Six-dimensional force sensor calibration method, system and equipment

Abstract

The invention belongs to the field of force sensor calibration, and particularly discloses a six-dimensional force sensor calibration method, system and equipment, and the method comprises the steps: obtaining the actual output data of a six-dimensional force sensor under different working conditions where calibration forces are applied: forces Fx, Fy and Fz and moments Mx, My and Mz in the X-axis direction, the Y-axis direction and the Z-axis direction; the working conditions comprise at least one of the conditions that the clamping jaw rotates to a plurality of preset angles on the XZ plane in the closed state, the clamping jaw rotates to a plurality of preset angles on the YZ plane in the closed state, and the clamping jaw is symmetrically opened to a plurality of preset angles along the Z axis on the XZ plane; based on different values and different working conditions of the calibration force, determining theoretical output data of the sensor when the calibration force of different values is applied; obtaining calibration parameters based on actual output data and theoretical output data of the sensor; the calibration parameters are used for calibrating actual output data when the six-dimensional force sensor works. According to the invention, the application effect of the six-dimensional force sensor on middle clamp instruments is improved.

Description

Technical Field

[0001] The present application relates to the field of force sensor calibration, and more specifically, to a six-dimensional force sensor calibration method, system, and device. Background Art

[0002] The calibration of traditional six-axis force sensors is usually carried out in an independent environment, but in precision applications such as laparoscopic surgical machinery, measurement errors may occur after the sensor is installed, affecting the actual accuracy. In the prior art, the calibration of six-axis force sensors is usually carried out in an ideal laboratory environment, and a static known force is applied to the sensor through a standard loading platform to obtain its output signal and fit the calibration parameters. However, this type of method generally has the following shortcomings: First, after the sensor is integrated into the forceps-type surgical instrument, it is easily affected by factors such as screw preload, structural assembly errors, and elastic deformation of the instrument body, resulting in an offset in the force transmission path. The calibration parameters obtained in the laboratory cannot accurately reflect the response characteristics of the sensor under actual working conditions, thereby affecting the measurement accuracy; Secondly, traditional calibration methods mainly target a limited number of loading directions or fixed postures, and lack comprehensive coverage of the mechanical characteristics of the instrument under multi-angle and multi-posture working conditions, resulting in insufficient representativeness of the obtained calibration data and difficulty in meeting application requirements in complex operating scenarios; in addition, traditional methods mostly use linear models for error compensation, which makes it difficult to deal with compound errors caused by structural coupling or nonlinear response, limiting the measurement performance of the sensor in high-precision scenarios.

[0003] In summary, the existing calibration methods have problems such as unstable accuracy, poor versatility, and disconnection with actual working conditions. There is an urgent need for a calibration method that can be executed after sensor integration, can cover multiple working conditions, and has the ability to compensate for nonlinear errors, so as to improve the application effect and measurement reliability of six-dimensional force sensors in clamp-type instruments. Summary of the Invention

[0004] In response to the defects of the existing technology, the purpose of this application is to provide a six-axis force sensor calibration method, system and equipment, aiming to solve the problems of traditional six-axis force sensor calibration methods being out of assembly state, insufficient working condition coverage and limited error compensation capabilities.

[0005] To achieve the above objectives, in a first aspect, the present application provides a six-axis force sensor calibration method, wherein the six-axis force sensor is provided on a clamp-type instrument, the clamp-type instrument includes a clamp jaw, and the clamp jaw is rotatable about a Z axis. The six-axis force sensor is used to measure the force and torque applied to the clamp, and the method includes: Obtain the actual output data of the six-axis force sensor under different working conditions of applied calibration force; the actual output data includes: the force F in the X-axis, Y-axis and Z-axis directions x 、F y 、Fz and moment M x 、M y 、M z The different working conditions include: the jaws rotating to a plurality of preset angles in the XZ plane in a closed state, the jaws rotating to a plurality of preset angles in the YZ plane in a closed state, and the jaws opening symmetrically along the Z axis in the XZ plane to a plurality of preset angles; the calibration force refers to the calibrated force; Determining theoretical output data of the six-dimensional force sensor when different calibration forces are applied based on different values ​​of the calibration force and different working conditions; wherein the theoretical output data is related to at least one of an angle of the jaws relative to the Z axis in a closed state or an angle of the jaws symmetrically opened relative to the Z axis in an open state, a value of the calibration force, and a force arm of the calibration force; Calibration parameters are obtained based on the actual output data and theoretical output data of the six-dimensional force sensor; the calibration parameters are used to calibrate the actual output data of the six-dimensional force sensor when it is working.

[0006] The calibration process provided in this application is carried out after the six-dimensional force sensor is assembled to a clamp-type instrument. It truly considers the impact of actual working conditions such as instrument structure coupling and preload force on the measurement results, and collects all-round, multi-posture, and multi-channel calibration data through a variety of typical loading conditions, thereby comprehensively improving the calibration accuracy of the six-dimensional force sensor.

[0007] In an optional implementation, the working condition includes a first working condition, wherein the first working condition is: the clamping jaws are rotated to a plurality of preset angles in the XZ plane in a closed state; Determine the theoretical output data of the six-axis force sensor when the calibration force is applied, including: Get the angle of the gripper relative to the Z axis , determine the length L of the force arm from the calibration force application point to the clamping jaw fulcrum; the calibration force is applied in the normal direction of the closed clamping jaw in the XZ plane, and the six-dimensional force sensor is set at the clamping jaw fulcrum; based on and the standard force value F, determine the theoretical value F of the X-axis force output of the six-dimensional force sensor under the first working condition x理论 for And the theoretical value of Z-axis force F z理论 for , Y-axis force theoretical value F y理论 is 0; Based on L and F, determine the theoretical value M of the Y-axis torque output of the six-dimensional force sensor under the first working condition. y理论 F L, Z-axis torque theoretical value M z理论 and the theoretical value of the X-axis moment M x理论 Both are 0.

