Method and system for adaptive tracking of a spot laser to correct actual topography detection path

Abstract

The application provides a kind of point laser adaptive tracking correction actual topography detection path method and system, contain actuator, laser, end execution tool, camera, include the following steps: 3D point cloud data of target object surface is collected to generate walking path and pose set A in first coordinate system;Pose set A is converted into actuator end motion trajectory B in first coordinate system;Actuator end walks along actuator end motion trajectory B, obtains the distance between laser and target object surface, generates walking path and pose set E in first coordinate system;Convert out actuator end motion trajectory F in first coordinate system;Actuator end walks along actuator end motion trajectory F;The application can be adaptively tracked and corrected according to actual topography Path, correct actuator end motion trajectory, always let end execution tool and target object surface keep suitable working distance.

Description

Technical Field

[0001] This invention belongs to the field of robot path planning, and in particular relates to a method and system for point laser adaptive tracking correction of actual shape detection path. Background Technology

[0002] Industrial robot systems, such as plasma cutting robots, combine plasma cutting technology with the automation and precision of robotics. The robot drives the plasma cutting tool along a planned path, providing an efficient and precise cutting solution for modern industrial manufacturing. Plasma cutting has high distance requirements; excessive distance can cause the plasma torch to break its arc, while insufficient distance may lead to torch collisions, affecting tool life and cutting progress. In actual cutting operations, to avoid uneven surfaces causing the torch to move inconsistently between the cutting surface and the cutting head, affecting the cutting effect, laser sensors are often added to the robot. The robot control system automatically adjusts the cutting head height based on sensor feedback to adapt to the unevenness of the material surface. For example, the laser cutting coordinate adjustment interpolation method disclosed in patent document CN118951398A monitors the cutting position in real time and adjusts the cutting head height according to the height of the pipe cutting position.

[0003] The aforementioned existing technologies suffer from delayed response. If the robot moves at a high speed, and the speed at which the sensors measure distance and feed it back to the control system cannot keep up with the cutting speed, a delay may occur, leading to a collision. In some high-speed applications, the sensors may not be able to detect changes in the surface undulations in time.

[0004] Adjusting the sensor's measurement direction is a feasible solution. For example, the sensor can be set to deflect at a certain angle in the direction of travel, so as to obtain the height and position information of the target point in advance before the end tool reaches the target position, thereby allowing time for the robot to adjust its path. However, there are drawbacks: the sensor can only measure the distance in a single direction, which means that this predictive path adjustment method is only applicable to the walking path that moves along the direction deflected by the sensor, and will be subject to many limitations in practical applications. Summary of the Invention

[0005] This invention aims to solve the above problems and provides a method and system for adaptive tracking and correction of the actual shape detection path using point laser. The method adaptively tracks the end-effector motion trajectory of the actual shape correction actuator. During the actual task execution, the end-effector motion trajectory is controlled to drive the end-effector tool to walk along the corrected walking path and posture, so that the end-effector tool always maintains a suitable working distance from the surface of the target object.

[0006] The present invention addresses the problem by employing the following technical solution: a method for point laser adaptive tracking and correction of the actual shape detection path, comprising an actuator, a laser, an end effector, and a camera. The laser and the end effector are rigidly mounted at the end of the actuator. The laser is used to obtain the distance between the laser projection origin and the surface of the target object. The laser and the end effector move under the drive of the actuator. The method includes the following steps:

[0007] S1 activates the camera to acquire 3D point cloud data of the target object's surface;

[0008] S2 Based on the 3D point cloud data collected in step S1 and the preset process requirements, the path planning module generates a walking path and pose set A{A1,A2......A1} in the first coordinate system. n}, i=1,2......n;

[0009] Pose AI includes position coordinates and orientation. norm m The preset process requirements include the preset working posture of the end effector and the preset working distance d. m1 ;

[0010] S3 uses the transformation relationship H1 between the laser and the coordinate system of the actuator end effector, and the preset travel distance d of the laser, to achieve this. m2 The pose set A is transformed into the end effector motion trajectory B{B1,B2......B1} in the first coordinate system. n The preset walking distance d m2 It is the preset collision avoidance distance or safety distance; B i = (A i +ABS norm m *d m2 )*H1;

[0011] S4 controls the actuator to drive the actuator end along the actuator end motion trajectory B, so that the laser emission origin of the laser moves along the path and the pose set C{C1,C2......C n Walking; (A) i +ABS norm m *d m2 ) represents the laser path C i ; Obtain the laser's pose C i The distance d between the laser and the surface of the target object i ;

[0012] S5 Based on the distance d iThe preset working distance requirement d m1 The difference is compensated, and the pose A is adjusted. i For position E i Generate the walking path and pose set E{E1,E2......E} in the first coordinate system. n};E i =A i +ABS norm m *(d m2 +d m1 -d i );

[0013] S6 transforms the travel path and pose set E into the motion trajectory F{F1,F2......F... of the actuator end effector in the first coordinate system through the transformation relationship H2 between the end effector and the actuator end effector coordinate system. n};

[0014] S7 controls the actuator to drive the actuator end effector to move along the actuator end effector trajectory F, so that the end effector tool moves along the walking path and the pose set E{E1,E2......E n}walk.

