Method and system for registering surgical robot coordinate system and CT machine coordinate system

Abstract

The present invention discloses a method and system for aligning the coordinate system of a surgical robot with the coordinate system of a CT machine. The method includes a 3D structured light camera and a calibration plate used in conjunction with a surgical robot console, a robotic arm, and a CT machine. A 3D vision system is used to align the coordinate system of the CT machine with the coordinate system of the robotic arm in the surgical robot. The 3D structured light camera in the 3D vision system moves synchronously with the robotic arm and the puncture device fixedly installed at the end of the robotic arm. The coordinate alignment process during robotic surgery is greatly simplified, the operation is simple for users, and the learning and training time of medical staff is greatly shortened. In addition, the 3D structured light camera is installed at the end of the robotic arm together with the puncture device, which reduces the size of the surgical robot equipment and greatly reduces the equipment space occupied by CT operating rooms, so that it can be carried out in more hospitals.

Description

Technical Field

[0001] The present invention relates to the field of puncture robots, and in particular to a method and system for aligning a surgical robot coordinate system with a CT machine coordinate system. Background Art

[0002] During a robotic puncture procedure, the doctor uses medical imaging equipment (such as a CT scanner) to diagnose the patient and develop a surgical plan. The surgical robot then performs the puncture according to the doctor's plan. Only after the robot's coordinate system is aligned with the coordinate system of the medical imaging equipment can the robot perform the procedure according to the doctor's plan.

[0003] Currently, most surgical robots use infrared binocular cameras to capture images of landmark components attached to the robotic arm and the human body. Combined with the CT images of the landmark components attached to the body, these cameras use pattern recognition and spatial geometry algorithms to determine the coordinate alignment between the robotic arm and the CT scanner. This technology and method requires the fixed installation of landmark components on both the patient and the robotic arm, as well as the placement of a large infrared binocular camera outside the robotic arm in a suitable field of view. The entire system is complex and inconvenient to operate, requiring extensive training for medical personnel. In particular, the need for the patient's cooperation in securing the landmark components has limited the widespread adoption and application of surgical robots. Summary of the Invention

[0004] The purpose of the present invention is to provide a method for aligning the coordinate system of a surgical robot with the coordinate system of a CT machine. This method is a completely new alignment method. The present invention only requires a high-precision, small-sized 3D structured light camera to be fixedly installed at the end of a robotic arm. In combination with a calibration plate specially designed based on the 3D structured light camera of the present invention, the calibration plate is placed on the CT machine to complete the alignment of the coordinates of the robotic arm with the coordinates of the CT machine. There is no need to fix corresponding markers on the robotic arm and the patient, nor is there a need to separately install a large infrared binocular camera. This simplifies the surgical robot equipment and makes it easier to use and operate. It can be widely promoted and applied and is suitable for medical institutions of all levels.

[0005] The method for aligning the coordinate system of the surgical robot and the coordinate system of the CT machine in the present invention uses a 3D vision system to align the coordinate system of the CT machine with the coordinate system of the robotic arm in the surgical robot. The 3D structured light camera in the 3D vision system moves synchronously with the robotic arm and the puncture device fixedly installed at the end of the robotic arm.

[0006] Preferably, the 3D vision system includes a 3D structured light camera installed at the end of the robotic arm and fixed to the puncture device as a whole, and a calibration plate that can be directly placed on the CT machine and is located within the shooting range of the 3D structured light camera.