[0008] In an optional implementation, the working condition includes a second working condition, wherein the second working condition is: the clamping jaws are rotated to a plurality of preset angles in the YZ plane in a closed state; Determine the theoretical output data of the six-axis force sensor when the calibration force is applied, including: Get the angle of the gripper relative to the Z axis , determine the length L of the force arm from the calibration force application point to the clamping jaw fulcrum; the calibration force is applied in the normal direction of the closed clamping jaw in the YZ plane, and the six-dimensional force sensor is set at the clamping jaw fulcrum; based on and the standard force value F, determine the theoretical value F of the Y-axis force output of the six-dimensional force sensor under the second working condition y理论 for And the theoretical value of Z-axis force F z理论 for , X-axis force theoretical value F x理论 is 0; Based on L and F, determine the theoretical value M of the X-axis torque output by the six-dimensional force sensor under the second working condition x理论 F L, Z-axis torque theoretical value M z理论 and the theoretical value of the Y-axis moment M y理论 Both are 0.

[0009] In an optional implementation, the working condition includes a third working condition, wherein the third working condition is: the clamping jaws are opened symmetrically along the Z axis in the XZ plane to a plurality of preset angles; Determine the theoretical output data of the six-axis force sensor when the calibration force is applied, including: Get the angle between the two gripper arms of the gripper when they are symmetrically opened relative to the Z axis , the calibration force F is applied to one gripper arm, and its direction is perpendicular to the XZ plane; Determine the length L of the force arm from the calibration force application point to the clamping jaw fulcrum, where the six-dimensional force sensor is arranged; Determine the theoretical value F of the Y-axis force output of the six-dimensional force sensor under the third working condition y理论 F, the theoretical value of X-axis force F x理论 And the theoretical value of Z-axis force F z理论 All are 0; Based on L, F and , determine the theoretical value M of the X-axis torque output by the six-dimensional force sensor under the third working condition x理论 F L , the theoretical value of the Z-axis moment M z理论 F L , Y-axis torque theoretical value M y理论 is 0.

[0010] In an optional implementation, the working condition includes a third working condition, wherein the third working condition is: the clamping jaws are opened symmetrically along the Z axis in the XZ plane to a plurality of preset angles; Determine the theoretical output data of the six-axis force sensor when the calibration force is applied, including: Get the angle between the two gripper arms of the gripper when they are symmetrically opened relative to the Z axis , the calibration force F is applied to one gripper arm, and its direction is parallel to the X-axis; Determine the length L of the force arm from the calibration force application point to the clamping jaw fulcrum, where the six-dimensional force sensor is arranged; Determine the theoretical value F of the X-axis force output of the six-dimensional force sensor under the third working condition x理论 F, the theoretical value of Y-axis force F y理论 And the theoretical value of Z-axis force F z理论 All are 0; Based on L, F and , determine the theoretical value M of the Y-axis torque output by the six-dimensional force sensor under the third working condition y理论 F L , the theoretical value of the Z-axis moment M z理论 and the theoretical value of the X-axis moment M x理论 Both are 0.

[0011] In an optional implementation, the calibration parameters include: a calibration matrix K and an offset vector B; the actual output data S of the six-dimensional force sensor F / M And theoretical output data S 理论 The mapping relationship between them is: S 理论 =S F / M ×K+B.

[0012] In a second aspect, the present application provides a six-axis force sensor calibration system, wherein the six-axis force sensor is provided on a clamp-type instrument, wherein the clamp-type instrument includes a clamping jaw, wherein the clamping jaw is rotatable about a Z axis, and the six-axis force sensor is used to measure the force and torque applied to the clamp. The system includes: The actual output data acquisition module is used to obtain the actual output data of the six-dimensional force sensor under different working conditions of the applied calibration force; the actual output data includes: the force F in the X-axis, Y-axis and Z-axis directions x 、F y 、F z and moment M x 、M y 、M zThe different working conditions include: the jaws rotating to a plurality of preset angles in the XZ plane in a closed state, the jaws rotating to a plurality of preset angles in the YZ plane in a closed state, and the jaws opening symmetrically along the Z axis in the XZ plane to a plurality of preset angles; the calibration force refers to the calibrated force; a theoretical output data acquisition module, configured to determine theoretical output data of the six-dimensional force sensor when different calibration forces are applied based on different values ​​of the calibration force and different working conditions; the theoretical output data being related to at least one of the angle of the jaws relative to the Z axis in a closed state or the angle of the jaws symmetrically opened relative to the Z axis in an open state, the value of the calibration force, and the force arm of the calibration force; The calibration module is used to obtain calibration parameters based on the actual output data and theoretical output data of the six-dimensional force sensor; the calibration parameters are used to calibrate the actual output data of the six-dimensional force sensor when it is working.

[0013] In an optional implementation, the working condition includes a first working condition, wherein the first working condition is: the clamping jaws are rotated to a plurality of preset angles in the XZ plane in a closed state; The theoretical output data acquisition module obtains the angle of the gripper relative to the Z axis , determine the arm length L from the calibration force application point to the clamping jaw fulcrum; the calibration force is applied in the normal direction of the closed clamping jaw in the XZ plane, and the six-dimensional force sensor is set at the clamping jaw fulcrum; based on and the standard force value F, determine the theoretical value F of the X-axis force output of the six-dimensional force sensor under the first working condition x理论 for And the theoretical value of Z-axis force F z理论 for , Y-axis force theoretical value F y理论 =0; Based on L and F, determine the theoretical value M of the Y-axis torque output of the six-dimensional force sensor under the first working condition y理论 F L, Z-axis torque theoretical value M z理论 and the theoretical value of the X-axis moment M x理论 Both are 0.

[0014] In an optional implementation, the working condition includes a second working condition, wherein the second working condition is: the clamping jaws are rotated to a plurality of preset angles in the YZ plane in a closed state; The theoretical output data acquisition module obtains the angle of the gripper relative to the Z axis , determine the arm length L from the calibration force application point to the clamping jaw fulcrum; the calibration force is applied in the normal direction of the closed clamping jaw in the YZ plane, and the six-dimensional force sensor is set at the clamping jaw fulcrum; based on and the standard force value F, determine the theoretical value F of the Y-axis force output of the six-dimensional force sensor under the second working conditiony理论 for And the theoretical value of Z-axis force F z理论 for , X-axis force theoretical value F x理论 =0; Based on L and F, determine the theoretical value M of the X-axis torque output of the six-dimensional force sensor under the second working condition x理论 F L, Z-axis torque theoretical value M z理论 and the theoretical value of the Y-axis moment M y理论 Both are 0.

