CN113842217B - Method and system for limiting motion area of robot - Google Patents

Abstract

The application discloses a method and a system for limiting a motion area of a robot. The method comprises the following steps: establishing a stiffness-damping model of a virtual spring according to displacement offsets of an actuator at the tail end of a mechanical arm of the robot in the directions of multiple degrees of freedom from an actual position; setting stiffness values of each of the virtual springs in a plurality of degrees of freedom to define movement of the actuator over a pre-planned target area. The method adopts a virtual spring stiffness-damping model, sets the stiffness in each degree of freedom direction, and can limit the movement in each degree of freedom direction, when external force acts on each degree of freedom, the displacement is very small in the direction of the degree of freedom with high stiffness, and even the displacement can not be generated, so that the actuator can be limited on a target area, and the actuator is prevented from deviating from the target area to cause injury to a patient.

Description

Method and system for limiting motion area of robot

technical field

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

Background technique

In the existing surgery, when a robot is used for assistance, the doctor's hand supports the robotic arm of the robot to operate. During the operation, due to the negligence of the operation, the active or passive force may be too strong in the place where the force should not be applied, so that the saw blade at the end of the robot arm exceeds the predetermined operation area, thus causing unnecessary unnecessary damage to the patient. harm.

SUMMARY OF THE INVENTION

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

In order to achieve the above object, according to one aspect of the present application, a method for defining a 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 manipulator arm of the robot in the directions of multiple degrees of freedom, the stiffness-damping model of the virtual spring is established;

The stiffness values of each of the virtual springs in a plurality of degrees of freedom directions are set to confine the movement of the actuator to a pre-planned target area.

In an embodiment, the direction in which the actuator cuts into the target area is denoted as the depth direction, the direction in the target area and perpendicular to the depth direction is denoted as the lateral direction, and the direction perpendicular to the target area is denoted as the horizontal direction vertical direction;

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

In the direction of 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 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 lateral direction;

The stiffness value of the virtual spring in the lateral 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 lateral 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 Translate the preset stiffness threshold.

In one embodiment, the stiffness values of each of the virtual springs in the directions of multiple degrees of freedom are set, including:

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, the stiffness value of the virtual spring in the rotation direction with the lateral axis as the axis, and set the stiffness value of the virtual spring in the vertical direction as the axis stiffness value of the virtual spring in the direction;

The stiffness value of the virtual spring in the rotational direction of the axis is smaller than the stiffness value of the virtual spring in the rotational direction of the axis, and is smaller than the stiffness of the virtual spring in the rotational direction of 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 rotational direction of the axis with the depth direction as the axis and the stiffness value of the virtual spring in the rotational direction of the axis with the lateral direction are greater than or equal to the second rotational preset stiffness threshold.

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

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

The first rotation preset stiffness threshold is 0Nm/rad～20Nm/rad;

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

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

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

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

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

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

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

The stiffness setting module is further configured to, in the direction of the translational degree of freedom, 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 lateral direction;

The stiffness value of the virtual spring in the lateral 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 lateral 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 Translate the preset stiffness threshold.

In an 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 with the depth direction as the axis of rotation, and the transverse direction as the axis of rotation. The stiffness value of the virtual spring and the stiffness value of the virtual spring in the rotation direction of the axis with the vertical direction;

The stiffness value of the virtual spring in the rotational direction of the axis is smaller than the stiffness value of the virtual spring in the rotational direction of the axis, and is smaller than the stiffness of the virtual spring in the rotational direction of 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 rotational direction of the axis with the depth direction as the axis and the stiffness value of the virtual spring in the rotational direction of the axis with the lateral direction are greater than or equal to the second rotational preset stiffness threshold.

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

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

The first rotation preset stiffness threshold is 0Nm/rad～20Nm/rad;

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

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

In a third aspect, the present application also provides 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 for executing any of the methods described above.

