Man-machine cooperative teleoperation control method and device based on main power guidance

Abstract

The invention discloses a man-machine cooperative teleoperation control method and device based on main power guidance. According to the invention, the event trigger signal is output through the resettable pedal plate and is used for controlling the event trigger state, the mapping establishment and cancellation of the master-slave terminal equipment are controlled according to the event trigger state, and an operator realizes master-slave teleoperation control through hand-foot coordination; through the improved artificial potential field, the guiding force of the slave end equipment is mapped to the master end operation equipment, and the main power compliant guiding man-machine cooperation teleoperation control is realized by taking compliant interaction between the force feedback equipment and an operator as guidance. According to the method, the problem that the master and slave working spaces are not matched in the teleoperation process is solved, a guiding force potential field is established by taking a slave end target position track as guidance, guiding force is mapped to a master end controller, a guiding force model is improved to realize active force compliant guiding, and by combining the decision-making ability of a person and the control ability of a mechanical arm, flexible guiding of the main force is realized. Man-machine cooperative teleoperation control is realized, and high efficiency, intuition and stability of teleoperation are ensured.

Description

Technical Field

[0001] The invention relates to a human-machine collaborative teleoperation control method in the field of teleoperated robots, and in particular to a human-machine collaborative teleoperation control method and device based on active force guidance. Background Art

[0002] At present, on the one hand, with the continuous development of intelligent manufacturing technology, robots have shown great development potential in the industrial field, especially in high-risk environments, more and more robots are beginning to replace manual remote operations, ensuring the safety of workers themselves; on the other hand, facing scenes such as industrial assembly with high precision and heavy weight requirements, compared with traditional manual operations, robots have unique advantages and can better perform assembly and debugging tasks. Teleoperation technology establishes a posture mapping relationship between the operator and the robot, accurately maps the position and posture of the operator to the robot, and realizes the operator's remote operation of the robot to perform tooling tasks.

[0003] However, most current teleoperation systems have common defects such as mismatch between master and slave workspaces, low operating efficiency, and unintuitive operation, which pose challenges to their widespread application in the industrial field.

[0004] Therefore, it is urgent to design a control method to improve the efficiency of teleoperation through human-machine collaborative control. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides a human-machine collaborative teleoperation control method and device based on active force guidance. Firstly, the present invention aims at the problem of mismatch between the master and slave postures of teleoperation, and introduces a pedal to change the output of the enable signal in the teleoperation system, determines the event trigger state, controls the start and stop of the master-slave posture mapping, and realizes the accurate mapping of the master-end device workspace to each task subspace of the slave end; secondly, in view of the problem of low efficiency of teleoperation operation, the traditional artificial potential field method model is improved, and a compliant artificial force field control method is proposed, which is based on the ideal trajectory of the slave end target, and the artificial force field of the slave end device is mapped to the force guidance link of the master end in the teleoperation system to achieve efficient and accurate teleoperation trajectory guidance. Under the guidance of the compliant force of the master end, the operator can control the master end device to move along the main path direction of the guidance, and can have a certain motion mapping ability in the direction of the deviation path, combining the flexible decision-making ability of people with the control accuracy of robots, solving the problem of low efficiency in teleoperation, and meeting the operation requirements in special and high-risk environments. It is safe, efficient, practical, and has good market application prospects.

[0006] The technical solution adopted by the present invention is:

[0007] 1. A human-machine collaborative teleoperation control method based on active force guidance

[0008] Step 1: Construct the guiding force potential field of the slave end according to the ideal trajectory of the slave end manipulator;

[0009] Step 2: Install a resettable foot pedal at the master end and use the resettable foot pedal as an event trigger switch to control the mapping of master and slave end devices and the establishment and cancellation of active power guidance according to the event trigger status, so as to realize remote operation control by the operator.