[0015] In a third aspect, the present application provides an electronic device comprising: at least one memory for storing programs; and at least one processor for executing the programs stored in the memory. When the program stored in the memory is executed, the processor is used to execute the method described in the first aspect or any possible implementation of the first aspect.

[0016] In a fourth aspect, the present application provides a computer-readable storage medium, which stores a computer program. When the computer program runs on a processor, the processor executes the method described in the first aspect or any possible implementation of the first aspect.

[0017] In a fifth aspect, the present application provides a computer program product, which, when executed on a processor, enables the processor to execute the method described in the first aspect or any possible implementation of the first aspect.

[0018] It can be understood that the beneficial effects of the second to fifth aspects mentioned above can be found in the relevant description of the first aspect mentioned above, and will not be repeated here.

[0019] In general, the above technical solutions conceived by this application have the following beneficial effects compared with the existing technologies: This application provides a six-axis force sensor calibration method, system, and device. The calibration process is performed after the six-axis force sensor is assembled into a clamp-type instrument. This method accurately reflects the impact of actual operating conditions, such as instrument structural coupling and preload, on measurement results. This improves the calibration accuracy of the six-axis force sensor and effectively compensates for assembly errors. By collecting omnidirectional, multi-posture, and multi-channel calibration data under various typical loading conditions (such as jaw rotation and symmetrical opening in the XZ and YZ planes), the representativeness and stability of the model fitting are improved.

[0020] This application provides a six-dimensional force sensor calibration method, system, and device. This calibration process can utilize methods such as least squares or neural networks, adapting to sensor calibration requirements under complex conditions such as nonlinearity and coupled interference, thereby enhancing measurement accuracy. The method provided in this application is applicable to a variety of forceps instruments, enabling repeatable calibration processes. It exhibits excellent versatility and consistency, facilitating widespread and standardized implementation. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is one of the flow charts of the six-dimensional force sensor calibration method provided in the embodiment of the present application; Figure 2 This is a schematic diagram of the first working condition and calibration force of the embedded device provided in an embodiment of the present application; Figure 3 This is a schematic diagram of the second working condition and calibration force of the embedded device provided in an embodiment of the present application; Figure 4 This is one of the schematic diagrams of the third working condition and calibration force of the embedded device provided in the embodiment of the present application; Figure 5 This is the second schematic diagram of the third working condition and calibration force of the embedded device provided in the embodiment of the present application; Figure 6 This is the second flow chart of the six-axis force sensor calibration method provided in the embodiment of the present application; Figure 7 Schematic diagram of the structure of the six-axis force sensor calibration system provided in an embodiment of the present application; Figure 8 It is a structural diagram of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solutions and advantages of this application more clear, the following further describes this application in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0023] The term "and / or" as used herein describes an association between related objects, indicating that three possible relationships exist. For example, "A and / or B" can represent: A exists alone, A and B exist simultaneously, or B exists alone. The symbol " / " as used herein indicates that the related objects are in an "or" relationship, for example, A / B means either A or B.

[0024] In the embodiments of this application, words such as "exemplary" or "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design described as "exemplary" or "for example" in the embodiments of this application should not be interpreted as being preferred or advantageous over other embodiments or designs. Rather, the use of words such as "exemplary" or "for example" is intended to present the relevant concepts in a concrete manner.

[0025] The embodiments of the present application are described below in conjunction with the drawings in the embodiments of the present application.

[0026] The embodiment of the present application proposes a calibration method for a six-dimensional force sensor after assembly. After the sensor is integrated into a laparoscopic embedded instrument, calibration is performed directly in its working state to compensate for errors caused by installation. This method can more realistically reflect the force conditions of the sensor in the embedded instrument and improve the stability and accuracy of the measurement. A commercial standard force loading device is used to ensure that the application of force conforms to the actual operating environment of the laparoscopic instrument. At the same time, the error compensation model is combined to optimize the measurement data of the sensor. This method is suitable for high-precision application scenarios such as laparoscopic surgical robots and minimally invasive embedded instruments. It can effectively improve the accuracy of force feedback and enhance the safety and stability of remote control.

[0027] This calibration method is designed specifically for forceps and inlay instruments, and can accurately measure their forces in six degrees of freedom, thereby improving measurement accuracy and versatility. For example, forceps are one of the most widely used instrument categories in laparoscopic and minimally invasive surgery, covering a variety of types such as tissue clamps, hemostatic forceps, electrocoagulation forceps, needle holders, and retraction forceps. Therefore, the six-dimensional force sensor calibration method for this large category of instruments can effectively improve the force measurement accuracy of different types of clamps, ensure the stability and consistency of force measurement data, and provide high-quality data support for the optimized design of inlay instruments. This method not only improves the accuracy and safety of force feedback during surgery, but also promotes the intelligent development of minimally invasive surgery, improves the accuracy of laparoscopic surgery, and contributes to future data-driven surgical quality assessment and personalized medicine.

[0028] Figure 1 This is a flow chart of a six-axis force sensor calibration method provided in an embodiment of the present application. The six-axis force sensor is provided on a clamp-type instrument, which includes a clamping jaw that can rotate about the Z axis. The six-axis force sensor is used to measure the force and torque applied to the clamp. The method includes: Step S101, obtaining the actual output data of the six-axis force sensor under different working conditions of applying the calibration force; the actual output data includes: the force F in the X-axis, Y-axis and Z-axis directions x 、F y 、F z and moment M x 、M y 、M z; The different working conditions include: the clamp rotates to multiple preset angles in the XZ plane when the clamp is closed, rotates to multiple preset angles in the YZ plane when the clamp is closed, and the clamp opens symmetrically along the Z axis in the XZ plane to at least one of multiple preset angles.

[0029] It can be understood that the above-mentioned calibration force refers to the calibrated force.

[0030] Step S102, based on different values ​​of the calibration force and different working conditions, determine the theoretical output data of the six-dimensional force sensor when different values ​​of calibration force are applied; the theoretical output data is related to at least one of the angle of the clamping jaw relative to the Z axis in the closed state or the angle of the clamping jaw symmetrically opened relative to the Z axis in the open state, the value of the calibration force and the force arm of the calibration force.