[0015] The first coordinate system is the base coordinate system of the actuator.

[0016] Between step S5 and step S6, the following steps are also included:

[0017] Return the generated walking path and pose set E as the new walking path and pose set A to step S3. Based on the new walking path and pose set A, obtain the new actuator end effector trajectory B, the new laser emission origin along the path and pose set C, and the new distance d according to steps S3~S4. i ;

[0018] Calculate the new distance d i With d m2 +d m1 The relationship between them:

[0019] If ABS(d) m2 +d m1 -d i If the value of the walking path and pose set E is less than or equal to the first threshold, then the walking path and pose set E will be used as the final end-effector walking path and pose set of the end-effector, and the process will proceed to step S6.

[0020] If ABS(d) m2 +d m1 -d iIf the threshold is greater than the first threshold, proceed to step S5 and generate a new walking path and pose set E according to step S5. Repeat the above steps until step S6 is reached.

[0021] The transformation relationship between the laser and the end coordinate system of the actuator mentioned in step S3 is obtained through prior calibration.

[0022] The transformation relationship between the laser and the coordinate system of the actuator end effector is pre-calibrated using the following method:

[0023] Sa1 sets a marker point TA on the laser projection plate;

[0024] Sa2 controls the actuator to drive the laser to move through the end of the actuator, so that the laser point projected by the laser falls on the marked point TA, which is the initial position P0. Record the coordinates Q0 of the center point of the end of the actuator in the second coordinate system at this time, as well as the transformation matrix H0 between the coordinate system of the end of the actuator and the second coordinate system.

[0025] Sa3 controls the actuator to move the laser to M different positions P via the actuator's end. j (j=1, 2, ..., M), M≥1, at each position P j (j≥1) Keep the laser projection on the marked point TA; record the translation to the corresponding position P. j When (j≥1), the coordinates Q of the end effector center in the second coordinate system are... j (j≥1), and the transformation matrix H between the actuator end coordinate system and the second coordinate system. j (j≥1);

[0026] Sa4 is based on the set of center coordinates of the actuator's end effector Q{Q j |j≥0}, the laser projection direction of the laser in the second coordinate system is obtained by fitting. norm 1 ;

[0027] Sa5 combined with H j The rotation matrix in the equation is used to obtain the direction of the laser projection direction in the coordinate system of the actuator end effector. norm 2 ；

[0028] Sb1 sets a marker point TB on the laser projection plate;

[0029] Sb2 controls the actuator to adjust the attitude and position of the end effector so that the laser point projected by the laser falls on the marker point TB, and obtains the distance d between the origin of the laser projection and the marker point TB when the laser falls on the marker point TB, and obtains the coordinates W of the marker point TB in the current coordinate system of the end effector.

[0030] Sb3 according to the direction norm 2 Given distance d and coordinate W, calculate the coordinates QS of the laser projection origin in the actuator end-effector coordinate system; based on the direction... norm 2 By using the coordinates QS of the laser projection origin in the actuator end coordinate system, the transformation relationship H1 between the laser and the actuator end coordinate system is obtained.

[0031] The S2 step also includes: fitting a reference target plane M using the 3D point cloud data collected in the S1 step.

[0032] The laser projection direction of the laser is consistent with the extension direction of the end effector; the distance g between the laser emission origin and the actuating end of the end effector in the extension direction of the end effector is known; the distance d is measured in step S4. i Then, based on the distance d i Distance g and preset working requirement distance d m1 The relationship is adjusted so that the end effector's trajectory is Bw{Bw1,Bw2......Bw}. n}, causing the laser emission origin to move along Cw; Bw i =B i +ABS norm m *(d m1 +gd i ).

[0033] The following method is used to make the end effector of the end effector move along the path and pose set E: control the end effector of the actuator to move along the path and pose set E.

[0034] The following method is used to make the end effector of the end effector travel along the path and pose set E: when the end effector's motion trajectory is Bw, obtain the virtual point L at a distance g from the laser origin in the laser projection direction. i According to virtual point L i Based on the relative positional deviation of the end effector with respect to the end effector, the motion trajectory of the end effector corresponding to the path and pose set E along which the end effector moves is calculated.

