WO2023029922A1

WO2023029922A1 - Method and system for limiting movement area of robot

Info

Publication number: WO2023029922A1
Application number: PCT/CN2022/111535
Authority: WO
Inventors: 张逸凌; 刘星宇
Original assignee: 北京长木谷医疗科技有限公司; 张逸凌
Priority date: 2021-09-03
Filing date: 2022-08-10
Publication date: 2023-03-09
Also published as: CN113842217B; CN113842217A

Abstract

Disclosed in the present application are a method and system for limiting a movement area of a robot. The method comprises: establishing a stiffness-damping model of a virtual spring according to a displacement offset between an initial position and an actual position of an actuator at a robot arm tail end of a robot in each of the directions of multiple degrees of freedom; and setting the respective stiffness values of the virtual springs in the directions of the multiple degrees of freedom, so as to limit the movement of the actuator in a pre-planned target area. In the present application, the stiffness in each of the directions of multiple degrees of freedom is set by using a stiffness-damping model of a virtual spring, such that motions in the directions of the multiple degrees of freedom are restrained. When an external force is applied to the multiple degrees of freedom, displacement is very small in the direction of the degree of freedom where the stiffness is large, such that displacement may not even occur. In this way, an actuator can be limited in a target area, thereby preventing a patient from being hurt by the actuator deviating from the target area.

Description

Method and system for limiting motion area of robot

Cross References to Related Applications

This application claims the priority of the Chinese patent application with application number 202111035714.2 and titled "Method and System for Limiting Robot Movement Area" filed on September 3, 2021, which is incorporated herein by reference in its entirety.

technical field

The present application relates to the technical field of medical devices, and in particular, relates to a method and system for defining a movement area of a robot.

Background technique

In the existing operation, when a robot is used for assistance, the doctor's hand supports the mechanical arm of the robot to operate. During the operation, due to the negligence of the operation, active or passive force may be exerted too much where it should not be, so that the saw blade at the end of the mechanical arm exceeds the predetermined operating area, thereby causing unnecessary pain to the patient. harm.

Contents of the invention

The main purpose of the present application is to provide a method and system for limiting the movement area of a robot, so as to limit the actuator at the end of the mechanical arm within the target area, thereby improving safety.

In order to achieve the above purpose, according to one aspect of the present application, a method for defining the motion area of a robot is provided, including:

According to the displacement offset between the initial position and the actual position of the actuator at the end of the robotic arm of the robot in multiple degrees of freedom directions, the stiffness-damping model of the virtual spring is established;

Stiffness values of each of the virtual springs in directions of multiple degrees of freedom are set to limit the movement of the actuator to a pre-planned target area.

In one embodiment, the direction in which the actuator cuts into the target area is marked as the depth direction, the direction within the target area and perpendicular to the depth direction is marked as the lateral direction, and the direction perpendicular to the target area is marked as vertical direction;

Set the stiffness values of each of the virtual springs in directions of multiple degrees of freedom, including:

In the translation degree of freedom direction, set the stiffness value of the virtual spring in the depth direction, the stiffness value of the virtual spring in the lateral direction, and the stiffness value of the virtual spring in the vertical direction;

The stiffness value of the virtual spring in the depth direction is equal to or smaller than the stiffness value of the virtual spring in the transverse direction;

The stiffness value of the virtual spring in the transverse direction is smaller than the stiffness value of the virtual spring in the vertical direction;

The stiffness value of the virtual spring in the depth direction and the stiffness value of the virtual spring in the transverse direction are both less than or equal to the first translation preset stiffness threshold, and the stiffness value of the virtual spring in the vertical direction is greater than or equal to the second Shift the preset stiffness threshold.

In one embodiment, setting the stiffness values of each of the virtual springs in directions of multiple degrees of freedom includes:

In the direction of the degree of freedom of rotation, set the stiffness value of the virtual spring in the rotation direction with the depth direction as the axis, the stiffness value of the virtual spring in the rotation direction with the horizontal axis as the axis, and the rotation with the vertical direction as the axis The stiffness value of the virtual spring in the direction;

The stiffness value of the virtual spring in the rotation direction taking the vertical direction as the axis is smaller than the stiffness value of the virtual spring in the rotation direction taking the depth direction as the axis, and is smaller than the stiffness of the virtual spring in the rotation direction taking the transverse direction as the axis value;

The stiffness value of the virtual spring in the rotation direction with the vertical direction as the axis is less than or equal to the first rotation preset stiffness threshold;

The stiffness value of the virtual spring in the rotation direction with the depth direction as the axis and the stiffness value of the virtual spring in the rotation direction with the transverse axis as the axis are greater than or equal to the second rotation preset stiffness threshold.

In one embodiment, the first translation preset stiffness threshold is 0N/m-500N/m;

The second translation preset stiffness threshold is 4000N/m-5000N/m;

The first rotational preset stiffness threshold is 0Nm/rad to 20Nm/rad;

The second rotational preset stiffness threshold is 200Nm/rad˜300Nm/rad.

In one embodiment, the damping values of the virtual spring in directions of multiple degrees of freedom are set.

In one embodiment, the target area includes: femoral front end osteotomy plane, femoral anterior oblique osteotomy plane, femoral posterior condyle osteotomy plane, femoral posterior oblique osteotomy plane, femoral distal end osteotomy plane and tibial osteotomy flat.

In order to achieve the above object, according to the second aspect of the present application, a system for defining the motion area of a robot is provided, the system includes:

The model building module is configured to establish a virtual spring stiffness-damping model according to the displacement offset between the initial position and the actual position of the actuator at the end of the mechanical arm of the robot in multiple degrees of freedom directions;

The stiffness setting module is configured to set the stiffness values of each of the virtual springs in directions of multiple degrees of freedom, so as to limit the movement of the actuator to a pre-planned target area.

In one embodiment, the direction in which the actuator cuts into the target area is marked as the depth direction, the direction within the target area and perpendicular to the depth direction is marked as the transverse direction, and the direction perpendicular to the target area is marked as the horizontal direction. The direction is recorded as the vertical direction;

The stiffness setting module is further configured to, in the direction of the translation degree of freedom, set the stiffness value of the virtual spring in the depth direction, the stiffness value of the virtual spring in the transverse direction, and the stiffness value of the virtual spring in the vertical direction ;

The stiffness value of the virtual spring in the transverse direction is greater than the stiffness value of the virtual spring in the vertical direction;

In one embodiment, the stiffness setting module is further configured to, in the direction of the rotational degree of freedom, set the stiffness value of the virtual spring in the rotation direction with the depth direction as the axis, and set the stiffness value of the virtual spring in the rotation direction with the transverse direction as the axis. The stiffness value of the virtual spring on and the stiffness value of the virtual spring in the rotation direction with the vertical direction as the axis;

In one embodiment, the stiffness setting module is further configured to set the first translation preset stiffness threshold to 0N/m-500N/m;

The second translation preset stiffness threshold is 4000N/m-5000N/m;

The first rotational preset stiffness threshold is 0Nm/rad to 20Nm/rad;

The second rotational preset stiffness threshold is 200Nm/rad˜300Nm/rad.