[0007] Preferably, the method for registering the coordinate system of the CT machine and the coordinate system of the robotic arm is characterized by performing the following steps:

[0008] 1) Move the robotic arm with the 3D structured light camera to the surgical area next to the CT machine;

[0009] 2) placing the calibration plate on the CT machine within the range that can be captured by the 3D structured light camera;

[0010] 3) starting a registration program, the robotic arm carrying the 3D structured light camera moves sequentially to multiple positions, and after moving to each position, the 3D structured light camera is turned on to project multiple sets of structured light and collect photos of the calibration structure in the calibration plate projected by the structured light. The robotic arm transformation parameters of each position and the photos of the calibration structure in the calibration plate are recorded by computer software, and a hand-eye calibration algorithm is used to obtain the transformation relationship between the calibration plate coordinate system and the robotic arm coordinate system, which is a third transformation matrix;

[0011] 4) The robotic arm is retracted to its initial position, the calibration plate remains on the CT machine and is started to scan the calibration plate; CT image data of the four spherical calibration elements on the calibration plate are acquired, and a coordinate matrix of the calibration plate with respect to the centers of the four spherical calibration elements is combined to obtain a transformation relationship between the CT coordinate system and the calibration plate coordinate system, which is a fourth transformation matrix;

[0012] 5) Based on the third transformation matrix between the calibration plate coordinate system and the robotic arm coordinate system and the fourth transformation matrix between the CT machine coordinate system and the calibration plate coordinate system, the transformation relationship between the CT machine coordinate system and the robotic arm coordinate system is obtained as the fifth transformation matrix, and the coordinate alignment of the CT machine coordinate system and the robotic arm coordinate system is completed.

[0013] Preferably, in step 3), the following steps are performed:

[0014] 3.1) Start the registration program, the robot arm carrying the 3D structured light camera moves to n pre-set different postures in sequence, and after moving to each posture, obtains the transformation relationship between the calibration plate coordinate system and the camera coordinate system at each posture, which is the first transformation matrix W BC The transformation relationship between the center point of the end of the manipulator and the manipulator coordinate system is the second transformation matrix W AT ;

[0015] 3.2) Select the first transformation matrix W corresponding to two of the poses (i, j) BC and the second transformation matrix W AT , according to the following equation (1), the transformation matrix W between the camera coordinate system and the center point coordinate system of the robot end is obtained: CT (ij) ;

[0016] W AT (i) W CT (ij) W BC (i) =W AT (j) W CT (ij) W BC (j) (1)

[0017] 3.3) Obtain the transformation matrix W between the calibration plate coordinate system and the manipulator coordinate system for the two poses (i, j) according to the following equation (2): AB (ij) ;

[0018] W AB (ij) =W AT (i) W CT (ij) W BC (i) =W AT (j) W CT (ij) W BC (j) (2)

[0019] 3.4) Repeat steps 3.2) and 3.3) to select the first transformation matrix W of two different postures from n postures BC and the second transformation matrix W AT , after combination, n*(n-1) / 2 transformation matrices W can be obtained AB (ij) ; For n*(n-1) / 2 said transformation matrices W AB (ij) The corresponding same variables are averaged, and the average values ​​of all the same variables are combined into the transformation relationship between the calibration plate coordinate system and the robot arm coordinate system, which is called the third transformation matrix

[0020] Preferably, in step 3.1), the following steps are performed after the robotic arm moves to each posture:

[0021] 3.1.1) The 3D structured light camera projects structured light onto the calibration plate, and collects photos of the landmark structures in the calibration plate projected by the structured light. The computer software records the posture transformation parameters of the robotic arm and the photos of the landmark structures in the calibration plate projected by the structured light. The hand-eye calibration algorithm is used to obtain the transformation relationship between the calibration plate coordinate system and the center point coordinate system of the 3D structured light camera for this posture, which is the first transformation matrix W BC ;

[0022] 3.1.2) Based on the manipulator pose transformation parameters at each pose, obtain the pose representation of the manipulator end center point in the manipulator coordinate system, that is, the transformation relationship between the manipulator end center point coordinate system and the manipulator coordinate system at that pose, which is the second transformation matrix W AT .

[0023] Preferably, in step 3), the number of postures of the 3D structured light camera moving with the robotic arm is 4-25.

[0024] Preferably, the 3D structured light camera in step 3.1.1) projects blue-violet LED light with a wavelength of 490 nm in the form of a 13-24 stripe grating to the calibration plate.

