Moon exploration mobile mechanical arm teleoperation method based on single-master-end self-adaptive switching

Abstract

The invention provides a lunar exploration mobile mechanical arm teleoperation method based on single-master-end self-adaptive switching. The lunar exploration mobile mechanical arm teleoperation method comprises the steps that a master-slave-end seven-degree-of-freedom redundant mechanical arm system and a corresponding kinematic model are built; hybrid asymmetric mapping models of the mobile platform and the mechanical arm are established respectively, and adaptive switching factors are designed to achieve adaptive switching between the mobile platform and the mechanical arm and adaptive switching between the mobile platform and the mechanical arm and between the mobile platform and the mechanical arm in a double-mapping mode; a force feedback model is established by fusing the switching factors, the virtual repulsive force in the moving process of the lunar rover and the virtual guiding force in the manipulating process of the mechanical arm are inspired and designed by an artificial potential field method, and meanwhile real tail end sensor measurement data are included. The invention provides an easier and more convenient single-master-end teleoperation mode integrating slave-end mobile platform and mechanical arm control for operators, the teleoperation efficiency and safety and the environment perception ability of the operators are improved, the workload of the operators is reduced, and the decision pressure of the operators is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of teleoperated robots, and in particular relates to a teleoperation method for a lunar exploration mobile mechanical arm based on single master end adaptive switching. Background Art

[0002] With the continuous advancement of lunar exploration technology, the sampling of lunar soil samples and the coordinated handling and assembly tasks proposed in the future construction of lunar scientific research stations have put forward higher requirements for lunar exploration robots. The mobile robotic arm can perform complex lunar soil drilling and sampling tasks with its high precision, strong stability and flexible operation capabilities. At the same time, during the construction of the lunar scientific research station, the mobile robotic arm can assist scientific researchers in deploying experimental equipment and building scientific research facilities, greatly improving construction efficiency and safety.

[0003] Nowadays, the autonomous capabilities of robots have been rapidly developed, but the limitations of their autonomous capabilities are still prominent in unstructured and complex environments, and it is difficult to completely replace humans to perform dangerous or difficult-to-reach tasks in the foreseeable future. The master-slave teleoperated robot system based on human-machine interaction is still a necessary way to solve this problem. In the master-slave teleoperated robot system, the master-slave heterogeneous system has attracted attention due to its flexibility and strong adaptability. Compared with the master-slave homogeneous system, the master-slave heterogeneous system allows the master and slave robots to differ in mechanical structure, size and number of joints, which greatly enriches the equipment selection and improves the practicality and application scope of the system. However, this heterogeneity also brings the complexity of motion mapping, especially in high-redundancy applications such as mobile robotic arms. The master-slave heterogeneous problem requires operators to make more efforts to coordinate the motion between the master and slave when performing tasks, which increases the workload and may affect the operation effect. Therefore, how to reduce the workload of operators has become the top priority of the study of master-slave heterogeneous systems. Summary of the invention

[0004] Purpose of the invention: The technical problem to be solved by the present invention is to provide a remote operation method for a lunar exploration mobile manipulator based on a single master-end adaptive switching in view of the deficiencies of the prior art. The method includes an asymmetric mapping model of the position and velocity of the six-wheel mobile platform of the lunar rover and a hybrid asymmetric mapping model of the position-velocity and position-position mapping of the manipulator, while considering the force feedback strategy of the adaptive switching of the slave-end mobile platform and the manipulator, providing the operator with a more relaxed and convenient single master-end remote operation mode integrating the manipulation of the slave-end mobile platform and the manipulator, reducing the workload of the operator and the decision-making pressure of the operator.

[0005] The specific implementation scheme of the present invention comprises the following steps:

[0006] Step 1, establishing a kinematic model of the master-slave robot, the master robot is specifically a master six-degree-of-freedom robot, the slave robot is specifically a slave lunar exploration mobile robotic arm, and the slave lunar exploration mobile robotic arm includes a slave lunar rover and a slave seven-degree-of-freedom redundant robotic arm;

[0007] Step 2: Establish an asymmetric mapping model of position and velocity for the slave lunar rover, establish a hybrid asymmetric mapping model including position and velocity and position and position mapping for the slave seven-degree-of-freedom redundant manipulator, and design an adaptive switching coefficient to realize the autonomous switching of the movement state, operation state and dual mapping mode of the slave seven-degree-of-freedom redundant manipulator;

[0008] Step 3, establish a force feedback model of the master-end six-degree-of-freedom robot. The force feedback received by the master-end six-degree-of-freedom robot includes the virtual repulsive force feedback of the slave-end lunar exploration mobile robotic arm in the moving state and the virtual guiding force or real contact force feedback in the operating state.