In one embodiment, the system for defining the motion region of the robot further includes a damping setting module configured to set damping values of the virtual spring in directions of multiple degrees of freedom.

In a third aspect, the present application also proposes an electronic device, including: at least one processor and at least one memory; the memory is used to store one or more program instructions; the processor is used to run one or more Program instructions for performing any of the methods described above.

In a fourth aspect, the present application also proposes a computer-readable storage medium, which contains one or more program instructions, and the one or more program instructions are used to execute the method described in any one of the above .

In the embodiment of this application, according to the displacement offset between the initial position and the actual position of the actuator at the end of the robotic arm of the robot in the direction of multiple degrees of freedom, a stiffness-damping model of the virtual spring is established; The stiffness value of each virtual spring in the degree direction is used to limit the movement of the actuator to the pre-planned target area. By setting the stiffness value of the spring for each degree of freedom, in the direction of the degree of freedom with a large stiffness value, the actuator is not easy to displace, and it is difficult for the doctor to push it, so that the actuator can be limited to the target area and avoid bringing harm to the patient. injury, greatly improving the safety of surgery.

Description of drawings

The accompanying drawings, which constitute a part of this application, are used to provide an understanding of the application and make other features, objects and advantages of the application more apparent. The drawings and descriptions of the schematic embodiments of the application are used to explain the application, and do not constitute an improper limitation to the application. In the attached picture:

FIG. 1 is a flow chart of a method for defining a robot motion area according to an embodiment of the present application;

2 is a schematic diagram of the principle of a stiffness-damping model of a virtual spring according to an embodiment of the present application;

Fig. 3 is a schematic diagram of directions of multiple degrees of freedom of an actuator according to an embodiment of the present application;

Fig. 4A is a schematic diagram of a comparison before and after osteotomy according to an embodiment of the present application;

Fig. 4B is a schematic diagram of a femur in a first direction according to an embodiment of the present application;

Fig. 4C is a schematic diagram of a femur in a second direction according to an embodiment of the present application;

Fig. 4D is a schematic diagram of the third direction of the femur according to an embodiment of the present application;

Fig. 4E is a schematic view of the fourth direction of the femur according to an embodiment of the present application;

Fig. 4F is a schematic diagram of the fifth direction of the femur according to an embodiment of the present application;

Fig. 4G is a schematic diagram of a tibia according to an embodiment of the present application;

FIG. 5 is a schematic structural diagram of a system for defining a robot motion area according to an embodiment of the present application;

Fig. 6 is a schematic structural diagram of a device for defining a movement area of a robot according to an embodiment of the present application.

Detailed ways

In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiment of the application will be clearly and completely described below in conjunction with the accompanying drawings in the embodiment of the application. Obviously, the described embodiment is only It is an embodiment of a part of the application, but not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by persons of ordinary skill in the art without creative efforts shall fall within the scope of protection of this application.

It should be noted that the terms "first" and "second" in the description and claims of the present application and the above drawings are used to distinguish similar objects, but not necessarily used to describe a specific sequence or sequence. It should be understood that the data so used may be interchanged under appropriate circumstances for the embodiments of the application described herein. Furthermore, the terms "comprising" and "having", as well as any variations thereof, are intended to cover a non-exclusive inclusion, for example, a process, method, system, product or device comprising a sequence of steps or elements is not necessarily limited to the expressly listed instead, may include other steps or elements not explicitly listed or inherent to the process, method, product or apparatus.

In this application, the terms "upper", "lower", "left", "right", "front", "rear", "top", "bottom", "inner", "outer", "middle", The orientations or positional relationships indicated by "vertical", "horizontal", "horizontal", and "longitudinal" are based on the orientations or positional relationships shown in the drawings. These terms are mainly used to better describe the present application and its embodiments, and are not used to limit that the indicated devices, elements or components must have a specific orientation, or be constructed and operated in a specific orientation.

Moreover, some of the above terms may be used to indicate other meanings besides orientation or positional relationship, for example, the term "upper" may also be used to indicate a certain attachment relationship or connection relationship in some cases. Those of ordinary skill in the art can understand the specific meanings of these terms in the present invention according to specific situations.

Furthermore, the terms "installed", "disposed", "provided", "connected", "connected", "socketed" are to be interpreted broadly. For example, it may be a fixed connection, a detachable connection, or an integral structure; it may be a mechanical connection or an electrical connection; it may be a direct connection or an indirect connection through an intermediary; internal connectivity. Those of ordinary skill in the art can understand the specific meanings of the above terms in the present invention according to specific situations.

It should be noted that, in the case of no conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and embodiments.

The method for defining the motion area of a robot in the present application can be applied to the method for defining the osteotomy plane of a robot for knee joint replacement, and can also be applied to the method for defining the motion area of a robot in other fields.

For the limiting method of the robot motion area of the present application, refer to the flow chart of a kind of robot motion area limitation method shown in accompanying drawing 1; This method comprises the following steps:

Step S102 , according to the displacement offsets between the initial position and the actual position of the actuator at the end of the mechanical arm of the robot in directions of multiple degrees of freedom, a stiffness-damping model of the virtual spring is established.

Among them, the stiffness-damping model of the virtual spring is also called Cartesian Impedance Control Mode (CICM). In damped control mode, the behavior of the robot is compliance-sensitive and reacts to external influences such as obstacles or process forces. Applying an external force can cause the robot to deviate from the planned orbital path.

The model is based on virtual springs and dampers that stretch as the difference between the current measurement and the specified position of the TCP (Tool Center Point). The characteristics of the spring are described by the stiffness value (stiffness), and the characteristics of the damper are described by the damping value (damping). These parameters can be set individually for each translation or rotation dimension.

If the measured robot position corresponds to the specified robot position, the virtual spring is relaxed. Since the robot's behavior is compliant at this point, external forces or motion commands cause deviations between the robot's position setpoint and actual value. This causes the virtual spring to deflect, producing a force according to Hooke's law. The resultant force F can be calculated according to Hooke's law, using a set spring stiffness C and deflection Δx: F=C·Δx.

See the schematic diagram of the principle of the stiffness-damping model of the virtual spring shown in accompanying drawing 2; wherein, 1 is the spring offset; 2 is the virtual spring; 3 is the actual position; 4 is the force; 5 is the position of the set point. The spring stiffness determines how much the robot succumbs to external forces and deviates from its planned path.

Step S104, setting the stiffness values of each virtual spring in multiple degrees of freedom directions, so as to limit the movement of the actuator to a pre-planned target area.

Specifically, when setting the spring stiffness in different degrees of freedom directions, you can use the function setStiffness(…)(type:double) to set.

Applied in knee joint replacement surgery, the above-mentioned target area may be a target plane, that is, an osteotomy plane. Specifically, the target area may include: multiple osteotomy planes at different positions on the femur and tibia.