[0025] Preferably, the calibration plate includes a base plate, four spherical calibration parts, a columnar connector for fixedly connecting the base plate and the spherical calibration parts, and a locking part for locking the columnar connector and the base plate. The height of each columnar connector is distributed in an equidistant manner, and all columnar connectors are fixedly arranged on the same side surface of the base plate. The side surface of the base plate where the columnar connector is arranged is provided with a checkerboard.

[0026] Preferably, the columnar connecting member includes a first connecting portion connected to the spherical calibration member and a second connecting portion connected to the substrate. The first connecting portion is provided with a cylindrical groove for the spherical calibration member to sink into. The depth of the groove is greater than the radius of the spherical calibration member, and the inner diameter of the groove is less than or equal to the diameter of the spherical calibration member.

[0027] The system used in the present invention to align the coordinate system of the surgical robot with the coordinate system of the CT machine includes a 3D structured light camera and a calibration plate used in conjunction with the surgical robot console, robotic arm, and CT machine. The 3D structured light camera is fixedly installed with the puncture device installed at the end of the robotic arm and moves with the puncture device as the robotic arm moves.

[0028] To perform registration using the system, one simply pushes the surgical robot and robotic arm equipped with a 3D structured light camera next to the CT machine, places the calibration plate within the CT machine's field of view, and starts the program to automatically complete coordinate registration. The system is simple to operate and easy to learn and use. This greatly simplifies the operation of the surgical robot and significantly reduces the learning and training time for medical staff.

[0029] After applying a 3D structured light camera to a surgical robot, the present invention can quickly and accurately align the coordinate system of the surgical robot with the coordinate system of the CT machine. The alignment accuracy can reach within 1mm, providing accurate positioning and identification for the surgical robot to perform puncture surgery, ensuring the accuracy of the surgery.

[0030] Furthermore, the present invention significantly simplifies the coordinate registration process during robotic surgery through the use of a 3D structured light camera. This process is patient-independent, user-friendly, and significantly reduces the learning and training time for medical staff. Furthermore, the 3D structured light camera, along with the puncture device, is mounted at the end of the robotic arm, reducing the size of the surgical robot and significantly reducing the space occupied by the equipment in the CT operating room. This allows for full use of conventional CT examination rooms, making robotic surgery accessible to a wider range of hospitals. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a flow chart of the method for aligning the surgical robot coordinate system with the CT machine coordinate system in the present invention.

[0032] Figure 2 It is a structural diagram of the system used for aligning the surgical robot coordinate system and the CT machine coordinate system in the present invention.

[0033] Figure 3 It is a schematic diagram of the structure of the 3D structured light camera and the puncture device after being installed in combination in the present invention.

[0034] Figure 4 It is a schematic diagram of the three-dimensional structure of the calibration plate in the present invention.

[0035] Figure 5 It is a schematic diagram of the structure of the checkerboard in the base plate of the calibration board in the present invention.

[0036] Figure 6 It is a schematic cross-sectional structural diagram of four columnar connecting members in the present invention.

[0037] Figure 7 It is a schematic diagram of the working state structure of the system in the present invention.

[0038] Figure 8 This is the working principle of the registration in the present invention Figure 1 .

[0039] Figure 9 This is the working principle of the registration in the present invention Figure 2 . Implementation Method

[0040] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention will be further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings. It should be understood that these descriptions are only exemplary and are not intended to limit the scope of the present invention.

[0041] like Figure 1 、 Figure 2 、 Figure 3 、 Figure 8 and Figure 9 As shown, the method for aligning the coordinate system of the surgical robot and the coordinate system of the CT machine in the present invention is to use a 3D vision system to align the coordinate system of the CT machine with the coordinate system of the robotic arm in the surgical robot, wherein the 3D structured light camera in the 3D vision system moves synchronously with the robotic arm 4 and the puncture device 3 installed at the end of the robotic arm.