[0031] Step S103 , obtaining calibration parameters based on the actual output data and theoretical output data of the six-dimensional force sensor; the calibration parameters are used to calibrate the actual output data of the six-dimensional force sensor when it is working.

[0032] In an optional implementation, the working condition includes a first working condition, wherein the first working condition is: the clamping jaws are rotated to a plurality of preset angles in the XZ plane in a closed state; Determine the theoretical output data of the six-axis force sensor when the calibration force is applied, including: Get the angle of the gripper relative to the Z axis , determine the length L of the force arm from the calibration force application point to the clamping jaw fulcrum; the calibration force is applied in the normal direction of the closed clamping jaw in the XZ plane, and the six-dimensional force sensor is set at the clamping jaw fulcrum; based on and the standard force value F, determine the theoretical value F of the X-axis force output of the six-dimensional force sensor under the first working condition x理论 for And the theoretical value of Z-axis force F z理论 for , Y-axis force theoretical value F y理论 is 0; Based on L and F, determine the theoretical value M of the Y-axis torque output of the six-dimensional force sensor under the first working condition. y理论 F L, Z-axis torque theoretical value M z理论 and the theoretical value of the X-axis moment M x理论 Both are 0.

[0033] Specifically, if Figure 2 As shown in the figure, when the force-applying platform applies a vertical force F, the force is decomposed into Fx' (tangential) and Fz' (normal) in the clamp surface coordinate system.

[0034] The components (Fx', Fz') in the clamp surface coordinate system are converted to the theoretical values ​​(Fx'', Fz'') in the sensor coordinate system through the coordinate system rotation transformation matrix. The mathematical relationship is:

[0035] For example, a high-precision uniaxial force sensor may be installed vertically at the force application point as a standard value measuring device for the normal force F.

[0036] Furthermore, the distal motor of the clamp can be used to drive the end jaw of the clamp to rotate around the vertical axis Z axis in the horizontal plane of the XZ axis by an angle θ, and the clamp position is locked after the rotation. After that, the six-dimensional force sensor of the clamp-like instrument installed at the fulcrum of the clamp is obtained after the normal force F is applied, and the X, Y, and Z direction component force readings F are output in real time. X 、F y 、F Z (signal to be calibrated), and real-time output of X, Y, and Z direction moment readings M x 、M y and M z ; and use the above method to calculate the corresponding theoretical output data.

[0037] More specifically, under the above working conditions, multiple sets of theoretical output data and actual output data can be obtained by changing the values ​​of θ and F.

[0038] In one example, the following steps are specifically included: (1) Angle coverage: Control the clamp to rotate in a fixed step size (e.g., 10°) within the range of 0° to 180°, covering all circumferential positions.

[0039] (2) Force loading: At each angle θ, a step-by-step increasing normal force F (such as 0N, 1N, 2N…10N) is applied.

[0040] (3) Data synchronization recording: 1) The reference sensor outputs force value F (standard value); 2) Measured component F of the six-dimensional force sensor X 、F y 、F Z 、M x 、M y and M z ; 3) Calculate the corresponding theoretical output data.

[0041] In an optional implementation, the working condition includes a second working condition, wherein the second working condition is: the clamping jaws are rotated to a plurality of preset angles in the YZ plane in a closed state; Determine the theoretical output data of the six-axis force sensor when the calibration force is applied, including: Get the angle of the gripper relative to the Z axis , determine the length L of the force arm from the calibration force application point to the clamping jaw fulcrum; the calibration force is applied in the normal direction of the closed clamping jaw in the YZ plane, and the six-dimensional force sensor is set at the clamping jaw fulcrum; based on and the standard force value F, determine the theoretical value F of the Y-axis force output of the six-dimensional force sensor under the second working condition y理论 for And the theoretical value of Z-axis force F z理论 for , X-axis force theoretical value F x理论 is 0; Based on L and F, determine the theoretical value M of the X-axis torque output by the six-dimensional force sensor under the second working condition. x理论 F L, Z-axis torque theoretical value M z理论 and the theoretical value of the Y-axis moment M y理论 Both are 0.

[0042] Specifically, if Figure 3 As shown in the second working condition, the cable motor can be driven to rotate the embedded device 90° around the Z axis, aligning the original Y direction with the X / Z plane. The X / Z direction calibration process is reused to apply the normal force and collect the Y direction force component to establish the Y direction calibration model.

[0043] In an optional implementation, the above working condition includes a third working condition, wherein the third working condition is: the clamping jaws are opened symmetrically along the Z axis in the XZ plane to a plurality of preset angles; Determine the theoretical output data of the six-axis force sensor when the calibration force is applied, including: Get the angle between the two gripper arms of the gripper when they are symmetrically opened relative to the Z axis , the calibration force F is applied to one gripper arm, and its direction is perpendicular to the XZ plane; Determine the length L of the force arm from the calibration force application point to the clamping jaw fulcrum, where the six-dimensional force sensor is arranged; Determine the theoretical value F of the Y-axis force output of the six-dimensional force sensor under the third working condition y理论 F, the theoretical value of X-axis force F x理论 And the theoretical value of Z-axis force F z理论 All are 0; Based on L, F and , determine the theoretical value M of the X-axis torque output by the six-dimensional force sensor under the third working condition x理论 F L , the theoretical value of the Z-axis moment M z理论 F L , Y-axis torque theoretical value M y理论 is 0.

[0044] Specifically, if Figure 4 As shown, the distance from the force application point (at the midpoint of the clamp) to the fulcrum is recorded as L, and a force F is applied in a direction perpendicular to the XZ plane (i.e. parallel to the y-axis). Measuring torque M x :When a force F perpendicular to the XZ plane is applied at the force application point, the moment M in the X direction of the sensor is x In general, the position of the force can be equivalently moved to the equivalent point (the direction of the force is still perpendicular to the XZ plane, and the magnitude of the force remains unchanged). At this time, the length of the force arm is d x =Lcosθ, so the theoretical value of the torque is M x =Fd x =FLcosθ, so when the jaws open, θ becomes larger, the length of the lever arm becomes smaller, and the torque becomes smaller. Therefore, by changing the angle value of the jaw opening, M x The data of different sizes in different directions are used to calibrate the torque in the X direction of the sensor.