In a fourth aspect, the present application also provides a computer-readable storage medium, where the computer-readable storage medium 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 the present application, the stiffness-damping model of the virtual spring is established 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 the directions of multiple degrees of freedom; The stiffness value of each of the virtual springs in the degree direction is used to limit the movement of the actuator to a 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 easily displaced, and it is difficult for the doctor to push, so that the actuator can be limited to the target area to avoid causing 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 a further understanding of the application and make other features, objects and advantages of the application more apparent. The accompanying drawings and descriptions of the exemplary embodiments of the present application are used to explain the present application, and do not constitute an improper limitation of the present application. In the attached image:

1 is a flowchart of a method for defining a motion area of a robot according to an embodiment of the present application;

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

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

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

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

4C is a schematic diagram of a second orientation of the femur according to an embodiment of the present application;

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

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

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

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

5 is a schematic structural diagram of a system for defining a motion area of a robot 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 make those skilled in the art better understand the solutions of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only The embodiments are part of the present application, but not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the scope of protection of the present application.

It should be noted that the terms "first", "second", etc. in the description and claims of the present application and the above drawings are used to distinguish similar objects, and are not necessarily used to describe a specific sequence or sequence. It is to be understood that the data so used are interchangeable under appropriate circumstances for the embodiments of the application described herein. Furthermore, the terms "comprising" and "having" and any variations thereof, are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those expressly listed Rather, those steps or units may include other steps or units not expressly listed or inherent to these processes, methods, products or devices.

In this application, the terms "upper", "lower", "left", "right", "front", "rear", "top", "bottom", "inner", "outer", "middle", The orientation or positional relationship indicated by "vertical", "horizontal", "horizontal", "longitudinal", etc. is based on the orientation or positional relationship shown in the drawings. These terms are primarily used to better describe the invention and its embodiments, and are not intended to limit the fact that the indicated device, element or component must have a particular orientation, or be constructed and operated in a particular orientation.

In addition, some of the above-mentioned terms may be used to express other meanings besides orientation or positional relationship. For example, the term "on" may also be used to express a certain attachment or connection relationship in some cases. For those of ordinary skill in the art, the specific meanings of these terms in the present invention can be understood according to specific situations.

Furthermore, the terms "installed", "set up", "provided with", "connected", "connected", "socketed" should be construed broadly. For example, it may be a fixed connection, a detachable connection, or a unitary structure; it may be a mechanical connection, or an electrical connection; it may be directly connected, or indirectly connected through an intermediary, or between two devices, elements, or components. internal communication. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

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

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

For the method for limiting the motion area of a robot of the present application, refer to the flowchart of a method for limiting the motion area of a robot shown in FIG. 1 ; the method includes the following steps:

In step S102, a stiffness-damping model of the virtual spring is established 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 the directions of multiple degrees of freedom.

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

This model is implemented based on virtual springs and dampers that stretch as the difference between the current measurement and the specified position of the TCP (Tool CenterPoint). The properties of the spring are described by the stiffness value (stiffness), and the properties of the damper are described by the damping value (damping). Each of these parameters can be set individually in 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 time, external forces or motion commands cause deviations between the robot's position set point and the actual value. This causes the virtual spring to deflect, producing a force in accordance with Hooke's law. The resultant force F can be calculated according to Hooke's law, using the set spring stiffness C and offset Δx: F=C·Δx.

Refer to the schematic diagram of the stiffness-damping model of the virtual spring shown in FIG. 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 stiffness values of the virtual springs in the directions of multiple degrees of freedom, so as to limit the motion 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 it.

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

Exemplarily, in any 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 in the direction perpendicular to the osteotomy plane. movement, so as to effectively avoid the actuator from deviating from the osteotomy plane. Among them, the predetermined threshold can be flexibly set. When the doctor pushes the robotic arm, if the actuator is offset in the direction perpendicular to the osteotomy plane, the robotic arm will output a corresponding feedback force (resistance), and the doctor can feel it. resistance, you will know that the actuator has an undesired deflection, and will not push the robotic arm too hard.

In the specific implementation, after the actuator is aligned with the current target area, the actuator is started. At this time, the control robot enters the state of the virtual spring damping model. In this state, the entire robotic 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 cutting plane. On the bone plane, and avoid the actuator from exceeding 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 from exceeding the target area and reduce the risk to the patient. wrong injury.

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

The degrees of freedom include translational degrees of freedom and rotational degrees of freedom, which are described in the following two cases.

For translational degrees of freedom, in one embodiment, when setting the stiffness values of the virtual springs in the directions of the multiple degrees of freedom, in the direction of the translational degrees of freedom, the stiffness of the virtual springs in the depth direction is set. 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 lateral direction; the stiffness value of the virtual spring in the lateral 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 lateral direction are both less than or equal to the first translation preset stiffness threshold.