[0042] The 3D vision system for aligning the coordinate system of the surgical robot with the coordinate system of the CT machine includes a software part and a hardware part, wherein the software part is combined with the control system of the surgical robot. The specific combination and software program can be implemented by those skilled in the art after a detailed description of the method of the present invention. The hardware part includes a 3D structured light camera 1 mounted on the puncture device 3 at the end of the robotic arm 4 of the surgical robot, and a calibration plate 2 that can be stably placed on the CT machine. The 3D structured light camera 1 and the puncture device 3 are fixedly mounted together via a mounting bracket 32, and are both mounted at the end of the robotic arm 4, and move synchronously with the puncture device 3 as the robotic arm 4 moves. The fixed installation of the 3D structured light camera 1 and the puncture device 3 and the specific structure of the fixed mounting bracket 32 ​​are easy to implement for those skilled in the art and will not be described in detail here.

[0043] like Figure 3 As shown, the 3D structured light camera 1 of the present invention can be split into two parts, including a structured light source 30 and a DDP camera 31, which are respectively installed on both sides of the puncture device 3, so that the puncture needle 5 in the puncture device 3 is located between the structured light source 30 and the DDP camera 31. After the structured light source 30 and the DDP camera 31 are fixedly installed, the light source coverage range of the structured light source 30 and the shooting range of the camera 31 are located below the puncture device 3 in an overlapping manner, which can better locate the puncture position. The 3D structured light camera 1 of the present invention can also be as follows Figure 7 and Figure 9 As shown, it is directly fixedly mounted as a whole on the end of the robotic arm 4 and is arranged parallel (or in parallel) with the puncture device 3.

[0044] like Figure 4As shown, the calibration plate 2 includes a base plate 20, four spherical calibration members 22, four columnar connecting members 21 for fixing the base plate 20 and the spherical calibration members 22, and four locking members 23 for locking the columnar connecting members 21 and the base plate 20.

[0045] The substrate 20 is a square ceramic substrate with a length of 160 mm, a width of 140 mm, and a thickness of 5 mm. A through-hole 25 is provided at each of the four right angles of the ceramic substrate. A marking structure 24 is evenly distributed on one side surface of the ceramic substrate 20 and in the middle of the four through-holes 25. The marking structure 24 is a geometric pattern drawn or printed on the surface of the ceramic substrate 20, such as Figure 5 As shown, the present invention preferably arranges black and white squares alternately to form a checkerboard pattern, and the side length of the black and white squares is 8 mm.

[0046] The columnar connecting parts 21 are preferably formed integrally of polyformaldehyde thermoplastic crystalline polymer (POM) material. A spherical calibration part 22 is fixed above each columnar connecting part 21. The spherical calibration part 22 is made of a material that can clearly image in a CT machine without generating artifacts. An Al2O3 ceramic ball with a diameter of 20 mm is preferably used.

[0047] The materials used for the columnar connecting member 21 and the spherical calibration member 22 are selected such that the density of the spherical calibration member 22 is 1.5-4 times greater than that of the columnar connecting member 21 , and the spherical calibration member 22 can be accurately and clearly identified from the CT image without generating artifacts in the CT image.

[0048] like Figure 6 As shown, the columnar connector 21 includes a first connector 26 connected to the spherical calibration member 22, a second connector 27 connected to the substrate 20, and a connecting column 28 for connecting the first connector 26 and the second connector 27. The first connector 26, the second connector 27, and the connecting column 28 are integrally formed from a polyoxymethylene thermoplastic crystalline polymer material. The heights of the four columnar connectors 21 are different, and the structure and shape of the first connector 26 and the second connector 27 of each columnar connector 21 are the same, and the size is exactly the same. The heights of the connecting columns 28 for connecting the first connector 26 and the second connector 27 are different, and the four connecting columns 28 are arranged in an arithmetic progression, preferably 0 mm, 20 mm, 40 mm, and 60 mm.