Exemplarily, in any one osteotomy plane, in the direction perpendicular to the osteotomy plane, a relatively large stiffness value is set, and the stiffness value is greater than a predetermined threshold, so as to limit the actuator to move in the direction perpendicular to the osteotomy plane. Movement, thereby effectively avoiding the actuator from deviating from the osteotomy plane. Among them, the predetermined threshold can be set flexibly. When the doctor pushes the mechanical arm, if the actuator deviates in the direction perpendicular to the osteotomy plane, the mechanical arm will output the corresponding feedback force (resistance), and the doctor can feel If there is no resistance, you know that the actuator has shifted undesirably, and you don't push the arm harder.

In specific implementation, after the actuator is aligned with the current target area, start the actuator. At this time, the control robot enters the state of the virtual spring damping model. In this state, the entire mechanical arm can be regarded as an approximate virtual spring. When a force is applied in any direction, the virtual spring obeys Hooke's law. Exemplarily, especially in the direction perpendicular to the osteotomy plane, if the stiffness in this direction is large, the deflection of the actuator in this direction will be small, so that the actuator can be stably limited to the osteotomy plane. On the bone plane, and avoid the actuator beyond the osteotomy plane, especially it can effectively prevent the actuator from moving in the direction perpendicular to the osteotomy plane, so as to minimize the actuator beyond the target area and reduce the patient’s accidental injury.

For the convenience of description, referring to Fig. 3 , the cutting depth direction of the actuator is marked as the depth direction, represented by a symbol X. The direction in the region where the actuator is located and perpendicular to the cutting direction of the actuator is marked as the transverse direction, represented by the symbol Y. The direction perpendicular to the plane of the actuator is recorded as the vertical direction and is represented by the symbol Z.

The degrees of freedom include translation degrees of freedom and rotation degrees of freedom, which are described in two cases below.

For the translational degree of freedom, in one embodiment, when setting the stiffness values of the virtual springs in the direction of multiple degrees of freedom, in the direction of the translational degree of freedom, set the stiffness of the virtual spring in the depth direction The stiffness value, the stiffness value of the virtual spring in the lateral direction, and the stiffness value of the virtual spring in the vertical direction.

Specifically, the stiffness value of the virtual spring in the depth direction is equal to or smaller than the stiffness value of the virtual spring in the transverse direction; the stiffness value of the virtual spring in the transverse direction is greater than the stiffness value of the virtual spring in the vertical direction. Both the stiffness value of the virtual spring in the depth direction and the stiffness value of the virtual spring in the lateral direction are less than or equal to the first translation preset stiffness threshold.

Exemplarily, the value range of the first translation preset stiffness threshold may be 0N/m˜500N/m. Therefore, the range of the stiffness value of the virtual spring in the depth direction X and the range of the stiffness value of the virtual spring in the transverse direction Y can be limited within the range of 0 N/m to 500 N/m. Of course, it can also be set to other ranges of values according to actual conditions. The principle is that the stiffness should be set relatively small, because according to Hooke's law, when the force is constant, the smaller the stiffness, the greater the spring deformation. Therefore, setting the stiffness in the depth direction as small as possible can help the actuator to move in this direction and cut. In the transverse Y direction, the setting stiffness is also relatively small, which also helps the actuator move in this direction for cutting. Both the depth direction and the transverse direction are on the osteotomy plane, and the stiffness values of the actuator in these two directions are set relatively small, which is conducive to the cutting movement of the actuator.

For the vertical direction, the stiffness value of the virtual spring in the vertical direction is greater than or equal to the second translation preset stiffness threshold. The second translation preset stiffness threshold may be 4000N/m˜5000N/m. It can be seen from the above that the stiffness of the vertical direction Z of the target area is the largest, and the setting range is 4000N/m-5000N/m. Of course, it can also be set flexibly according to the actual situation. The principle is that it should be as large as possible. Because according to Hooke's law, when the force is constant, the greater the stiffness, the smaller the spring deformation. Therefore, setting the stiffness in the Z direction as large as possible can help to avoid the displacement of the blade in the Z direction, because if the displacement occurs in the Z direction, it will directly cause the actuator to deviate from the predetermined osteotomy plane, which is easy to bring harm to the patient. Injury is not allowed.

For the degree of freedom of rotation, in one embodiment, when setting the stiffness values of each of the virtual springs in the directions of multiple degrees of freedom, set the stiffness values of the virtual springs in the rotation direction with the depth direction X as the axis;

The stiffness value of the virtual spring in the direction of rotation with the transverse Y as the axis;

The stiffness value of the virtual spring in the rotation direction with the vertical direction Z as the axis.

Specifically, the stiffness value of the virtual spring in the rotation direction of the axis in the vertical direction Z is smaller than the stiffness value of the virtual spring in the rotation direction of the axis in the depth direction X, and is smaller than the stiffness value of the virtual spring in the rotation direction of the axis in the horizontal direction Y .

The stiffness value of the virtual spring in the rotation direction with the vertical direction Z as the axis is less than or equal to the first rotation preset stiffness threshold. Optionally, the preset stiffness threshold of the first rotation is 0Nm/rad to 20Nm/rad, so that the actuator can rotate in the current target area on the Z axis in the vertical direction,

The stiffness of the virtual spring in the rotation direction with the depth direction X as the axis and the stiffness of the virtual spring in the rotation direction with the horizontal Y as the axis are greater than or equal to the second preset rotation stiffness threshold.

Wherein, the second rotation preset stiffness threshold is 200Nm/rad to 300Nm/rad, which limits the displacement of the actuator rotating around the X axis in the depth direction and the Y axis in the lateral direction, and prevents the actuator from breaking away from the current target area. Ensure the safety of osteotomy.

In an optional specific implementation, the preset stiffness value of the virtual spring in the depth direction X and the preset stiffness value of the virtual spring in the lateral direction Y can be 0N/m, and the preset stiffness value of the virtual spring in the vertical direction Z is 0N/m. Let the stiffness value be 5000N/m, the stiffness value of the virtual spring in the rotation direction with the vertical direction Z as the axis can be 10Nm/rad, the stiffness value of the virtual spring in the rotation direction with the depth direction X as the axis, and the horizontal direction The stiffness values of the virtual springs in the rotation direction of the axis Y may all be 300 Nm/rad.

In one embodiment, the defining method further includes: setting damping values of the virtual spring in directions of multiple degrees of freedom. Among them, the spring damping determines how much the virtual spring oscillates after being offset from the center position. The damping value may range from 0.1 to 1.0, for example, 0.7.

Specifically, the following function is used to set the damping value:

setDamping(...) Spring damping(type:double) spring damping.

Oscillation coefficient for all degrees of freedom: 0.1 to 1.0; default value: 0.7.

In the Robotics API, the degrees of freedom of Cartesian damping control modes are given by the enumeration CartDOF (package com.kuka.roboticsAPI.geometricModel). The values of this enumeration can be used to describe individual degrees of freedom, or a combination of multiple degrees of freedom.

