CN-121999052-A - Point cloud data acquisition and accurate docking method and device

CN121999052ACN 121999052 ACN121999052 ACN 121999052ACN-121999052-A

Abstract

The invention discloses a point cloud data acquisition and accurate docking method and device, wherein the point cloud data acquisition method comprises the following steps of: the method comprises the steps of respectively obtaining a first compression amount of a first time probe, a coordinate of a second time mechanical arm in a base coordinate system, a second compression amount of a third time probe and a coordinate of the mechanical arm in the base coordinate system, calculating a compression change amount of the probe according to the first compression amount and the second compression amount, calculating a direction vector of movement of the mechanical arm according to the coordinate of the second time mechanical arm and the coordinate of the third time mechanical arm, calculating displacement components corresponding to all coordinate axes of the compression change amount of the probe according to the compression change amount of the probe and the direction vector of movement of the mechanical arm, and calculating coordinates of point clouds corresponding to a probe tip when the probe is just contacted with an object to be butted and the compression amount of the probe is the first compression amount according to the coordinate of the third time mechanical arm and the displacement components corresponding to all coordinate axes. By adopting the method, the accuracy of the point cloud data acquisition can be greatly improved.

Inventors

MOU PING
XIE YUJIE
LU JIANLIN
WANG SHOUYAN
CHEN DONG

Assignees

重庆朗维机电技术有限公司

Dates

Publication Date: 20260508
Application Date: 20260410

Claims (10)

