A solution to non-interruption human-machine workflow coupling based on variable virtual fixtures

Abstract

The present invention discloses a solution for non-interruption human-machine workflow coupling based on a variable virtual fixture, which belongs to the field of human-machine interaction technology, including S1, dividing the workflow in the laboratory into manual operation workflow and automated workflow; 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 with a variable shape; S4, calculating the torque applied by the virtual fixture; S5, introducing the torque of the virtual fixture into the teleoperation system to achieve non-interference coupling in the human-machine workflow; the solution for non-interruption human-machine workflow coupling based on a variable virtual fixture provided by the present invention achieves the addition of manual operation workflow without interfering with or interrupting the automated workflow, while avoiding contact between humans and harmful environments, thereby ensuring good human-machine interaction performance and safety of the system.

Description

Technical Field

[0001] The present 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 typically possess greater flexibility and intelligence, capable of interacting with humans through perception and learning. However, existing Cobots still face numerous challenges in complex and dynamic working environments, particularly those requiring highly flexible human-robot interaction. These challenges include ensuring operational continuity, seamless workflows, and the safety of human-robot collaboration. Experimental processes in biomedical laboratories are often highly complex and dynamic, involving extensive manual operations and real-time intervention. This places higher demands on existing automated robotic systems, and most existing automated laboratories focus on fully automated workflows. For prior art, see patents with publication numbers CN202411365422.9 and CN202420609105.6. These patents focus on developing automated workflows, such as precise positioning and sample handling, but do not consider workflows requiring human intervention. Once a human is involved in the workflow, automated tasks are disrupted.

[0003] A virtual fixture is a computer-generated auxiliary device that provides constraints, guidance, or assistance during robotic operations through software algorithms, simulating the functions of an actual physical fixture. Prior art has proposed a solution for performing 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 enable conversion between different virtual fixtures in the drilling and alignment stages. The human-computer interaction workflow in the laboratory is relatively standardized relative to the surgical process, such as using a pipette to inject liquid into a test tube in an automated workflow, or removing 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. Furthermore, the computing power required for machine learning is high and 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 objectives, 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. Calculate the control torque of the master robot and the slave robot in the teleoperation system, and transmit 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 shape-shifting virtual fixture, whose pose is updated according to the movement of the object being manipulated in the automated workflow and whose shape is determined according to the stage of the operation, for applying a guiding force to the operator manipulating 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 characteristics Determine the desired master robot motion, where q md 、 and They represent the expected position, velocity, and acceleration of the master robot in the joint space, respectively. m and 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 by the torque controller according to the error between the current position and the desired position of the master robot; due to the influence of communication, the position information transmitted to the slave robot contains high-frequency noise, which is first passed through a low-pass filter to obtain the desired motion of the slave robot, and then the control torque of the slave robot at this time is obtained by the torque controller according to the error between the current position and the desired position of the slave robot, and interacts with the environment; wherein the torque controller is implemented 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:

[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 The inertia matrix of the master robot and the slave robot.

[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, when the working area is large and the position of the operation object is relatively concentrated, 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, making it 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, 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 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.

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

[0019] S41, Pose based on virtual fixture vf , that is, the center position of the funnel or cylinder bottom circle 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, then 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-damper 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 torque applied to the slave robot is calculated by the same method as step S46, and the torque is combined with the force calculated in step S46 to obtain 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 by a teleoperation control framework, and by introducing a shape-shifting virtual fixture technology, the manual operation workflow is integrated without interfering with the existing automated workflow, thus realizing an uninterrupted human-machine workflow coupling system. This 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, adapting to the highly complex and dynamically changing operational requirements in biomedical laboratories. This enables the robotic system to respond flexibly in diverse 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 a solution to the non-interruption human-machine workflow coupling based on a variable virtual fixture according to the present invention;

[0043] Figure 2 Schematic diagram of the funnel-shaped virtual fixture in the alignment stage of the present invention;

[0044] Figure 3 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 as claimed, but rather merely represents selected embodiments of the invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without inventive effort shall fall 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 1As shown, it includes a master robot and a slave robot; under the influence of the external torque exerted 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 master robot in the joint space, respectively. m and 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. Based on the error between the current and desired positions of the master robot, the torque controller is used to determine the control torque for the master robot. Due to communication, the position information transmitted to the slave robot contains high-frequency noise. This information is first passed through a low-pass filter to determine the desired motion of the slave robot. Based on the error between the current and desired positions of the slave robot, the torque controller is used to determine the control torque for the slave robot and interact with the environment. The torque controller is implemented using backstepping control based on the Lyapunov stability criterion. The control torques of the master and slave robots are calculated 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 sThe inertia matrix of the master robot and the slave robot.