CartDOF.X Translational degrees of freedom in the X direction;

CartDOF.Y Translational degrees of freedom in the Y direction;

CartDOF.Z Translational degrees of freedom in the Z direction;

CartDOF.TRANSL A combination of translation degrees of freedom in the X, Y, and Z directions;

CartDOF.A degree of freedom of rotation around the Z axis;

CartDOF.B rotation degree of freedom around the Y axis;

CartDOF.C rotates degrees of freedom around the X axis;

CartDOF.ROT combination of rotational degrees of freedom for X, Y, and Z axes;

CartDOF.ALL All combinations of all Cartesian degrees of freedom;

In the direction of the translational degree of freedom, set the stiffness to the maximum allowable value (5000) in the Z-axis direction, and set the stiffness to a smaller value (0-500) in the X and Y directions. At the same time, in the direction of the rotational degree of freedom B, Set the stiffness to the maximum allowable value (300) on C, and set the stiffness to a smaller value (0 to 100) in the direction A of the rotational degree of freedom around the Z axis, which can limit the movement of the TCP point of the tool at the end of the manipulator to On the XOY plane, and can rotate in a small range on the XOY plane.

The corresponding code is as follows:

CartesianImpedanceControlModeimpedanceMode = newCartesianImpedanceControlMode();

impedanceMode.parametrize(CartDOF.A).setStiffness(10);

impedanceMode.parametrize(CartDOF.B).setStiffness(300);

impedanceMode.parametrize(CartDOF.C).setStiffness(300);

impedanceMode.parametrize(CartDOF.Z).setStiffness(5000);

impedanceMode.parametrize(CartDOF.X).setStiffness(0);

impedanceMode.parametrize(CartDOF.Y).setStiffness(0);

impedanceMode.parametrize(CartDOF.ALL).setDamping(1); For all combinations of all Cartesian degrees of freedom, set the spring damping to 1;

motioncontainer = lbr. moveAsync(positionHold(impedanceMode, -1, TimeUnit. SECONDS)).

In one embodiment, when applied in knee joint replacement surgery, the aforementioned target areas include: femoral anterior oblique osteotomy plane, femoral anterior oblique osteotomy plane, femoral posterior condyle osteotomy plane, femoral posterior oblique osteotomy plane, distal femoral End osteotomy plane and tibial osteotomy plane.

Refer to the schematic diagram of the comparison before and after osteotomy shown in Fig. 4A. Specifically, as shown in FIG. 4B , the area covered by dark gray is not the area to be osteotomized at the front end of the femur, and this area will be the osteotomy plane of the front end of the femur. Referring to Fig. 4C, the dark gray covered area is the femoral anterior oblique osteotomy area, and this area is the femoral anterior oblique osteotomy plane. Referring to shown in accompanying drawing 4D, the dark gray area is the posterior femoral condyle osteotomy area, which is the posterior femoral condyle osteotomy plane after this area is cut off. Referring to Figure 4E, the dark gray area is the posterior oblique femoral osteotomy plane after osteotomy. Referring to FIG. 4F , the dark gray area is the area of the distal femur to be osteotomized. After this area is cut off, it becomes the osteotomy plane of the distal femur. The light gray area is a schematic diagram of the saw blade. Referring to Fig. 4G, the dark gray area is the tibial plateau area, which is the tibial osteotomy plane after being cut off.

In order to determine the above-mentioned osteotomy plane, it is necessary to determine the type of the prosthesis before the operation, and determine the target area according to the type of the prosthesis. In the second aspect, the present application also proposes a method for preoperative planning, which specifically includes the following steps:

After the medical image of the knee joint is obtained, the medical image is segmented and three-dimensionally reconstructed to obtain a three-dimensional bone model of the knee joint;

Determine key bone parameters based on the three-dimensional bone model; determine the type and model of the three-dimensional bone prosthesis model based on the key bone parameters;

Specifically, after obtaining the three-dimensional bone model of each bone region, the key parameters of the bone can include key anatomical points of the bone, key axes of the bone, and bone size parameters, and the key anatomical points of the bone can be identified based on a deep learning algorithm, such as a neural network model, And mark the identified key anatomical points of the bone on the three-dimensional bone model.

Bone size can include left and right femur diameter, femur anteroposterior diameter, tibial left and right diameter and tibial anteroposterior diameter. The line connecting the medial and lateral borders of the tibia is determined, and the anteroposterior diameter of the tibia is determined according to the line connecting the anterior and posterior borders of the tibia.

The key axis of the bone is determined based on the key anatomical points of the bone, and the key angle of the bone is determined based on the key axis of the bone. However, based on the key axis of the bone and the key angle of the bone, it is helpful to determine the type and model of the three-dimensional bone prosthesis model. The three-dimensional skeletal prosthesis model of the knee joint generally includes a three-dimensional femoral prosthesis model, a three-dimensional tibial prosthesis model, and a spacer model connecting the three-dimensional tibial prosthesis model and the three-dimensional femoral prosthesis model.

The three-dimensional skeletal prosthesis model can be a prosthesis model for total knee replacement currently on the market. There are many types of three-dimensional bone prosthesis models, and each type of three-dimensional bone prosthesis model has multiple models. For example, the types of three-dimensional femoral prosthesis models include ATTUNE-PS, ATTUNE-CR, SIGMA-PS150, etc., and the models of ATTUNE-PS include 1, 2, 3, 3N, 4, 4N, 5, 5N, 6, 6N.

Exemplarily, the implementation of the system determining the prosthesis model through the interactive interface may include: setting the configuration items of each three-dimensional bone prosthesis model on the interface, for example, it may be a three-dimensional femoral prosthesis model configuration item, a three-dimensional tibial prosthesis model configuration item item and the configuration item of the 3D spacer model, when a certain configuration item is triggered (for example, the selected method triggers the configuration item), it can automatically match the corresponding prosthesis library, and then detect which phantom model in the prosthesis library is activated Trigger, the prosthesis that is triggered signals as a replacement prosthesis. For example, when the femoral prosthesis model configuration item is triggered, it can establish an association with the femoral prosthesis library, and then display the types and models of all the prosthesis models in the femoral prosthesis library on the interface, and then detect which type of femoral prosthesis model and which type of femoral prosthesis model under this type is triggered, so that the triggered femoral prosthesis model is selected as the femoral prosthesis model.

Implanting the selected three-dimensional bone prosthesis model into the three-dimensional bone model;

Adjusting the installation position and installation angle of the three-dimensional bone prosthesis model based on the key bone parameters and the type and model of the three-dimensional bone prosthesis model.

Specifically, in order to realize the three-dimensional visual display of the matching adjustment process and matching effect of the bone and the prosthesis. After obtaining the three-dimensional bone model after implanting the three-dimensional bone prosthesis model, the femoral prosthesis model can be determined based on the femoral valgus angle, femoral varus angle, femoral external rotation angle, femoral internal rotation angle, left and right femoral diameter, and femoral anteroposterior diameter Whether the 3D femur model has been installed and fitted.

Based on the tibial varus angle, femoral valgus angle, left and right tibial diameter, and tibial anteroposterior diameter, it can be determined whether the tibial prosthetic model has been installed and adapted to the three-dimensional tibial model.