1. The point cloud data acquisition method is characterized by comprising the following steps of: The method comprises the steps of respectively obtaining a first compression amount of a first moment probe, a coordinate of a second moment mechanical arm in a base coordinate system, a second compression amount of a third moment probe and a coordinate of the mechanical arm in the base coordinate system, wherein the probe is fixed on an actuator at the tail end of the mechanical arm and can move relative to the actuator along a self axis, the axis of the probe is parallel to a coordinate axis of a tool coordinate system, the tool coordinate system is a coordinate system corresponding to the actuator, the first moment is a moment when the probe is not contacted with a piece to be docked, the second moment and the third moment are when the probe is contacted with the piece to be docked, contact positions of the two moment probes and the piece to be docked are the same, the probe is compressed, the movement direction of the actuator between the second moment and the third moment is along the axial direction of the probe, and the compression amount of the second moment probe is unequal to the compression amount of the third moment probe; Calculating to obtain the compression variation of the probe according to the first compression and the second compression; calculating according to the coordinates of the mechanical arm at the second moment and the coordinates of the mechanical arm at the third moment to obtain a direction vector of the movement of the mechanical arm; calculating displacement components corresponding to the compression variation of the probe in each coordinate axis according to the compression variation of the probe and the direction vector of the movement of the mechanical arm; and calculating according to the coordinates of the mechanical arm at the third moment and displacement components corresponding to the coordinate axes to obtain the coordinates of the point cloud corresponding to the probe tip in the base coordinate system when the probe is just contacted with the piece to be butted and the compression amount of the probe is the first compression amount.
2. The method for collecting point cloud data according to claim 1, wherein the direction vector of the movement of the mechanical arm calculated according to the coordinates of the mechanical arm at the second moment and the coordinates of the mechanical arm at the third moment is: The second moment and the third moment are the corresponding different moments in the probe compression process, and the direction vector of the movement of the mechanical arm The method comprises the following steps: =( , , ), Or alternatively The second moment and the third moment are the corresponding different moments in the rebound process of the probe, and the direction vector of the movement of the mechanical arm The method comprises the following steps: =( , , ), Wherein, the The coordinates of the mechanical arm at the third moment, =( ), The X coordinate value of the mechanical arm coordinate at the third moment, The Y coordinate value of the arm coordinate at the third moment, The Z coordinate value of the mechanical arm coordinate at the third moment, The coordinates of the mechanical arm at the second moment, Is the direction vector of the movement of the mechanical arm The component in the X-axis is, Is the direction vector of the movement of the mechanical arm The component on the Y-axis is, Is the direction vector of the movement of the mechanical arm A component in the Z-axis.
3. The method for collecting point cloud data according to claim 2, wherein the displacement components of the compression variation of the probe corresponding to each coordinate axis according to the compression variation of the probe and the direction vector of the movement of the mechanical arm are as follows: calculating displacement component of compression variation of probe on X-axis of basic coordinate system , wherein, = , In the formula, The compression variation of the probe; calculating displacement component of compression variation of probe on Y-axis of basic coordinate system , wherein, = ; Calculating displacement component of compression variation of probe on Z axis of basic coordinate system , wherein, = ; And calculating according to the coordinates of the mechanical arm at the third moment and displacement components corresponding to the coordinate axes, and when the probe is just contacted with the piece to be butted and the compression amount of the probe is the first compression amount, the coordinates of point clouds corresponding to the probe tip in a base coordinate system are as follows: Pt=( ) ( , , ), in the formula, pt is the coordinate of the contact point position on the piece to be butted when the probe is contacted with the piece to be butted at the second moment.
4. The accurate butt joint method is characterized by comprising the following steps of: Acquiring a first point cloud set on a workpiece to be butted, wherein the workpiece to be butted comprises a first workpiece to be butted and a second workpiece to be butted, the first point cloud set comprises a first workpiece to be butted point cloud set and a second workpiece to be butted point cloud set, the first workpiece to be butted point cloud set comprises a first workpiece to be butted surface and point cloud on a side wall, and the second workpiece to be butted point cloud set comprises a second workpiece to be butted surface and point cloud on the side wall; Determining normal vectors and axis coordinates of a butt joint surface of a first workpiece to be butted and a second workpiece to be butted according to the first point cloud set; calculating according to the normal vector and the axis coordinates of the abutting surfaces of the first workpiece to be abutted and the second workpiece to be abutted to obtain pose adjusting parameters for enabling the first workpiece to be abutted and the second workpiece to be abutted; And controlling the first workpiece to be butted according to the pose adjustment parameters so as to finish the butting of the first workpiece to be butted and the second workpiece to be butted.
5. The method of claim 4, wherein the acquiring the first point cloud on the workpiece to be docked by using the method of any one of claims 1 to 3 further comprises: The method comprises the steps of controlling a six-degree-of-freedom motion platform to translate or rotate in a neutral point according to a positive direction and a negative direction of X, Y, Z axes respectively by a preset amount, wherein a target is arranged on the motion platform, and measuring a target coordinate measured by the platform after the translation or rotation of each time by the preset amount; Calculating to obtain a first rotation matrix and a position coordinate of a coordinate system origin of the motion platform in a measurement platform coordinate system according to target coordinates after each translation and rotation of the motion platform by a preset amount ; Position coordinates in a measuring platform coordinate system according to the coordinate system origin of the moving platform And the first rotation matrix R is calculated to obtain a transformation relation between a measuring platform coordinate system and a moving platform coordinate system: P OR =R , in the formula, Is a motion platform coordinate system Is a dot in (2); R is a first rotation matrix; for measuring the platform coordinate system Points in (a), and Corresponding to each other.