[0010] In step 1, the guiding force potential field of the slave end satisfies the following formula:

[0011]

[0012] ρ=ρ(q,q g )

[0013] Among them, U att (q) represents the guiding force potential field, ρ is the distance between the moving point q and the target point q in the potential field g The vector between two points, ρ() represents the vector calculation function between two points, ρ m is the distance between the moving point and the target point in the initial state, η is the gain coefficient;

[0014] The step 2 is specifically as follows:

[0015] If the resettable foot pedal is not triggered, the slave-end robotic arm is in a stationary state; if the resettable foot pedal is triggered, the position and posture of the teleoperation master hand of the master end and the slave-end robotic arm are obtained, the position and posture of the teleoperation master hand of the master end is mapped to the slave-end robotic arm and the position and posture of the slave-end robotic arm is updated, thereby realizing teleoperation control under human-machine collaboration; and the guiding force of the slave-end robotic arm is calculated according to the position of the slave-end robotic arm and the guiding force is mapped to the teleoperation master hand of the master end, thereby completing human-machine collaborative teleoperation control under the guidance of the main force.

[0016] From time t to time t+i, the position and posture of the slave robot arm satisfies the following formula:

[0017] P s (t+i)=P s (t)+k·ΔP m (i)

[0018]

[0019] Where k is the proportional factor, P s (t+i) and P s (t) are the positions of the slave robot arm at time t and time t+i, respectively, Q s (t+i) and Q s(t) are the postures of the slave robot arm at time t and time t+i, ΔP m (i) is the position change of the teleoperator’s hand from time t to time t+i, ΔQ m (i) is the change in the posture of the teleoperator from time t to time t+i, is quaternion multiplication.

[0020] The calculation formula of the guiding force of the slave end robot arm is as follows:

[0021]

[0022] Among them, F att (q) is the gradient of the gravitational field, ρ is the gradient between the moving point q and the target point q in the potential field g The vector between m is the distance between the moving point and the target point in the initial state, and η is the gain coefficient.

[0023] 2. A human-machine collaborative remote control device based on active force guidance

[0024] The device includes a robot control cabinet, a switch, a remote control master hand, a resettable foot pedal and a slave robot arm; the slave robot arm is connected to the robot control cabinet, the robot control cabinet is connected to the switch, the switch is connected to the terminal, the remote control master hand is connected to the terminal, and the remote control master hand is connected to the resettable foot pedal.

[0025] The remote control master hand is connected to the resettable pedal via an external expansion board.

[0026] The external expansion board reserves interfaces 0-5, interface 0 is a VCC interface, and interfaces 1-5 are signal interfaces for connecting different devices.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] 1. The present invention proposes a novel incremental posture teleoperation mapping strategy based on foot pedals, which uses a resettable foot pedal to adjust the enable state and determine the establishment and interruption of posture mapping, thereby solving the problem of mismatch between the workspaces of master and slave teleoperation devices and realizing refined large-scale teleoperation control.

[0029] 2. The present invention improves the artificial potential field model, maps the guiding force of the artificial potential field to the main-end device of the remote operation system, and uses the potential field force as the active guiding force to provide a smooth force to the operator to guide the robot to move toward the target position, thereby solving the problem of low remote operation efficiency and realizing efficient remote operation control under human-machine collaboration. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1It is a schematic diagram of the control device of the present invention.

[0031] Figure 2 It is the wiring diagram of the control device of the present invention.

[0032] Figure 3 This is a wiring diagram of the remote control master expansion board of the present invention.

[0033] Figure 4 It is a flow chart of the control method of the present invention.

[0034] Figure 5 This is a schematic diagram of the master-slave mapping of the present invention.

[0035] Figure 6 This is a schematic diagram of guiding force calculation of the present invention.

[0036] Figure 7 This is a schematic diagram of remote operation under active force guidance of the present invention.

[0037] In the figure: a robotic arm control cabinet 1, a switch 2, a remote-operated master hand 3, a resettable foot pedal 4, a robotic arm 5, a laptop computer 6, a first connecting line 701, a second connecting line 702, a third connecting line 703, a fourth connecting line 704, a fifth connecting line 705, a remote-operated master hand expansion board output interface 801, and a remote-operated master hand expansion board input interface 802. DETAILED DESCRIPTION

[0038] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0039] The present invention proposes a human-machine cooperative remote control device based on active force guidance, such as Figure 1 and Figure 2 As shown, the device includes a robot control cabinet 1, a switch 2, a remote-operated master hand 3, a resettable foot pedal 4 and a slave robot 5; the slave robot 5 includes six rotating joints and has six degrees of freedom. A mechanical gripper is installed at the end for grasping operations. The slave robot 5 is connected to the robot control cabinet 1 through a fifth connecting line 705, the robot control cabinet 1 is connected to the switch 2 through a first connecting line 701, the switch 2 is connected to a terminal (such as a laptop computer 6) through a second connecting line 702, the remote-operated master hand 3 is connected to the terminal (such as a laptop computer 6) through a third connecting line 703, and the remote-operated master hand 3 is connected to the resettable foot pedal 4 through a fourth connecting line 704, ensuring that the wiring between each device is correct, safe, stable and in compliance with the specifications.

