Solution for uninterrupted man-machine workflow coupling based on variable virtual fixture

Abstract

The invention discloses a solution for uninterrupted man-machine workflow coupling based on a variable virtual fixture, which belongs to the technical field of man-machine interaction and comprises the following steps: S1, dividing workflows in a laboratory into manual operation workflows and automatic workflows; s2, the control torque of the master robot and the slave robot in the teleoperation system is calculated, and when the slave robot tracks the motion trail of the master robot, the interaction torque of the slave robot and the environment is transmitted to the master robot; s3, setting a virtual fixture with a variable shape; s4, calculating the moment applied by the virtual fixture; s5, the moment of force of the virtual clamp is introduced into a teleoperation system, and interference-free coupling in man-machine workflow is achieved; according to the solution method for uninterrupted man-machine workflow coupling based on the variable virtual fixture, on the basis of not interfering and interrupting the automatic workflow, the manual operation workflow is added, meanwhile, people are prevented from making contact with the harmful environment, and the good man-machine interaction performance and safety of the system are guaranteed.

Description

Technical Field

[0001] The invention relates to the technical field of human-computer interaction, and in particular to a solution for non-interruption human-computer workflow coupling based on a variable virtual fixture. Background Art

[0002] A collaborative robot (Cobot) is a robot that can work safely and efficiently with humans in the same workspace. Unlike traditional industrial robots, Cobots are usually more flexible and intelligent, and can interact with humans through perception and learning. However, existing Cobots still face many challenges in complex and dynamic working environments, especially in scenarios that require highly flexible human-machine interaction, such as continuity of operation, seamless connection of workflows, and safety of human-machine collaboration. The experimental processes in biomedical laboratories are usually highly complex and dynamic, involving a large number of manual operations and real-time interventions, which puts higher requirements on existing automated robot systems, and most of the existing automated laboratories are aimed at fully automated workflows. The prior art can refer to the patents with announcement numbers CN202411365422.9 and CN202420609105.6, which are all aimed at the development of automated workflows, such as precise positioning, sample processing, etc., without taking into account workflows that require human operation. Once people join the workflow, the automated tasks will be disturbed.

[0003] A virtual fixture is a computer-generated auxiliary device that provides constraints, guidance or assistance during robot operation through software algorithms, simulating the functions of actual physical fixtures. The prior art proposes a solution for robot-assisted craniotomy under manual guidance, which divides the robot-assisted drilling task into two stages: alignment and drilling. Machine learning is used to identify the doctor's intentions and realize the conversion of different virtual fixtures in the drilling and alignment stages. The human-computer interaction workflow in the laboratory is relatively standardized compared to the surgical process, such as using a pipette to inject liquid into a test tube in an automated workflow, or taking away a specific sample from a large batch of samples in an automated workflow. These processes do not require complex machine learning algorithms to identify human intentions. At the same time, the computing power required for machine learning is high and it is not universal. Summary of the invention

[0004] The purpose of the present invention is to provide a solution for non-interruption human-machine workflow coupling based on a variable virtual fixture, so as to solve the problems existing in the above-mentioned background technology.

[0005] To achieve the above object, the present invention provides a solution for non-interruption human-machine workflow coupling based on a variable virtual fixture, comprising the following steps:

[0006] S1. The workflow in the laboratory is divided into manual operation workflow and automated workflow. The manual operation workflow avoids direct contact between the operator and the harmful environment and adopts a remote control mode, including a master robot and a slave robot;

[0007] S2, calculating the control torque of the master robot and the slave robot in the teleoperation system, and transmitting the interaction torque between the slave robot and the environment to the master robot while the slave robot tracks the motion trajectory of the master robot;

[0008] S3. Setting a virtual fixture of a variable shape, whose posture is updated according to the movement of the object operated in the automated workflow, and whose shape is determined according to the stage of the operation, for applying a guiding force to the operator controlling the main robot;

[0009] S4, calculating the torque applied by the virtual fixture;

[0010] S5. Introduce the torque of the virtual fixture into the teleoperation system to achieve interference-free coupling in the human-machine workflow.