6. The method of claim 4, wherein calculating the pose adjustment parameters for the first workpiece to be docked and the second workpiece to be docked according to the normal vector and the axis coordinates of the docking surfaces of the first workpiece to be docked and the second workpiece to be docked, comprises: Calculating normal vector of abutting surface of first to-be-abutted element in quaternion mode Normal vector rotated to the abutting surface of the second piece to be abutted Is a second rotation matrix of (2) ; According to the second rotation matrix Calculating rotation pose data of the first butt joint surface after rotation change =( , ); According to the butt joint surface pose data of the second workpiece to be butt-jointed Rotation position and posture data of first butt joint surface =( , ) Determining a first translation vector of a first part to be abutted , wherein, = ; According to the first translation vector And a second rotation matrix Determining pose adjustment parameters or according to the first translation vector Compensation of the first translation vector And a second rotation matrix And determining pose adjustment parameters.
7. The precise docking method of claim 6, wherein the first translation vector is compensated by The method is determined by the following steps: Extracting a conversion Euler angle of a coordinate system of the moving platform according to the first rotation matrix R ; According to the second butt joint surface pose data Position coordinates in the coordinate system of the measuring platform with the origin of the coordinate system of the moving platform Calculating to obtain mass center translation vector of motion platform ; Transforming the coordinate system of the motion platform according to Euler angles Transformed to be parallel to the coordinate system of the measuring platform and translated according to the mass center Exchanging centroid corresponding positions; From a second rotation matrix Extracting the rotary Euler angle Determining a coordinate Pt Rd of a docking preparation position according to the axis coordinate of the docking surface of the second workpiece to be docked, the preset distance and the direction from the axis of the docking surface of the second workpiece to be docked to the docking surface of the first workpiece to be docked; Determining a second translation vector t rd of the first part to be docked according to the coordinate Pt Rd of the docking ready position and the axis coordinate of the first part to be docked; the motion platform is controlled to drive the first to-be-abutted part to rotate according to the Euler angle Rotating and translating to a docking ready position according to a second translation vector t rd ; Measuring the center coordinates of the abutting surface of the first workpiece to be abutted And the center coordinate of the butt joint surface of the second workpiece to be butted According to 、 Calculating to obtain the compensation quantity of the first translation vector 。
8. The method of claim 6, wherein the determining the normal vector and the axis coordinates of the abutting surfaces of the first workpiece to be abutted and the second workpiece to be abutted according to the first point cloud set further comprises obtaining a second point cloud set, wherein the second point cloud set comprises a first pin hole point cloud set formed by the point cloud of the pin hole of the first workpiece to be abutted and a second pin hole point cloud set formed by the point cloud of the pin hole of the second workpiece to be abutted; Determining first pin position data of pin holes on a first workpiece to be butted according to the second point cloud set And second pin position and orientation data of pin holes on a second workpiece to be butted ; The position and posture adjustment parameters for enabling the first workpiece to be docked and the second workpiece to be docked to be completed are obtained through calculation according to the normal vector and the axis coordinates of the docking surfaces of the first workpiece to be docked and the second workpiece to be docked, and the position and posture adjustment parameters further comprise: according to the butt joint surface pose data of the first workpiece to be butted Docking surface pose data of second to-be-docked piece First pin position and orientation data And second pinning site pose data Determining pin hole rotation matrix , According to pin hole rotation matrix A second rotation matrix And a first translation vector Determining pose adjustment parameters or rotating matrix according to pin holes Pin hole alignment compensation value A second rotation matrix First translation vector And the compensation amount of the first translation vector And determining pose adjustment parameters.
9. The precise butt joint method according to claim 8, wherein the pin hole alignment compensation value And the compensation amount of the first translation vector The method is determined by the following steps: Extracting a conversion Euler angle of a coordinate system of the moving platform according to the first rotation matrix R Then according to the second butt joint surface pose data Position coordinates in the coordinate system of the measuring platform with the origin of the coordinate system of the moving platform Calculating to obtain mass center translation vector of motion platform ; First coordinate system of motion platform According to the transformation Euler angle Transformed to and from a second coordinate system Parallel and according to the mass-center translation vector Exchanging centroid corresponding positions; From the slave Extracting the rotary Euler angle Determining a coordinate Pt Rd of a docking preparation position according to the axis coordinate of the docking surface of the second workpiece to be docked, the preset distance and the direction from the axis of the docking surface of the second workpiece to be docked to the docking surface of the first workpiece to be docked; Determining a second translation vector t rd of the first part to be docked according to the coordinate Pt Rd of the docking ready position and the axis coordinate of the first part to be docked; the motion platform is controlled to drive the first to-be-abutted part to rotate according to the Euler angle Rotating and translating to a docking ready position according to a second translation vector t rd ; measuring the first joint to be abutted at the moment coordinates of pin hole center on piece Coordinates of center of pin hole on second piece to be abutted Center coordinates of a butt joint surface of a first to-be-butted part And the center coordinate of the butt joint surface of the second to-be-butted part ; According to the first to-be-abutted part center coordinates of the butt joint surface And the center coordinate of the butt joint surface of the second to-be-butted part Calculating to obtain the compensation quantity of the first translation vector ; According to the first to-be-abutted part center coordinates of the butt joint surface Coordinates of center of pin hole on first to-be-butted piece Calculating to obtain a fifth vector of the center of the first part to be butted pointing to the center of the pin hole on the first part to be butted According to the central coordinate of the butt joint surface of the second workpiece to be butt-jointed Coordinates of center of pin hole on second piece to be abutted Calculating to obtain a sixth vector of the center of the second piece to be butted pointing to the center of the pin hole on the second piece to be butted ; According to the fifth vector Sixth vector Calculating the angle difference between the pin hole on the first part to be butted and the pin hole on the second part to be butted ; According to the angle difference And determining a pin hole alignment compensation value according to the right hand rule according to the actual rotation direction of the first to-be-butted piece 。
10. The device comprises a memory and a controller which are sequentially in communication connection, wherein the memory is stored with a computer program, and the device is characterized in that the controller is used for reading the computer program, executing a point cloud data acquisition method according to any one of claims 1-3 or executing a precise docking method according to any one of claims 4-9.