[0040] The remote control master hand 3 is connected to the resettable pedal 4 through an external expansion board. The resettable pedal 4 is used as a switch for the event trigger state of the present invention. The wiring between the remote control master hand 3 is as follows: Figure 3 shown. Figure 3In the embodiment, the wiring leading out of the remote-operation master hand expansion board output interface 801 is connected to the remote-operation master hand 3, which is used to output an enable signal to the remote-operation master hand, and the remote-operation master hand expansion board input interface 802 is used to receive input signals. The external expansion board reserves interfaces 0-5, interface 0 is a VCC interface, and interfaces 1-5 are signal interfaces, which can be connected to different devices to meet the needs of different control strategies. In this embodiment, the resettable pedal 4 is connected through interface 1 to obtain the state of the resettable pedal 4, output an enable signal, and control the event trigger state.

[0041] The present invention proposes a human-machine collaborative teleoperation control method based on active force guidance, such as Figure 4 As shown, by real-time detection of event triggering status, accurate mapping of the master device workspace to each sub-workspace of the slave device is achieved, and the guiding force is updated in real time through the guiding potential field to guide the operator's master end. The method includes the following steps:

[0042] Step 1: Construct the guiding force potential field of the slave end according to the ideal trajectory of the slave end manipulator;

[0043] The traditional artificial potential field applies the resultant force to the controlled object itself, directly controlling the movement of the controlled object. Based on the traditional artificial potential field model, only the gravitational potential field is considered. In the teleoperation system, the potential field gravity is mapped to the master-end operating device to guide the operator to control the movement of the slave-end manipulator. However, under the traditional artificial potential field model, the guiding force perceived by the operator is linear. When operating through the teleoperation system, the linear model will cause oscillation at the end of the guiding trajectory, reducing the operator's comfort and the accuracy of the guidance. The present invention establishes an artificial potential field based on the mission target trajectory at the slave end, maps the artificial potential field force to the master-end operating device to guide the operator's movement, and according to the operating force characteristics during the teleoperation process, the present invention designs a sinusoidal control method to apply to the artificial potential field to obtain a guiding force potential field, so as to make the gravitational potential field smooth and improve the operator's operating comfort and safety. Specifically, at the beginning of the guidance trajectory, when the guidance force is large, the change rate of the guidance force is weakened to ensure that the operator can better adapt to the change of the guidance force at the beginning; at the end of the guidance trajectory, when the guidance force is small, the change rate of the guidance force is also weakened to ensure that the operator has a more comfortable operating space before the end of the guidance, which can effectively avoid the generation of shock. The guidance force potential field of the slave end satisfies the following formula:

[0044]

[0045] ρ=ρ(q,q g )

[0046] Among them, U att (q) represents the guiding force potential field, ρ is the distance between the moving point q and the target point q in the potential field gThe vector between the two points has a magnitude of the Euclidean distance between the two points and a direction from the moving point to the target point. ρ() represents the vector calculation function between the two points. m is the distance between the moving point and the target point in the initial state, that is, the maximum distance, and η is the gain coefficient, which is used to adjust the range of the guiding force;

[0047] The corresponding gravity is the gradient of the gravitational field, representing the fastest changing direction of the gravitational potential field function:

[0048]

[0049] Among them, F att (q) is the gradient of the gravitational field, is the gradient.

[0050] By finding the gradient of the gravitational field, we can get the rate of change of the guiding force f:

[0051]

[0052] Therefore, at the beginning and end of the guidance trajectory, ρ = ρ m When and ρ = 0, the gravitational field gradient value is 0, that is, the change of the guiding force at the beginning and end of the guidance is small, and the guiding force change felt by the operator is more comfortable, providing the operator with a smooth active guiding force.