[0011] Preferably, in step S1, under the influence of the external torque applied by the operator and the environment, according to the ideal environmental impedance characteristic Determine the desired master robot motion, where q md , and They represent the expected position, velocity, and acceleration of the main robot in the joint space, respectively. m and Respectively represent the current position and speed of the main robot, M e and C e is the ideal environmental impedance parameter, G m is the gravitational torque, τ h is the torque applied by the operator to the master robot, τ e is the torque from the interaction between the robot and the environment, including the torque τ of the real environment r and the guiding torque τ of the virtual fixture vf .

[0012] Preferably, in step S2, the control torque of the master robot at this time is obtained through the torque controller according to the error between the current position of the master robot and the expected position; due to the influence of communication, the position information transmitted to the slave robot has high-frequency noise, which is first passed through a low-pass filter to obtain the expected movement of the slave robot, and then the control torque of the slave robot at this time is obtained through the torque controller according to the error between the current position of the slave robot and the expected position, and interacts with the environment; wherein the torque controller is realized by anti-stepping control based on Lyapunov stability criterion, and the control torque calculation formula of the master robot and the slave robot is as follows:

[0013]

[0014] Among them, τ m and τ s The control torque of the master robot and the slave robot; q m , and q s , The position and speed of the master robot and the slave robot; q md , and is the desired position, velocity, and acceleration of the master robot; q sd , and are the desired position, velocity, and acceleration of the slave robot; μ1, μ2, μ1′, and μ2′ are the control parameters of the master and slave robot controllers that are greater than zero; C m and C s Coriolis force and centripetal force matrices of the master robot and the slave robot; M m and M s Inertia matrices of the master and slave robots.

[0015] Preferably, in step S2, since the interaction force between the force applied by the operator and the real environment is measured by a force sensor, a corresponding dead zone is introduced to reduce the offset and measurement error of the force sensor. When the measured force is lower than a specific threshold, the force is regarded as zero, and the impedance characteristic parameter M of the environment is increased. e and C e .

[0016] Preferably, in step S3, in an actual laboratory human-machine collaborative workflow, a common operation is to use a pipette to extract a liquid sample from a running automated workflow, which is divided into two stages: an alignment stage of aligning the pipette with a specific test tube on a test tube rack and an insertion stage of inserting the pipette downward for subsequent operations. A variable-shape virtual fixture is designed for these two stages, and the two variable shapes include: in the alignment stage, the working area is large and the position of the operation object is relatively concentrated, and a funnel-shaped virtual fixture is used. The funnel-shaped virtual fixture limits the working area of ​​the slave robot to the range of the test tube rack, which is convenient for the operator to remotely operate the slave robot to select the test tube for extracting the required liquid in the test tube rack, and ensure that the funnel moves with the movement of the automation end; after selecting a specific test tube, the operator uses a button to change the virtual fixture into a cylindrical shape, which will be generated at the position of the selected test tube, while keeping the working area of ​​the slave robot consistent with the moving automation end, and limiting the direction of the tool at the end of the slave robot to remain aligned with the test tube.

[0017] Preferably, the shape of the virtual fixture is switched according to different task stages. If it is the alignment stage, the virtual fixture is set to a funnel shape formed by a hyperboloid, and the posture constraint on the slave robot is not enabled; if it is the insertion stage, the virtual fixture is set to a cylindrical shape and the posture constraint is enabled.

[0018] Preferably, in step S4, calculating the torque applied by the virtual fixture through the geometric relationship of the virtual fixture includes:

[0019] S41, Pose based on virtual fixture vf , that is, the center position of the bottom circle of the funnel or cylinder Pos vf (x vf ,y vf ,z vf ) and the normal vector n vf (n x ,n y ,n z ) to obtain the equation of the bottom plane:

[0020] n x (xx vf )+n y (yy vf )+n z (zz vf )=0;

[0021] Then it is converted into the form of Ax+By+Cz+D=0, where [A,B,C,D]=[n x ,n y ,n z ,-n x x vf -n y y vf -n z z vf ];

[0022] S42, calculate the current tool center position Pos of the robot tcp (x tcp ,y tcp ,z tcp ) and the distance from the bottom plane:

[0023]

[0024] S43, calculate the center point position of the plane in the virtual fixture where the slave robot is currently located:

[0025] Pos c =Pos vf +d p n vf ;

[0026] S44. Determine the radius of the current plane circle based on the shape of the virtual fixture:

[0027]

[0028] If it is a hyperbolic funnel, the radius is r c If it is cylindrical, the radius is the preset bottom radius r b , where k vf Determine the size of the funnel opening;

[0029] S45. Calculate the force direction vector:

[0030] forceVec=Pos c -Pos tcp ;

[0031] S46. Calculate the force applied by the virtual fixture based on the spring damping model:

[0032] F vf =K*forceVec-D*Vel tcp ;

[0033] Among them, K and D are the spring damping coefficients of the virtual fixture, Vel tcp is the velocity of the tool center point.

