 13 and the low-speed tracing trajectory using the force sensor 14 into a plurality of sections, and perform correction for each of the divided trajectories.

[0127] That is, in a case where the detected trajectory detected by the vision sensor 13 and the low-speed tracing trajectory using the force sensor 14 are large, the value of the appropriate correction parameter in one trajectory is not constant. Therefore, the trajectory correction parameter calculation section 250 can also calculate the residual error S from the correction parameter determined using the least square method, and in a case where the calculated residual error S exceeds a predetermined value, for example, divide the circular trajectory into four equal parts, or divide the long straight line trajectory into a plurality of equal parts to divide the trajectory into a plurality of sections, and calculate the correction parameter for each section, and perform correction for each section.

[0128] <Modification Example 4>

[0129] Further, in the above-described embodiment, the control device 20 includes all of the robot program generation section 210, the robot program update section 220, the force control section 230, the actual trajectory acquisition section 240, and the trajectory correction parameter calculation section 250, and controls the robot 10, but is not limited thereto. For example, the control device 20 can include the robot program generation section 210, the robot program update section 220, and the trajectory correction parameter calculation section 250, and update only the robot program. In this case, a robot control device (not shown) that controls the outside of the robot 10 has the force control section 230 and the actual trajectory acquisition section 240, and the control device 20 can acquire the detected trajectory detected by the vision sensor 13 and the low-speed tracing trajectory using the force sensor 14 from the above-described robot control device (not shown).

[0130] <Modification Example 5>

[0131] Further, for example, in the above-described embodiment, the burr removing device 1 is provided with the robot 10 and the control device 20, but for example, as a control system having the robot 10 and the control device 20, the robot 10 can also be caused to perform sealing, laser processing, or the like. In this case, the visual sensor 13 (burr removal position detection section) of the burr removing device 1, the robot program generation section 210, the robot program update section 220, the force control section 230, the actual trajectory acquisition section 240, and the trajectory correction parameter calculation section 250 can also function as a detection section, a generation section, an update section, a control section, an acquisition section, and a calculation section of the control system.

[0132] For example, in the case of sealing, a nozzle that ejects a liquid such as paint is installed as the tool 15 at the front end of the robot 10, and the control system can correct the sealing operation of the robot 10, or correct the mechanism parameters of the robot 10, so that the trajectory error between the trajectory calculated from the position sensor (not shown) of the robot 10 and the detection trajectory obtained by detecting the actually sealed position by the visual sensor 13 becomes the minimum. Alternatively, the control system can install an acceleration sensor or a laser tracker, which are not shown, at the front end of the robot 10, and acquire the trajectory in sealing. The control system can correct the sealing operation of the robot 10, or correct the mechanism parameters of the robot 10, so that the error between the trajectory obtained and the trajectory calculated from the position sensor (not shown) of the robot 10 becomes the minimum.

[0133] Further, for example, in the case of laser processing, a laser cutter, a welding gun for laser welding, or the like can be installed as the tool 15 at the front end of the robot 10, and the control system corrects the processing operation of the robot 10, or corrects the mechanism parameters of the robot 10, so that the trajectory error between the trajectory calculated from the position sensor (not shown) of the robot 10 and the detection trajectory obtained by detecting the actually processed position by the visual sensor 13 becomes the minimum. Alternatively, the control system can install an acceleration sensor, a laser tracker, which are not shown, at the front end of the robot 10, and acquire the trajectory in processing. The control system can correct the processing operation of the robot 10, or correct the mechanism parameters of the robot 10, so that the error between the trajectory obtained and the trajectory calculated from the position sensor (not shown) of the robot 10 becomes the minimum.

[0134] Thus, the control system can easily correct the detection error of the visual sensor and the error of the robot mechanism section.

[0135] <Modification 6>

[0136] In addition, in the above-described embodiment, the visual sensor 13, the force sensor 14, and the tool 15 are attached to the front end portion of the robot 10, but are not limited thereto. For example, the visual sensor 13 can be fixedly provided at a position other than the front end portion of the robot 10 and can detect the positions of the workpiece 30 and the tool 15.

[0137] In addition, each function included in the burr removing device 1 of one embodiment can be realized by hardware, software, or a combination thereof. Here, realization by software means realization by a computer reading a program and executing the program.

[0138] In addition, each structural portion included in the burr removing device 1 can be realized by hardware including an electronic circuit and the like, software, or a combination thereof.

