A method for verifying laser guidance at the end of a robotic arm

Abstract

The present invention discloses a method for verifying laser guidance at the end of a mechanical arm, comprising the following steps: (1) identifying the position of a tracer on the end of the mechanical arm and the position of a tracer on a detector used to characterize the position of a laser emitted by a laser transmitter through an optical tracking system, and then calculating the position of the laser emitted by the laser transmitter in the coordinate system corresponding to the tracer on the end of the mechanical arm; (2) establishing a laser coordinate system according to the position of the laser emitted by the laser transmitter by the right-hand rule, and calculating the transformation relationship between the laser coordinate system and the coordinate system corresponding to the tracer on the end of the mechanical arm; (3) performing laser guidance verification according to the transformation relationship between the laser coordinate system and the coordinate system corresponding to the tracer on the end of the mechanical arm in step (2). The present invention can verify laser guidance.

Description

Technical Field

[0001] The present invention relates to the field of robotics technology, and in particular to a laser guidance verification method at the end of a robotic arm. Background Art

[0002] Lung cancer is one of the most dangerous cancers to human life and health, and lung biopsy is the gold standard for diagnosing lung tumors. Lung biopsy surgery requires doctors with rich clinical experience to remove lesions for pathological analysis. During lung biopsy surgery, a surgical navigation system is used to guide the operation. The main principle of the surgical navigation system is to align the preoperative CT image coordinate system with the intraoperative spatial coordinate system, so as to realize the real-time display of surgical instruments in the preoperative CT image coordinate space.

[0003] Lung puncture biopsy is an invasive examination, which causes some pain to the patient. Therefore, local anesthesia is needed to relieve the patient's pain. The closer the anesthesia is to the lesion, the better the anesthesia effect. In order to improve the accuracy of the doctor's anesthesia, it is necessary to install a laser light on the navigation device to indicate the position and direction of the lesion on the human body surface. In order for the laser to accurately guide the lesion, it is necessary to calculate the precise relationship between the laser coordinate system and the terminal tracer coordinate system. However, due to processing and installation errors, we need to further verify the laser coordinate system and the terminal tracer coordinate system, so as to verify the laser guidance. Summary of the invention

[0004] Purpose of the invention: In view of the above-mentioned deficiencies, the present invention proposes a method for verifying the laser guidance at the end of a robot arm, which can obtain the transformation relationship between the laser coordinate system and the end tracer coordinate system, and then verify the laser guidance.

[0005] Technical solution:

[0006] A method for verifying laser guidance at the end of a robotic arm, comprising the steps of:

[0007] (1) Identifying the position of the tracer on the end of the robot arm and the position of the tracer on the detector used to characterize the position of the laser emitted by the laser transmitter through the optical tracking system, and then calculating the position of the laser emitted by the laser transmitter in the coordinate system corresponding to the tracer on the end of the robot arm;

[0008] (2) A laser coordinate system is established according to the laser pose emitted by the laser transmitter by using the right-hand rule, and the transformation relationship between the laser coordinate system and the corresponding coordinate system of the tracer at the end of the robotic arm is calculated accordingly;

[0009] (3) Perform laser guidance verification based on the transformation relationship between the laser coordinate system in step (2) and the corresponding coordinate system of the tracer on the end of the robot arm.

[0010] In the step (1), the detector guides the position of the laser point through its tip to characterize the laser posture emitted by the laser transmitter.

[0011] In the step (1), the laser emitter is kept stationary and the coordinates of different laser point positions in the coordinate system corresponding to the tracer at the end of the robotic arm are obtained through different planes. The straight line formed by different laser points is the laser emitted by the laser emitter, and its position and posture are obtained. The straight line formed by different laser points is a straight line obtained by fitting each laser point using the weighted least squares method.

[0012] The establishment of the laser coordinate system specifically includes:

[0013] 1) The straight line formed by different laser points is used as the z-axis of the laser coordinate system;

[0014] 2) Select a point on the z-axis as the origin, and establish a laser coordinate system aligned with the end coordinate system established on the end of the robotic arm according to the right-hand rule; wherein the end coordinate system uses the axis of the navigation channel on the end of the robotic arm as the z-axis, and the laser coordinate system is aligned with the end coordinate system so that the angle between the x-axis or y-axis is the smallest.

[0015] After obtaining the z-axis of the laser coordinate system, determine whether the inner product of the z-axis vector of the robot end coordinate system and the z-axis vector of the laser coordinate system in step 1) is less than 0; if it is less than, the z-axis of the laser coordinate system is reversed; if it is not less than, it remains unchanged, thereby determining the positive direction of the z-axis of the laser coordinate system.