Exemplarily, the value range of the first translation preset stiffness threshold may be 0 N/m˜500 N/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 lateral 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 the actual situation. The principle is to set the stiffness smaller, because according to Hooke's law, when the force is constant, the smaller the stiffness, the larger the spring deformation. Therefore, setting the stiffness in the depth direction as small as possible can help the actuator to move in this direction to perform cutting. In the transverse direction Y, the rigidity of the setting is also relatively small, which also helps the actuator to 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 motion 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 in 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 flexibly set 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 rigidity 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 in the Z direction directly causes the actuator to deviate from the predetermined osteotomy plane, it is easy to cause problems to the patient. Injury, this is not allowed.

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

Taking the lateral Y as the stiffness value of the virtual spring in the rotational direction of the axis;

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

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

The stiffness value of the virtual spring in the rotational direction with the vertical direction Z as the axis is less than or equal to the first rotational 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 in the vertical direction Z as the axis,

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

Among them, the second rotation preset stiffness threshold is 200Nm/rad to 300Nm/rad, which limits the displacement of the actuator rotating with the depth direction X as the axis and the lateral Y axis as the axis, and further prevents the actuator from leaving the current target area. , to ensure the safety of osteotomy.

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

In one embodiment, the defining method further includes: setting damping values of the virtual spring in the directions of the 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, eg, 0.7.

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

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

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

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

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

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

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

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

The degrees of freedom of CartDOF.A to rotate around the Z axis;

CartDOF.B rotates degrees 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, by setting the stiffness to the maximum allowable value (5000) in the Z-axis direction, and setting the stiffness to a smaller value (0-500) in the X and Y directions, while 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 (0-100) in the direction A of the rotational degree of freedom around the Z-axis, so that the movement of the TCP point of the end-of-manipulator tool can be limited to On the XOY plane, it can rotate in a small range on the XOY plane.

The corresponding code is as follows:

CartesianImpedanceControlModeimpedanceMode=newCartesianImpedanceContr olMode();

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); All combinations of all Cartesian degrees of freedom, set the spring damping to 1;

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

In one embodiment, applied in knee replacement surgery, the above-mentioned target area includes: anterior femoral osteotomy plane, anterior oblique femoral osteotomy plane, posterior femoral condyle osteotomy plane, posterior oblique femoral osteotomy plane, distal femoral osteotomy plane End osteotomy plane and tibial osteotomy plane.

See Fig. 4A for a schematic diagram showing the comparison before and after osteotomy. Specifically, as shown in FIG. 4B , the dark gray coverage area is not the area to be osteotomy of the anterior end of the femur, which is the osteotomy plane of the anterior end of the femur after being cut off. Referring to Fig. 4C, the dark gray coverage area is the anterior oblique femoral osteotomy area, which is the anterior oblique femoral osteotomy plane after being cut off. Referring to Fig. 4D, the dark gray area is the area to be osteotomy of the posterior femoral condyle, which is the osteotomy plane of the posterior femoral condyle after the area is cut off. Referring to Fig. 4E, the dark gray area is the posterior oblique osteotomy plane of the femur after osteotomy. Referring to FIG. 4F , the dark gray area is the area to be osteotomy of the distal femur, which is the osteotomy plane of the distal femur after the area is cut off, and the light gray area is a schematic diagram of the saw blade. Referring to Figure 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, the model of the prosthesis needs to be determined before the operation, and the target area is determined according to the model of the prosthesis. In the second aspect, the present application also proposes a method for preoperative planning, which specifically includes the following steps:

After acquiring the medical image of the knee joint, perform segmentation and three-dimensional reconstruction on the medical image 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 bone parameters may include key bone anatomical points, bone key axes and bone size parameters, and the key bone anatomical points may be identified based on deep learning algorithms, such as neural network models, The identified key anatomical points of the bone are marked on the 3D bone model.

The bone size can include the left and right diameters of the femur, the anterior and posterior diameters of the femur, the left and right diameters of the tibia, and the anterior and posterior diameters of the tibia. The line connecting the medial and lateral edges of the tibia is determined, and the anterior and posterior diameters of the tibia are determined according to the line connecting the anterior and posterior edges 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. 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 3D skeletal prosthesis model can be a prosthesis model for total knee joint replacement currently on the market. There are many types of 3D skeletal prosthesis models, and each type of 3D skeletal prosthesis model has various models. For example, the types of three-dimensional femoral prosthesis models are ATTUNE-PS, ATTUNE-CR, SIGMA-PS150, etc., and the models of ATTUNE-PS are 1, 2, 3, 3N, 4, 4N, 5, 5N, 6, 6N.