In one embodiment, the three-dimensional bone model includes a three-dimensional femoral model, the three-dimensional bone prosthesis model includes a three-dimensional femoral prosthesis model, the key parameters of the bone include key parameters of the femur, and the key parameters of the femur include the mechanical axis of the femur , femoral condyle line, posterior condyle line, femur left and right diameter and femur anteroposterior diameter;

The step of adjusting the placement position and placement angle of the three-dimensional skeleton prosthesis model based on the key bone parameters and the type and model of the three-dimensional skeleton prosthesis model includes:

Adjust the placement position of the three-dimensional femoral prosthesis model based on the left-right diameter of the femur and the anterior-posterior diameter of the femur;

Adjusting the varus or valgus angle of the three-dimensional femoral prosthesis model so that the cross-section of the three-dimensional femoral prosthesis model is perpendicular to the mechanical axis of the femur;

Adjust the internal rotation angle or external rotation angle of the three-dimensional femoral prosthesis so that the posterior femoral condyle angle PCA (the included angle between the femoral condyle line and the posterior condyle line on the cross-section projection line) is within a preset range.

In this optional implementation manner, when the placement position of the femoral prosthesis model satisfies that the femoral prosthesis model can cover the left and right sides of the femur and the front and back of the femur, the installation position is appropriate.

Based on the current position of the femoral prosthesis model, the femoral valgus angle and femoral varus angle can be determined according to the relative angle between the central axis of the femoral prosthesis model in the upper and lower direction of the coronal plane and the femoral force line, and according to the transverse axis of the femoral prosthesis model The external rotation angle and internal rotation angle are determined by the relative angle to the condylar line; the femoral flexion angle is determined by the angle between the femoral mechanical axis and the central axis of the femoral prosthesis model in the sagittal front-posterior direction. By adjusting the above angles, it can be determined whether the installation angle of the three-dimensional femoral prosthesis model is appropriate. For example, when the varus/valgus angle is adjusted to 0°, and the PCA is adjusted to 3°, it can be determined as the correct installation angle of the femoral prosthesis model. Adjust the placement position and placement angle to a suitable position.

In one embodiment, the three-dimensional bone model also includes a three-dimensional tibial model, and the three-dimensional femoral prosthesis model also includes a three-dimensional tibial prosthesis model; the key bone parameters also include tibial key parameters, and the tibial key parameters include Tibial mechanical axis, tibial left-right diameter and tibial anterior-posterior diameter;

Adjust the placement position of the three-dimensional tibial prosthesis model based on the tibial left-right diameter and tibial-posterior diameter;

The varus angle or valgus angle of the three-dimensional tibial prosthesis is adjusted so that the tibial mechanical axis is perpendicular to the cross-section of the three-dimensional tibial prosthesis.

In one embodiment, after the step of adjusting the placement position and placement angle of the three-dimensional skeletal prosthesis model, the method further includes:

Based on the matching relationship between the three-dimensional bone prosthesis model and the three-dimensional prosthesis model, the osteotomy is simulated, and the three-dimensional bone postoperative simulation model is obtained;

Carry out motion simulation including straight position and flexion position to described three-dimensional femoral postoperative simulation model;

The extension gap is determined in the state of extension, and the flexion gap is determined in the flexion state;

Comparing the straightening gap and the flexion gap, the compatibility of the three-dimensional bone prosthesis model is verified.

In this optional implementation, the bone osteotomy thickness is determined according to the bone prosthesis model design principle, and different bone prosthesis models may correspond to different osteotomy thicknesses; the osteotomy thickness, bone prosthesis model Once matched to the bone, the bone's osteotomy plane can be determined.

After adjusting the placement position and placement angle of the three-dimensional bone prosthesis model, simulate the osteotomy based on the matching relationship between the three-dimensional bone prosthesis model and the three-dimensional bone model, and obtain the three-dimensional bone postoperative simulation model.

After obtaining the three-dimensional skeletal postoperative simulation model, the motion simulation can be performed, and the extension gap and flexion gap can be determined through the extension position simulation map and the flexion position simulation map. Based on the straightening gap and the flexion gap, it is determined whether the three-dimensional bone prosthesis model fits the osteotomized three-dimensional bone model. By simulating the installation effect of the prosthesis, it can be observed from different angles whether the size and position of the prosthesis are appropriate, whether there is collision or misplacement of the prosthesis, and then it is possible to accurately determine whether the prosthesis and the bone fit. The user can determine whether the bone prosthesis model needs to be adjusted through the final simulation image. If the type and model of the bone prosthesis are changed, the prosthesis library can be called again to generate a three-dimensional replacement based on the new bone prosthesis model. Skeletal postoperative simulation model. By simulating the expected postoperative effect, the resulting bone prosthesis model can be more closely matched to the patient's knee joint.

In this embodiment, through the postoperative simulation of the bone model with the prosthesis model installed, the gap can be accurately determined, thereby overcoming the reliance on the technique and experience of the surgeon in the related art, and completely relying on the gap balance and the installation of the prosthesis position. The subjective feeling is assessed, which in turn leads to the defect of low surgical precision.

In one embodiment, the preoperative planning method further includes: determining the three-dimensional coordinates of the center point of the femoral medullary cavity based on the three-dimensional femoral model; creating an intramedullary positioning analog rod by a circular fitting method; using the intramedullary positioning analog rod Determine the opening point of the femur.

In an optional implementation, in knee arthroplasty, it is also necessary to determine the position of the needle entry point of the femoral intramedullary positioning analog rod, wherein the apex of the intercondylar fossa can be used as the position of the needle entry point of the intramedullary positioning analog rod. The position of the point can be used as the opening point of the femur. During the operation, the intramedullary locating analog rod and the opening point of the femur are visualized on the three-dimensional bone model to guide the doctor to open the pulp.

Before the osteotomy, in order to ensure that the position of the surgical robot matches the position of the patient's knee joint, the bones need to be registered. In the third aspect, this application also proposes a bone registration method, which specifically includes the following step:

Obtain the spatial position of the preoperative planning point on the bone in the 3D model of the knee joint in the coordinates of the 3D model, and the spatial position of the intraoperative marker point on the solid knee joint bone in the world coordinate system;

Roughly registering the spatial position of the preoperative planning point in the three-dimensional coordinate system and the spatial position of the intraoperative marker point in the world coordinate system to obtain a coarse registration matrix;

Obtain the spatial position of the lined point set on the target bone of the knee joint of the entity in the world coordinate system; compare the spatial position of the lined point set in the world coordinate system with the three-dimensional model according to the coarse registration matrix Perform fine registration to register the world coordinate system to the 3D model coordinate system.

Specifically, the three-dimensional model refers to the bone model of the knee joint. The preoperative planning points are points planned in advance in the three-dimensional model for registration. Intraoperative marker points are the points marked on the bone surface by the doctor during the operation.

Before surgery, preoperative planning points are determined on the bones in a 3D model of the knee joint. The three-dimensional model may specifically include a three-dimensional femur model and a three-dimensional tibial model. During knee replacement surgery, with the patient in the supine position, doctors place pins and trackers on each bone in the patient's knee. Then take the medial approach of the knee joint, cut the skin and subcutaneous tissue, enter the joint to fully expose the tibial plateau, and register and register the bones of the knee joint in turn.