[0045] Measuring torque M z :When a force F perpendicular to the XZ plane is applied at the force application point, the moment M in the Z direction of the sensor is Z In general, the position of the force can be equivalently moved to the equivalent point (the direction of the force is still perpendicular to the XZ plane, and the magnitude of the force remains unchanged). At this time, the length of the force arm is d z =Lsinθ, torque M z =FLsinθ. Therefore, when the jaws open, θ increases, the length of the lever arm increases, and the torque increases. Therefore, by changing the jaw opening angle, we collect data of varying magnitudes in the Mz direction, thereby calibrating the sensor's torque in the Z direction.

[0046] In an optional implementation, the working condition includes a third working condition, wherein the third working condition is: the clamping jaws are opened symmetrically along the Z axis in the XZ plane to a plurality of preset angles; Determine the theoretical output data of the six-axis force sensor when the calibration force is applied, including: Get the angle between the two gripper arms of the gripper when they are symmetrically opened relative to the Z axis , the calibration force F is applied to one gripper arm, and its direction is parallel to the X-axis; Determine the length L of the force arm from the calibration force application point to the clamping jaw fulcrum, where the six-dimensional force sensor is arranged; Determine the theoretical value F of the X-axis force output of the six-dimensional force sensor under the third working condition x理论 F, the theoretical value of Y-axis force F y理论 And the theoretical value of Z-axis force Fz理论 All are 0; Based on L, F and , determine the theoretical value M of the Y-axis torque output by the six-dimensional force sensor under the third working condition y理论 F L , the theoretical value of the Z-axis moment M z理论 and the theoretical value of the X-axis moment M x理论 Both are 0.

[0047] Specifically, if Figure 5 As shown, we only need to change the direction of the applied force to be always parallel to the x-axis direction of the sensor, and then we can measure the magnitude of the torque M. y = Fd y =FLcosθ.

[0048] In an optional implementation, the calibration parameters include: a calibration matrix K and an offset vector B; the actual output data S of the six-dimensional force sensor F / M And theoretical output data S 理论 The mapping relationship between them is: S 理论 =S F / M ×K+B. Usually, the above calibration parameters are used to calibrate the actual output data S of the six-axis force sensor. F / M Calibrate the sensor so that the value after calibration is equal to or close to the theoretical output value, thus completing the calibration of the six-dimensional force sensor.

[0049] In the specific practical application process, the correction of the real-time measurement data of the six-dimensional force sensor is: F / M ×K+B and then output; S F / M For real-time measurement data.

[0050] For example, see Figure 6 As shown, the specific process of the above calibration method provided in the embodiment of the present application includes the following steps: Step 1: Fix the 6-axis force sensor to be calibrated on the force calibration platform, ensure that the installation is stable and the sensor coordinate system is aligned with the platform coordinate system. Use the distal motor of the embedded instrument to drive the end of the clamp to rotate it around the vertical axis in the XZ plane to the preset angle. (The angle value is accurately calculated by the motor encoder feedback signal) and the clamp position is locked to ensure the clamp angle in the subsequent calibration process Remain unchanged.

[0051] Step 2: The force loading device applies a normal force of (0N, 1N, 2N...10N) to the center of mass of the clamp and calculates the theoretical force F generated by the sensor to be calibrated. X 、F Z and M YAt the same time, the sensor to be calibrated will also generate force F in the X, Y, and Z directions due to the force F X , torque M Y Heli F Z Use the host computer to record the actual value of the sensor to be calibrated at the angle The theoretical signal and actual signal of the sensor to be calibrated under different normal forces.

[0052] Step 3: Adjust the clamp rotation angle to (In 10° steps). At each angle Repeat the force loading and data acquisition process in step 2 to ensure that the full range of 0°~180° in the XZ plane is covered, and obtain theoretical and actual value data sets under multiple angles and multiple force values.

[0053] Step 4: Use the distal motor of the inlay instrument to drive the inlay instrument axis to rotate 90 degrees, so that the clamp switches from the XZ plane to the YZ plane. Repeat the process of steps 2 and 3 to complete the multi-angle ( ) under data collection.

[0054] Step 5: Use the distal motor of the surgical instrument to drive the clamping jaws to move at different angles in the XZ plane. The grippers are opened symmetrically to form a spatial force arm L from the gripper's force application point to the gripper's fulcrum. A force F is applied perpendicular to the XZ plane (i.e., along the Y axis), which generates a component torque on the sensor's X and Z axes. The theoretical torque values ​​in the X and Z axes are then calculated, where θ represents the symmetrical opening angle of the gripper relative to the Z axis. By adjusting the angle β and applying a step-by-step increasing normal force F at each angle (e.g., 0N, 1N, 2N, ..., 10N), the actual output torque M of the sensor to be calibrated is simultaneously recorded. x 、M z The theoretical output value and the actual measured value are calculated respectively to establish the calibration model of the torque in the X and Z axis directions.

[0055] Step 6: Maintain symmetrical opening angles of the jaws In the state, adjust the loading direction so that the loading force F is always applied along the X-axis direction, that is, parallel to the X-axis direction of the sensor coordinate system. The force application point is located at the center of mass of the middle of the gripper, and the distance between it and the gripper fulcrum is recorded as L. This force exerts a Y-axis torque on the sensor. Where θ is the symmetrical opening angle of the unilateral gripper relative to the Z-axis. By adjusting the angle γ and applying a step-by-step increasing loading force F at each angle (such as 0N, 1N, 2N, …, 10N), the theoretical torque value in the Y-axis direction is calculated, and the actual output torque M of the sensor is recorded simultaneously. yThe theoretical and actual value data under the corresponding working conditions are stored to establish the torque calibration model in the Y-axis direction.

[0056] Step 7: Based on the collected multi-condition data, a six-dimensional force / torque error compensation model is established and the output is calibrated. An optimization algorithm is used to solve the calibration matrix and offset, bringing the sensor's actual output close to the theoretical value. After verifying the accuracy and generalization of the calibration matrix and confirming that it meets the requirements, the six-dimensional force sensor calibration is complete.