[0016] The specific steps of establishing the laser coordinate system are as follows: selecting a point on the z-axis as the origin, and selecting a straight line direction which is perpendicular to the z-axis of the laser coordinate system and has the smallest angle with the y-axis or x-axis of the robot end coordinate system according to the right-hand rule as the coordinate axis corresponding to the laser coordinate system, and determining the other coordinate axis of the laser coordinate system by the right-hand rule to obtain the laser coordinate system.

[0017] The direction of a straight line perpendicular to the z-axis of the laser coordinate system and with the smallest angle with the y-axis or x-axis of the robot end coordinate system is selected as the coordinate axis corresponding to the laser coordinate system:

[0018] A straight line perpendicular to the z-axis of the laser coordinate system is randomly selected as a candidate y-axis or x-axis, and it is rotated 360 degrees around the z-axis of the laser coordinate system with a step size of 1 degree. After each rotation, the inner product between the vector of the current candidate y-axis or x-axis and the vector of the corresponding coordinate axis of the robot end coordinate system is calculated. If the inner product is less than 0, it is eliminated; if the inner product is greater than 0, the cosine of the angle between the two vectors is calculated;

[0019] The candidate y-axis or x-axis corresponding to the maximum cosine value of the angle is the y-axis or x-axis of the final laser coordinate system.

[0020] There are multiple groups of tracers on the end of the robotic arm. The position and posture of each tracer are identified by an optical tracking system, and the transformation relationship between the coordinate system corresponding to one group of tracers and the laser coordinate system is calculated based on the transformation relationship between the coordinate system corresponding to one group of tracers and the laser coordinate system.

[0021] According to the transformation relationship between the laser coordinate system in step (2) and the corresponding coordinate system of the tracer on the end of the robotic arm, the movement of the robotic arm is controlled so that the laser posture emitted by the laser transmitter changes, and the laser guidance is verified according to whether the deviation between the actual posture of the laser and the target posture is within the set range.

[0022] Beneficial effects: The present invention can establish an accurate relationship between the laser coordinate system and the end tracer, and can obtain the transformation relationship between the laser coordinate system and the end tracer coordinate system, thereby verifying the laser guidance. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a schematic diagram of the laser guidance verification of the end of the robot arm of the present invention;

[0024] Figure 2 To verify the structural diagram of the tooling;

[0025] Figure 3 The figure is a flow chart of the laser guidance verification method of the end of the robot arm of the present invention.

[0026] Among them, 1. the end of the robotic arm, 11. light emitting diode, 12. laser light;

[0027] 2. Probe, 21. Tracer ball, 22. Sharp point;

[0028] 3. Optical tracking system;

[0029] 4. Verification tooling, 41. Tooling tracer ball, 42. Verification channel, 43. Verification channel plane circle. DETAILED DESCRIPTION

[0030] The present invention is further explained below in conjunction with the accompanying drawings and specific embodiments.

[0031] The laser guidance verification architecture of the end of the robot arm of the present invention is as follows Figure 1 As shown, it includes a laser lamp 12 installed on the end 1 of the robot arm, a probe 2 for pointing to the laser point emitted by the laser lamp 12, an optical tracking system 3 for identifying the position of the tracer installed on the end 1 of the robot arm and on the probe 2, and a verification tool 4 for laser guidance verification, as well as a host computer that calculates the target position of the laser emitted by the laser lamp 12 according to the verification channel in the three-dimensional image and the channel on the verification tool and controls the movement of the robot arm accordingly.

[0032] The end of the robot arm Figure 1 As shown, several groups of terminal tracers are installed on the end 1 of the robot arm. In the prior art, the tracer usually includes a reflective ball to improve the visual navigation accuracy. However, the reflective ball has the disadvantages of being large in size, taking up space, and being very easy to be damaged during disinfection and use. Therefore, the tracer balls in each group of terminal tracers of the present invention use light-emitting diodes 11, and each group of terminal tracers includes at least three coplanar and non-colinear light-emitting diodes 11, and the planes where the groups of terminal tracers are located are not coplanar. Specifically, in a specific embodiment of the present invention, there are three groups of terminal tracers, each group includes four light-emitting diodes 11, which are respectively located on the two side surfaces and the upper top inclined surface of the end of the robot arm, as shown in FIG. Figure 1 As shown; specifically, the light emitting diodes 11 corresponding to the three groups of end tracers A, B, and S are defined as A1, A2, A3, A4, B1, B2, B3, B4, S1, S2, S3, and S4 (not shown in the figure); wherein A1, A2, A3, and A4 are installed in the same plane to form a rigid body, which is recorded as the end tracer A, and the corresponding end tracer coordinate system C is established. A , B1, B2, B3, and B4 are installed in the same plane to form a rigid body, which is recorded as the end tracer B. The corresponding end tracer coordinate system C is established. B , S1, S2, S3, and S4 are installed in the same plane to form a rigid body, which is denoted as the end tracer S, and the corresponding end tracer coordinate system C is established. S .