During the bone registration process, the optical navigation and positioning system obtains the spatial position of the preoperative planning points on the bones in the 3D model of the knee joint in the coordinate system of the 3D model, and the intraoperative marker points on each bone of the knee joint in the world. The spatial position in the coordinate system. For example, 40 bone positioning points can be collected as intraoperative marker points.

The registration process of the 3D model can be divided into two stages: the coarse registration stage and the fine registration stage. In the rough registration stage, the preset 3D space point cloud search method can be used for rough registration.

For the coarse registration, in one embodiment, the rough registration of the spatial position of the preoperative planning point in the three-dimensional coordinate system and the spatial position of the intraoperative marker point in the world coordinate system includes:

Through the preset three-dimensional space point cloud search method, the spatial position of the preoperative planning point in the three-dimensional coordinate system and the spatial position of the intraoperative marker point in the world coordinate system are respectively triangulated to obtain the intraoperative marker The actual operation triangle sequence corresponding to the point and the planning triangle sequence corresponding to the preoperative planning point;

Correcting the preoperative planning points according to the planning triangle sequence by preset three-dimensional space point cloud search method to obtain the corrected preoperative planning points;

The intraoperative marker points corresponding to the practical operation triangle sequence are roughly registered with the corrected preoperative planning points.

In one embodiment, the preset three-dimensional space point cloud search method is used to respectively analyze the spatial position of the preoperative planning point in the three-dimensional coordinate system and the spatial position of the intraoperative marker point in the world coordinate system Perform triangulation processing to obtain the practical triangle sequence corresponding to the intraoperative marker points and the planning triangle sequence corresponding to the preoperative planning points, including:

By preset three-dimensional space point cloud search method, according to the spatial position of the preoperative planning point in the three-dimensional coordinate system, the first three points of the preoperative planning point are formed into a triangle, and according to the intraoperative marker point in the world coordinate system The spatial position below will form a triangle with the first three points of the intraoperative marker points;

Starting from the fourth point, select two points from the previous points to form a triangle with the current point, and obtain the practical triangle sequence corresponding to the marked point in the operation and the planning triangle sequence corresponding to the preoperative planning point; the practical operation The triangular sequence is the same as the triangular composition order of the planned triangular sequence.

In one embodiment, the pre-operative planning points are corrected according to the planning triangle sequence through the preset three-dimensional space point cloud search method, and the corrected pre-operative planning points obtained include:

Determine the second neighborhood space point set of the preoperative planning point on the 3D model by preset 3D space point cloud search method;

Screening out a second target point from the set of points in the second neighborhood space;

The spatial position of the preoperative planning point under the three-dimensional model coordinates is corrected to the position corresponding to the second target point according to the planning triangle sequence.

After the rough registration is completed, the second stage of fine registration is required. In the stage of fine registration, no preoperative planning is required. During the operation, surgical probes and other surface calibration equipment can be used to draw lines on the bone surfaces of the solid knee joint, and the lines drawn on each bone surface can be collected through the line drawing operation. Line point set. Wherein, the scribing area where the scribing operation needs to be performed is the key bone area on the surface of each bone, that is, the area containing the key bone points.

Specifically, the dashed point set is composed of points on multiple line segments, for example, may include points in three line segments. The points in the set of dashed points are paired in triangles, and a point is selected in each line segment, and every three points form a triangle. The principle of composition is that the perimeter of the triangle is the largest. According to the triangle pairing method, a sequence of paired triangles is obtained. The sequence of paired triangles includes a plurality of triangles.

Exemplarily, the position of the tracker on the surgical probe is tracked by the tracking camera in the optical navigation and positioning system, and the probe tracker on the surgical probe acquired by the tracking camera is in the world coordinates during the scribing process. Determine the spatial position of the lined point set on each bone of the knee joint of the entity under the world coordinates, so as to obtain the lined point set.

In an optional manner of this embodiment, during the line marking operation, the surgical probe may be used to perform sampling at a frequency S, and the point collection operation may be performed on the line to subdivide the entire line segment into several point sets.

In the fine registration process, the neighborhood space point set of the dashed point set on the 3D model can be determined first, and then the dashed point set can be aligned according to the neighborhood space point set and the spatial position of the dashed point set in the world coordinate system. The spatial position in the three-dimensional model coordinate system is corrected, and then the corrected line point set is registered with the space position of the line point set in the world coordinate system.

In one embodiment, the fine registration of the spatial position of the line point set in the world coordinate system with the 3D model according to the coarse registration matrix includes:

Reflecting the spatial position of the dashed point set in the world coordinate system back into the three-dimensional model coordinate system according to the coarse registration matrix, to obtain the position of the dashed point set in the three-dimensional model coordinate system;

Performing a neighborhood space search on the three-dimensional model according to the position of the dashed point set in the three-dimensional model coordinate system, to obtain a first neighborhood space point set;

Correcting the spatial position of the dashed point set in the world coordinate system according to the first neighborhood space point set to obtain a line segment point set; finely registering the line segment point set with the 3D model.

Specifically, the coarse registration matrix represents the conversion relationship between the world coordinate system and the three-dimensional model coordinate system obtained by the coarse registration. According to the coarse registration matrix, the spatial position of the dashed point set in the world coordinate system can be reflected back to the 3D model coordinate system, so as to obtain the position of the dashed point set in the 3D model coordinate system. Since the 3D model corresponds to the 3D model coordinate system, the neighborhood space search can be performed on the 3D model according to the position of the dashed point set in the 3D model coordinate system to obtain the first neighborhood space point set. The first neighborhood space point set is a neighborhood space point set corresponding to the dashed line point set in the three-dimensional model coordinate system.

In an implementation manner, the correcting the spatial position of the lined point set in the world coordinate system according to the first neighborhood spatial point set includes:

performing triangle pairing on the points in the dashed point set to obtain a paired triangle sequence; correcting the points in the dashed point set according to the first neighborhood space point set and the paired triangle sequence;

This step specifically includes: screening out a first target point from the point set in the first neighborhood space; correcting the positions of the points in the lined point set to the positions corresponding to the first target point according to the paired triangle sequence.

The first neighborhood space point set includes a large number of points. The paired triangle sequence includes multiple triangles, and each triangle includes three triangle points. For the current triangle, the target point corresponding to each triangle point of the current triangle can be screened in the second neighborhood space point set according to the paired triangle sequence to obtain the first A set of target points. The default screening strategy is that the triangle formed by the screened three target points is congruent with the triangle in the paired triangle sequence. Since the error of congruent triangles is extremely small, the spatial positions of the three triangle points of the current triangle under the coordinates of the three-dimensional model can be respectively corrected to the positions corresponding to the target points in the first target point set, and the correction process can be repeated to achieve A large number of triangles continuously correct the spatial position of the dashed point set in the 3D model coordinates, making the spatial position of the dashed point set reflected in the 3D model coordinate system more accurate.