[0035] A system for adaptive tracking and correction of the actual shape detection path using point laser, comprising the method described above, including:

[0036] Executive agency;

[0037] The laser is rigidly mounted at the end of the actuator;

[0038] An end effector is rigidly mounted at the end of the actuator.

[0039] A camera used to acquire 3D point cloud data of the surface of a target object;

[0040] The path planning module generates walking paths and pose sets.

[0041] The control system controls the actuator to move its end effector.

[0042] The data processing module is used for data processing and calculation.

[0043] The beneficial effects of this invention are as follows: By acquiring information about the surface of the target object through a camera, a theoretical walking path and pose set are generated according to preset requirements, and further converted into the motion trajectory of the end effector. Under the drive of the end effector, the laser moves along a specific path, and the distance data between the laser and the surface of the target object is obtained. Based on the data results, the walking path and pose set are corrected, and the motion trajectory of the end effector corresponding to the end effector when moving along the corrected walking path and posture is calculated according to the transformation relationship between different coordinate systems. The path is adaptively tracked and corrected according to the actual shape, thereby controlling the motion trajectory of the end effector during the actual working process, driving the end effector to move along the corrected walking path and posture, and always keeping the end effector at a suitable working distance from the surface of the target object, ensuring both safety and work quality. Attached Figure Description

[0044] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0045] Figure 1 This is a flowchart of the present invention;

[0046] Figure 2 This is a schematic diagram of the implementation environment of the present invention;

[0047] Figure 3 This is a schematic diagram illustrating the implementation environment from another perspective of the present invention;

[0048] Figure 4 This is a schematic diagram illustrating the preset working requirements in this invention;

[0049] Figure 5 This is a schematic diagram of parameter g in this invention;

[0050] Figure 6 This is an explanatory diagram illustrating the method for adjusting the path of the terminal execution tool in this invention;

[0051] Figure 7 This is a schematic diagram of the virtual point Li in this invention. Detailed Implementation

[0052] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0053] A system for implementing a point laser adaptive tracking correction method for actual topography detection path, such as Figure 2 As shown, the device includes an actuator 1, a laser 2, an end effector 3, and a camera 4. The laser 2 and the end effector 3 are rigidly mounted at the end of the actuator. The laser 2 and the end effector 3 are used to obtain the distance between the laser projection origin and the surface 5 of the target object. The laser 2 and the end effector 3 move under the drive of the actuator 1. Figure 3 As shown, the surface 5 of the target object has a certain degree of unevenness.

[0054] The actuator 1 can be a robotic arm, a robotic hand, or other device with similar functions. In a specific embodiment, a robotic arm is used as the actuator, and the laser is rigidly mounted on the flange at the end of the robotic arm.

[0055] The end-effector 3 can be a cutting torch, welding torch, spray gun, or other similar tool.

[0056] Camera 4 can be mounted on actuator 1 or on other platforms; it is used to collect 3D point cloud data of the target object surface.

[0057] The system also includes:

[0058] The path planning module is used to generate walking paths and pose sets;

[0059] The control system controls the actuator to move its end effector.

[0060] The data processing module is used for data processing and calculation.

[0061] Before the system can operate, the following information needs to be imported:

[0062] Preset process requirements, including preset actuator working posture and preset working distance d. m1 ;

[0063] Preset walking distance d m2This refers to the preset anti-collision distance or safety distance;

[0064] Taking a cutting torch as an end effector as an example, the preset process requirements include the orientation of the cutting torch during actual operation, and the distance between the origin of the cutting torch head and the point to be cut on the surface of the target object. For example... Figure 4 As shown, the wavy line represents the uneven surface of the object to be cut, the arrow indicates the cutting torch, and the arrowhead indicates the origin of the cutting torch head. The working distance between the cutting torch head and the surface of the object to be cut is a preset value, and the cutting posture of the torch head is a preset posture, which can generally be set to be perpendicular to the surface of the object to be cut. Based on the preset cutting distance and preset cutting posture, combined with the approximate unevenness of the surface of the object to be cut obtained from 3D point cloud acquisition, the approximate travel path and posture set of the cutting torch can be generated.

[0065] To prevent the laser, cutting torch head, or other components from colliding with the target surface when the actuator moves the laser, a certain safety distance needs to be set. The safety distance is set according to the actual situation.

[0066] In a specific embodiment, such as Figure 5 As shown, the laser is mounted on a cutting torch, which is rigidly mounted on the flange of the robotic arm. The laser projection direction is basically consistent with the extension direction of the cutting torch head. The distance between the laser emission origin and the origin of the cutting torch head in the extension direction of the cutting torch head is g. If the laser is allowed to travel along the path and pose set A, the cutting torch head will collide with the target object. To avoid the cutting torch head colliding during the movement of the robotic arm carrying the laser, a safety distance d greater than g can be set. m2 .