[0049] The first connecting portion 26 includes a cylindrical recess 29 for the spherical calibration element 22 to sink into. The depth of the recess 29 is greater than the radius of the spherical calibration element 22 but less than two-thirds of its diameter. In this embodiment, the recess 29 is preferably 21 mm deep and 19.9-20 mm in diameter. Due to the properties of the polyoxymethylene thermoplastic crystalline polymer, the spherical calibration element 22 is slightly clamped when it is sunk into the recess 29, requiring a slight force to enter the recess 29. This allows the center of the spherical calibration element 22 to be completely centered within the recess 29. Once inside the recess 29, the spherical calibration element 22 will not rotate or otherwise move, maintaining its center at the exact center of the recess 29. To ensure smooth entry of the spherical calibration element 22 into the recess 29, a vent hole 19 is provided at the bottom of the recess 29.

[0050] Preferably, the four locking pieces 23 are made of hard rubber support columns, which can ensure that the calibration plate 2 is stable and does not slide when placed on the CT machine.

[0051] The sizes of the checkerboard, columnar connectors 21, and spherical calibration elements 22 in the calibration plate 2 of the present invention, as well as their positions in the calibration plate 2, are precisely controlled, ensuring that the spherical calibration elements 22 can be clearly imaged in the CT machine without artifacts. At the same time, the spherical calibration elements 22 can be stably fixed in the calibration plate, ensuring that the center point of the spherical calibration element 22 has accurate coordinates in the calibration plate coordinate system.

[0052] like Figure 1 、 Figure 7 、 Figure 8 and Figure 9 As shown, the method for aligning the surgical robot coordinate system with the CT machine coordinate system in the present invention is used to align the CT machine coordinate system with the robotic arm coordinate system, and is performed in the following steps:

[0053] 1) The robotic arm 4 with the 3D structured light camera 1 is moved to a predetermined operating area next to the CT machine 6 and fixed therein. In this step, the robotic arm 4 may be pre-activated and moved to a predetermined position.

[0054] 2) The calibration plate 2 is placed on the CT bed of the CT machine 6 and within the range that can be captured by the 3D structured light camera 1 .

[0055] 3) Start the registration program. The robotic arm 4 carrying the 3D structured light camera 1 moves synchronously to the pre-set first pose (set in the surgical robot program) and performs the following steps:

[0056] 3.1) Turn on the structured light source 30 in the 3D structured light camera 1 and project a blue-violet LED light with a wavelength of 490nm onto the calibration plate 2. 20 stripe gratings are formed on the marker structure 24 of the calibration plate 2. The blue-violet LED light is refracted to the DDP camera 31, and the Gray code of the grating stripes is converted into real-time data. A half-precision matching algorithm is performed by software, and then a patch algorithm is used to form a point cloud image. The content distance of the checkerboard in the marker structure 24 of the calibration plate 2 (the distance between the checkerboard corner points) is calculated. Then, based on the true value of the marker structure 24 in the calibration plate 2, a deviation correction calculation is performed to obtain the conversion relationship W between the calibration plate coordinate system and the camera coordinate system in the first pose. BC1 ,

[0057] The transformation relationship between the calibration plate coordinate system and the camera coordinate system is called the first transformation matrix W BC .

[0058] The specific algorithm involved in this step is the hand-eye calibration algorithm, which is a well-known technology, and the specific principles and algorithms will not be described in detail.

[0059] In this step, the projection wavelength of the blue-violet LED light can be between 450nm and 550nm, and can be presented as 13-24 stripe gratings on the calibration plate 2 according to different wavelengths. In this embodiment, a wavelength of 490nm is preferred, and 20 stripe gratings are presented on the calibration plate 2 to facilitate rapid calculation by computer software.