[0033] The laser lamp 12 is installed on the lower end surface of the end 1 of the robot arm, and is used to emit laser for guidance. A probe tracer for tracing the position of the probe 2 is fixedly installed on the probe 2. The probe tracer uses at least three coplanar and non-colinear tracer balls 21. Specifically, there are four tracer balls 21, all fixed on the probe 2; the end of the probe 2 is its sharp point 22, and the laser light emitted by the laser lamp 12 is pointed to the laser point on the corresponding plane through its sharp point 22. The relative position of the sharp point 22 relative to the probe tracer is fixed, and the optical tracking system 3 identifies the position of the probe tracer to obtain the position of the laser point. The optical tracking system 3 is used to obtain and identify the position of the end tracer on the end 1 of the robot arm and the probe tracer on the probe 2 in real time, and send it to the host computer. A tooling tracer 41, a plurality of verification channels 42 and a plurality of verification channel plane circles 43 are installed on the verification tooling 4. The tooling tracer 41 can adopt the tracer on the probe 2; the tooling tracer 41 is asymmetrically installed on the verification tooling 4 for the registration between the three-dimensional image and the optical tracking system; the verification channel 42 is arranged on different planes of the verification tooling 4, and the upper surface of the verification channel 42 has a plane circle 43 of the verification channel, which is used to verify whether the intersection of the laser point and the tooling surface is within the plane circle. If it is within the plane circle, it means that the laser point is within the accuracy range and meets the laser accuracy requirements.

[0034] The host computer obtains the z-axis of the laser coordinate system C2 by collecting different laser points on different planes, constructs the selected laser coordinate system according to the right-hand rule, and aligns the laser coordinate system C2 with the robot end coordinate system C1 and updates the laser coordinate system to obtain the final laser coordinate system C2, and calculates the transformation relationship between the coordinate system corresponding to the end tracer on the end of the robot and the final laser coordinate system C2. In the laser guidance stage, the laser is controlled by the movement of the robot arm to shoot laser points at appropriate positions on the patient's body surface to guide the doctor's operation. In the execution stage, the navigation channel and the planning channel are overlapped by controlling the movement of the robot arm. Therefore, aligning the laser coordinate system C2 with the robot end coordinate system C1 can make the inverse solution selection strategy of the robot arm movement corresponding to the laser guidance stage and the execution stage consistent, so that the two stages use a common robot arm movement inverse solution selection strategy, reducing the difficulty of development;

[0035] Among them, the transformation relationship between the coordinate system corresponding to the end tracer on the end of the robot arm and the final laser coordinate system C2 is calculated while keeping the position of the robot arm unchanged so that the position of the laser light on it does not move. Based on this, the laser coordinate system is established according to the above, and the transformation relationship between the coordinate system corresponding to the end tracer and the laser coordinate system is obtained. The upper computer aligns the tracer on the three-dimensional image obtained by scanning the verification tool to obtain the transformation relationship between the three-dimensional image and the optical tracking system, and selects a verification channel in the three-dimensional image as the target posture that the laser needs to guide. Then, according to the transformation relationship between the three-dimensional image and the optical tracking system and the transformation relationship between the coordinate system corresponding to a certain end tracer on the end of the robot arm and the laser coordinate system, the movement of the robot arm is controlled so that the laser emitted by the laser light on it reaches the target posture obtained above, and it is judged whether the laser emitted by the laser light can hit the corresponding verification channel plane circle on the verification tool, so as to verify the accuracy of the laser guidance.