[0034] Preferably, if the posture constraint is enabled, the posture of the current slave robot end tool and the set virtual fixture direction vector n are calculated. vf The clamp is then used to calculate the torque applied to the slave robot in the same way as step S46. The torque is combined with the force calculated in step S46 to obtain the Wrench vf ; Calculate τ through the robot force Jacobi vf :

[0035] τ vf =J T *Wrench vf ;

[0036] Where J is the Jacobian matrix of the robot.

[0037] Therefore, the present invention adopts the above-mentioned solution of non-interruption human-machine workflow coupling based on variable virtual fixture, which has the following beneficial effects:

[0038] (1) The operator and the harmful environment are separated through the teleoperation control framework, and the shape-changing virtual fixture technology is introduced to integrate the manual operation workflow without interfering with the existing automated workflow, thus realizing an uninterrupted human-machine workflow coupling system, which effectively improves the continuity and operational efficiency of human-machine collaboration;

[0039] (2) The variable virtual fixture can dynamically adjust its shape and function according to the different stages of the workflow to adapt to the highly complex and dynamically changing operational requirements in biomedical laboratories. This enables the robotic system to respond flexibly in a variety of experimental environments, significantly improving its scope of application and practicality.

[0040] (3) This method is a universal teleoperation robot solution that is applicable to a variety of different biomedical experimental processes and has good scalability and adaptability; this enables the system to meet the specific needs of different laboratories and promote the widespread application of robotics technology in intelligent biomedical laboratories.

[0041] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 A block diagram of a remote control system for solving the problem of non-interruption human-machine workflow coupling based on a variable virtual fixture according to the present invention;

[0043] Figure 2 It is a schematic diagram of a funnel-shaped virtual fixture in the alignment stage of the present invention;

[0044] Figure 3 It is a schematic diagram of a cylindrical virtual fixture in the insertion stage of the present invention;

[0045] Figure 4 Schematic diagram of the geometric relationship of the virtual fixture of the present invention. DETAILED DESCRIPTION

[0046] The following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0047] A solution for non-interruption human-machine workflow coupling based on a variable virtual fixture includes the following steps:

[0048] S1. The workflow in the laboratory is divided into manual operation workflow and automated workflow. The manual operation workflow avoids direct contact between the operator and the harmful environment and adopts a remote control mode, such as Figure 1 As shown, it includes a master robot and a slave robot; under the influence of the external torque applied by the operator and the environment, according to the ideal environmental impedance characteristics Determine the desired master robot motion, where q md , and They represent the expected position, velocity, and acceleration of the main robot in the joint space, respectively. m and Respectively represent the current position and speed of the main robot, M e and C e is the ideal environmental impedance parameter, G m is the gravitational torque, τ h is the torque applied by the operator to the master robot, τ e is the torque from the interaction between the robot and the environment, including the torque τ of the real environment r and the guiding torque τ of the virtual fixture vf .

[0049] S2. According to the error between the current position of the master robot and the expected position, the control torque of the master robot is obtained through the torque controller. Due to the influence of communication, the position information transmitted to the slave robot has high-frequency noise. It first passes through a low-pass filter to obtain the expected movement of the slave robot. Then, according to the error between the current position of the slave robot and the expected position, the control torque of the slave robot is obtained through the torque controller, and interacts with the environment. The torque controller is realized by anti-stepping control based on the Lyapunov stability criterion. The control torque calculation formula of the master robot and the slave robot is as follows:

[0050]

[0051] Among them, τ m and τ s The control torque of the master robot and the slave robot; q m , and q s , The position and speed of the master robot and the slave robot; q md , and is the desired position, velocity, and acceleration of the master robot; q sd , and are the desired position, velocity, and acceleration of the slave robot; μ1, μ2, μ1′, and μ2′ are the control parameters of the master and slave robot controllers that are greater than zero; C m and C s Coriolis force and centripetal force matrices of the master robot and the slave robot; M m and M s Inertia matrices of the master and slave robots.