[0057] Specifically, the error compensation model can adopt one of the following two methods: 1. Linear modeling method: Construct a unified linear calibration model based on the original output of the six-dimensional sensor Input, theoretical output To establish the following relationship:

[0058] in is the calibration matrix, is the offset vector; or according to actual needs, the force and torque are modeled separately, and two sub-models are constructed to fit them separately. and aisle.

[0059] 2. Nonlinear fitting method: When the sensor output is limited by nonlinear structural deformation, assembly coupling interference, or strong coupling between force / torque channels, a neural network method can be used to establish an end-to-end nonlinear error compensation model. This method uses the six-dimensional raw output as input and the theoretical value as the supervision signal. The compensation function can be obtained through training as follows: ,in This represents a multi-layer feedforward neural network model with weight parameters θ. It can contain multiple neurons (e.g., more than 100 neurons) and uses Reluctant Unified Unit (ReLU) or Tanh as the activation function. The training process is optimized by minimizing the error loss function (such as the mean square error (MSE)) between the actual and theoretical outputs, using iterative optimizers such as Adam to achieve convergence. Network training can be completed offline, and the parameters are fixed and loaded during system runtime, supporting online real-time compensation after calibration. This method offers enhanced fitting and generalization capabilities, making it particularly suitable for force / torque compensation requirements in complex nonlinear sensor conditions or high-precision operation scenarios.

[0060] It is understandable that for the calibration of six-axis force sensors for clamps and clamps, both traditional least squares decoupling can be used to improve computational efficiency, and BP neural network algorithms can be used to compensate for nonlinear errors and improve measurement accuracy. For different types of clamps, the appropriate method can be selected based on real-time requirements, computing power, error characteristics, and other factors to ensure calibration accuracy, versatility, and stability, thereby improving the application effect of six-axis force sensors in clamps.

[0061] Figure 7 A six-dimensional force sensor calibration system is provided in the embodiment of the present application, such as Figure 7 As shown, the system includes: The actual output data acquisition module 710 is configured to acquire actual output data of the six-dimensional force sensor under different working conditions in which a calibration force is applied; the actual output data includes components of the forces Fx, Fy, and Fz and the moments Mx, My, and Mz in the X-axis, Y-axis, and Z-axis directions; the different working conditions include at least one of: the jaws being rotated to a plurality of preset angles in the XZ plane in a closed state, the jaws being rotated to a plurality of preset angles in the YZ plane in a closed state, and the jaws being symmetrically opened to a plurality of preset angles in the XZ plane along the Z axis; a theoretical output data acquisition module 720 for determining theoretical output data of the six-dimensional force sensor when different calibration forces are applied based on different values ​​of the calibration force and different operating conditions; the theoretical output data being related to at least one of the angle of the jaws relative to the Z axis in a closed state or the angle of the jaws symmetrically opened relative to the Z axis in an open state, the value of the calibration force, and the force arm of the calibration force; The calibration module 730 is used to obtain calibration parameters based on the actual output data and theoretical output data of the six-axis force sensor; the calibration parameters are used to calibrate the actual output data of the six-axis force sensor when it is working.

[0062] Specifically, the working conditions include a first working condition, a second working condition and a third working condition. The first working condition is: the clamp rotates to multiple preset angles in the XZ plane when the clamp is closed; the second working condition is: the clamp rotates to multiple preset angles in the YZ plane when the clamp is closed; the third working condition is: the clamp opens symmetrically along the Z axis in the XZ plane to multiple preset angles.

[0063] The theoretical output data acquisition module 720 determines the theoretical output data of the six-dimensional force sensor when different numerical calibration forces are applied, including: Get the angle of the gripper relative to the Z axis , determine the arm length L from the calibration force application point to the clamping jaw fulcrum; the calibration force is applied in the normal direction of the closed clamping jaw in the XZ plane, and the six-dimensional force sensor is set at the clamping jaw fulcrum; based on and the standard force value F, determine the theoretical value F of the X-axis force output of the six-dimensional force sensor under the first working condition x理论 for And the theoretical value of Z-axis force F z理论 for , Y-axis force theoretical value F y理论 =0; Based on L and F, determine the theoretical value M of the Y-axis torque output of the six-dimensional force sensor under the first working condition y理论 F L, Z-axis torque theoretical value M z理论 and the theoretical value of the X-axis moment M x理论 Both are 0.

[0064] Get the angle of the gripper relative to the Z axis , determine the arm length L from the calibration force application point to the clamping jaw fulcrum; the calibration force is applied in the normal direction of the closed clamping jaw in the YZ plane, and the six-dimensional force sensor is set at the clamping jaw fulcrum; based on and the standard force value F, determine the theoretical value F of the Y-axis force output of the six-dimensional force sensor under the second working condition y理论 for And the theoretical value of Z-axis force F z理论 for , X-axis force theoretical value F x理论 =0; Based on L and F, determine the theoretical value M of the X-axis torque output of the six-dimensional force sensor under the second working condition x理论 F L, Z-axis torque theoretical value M z理论 and the theoretical value of the Y-axis moment M y理论 Both are 0.

[0065] Get the angle between the two gripper arms of the gripper when they are symmetrically opened relative to the Z axis , a calibration force F is applied to a claw arm, and its direction is perpendicular to the XZ plane; the length L of the force arm from the calibration force application point to the claw fulcrum is determined, and the six-axis force sensor is set at the claw fulcrum; the theoretical value F of the Y-axis force theoretically output by the six-axis force sensor under the third working condition is determined y理论 F, the theoretical value of X-axis force F x理论 And the theoretical value of Z-axis force F z理论 are all 0; based on L, F and , determine the theoretical value M of the X-axis torque output by the six-dimensional force sensor under the third working condition x理论 F L , the theoretical value of the Z-axis moment M z理论 F L , Y-axis torque theoretical value M y理论 is 0.

[0066] Get the angle between the two gripper arms of the gripper when they are symmetrically opened relative to the Z axis , a calibration force F is applied to a claw arm in a direction parallel to the X-axis; the length L of the force arm from the calibration force application point to the claw fulcrum is determined, and the six-axis force sensor is set at the claw fulcrum; the theoretical value F of the X-axis force theoretically output by the six-axis force sensor under the third working condition is determined x理论 F, the theoretical value of Y-axis force F y理论 And the theoretical value of Z-axis force F z理论 are all 0; based on L, F and , determine the theoretical value M of the Y-axis torque output by the six-dimensional force sensor under the third working condition y理论 F L , the theoretical value of the Z-axis moment M z理论 and the theoretical value of the X-axis moment M x理论 Both are 0.