[0067] If there are large protrusions on the surface of the target object, try to increase the safe distance.

[0068] A method for point laser adaptive tracking and correction of the actual topography detection path, such as... Figure 1 As shown, it includes the following steps:

[0069] S1 activates the camera to acquire 3D point cloud data of the target object's surface; based on the acquired 3D point cloud data, the approximate unevenness of the target object's surface can be generated; (The rest of the text appears to be a fragment and requires further context for accurate translation.) Figure 6 The surface of the actual uneven target object shown in Figure 1 is reconstructed in 3D to restore the approximate degree of unevenness, such as... Figure 6 As shown in .2;

[0070] S2, based on the 3D point cloud data collected in step S1 and the preset process requirements, generates a walking path and pose set A{A1,A2......A2} in the first coordinate system through the path planning module. n}, i=1,2...n, such as Figure 6 As shown in .3;

[0071] AI includes position coordinates and orientation norm. m ; Figure 6 .3 A simplified illustration of the attitude direction norm m In practice, different attitude directions can be set according to the surface conditions of the target object. For example, for each target point, the attitude direction can be set to be perpendicular to the tangent at that point.

[0072] Preset process requirements include the preset working posture of the end effector and the preset working distance d. m1 Based on 3D point cloud data and preset process requirements, generate the expected end-effector travel path and pose set A;

[0073] S3 uses the transformation relationship H1 between the laser and the actuator end coordinate system, and the preset travel distance d of the laser, to determine the required distance. m2 Transform the pose set A into the end effector motion trajectory B{B1,B2......B1} in the first coordinate system. n};Preset walking distance d m2 It is the preset collision avoidance distance or safety distance; B i = (A i +ABS norm m *d m2 )*H1;

[0074] ABS norm m The direction away from the surface of the target object. norm m When the direction is away from the target surface, it is the same direction; when the direction is close to the target surface, it is the opposite direction after rotating 180°.

[0075] S4 controls the actuator to move its end effector along the trajectory B of the actuator end effector, so that the laser emission origin of the laser moves along the path and the pose set C{C1,C2......C n Walking as Figure 6 As shown in .3; (A) i +ABS norm m *d m2 ) represents the laser path C i ; Obtain the laser's pose C i The distance d between the laser and the surface of the target object i ;like Figure 6 As shown in .4;

[0076] S5 Based on distance d i The preset working distance requirement d m1 Relationship, adjust Ai For position E i Generate the walking path and pose set E{E1,E2......E} in the first coordinate system. n};like Figure 6 As shown in Figure 5;

[0077] Compensation is performed based on the difference to obtain E. i =A i +ABS norm m *(d m2 +d m1 -d i )

[0078] S6 transforms the pose set E into the motion trajectory F{F1,F2......F2} of the actuator end effector in the first coordinate system through the transformation relationship H2 between the end effector tool and the end effector coordinate system. n};

[0079] S7 controls the actuator to drive the end effector along the end effector trajectory F, so that the end effector of the tool moves along the path and the pose set E{E1,E2......E n}walk.

[0080] In one embodiment, the first coordinate system can be selected as the actuator base coordinate system.

[0081] In another embodiment, the first coordinate system described above is selected as the world coordinate system.

[0082] Between steps S5 and S6, there are the following steps that can verify the generated walking path and pose set E:

[0083] Return the generated walking path and pose set E as the new walking path and pose set A to step S3. Based on the new walking path and pose set A, obtain the new actuator end effector trajectory B, the new laser emission origin along the path and pose set C, and the new distance d according to steps S3~S4. i ;

[0084] Calculate the new distance d i With d m2 +d m1 The relationship between them:

[0085] If ABS(d) m2 +d m1 -d i If the value is less than or equal to the first threshold, then the walking path and pose set E will be used as the final end-effector walking path and pose set; proceed to step S6.

[0086] If ABS(d) m2 +d m1 -d i If the distance between the laser and the target surface exceeds the first threshold, proceed to step S5. Generate a new walking path and pose set E according to step S5. Use the new walking path and pose set E as the final end effector's walking path and pose set, and proceed to step S6. Alternatively, repeat the above steps until the distance between the laser and the target surface is equal to d when the actuator drives the end effector to walk along the end effector's motion trajectory. m2 +d m1 If the absolute value of the difference between them is less than or equal to the first threshold, proceed to step S6.