[0052] In addition, since the interaction force between the operator's force and the real environment is measured by a force sensor, a corresponding dead zone is introduced to reduce the offset and measurement error of the force sensor. When the measured force is lower than a certain threshold, the force is considered to be zero, and the impedance characteristic parameter M of the environment is increased. e and C e .

[0053] S3. In an actual laboratory human-machine collaborative workflow, a common operation is to use a pipette to extract a liquid sample from an automated workflow in operation. In this embodiment, this example is used to illustrate that this process is divided into two stages: an alignment stage of aligning the pipette with a specific test tube on a test tube rack and an insertion stage of inserting the pipette downward for subsequent operations. Therefore, a variable-shape virtual fixture is designed for these two stages, and the position and posture of the virtual fixture will be updated with the movement of the object being operated in the automated workflow, such as Figure 2-Figure 3 As shown, the two variable shapes include: a funnel-shaped virtual fixture during the alignment stage. During the alignment stage, the working area is larger and the position of the operation object is relatively concentrated. The funnel-shaped virtual fixture limits the working area of ​​the slave robot to the range of the test tube rack, which is convenient for the operator to remotely operate the slave robot to select the test tube for the required extraction liquid in the test tube rack, and ensure that the funnel moves with the movement of the automation end. After selecting a specific test tube, the operator uses a button to change the virtual fixture into a cylindrical shape, which will be generated at the position of the selected test tube. While keeping the working area of ​​the slave robot consistent with the moving automation end, the direction of the tool at the end of the slave robot is limited to remain aligned with the test tube.

[0054] The main purpose of the virtual fixture is to apply guiding force to the operator of the master robot through an algorithm to ensure that the workspace of the slave robot holding the tool can track the movement of the automated workflow, thereby coupling the manual operation workflow with the automated workflow without interference.

[0055] S4. Calculate the torque applied by the virtual fixture through the geometric relationship of the virtual fixture, such as Figure 4 As shown, the pose of the virtual fixture is vf , that is, the center position of the bottom circle of the funnel or cylinder Pos vf and the normal vector n vf , which can be adjusted dynamically according to the position of the automation end at that moment. There are many ways to obtain the motion position of the automation end: such as using computer vision to use a depth camera to recognize the QR code attached to the automation end; or calibrating the coordinate system of the automation end and the coordinate system of the robot in the interactive end teleoperation system in advance. Since the motion trajectory of the automation end is pre-programmed, the motion trajectory can be directly converted to the coordinate system of the teleoperation system through the calibrated position relationship. The radius of the bottom base circle is r b, which can be determined by the size of the required workspace, such as the radius of the test tube, the radius of the test tube rack section circle, etc. The shape of the virtual fixture can be switched according to the different task stages. If it is the alignment stage, the virtual fixture is set to a funnel shape formed by a hyperboloid, and the posture constraint on the slave robot is not enabled; if it is the insertion stage, the virtual fixture is set to a cylindrical shape and the posture constraint is enabled. The calculation process is:

[0056] S41, Pose based on virtual fixture vf , that is, the center position of the bottom circle of the funnel or cylinder Pos vf (x vf ,y vf ,z vf ) and the normal vector n vf (n x ,n y ,n z ) to obtain the equation of the bottom plane:

[0057] n x (xx vf )+n y (yy vf )+n z (zz vf )=0;

[0058] Then it is converted into the form of Ax+By+Cz+D=0, where [A,B,C,D]=[n x ,n y ,n z ,-n x x vf -n y y vf -n z z vf ];

[0059] S42, calculate the position Pos of the current tool center point (TCP) of the robot tcp (x tcp ,y tcp ,z tco ) and the distance from the bottom plane:

[0060]

[0061] S43, calculate the center point position of the plane in the virtual fixture where the slave robot is currently located:

[0062] Pos c =Pos vf +d p n vf ;

[0063] S44. Determine the radius of the current plane circle based on the shape of the virtual fixture:

[0064]

[0065] If it is a hyperbolic funnel, the radius is r c If it is cylindrical, the radius is the preset bottom radius r b , where k vf Determine the size of the funnel opening;

[0066] S45. Calculate the force direction vector:

[0067] forceVec=Pos c -Pos tcp ;

[0068] S46. Calculate the force applied by the virtual fixture based on the spring damping model:

[0069] F vf =K*forceVec-D*Vel tcp ;

[0070] Among them, K and D are the spring damping coefficients of the virtual fixture, Vel tcp is the velocity of the tool center point.