Exemplarily, the implementation manner of the system determining the prosthesis model through the interactive interface may include: the configuration items of each 3D skeletal prosthesis model may be set on the interface, for example, the configuration items of the 3D femoral prosthesis model, the configuration items of the 3D tibial prosthesis model may be set. item and the configuration item of the 3D gasket model, when a certain configuration item is triggered (for example, the selected mode triggers the configuration item), the corresponding prosthesis library can be automatically matched, and then which prosthesis model in the prosthesis library is detected. Triggered to use the triggered prosthesis signal as a replacement prosthesis. For example, when the femoral prosthesis model configuration item is triggered, it can be associated with the femoral prosthesis library, and then the type and model of all prosthesis models in the femoral prosthesis library can be displayed on the interface, and then which type of femoral prosthesis is detected. The 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;

The placement position and placement angle of the 3D skeletal prosthesis model are adjusted based on the key skeletal parameters and the type and model of the 3D skeletal prosthesis model.

Specifically, in order to realize the three-dimensional visualization of the matching adjustment process and matching effect between the bone and the prosthesis. After obtaining the 3D skeletal model after implanting the 3D skeletal 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, femoral left-right diameter, and femoral anteroposterior diameter. Whether it is fitted with the 3D femur model.

Whether the tibial prosthesis model has been installed and fitted with the three-dimensional tibial model can be determined based on the tibial varus angle, the femoral valgus angle, the left-right diameter of the tibia, and the anterior-posterior diameter of the tibia.

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

The steps of adjusting the placement position and placement angle of the 3D skeletal prosthesis model based on the key skeletal parameters and the type and model of the 3D skeletal prosthesis model include:

Based on the left-right diameter of the femur and the anterior-posterior diameter of the femur, adjusting the placement position of the three-dimensional femoral prosthesis model;

adjusting the varus angle 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;

The internal rotation angle or the external rotation angle of the three-dimensional femoral prosthesis is adjusted so that the posterior femoral condyle angle PCA (the angle between the projection line of the femoral transcondylar line and the line connecting the posterior condyle in the transverse section) 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 rear of the femur, the installation position is appropriate.

The femoral valgus angle and femoral varus angle can be determined based on the current position of the femoral prosthesis model and the relative angle between the mid-axis of the femoral prosthesis model in the up-down direction on the coronal plane and the femoral line of force. The angle of external rotation and internal rotation was determined by the relative angle to the transcondylar line; the angle of femoral flexion was determined by the angle of the femoral mechanical axis and the central axis of the femoral prosthesis model in the sagittal anterior-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 that the femoral prosthesis model has an appropriate installation angle. Adjust the placement position and placement angle to a suitable position.

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

The steps of adjusting the placement position and placement angle of the 3D skeletal prosthesis model based on the key skeletal parameters and the type and model of the 3D skeletal prosthesis model include:

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

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 steps of adjusting the placement position and placement angle of the three-dimensional bone prosthesis model, the method further includes:

Based on the matching relationship between the 3D bone prosthesis model and the 3D prosthesis model, simulated osteotomy was performed to obtain a 3D skeletal postoperative simulation model;

performing motion simulation including extension position and flexion position on the three-dimensional femoral surgery simulation model;

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

Comparing the extension gap with the flexion gap, the three-dimensional skeletal prosthesis model is verified for matching.

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

After adjusting the placement position and placement angle of the 3D skeletal prosthesis model, a simulated osteotomy is performed based on the matching relationship between the 3D skeletal prosthesis model and the 3D skeletal model to obtain a 3D skeletal postoperative simulation model.

After obtaining the three-dimensional skeletal simulation model after surgery, the motion simulation can be performed, and the extension gap and flexion gap can be determined through the simulation map of extension position and flexion position. Based on the extension gap and flexion gap, determine whether the 3D bone prosthesis model fits the 3D bone model after osteotomy. 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 misalignment of the prosthesis, and then can accurately determine whether the prosthesis fits the bone. The user can use the final simulated image to determine whether the skeletal prosthesis model needs to be adjusted. If the type and model of the skeletal prosthesis are changed, the prosthesis library can be recalled, and the replaced 3D model can be generated based on the new skeletal prosthesis model. Bone surgery simulation model. By simulating the expected effect after surgery, the final skeletal prosthesis model can be more closely matched to the patient's knee joint.