Description

Point cloud data acquisition and accurate docking method and device Technical Field The invention belongs to the technical field of point cloud data acquisition, and particularly relates to a point cloud data acquisition and accurate butt joint method and device. Background The quality of the large dock has a direct impact on the overall performance of the dock during docking, such as for large cabins. In the process of docking, the large-scale docking piece generally collects point clouds on the docking piece to determine characteristics such as an axis of the docking piece, for example, "a cabin virtual docking method based on real point cloud data" with the application number of CN 202511673641.8. The accuracy of acquisition of point cloud data on the butt joint part directly relates to the accuracy of characteristic determination such as the axis of the subsequent butt joint part, and further directly influences the accuracy of butt joint. The point cloud data acquisition on the existing butt joint part is realized by adopting a 3D camera or a probe. For example, the application number is CN202211721133.9, namely a 3D point cloud-based mechanical arm and binocular camera hand-eye calibration method is used for realizing point cloud data acquisition by adopting a 3D camera, and for example, the application number is CN201810381890.3, namely a calibration device for real-time tracking of free bone positions is used for realizing point cloud data acquisition by adopting a probe. However, the existing 3D camera is adopted to realize point cloud data acquisition, the accuracy of the point cloud data acquisition is affected by the accuracy of the 3D camera and the point cloud generation method, and the problem of low accuracy exists. The probe is adopted to realize the point cloud data acquisition, and the probe has the following problems: The measuring point position coordinates are determined by adopting the contact between the probe and the measuring point position on the surface of the workpiece, the probe needs to be precisely controlled to improve the acquisition precision, namely, the probe needs to be just contacted with the surface of the workpiece, so that the control precision of the probe is high, and the repeated precision is low. Disclosure of Invention The invention provides a method and a device for acquiring and accurately butting point cloud data, which aim to solve the problem of low accuracy of the existing point cloud data acquisition and effectively improve the accuracy of the point cloud acquisition. The aim of the invention is realized by the following technical scheme: The first aspect of the invention discloses a point cloud data acquisition method, which comprises the following steps: The method comprises the steps of respectively obtaining a first compression amount of a first moment probe, a coordinate of a second moment mechanical arm in a base coordinate system, a second compression amount of a third moment probe and a coordinate of the mechanical arm in the base coordinate system, wherein the probe is fixed on an actuator at the tail end of the mechanical arm and can move relative to the actuator along a self axis, the axis of the probe is parallel to a coordinate axis of a tool coordinate system, the tool coordinate system is a coordinate system corresponding to the actuator, the first moment is a moment when the probe is not contacted with a piece to be docked, the second moment and the third moment are when the probe is contacted with the piece to be docked, contact positions of the two moment probes and the piece to be docked are the same, the probe is compressed, the movement direction of the actuator between the second moment and the third moment is along the axial direction of the probe, and the compression amount of the second moment probe is unequal to the compression amount of the third moment probe; Calculating to obtain the compression variation of the probe according to the first compression and the second compression; calculating according to the coordinates of the mechanical arm at the second moment and the coordinates of the mechanical arm at the third moment to obtain a direction vector of the movement of the mechanical arm; calculating displacement components corresponding to the compression variation of the probe in each coordinate axis according to the compression variation of the probe and the direction vector of the movement of the mechanical arm; and calculating according to the coordinates of the mechanical arm at the third moment and displacement components corresponding to the coordinate axes to obtain the coordinates of the point cloud corresponding to the probe tip in the base coordinate system when the probe is just contacted with the piece to be butted and the compression amount of the probe is the first compression amount. The second aspect of the invention discloses an accurate butt joint method, which comprises the following steps: Acquiring poi