[0067] It should be understood that the above-mentioned system is used to execute the method in the above-mentioned embodiment. The implementation principle and technical effect of the corresponding program module in the system are similar to those described in the above-mentioned method. The working process of the system can refer to the corresponding process in the above-mentioned method and will not be repeated here.

[0068] Based on the method in the above embodiment, the embodiment of the present application provides an electronic device, such as Figure 8 As shown, the electronic device may include: a processor 810, a communication interface 820, a memory 830, and a communication bus 840, wherein the processor 810, the communication interface 820, and the memory 830 communicate with each other via the communication bus 840. The processor 810 may call the logic instructions in the memory 830 to execute the method in the above embodiment.

[0069] In addition, the logic instructions in the aforementioned memory 830 can be implemented in the form of a software functional unit and, when sold or used as an independent product, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, or the portion that contributes to the prior art, or the portion of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes a number of instructions for enabling a computer device (which can be a personal computer, server, or network device, etc.) to execute all or part of the steps of the method described in each embodiment of the present application.

[0070] Based on the method in the above embodiment, an embodiment of the present application provides a computer-readable storage medium, which stores a computer program. When the computer program runs on a processor, the processor executes the method in the above embodiment.

[0071] Based on the method in the above embodiment, an embodiment of the present application provides a computer program product. When the computer program product runs on a processor, the processor executes the method in the above embodiment.

[0072] It is understood that the processor in the embodiments of the present application may be a central processing unit (CPU), other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field programmable gate arrays (FPGA), other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. The general-purpose processor may be a microprocessor or any conventional processor.

[0073] The method steps in the embodiments of the present application can be implemented by hardware or by a processor executing software instructions. The software instructions can be composed of corresponding software modules, which can be stored in random access memory (RAM), flash memory, read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), registers, hard disks, mobile hard disks, CD-ROMs, or any other form of storage medium known in the art. An exemplary storage medium is coupled to the processor so that the processor can read information from the storage medium and write information to the storage medium. Of course, the storage medium can also be an integral part of the processor. The processor and storage medium can be located in an ASIC.

[0074] The above embodiments can be implemented in whole or in part using software, hardware, firmware, or any combination thereof. When implemented using software, they can be implemented in whole or in part in the form of a computer program product. The computer program product comprises one or more computer instructions. When loaded and executed on a computer, the computer program instructions fully or partially produce the processes or functions described in the embodiments of this application. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted via the computer-readable storage medium. The computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium accessible by a computer or a data storage device such as a server or data center that integrates one or more available media. The available medium can be magnetic media (e.g., floppy disk, hard disk, tape), optical media (e.g., DVD), or semiconductor media (e.g., solid-state drive (SSD)).

[0075] It will be understood that the various numerical numbers involved in the embodiments of the present application are merely distinctions for the convenience of description and are not intended to limit the scope of the embodiments of the present application.

[0076] It is easy for those skilled in the art to understand that the above is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application should be included in the scope of protection of the present application.

Claims

1. A six-axis force sensor calibration method, wherein the six-axis force sensor is provided on a clamp-type instrument, the clamp-type instrument including a clamp jaw, the clamp jaw being rotatable about a Z axis, and the six-axis force sensor is used to measure the force and torque applied to the clamp, characterized in that: Methods include: Obtain the actual output data of the six-dimensional force sensor under different working conditions of applied calibration force; The actual output data includes: the force F in the X-axis, Y-axis and Z-axis directions x 、F y 、F z and moment M x 、M y 、M z The different working conditions include: the jaws rotating to a plurality of preset angles in the XZ plane in a closed state, the jaws rotating to a plurality of preset angles in the YZ plane in a closed state, and the jaws opening symmetrically along the Z axis in the XZ plane to a plurality of preset angles; the calibration force refers to the calibrated force; Determining theoretical output data of the six-dimensional force sensor when different calibration forces are applied based on different values ​​of the calibration force and different working conditions; the theoretical output data is related to at least one of an angle of the jaws relative to the Z axis in a closed state or an angle of the jaws symmetrically opened relative to the Z axis in an open state, a calibration force value, and a calibration force arm; Calibration parameters are obtained based on the actual output data and theoretical output data of the six-dimensional force sensor; the calibration parameters are used to calibrate the actual output data of the six-dimensional force sensor when it is working.

2. The method according to claim 1, characterized in that The working conditions include a first working condition, wherein the first working condition is: the gripper is rotated to a plurality of preset angles in the XZ plane in a closed state; Determine the theoretical output data of the six-axis force sensor when the calibration force is applied, including: Get the angle of the gripper relative to the Z axis , determine the length L of the force arm from the calibration force application point to the clamping jaw fulcrum; the calibration force is applied in the normal direction of the closed clamping jaw in the XZ plane, and the six-dimensional force sensor is set at the clamping jaw fulcrum; based on and the standard force value F, determine the theoretical value F of the X-axis force output of the six-dimensional force sensor under the first working condition x理论 for And the theoretical value of Z-axis force F z理论 for , Y-axis force theoretical value F y理论 is 0; Based on L and F, determine the theoretical value M of the Y-axis torque output of the six-dimensional force sensor under the first working condition. y理论 F L, Z-axis torque theoretical value M z理论 and the theoretical value of the X-axis moment M x理论 Both are 0.

3. The method according to claim 1, characterized in that The working condition includes a second working condition, wherein the second working condition is: the clamping jaws are rotated to a plurality of preset angles in the YZ plane in a closed state; Determine the theoretical output data of the six-axis force sensor when the calibration force is applied, including: Get the angle of the gripper relative to the Z axis , determine the length L of the force arm from the calibration force application point to the clamping jaw fulcrum; the calibration force is applied in the normal direction of the closed clamping jaw in the YZ plane, and the six-dimensional force sensor is set at the clamping jaw fulcrum; based on and the standard force value F, determine the theoretical value F of the Y-axis force output of the six-dimensional force sensor under the second working condition y理论 for And the theoretical value of Z-axis force F z理论 for , X-axis force theoretical value F x理论 is 0; Based on L and F, determine the theoretical value M of the X-axis torque output by the six-dimensional force sensor under the second working condition. x理论 F L, Z-axis torque theoretical value M z理论 and the theoretical value of the Y-axis moment M y理论 Both are 0.