In this embodiment, the post-operative simulation of the bone model on which the prosthesis model is installed can accurately determine the gap, thereby overcoming the technique and experience of the surgeon in the related art, and the indicators such as gap balance and the installation of the prosthesis position are completely dependent on the Subjective sensations are 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 femur model; creating an intramedullary positioning simulation rod by a circular fitting method; using the intramedullary positioning simulation rod Determine the femoral opening point.

In an optional implementation manner, it is also necessary to determine the position of the needle insertion point of the femoral intramedullary positioning simulation rod during knee replacement, wherein the apex of the intercondylar fossa can be used as the position of the needle insertion point of the intramedullary positioning simulation rod. The position of the point can be used as the opening point of the femur. During the operation, the intramedullary positioning simulation rod and the femoral opening point were visualized on the 3D bone model to guide the surgeon 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, the present application also proposes a method for bone registration, which specifically includes the following step:

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

Roughly register the spatial position of the preoperative planning point under the three-dimensional coordinate system with the spatial position of the intraoperative marker point under the world coordinate system to obtain a rough registration matrix;

Obtaining the spatial position of the dashed point set on the target bone of the entity's knee joint under the world coordinate system; according to the rough registration matrix, the spatial position of the dashed point set under the world coordinate system is compared with the three-dimensional model Perform fine registration to register the world coordinate system to the 3D model coordinate system.

Specifically, the three-dimensional model refers to the skeletal model of the knee joint. The preoperative planning point is the point that is pre-planned in the three-dimensional model for registration. Intraoperative markers are points that the doctor marks on the bone surface during surgery.

Before surgery, preoperative planning points are determined on the bones in the 3D model of the knee joint. The three-dimensional model may specifically include a three-dimensional femur model and a three-dimensional tibia model. During knee replacement surgery, the patient is in a supine position, and the doctor can implant fixation pins on each bone of the patient's knee joint and install a tracer on each bone. Then, the medial approach of the knee joint was taken, the skin and subcutaneous tissue were incised, and the tibial plateau was fully exposed by entering the joint, and the bones of the knee joint were registered in turn.

In the process of bone registration, the optical navigation and positioning system obtains the spatial position of the preoperative planning points on the bones in the three-dimensional model of the knee joint under the coordinate system of the three-dimensional model, and the intraoperative marking points on the bones of the solid knee joint in the world. The spatial position in the coordinate system. For example, 40 bone anchor points can be collected as intraoperative markers.

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

For rough registration, in one embodiment, the performing rough registration between 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 3D space point cloud search method, the spatial position of the preoperative planning point in the 3D 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;

By using a preset three-dimensional space point cloud search method, the preoperative planning points are corrected according to the planning triangle sequence, and the corrected preoperative planning points are obtained;

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

In one embodiment, the pre-operative planning point under the three-dimensional coordinate system and the intraoperative marked point under the world coordinate system are respectively searched in a preset three-dimensional space point cloud search method. Perform triangulation processing to obtain the actual operation triangle sequence corresponding to the intraoperative marker points and the planning triangle sequence corresponding to the preoperative planning points, including:

By using a preset 3D space point cloud search method, the first three points of the preoperative planning point are formed into a triangle according to the spatial position of the preoperative planning point in the 3D coordinate system, and according to the intraoperative marking point in the world coordinate system The first three points of the intraoperative marked points form a triangle in the spatial position below;

Starting from the fourth point, two points are respectively selected from the previous points to form a triangle with the current point, and the practical operation triangle sequence corresponding to the marked points in the operation and the planning triangle sequence corresponding to the preoperative planning points are obtained; the practical operation The triangle sequence and the triangle composition order of the planning triangle sequence are the same.

In one embodiment, the preoperative planning points are modified according to the planning triangle sequence by using a preset three-dimensional space point cloud search method, and the modified preoperative planning points obtained include:

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

Screen out the second target point in the second neighborhood space point set;

The spatial position of the preoperative planning point in the three-dimensional model coordinates is corrected to a 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 fine registration stage, no preoperative planning is required. During the operation, a surface calibration device such as a surgical probe can be used to perform a scribing operation on the surface of each bone of the solid knee joint. Line point set. Wherein, the scribed area to be scribed is the key bone area on the surface of each bone, that is, the area including the key bone points.