[0060] 3.2) According to the robot arm posture transformation parameters (coordinates x, y, z and angle θ) under each posture x ,θ y ,θ z ), obtain the position representation of the center point of the end of the first-pose manipulator in the manipulator coordinate system, that is, the conversion relationship between the coordinate system of the center point of the end of the manipulator in the first-pose and the manipulator coordinate system, which is the second conversion matrix W AT1 .

[0061] Specifically, the rotation matrix and translation matrix of the transformation matrix are transformed into a 4×4 homogeneous transformation matrix W AT :

[0062]

[0063] 4) Start the robot 4 and move it to the second posture, repeat the above step 3), and obtain the first transformation matrix W of the calibration plate coordinate system and the camera coordinate system in the second posture respectively BC2 , the second transformation matrix W between the center point of the end of the robot 4 and the robot coordinate system AT2 ;

[0064] Repeat this process, moving the robot arm to 4 to 10 different preset postures in sequence, and obtaining the first transformation matrix W at each posture. BCi , is W BC1 , W BC2 , W BC3 , ...W BC10 ; The second transformation matrix W ATi , is: W AT1 , W AT2 , W AT3 , ...W AT10 .

[0065] 5) Obtain the transformation matrix W between the camera coordinate system and the coordinate system of the center point of the end of the robotic arm CT .

[0066] Specifically: select the first transformation matrix W of any two poses (i, j) from the 10 poses in step 4) BCi , W BCj and the second transformation matrix W ATi , W ATj According to the following equation (1), the transformation relationship between the camera coordinate system and the center point coordinate system of the robot end can be obtained, that is, the transformation matrix W CT (ij) .

[0067] W AT (i) W CT (ij) W BC (i) =W AT (j) W CT (ij) W BC (j) (1)

[0068] 6) Obtain the transformation matrix W between the calibration plate coordinate system and the robotic arm coordinate system AB (ij) .

[0069] According to the following equation (2), the conversion relationship between the calibration plate coordinate system and the manipulator coordinate system for the two poses (i, j) is obtained, that is, the conversion matrix is ​​W AB (ij) .

[0070] W AB (ij) =W AT (i) W CT (ij) W BC (i) =W AT(j) W CT (ij) W BC (j) (2)

[0071] 7) Repeat steps 5) and 6) to select the first transformation matrix W of two different postures from the 10 postures BC and the second transformation matrix W AT , after pairwise combination, we can obtain 10*9 / 2=45 transformation matrices W AB (ij) . For 45 transformation matrices W AB (ij) The corresponding same variables are averaged, and the average values ​​of all the same variables are combined into the transformation relationship between the calibration plate coordinate system and the robot arm coordinate system, which is called the third transformation matrix

[0072] It should be noted that 10 poses are preset in this embodiment, which are selected based on the structural dimensions of the calibration plate 2 and the characteristic parameters of the 3D structured light camera 1. The optimal number of poses that can ensure the measurement accuracy and the accuracy of the transformation matrix calculation is selected. The number of poses can be between 4 and 20, depending on the structural dimensions of the calibration plate 2 and the characteristic parameters of the 3D structured light camera 1.

[0073] The same variable refers to the specific variable at each same position in the transformation matrix, such as u ABx ,u ABy ,u ABz wait.

[0074] 8) Control the robotic arm 4 to retract, keep the calibration plate 2 on the CT machine 6, and start the CT machine 6 to perform a close scan on the calibration plate 2.

[0075] The CT impact data of the four spherical calibration pieces 22 on the calibration plate 2 are obtained. The impact data includes the CT values ​​and three-dimensional CT coordinates of all pixels in the image. The spherical center coordinates of the four spherical calibration pieces 22 in the CT coordinate system are calculated using an image recognition algorithm and a spherical center algorithm based on the CT values. The coordinates are expressed as a coordinate matrix B. Combined with the coordinate matrix of the center of the four spherical calibration pieces 22 on the calibration plate 2 The following equation can be obtained:

[0076]

[0077] The coordinate matrix B has been obtained, and the above equation can be solved to calculate the transformation relationship from the CT coordinate system to the calibration plate coordinate system, which is called the fourth transformation matrix

[0078] 9) Obtain the third transformation matrix W between the calibration plate coordinate system and the robotic arm coordinate system AB , the fourth transformation matrix W from the CT coordinate system to the calibration plate coordinate system BD After that, the transformation relationship between the CT machine coordinate system and the robotic arm coordinate system can be obtained according to the following calculation formula (3), which is called the fifth transformation matrix W AD .