Afterwards, the corrected set of dashed points and the spatial position of the set of dashed points in the world coordinate system are registered through a registration algorithm to obtain a registration result. For example, the registration algorithm may be ICP (Iterative Closest Point, iterative closest point algorithm). The registration result can be the transformation relationship between the final world coordinate system and the three-dimensional coordinates, and the accuracy of the intraoperative operation can be improved through the registration result.

In this embodiment, the spatial position of the lined point set on each bone of the knee joint of the entity in the world coordinate system is acquired through the line line operation, so that the line point set is placed in the world coordinate system according to the rough registration matrix The spatial position below is precisely registered with the 3D model. Compared with the traditional point-taking registration algorithm, the registration efficiency is greatly improved, and the registration accuracy is also greatly improved.

Corresponding to the above-mentioned method for defining the robot movement area in the first aspect, in the fourth aspect, the present application also proposes a method for controlling the mechanical arm of a surgical robot, including the following steps:

During the operation of the actuator at the end of the mechanical arm, the offset of the actuator relative to the current target area is determined according to the current spatial position of the actuator and the spatial position of the current target area of the knee joint;

Based on the offset, the robotic arm is controlled to confine the movement of the actuator within the target area.

Specifically, the surgical robot may be a joint replacement robot (including, but not limited to, a total knee replacement robot and other robots that require osteotomy), and the robot may mainly include a mechanical arm, and (in a detachable manner) an executive arm installed at the end of the robot. device, the actuator may be an osteotomy saw blade. The main control system of the upper computer can send an osteotomy start signal to the robotic arm, and the robotic arm drives the osteotomy saw at the end to move after receiving the signal.

The end of the robotic arm and the actual area to be osteotomized (for example, the femoral area of the knee joint, the tibial area) can be pre-set with a tracer. The tracer includes a light-sensitive ball that can emit infrared rays and is tracked in real time by a binocular infrared camera. The position of the light-sensitive ball at the end of the manipulator, the position of the light-sensitive ball on the femoral area, and the position of the light-sensitive ball on the tibial area can determine the current spatial position of the actuator at the end of the manipulator, and the position of each target area. The current spatial position, so that the spatial position of the actuator and the spatial position of the current target area can be determined in real time, and the offset of the actuator relative to the current target area can be determined based on the spatial position of the actuator and the spatial position of the current target area.

A pre-planned osteotomy sequence is displayed in the three-dimensional model, and the current target area is a target area selected from a plurality of target areas in response to the operator.

As an optional implementation of this embodiment, before the actuator runs, when the robotic arm is operated to the knee joint, according to the spatial position of the current target area of the knee joint planned in the three-dimensional model coordinate system, the position of the actuator The current spatial position determines the position difference between the current spatial position of the target area and the current spatial position of the actuator; determines the displacement of the manipulator according to the position difference; displays in the three-dimensional model the corresponding displacement The instruction adjustment information of the instruction is used to enable the operator to operate the robotic arm according to the instruction adjustment information, so as to adjust the actuator so that its plane is coplanar with the current target area. It can be understood that the plane of the actuator is coplanar with the target area, which means that the actuator is on the outer edge of the current target area, and the plane of the actuator and the current target area are roughly aligned in the same plane.

The indication adjustment information corresponding to the displacement amount may include the adjustment path corresponding to the displacement amount enlarged and displayed in the target area, guiding the doctor to hold the mechanical arm and adjust the plane of the actuator to align with the osteotomy plane (the actuator is on the osteotomy plane , the actuator is approximately coplanar with the osteotomy plane).

In one embodiment, the step of controlling the robotic arm to limit the movement of the actuator within the target area according to the offset includes:

When the actuator is running, the Cartesian damping control mode modeled on the virtual spring and damper is started, and the manipulator is based on the preset stiffness value C of each virtual spring in the aforementioned multiple degrees of freedom directions and in multiple degrees of freedom directions The offset Δx, output the feedback force F opposite to the operated direction, F=Δx*C, so as to limit the movement of the actuator within the current target area.

The magnitudes of the preset stiffness values C in the directions of each degree of freedom are as described above, and will not be repeated here.

In the sixth aspect, the present application also provides a system for limiting the motion plane of a robot, refer to the schematic structural diagram of a system for limiting the motion plane of a robot shown in Figure 5; the system includes:

The model establishment module 61 is configured to establish a virtual spring stiffness-damping model according to the displacement offset between the initial position and the actual position of the actuator at the end of the mechanical arm of the robot in multiple degrees of freedom directions;

The stiffness setting module 62 is configured to set stiffness values of each of the virtual springs in directions of multiple degrees of freedom, so as to limit the movement of the actuator to a pre-planned target area. In one embodiment, the direction in which the actuator cuts into the target area is marked as the depth direction, the direction within the target area and perpendicular to the depth direction is marked as the transverse direction, and the direction perpendicular to the target area is marked as the horizontal direction. The direction is recorded as the vertical direction;

The stiffness setting module 62 is further configured to, in the direction of the translation degree of freedom, set the stiffness value of the virtual spring in the depth direction, the stiffness value of the virtual spring in the transverse direction, and the stiffness value of the virtual spring in the vertical direction;

In one embodiment, the stiffness setting module 62 is further configured to, in the direction of the rotational degree of freedom, set the stiffness value of the virtual spring in the rotation direction with the depth direction as the axis, and set the stiffness value of the virtual spring in the rotation direction with the transverse direction as the axis. The stiffness value of the virtual spring in the direction and the stiffness value of the virtual spring in the rotation direction with the vertical direction as the axis;

In one embodiment, the stiffness setting module 62 is further configured to set the first translation preset stiffness threshold to 0N/m-500N/m, and the second translation preset stiffness threshold to 4000N/m-5000N/m , the first rotation preset stiffness threshold is 0N/m˜20N/m, and the second rotation preset stiffness threshold is 200N/m˜300N/m.

In one embodiment, a damping setting module 63 is further included, configured to set damping values of the virtual spring in directions of multiple degrees of freedom.

The model building module 61 , the stiffness setting module 62 and the damping setting module 63 can all be located in the robotic arm subsystem 12 .

In the sixth aspect, the present application also proposes a device for defining a robot motion plane, refer to the schematic structural diagram of a device for defining a robot motion plane shown in FIG. 6 ; the device includes: at least one processor 71 and at least one memory 72; The memory 72 is used to store one or more program instructions; the processor 71 is used to run one or more program instructions to perform any of the steps described above.

In the seventh aspect, the present application also proposes a computer-readable storage medium, which contains one or more program instructions, and the one or more program instructions are used to perform the steps described in any one of the above .

Various methods, steps, and logic block diagrams disclosed in the embodiments of the present application may be implemented or executed. A general-purpose processor may be a microprocessor, or the processor may be any conventional processor, or the like. The steps of the method disclosed in connection with the embodiments of the present application may be directly implemented by a hardware decoding processor, or implemented by a combination of hardware and software modules in the decoding processor. The software module can be located in a mature storage medium in the field such as random access memory, flash memory, read-only memory, programmable read-only memory or electrically erasable programmable memory, register. The processor reads the information in the storage medium, and completes the steps of the above method in combination with its hardware.