[0009] In step 1, the kinematic model of the master-end six-degree-of-freedom robot is specifically:

[0010]

[0011] (1)

[0012] Among them, the end position of the main end six-degree-of-freedom robot represents the calibrated position of the master-end six-degree-of-freedom robot, T represents the matrix transpose, where , , They represent the position vectors from the origin of the six-degree-of-freedom robot coordinate system to the end. Projection on the axis, The projection on the axis and Projection on axis; , , They are the first joint angle, the second joint angle, and the third joint angle of the six-degree-of-freedom robot at the master end; is the sum of the second joint angle and the third joint angle of the main end six-degree-of-freedom robot, that is ; and They are the position vectors from the origin to the end in the six-degree-of-freedom robot coordinate system of the master end. Projection on the plane and Projection on axis; and are the length of the first link and the length of the second link of the six-degree-of-freedom robot at the master end, respectively;

[0013] The master-end six-degree-of-freedom robot includes a six-degree-of-freedom robotic arm. The mapping modes all use the end position in the Cartesian coordinate system as input. The end position used is specifically the geometric center of the fourth joint of the robotic arm. Therefore, the kinematic modeling of the master-end six-degree-of-freedom robot only uses the first three joint angles. , , ;

[0014] The main computer on the main end six-degree-of-freedom robot collects the first three joint angles of the main end six-degree-of-freedom robot , , And according to formula (1), the end position of the six-degree-of-freedom robot at the master end is calculated ;

[0015] In step 1, the kinematic model of the slave lunar rover specifically includes:

[0016] Based on the Ackerman steering geometry, the forward speed of the rover from the end and the angular velocity The kinematic relationship with the ten joints of the slave lunar rover is as follows:

[0017]

[0018] (2)

[0019] The ten joints of the lunar rover are the steering joints of the four wheels at the front and rear ends and the driving joints of all six wheels. , , , They are respectively the angle of the left front wheel steering joint, the angle of the right front wheel steering joint, the angle of the left rear wheel steering joint, and the angle of the right rear wheel steering joint of the lunar rover from the end. , , , , , are respectively the angular velocity of the left front wheel, the angular velocity of the right front wheel, the angular velocity of the left middle wheel, the angular velocity of the right middle wheel, the angular velocity of the left rear wheel, and the angular velocity of the right rear wheel of the slave lunar rover; is half wheelbase; Half wheelbase; is the wheel radius;

[0020] According to formula (2), the slave computer carried by the slave lunar exploration mobile robotic arm will receive the forward speed from the master computer and the angular velocity Calculate the control instructions for the ten joints of the mobile platform and send them to the drive of the slave lunar rover;

[0021] In step 1, the kinematic model of the slave seven-DOF redundant manipulator is as follows:

[0022]

[0023]

[0024]

[0025] Among them, the end position of the redundant seven-degree-of-freedom robot arm from the end is the calibrated position of the end of the seven-DOF redundant manipulator from the slave end, where , , They represent the position vectors from the origin of the six-degree-of-freedom robot coordinate system to the end. Projection on the axis, The projection on the axis and Projection on the axis; Joint rotation angle of the seven-DOF redundant manipulator from the end is the joint rotation vector of the slave 7-DOF redundant manipulator, where , , , , , , They are the first joint angle, the second joint angle, the third joint angle, the fourth joint angle, the fifth joint angle, the sixth joint angle, and the seventh joint angle of the seven-degree-of-freedom redundant manipulator from the slave end; the nonlinear vector mapping function of the seven-degree-of-freedom redundant manipulator from the slave end The mapping relationship between the joint angle vector and the end position is established based on the DH method; the Jacobian of the redundant seven-degree-of-freedom manipulator from the end is the velocity Jacobian matrix based on the vector product method, for The Moore–Penrose generalized inverse matrix of ; is a constant positive definite gain matrix; the end velocity of the redundant manipulator with seven degrees of freedom from the slave end is In the robot arm position and speed mapping mode, it is directly obtained after solving the mapping mode. In the robot arm position and position mapping mode, it needs to be obtained by differentiating the time; the expected position of the end of the seven-degree-of-freedom redundant robot arm In the robot arm position and velocity mapping mode, it needs to be obtained by integrating the time. In the robot arm position and position mapping mode, it can be directly obtained after solving the mapping mode. The angular velocity of the joint of the redundant robot arm with seven degrees of freedom from the end The vector representing the angular velocity of each joint of the redundant manipulator with seven degrees of freedom from the end is the joint angle of the redundant manipulator with seven degrees of freedom from the end. The differential of .

