A path planning method for automatic measurement of catheters in an intelligent catheter production line

Abstract

The present invention relates to a path planning method for automatic catheter measurement in an intelligent catheter production line. The method comprises the following steps: constructing a rotational reference plane for the catheter; planning a new path for the measuring machine and measuring the catheter connecting cylinder to obtain the actual measured value of the catheter connecting cylinder at the position change; calculating the position offset and angular rotation of the catheter based on the rotational reference plane and the actual measured value of the catheter connecting cylinder; and utilizing the position offset and angular rotation to optimize the path of all subsequent measurement points. This path planning method for automatic catheter measurement in an intelligent catheter production line aims to address the problem of poor repeatability in coordinate measurement during intelligent catheter production.

Description

Technical Field

[0001] The present invention relates to the technical field of precise coordinate measurement of catheters, and in particular to a path planning method for automatic measurement of catheters in an intelligent catheter production line. Background Art

[0002] The intelligent production process for catheters includes multiple steps, including bending, cutting, cleaning, welding, and precision testing. A three-dimensional coordinate measuring machine (CMM) is a key component of the catheter production line, responsible for final product inspection. The catheters are transported through various stages using robotic arms. However, due to inconsistent clamping force between fixtures in various processing equipment and buffer stations, swaying during cleaning, and low repeatability of the robotic arms, the repeatability of the CMM fixtures during transport of the catheters through these multiple stages is extremely poor, making precise coordinate measurement impossible. This often results in unmeasured or collision problems, severely impacting catheter production efficiency. The underlying cause is that the catheters rotate more than 3° and translate more than 2mm on the CMM fixtures. This prevents the precision coordinate measurement system from following the planned measurement path, preventing the acquisition of surface point information and causing the catheter's automatic measurement system to fail. This failure of automatic measurement represents a crucial missing link in the catheter production line, impeding the realization of intelligent, automated production of catheters.

[0003] Therefore, whether the measurement path of the catheter can be automatically optimized during the measurement process is one of the key technologies for achieving precise measurement of the catheter when the posture repeatability positioning accuracy is poor. It is also a key factor in whether the entire catheter production line can achieve full process automation from processing to measurement.

[0004] Therefore, the inventors provide a path planning method for automatic measurement of catheters in an intelligent catheter production line. Summary of the Invention

[0005] (1) Technical problems to be solved

[0006] The embodiment of the present invention provides a path planning method for automatic measurement of catheters in an intelligent catheter production line, which solves the technical problem of poor repeatability of coordinate measurement during the intelligent production of catheters.

[0007] (2) Technical solution

[0008] The present invention provides a path planning method for automatic measurement of catheters in an intelligent catheter production line, comprising the following steps:

[0009] Constructing a rotational reference plane for the catheter;

[0010] Plan a new path for the measuring machine and measure the cylinder of the catheter connecting section to obtain the actual measurement value of the cylinder of the catheter connecting section that has changed position;

[0011] Calculating the position offset and angular rotation of the catheter based on the rotation reference plane and the actual measured value of the cylindrical portion of the catheter connection section;

[0012] The position offset and the angular rotation are used to optimize the paths of all subsequent measurement points.

[0013] Furthermore, the construction of the rotation reference plane of the catheter specifically includes the following steps:

[0014] Using a trial-and-teach method to measure the first axis information of the catheter clamping section cylinder and the second axis information of the catheter connecting section cylinder;

[0015] Performing an intersecting cylinder operation on the catheter clamping section cylinder and the catheter connecting section cylinder to obtain a first axis intersection point of the two cylinders;

[0016] The rotation reference plane is constructed using a fitting algorithm based on the first axis information, the second axis information and the first axis intersection point.

[0017] Furthermore, the measurement of the first axis information of the catheter clamping section cylinder and the second axis information of the catheter connecting section cylinder using the trial teaching method is specifically as follows:

[0018] Collecting three-dimensional information (X1, Y1, Z1) of cylindrical surface points on the catheter clamping section cylinder, with the number of collected points being greater than 6 and evenly distributed on the cylinder, and obtaining the first axis information through a least squares fitting algorithm;

[0019] The three-dimensional information (X2, Y2, Z2) of the cylindrical surface points is collected on the cylinder of the catheter connection section. The number of collected points is greater than 6 and is evenly distributed on the cylinder. The first axis information is obtained through the least squares fitting algorithm.

[0020] Furthermore, the new path of the measuring machine is planned and the cylinder of the conduit connection section is measured to obtain the actual measurement value of the cylinder of the conduit connection section with the position change, specifically:

[0021] The path search method is used to search and measure the cylinder of the catheter connection section, and the actual measurement value of the cylinder of the catheter connection section is measured.