4. The method according to claim 1, wherein The working condition includes a third working condition, wherein the clamping jaws are opened symmetrically along the Z axis in the XZ plane to a plurality of preset angles; Determine the theoretical output data of the six-axis force sensor when the calibration force is applied, including: Get the angle between the two gripper arms of the gripper when they are symmetrically opened relative to the Z axis , the calibration force F is applied to one gripper arm, and its direction is perpendicular to the XZ plane; Determine the length L of the force arm from the calibration force application point to the clamping jaw fulcrum, where the six-dimensional force sensor is arranged; Determine the theoretical value F of the Y-axis force output of the six-dimensional force sensor under the third working condition y理论 F, the theoretical value of X-axis force F x理论 And the theoretical value of Z-axis force F z理论 All are 0; Based on L, F and , determine the theoretical value M of the X-axis torque output by the six-dimensional force sensor under the third working condition x理论 F L , the theoretical value of the Z-axis moment M z理论 F L , Y-axis torque theoretical value M y理论 is 0.

5. The method according to claim 1, wherein The working condition includes a third working condition, wherein the clamping jaws are opened symmetrically along the Z axis in the XZ plane to a plurality of preset angles; Determine the theoretical output data of the six-axis force sensor when the calibration force is applied, including: Get the angle between the two gripper arms of the gripper when they are symmetrically opened relative to the Z axis , the calibration force F is applied to one gripper arm, and its direction is parallel to the X-axis; Determine the length L of the force arm from the calibration force application point to the clamping jaw fulcrum, where the six-dimensional force sensor is arranged; Determine the theoretical value F of the X-axis force output of the six-dimensional force sensor under the third working condition x理论 F, the theoretical value of Y-axis force F y理论 And the theoretical value of Z-axis force F z理论 All are 0; Based on L, F and , determine the theoretical value M of the Y-axis torque output by the six-dimensional force sensor under the third working condition y理论 F L , the theoretical value of the Z-axis moment M z理论 and the theoretical value of the X-axis moment M x理论 Both are 0.

6. The method according to any one of claims 1 to 5, characterized in that The calibration parameters include: calibration matrix K and offset vector B; actual output data S of the six-dimensional force sensor F / M And theoretical output data S 理论 The mapping relationship between them is: S 理论 =S F / M ×K+B.

7. A six-axis force sensor calibration system, wherein the six-axis force sensor is provided on a clamp-type instrument, the clamp-type instrument including a clamp jaw, the clamp jaw being rotatable about a Z axis, and the six-axis force sensor is used to measure the force and torque applied to the clamp, characterized in that: The system includes: An actual output data acquisition module is used to obtain actual output data of the six-dimensional force sensor under different working conditions where a calibration force is applied; The actual output data includes: the force F in the X-axis, Y-axis and Z-axis directions x 、F y 、F z and moment M x 、M y 、M z The different working conditions include: the jaws rotating to a plurality of preset angles in the XZ plane in a closed state, the jaws rotating to a plurality of preset angles in the YZ plane in a closed state, and the jaws opening symmetrically along the Z axis in the XZ plane to a plurality of preset angles; the calibration force refers to the calibrated force; a theoretical output data acquisition module, configured to determine theoretical output data of the six-dimensional force sensor when different calibration forces are applied based on different values ​​of the calibration force and different working conditions; the theoretical output data being related to at least one of the angle of the jaws relative to the Z axis in a closed state or the angle of the jaws symmetrically opened relative to the Z axis in an open state, the calibration force value, and the calibration force arm; The calibration module is used to obtain calibration parameters based on the actual output data and theoretical output data of the six-dimensional force sensor; the calibration parameters are used to calibrate the actual output data of the six-dimensional force sensor when it is working.

8. The system according to claim 7, characterized in that The working conditions include a first working condition, wherein the first working condition is: the clamping jaws are rotated to a plurality of preset angles in the XZ plane in a closed state; The theoretical output data acquisition module obtains the angle of the gripper relative to the Z axis , determine the arm length L from the calibration force application point to the clamping jaw fulcrum; the calibration force is applied in the normal direction of the closed clamping jaw in the XZ plane, and the six-dimensional force sensor is set at the clamping jaw fulcrum; based on and the standard force value F, determine the theoretical value F of the X-axis force output of the six-dimensional force sensor under the first working condition x理论 for And the theoretical value of Z-axis force F z理论 for , Y-axis force theoretical value F y理论 =0; Based on L and F, determine the theoretical value M of the Y-axis torque output of the six-dimensional force sensor under the first working condition y理论 F L, Z-axis torque theoretical value M z理论 and the theoretical value of the X-axis moment M x理论 Both are 0.

9. The system according to claim 7, wherein: The working condition includes a second working condition, wherein the second working condition is: the clamping jaws are rotated to a plurality of preset angles in the YZ plane in a closed state; The theoretical output data acquisition module obtains the angle of the gripper relative to the Z axis , determine the arm length L from the calibration force application point to the clamping jaw fulcrum; the calibration force is applied in the normal direction of the closed clamping jaw in the YZ plane, and the six-dimensional force sensor is set at the clamping jaw fulcrum; based on and the standard force value F, determine the theoretical value F of the Y-axis force output of the six-dimensional force sensor under the second working condition y理论 for And the theoretical value of Z-axis force F z理论 for , X-axis force theoretical value F x理论 =0; Based on L and F, determine the theoretical value M of the X-axis torque output of the six-dimensional force sensor under the second working condition x理论 F L, Z-axis torque theoretical value M z理论 and the theoretical value of the Y-axis moment M y理论 Both are 0.

10. An electronic device, characterized in that: include: at least one memory for storing a computer program; At least one processor is used to execute the program stored in the memory. When the program stored in the memory is executed, the processor is used to execute the method according to any one of claims 1 to 6.

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