[0087] The specific implementation is as follows: For the walking path and pose set E obtained in step S5, the transformation relationship H1 between the laser and the end effector coordinate system, and the preset walking distance d of the laser, are used... m2 The pose set E is transformed into the end effector trajectory B'{B'1,B'2......B'} in the first coordinate system. n};

[0088] B' i =(E i +ABS norm m *d m2 )*H1;

[0089] The control actuator drives the actuator end effector to move along the actuator end effector trajectory B', so that the laser emission origin of the laser moves along the path and the pose set C'{C'1,C'2......C'}. n Walking; (E) i +ABS norm m *d m2 Let C'i be the laser path; obtain the laser's pose C'. i The distance d' between the laser and the target surface i ;

[0090] Calculate d' i With d m2 +d m1 The relationship between them:

[0091] If ABS(d) m2 +d m1 -d' i If the set E is less than or equal to the first threshold, then set E is taken as the final end-effector's travel path and pose set; through the transformation relationship H2 between the end-effector and the actuator's end-effector coordinate system, the pose set E is transformed into the actuator's end-effector motion trajectory F{F1,F2......F2} in the first coordinate system.n}; The control actuator drives the end effector to move along the end effector trajectory F, so that the end effector of the tool moves along the path and the pose set E{E1,E2......E n}walk.

[0092] If ABS(d) m2 +d m1 -d' i If E > the first threshold, then adjust E. i For position E' i Generate the walking path and pose set E'{E'1,E'2......E'} in the first coordinate system. n};

[0093] Compensation is performed based on the difference to obtain E' i =E i +ABS norm m *(d m2 +d m1 -d' i );

[0094] The obtained set E' can be used as the final end-effector's travel path and pose set; or the above steps can be repeated, and the obtained set E' can be used again through the transformation relationship H1 between the laser and the end-effector coordinate system, and the laser's preset travel distance d. m2 The pose set E' is transformed into the motion trajectory B'' of the actuator end effector in the first coordinate system. The actuator is controlled to move along the motion trajectory B'', so that the laser emission origin of the laser moves along the path and the pose set C''; the laser's position at pose C'' is obtained. i The distance d'' between the laser and the target surface i Compare d'' i With d m2 +d m1 The relationship between them; if ABS(d m2 +d m1 -d'' i If the value of E' is less than or equal to the first threshold, then the set E' will be used as the final execution path and pose set of the final end-effector tool.

[0095] If ABS(d) m2 +d m1 -d'' i If the distance between the laser and the target surface exceeds the first threshold, adjust again using the above steps until the distance between the laser and the target surface is equal to d when the actuator moves along the trajectory of the actuator end. m2 +dm1 If the absolute value of the difference between them is less than or equal to the first threshold, the final execution path and pose set of the terminal execution tool can be obtained.

[0096] The transformation relationship H1 between the laser and the coordinate system of the actuator end effector can be calculated using assembly parameters, with the installation position and direction of the laser as the basis for calculating H1.

[0097] In real-world scenarios, assembly errors can cause H1 to deviate from the calculated value. One feasible way to reduce these errors is to obtain the transformation relationship between the laser and the end effector coordinate system through pre-calibration.

[0098] A method for calibrating the position of a laser in the coordinate system of the actuator end effector is provided:

[0099] Sa1 places a flat laser projection plate in the environment. The laser line projected by the laser can fall on the laser projection plate to form a laser point. A mark point TA is set on the laser projection plate.

[0100] Sa2 controls the actuator to move the laser by the end of the actuator, so that the laser point projected by the laser falls on the marked point TA. This position is the initial position P0. Record the coordinates Q0 of the center point of the end of the actuator in the second coordinate system, as well as the transformation matrix H0 between the coordinate system of the end of the actuator and the second coordinate system.

[0101] Sa3 controls the actuator to move the laser to M different positions P via the actuator's end. j (j=1, 2, ..., M), M≥1, at each position P j (j≥1) Keep the laser projection on the marked point TA; record the translation to the corresponding position P. j When (j≥1), the coordinates Q of the end effector center in the second coordinate system are... j (j≥1), and the transformation matrix H between the actuator end coordinate system and the second coordinate system. j (j≥1);

[0102] Sa4 is based on the set of center coordinates of the actuator's end effector Q{Q j |j≥0}, the laser projection direction of the laser in the second coordinate system is obtained by fitting. norm 1 ;

[0103] Sa5 combined with H j The rotation matrix in the equation is used to obtain the direction of the laser projection direction in the coordinate system of the actuator end effector. norm 2 ；

[0104] Sb1 sets a marker point TB on the laser projection plate;

[0105] Sb2 controls the actuator to adjust the attitude and position of the end effector so that the laser point projected by the laser falls on the marker point TB. It obtains the distance d between the origin of the laser projection and the marker point TB when the laser point falls on the marker point TB, and obtains the coordinates W of the marker point TB in the current coordinate system of the actuator end effector.