[0026] In step 2, a mapping relationship between the joint angle vector and the end effector position is established based on the DH method. The asymmetric mapping model includes a position and velocity mapping mode of the slave rover. The hybrid asymmetric mapping model includes a manipulator position and velocity mapping mode and a position and position mapping mode, specifically including:

[0027] The position and velocity mapping mode of the slave lunar rover is expressed as:

[0028]

[0029]

[0030] Among them, the main end movement distance The current position of the master end six-degree-of-freedom robot and the initial zero position are Distance on the plane; rotation angle of the main end The current position of the main end six-degree-of-freedom robot and the initial zero position Angle of axis rotation; is the velocity vector of the lunar rover from the end, ; is the adaptive switching factor of the slave rover; the scale factor of the slave rover ,in , are constants related to velocity and angular velocity respectively; , The six-degree-of-freedom robot at the main end is The current and initial positions of the direction, , They are The current and initial positions of the direction; is a function that expands a vector into a diagonal matrix;

[0031] The master end six-degree-of-freedom robot coordinate system takes the geometric center of the first joint as the origin and the rotation axis of the first joint as Axis, vertically upward is the positive direction, when the first joint is at zero position, the rotation axis of the second joint is Axis, determined by the right-hand screw rule axis;

[0032] The vehicle coordinate system takes the geometric center of the lunar rover from the end as the origin and the forward direction as Axis, perpendicular to the surface of the lunar rover Axis, vertically upward is the positive direction, determined according to the right-hand screw rule axis;

[0033] The robot arm position and speed mapping mode is expressed as:

[0034]

[0035] in, , , , They are the seven-degree-of-freedom redundant manipulator coordinate systems at the end of the manipulator and at the slave end. , , The velocity component in the axial direction; is the adaptive switching factor of the redundant seven-degree-of-freedom manipulator from the slave end; ,in , , Respectively about , , The constant of the speed in the direction; the end position of the six-degree-of-freedom robot at the master end ,in , , They are the positions of the end of the robot arm in the seven-degree-of-freedom redundant robot arm coordinate system at the slave end. , , Projection in the axial direction;

[0036] The coordinate system of the slave 7-DOF redundant manipulator takes the geometric center of the plane connecting the manipulator and the vehicle body as the origin, and the rotation axis of the first joint of the manipulator is axis, and The axis direction is the same, determined according to the right-hand screw rule axis;

[0037] The robot arm position and position mapping mode are expressed as:

[0038]

[0039]

[0040] in, , , , They are the seven-degree-of-freedom redundant manipulator coordinate systems at the end of the manipulator and at the slave end. , , Position component in the axis direction; is a constant proportional factor, , , , They are , , Gain factors in three directions of the axis; is the end position of the slave-end seven-degree-of-freedom redundant robotic arm at the initial moment when the slave-end seven-degree-of-freedom redundant robotic arm switches to the position and position mapping mode; is the end position of the six-DOF robot at the master end at the initial moment when the seven-DOF redundant manipulator at the slave end switches to the position and position mapping mode, After the mapping mode is switched to the position-to-position mapping mode, the position of the end of the robot arm changes;

[0041] In the robot position and speed mapping mode, the slave computer will receive the expected speed of the end effector from the master computer. And the desired position of the end effector obtained by integration operation Analytically calculated as the joint angular velocity vector And send it to the joint drivers of the robot arm; in the robot arm position and position mapping mode, the slave computer will receive the expected position of the end effector from the master computer And the desired speed of the end effector obtained by differential operation Analytically calculated as the joint angular velocity vector And send it to the joint drivers of the robotic arm, so as to track the desired position of the end.

[0042] When the distance from the end effector of the seven-DOF redundant robot arm to the target object When the distance is greater than a certain value, the position and speed mapping mode is adopted to make the end of the robot arm quickly approach the target; when the distance When gradually decreasing, the position-to-position mapping mode is adopted to ensure the accuracy of task execution.

[0043] In step 2, the hybrid asymmetric mapping model is combined with the switching control strategy to design the following hybrid mapping mode weighted mapping:

[0044]

[0045] in, is a complex variable, is the switching factor, , Indicates about and A nonlinear function of is the distance between the slave 7-DOF redundant manipulator and the target; When it is reduced to 2cm to 5cm, Gradually decreases from 1 to 0, and the robot arm switches from position and speed mapping mode to position and position mapping mode.

[0046] In step 2, the motion state of the slave-end seven-degree-of-freedom redundant manipulator is switched by the adaptive switching coefficient, that is, the switching process of the movement state of the slave-end lunar rover and the operation state of the manipulator is controlled by the adaptive switching factor, which specifically includes:

[0047] Define the time-varying interval of the adaptive switching factor as the switching state, and record the distance between the slave rover and the target when entering the switching state as , the distances between the rover and the target when leaving the switching state are ; When the distance between the lunar rover and the target Greater than When the adaptive switching factor of the seven-DOF redundant manipulator from the slave end is , the weight factor of the forward motion state of the lunar rover from the end , the weight factor of the steering motion state of the lunar rover from the end , the slave end's seven-DOF redundant manipulator is in a moving state; when the distance between the slave end's lunar rover and the target Less than and greater than hour, gradually increases to 1, and , Gradually decreases to 0, the slave end seven-degree-of-freedom redundant manipulator gradually switches from the moving state of the slave end lunar rover to the manipulating state of the manipulator; when the distance between the slave end lunar rover and the target Less than At this time , , , the seven-degree-of-freedom redundant robotic arm from the slave end is in the manipulation state.