[0053] Step 2: Install a resettable foot pedal 4 at the master end and use the resettable foot pedal 4 as an event trigger switch to control the mapping of master and slave end devices and the establishment and cancellation of the main power guidance according to the event trigger state, so as to achieve coordinated, intuitive and efficient remote operation control by the operator.

[0054] Step 2 is as follows:

[0055] If the resettable foot pedal 4 is not triggered, the slave-end robotic arm is in a stationary state; if the resettable foot pedal 4 is triggered, the position and posture of the remote-operated master hand 3 of the master end and the slave-end robotic arm are obtained, and the position and posture of the remote-operated master hand 3 of the master end is mapped to the slave-end robotic arm and the position and posture of the slave-end robotic arm is updated to realize remote-operation control under human-machine collaboration; and the guiding force of the slave-end robotic arm is calculated according to the position of the slave-end robotic arm and the guiding force is mapped to the remote-operated master hand 3 of the master end, to complete the human-machine collaborative remote-operation control under the guidance of the main force.

[0056] The positions of the master and slave devices in the teleoperation system should be consistent. The teleoperation master hand and the slave manipulator in this system are heterogeneous, and it is impossible to establish a one-to-one correspondence between the joints. Therefore, a Cartesian space mapping method is adopted. The details are as follows:

[0057] First, obtain the position and posture coordinates of the teleoperator master hand relative to the world coordinate system, denoted as P m With Qm ; and respectively obtain the position and posture coordinates of the slave end robot arm relative to the base coordinate system, respectively denoted as P s With Q s ;

[0058] Next, obtain the enabling state of the resettable pedal at time t, denoted as E(t):

[0059]

[0060] Then, the changes in the position and posture of the teleoperator's main hand from time t to time t+i are calculated, and they satisfy the following formulas respectively:

[0061] ΔP m (i) = P m (t+i)-P m (t)

[0062]

[0063] Among them, P m (t+i) and P m (t) are the positions of the teleoperator’s master hand at time t and time t+i, respectively, Q m (t+i)Q m (t) are the postures of the teleoperator at time t and time t+i respectively.

[0064] The mapping relationship between the master and slave devices is determined according to the enabling state E of the resettable pedal. If E(t) = 0, even if the enabling state is not triggered and the master-slave mapping relationship is not established, the posture state of the slave robot arm from time t to time t+i is:

[0065] P s (t+i)=P s (t)

[0066] Q s (t+i)=Q s (t)

[0067] That is, the position and posture of the slave manipulator remain unchanged; if E(t) = 1, the state is triggered, and the master-slave mapping relationship is established, then from time t to time t+i, the position and posture of the slave manipulator satisfies the following formula:

[0068] P s (t+i)=P s (t)+k·ΔP m (i)

[0069]

[0070] That is, the posture change of the slave end manipulator and the master end teleoperation device is consistent, where k is the proportional factor, which can adjust the posture mapping ratio. The larger k is, the faster the movement speed of the slave end manipulator is when the movement speed of the master end teleoperation device is consistent. The size of the proportional factor k can be adjusted according to actual needs. By default, k = 1, P s (t+i) and P s (t) are the positions of the slave robot arm at time t and time t+i, respectively, Q s (t+i) and Q s (t) are the postures of the slave robot arm at time t and time t+i, ΔP m (i) is the position change of the teleoperator’s hand from time t to time t+i, ΔQ m (i) is the change in the posture of the teleoperator from time t to time t+i, is quaternion multiplication.

[0071] The application state of the active guiding force is controlled based on the event trigger state of the resettable pedal. When the pedal is pressed, the event is triggered, and a real-time and continuous active guiding force is applied to the teleoperation master device; when the pedal is released, the event is not triggered, and no guiding force is applied to the teleoperation master device. The calculation formula of the guiding force of the slave end manipulator is as follows:

[0072]

[0073] Among them, F att (q) is the gradient of the gravitational field, ρ is the gradient between the moving point q and the target point q in the potential field g The vector between them has the Euclidean distance between the two points and the direction from the moving point to the target point. m is the distance between the moving point and the target point in the initial state, that is, the maximum distance, and η is the gain coefficient, which is used to adjust the range of the guiding force.