[0106] Sb3 calculates the coordinates QS of the laser projection origin in the coordinate system of the actuator end effector based on the laser direction norm2, distance d, and coordinate W;

[0107] Based on laser projection direction norm 2 By using the coordinates QS of the laser projection origin in the actuator end coordinate system, the transformation relationship H1 between the laser and the actuator end coordinate system can be obtained.

[0108] The second coordinate system in the above process is the base coordinate system of the actuator;

[0109] Alternatively, a virtual coordinate system can be used, which is the coordinate system of the actuator end point when the actuator moves the laser to the initial position P0.

[0110] In one embodiment, the base coordinate system of the actuator is selected as the second coordinate system, and the robotic arm is selected as the actuator.

[0111] For a robotic arm, the actuator base coordinate system is the same as the robotic arm base coordinate system, the actuator end coordinate system refers to the flange coordinate system, and the actuator end center refers to the flange center.

[0112] The robotic arm moves the laser to P0, P1, P2, P3...P M At that time, the corresponding coordinates of the flange center in the base coordinate system are Q0, Q1, Q2, Q3...Q M For points Q0, Q1, Q2, Q3...Q M The fitting process is performed, and the direction of the straight line obtained is the direction of the laser projection direction in the second coordinate system, that is, the base coordinate system of the robotic arm. norm 1 The direction norm1 can be taken as the unit vector of the fitted straight line direction.

[0113] The robotic arm moves the laser to P0, P1, P2, P3...P M At that time, the transformation matrices between the flange coordinate system and the robot arm base coordinate system are H0, H1, H2, H3...H M For any transformation matrix H j(j≥0), including rotation matrix and translation vector, combined with H j The rotation matrix and the direction of laser projection in the first coordinate system norm 1 ， The direction of the laser projection in the flange coordinate system is calculated. norm 2 .

[0114] One method for obtaining the coordinates W of the marker point TB in the current actuator end effector coordinate system:

[0115] Record the coordinates of marker point TB in the third coordinate system;

[0116] Record the transformation matrix H between the third coordinate system and the current actuator end effector coordinate system. T ;

[0117] Combine H T Given the coordinates of the marker point TB in the third coordinate system, obtain the coordinates W of the marker point TB in the current actuator end coordinate system.

[0118] The third coordinate system is the base coordinate system of the actuator;

[0119] Or the workpiece coordinate system.

[0120] In step S1, the approximate unevenness of the target object's surface is generated based on the acquired 3D point cloud data. In a special case, when the unevenness of the target object's surface is relatively small or the tolerance range of pose is large, it can be modified to fit a plane based on the acquired 3D point cloud data. Based on the fitted plane and combined with preset process requirements, the path planning module generates the walking path and pose set A in the first coordinate system.

[0121] In one specific embodiment, the laser is mounted on the end effector, and the laser projection direction of the laser is set to be consistent with the extension direction of the end effector, without considering the difference in direction between the two due to assembly errors.

[0122] Adjust the terminal execution tool path using the following steps:

[0123] S1 activates the camera to collect 3D point cloud data of the target object's surface;

[0124] S2, based on the 3D point cloud data collected in step S1 and the preset process requirements, generates a walking path and pose set A{A1,A2......A2} in the first coordinate system through the path planning module. n}, i=1,2......n;

[0125] AI includes position coordinates and orientation norm. m ;

[0126] Preset process requirements include the preset working posture of the end effector and the preset working distance d. m1 ;

[0127] S3 uses the transformation relationship H1 between the laser and the actuator end coordinate system, and the preset travel distance d of the laser, to determine the required distance. m2 Transform the pose set A into the end effector motion trajectory B{B1,B2......B1} in the first coordinate system. n};Preset walking distance d m2 It is the preset anti-collision distance or safety distance;

[0128] B i = (A i +ABS norm m *d m2 )*H1

[0129] ABS norm m The direction away from the surface of the target object. norm m When the direction is away from the target surface, it is the same direction; when the direction is close to the target surface, it is the opposite direction after rotating 180°.

[0130] S4 controls the actuator to move its end effector along the trajectory B of the actuator end effector, so that the laser emission origin of the laser moves along the path and the pose set C{C1,C2......C n Walking; (A) i +ABS norm m *d m2 ) represents the laser path C i ; Obtain the laser's pose C i The distance d between the laser and the surface of the target object i ;

[0131] S5 Based on distance d i Distance g and preset working requirement distance d m1 The relationship is such that the end-effector trajectory is adjusted to Bw, and when the end-effector trajectory is Bw, the laser emission origin moves along Cw.