[0036] The laser guidance verification method of the end of the robot arm of the present invention is as follows Figure 3 As shown, the following steps are included:

[0037] (1) Adjust the robotic arm so that a group of end tracers on it is facing the optical tracking system, and the laser lamp on the end of the robotic arm emits laser to a plane to obtain a corresponding laser point, and the tip of the probe points to the laser point so that the coordinates of the probe tip and the laser point are the same;

[0038] (2) The end tracer and the probe tracer are identified by the optical tracking system, and the transformation relationship between the coordinate system corresponding to the probe tracer and the end tracer and the coordinate system of the optical tracking system is obtained, which are recorded as T0 and T1 respectively; at the same time, the coordinate p of the tip in the optical tracking system is calculated according to the probe design parameters. t , and then calculate the coordinates p of the laser point in the coordinate system corresponding to the end tracerj =T1 -1 *T0*p t ;

[0039] In a specific embodiment of the present invention, the end tracer B (i.e., the end tracer at the upper top slope of the end of the robot arm) is selected to face the optical tracking system;

[0040] (3) Construct laser coordinate system C2;

[0041] In order to provide accurate laser guidance, it is necessary to establish a corresponding laser coordinate system based on the laser point emitted by the laser lamp and calculate the transformation relationship between the laser coordinate system and the corresponding coordinate system of the end tracer in step (1), as follows:

[0042] (31) On the basis of step (1), the laser lamp is kept in a fixed position and different laser points are obtained through different planes, and the coordinates of each laser point in the coordinate system corresponding to the end tracer are calculated according to step (2), and each laser point is fitted with a weighted least square method to obtain a straight line, and the straight line is used as the z-axis of the laser coordinate system;

[0043] In this step, in order to ensure that the inverse solution selection strategies of the robot arm motion corresponding to the guidance stage and the execution stage are consistent, the smaller the angle between the corresponding coordinate axes of the laser coordinate system and the robot arm end coordinate system, the lower the difficulty of algorithm development, that is, the laser coordinate system and the robot arm end coordinate system need to be aligned, so it is also necessary to determine the positive direction of the z-axis of the laser coordinate system. Specifically, according to the actual operation process, it is necessary to ensure that the angle between the z-axis of the navigation channel on the robot arm end and the laser coordinate system is an acute angle. According to the aforementioned method, the robot arm end coordinate system is established in the navigation channel on the robot arm end, and its z-axis is the axis of the navigation channel. Then the z-axis vector of the laser coordinate system (that is, the fitted straight line) is Z1, and the z-axis vector of the robot arm end coordinate system is Z2. It is determined whether the inner product of the two vectors is less than 0. If it is, the z-axis of the laser coordinate system is reversed. If it is not, it remains unchanged, so that the positive direction of the z-axis of the laser coordinate system can be determined;

[0044] Among them, the robot arm end coordinate system C1 is a coordinate system established according to the right-hand rule, with the axis of the navigation channel on the robot arm end as the z-axis; more specifically, the various axes of the robot arm end coordinate system C1 can be obtained through three-coordinate measurement, wherein the axis of the navigation channel on the robot arm end is taken as the z-axis, the straight line perpendicular to the two side surfaces of the robot arm end is taken as the x-axis, the straight line perpendicular to the plane where the z-axis and x-axis of the robot arm end are located is taken as the y-axis, and the intersection of the upper surface of the navigation channel and the axis of the navigation channel is taken as the origin, and the robot arm end coordinate system C1 is established according to the right-hand rule.

[0045] (32) Select a point on the z-axis of the laser coordinate system as the origin, and establish a laser coordinate system aligned with the end coordinate system of the robot arm according to the right-hand rule, so as to obtain a transformation relationship T1′ between the coordinate system corresponding to the end tracer of step (1) and the laser coordinate system;

[0046] In one embodiment of the present invention, a laser coordinate system aligned with the robot arm end coordinate system can be established in the following manner: a point on the z-axis of the laser coordinate system is selected as the origin, and the x-axis and y-axis are determined according to the right-hand rule to establish a candidate laser coordinate system. The candidate laser coordinate system is then rotated around its z-axis and the angle between its x-axis or y-axis and the corresponding coordinate axis of the robot arm end coordinate system is minimized, thereby obtaining the final laser coordinate system.