A storage medium may be a memory, which may be, for example, volatile memory or nonvolatile memory, or may include both volatile and nonvolatile memory.

Among them, the non-volatile memory can be read-only memory (Read-Only Memory, referred to as ROM), programmable read-only memory (Programmable ROM, referred to as PROM), erasable programmable read-only memory (Erasable PROM, referred to as EPROM) , Electrically Erasable Programmable Read-Only Memory (Electrically Erasable EPROM, referred to as EEPROM) or flash memory.

The volatile memory may be Random Access Memory (RAM for short), which acts as an external cache. By way of illustration and not limitation, many forms of RAM are available, such as Static Random Access Memory (Static RAM, SRAM for short), Dynamic Random Access Memory (Dynamic RAM, DRAM for short), Synchronous Dynamic Random Access Memory (Synchronous DRAM, referred to as SDRAM), double data rate synchronous dynamic random access memory (Double Data Rate SDRAM, referred to as DDRSDRAM), enhanced synchronous dynamic random access memory (Enhanced SDRAM, referred to as ESDRAM), synchronous connection dynamic random access memory (Synchlink DRAM, referred to as SLDRAM) and direct memory bus random access memory (DirectRambus RAM, referred to as DRRAM).

The storage medium described in the embodiments of the present application is intended to include but not limited to these and any other suitable types of storage.

Obviously, those skilled in the art should understand that each module or each step of the above-mentioned application can be realized by a general-purpose computing device, and they can be concentrated on a single computing device, or distributed in a network composed of multiple computing devices Optionally, they can be implemented with program codes executable by a computing device, so that they can be stored in a storage device and executed by a computing device, or they can be made into individual integrated circuit modules, or they can be integrated into Multiple modules or steps are fabricated into a single integrated circuit module to realize. As such, the present application is not limited to any specific combination of hardware and software.

The above descriptions are only preferred embodiments of the present application, and are not intended to limit the present application. For those skilled in the art, there may be various modifications and changes in the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of this application shall be included within the protection scope of this application.

Claims

A method for limiting the movement area of a robot, comprising:

According to the displacement offset between the initial position and the actual position of the actuator at the end of the robotic arm of the robot in multiple degrees of freedom directions, the stiffness-damping model of the virtual spring is established;

Stiffness values of each of the virtual springs in directions of multiple degrees of freedom are set to limit the movement of the actuator to a pre-planned target area.
The method for defining the movement area of a robot according to claim 1, wherein the direction in which the actuator cuts into the target area is marked as the depth direction, and the direction within the target area and perpendicular to the depth direction is marked as Horizontally, the direction perpendicular to the target area is recorded as the vertical direction;

Set the stiffness values of each of the virtual springs in directions of multiple degrees of freedom, including:

In the translation degree of freedom direction, set the stiffness value of the virtual spring in the depth direction, the stiffness value of the virtual spring in the lateral direction, and the stiffness value of the virtual spring in the vertical direction;

The stiffness value of the virtual spring in the depth direction is equal to or smaller than the stiffness value of the virtual spring in the transverse direction;

The stiffness value of the virtual spring in the transverse direction is smaller than the stiffness value of the virtual spring in the vertical direction;

The stiffness value of the virtual spring in the depth direction and the stiffness value of the virtual spring in the transverse direction are both less than or equal to the first translation preset stiffness threshold, and the stiffness value of the virtual spring in the vertical direction is greater than or equal to the second Shift the preset stiffness threshold.
The method for defining the motion region of a robot according to claim 2, wherein setting the stiffness values of each of the virtual springs in directions of multiple degrees of freedom includes:

In the direction of the degree of freedom of rotation, set the stiffness value of the virtual spring in the rotation direction with the depth direction as the axis, the stiffness value of the virtual spring in the rotation direction with the horizontal axis as the axis, and the rotation with the vertical direction as the axis The stiffness value of the virtual spring in the direction;

The stiffness value of the virtual spring in the rotation direction taking the vertical direction as the axis is smaller than the stiffness value of the virtual spring in the rotation direction taking the depth direction as the axis, and is smaller than the stiffness of the virtual spring in the rotation direction taking the transverse direction as the axis value;

The stiffness value of the virtual spring in the rotation direction with the vertical direction as the axis is less than or equal to the first rotation preset stiffness threshold;

The stiffness value of the virtual spring in the rotation direction with the depth direction as the axis and the stiffness value of the virtual spring in the rotation direction with the transverse axis as the axis are greater than or equal to the second rotation preset stiffness threshold.
The limiting method of the robot motion area according to claim 3, wherein,

The first translation preset stiffness threshold is 0N/m-500N/m;

The second translation preset stiffness threshold is 4000N/m-5000N/m;

The first rotational preset stiffness threshold is 0Nm/rad to 20Nm/rad;

The second rotational preset stiffness threshold is 200Nm/rad˜300Nm/rad.
The method for defining the motion area of a robot according to claim 1, further comprising: setting damping values of the virtual spring in directions of multiple degrees of freedom.
The limiting method of the robot motion area according to claim 1, wherein,

The target area includes: the osteotomy plane of the front end of the femur, the osteotomy plane of the anterior oblique femur, the osteotomy plane of the posterior femoral condyle, the osteotomy plane of the posterior oblique femur, the osteotomy plane of the distal femur and the osteotomy plane of the tibia.
A system for limiting the movement area of a robot, comprising:

The model building module is configured to establish a virtual spring stiffness-damping model according to the displacement offset between the initial position and the actual position of the actuator at the end of the mechanical arm of the robot in multiple degrees of freedom directions;

The stiffness setting module is configured to set the stiffness values of each of the virtual springs in directions of multiple degrees of freedom, so as to limit the movement of the actuator to a pre-planned target area.
The system for limiting the movement area of a robot according to claim 7, wherein the direction in which the actuator cuts into the target area is marked as the depth direction, and the direction within the target area and perpendicular to the depth direction is marked as Horizontally, the direction perpendicular to the target area is recorded as the vertical direction;

The stiffness setting module is further configured to, in the direction of the translation degree of freedom, set the stiffness value of the virtual spring in the depth direction, the stiffness value of the virtual spring in the transverse direction, and the stiffness value of the virtual spring in the vertical direction ;

The stiffness value of the virtual spring in the depth direction is equal to or smaller than the stiffness value of the virtual spring in the transverse direction;

The stiffness value of the virtual spring in the transverse direction is greater than the stiffness value of the virtual spring in the vertical direction;

The stiffness value of the virtual spring in the depth direction and the stiffness value of the virtual spring in the transverse direction are both less than or equal to the first translation preset stiffness threshold, and the stiffness value of the virtual spring in the vertical direction is greater than or equal to the second Shift the preset stiffness threshold.
An electronic device, comprising: at least one processor and at least one memory; the memory is used to store one or more program instructions; the processor is used to run one or more program instructions to perform the The method described in any one of 1-6.
A computer-readable storage medium, the computer-readable storage medium contains one or more program instructions, and the one or more program instructions are used to execute the method according to any one of claims 1-6.