[0071] S47, if the posture constraint is enabled, calculate the current posture of the end tool of the slave robot and the set virtual fixture direction vector n vf The clamp is then used to calculate the torque applied to the slave robot in the same way as in step S46; the torque is combined with the force calculated in S46 to obtain the Wrench vf .

[0072] S48, calculate τ through the robot force Jacobi vf :

[0073] τ vf =J T *Wrench vf ;

[0074] Where J is the Jacobian matrix of the robot.

[0075] In principle, the virtual fixture in this embodiment can be replaced with various geometric shapes, such as a cone, a cuboid, etc., and it is only necessary to replace the corresponding geometric shape when calculating the force vector part. However, in order to fit the actual application background of this embodiment, the virtual fixture in the present invention adopts two shapes: a funnel shape and a cylinder.

[0076] S5. Apply the torque of the virtual fixture to the slave robot to achieve interference-free coupling in the human-machine workflow. Without stopping the automated workflow, the teleoperation system with the variable virtual fixture is used to provide the operator with guidance synchronized with the automated workflow movement.

[0077] Therefore, the present invention adopts the above-mentioned solution of non-interruption human-machine workflow coupling based on variable virtual fixtures, and realizes a solution that seamlessly integrates manual operation workflow into the system without interfering with and interrupting various existing laboratory automation workflows. At the same time, the system can prevent the operator from directly contacting the harmful environment, ensuring that the system has excellent human-machine interaction performance and high safety. The operator controls the main robot through the remote operation terminal while being away from the harmful environment, thereby commanding the slave robot to perform specific operations and interacting with the automated workflow. The virtual fixture can dynamically adjust its shape according to different workflow stages, and synchronously transmit the movement of the automated workflow to the operator through force guidance, so as to achieve the continuity and smoothness of human-machine collaboration without interfering with the existing automated workflow. The control algorithm adopted by the system has a small computational burden, which ensures its universality and real-time performance in various laboratory environments and can adapt to diverse operational requirements.

[0078] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solution of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of the present invention.

Claims

1. A solution for non-interruption human-machine workflow coupling based on variable virtual fixtures, characterized in that: The following steps are involved: S1. The workflow in the laboratory is divided into manual operation workflow and automated workflow. The manual operation workflow adopts the remote control mode, including the master robot and the slave robot; S2, calculating the control torque of the master robot and the slave robot in the teleoperation system, and transmitting the interaction torque between the slave robot and the environment to the master robot while the slave robot tracks the motion trajectory of the master robot; S3. Setting a virtual fixture of a variable shape, whose posture is updated according to the movement of the object operated in the automated workflow, and whose shape is determined according to the stage of the operation, for applying a guiding force to the operator controlling the main robot; S4, calculating the torque applied by the virtual fixture; S5. Introduce the torque of the virtual fixture into the teleoperation system to achieve interference-free coupling in the human-machine workflow.

2. The solution for non-interruption human-machine workflow coupling based on variable virtual fixture according to claim 1 is characterized in that: In step S1, under the influence of external torque applied by the operator and the environment, according to the ideal environmental impedance characteristic Determine the desired master robot motion, where q md , and They represent the expected position, velocity, and acceleration of the main robot in the joint space, respectively. m and Respectively represent the current position and speed of the main robot, M e and C e is the ideal environmental impedance parameter, G m is the gravitational torque, τ h is the torque applied by the operator to the master robot, τ e is the torque from the interaction between the robot and the environment, including the torque τ of the real environment r and the guiding torque τ of the virtual fixture vf .

3. The solution for non-interruption human-machine workflow coupling based on variable virtual fixture according to claim 2 is characterized in that: In step S2, the control torque of the master robot is obtained by the torque controller according to the error between the current position of the master robot and the expected position; due to the influence of communication, the position information transmitted to the slave robot has high-frequency noise, which is first passed through a low-pass filter to obtain the expected movement of the slave robot, and then the control torque of the slave robot is obtained by the torque controller according to the error between the current position of the slave robot and the expected position, and interacts with the environment; the torque controller is realized by anti-stepping control based on the Lyapunov stability criterion, and the control torque calculation formula of the master robot and the slave robot is as follows: Among them, τ m and τ s The control torque of the master robot and the slave robot; q m , and q s , The position and speed of the master robot and the slave robot; q md , and is the desired position, velocity, and acceleration of the master robot; q sd , and are the desired position, velocity, and acceleration of the slave robot; μ1, μ2, μ1′, and μ2′ are the control parameters of the master and slave robot controllers that are greater than zero; C m and C s Coriolis force and centripetal force matrices of the master robot and the slave robot; M m and M s Inertia matrices of the master and slave robots.