Specifically, the dash point set is composed of points on multiple line segments, for example, points in three line segments may be included. The points in the set of dashed points are paired in a triangle, and a point is selected in each line segment, and every three points form a triangle. The paired triangle sequence includes multiple triangles.

Exemplarily, the position of the tracer on the surgical probe is tracked by the tracking camera in the optical navigation and positioning system, and the probe tracer on the surgical probe obtained by the tracking camera is in world coordinates during the scribing process. The space position under the system is determined, and the space position of the line point set on each bone of the knee joint of the entity is determined in the world coordinate, so as to obtain the line point set.

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

In the process of fine registration, the neighborhood space point set of the dash point set on the 3D model can be determined first, so that the dash point set can be assigned according to the neighborhood space point set and the spatial position of the dash point set in the world coordinate system. The spatial position under the three-dimensional model coordinate system is corrected, and then the corrected dash point set and the space position of the dash point set under the world coordinate system are registered.

In an embodiment, the performing fine registration of the spatial position of the dashed point set in the world coordinate system with the three-dimensional model according to the rough registration matrix includes:

Reflecting the spatial position of the dash point set in the world coordinate system back into the 3D model coordinate system according to the rough registration matrix, to obtain the position of the dash point set in the 3D model coordinate system;

Perform a neighborhood space search on the 3D model according to the position of the dash point set in the 3D model coordinate system to obtain a first neighborhood space point set;

Correct the spatial position of the dash point set in the world coordinate system according to the first neighborhood space point set to obtain a line segment point set; perform precise registration on the line segment point set and the three-dimensional model.

Specifically, the rough registration matrix represents the conversion relationship between the world coordinate system obtained by the rough registration and the three-dimensional model coordinate system. According to the rough registration matrix, the spatial position of the dash point set in the world coordinate system can be reflected back into the 3D model coordinate system, so as to obtain the position of the dash point set in the 3D model coordinate system. Since the 3D model corresponds to the 3D model coordinate system, a 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 line point set under the three-dimensional model coordinate system.

In an embodiment, the modifying the spatial position of the dashed point set in the world coordinate system according to the first neighborhood spatial point set includes:

The points in the dash point set are triangularly paired to obtain a paired triangle sequence; the points in the dash point set are corrected according to the first neighborhood space point set and the paired triangle sequence;

The step specifically includes: screening out a first target point in the first neighborhood space point set; and correcting the position of the point in the dashed point set to a position corresponding to the first target point according to the paired triangle sequence.

Specifically, the dash point set is composed of points on multiple line segments, for example, points in three line segments may be included. The points in the set of dashed points are paired in a triangle, and a point is selected in each line segment, and every three points form a triangle. The paired triangle sequence includes multiple triangles.

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 point. A set of target points. The preset screening strategy is that the triangle formed by the three screened target points and the triangle in the paired triangle sequence are congruent triangles. Since the error of congruent triangles is extremely small, the spatial positions of the three triangle points of the current triangle in the three-dimensional model coordinates can be respectively corrected to the positions of the corresponding target points in the first target point set, and the correction process is repeated to realize the matching of the three triangles in the sequence. A large number of triangles continuously correct the spatial position of the dash point set in the 3D model coordinate system, so that the spatial position of the dash point set reflected in the 3D model coordinate system is more accurate.

Afterwards, the corrected dash point set and the space position of the dash point set in the world coordinate system are registered by the registration algorithm, and the registration result is obtained. For example, the registration algorithm may be ICP (Iterative Closest Point). The registration result can be the conversion relationship between the finally obtained world coordinate system and the three-dimensional coordinate, and the accuracy of the intraoperative operation can be improved through the registration result.