[0074] Figure 5 The figure shows an example of the master-slave mapping relationship in the teleoperation system of the present invention. The working space of the master device is W m , the main equipment in the workspace is controlled by the operator by P m0 Move to P m1 ; The workspace of the slave robot is divided into a series of sub-workspaces W s0 , W s1 , W s2 ...Under the control of the master device, the slave robot arm is controlled by P s0 Move to P s1 , by P s1 Move to P s2 .

[0075] Figure 6The figure shows a schematic diagram of guiding force calculation in the teleoperation system of the present invention. The manipulator moves from the starting point S under the control of the master device. 0 Move to the target point S n , the ideal shortest motion path is l n Since the guiding force does not impose a mandatory constraint on the operation path, during the actual operation, the robot arm moves along the path l s Move to S i At this time, the distance between the robot arm and the target position can be divided into axial distance and normal distance along the ideal path. The guiding forces calculated according to the guiding potential field are F t and F n , calculate the resultant force of the guiding force and apply it to the main end operating device to guide the robot arm to S i+1 Position moved.

[0076] Figure 7 The figure shows the teleoperation under the guidance of the main force of the present invention. Figure 7 As shown, the specific implementation steps of the present invention are as follows:

[0077] Step 1: Read the position information P according to the control function of the teleoperation master hand 3 m and Q m , and read the enable state signal E of the resettable pedal 4 in real time, and read the posture information P according to the control function of the slave end robot 5 s and Q s , assuming that the teleoperation master hand 3 is at M 0 point, the slave end robot arm 5 is located at S 0 point, the robot arm target point is S n Points, such as Figure 7 As shown, for intuitiveness, the figure only contains location information;

[0078] Step 2: The operator steps on the resettable pedal 4, the enable signal is triggered from 0 to 1, the system detects the event trigger, the master-slave device mapping relationship and the active force guidance model are established, and the Figure 6 As shown, Sn is taken as the guiding target point, the potential field of the active guiding force is calculated, and the potential field force F is mapped to the master teleoperation device 3 in real time, guiding the operator to control the teleoperation master hand 3 by M 0 Move to M 1 ; At the same time, under the posture mapping of the master and slave devices, the slave robot arm 5 is 0 Move to S 1 ;

[0079] Step 3: In the working space of the teleoperation master hand 3, the operator controls the teleoperation master hand 3 to move to the boundary of the working space. When it is inconvenient to continue the operation, the operator releases the resettable pedal 4, and the enable signal changes from 1 to 0. The system detects that the event trigger state ends, the master-slave device mapping relationship and the main force guidance are cancelled, and the operator controls the teleoperation master hand 3 from M to 1 Back to the original M 0 Since the mapping relationship is not established, the slave robot arm 5 remains at S 1 point;

[0080] Step 4: The operator controls the teleoperation master hand 3 to return to M 0 After the point is clicked, the reset pedal 4 is stepped on again, and the enable signal is triggered from 0 to 1 again. The system detects the event trigger, and the master-slave mapping relationship and the active force guidance model are established. At this time, the slave end robot arm 5 is from S 1 The real-time guiding force is calculated and mapped to the master teleoperation device 3, guiding the operator to move the teleoperated manipulator to the point Sn. Under the guidance of the main force, the operator controls the teleoperated master hand device 3 from M 0 Move to M 1 ; Under the posture mapping of the master and slave devices, the slave robot arm 5 is composed of S 1 Move to S 2 .

[0081] Step 5: Repeat the above steps, and establish and cancel the teleoperation mapping relationship and the main force guidance model through the event trigger mechanism. The slave task space is divided into a series of subspaces, and the operation guidance force under each subspace is calculated. The operator controls the teleoperation master device 3. Under the guidance of the main force, the teleoperation slave manipulator 5 is controlled by S 0 Move to S n , the whole process is efficient and stable.

[0082] In the above operation process, the target point of the teleoperation task can be determined according to the actual task requirements, and the guiding force potential field can be established under the working space of the slave end manipulator. Combined with the event triggering strategy, the teleoperation task space is divided, and the active guiding force is calculated in real time under each task subspace to guide the operator to control the teleoperation device to move in the direction of the target point. The guiding force shows a trend of smooth change, and the operation process is intuitive and reliable. The control strategy of the present invention completes the precise mapping of the working space of the master and slave end devices through the coordinated control of the operator's hands and feet, and introduces the guiding force potential field model to guide the operator to operate intuitively and stably, improve the efficiency of teleoperation operation execution, and realize efficient teleoperation control under human-machine collaboration.