[0022] Furthermore, the path search method is used to search and measure the cylinder of the conduit connection section to obtain the actual measurement value of the cylinder of the conduit connection section, which specifically includes the following steps:

[0023] The measuring device moves to the initial position of the first measuring point above the cylinder of the conduit connection section;

[0024] Measuring a fixed distance moved by the device from the initial position along the negative direction of the Z axis and recording the position information;

[0025] The measurement information of the cylinder of the conduit connection section is updated according to the position information to achieve the measurement of the cylinder of the conduit connection section.

[0026] Furthermore, the calculation of the position offset and the angular rotation of the catheter based on the rotation reference plane and the actual measured value of the cylindrical portion of the catheter connection section specifically includes the following steps:

[0027] Intersecting the position-changed catheter connecting section cylinder with the catheter clamping section cylinder to obtain a second axis intersection of the two cylinders;

[0028] Using the position-changed catheter connecting section cylinder, the catheter clamping section cylinder, and the intersection of the second axis, a rotated plane is constructed;

[0029] determining a rotation angle of the catheter based on the rotation reference plane and the rotated plane;

[0030] The displacement of the catheter is determined based on the intersection of the first and second axes.

[0031] Furthermore, the path optimization of all subsequent measurement points is achieved by utilizing the position offset and the angular rotation, specifically:

[0032] According to the position offset and the angular rotation, the planned measurement path points are rotated around the axis of the clamping section catheter and offset at the same time to obtain optimized path points.

[0033] Furthermore, before constructing the rotation reference plane of the catheter, the method further includes:

[0034] The catheter is placed in the measurement space of the non-contact measurement system.

[0035] (3) Beneficial effects

[0036] In summary, the present invention establishes a catheter rotation and translation model based on the measurement characteristics of the catheter, designs a tentative measurement process for the connection section, and uses the position offset and angular rotation to optimize the path of all subsequent measurement points, thereby achieving high-precision automatic measurement under conditions of poor repeatability and optimizing all subsequent measurement points, ultimately achieving the purpose of realizing automatic catheter measurement and reducing economic losses. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments of the present invention. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0038] Figure 1 This is a flow chart of a path planning method for automatic measurement of a catheter in an intelligent catheter production line provided by an embodiment of the present invention;

[0039] Figure 2 is a schematic structural diagram of a catheter provided by an embodiment of the present invention;

[0040] Figure 3 This is a schematic diagram of a catheter reference plane provided by an embodiment of the present invention.

[0041] In the picture:

[0042] 1-catheter clamping section; 2-catheter connecting section; 3-first axis intersection; 4-rotation reference plane. DETAILED DESCRIPTION

[0043] The following detailed description of the embodiments of the present invention is provided in conjunction with the accompanying drawings and examples. The detailed description of the following embodiments and the accompanying drawings are intended to illustrate the principles of the present invention and are not intended to limit the scope of the present invention. That is, the present invention is not limited to the described embodiments and covers any modifications, replacements, and improvements to the parts, components, and connection methods without departing from the spirit of the present invention.

[0044] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments in this application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0045] Figure 1 1 is a flow chart of a path planning method for automatic measurement of a catheter in an intelligent catheter production line provided by an embodiment of the present invention. The method may include the following steps:

[0046] S100, constructing a rotation reference plane of the catheter;

[0047] S200, planning a new path for the measuring machine and measuring the cylinder of the connecting section of the catheter to obtain an actual measurement value of the cylinder of the connecting section of the catheter that has changed position;

[0048] S300, calculating the position offset and angular rotation of the catheter based on the actual measurement value of the rotation reference plane and the cylindrical portion of the catheter connection section;

[0049] S400: Optimize the paths of all subsequent measurement points using the position offset and the angular rotation.

[0050] In the above embodiment, a catheter rotation and translation model is established based on the measurement characteristics of the catheter, and a tentative measurement process for the connection section is designed to optimize all subsequent measurement points, ultimately achieving the purpose of automatic catheter measurement and reducing economic losses.

[0051] This planning method constructs a catheter rotation reference plane and uses it as a basis for path optimization. A new path is planned using the measuring machine to measure the catheter's connecting cylinder, obtaining the actual measured value of the cylinder's position change. Based on the actual measurement of the connecting cylinder, the algorithm automatically calculates the position offset and angular rotation of the catheter. Finally, this position offset and angular rotation are used to optimize the path for all subsequent measurement points, achieving high-precision automatic measurement even with poor repeatability. This method is suitable for optimizing catheter paths with position offsets less than 3 mm and rotation angles less than ±7°.