In this embodiment, the spatial position of the set of dashed points on each bone of the knee joint of the entity in the world coordinate system is obtained through the dashing operation, so that the set of dashed points is set in the world coordinate system according to the rough registration matrix Compared with the traditional point registration algorithm, the registration efficiency is greatly improved, and the registration accuracy is also greatly improved.

target area target area target area target area target area target area target area target area target area target area The control method of the surgical robot manipulator includes the following steps:

During the operation of the actuator at the end of the robotic 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 robot that needs to perform osteotomy, such as a total knee replacement robot), and the robot may mainly include a robotic arm, and (in a detachable manner) an execution device provided at the end of the robot The actuator may be an osteotomy saw. The main control system of the host computer can send an osteotomy start signal to the manipulator, and after the manipulator receives the signal, it drives the osteotomy saw at its end to move.

The end of the robotic arm and the actual area to be osteotomy (for example, the femoral area of the knee joint, the tibia area) can be preset with a tracer. The tracer includes a light-sensing ball that emits infrared rays, and is tracked in real time by a binocular infrared camera The position of the light-sensing ball set at the end of the manipulator, the position of the light-sensing ball on the femur area, and the position of the light-sensing ball on the tibia 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 then 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.

The pre-planned osteotomy sequence is displayed in the 3D model, and the current target area is a target area selected from multiple target areas in response to the operator.

As an optional implementation manner 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 operated displacement of the manipulator according to the position difference; displays the displacement corresponding to the displacement in the three-dimensional model The indicated adjustment information, so that the operator operates the robotic arm according to the indicated 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 at 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 indicated adjustment information corresponding to the displacement amount may include the adjustment path corresponding to the displacement amount displayed by the enlarged target area of the target area, and guide the doctor to hold the robotic arm to adjust the plane of the actuator to align with the osteotomy plane (the actuator is in the cutting plane). The outer edge of the bone plane, the actuator is roughly coplanar with the osteotomy plane).

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

When the actuator is running, the Cartesian damping control mode based on the virtual spring and damper is activated. The offset Δx of Δx outputs a feedback force F opposite to the operated direction, F=Δx*C, thereby limiting the movement of the actuator within the current target area.

The magnitude of the preset stiffness value C in the direction of each degree of freedom is as described above, and will not be repeated here.

target area target area target area target area target area target area target area target area Schematic diagram of the structure; the system includes:

The model establishment module 61 is used for establishing the stiffness-damping model of the virtual spring 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 the directions of multiple degrees of freedom;

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

The stiffness setting module 62 is further configured to, in the direction of the translational degree of freedom, 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 lateral direction;

The stiffness value of the virtual spring in the lateral 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 lateral 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 Translate the preset stiffness threshold.

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 with the depth direction as the axis of rotation, and the transverse direction as the axis of rotation The stiffness value of the virtual spring on the vertical direction and the stiffness value of the virtual spring in the rotation direction of the axis;

The stiffness value of the virtual spring in the rotational direction of the axis is smaller than the stiffness value of the virtual spring in the rotational direction of the axis, and is smaller than the stiffness of the virtual spring in the rotational direction of 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 rotational direction of the axis with the depth direction as the axis and the stiffness value of the virtual spring in the rotational direction of the axis with the lateral direction are greater than or equal to the second rotational preset stiffness threshold.

In one embodiment, the stiffness setting module 62 is further configured to set the first translation preset rigidity threshold to be 0N/m～500N/m, and the second translation preset rigidity threshold to be 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 the 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 a sixth aspect, the present application also proposes a device for defining a motion plane of a robot, refer to the schematic structural diagram of the device for defining a motion plane of a robot 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 execute one or more program instructions, so as to execute any of the steps described above.

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

Various methods, steps, and logical block diagrams disclosed in the embodiments of the present invention can 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 conjunction with the embodiments of the present invention may be directly embodied as executed by a hardware decoding processor, or executed by a combination of hardware and software modules in the decoding processor. The software module may be located in random access memory, flash memory, read-only memory, programmable read-only memory or electrically erasable programmable memory, registers and other storage media mature in the art. The processor reads the information in the storage medium, and completes the steps of the above method in combination with its hardware.

The storage medium may be memory, eg, may be volatile memory or nonvolatile memory, or may include both volatile and nonvolatile memory.

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

The volatile memory may be a random access memory (Random Access Memory, RAM for short), which is used as an external cache. By way of example and not limitation, many forms of RAM are available, such as Static Random Access Memory (SRAM), Dynamic RAM (DRAM), 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 invention is intended to include, but not limited to, these and any other suitable types of memory.