4. The solution for non-interruption human-machine workflow coupling based on variable virtual fixture according to claim 3 is characterized in that: In step S2, since the interaction force between the force applied by the operator and the real environment is measured by a force sensor, a corresponding dead zone is introduced. When the measured force is lower than a certain threshold, the force is regarded as zero, and the impedance characteristic parameter M of the environment is increased. e and C e .

5. The solution for non-interruption human-machine workflow coupling based on variable virtual fixture according to claim 1 is characterized in that: In step S3, in an actual laboratory human-machine collaborative workflow, a common operation is to use a pipette to extract a liquid sample from a running automated workflow, which is divided into two stages: an alignment stage of aligning the pipette with a specific test tube on a test tube rack and an insertion stage of inserting the pipette downward for subsequent operations. A variable-shape virtual fixture is designed for these two stages. The two variable shapes include: in the alignment stage, the working area is large and the position of the operation object is concentrated, and a funnel-shaped virtual fixture is used. The funnel-shaped virtual fixture limits the working area of ​​the slave robot to the range of the test tube rack; after selecting a specific test tube, the operator uses a button to change the virtual fixture into a cylindrical shape, which will be generated at the position of the selected test tube, while keeping the slave robot's working area consistent with the automated end of the movement, and limiting the direction of the tool at the end of the slave robot to remain aligned with the test tube.

6. The solution for non-interruption human-machine workflow coupling based on variable virtual fixture according to claim 5 is characterized in that: Depending on the task stage, the shape of the virtual fixture is switched. If it is the alignment stage, the virtual fixture is set to a funnel shape formed by a hyperboloid, and the posture constraint on the slave robot is not enabled; if it is the insertion stage, the virtual fixture is set to a cylindrical shape and the posture constraint is enabled.

7. The solution for non-interruption human-machine workflow coupling based on variable virtual fixture according to claim 1 is characterized in that: In step S4, the torque applied by the virtual fixture is calculated based on the geometric relationship of the virtual fixture, including: S41, Pose based on virtual fixture vf , is the center position Pos of the bottom circle of the funnel or cylinder vf (x vf ,y vf ,z vf ) and the normal vector n vf (n x ,n y ,n z ) to obtain the equation of the bottom plane: n x (xx vf )+n y (yy vf )+n z (zz vf )=0: Then it is converted into the form of Ax+By+Cz+D=0, where [A,B,C,D]=[n x ,n y ,n z ,-n x x vf -n y y vf -n z z vf ]; S42, calculate the current tool center position Pos of the robot tcp (x tcp ,y tcp ,z tcp ) and the distance from the bottom plane: S43, calculate the center point position of the plane in the virtual fixture where the slave robot is currently located: Pos c =Pos vf +d p n vf ; S44. Determine the radius of the current plane circle based on the shape of the virtual fixture: If it is a hyperbolic funnel, the radius is r c If it is cylindrical, the radius is the preset bottom radius r b , where k vf Determine the size of the funnel opening; S45. Calculate the force direction vector: forceVec=Pos c -Pos tcp ; S46. Calculate the force applied by the virtual fixture based on the spring damping model: F vf =K*forceVec-D*Vel tcp ; Among them, K and D are the spring damping coefficients of the virtual fixture, Vel tcp is the velocity of the tool center point.

8. The solution for non-interruption human-machine workflow coupling based on variable virtual fixture according to claim 7 is characterized in that: If the posture constraint is enabled, the current posture of the end tool of the slave robot and the set virtual fixture direction vector n are calculated. vf The clamp is then used to calculate the torque applied to the slave robot in the same way as step S46. The torque is combined with the force calculated in step S46 to obtain the Wrench vf ; Using the robot force Jacobian, we can calculate τ vf : τ vf =J T *Wrench vf ; Where J is the Jacobian matrix of the robot.

Images