[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 actual laboratory human-machine collaborative workflows, a common operation is to use a pipette to extract a liquid sample from an ongoing automated workflow. In this embodiment, this is used as an example 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. At the same time, the position and posture of the virtual fixture will be updated as the object being operated in the automated workflow moves, 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 large 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 with the required liquid extraction 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, it limits the direction of the tool at the end of the slave robot 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, ensuring 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 Pose vf , that is, the center position of the funnel or cylinder bottom circle Pos vf and normal vector n vf, which can be dynamically adjusted 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 pre-calibrating the coordinate system of the automation end and the coordinate system of the robot in the interactive end teleoperation system. 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 The size of the required workspace can be determined by the user, such as the radius of the test tube or the radius of the test tube rack section. The shape of the virtual fixture can be switched according to the different task stages. For example, in the alignment stage, the virtual fixture is set to a funnel shape formed by a hyperboloid, and the posture constraints on the slave robot are not enabled. In the insertion stage, the virtual fixture is set to a cylindrical shape, and the posture constraints are enabled. The calculation process is as follows:

[0056] S41, Pose based on virtual fixture vf , that is, the center position of the funnel or cylinder bottom circle 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, then 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-damper 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 calculated using the same method as in step S46 to apply a torque to the slave robot; this 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, and so on. Simply replace the corresponding geometric shape when calculating the force vector. However, to accommodate the practical application of this embodiment, the virtual fixture in this invention uses two shapes: a funnel 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 provides the operator with guidance synchronized with the automated workflow motion.

[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 workflows into the system without interfering with and interrupting various existing laboratory automation workflows. At the same time, the system can avoid direct contact between the operator and the harmful environment, ensuring that the system has excellent human-machine interaction performance and high safety. The operator controls the master robot through the remote operation terminal while being away from the harmful environment, thereby commanding the slave robot to perform specific operations and interacting collaboratively 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, thereby achieving continuity and smoothness of human-machine collaboration without interfering with the existing automated workflow. The control algorithm adopted by the system has a low computational burden, which ensures its universality and real-time performance in various laboratory environments and can adapt to diverse operational needs.

[0078] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit the same. 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 solutions of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A solution for non-interruption human-machine workflow coupling based on variable virtual fixtures, characterized by: 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 master robot and slave robot; S2. Calculate the control torque of the master robot and the slave robot in the teleoperation system, and transmit 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 shape-shifting virtual fixture, whose pose is updated according to the movement of the object being manipulated in the automated workflow and whose shape is determined according to the stage of the operation, for applying a guiding force to the operator manipulating 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; In step S2, the control torque of the master robot is obtained by the torque controller based on the error between the current position of the master robot and the desired position. Due to the influence of communication, the position information transmitted to the slave robot contains high-frequency noise. The desired motion of the slave robot is first obtained by passing it through a low-pass filter. Then, the control torque of the slave robot is obtained by the torque controller based on the error between the current position of the slave robot and the desired position, and the control torque is interacted with the environment. The torque controller is implemented 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: 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 The inertia matrix of the master robot and the slave robot; 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: the alignment stage of aligning the pipette with a specific test tube on the test tube rack and the 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.

2. The solution for non-interruption human-machine workflow coupling based on variable virtual fixtures according to claim 1 is characterized in that: In step S1, 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 master robot in the joint space, respectively. m and 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 a variable virtual fixture according to claim 1 is characterized by: In step S2, since the interaction force between the force applied by the operator and the real environment is measured by the 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 .

4. The solution for non-interruption human-machine workflow coupling based on a variable virtual fixture according to claim 1 is characterized by: 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 of 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.

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 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, then 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-damper 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.

6. The solution for non-interruption human-machine workflow coupling based on a variable virtual fixture according to claim 5 is characterized by: 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 torque applied to the slave robot is calculated by the same method as step S46, and the torque is combined with the force calculated in step S46 to obtain Wrench vf ; Calculate τ using the robot force Jacobi vf : τ vf =J T *Wrench vf ; Where J is the Jacobian matrix of the robot.

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