[0052] As a preferred embodiment, in step S100, constructing the rotation reference plane of the catheter specifically includes the following steps:

[0053] S101, using a trial-teaching method to measure the first axis information of the cylinder of the catheter clamping section and the second axis information of the cylinder of the catheter connecting section;

[0054] S102, performing an intersecting cylinder operation on the catheter clamping section cylinder and the catheter connecting section cylinder to obtain a first axis intersection point of the two cylinders;

[0055] S103 , constructing a rotation reference plane using a fitting algorithm based on the first axis information, the second axis information and the intersection of the first axis.

[0056] Specifically, the above provides a specific method for constructing the rotation reference plane of the catheter.

[0057] As a preferred embodiment, the first axis information of the catheter clamping section cylinder and the second axis information of the catheter connecting section cylinder are measured using a trial teaching method, specifically:

[0058] Collect 3D information (X1, Y1, Z1) of the cylindrical surface points on the clamping section of the catheter. The number of collected points is greater than 6 and evenly distributed on the cylinder. The first axis information is obtained through the least squares fitting algorithm.

[0059] The three-dimensional information (X2, Y2, Z2) of the cylindrical surface points is collected on the cylinder of the catheter connection section. The number of collected points is greater than 6 and is evenly distributed on the cylinder. The first axis information is obtained through the least squares fitting algorithm.

[0060] As a preferred embodiment, in step S200, a new path of the measuring machine is planned and the cylinder of the connecting section of the catheter is measured to obtain the actual measurement value of the cylinder of the connecting section of the catheter with a changed position, specifically:

[0061] The path search method is used to search and measure the cylinder of the catheter connection section, and the actual measurement value of the cylinder of the catheter connection section is measured.

[0062] As a preferred embodiment, a path search method is used to search and measure the cylinder of the catheter connection section to obtain the actual measurement value of the cylinder of the catheter connection section. The measurement method specifically includes the following steps:

[0063] S201, the measuring device moves to the initial position of the first measuring point above the cylinder of the catheter connection section;

[0064] S202, measuring the fixed distance the device moves from the initial position along the negative direction of the Z axis and recording the position information;

[0065] S203: Update the measurement information of the cylinder of the catheter connection section according to the position information to achieve measurement of the cylinder of the catheter connection section.

[0066] In the above embodiment, in step S202, the measuring device moves slowly for a fixed distance in the negative direction of the Z axis at its initial position. In the first case, the probe has a measurement value and the device records the position information. In the second case, the probe has no measurement value, returns to the initial position, moves a fixed distance in the negative direction of the X axis, and then moves in the negative direction of the Z axis. The probe has a measurement value and records the position information.

[0067] As a preferred embodiment, in step S300, the position offset and angular rotation of the catheter are calculated based on the rotation reference plane and the actual measurement value of the cylindrical portion of the catheter connection section, which specifically includes the following steps:

[0068] S301, intersecting the catheter connecting section cylinder and the catheter clamping section cylinder after the position change to obtain a second axis intersection of the two cylinders;

[0069] S302, constructing a rotated plane using the position-changed catheter connecting section cylinder, the catheter clamping section cylinder, and the intersection of the second axis;

[0070] S303, determining the rotation angle of the catheter based on the rotation reference plane and the plane after rotation;

[0071] S304: Determine the displacement of the catheter according to the intersection of the first axis and the intersection of the second axis.

[0072] As a preferred embodiment, in step S400, the position offset and the angular rotation are used to optimize the paths of all subsequent measurement points, specifically:

[0073] According to the position offset and the angular rotation, the planned measurement path points are rotated around the axis of the clamping section catheter and offset at the same time to obtain the optimized path points.

[0074] As a preferred embodiment, in step S100, before constructing the rotation reference plane of the catheter, the method further includes: placing the catheter in a measurement space of a non-contact measurement system.

[0075] Example 1

[0076] For a certain type of catheter with a diameter of 60 mm, the path planning process is as follows:

[0077] 1) Using the teaching method, obtain the axis information of the clamping section and the connecting section of the catheter; the axis information of the clamping section is (95.958, 60.785, -90.568, 1.001, 0, 0), and the axis information of the connecting section is (35.965, 110.79, -90.55, -0.196006757, 0.980602488, 0.000333378), and record the measurement and evaluation process;

[0078] 2) The two axes intersect to obtain the point (45.962, 60.786, -90.567, -0.0001, 0, 0.9998);

[0079] 3) The two-axis information constructs the reference plane and obtains the plane information (50.962, 60.786, -90.567, 0, 0, 1.00001);

[0080] 4) After the catheter deviates, the axis information of the connecting section is measured using the search path method, which is (36.858, 108.798, -85.55, -0.038875956, 0.262804093, -0.964065697). Intersecting with the axis information of the clamping section is (43.96, 60.788, -90.569, 0, 0, 1.000015).