Obviously, those skilled in the art should understand that the above-mentioned modules or steps of the present invention can be implemented by a general-purpose computing device, and they can be centralized on a single computing device or distributed in a network composed of multiple computing devices Alternatively, 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 the computing device, or they can be made into individual integrated circuit modules, or they can be integrated into The multiple modules or steps are fabricated into a single integrated circuit module. As such, the present invention is not limited to any particular 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, the present application may have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of this application shall be included within the protection scope of this application.

Claims (10)

1. A method for defining a robot motion area, comprising:

establishing a stiffness-damping model of a virtual spring according to displacement offsets of an actuator at the tail end of a mechanical arm of the robot in the directions of multiple degrees of freedom from an actual position;

setting stiffness values of each of the virtual springs in a plurality of degrees of freedom to define movement of the actuator over a pre-planned target area;

the direction of the actuator cutting into the target area is recorded as a depth direction, the direction in the target area and perpendicular to the depth direction is recorded as a transverse direction, and the direction perpendicular to the target area is recorded as a vertical direction;

setting stiffness values of each of the virtual springs in a plurality of degrees of freedom directions, including:

setting 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 the direction of translational freedom;

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 smaller than or equal to a first translational preset stiffness threshold, and the stiffness value of the virtual spring in the vertical direction is larger than or equal to a second translational preset stiffness threshold;

the first translation preset rigidity threshold value is 0N/m-500N/m;

the second translational preset stiffness threshold value is 4000N/m-5000N/m.

2. The method of defining a robot motion zone of claim 1,

the stiffness value of the virtual spring in the depth direction is equal to or less 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.

3. The method of claim 2, wherein setting stiffness values of each of the virtual springs in a plurality of degrees of freedom comprises:

setting, in a rotational degree of freedom direction, a stiffness value of a virtual spring in a direction of axial rotation with the depth direction as an axis, a stiffness value of a virtual spring in a direction of axial rotation with the lateral direction as an axis, and a stiffness value of a virtual spring in a direction of axial rotation with the vertical direction as an axis;

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

the stiffness value of the virtual spring taking the vertical direction as the axis rotation direction is smaller than or equal to a first rotation preset stiffness threshold value;

and the rigidity value of the virtual spring taking the depth direction as the shaft rotation direction and the rigidity value of the virtual spring taking the transverse direction as the shaft rotation direction are greater than or equal to a second rotation preset rigidity threshold value.

4. The method of defining a robot motion zone of claim 3,

the first rotational preset stiffness threshold is 0 Nm/rad-20 Nm/rad;

the second rotation preset rigidity threshold value is 200 Nm/rad-300 Nm/rad.

5. The method of defining a robot motion zone of claim 1, further comprising: damping values of the virtual spring in a plurality of degrees of freedom are set.

6. The method of defining a robot motion zone of claim 1,

the target area includes: a femoral anterior resection plane, a femoral anterior oblique resection plane, a femoral posterior condylar resection plane, a femoral posterior oblique resection plane, a femoral distal resection plane, and a tibial resection plane.

7. A system for defining a robot motion field, comprising:

the model establishing module is used for establishing a stiffness-damping model of the virtual spring according to displacement offsets of an actuator at the tail end of a mechanical arm of the robot in the directions of multiple degrees of freedom and an actual position;

a stiffness setting module for setting stiffness values of each of the virtual springs in a plurality of degrees of freedom to define movement of the actuator on a pre-planned target area;

the direction of the actuator cutting into the target area is recorded as a depth direction, the direction in the target area and perpendicular to the depth direction is recorded as a transverse direction, and the direction perpendicular to the target area is recorded as a vertical direction;

the stiffness setting module is further used for setting 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 the direction of translational freedom;

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 smaller than or equal to a first translational preset stiffness threshold, and the stiffness value of the virtual spring in the vertical direction is larger than or equal to a second translational preset stiffness threshold;

the rigidity setting module is also used for setting the first translational preset rigidity threshold value to be 0N/m-500N/m and the second translational preset rigidity threshold value to be 4000N/m-5000N/m.

8. The system for defining a robot motion zone of claim 7,

the stiffness value of the virtual spring in the depth direction is equal to or less 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.

9. An electronic device, comprising: at least one processor and at least one memory; the memory is to store one or more program instructions; the processor, configured to execute one or more program instructions to perform the method of any of claims 1-6.

10. A computer-readable storage medium having one or more program instructions embodied therein for performing the method of any of claims 1-6.

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