[0079]

[0080] The fifth transformation matrix W between the CT coordinate system and the robotic arm coordinate system is obtained AD After that, the coordinate alignment between the CT machine coordinate system and the robotic arm coordinate system is completed, thereby completing the coordinate alignment between the CT machine coordinate system and the surgical robot coordinate system.

[0081] In summary, this invention utilizes a 3D structured light camera mounted on the end of a robotic arm and employs a hand-on-eye calibration method, eliminating the need for a separate binocular camera. This effectively minimizes the impact of various background light sources in the CT room on measurement, while achieving high measurement accuracy. Theoretically, the measurement accuracy can reach 0.001mm, and under the conditions of the example scenario, an accuracy of 0.1mm can be achieved.

Claims

1. A method for registering a surgical robot coordinate system with a CT machine coordinate system, characterized in that: Using a 3D vision system to align the coordinate system of the CT machine with the coordinate system of the robotic arm of the surgical robot, the 3D structured light camera in the 3D vision system moves synchronously with the robotic arm and the puncture device fixedly mounted at the end of the robotic arm; The 3D vision system includes a 3D structured light camera installed at the end of the robotic arm and fixed to the puncture device as a whole, and a calibration plate that can be directly placed on the CT machine and is located within the shooting range of the 3D structured light camera; The method for registering the surgical robot coordinate system with the CT machine coordinate system is performed as follows: 1) Move the robotic arm equipped with the 3D structured light camera into the surgical area next to the CT machine; 2) placing the calibration plate on the CT machine within the range that can be captured by the 3D structured light camera; 3) Initiating a registration procedure, the robotic arm carrying the 3D structured light camera sequentially moves to a plurality of positions. After moving to each position, the 3D structured light camera is activated to project multiple sets of structured light and collect photos of the calibration structure in the calibration plate projected by the structured light. Computer software records the robotic arm transformation parameters for each position and the photos of the calibration structure in the calibration plate. Using a hand-eye calibration algorithm, a transformation relationship between the calibration plate coordinate system and the robotic arm coordinate system is obtained, which is a third transformation matrix. 4) The robotic arm is retracted to its initial position, the calibration plate remains on the CT machine and is started to scan the calibration plate; CT image data of the four spherical calibration elements on the calibration plate are acquired, and the coordinate matrix of the calibration plate with respect to the centers of the four spherical calibration elements is combined to obtain a transformation relationship between the CT coordinate system and the calibration plate coordinate system, which is a fourth transformation matrix; 5) Based on the third transformation matrix between the calibration plate coordinate system and the robotic arm coordinate system and the fourth transformation matrix between the CT machine coordinate system and the calibration plate coordinate system, the transformation relationship between the CT machine coordinate system and the robotic arm coordinate system is obtained as the fifth transformation matrix, and the coordinate alignment of the CT machine coordinate system and the robotic arm coordinate system is completed.