[0139] A program can be stored using various types of non-transitory computer readable media (Non-transitory computer readable medium) and provided to a computer. The non-transitory computer readable medium includes various types of tangible storage media (Tangible storage medium). Examples of the non-transitory computer readable medium include a magnetic recording medium (for example, a floppy disk, a magnetic tape, a hard disk drive), a magneto-optical recording medium (for example, a magneto-optical disk), a CD-ROM (Read Only Memory), a CD-R, a CD-R / W, and a semiconductor memory (for example, a mask ROM, a PROM (Programmable ROM), an EPROM (Erasable PROM), a flash ROM, and a RAM). In addition, a program can be provided to a computer through various types of transitory computer readable media (Transitory computer readable medium). Examples of the transitory computer readable medium include an electrical signal, an optical signal, and an electromagnetic wave. The transitory computer readable medium can provide a program to a computer via a wired communication path such as an electrical wire and an optical fiber or a wireless communication path.

[0140] Furthermore, the steps of describing a program recorded in a recording medium include not only processes performed in a time series in the order of the steps but also processes performed in parallel or individually without necessarily being performed in a time series.

[0141] In other words, the burr removing device and the control system of the present disclosure can take various embodiments having the following structures.

[0142] (1) The burr removing device 1 of the present disclosure is a burr removing device provided with a burr removing robot manipulator that removes burrs from an object, wherein the burr removing device is provided with: a robot program generation section 210 that generates in advance a robot program for performing burr removal; a burr removal site detection section (vision sensor 13) that detects the position of a burr removal site of one workpiece 30 that is an object by a vision sensor 13; a robot program update section 220 that updates the robot program in accordance with the position of the burr removal site of one workpiece that is an object obtained by the vision sensor 13; a force control section 230 that detects the force acting on the robot manipulator and one workpiece 30 that is an object, and controls it to be a predetermined pressing force; an actual trajectory acquisition section 240 that acquires the actual trajectory of the action of the robot manipulator when the force control section 230 controls it to be a predetermined pressing force, based on the robot program updated by the robot program update section 220; and a trajectory correction parameter calculation section 250 that calculates a correction parameter related to the position of the burr removal site of one workpiece that is an object detected by the burr removal site detection section (vision sensor 13) in accordance with the difference between the action trajectory of the robot manipulator detected by the vision sensor 13 when it is controlled to be a predetermined pressing force by the force control section 230 and the actual trajectory, the robot program update section 220 further updates the robot program based on the position of the corrected burr removal site obtained by correcting the position of the burr removal site of other workpieces 30 that are objects detected by the burr removal site detection section (vision sensor 13) by the correction parameter calculated by the trajectory correction parameter calculation section 250, and the force control section 230 further detects the force acting on the robot manipulator and other workpieces that are objects based on the robot program updated by the robot program update section 220, and controls it to be a predetermined pressing force.

[0143] According to the burr removing device 1, it is possible to easily correct the detection error of the vision sensor and the error of the robot mechanism section.

[0144] (2) In the burr removing device 1 described in technical solution (1), the correction parameter calculated by the trajectory correction parameter calculation section 250 can also be reflected in the detection result of the burr removal site detection section based on the vision sensor 13.

[0145] Thus, the burr removing device 1 can correct the detection error of the vision sensor with high precision.

[0146] (3) In the burr removing device 1 described in technical solution (1), the correction parameter calculated by the trajectory correction parameter calculation section 250 can also be reflected in the mechanism parameter of the robot manipulator.

[0147] Thus, the burr removing device 1 can correct the error of the robot mechanism portion with high precision.

[0148] (4) In the burr removing device 1 according to any one of (1) to (3), the trajectory correction parameter calculation portion 250 can further divide the trajectory of the action of the robot manipulator detected by the vision sensor 13 and the actual trajectory into a plurality of sections, and calculate the correction parameter for each of the plurality of sections, in a case where the residual S of the trajectory of the action of the robot manipulator detected by the vision sensor 13 and the actual trajectory calculated based on the calculated correction parameter exceeds a predetermined value set in advance.

[0149] Thus, the burr removing device 1 can calculate the correction parameter for each of the plurality of sections with high precision.

[0150] (5) A control system of the present disclosure is a control system of a robot 10 that processes an object, and includes: a generation portion (robot program generation portion 210) that generates in advance an action program that causes the robot 10 to act; a detection portion (vision sensor 13) that detects one workpiece that is the object by a vision sensor 13; an update portion (robot program update portion 220) that updates the action program based on a detection result of the one workpiece that is the object obtained by the detection portion; a control portion (force control portion 230) that controls the processing action of the one workpiece that is the object by the robot 10 based on the action program updated by the update portion; an acquisition portion (actual trajectory acquisition portion 240) that acquires an actual trajectory of the processing action of the robot 10 when controlled by the control portion based on the action program updated by the update portion; and a calculation portion (trajectory correction parameter calculation portion 250) that calculates a correction parameter related to the detection result of the one workpiece that is the object detected by the detection portion based on a trajectory of the processing action of the robot 10 detected by the detection portion and the actual trajectory when controlled by the control portion, and the update portion updates the action program based on a corrected detection result of another workpiece that is the object detected by the detection portion, which is corrected by the correction parameter calculated by the calculation portion. The control portion controls the processing action of the other workpiece that is the object by the robot 10 based on the action program updated by the update portion.