[0047] In another embodiment of the present invention, the laser coordinate system aligned with the robot end coordinate system can also be established by selecting a point on the z-axis of the laser coordinate system as the origin, selecting a straight line perpendicular to the z-axis of the laser coordinate system and having the smallest angle with the y-axis of the robot end coordinate system according to the right-hand rule as the y-axis of the laser coordinate system, and determining the x-axis of the laser coordinate system by the right-hand rule, thereby obtaining the laser coordinate system;

[0048] The direction of a straight line perpendicular to the z-axis of the laser coordinate system and with the smallest angle with the y-axis of the coordinate system of the end of the robot arm is selected as the y-axis of the laser coordinate system. Specifically, a straight line perpendicular to the z-axis of the laser coordinate system is randomly selected as the candidate y-axis, and it is rotated 360 degrees around the z-axis of the laser coordinate system with a step size of 1 degree. After each rotation, the inner product between the vector where the current candidate y-axis is located and the vector where the y-axis of the coordinate system of the end of the robot arm is located is calculated. If the inner product is less than 0, it means that the current candidate y-axis and the y-axis of the coordinate system of the end of the robot arm form an obtuse angle, and it is eliminated; if the inner product is greater than 0, the cosine of the angle between the two vectors is calculated; the candidate y-axis corresponding to the time when the cosine of the angle is the largest, that is, the angle between the two vectors is the smallest, is the y-axis of the final laser coordinate system.

[0049] In addition to the above-mentioned embodiment of obtaining the laser coordinate system, in other embodiments of the present invention, after determining the z-axis of the laser coordinate system, a straight line perpendicular to the z-axis of the laser coordinate system is first selected as the x-axis of the candidate laser coordinate system, and the laser coordinate system is aligned with the coordinate system of the end of the robot arm to determine the x-axis of the final laser coordinate system (the alignment calculation method refers to the above-mentioned y-axis rotation calculation process around the z-axis of the laser coordinate system), and the y-axis of the laser coordinate system is determined by the obtained z-axis of the laser coordinate system and the x-axis of the final laser coordinate system, and finally the final laser coordinate system is obtained.

[0050] In the present invention, after the x-axis and y-axis of the laser coordinate system are obtained, vector normalization is performed on the coordinate axes respectively.

[0051] (4) Calculate the transformation relationship between the coordinate system corresponding to other end tracers and the laser coordinate system;

[0052] There are other groups of end tracers at the end of the robot arm, so it is also necessary to determine the transformation relationship between the coordinate system corresponding to the other groups of end tracers and the laser coordinate system;

[0053] The positions of the other groups of end tracers are identified by the optical tracking system, and the transformation relationship T between the coordinate system corresponding to one group of end tracers (defined as group K) and the coordinate system of the optical tracking system is obtained. K , and combined with the transformation relationship T1′ between the coordinate system corresponding to the end tracer in step (3) and the laser coordinate system, and the transformation relationship T1 between the coordinate system of the optical tracking system and the corresponding coordinate system of the end tracer obtained in the above step (2), the transformation relationship T between the coordinate system corresponding to the K groups of end tracers and the laser coordinate system can be obtained. K ′=T K -1 *T1*T1′;

[0054] (5) Laser calibration verification;

[0055] Use Figure 2 A verification tooling is used for laser guidance verification. A tooling tracer, several verification channels and several verification channel plane circles are installed on the verification tooling. A CT scan is performed on the verification tooling to obtain its three-dimensional image. The transformation relationship between the three-dimensional image and the optical tracking system is obtained by identifying the tracer on the verification tooling in the three-dimensional image and combining the tooling tracer posture obtained by the optical tracking system and the verification tooling design parameters. A verification channel in the three-dimensional image is selected as the target posture that needs to be guided by the laser. The optical tracking system identifies one group of end tracers on the end of the robot arm, and then the movement of the robot arm is controlled according to the transformation relationship between the three-dimensional image and the optical tracking system and the transformation relationship between the coordinate system corresponding to the group of end tracers and the laser coordinate system, so that the laser emitted by the laser lamp thereon moves to its target posture. At this time, it is judged whether the laser emitted by the laser lamp can hit the corresponding verification channel on the verification tooling, so as to verify the accuracy of the laser guidance.

[0056] The present invention guides the laser point emitted by the laser lamp through a probe, and constructs a laser coordinate system according to the laser point position on different planes to obtain the laser point posture, so as to establish an accurate relationship between the laser coordinate system and the end tracer, thereby verifying the laser guidance.

[0057] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, various equivalent transformations (such as quantity, shape, position, etc.) can be made to the technical scheme of the present invention, and these equivalent transformations all belong to the protection scope of the present invention.