[0083] Finally, it should be noted that the above embodiments and explanations are only used to illustrate the technical solution of the present invention rather than to limit it. Those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the spirit and scope disclosed in the technical solution of the present invention, which should be included in the scope of protection of the claims of the present invention.

Claims

1. A human-machine collaborative teleoperation control method based on active force guidance, characterized in that: The following steps are involved: Step 1: Construct the guiding force potential field of the slave end according to the ideal trajectory of the slave end manipulator; Step 2: Install a resettable foot pedal (4) at the master end and use the resettable foot pedal (4) as an event trigger switch to control the mapping of the master and slave end devices and the establishment and cancellation of the main power guidance according to the event trigger state, so as to realize the remote operation control of the operator.

2. The human-machine collaborative teleoperation control method based on active force guidance according to claim 1 is characterized in that: In step 1, the guiding force potential field of the slave end satisfies the following formula: p=p(q,q g ) Among them, U att (q) represents the guiding force potential field, ρ is the distance between the moving point q and the target point q in the potential field g The vector between two points, ρ() represents the vector calculation function between two points, ρ m is the distance between the moving point and the target point in the initial state, and η is the gain coefficient.

3. The human-machine collaborative teleoperation control method based on active force guidance according to claim 1 is characterized in that: The step 2 is specifically as follows: If the resettable foot pedal (4) is not triggered, the slave end robot arm is in a stationary state; if the resettable foot pedal (4) is triggered, the positions of the teleoperation master hand (3) of the master end and the slave end robot arm are obtained, the position of the teleoperation master hand (3) of the master end is mapped to the slave end robot arm and the position of the slave end robot arm is updated, so as to realize teleoperation control under human-machine collaboration; And the guiding force of the slave end robot arm is calculated according to the position of the slave end robot arm and the guiding force is mapped to the teleoperation master hand (3) of the master end, so as to complete the human-machine collaborative teleoperation control under the guidance of the main force.

4. The human-machine collaborative teleoperation control method based on active force guidance according to claim 3 is characterized in that: From time t to time t+i, the position and posture of the slave robot arm satisfies the following formula: P s (t+i)=P s (t)+k·ΔP m (i) Where k is the proportional factor, P s (t+i) and P s (t) are the positions of the slave robot arm at time t and time t+i, respectively, Q s (t+i) and Q s (t) are the postures of the slave robot arm at time t and time t+i, ΔP m (i) is the position change of the teleoperator’s hand from time t to time t+i, ΔQ m (i) is the change in the posture of the teleoperator from time t to time t+i, is quaternion multiplication.

5. The human-machine collaborative teleoperation control method based on active force guidance according to claim 3 is characterized in that: The calculation formula of the guiding force of the slave end robot arm is as follows: Among them, F att (q) is the gradient of the gravitational field, ρ is the gradient between the moving point q and the target point q in the potential field g The vector between m is the distance between the moving point and the target point in the initial state, and η is the gain coefficient.

6. A human-machine collaborative remote control device based on active force guidance, characterized in that: The invention comprises a mechanical arm control cabinet (1), a switch (2), a remote control master hand (3), a resettable foot pedal (4) and a slave end mechanical arm (5); the slave end mechanical arm (5) is connected to the mechanical arm control cabinet (1), the mechanical arm control cabinet (1) is connected to the switch (2), the switch (2) is connected to a terminal, the remote control master hand (3) is connected to the terminal, and the remote control master hand (3) is connected to the resettable foot pedal (4).

7. The human-machine collaborative teleoperation control device based on active power guidance according to claim 6, characterized in that: The remote control main hand (3) is connected to the resettable pedal (4) via an external expansion board.

8. The human-machine collaborative teleoperation control device based on active power guidance according to claim 7, characterized in that: The external expansion board reserves interfaces 0-5, interface 0 is a VCC interface, and interfaces 1-5 are signal interfaces for connecting different devices.

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