[0048] The forward motion state weight factor of the slave lunar rover , Steering motion state weight factor And the adaptive switching factor of the seven-degree-of-freedom redundant manipulator from the end Specifically:

[0049]

[0050] in, Indicates about , A nonlinear function of Indicates about , A nonlinear function of Indicates about The nonlinear function of .

[0051] The force feedback model of the master-end six-degree-of-freedom robot is established by inspiriting the artificial potential field method and integrating the real value measured by the end effector sensor. The virtual guidance force feedback of the slave-end mobile platform in the moving state is determined according to the distance between the slave-end mobile platform or robotic arm and the obstacles or targets in the environment. And virtual guidance force feedback of the robotic arm When the robot arm contacts the target, the force feedback of the robot arm is provided entirely by the force sensor measurements.

[0052] In step 3, the force feedback model of the master-end six-degree-of-freedom robot is:

[0053]

[0054] in, Feedback force of the main end; It is the virtual repulsive force feedback of the slave lunar rover in the moving state; Force feedback for a seven-DOF redundant robotic arm from the slave end.

[0055] In step 3, the virtual repulsive force feedback of the slave lunar rover in the moving state Specifically:

[0056]

[0057] in, is the distance vector from the obstacle to the rover, e is a natural constant, , is a positive real number.

[0058] The slave end seven degrees of freedom redundant manipulator force feedback Specifically:

[0059]

[0060]

[0061] in, is a piecewise function The right intersection point of the first two functions; is the distance vector from the target to the end effector; is the measurement value of the force sensor mounted on the end effector, , , is a positive real number.

[0062] The present invention also provides an electronic device, comprising a processor and a memory, wherein the memory stores program code, and when the program code is executed by the processor, the processor executes the steps of the described method.

[0063] The beneficial effects of the present invention are as follows: 1. The asymmetric mapping model of the position and speed of the six-wheel mobile platform of the lunar rover and the hybrid asymmetric mapping model of the manipulator including position-speed and position-position mapping designed by the present invention take advantage of the slave mobile manipulator to map the limited workspace of the master end to the unlimited workspace of the slave end, and realize automatic switching in multiple mapping modes;

[0064] 2. Compared with the traditional master-slave heterogeneous teleoperated robot position and speed switching mode, the weighted mapping of the hybrid mapping mode of the manipulator designed in the present invention does not require manual switching, and the movement continuity can be guaranteed;

[0065] 3. The force feedback model based on single-master-end adaptive switching designed by the present invention has good adaptability to complex and unstructured environments, can improve the operator's perception of the environment, and provide guidance for the operator.

[0066] In summary, the present invention applies a single-master-end adaptive switching method to the remote operation of the lunar exploration mobile robotic arm, providing operators with a more relaxed and convenient single-master-end remote operation method that integrates the slave-end mobile platform and robotic arm manipulation, thereby improving the efficiency and safety of remote operation and the operator's environmental perception ability, reducing the operator's workload and reducing the operator's decision-making pressure. BRIEF DESCRIPTION OF THE DRAWINGS

[0067] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments, and the above and / or other advantages of the present invention will become more clear.

[0068] Figure 1 It is a connection diagram of the master-slave heterogeneous teleoperated robot of the present invention.

[0069] Figure 2 It is a schematic diagram of the Ackermann steering geometry of a mobile platform.

[0070] Figure 3 This is a schematic diagram of the joint positions and rotation directions of the seven-degree-of-freedom redundant robotic arm at the slave end.

[0071] Figure 4 It is a schematic diagram of the coordinate system of the six-degree-of-freedom robot on the master end.

[0072] Figure 5 This is a schematic diagram of the lunar rover's body coordinate system from the slave end.

[0073] Figure 6 It is a schematic diagram of the robot arm coordinate system. DETAILED DESCRIPTION

[0074] This embodiment provides a remote operation method for a lunar exploration mobile manipulator based on single master-end adaptive switching. In the embodiment, a remote operation system platform is used. The master-end six-degree-of-freedom robot uses a Phantom Omni force feedback device, the slave end uses a Luoshi xMate ER7 Pro, and the network connection uses a local area network formed by a router. The software platform is based on the open source robot operating system ROS, and the algorithm is implemented using Visual Studio Code software.