Claims

1. A method for verifying laser guidance at the end of a robotic arm, characterized in that: Includes steps: (1) Identify the position and posture of a group of tracers on the end of the robot arm and the position and posture of the tracers on the detector used to characterize the position and posture of the laser emitted by the laser transmitter through the optical tracking system, and then calculate the position and posture of the laser emitted by the laser transmitter in the corresponding coordinate system of the group of tracers on the end of the robot arm; (2) The laser coordinate system is established according to the laser pose emitted by the laser transmitter using the right-hand rule, as follows: 1) Use the straight line formed by different laser points as the z-axis of the laser coordinate system; 2) Select a point on the z-axis as the origin, and establish a laser coordinate system aligned with the end coordinate system established on the end of the robotic arm according to the right-hand rule; wherein the end coordinate system uses the axis of the navigation channel on the end of the robotic arm as the z-axis, and the laser coordinate system is aligned with the end coordinate system so that the angle between the x-axis or y-axis of the two is the smallest; Based on this calculation, the transformation relationship between the laser coordinate system and the corresponding coordinate system of the group of tracers at the end of the robotic arm is obtained; (3) Perform laser guidance verification based on the transformation relationship between the laser coordinate system in step (2) and the corresponding coordinate system of the group of tracers at the end of the robotic arm.

2. The method for verifying the laser guidance at the end of a robotic arm according to claim 1, characterized in that: In the step (1), the detector guides the position of the laser point through its tip to characterize the laser posture emitted by the laser transmitter.

3. The method for verifying the laser guidance of the end of a robotic arm according to claim 2, characterized in that: In the step (1), the laser emitter is kept stationary and the coordinates of different laser point positions in the coordinate system corresponding to the tracer at the end of the robotic arm are obtained through different planes. The straight line obtained by fitting using the weighted least squares method is the laser emitted by the laser emitter, and its position and posture are then obtained.

4. The method for verifying the laser guidance at the end of a robotic arm according to claim 1, characterized in that: After obtaining the z-axis of the laser coordinate system, determine whether the inner product of the z-axis vector of the robot end coordinate system and the z-axis vector of the laser coordinate system in step 1) is less than 0; if so, the z-axis of the laser coordinate system is reversed; if not, it remains unchanged, thereby determining the positive direction of the z-axis of the laser coordinate system.

5. The method for verifying the laser guidance at the end of a robotic arm according to claim 4, characterized in that: The specific steps of establishing the laser coordinate system are as follows: selecting a point on the z-axis as the origin, and selecting a straight line direction which is perpendicular to the z-axis of the laser coordinate system and has the smallest angle with the y-axis or x-axis of the robot end coordinate system according to the right-hand rule as the coordinate axis corresponding to the laser coordinate system, and determining the other coordinate axis of the laser coordinate system by the right-hand rule to obtain the laser coordinate system.

6. The method for verifying the laser guidance at the end of a robotic arm according to claim 4, characterized in that: The direction of a straight line perpendicular to the z-axis of the laser coordinate system and with the smallest angle with the y-axis or x-axis of the robot end coordinate system is selected as the coordinate axis corresponding to the laser coordinate system: A straight line perpendicular to the z-axis of the laser coordinate system is randomly selected as a candidate y-axis or x-axis, and it is rotated 360 degrees around the z-axis of the laser coordinate system with a step size of 1 degree. After each rotation, the inner product between the vector of the current candidate y-axis or x-axis and the vector of the corresponding coordinate axis of the robot end coordinate system is calculated. If the inner product is less than 0, it is eliminated; if the inner product is greater than 0, the cosine of the angle between the two vectors is calculated; The candidate y-axis or x-axis corresponding to the maximum cosine value of the angle is obtained as the y-axis or x-axis of the final laser coordinate system.

7. The method for verifying the laser guidance of the end of a robotic arm according to claim 1, characterized in that: There are multiple groups of tracers on the end of the robotic arm. The position and posture of each tracer is identified by the optical tracking system, thereby obtaining the transformation relationship between the coordinate system of the optical tracking system and the coordinate system corresponding to each tracer. Therefore, based on the calculated transformation relationship between the coordinate system corresponding to one group of tracers and the laser coordinate system, combined with the transformation relationship between the coordinate system of the optical tracking system and the coordinate system corresponding to the group of end tracers, the transformation relationship between the coordinate system corresponding to other groups of tracers and the laser coordinate system is calculated.

8. The method for verifying the laser guidance at the end of a robotic arm according to any one of claims 1 to 7, characterized in that: According to the transformation relationship between the laser coordinate system in step (2) and the coordinate system corresponding to the tracer on the end of the robotic arm, the movement of the robotic arm is controlled so that the laser posture emitted by the laser transmitter changes. The laser guidance is verified based on whether the deviation between the actual posture of the laser and the target posture is within the set range.

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