[0081] 5) The calculated displacement offset is 2.000002 and the angular rotation is 5.945°;

[0082] 6) The measured path point is translated on the axis of the clamping section catheter by an offset amount and rotated around the axis by an angle rotation amount to obtain the optimized path point.

[0083] It should be noted that the various embodiments in this specification are described in a progressive manner. References to the same or similar parts between the various embodiments are sufficient. Each embodiment focuses on the differences from the other embodiments. The present invention is not limited to the specific steps and structures described above and shown in the figures. Furthermore, for the sake of brevity, detailed descriptions of known methods and technologies are omitted here.

[0084] The above are merely embodiments of the present application and are not intended to limit the present application. Various modifications and variations are possible for those skilled in the art without departing from the scope of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application should be included within the scope of the claims of the present application.

Claims

1. A path planning method for automatic measurement of catheters in an intelligent catheter production line, characterized in that: The method comprises the following steps: Constructing the rotational reference plane of the catheter; Plan a new path for the measuring machine and measure the cylinder of the catheter connecting section to obtain the actual measurement value of the cylinder of the catheter connecting section that has changed position; Calculating the position offset and angular rotation of the catheter based on the rotation reference plane and the actual measured value of the cylindrical portion of the catheter connection section; Utilizing the position offset and the angular rotation to optimize the paths of all subsequent measurement points; The construction of the rotation reference plane of the catheter specifically includes the following steps: Using a trial-and-teach method to measure the first axis information of the catheter clamping section cylinder and the second axis information of the catheter connecting section cylinder; Performing an intersecting cylinder operation on the catheter clamping section cylinder and the catheter connecting section cylinder to obtain a first axis intersection point of the two cylinders; constructing the rotation reference plane using a fitting algorithm based on the first axis information, the second axis information and the first axis intersection point; The method of measuring the first axis information of the cylinder of the catheter clamping section and the second axis information of the cylinder of the catheter connecting section by the trial teaching method is specifically as follows: Collect 3D information of cylindrical surface points on the catheter clamping section cylinder ( X 1, Y 1, Z 1) The number of acquisition points is greater than 6 and is evenly distributed on the cylinder. The first axis information is obtained by the least squares fitting algorithm; Collect 3D information of cylindrical surface points on the cylinder of the catheter connection section ( X 2, Y 2, Z 2) The number of acquisition points is greater than 6 and evenly distributed on the cylinder, and the second axis information is obtained through the least squares fitting algorithm; Calculating the position offset and angular rotation of the catheter based on the rotation reference plane and the actual measured value of the cylindrical portion of the catheter connection section specifically includes the following steps: Intersecting the position-changed catheter connecting section cylinder with the catheter clamping section cylinder to obtain a second axis intersection of the two cylinders; Constructing a rotated plane using the position-changed catheter connecting section cylinder, the catheter clamping section cylinder, and the intersection of the second axis; Determining an angular rotation amount of the catheter based on the rotation reference plane and the rotated plane; The position offset of the catheter is determined according to the intersection point of the first axis and the intersection point of the second axis.

2. The path planning method for automatic measurement of catheters in a catheter intelligent production line according to claim 1, characterized in that: The new path of the measuring machine is planned and the cylinder of the conduit connection section is measured to obtain the actual measurement value of the cylinder of the conduit connection section with the position change, specifically: The path search method is used to search and measure the cylinder of the catheter connection section, and the actual measurement value of the cylinder of the catheter connection section is measured.

3. The path planning method for automatic measurement of catheters in a catheter intelligent production line according to claim 2, characterized in that: The path search method is used to search and measure the cylinder of the conduit connection section to obtain the actual measurement value of the cylinder of the conduit connection section, which specifically includes the following steps: The measuring device moves to the initial position of the first measuring point above the cylinder of the conduit connection section; The measuring device moves from the initial position along Z The fixed distance that the axis moves in the negative direction and the position information is recorded; The measurement information of the cylinder of the conduit connection section is updated according to the position information to achieve the measurement of the cylinder of the conduit connection section.

4. The path planning method for automatic measurement of catheters in a catheter intelligent production line according to claim 1, characterized in that: The path optimization of all subsequent measurement points is achieved by utilizing the position offset and the angular rotation, specifically: According to the position offset and the angular rotation, the planned measurement path points are rotated around the axis of the clamping section catheter and offset at the same time to obtain optimized path points.

5. The path planning method for automatic measurement of catheters in a catheter intelligent production line according to claim 1, characterized in that: Before constructing the rotation reference plane of the catheter, the method further includes: The catheter is placed in the measurement space of the non-contact measurement system.

Images