[0075] The master-end six-degree-of-freedom robot is specifically the master-end six-degree-of-freedom robotic arm; the slave-end seven-degree-of-freedom redundant robotic arm includes the slave-end lunar rover and the slave-end seven-degree-of-freedom redundant robotic arm. The base of the slave-end seven-degree-of-freedom redundant robotic arm is installed at the front end of the slave-end lunar rover. The end of the slave-end seven-degree-of-freedom redundant robotic arm is installed with an end effector and equipped with a force sensor, and the front end of the mobile platform is installed with a laser radar; the master-end computer and the slave-end computer communicate wirelessly through the ROS topic mechanism, and the slave-end computer is connected to the slave-end lunar rover, the seven-degree-of-freedom redundant robotic arm, the force sensor and the laser radar. Figure 1 As shown in the figure, the master computer collects the joint angles of the end of the master six-degree-of-freedom robot and performs analytical calculations and mapping calculations, and then sends the control signal to the slave computer to control the speed or position of the slave robot. At the same time, the slave computer collects the force sensor information at the end of the robot arm, calculates the virtual force and feeds it back to the master computer.

[0076] The lunar exploration mobile manipulator teleoperation method based on single master end adaptive switching provided in this embodiment includes the following steps:

[0077] Step 1: Establish the kinematic models of the master and slave robots, including the kinematic models of the master six-degree-of-freedom robot, the slave lunar rover, and the seven-degree-of-freedom redundant robotic arm;

[0078] The end position of the master end six degrees of freedom robot , , The details are as follows:

[0079]

[0080]

[0081] In the embodiment of the present invention, the main end six-degree-of-freedom robot adopts a six-degree-of-freedom robotic arm, and the mapping mode uses the end position in the Cartesian coordinate system as input. The end position used is specifically the geometric center of the fourth joint of the robotic arm. Therefore, the kinematic modeling of the main end six-degree-of-freedom robot only uses the first three joint angles. The main end computer collects the first three joint angles of the main end six-degree-of-freedom robot. , , And according to the above kinematic relationship, the end position of the master end six-degree-of-freedom robot is analytically calculated.

[0082] like Figure 2 As shown, based on the Ackerman steering geometry, the forward speed of the lunar rover from the end and the angular velocity The kinematic relationship between its ten joints is as follows:

[0083]

[0084]

[0085] Through the above inverse kinematics relationship, the slave computer receives the forward speed of the mobile platform from the master computer. and the angular velocity The control instructions for the ten joints of the mobile platform are analyzed and calculated and sent to the driver of the mobile platform.

[0086] The kinematic model of the slave seven-DOF redundant manipulator is as follows:

[0087]

[0088]

[0089]

[0090] The joints of the robotic arm are as follows Figure 3 As shown, the velocity Jacobian matrix is ​​established based on the vector product method , based on the D and H method, the mapping relationship between the joint angle vector and the end effector position is established. In the robot position and speed mapping mode, the slave computer receives the expected end effector speed from the master computer. And the desired position of the end effector obtained by integration operation Analytically calculated as the joint angular velocity vector And send it to the joint drivers of the robot arm; in the robot arm position and position mapping mode, the slave computer will receive the expected position of the end effector from the master computer And the desired speed of the end effector obtained by differential operation Analytically calculated as the joint angular velocity vector And send it to the joint drivers of the robotic arm, so as to track the desired position of the end.

[0091] Step 2: Establish an asymmetric mapping model of position and speed for the six-wheel mobile platform of the lunar rover, establish a hybrid asymmetric mapping model including position-speed and position-position mapping for the robotic arm, and design an adaptive switching coefficient to realize the autonomous switching of the mobile state and operation state of the lunar exploration mobile robotic arm and the dual mapping mode of the robotic arm;

[0092] The two established asymmetric mapping models contain three mapping modes, as follows:

[0093] a) Slave rover position and velocity mapping mode:

[0094]

[0095]

[0096] In the embodiment of the present invention, the coordinate system of the master end six-degree-of-freedom robot is as follows: Figure 4 As shown, the body coordinate system of the slave mobile platform is as follows Figure 5 The host computer obtains the end position of the six-degree-of-freedom robot based on the above kinematic model and further converts it into and , and then calculate the speed of the slave mobile platform according to the above mapping relationship and send it to the slave computer.

[0097] b) Robot position and speed mapping mode:

[0098]

[0099] In the embodiment of the present invention, the seven-degree-of-freedom redundant manipulator coordinate system from the slave end is as follows: Figure 6 After the master computer obtains the end position of the robot according to the kinematic model of the master-end six-degree-of-freedom robot, it calculates the end speed of the slave-end seven-degree-of-freedom redundant robot arm according to the above mapping relationship and sends it to the slave-end computer.

[0100] c) Robotic arm position and position mapping mode:

[0101]

[0102]

[0103] Among them, in order to meet the requirements of fine operation, It should not be set too large; when the slave 7-DOF redundant robot arm switches to the position-to-position mapping mode, the slave computer collects the joint angles of the slave 7-DOF redundant robot arm and obtains the end position of the slave 7-DOF redundant robot arm at the initial moment of switching based on the positive kinematics of the slave 7-DOF redundant robot arm. The master computer collects the first three joint angles of the master robot and obtains the end position of the master robot at the initial switching moment according to the kinematic model of the master robot The master computer calculates the expected position of the end of the slave seven-DOF redundant robot arm based on the above mapping relationship and sends it to the slave computer.