[0151] According to the control system, the same effects as (1) can be achieved.

[0152] Explanation of Reference Numerals

[0153] 1 burr removing device,

[0154] 10 robot,

[0155] 13 vision sensor,

[0156] 14 force sensor,

[0157] 15 tool,

[0158] 20 control device,

[0159] 200 control section,

[0160] 210 robot program generation section,

[0161] 220 robot program update section,

[0162] 230 force control section,

[0163] 240 actual trajectory acquisition section,

[0164] 250 trajectory correction parameter calculation section,

[0165] 30 workpiece.

Claims

1. A burr removal apparatus comprising a burr removal robot manipulator for removing burrs from an object, characterized in that, The burr removal device includes: The robot program generation department pre-generates robot programs for burr removal. The burr removal area detection unit detects the position of the burr removal area of ​​a workpiece that is the object of the document using a vision sensor. The robot program update unit updates the robot program based on the position of the burr removal part of the workpiece that is the object, as obtained by the burr removal part detection unit. The force control unit detects the force acting on the robot manipulator and a workpiece that becomes the object, and controls it in a predetermined pressing manner. The actual trajectory acquisition unit acquires the actual trajectory of the robot manipulator's action when the force control unit controls the robot manipulator to the predetermined pressing force based on the data output by the position sensor and the robot program updated by the robot program update unit. as well as The trajectory correction parameter calculation unit calculates correction parameters related to the position of the burr removal area of ​​a workpiece, as detected by the vision sensor, when the force control unit controls the robot manipulator to apply the predetermined pressing force, and the actual trajectory. The calculation is performed in a manner that either makes the point sequence of the robot manipulator's motion trajectory match the point sequence of the actual trajectory, or makes the point sequence of the actual trajectory match the point sequence of the robot manipulator's motion trajectory. The robot program update unit also updates the robot program based on the corrected position of the burr removal area. This corrected position is obtained by correcting the positions of the burr removal areas of other workpieces that are the target objects, as detected by the burr removal area detection unit, using the correction parameters calculated by the trajectory correction parameter calculation unit. The force control unit also detects the forces acting on the robot manipulator and other workpieces that become the object, based on the robot program updated by the robot program update unit, and controls them in a manner that becomes the predetermined pressing pressure.

2. The burr removal device according to claim 1, characterized in that, The correction parameters calculated by the trajectory correction parameter calculation unit are reflected in the detection results of the burr removal area detection unit based on the vision sensor.

3. The burr removal device according to claim 1, characterized in that, The correction parameters calculated by the trajectory correction parameter calculation unit are reflected in the mechanism parameters of the robot manipulator.

4. The burr removal apparatus according to any one of claims 1 to 3, characterized in that, If the residual between the robot manipulator's motion trajectory, as calculated by the calculated correction parameters and the actual trajectory, exceeds a predetermined value, the trajectory correction parameter calculation unit divides the robot manipulator's motion trajectory and the actual trajectory detected by the vision sensor into multiple intervals, and calculates the correction parameters for each of the multiple intervals.

5. A control system for a robot comprising a workpiece, characterized in that, The control system includes: The generation unit pre-generates motion programs that enable the robot to perform actions. The inspection department uses a vision sensor to detect one workpiece that becomes the object. The updating unit updates the action program based on the detection result of one workpiece that is the object obtained by the detection unit; The control unit controls the robot's processing actions on a workpiece that becomes the object, based on the action program updated by the update unit. The acquisition unit acquires the actual trajectory of the robot's processing action when controlled by the control unit, based on data output from the position sensor and the action program updated by the update unit. as well as The calculation unit, based on the trajectory of the robot's machining motion detected by the detection unit during control by the control unit and the actual trajectory, calculates correction parameters related to the detection result of a workpiece that is the target object, as detected by the detection unit, in a manner that makes the point sequence of the robot's machining motion trajectory consistent with the point sequence of the actual trajectory, or makes the point sequence of the actual trajectory consistent with the point sequence of the robot's machining motion trajectory. The updating unit further updates the action program based on the corrected detection results, which are obtained by correcting the detection results of other workpieces that are the target objects detected by the detection unit using the correction parameters calculated by the calculation unit. The control unit also controls the robot's processing actions on other workpieces that become the target objects based on the action program updated by the update unit.

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