2. The method for registering the surgical robot coordinate system and the CT machine coordinate system according to claim 1, characterized in that: In step 3), perform the following steps: 3.1) Start the registration program. The robotic arm carrying the 3D structured light camera moves to n pre-set different postures in sequence. After moving to each posture, the transformation relationship between the calibration plate coordinate system and the camera coordinate system at each posture is obtained, which is the first transformation matrix W BC The transformation relationship between the center point of the end of the manipulator and the manipulator coordinate system is the second transformation matrix W AT ; 3.2) Select the first transformation matrix W corresponding to two of the poses (i, j) BC and the second transformation matrix W AT , according to the following equation (1), the transformation matrix W between the camera coordinate system and the center point coordinate system of the end of the manipulator is obtained: CT (ij) ; IN AT （i） IN CT (ij) IN BC （i） =W AT （j） IN CT (ij) IN BC （j） (1) 3.3) According to the following equation (2), the two transformation matrices W of the calibration plate coordinate system and the robot arm coordinate system for the two poses (i, j) are obtained: AB (ij) ; IN AB （ij） = In AT （i） IN CT (ij) IN BC （i） =W AT （j） IN CT (ij) IN BC （j） (2) 3.4) Repeat steps 3.2) and 3.3) and select the first transformation matrix W of two different postures from 2n postures BC and the second transformation matrix W AT , after combination, n*(n-1) / 2 transformation matrices W can be obtained AB (ij) ; For n*(n-1) / 2 said transformation matrices W AB (ij) The corresponding same variables are averaged, and the average values ​​of all the same variables are combined into the transformation relationship between the calibration plate coordinate system and the robot arm coordinate system, which is called the third transformation matrix .

3. The method for registering the surgical robot coordinate system and the CT machine coordinate system according to claim 2, characterized in that: In step 3.1), the following steps are performed after the robotic arm moves to each posture: 3.1.1) The 3D structured light camera projects structured light onto the calibration plate, and collects photos of the landmark structures on the calibration plate projected by the structured light. Computer software records the posture transformation parameters of the robotic arm and the photos of the landmark structures on the calibration plate projected by the structured light. The hand-eye calibration algorithm is used to obtain the transformation relationship between the calibration plate coordinate system and the 3D structured light camera center point coordinate system for this posture, which is the first transformation matrix W BC ; 3.1.2) Based on the manipulator pose transformation parameters at each pose, obtain the pose representation of the manipulator end center point in the manipulator coordinate system, that is, the transformation relationship between the manipulator end center point coordinate system and the manipulator coordinate system at that pose, which is the second transformation matrix W AT .

4. The method for registering the surgical robot coordinate system and the CT machine coordinate system according to claim 2, wherein: In step 3), the number of postures of the 3D structured light camera as the robotic arm moves is an even number between 4 and 20.

5. The method for registering the surgical robot coordinate system and the CT machine coordinate system according to claim 3, characterized in that: The 3D structured light camera in step 3.1.1) projects blue-violet LED light with a wavelength of 490 nm in the form of a 13-24 stripe grating onto the calibration plate.

6. The method for registering a surgical robot coordinate system and a CT machine coordinate system according to any one of claims 1 to 5, characterized in that: The calibration plate includes a base plate, four spherical calibration parts, a columnar connector for fixedly connecting the base plate and the spherical calibration parts, and a locking part for locking the columnar connector and the base plate. The height of each columnar connector is distributed in an equidistant manner, and all columnar connectors are fixedly arranged on the same side surface of the base plate. The side surface of the base plate where the columnar connector is arranged is provided with a checkerboard.

7. The method for registering the surgical robot coordinate system and the CT machine coordinate system according to claim 6, characterized in that: The columnar connecting member includes a first connecting portion connected to the spherical calibration member and a second connecting portion connected to the substrate. The first connecting portion is provided with a cylindrical groove for the spherical calibration member to sink into. The depth of the groove is greater than the radius of the spherical calibration member, and the inner diameter of the groove is less than or equal to the diameter of the spherical calibration member.

8. A system for use in the method for registering a surgical robot coordinate system with a CT machine coordinate system as described in any one of claims 1 to 7, comprising a 3D structured light camera and a calibration plate used in conjunction with a surgical robot console, a robotic arm, and a CT machine, characterized in that: The 3D structured light camera is fixedly installed together with the puncture device installed at the end of the robotic arm, and moves together with the puncture device as the robotic arm moves.

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