[0104] When the distance from the end effector of the seven-DOF redundant robot arm to the target object When the distance is greater than a certain value, the position and speed mapping mode is adopted to make the end of the robot arm quickly approach the target; when the distance When gradually decreasing, the position-to-position mapping mode is adopted to ensure the accuracy of task execution. The specific weighted mapping mode is:

[0105]

[0106] Due to the requirement of fine operation, the characteristic distance between the two mapping modes of the robot arm is small, so the switching factor The design must ensure that the mapping mode can be quickly switched within a short distance range to avoid premature collision with the target.

[0107] The switching between the rover and the robotic arm mapping modes on the slave side depends on the adaptive switching factor , and The implementation is as follows:

[0108]

[0109] The distance between the rover and the target when entering and leaving the switching state , It is determined by the working space of the robot arm and the specific mission payload to ensure that the robot arm is in the appropriate position when it reaches the target.

[0110] Step 3: Establish a force feedback model of the master-end six-degree-of-freedom robot. The force feedback received by the master-end six-degree-of-freedom robot includes the virtual repulsive force feedback of the slave-end seven-degree-of-freedom redundant robotic arm in the moving state and the virtual guiding force / real contact force feedback in the operating state.

[0111] The force feedback model of the master-end six-degree-of-freedom robot is as follows:

[0112]

[0113] The virtual repulsive force feedback from the end lunar rover in the moving state The details are as follows:

[0114]

[0115] Force feedback from a seven-degree-of-freedom redundant manipulator The details are as follows:

[0116]

[0117]

[0118] Among them, by adjusting It can change the operator's perception of obstacles. The larger the value, the greater the repulsive force felt near the obstacle, and the smaller the repulsive force felt far away, thus ensuring sensitive perception when the obstacle is close, and reducing perception of it when the distance is far away to avoid interference; Defines the radius of the near side of the obstacle. , Change the feedback force when the operator performs fine terminal operations to avoid excessive feedback force causing inconvenience to fine operations.

[0119] The single-master-end adaptive switching remote control technology proposed in the present invention can improve the control efficiency by about 30% compared with the widely used "move-wait" ground remote control mode, and greatly improve the control experience and reduce the decision-making burden of the operator.

[0120] The present invention provides a remote operation method for a lunar exploration mobile manipulator based on single-master-end adaptive switching. There are many methods and ways to implement the technical solution. The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the protection scope of the present invention. All components not specified in this embodiment can be implemented by existing technologies.

Claims

1. A lunar exploration mobile manipulator teleoperation method based on single master-end adaptive switching, characterized in that: The following steps are involved: Step 1, establishing a kinematic model of the master-slave robot, the master robot is specifically a master six-degree-of-freedom robot, the slave robot is specifically a slave lunar exploration mobile robotic arm, and the slave lunar exploration mobile robotic arm includes a slave lunar rover and a slave seven-degree-of-freedom redundant robotic arm; Step 2: Establish an asymmetric mapping model of position and velocity for the slave lunar rover, establish a hybrid asymmetric mapping model including position and velocity and position and position mapping for the slave seven-degree-of-freedom redundant manipulator, and design an adaptive switching coefficient to realize the autonomous switching of the movement state, operation state and dual mapping mode of the slave seven-degree-of-freedom redundant manipulator; Step 3, establish a force feedback model of the master-end six-degree-of-freedom robot. The force feedback received by the master-end six-degree-of-freedom robot includes the virtual repulsive force feedback of the slave-end lunar exploration mobile robotic arm in the moving state and the virtual guiding force or real contact force feedback in the operating state.