[0132] Bw i =B i +ABS norm m *(d m1 +gd i ), refers to the actuator end effector from attitude B i Start along ABS norm m direction Move (d) m1 +gd i Posture after )

[0133] The distance measured when the laser emission origin travels along Cw is (d m1 +g);

[0134] Generate the walking path and pose set E{E1,E2......E} in the first coordinate system. n}, (Cw i -ABS norm m *g) represents the walking path and pose E in the first coordinate system. i ;

[0135] Without considering the positional deviation between the laser and the end effector, assuming that the laser line and the end effector are on the same straight line, then in actual operation, let the end motion trajectory of the actuator be Bw, which will drive the end effector to move along the path and pose set E of the end effector.

[0136] Considering the positional deviation between the laser and the end effector, the laser line and the end effector are necessarily not on the same straight line. When the end effector's trajectory is Bw, the laser emission origin travels along Cw, as shown below. Figure 7 As shown, a virtual point L is located at a distance g from the laser origin along the laser projection direction. i These are the coordinates of Ei, based on the virtual point L. i Based on the relative positional deviation of the end effector with respect to the end effector, the motion trajectory of the end effector corresponding to the path and pose set E along which the end effector moves is calculated.

[0137] Taking a cutting gun as an example, the execution end of an end-effector refers to the tip of the gun head.

[0138] Compared with existing technologies, the present invention has the following advantages: by acquiring information about the surface of the target object through a camera, a theoretical walking path and pose set are generated according to preset requirements, and further converted into the motion trajectory of the end effector. Under the drive of the end effector, the laser moves along a specific path, and the distance data between the laser and the surface of the target object is obtained. Based on the data results, the walking path and pose set are corrected, and according to the transformation relationship between different coordinate systems, the motion trajectory of the end effector corresponding to the end effector when it moves along the corrected walking path and posture is calculated. The path is adaptively tracked and corrected according to the actual shape, so that in the formal working process, the motion trajectory of the end effector is controlled, and the end effector moves along the corrected walking path and posture, always keeping the end effector at a suitable working distance from the surface of the target object, ensuring both safety and work quality.

[0139] Furthermore, it should be understood that the above embodiments only illustrate several implementation methods of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the invention patent. It should be pointed out that those skilled in the art can make several modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention.

Claims

1. A method for point laser adaptive tracking and correction of an actual shape detection path, comprising an actuator, a laser, an end effector, and a camera, wherein the laser and the end effector are rigidly mounted at the end of the actuator, the laser is used to obtain the distance between the laser projection origin and the surface of the target object, and the laser and the end effector move under the drive of the actuator; characterized in that, Includes the following steps: S1 activates the camera to acquire 3D point cloud data of the target object's surface; S2 Based on the 3D point cloud data collected in step S1 and the preset process requirements, the path planning module generates a walking path and pose set A{A1,A2......A1} in the first coordinate system. n }, i=1,2......n; Pose AI includes position coordinates and orientation. norm m The preset process requirements include the preset working posture of the end effector and the preset working distance d. m1 ; S3 uses the transformation relationship H1 between the laser and the coordinate system of the actuator end effector, and the preset travel distance d of the laser, to achieve this. m2 The pose set A is transformed into the end effector motion trajectory B{B1,B2......B1} in the first coordinate system. n The preset walking distance d m2 It is the preset collision avoidance distance or safety distance; B i = (A i +ABS norm m *d m2 )*H1; S4 controls the actuator to drive the actuator end along the actuator end motion trajectory B, so that the laser emission origin of the laser moves along the path and pose set C{C1,C2......C n Walking; (A) i +ABS norm m *d m2 ) represents the laser path C i ; Obtain the laser's pose C i The distance d between the laser and the surface of the target object i ; S5 Based on the distance d i The preset working distance requirement d m1 The difference is compensated, and the pose A is adjusted. i For position E i Generate the walking path and pose set E{E1,E2......E} in the first coordinate system. n };E i =A i +ABS norm m *(d m2 +d m1 -d i ); S6 transforms the travel path and pose set E into the motion trajectory F{F1,F2......F... of the actuator end effector in the first coordinate system through the transformation relationship H2 between the end effector and the actuator end effector coordinate system. n }; S7 controls the actuator to drive the actuator end effector to move along the actuator end effector trajectory F, so that the end effector tool moves along the walking path and the pose set E{E1,E2......E n }walk.

2. The method for point laser adaptive tracking and correction of the actual shape detection path as described in claim 1, characterized in that, The first coordinate system is the base coordinate system of the actuator.