2. The method according to claim 1, characterized in that In step 1, the kinematic model of the master-end six-degree-of-freedom robot is specifically: （1） Among them, the end position of the main end six-degree-of-freedom robot represents the calibrated position of the master-end six-degree-of-freedom robot, T represents the matrix transpose, where , , They represent the position vectors from the origin of the six-degree-of-freedom robot coordinate system to the end. Projection on the axis, The projection on the axis and Projection on axis; , , They are the first joint angle, the second joint angle, and the third joint angle of the six-degree-of-freedom robot at the master end; is the sum of the second joint angle and the third joint angle of the main end six-degree-of-freedom robot, that is ; and They are the position vectors from the origin to the end in the six-degree-of-freedom robot coordinate system of the master end. Projection on the plane and Projection on axis; and are the length of the first link and the length of the second link of the six-degree-of-freedom robot at the master end, respectively; The master-end six-degree-of-freedom robot includes a six-degree-of-freedom robotic arm. The mapping modes all use the end position in the Cartesian coordinate system as input. The end position used is specifically the geometric center of the fourth joint of the robotic arm. Therefore, the kinematic modeling of the master-end six-degree-of-freedom robot only uses the first three joint angles. , , ; The main computer on the main end six-degree-of-freedom robot collects the first three joint angles of the main end six-degree-of-freedom robot , , And according to formula (1), the end position of the six-degree-of-freedom robot at the master end is calculated ; In step 1, the kinematic model of the slave lunar rover specifically includes: Based on the Ackerman steering geometry, the forward speed of the rover from the end and the angular velocity The kinematic relationship with the ten joints of the slave lunar rover is as follows: （2） The ten joints of the lunar rover are the steering joints of the four wheels at the front and rear ends and the driving joints of all six wheels. , , , They are respectively the angle of the left front wheel steering joint, the angle of the right front wheel steering joint, the angle of the left rear wheel steering joint, and the angle of the right rear wheel steering joint of the lunar rover from the end. , , , , , are respectively the angular velocity of the left front wheel, the angular velocity of the right front wheel, the angular velocity of the left middle wheel, the angular velocity of the right middle wheel, the angular velocity of the left rear wheel, and the angular velocity of the right rear wheel of the slave lunar rover; is half wheelbase; Half wheelbase; is the wheel radius; According to formula (2), the slave computer carried by the slave lunar exploration mobile robotic arm will receive the forward speed from the master computer and the angular velocity Calculate the control instructions for the ten joints of the mobile platform and send them to the drive of the slave lunar rover; In step 1, the kinematic model of the slave seven-DOF redundant manipulator is as follows: Among them, the end position of the redundant seven-degree-of-freedom robot arm from the end is the calibrated position of the end of the seven-DOF redundant manipulator from the slave end, where , , They represent the position vectors from the origin of the six-degree-of-freedom robot coordinate system to the end. Projection on the axis, The projection on the axis and Projection on the axis; Joint rotation angle of the seven-DOF redundant manipulator from the end is the joint rotation vector of the slave 7-DOF redundant manipulator, where , , , , , , They are the first joint angle, the second joint angle, the third joint angle, the fourth joint angle, the fifth joint angle, the sixth joint angle, and the seventh joint angle of the seven-degree-of-freedom redundant manipulator from the slave end; the nonlinear vector mapping function of the seven-degree-of-freedom redundant manipulator from the slave end The mapping relationship between the joint angle vector and the end position is established based on the DH method; the Jacobian of the redundant seven-degree-of-freedom manipulator from the end is the velocity Jacobian matrix based on the vector product method, for The Moore–Penrose generalized inverse matrix of ; is a constant positive definite gain matrix; the end velocity of the redundant manipulator with seven degrees of freedom from the slave end is In the robot arm position and speed mapping mode, it is directly obtained after solving the mapping mode. In the robot arm position and position mapping mode, it needs to be obtained by differentiating the time; the expected position of the end of the seven-degree-of-freedom redundant robot arm In the robot arm position and velocity mapping mode, it needs to be obtained by integrating the time. In the robot arm position and position mapping mode, it can be directly obtained after solving the mapping mode. The angular velocity of the joint of the redundant robot arm with seven degrees of freedom from the end The vector representing the angular velocity of each joint of the redundant manipulator with seven degrees of freedom from the end is the joint angle of the redundant manipulator with seven degrees of freedom from the end. The differential of .