3. The method for point laser adaptive tracking and correction of the actual shape detection path as described in claim 1, characterized in that, Between step S5 and step S6, the following steps are also included: The generated walking path and pose set E is used as the new walking path and pose set A. Returning to step S3, based on the new walking path and pose set A, steps S3-S4 are followed to obtain the new actuator end effector trajectory B, the new laser emission origin along the path and pose set C, and the new distance d. i ; Calculate the new distance d i With d m2 +d m1 The relationship between them: If ABS(d) m2 +d m1 -d i If the value of the walking path and pose set E is less than or equal to the first threshold, then the walking path and pose set E will be used as the final end-effector walking path and pose set of the end-effector, and the process will proceed to step S6. If ABS(d) m2 +d m1 -d i If the threshold is greater than the first threshold, proceed to step S5 and generate a new walking path and pose set E according to step S5. Repeat the above steps until step S6 is reached.

4. The method for point laser adaptive tracking and correction of the actual shape detection path as described in claim 1, characterized in that, The transformation relationship between the laser and the end coordinate system of the actuator mentioned in step S3 is obtained through prior calibration.

5. The method for point laser adaptive tracking and correction of the actual shape detection path as described in claim 4, characterized in that, The transformation relationship between the laser and the coordinate system of the actuator end effector is pre-calibrated using the following method: Sa1 sets a marker point TA on the laser projection plate; Sa2 controls the actuator to drive the laser to move through the end of the actuator, so that the laser point projected by the laser falls on the marked point TA, which is the initial position P0. Record the coordinates Q0 of the center point of the end of the actuator in the second coordinate system at this time, as well as the transformation matrix H0 between the coordinate system of the end of the actuator and the second coordinate system. Sa3 controls the actuator to move the laser to M different positions P via the actuator's end. j (j=1, 2, ..., M), M≥1, at each position P j (j≥1) Keep the laser projection on the marked point TA; record the translation to the corresponding position P. j When (j≥1), the coordinates Q of the end effector center in the second coordinate system are... j (j≥1), and the transformation matrix H between the actuator end coordinate system and the second coordinate system. j (j≥1); Sa4 is based on the set of center coordinates of the actuator's end effector Q{Q j |j≥0}, the laser projection direction of the laser in the second coordinate system is obtained by fitting. norm 1 ; Sa5 combined with H j The rotation matrix in the equation is used to obtain the direction of the laser projection direction in the coordinate system of the actuator end effector. norm 2 ； Sb1 sets a marker point TB on the laser projection plate; Sb2 controls the actuator to adjust the attitude and position of the end effector so that the laser point projected by the laser falls on the marker point TB, and obtains the distance d between the origin of the laser projection and the marker point TB when the laser falls on the marker point TB, and obtains the coordinates W of the marker point TB in the current coordinate system of the end effector. Sb3 according to the direction norm 2 Given distance d and coordinate W, calculate the coordinates QS of the laser projection origin in the actuator end-effector coordinate system; based on the direction... norm 2 By using the coordinates QS of the laser projection origin in the actuator end coordinate system, the transformation relationship H1 between the laser and the actuator end coordinate system is obtained.

6. The method for point laser adaptive tracking and correction of the actual shape detection path as described in claim 1, characterized in that, The S2 step also includes: fitting a reference target plane M using the 3D point cloud data collected in the S1 step.

7. The method for point laser adaptive tracking and correction of the actual shape detection path as described in claim 1, characterized in that, The laser projection direction of the laser is consistent with the extension direction of the end effector; the distance g between the laser emission origin and the execution end of the end effector in the extension direction of the end effector is known. The distance d is measured in step S4. i Then, based on the distance d i Distance g and preset working requirement distance d m1 The relationship is adjusted so that the end effector's trajectory is Bw{Bw1,Bw2......Bw}. n }, causing the laser emission origin to move along Cw; Bw i =B i +ABS norm m *(d m1 +gd i ).

8. The method for point laser adaptive tracking and correction of the actual shape detection path as described in claim 7, characterized in that, The following method is used to make the end effector of the end effector move along the path and pose set E: control the end effector of the actuator to move along the path and pose set E.

9. The method for point laser adaptive tracking and correction of the actual shape detection path as described in claim 7, characterized in that, The following method is used to make the end effector of the end effector travel along the path and pose set E: when the end effector's motion trajectory is Bw, obtain the virtual point L at a distance g from the laser origin in the laser projection direction. i According to virtual point L i Based on the relative positional deviation of the end effector with respect to the end effector, the motion trajectory of the end effector corresponding to the path and pose set E along which the end effector moves is calculated.

10. A system for point laser adaptive tracking and correction of the actual shape detection path, characterized in that, The method for point laser adaptive tracking correction of actual shape detection path as described in any one of claims 1 to 9 includes: Executive agency; The laser is rigidly mounted at the end of the actuator; An end effector is rigidly mounted at the end of the actuator. A camera used to acquire 3D point cloud data of the surface of a target object; The path planning module generates walking paths and pose sets. The control system controls the actuator to move its end effector. The data processing module is used for data processing and calculation.

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