3. The method according to claim 2, characterized in that In step 2, a mapping relationship between the joint angle vector and the end effector position is established based on the DH method. The asymmetric mapping model includes a position and velocity mapping mode of the slave rover. The hybrid asymmetric mapping model includes a manipulator position and velocity mapping mode and a position and position mapping mode, specifically including: The position and velocity mapping mode of the slave lunar rover is expressed as: Among them, the main end movement distance The current position of the master end six-degree-of-freedom robot and the initial zero position are Distance on the plane; rotation angle of the main end The current position of the main end six-degree-of-freedom robot and the initial zero position Angle of axis rotation; is the velocity vector of the lunar rover from the end, ; is the adaptive switching factor of the slave rover; the scale factor of the slave rover ,in , are constants related to velocity and angular velocity respectively; , The six-degree-of-freedom robot at the main end is The current and initial positions of the direction, , They are The current and initial positions of the direction; The master end six-degree-of-freedom robot coordinate system takes the geometric center of the first joint as the origin and the rotation axis of the first joint as Axis, vertically upward is the positive direction, when the first joint is at zero position, the rotation axis of the second joint is Axis, determined by the right-hand screw rule axis; The vehicle coordinate system takes the geometric center of the lunar rover from the end as the origin and the forward direction as Axis, perpendicular to the surface of the lunar rover Axis, vertically upward is the positive direction, determined according to the right-hand screw rule axis; The robot arm position and speed mapping mode is expressed as: in, , , , They are the seven-degree-of-freedom redundant manipulator coordinate systems at the end of the manipulator and at the slave end. , , The velocity component in the axial direction; is the adaptive switching factor of the redundant seven-degree-of-freedom manipulator from the slave end; ,in , , Respectively about , , The constant of the speed in the direction; the end position of the six-degree-of-freedom robot at the master end ,in , , They are the positions of the end of the robot arm in the seven-degree-of-freedom redundant robot arm coordinate system at the slave end. , , Projection in the axial direction; The coordinate system of the slave 7-DOF redundant manipulator takes the geometric center of the plane connecting the manipulator and the vehicle body as the origin, and the rotation axis of the first joint of the manipulator is axis, and The axis direction is the same, determined according to the right-hand screw rule axis; The robot arm position and position mapping mode are expressed as: in, , , , They are the seven-degree-of-freedom redundant manipulator coordinate systems at the end of the manipulator and at the slave end. , , Position component in the axis direction; is a constant proportional factor, , , , They are , , Gain factors in three directions of the axis; is the end position of the slave-end seven-degree-of-freedom redundant robotic arm at the initial moment when the slave-end seven-degree-of-freedom redundant robotic arm switches to the position and position mapping mode; is the end position of the six-DOF robot at the master end at the initial moment when the seven-DOF redundant manipulator at the slave end switches to the position and position mapping mode, After the mapping mode is switched to the position-to-position mapping mode, the end position of the robot arm changes; In the robot position and speed mapping mode, the slave computer will receive the expected speed of the end effector from the master computer. And the desired position of the end effector obtained by integration operation Analytically calculated as the joint angular velocity vector And send it to the joint drivers of the robot arm; in the robot arm position and position mapping mode, the slave computer will receive the expected position of the end effector from the master computer And the desired speed of the end effector obtained by differential operation Analytically calculated as the joint angular velocity vector And send it to the joint drivers of the robotic arm, so as to track the desired position of the end.

4. The method according to claim 3, characterized in that: In step 2, the hybrid asymmetric mapping model is combined with the switching control strategy to design the following hybrid mapping mode weighted mapping: in, is a complex variable, is the switching factor, , Indicates about and A nonlinear function of is the distance between the slave 7-DOF redundant manipulator and the target; When it is reduced to 2cm to 5cm, Gradually decreases from 1 to 0, and the robot arm switches from position and speed mapping mode to position and position mapping mode.

5. The method according to claim 4, characterized in that In step 2, the motion state of the slave-end seven-degree-of-freedom redundant manipulator is switched by the adaptive switching coefficient, that is, the switching process of the movement state of the slave-end lunar rover and the operation state of the manipulator is controlled by the adaptive switching factor, which specifically includes: Define the time-varying interval of the adaptive switching factor as the switching state, and record the distance between the slave rover and the target when entering the switching state as , the distances between the rover and the target when leaving the switching state are ; When the distance between the rover and the target Greater than When the adaptive switching factor of the seven-DOF redundant manipulator from the slave end is , the weight factor of the forward motion state of the lunar rover from the end , the weight factor of the steering motion state of the lunar rover from the end , the slave end's seven-DOF redundant manipulator is in a moving state; when the distance between the slave end's lunar rover and the target Less than and greater than hour, gradually increases to 1, and , Gradually decreases to 0, the slave end seven-degree-of-freedom redundant manipulator gradually switches from the moving state of the slave end lunar rover to the manipulating state of the manipulator; when the distance between the slave end lunar rover and the target Less than At this time , , , the seven-degree-of-freedom redundant robotic arm from the slave end is in the manipulation state.

6. The method according to claim 5, characterized in that The forward motion state weight factor of the slave lunar rover , Steering motion state weight factor And the adaptive switching factor of the seven-degree-of-freedom redundant manipulator from the end Specifically: in, Indicates about , A nonlinear function of Indicates about , A nonlinear function of Indicates about Non-linear function.

7. The method according to claim 6, characterized in that In step 3, the force feedback model of the master-end six-degree-of-freedom robot is: in, Feedback force of the main end; It is the virtual repulsive force feedback of the slave lunar rover in the moving state; Force feedback for a seven-DOF redundant robotic arm from the slave end.

8. The method according to claim 7, characterized in that In step 3, the virtual repulsive force feedback of the slave lunar rover in the moving state Specifically: in, is the distance vector from the obstacle to the rover, e is a natural constant, , is a positive real number.

9. The method according to claim 8, characterized in that The slave end seven degrees of freedom redundant manipulator force feedback Specifically: in, is a piecewise function The right intersection point of the first two functions; is the distance vector from the target to the end effector; is the measurement value of the force sensor mounted on the end effector, , , is a positive real number.

10. An electronic device, characterized in that: The method comprises a processor and a memory, wherein the memory stores program codes, and when the program codes are executed by the processor, the processor executes the steps of the method according to any one of claims 1 to 9.

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