A tracking control method for a multi-degree-of-freedom human-machine collaborative coupling system

Abstract

The application discloses a tracking control method for a multi-degree-of-freedom man-machine cooperation coupling system, relates to the field of multi-degree-of-freedom man-machine cooperation coupling system control, and comprises the following steps: a dynamic model of the multi-degree-of-freedom man-machine cooperation coupling system including actuator faults is established; a state space model is established based on the dynamic model; based on the state space model and a preset expected trajectory of the multi-degree-of-freedom man-machine cooperation coupling system, a tracking error of the multi-degree-of-freedom man-machine cooperation coupling system is obtained; a specified time preset performance function is designed, and a fault-tolerant controller of the multi-degree-of-freedom man-machine cooperation coupling system is established; and based on the tracking error, the multi-degree-of-freedom man-machine cooperation coupling system is controlled through the fault-tolerant controller, so that the tracking error of the multi-degree-of-freedom man-machine cooperation coupling system converges within the specified time, and the controllability and accuracy of the multi-degree-of-freedom man-machine cooperation coupling system are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of multi-degree-of-freedom human-robot collaborative coupling system control, and in particular to a tracking control method for a multi-degree-of-freedom human-robot collaborative coupling system. BACKGROUND

[0002] With the rapid development of intelligent manufacturing, robot technology and human-robot collaborative control technology, multi-degree-of-freedom human-robot collaborative coupling systems are increasingly widely used in complex operation scenarios such as industrial production. Human-robot collaborative systems complete high-precision operation tasks through the cooperation of robots and operators, which can effectively improve work efficiency. However, multi-degree-of-freedom human-robot collaborative coupling systems usually have highly nonlinear, strongly coupled and time-varying characteristics, and require high-precision control strategies to ensure the tracking accuracy and stability of the system. In addition, during long-term operation, actuators may fail, which not only leads to a decrease in trajectory tracking accuracy, but also affects task execution effectiveness and operation safety. Therefore, multi-degree-of-freedom human-robot collaborative coupling systems need to have fault tolerance to ensure the reliability and safety of the system in complex tasks and variable environments. Therefore, through systematic research on the control theory of human-robot collaborative coupling systems, innovative control schemes are proposed to improve the safety and stability of the system, which is of great significance for solving the problems of existing technologies and promoting the widespread application of human-robot collaborative coupling systems. SUMMARY

[0003] The purpose of the present application is to provide a tracking control method for a multi-degree-of-freedom human-robot collaborative coupling system, which can improve the controllability and accuracy of the multi-degree-of-freedom human-robot collaborative coupling system, effectively prevent the influence of actuator failure on the stability and safety of the multi-degree-of-freedom human-robot collaborative coupling system, and enhance the reliability of the multi-degree-of-freedom human-robot collaborative coupling system in complex human-robot interaction environments. At the same time, when applied to hardware devices, the running speed of the hardware devices can be improved.

[0004] To achieve the above-mentioned purpose, the present application provides the following solutions:

[0005] In a first aspect, the present application provides a tracking control method for a multi-degree-of-freedom human-robot collaborative coupling system, comprising:

[0006] establishing a dynamics model of a multi-degree-of-freedom human-robot collaborative coupling system including actuator failure.

[0007] Based on the dynamics model, a state space model of the multi-degree-of-freedom human-robot collaborative coupling system is established.

[0008] Based on the state space model and the preset desired trajectory of the multi-degree-of-freedom human-robot collaborative coupling system, the tracking error of the multi-degree-of-freedom human-robot collaborative coupling system is obtained.

[0009] design a specified time preset performance function, and establish a fault-tolerant controller of the multi-degree-of-freedom man-machine cooperation coupled system; wherein the specified time preset performance function is used to obtain a dynamic convergence boundary of the tracking error within a specified time.

[0010] Based on the tracking error, the multi-degree-of-freedom man-machine cooperation coupled system is controlled by the fault-tolerant controller, so that the tracking error of the multi-degree-of-freedom man-machine cooperation coupled system converges within a specified time.

[0011] According to the specific embodiments provided by the present application, the present application has the following technical effects:

[0012] The present application provides a tracking control method for a multi-degree-of-freedom man-machine cooperation coupled system, which can effectively make the tracking error converge within a specified time to the dynamic convergence boundary by introducing a specified time preset performance function, thereby improving the controllability and accuracy of the multi-degree-of-freedom man-machine cooperation coupled system. At the same time, the multi-degree-of-freedom man-machine cooperation coupled system is controlled in a closed loop by using the tracking error as a feedback signal and combining a fault-tolerant controller, which not only effectively prevents the influence of the failure of the actuator on the stability and safety of the multi-degree-of-freedom man-machine cooperation coupled system, but also enhances the reliability of the multi-degree-of-freedom man-machine cooperation coupled system in a complex man-machine interaction environment. BRIEF DESCRIPTION OF DRAWINGS

[0013] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed in the embodiments will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor on the basis of these drawings.

[0014] Figure 1 A flowchart of a tracking control method for a multi-degree-of-freedom man-machine cooperation coupled system provided by an embodiment of the present application is shown in the figure.

[0015] Figure 2 A functional module diagram of a tracking control device for a multi-degree-of-freedom man-machine cooperation coupled system provided by an embodiment of the present application is shown in the figure.

[0016] Figure 3 A structural diagram of a computer device provided by an embodiment of the present application is shown in the figure. DETAILED DESCRIPTION

[0017] With reference to the drawings and embodiments of the present application, the technical solutions in the embodiments of the present application will be described clearly and completely. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of the present application.

[0018] In order to make the purpose, features and advantages of the present application more obvious and easy to understand, the present application will be further described in detail below with reference to the drawings and specific embodiments.

[0019] In one exemplary embodiment, as shown in Figure 1 A tracking control method for a multi-degree-of-freedom human-robot collaborative coupling system is provided, which is executed by a computer device, specifically, can be executed by a terminal or a server, or can be executed by a terminal and a server together. In the embodiments of the present application, the method comprises the following steps 101 to 105. Wherein:

[0020] Step 101, a dynamic model of a multi-degree-of-freedom human-robot collaborative coupling system including actuator faults is established.

[0021] Step 102, a state space model of the multi-degree-of-freedom human-robot collaborative coupling system is established based on the dynamic model.

[0022] Step 103, based on the state space model and the preset desired trajectory of the multi-degree-of-freedom human-robot collaborative coupling system, a tracking error of the multi-degree-of-freedom human-robot collaborative coupling system is obtained.

[0023] Step 104, a specified time preset performance function is designed, and a fault-tolerant controller of the multi-degree-of-freedom human-robot collaborative coupling system is established; wherein the specified time preset performance function is used to obtain the dynamic convergence boundary of the tracking error within a specified time.

[0024] Step 105, based on the tracking error, the multi-degree-of-freedom human-robot collaborative coupling system is controlled by the fault-tolerant controller, so that the tracking error of the multi-degree-of-freedom human-robot collaborative coupling system converges within a specified time.

[0025] The steps 101 to 105 described above improve the stability and safety of the multi-degree-of-freedom human-robot collaborative coupling system, and enhance the reliability of the multi-degree-of-freedom human-robot collaborative coupling system in a complex human-robot interaction environment.

[0026] In another exemplary embodiment of the present application, the expression of the dynamic model is:

[0027]

[0028]

[0029] in, For the angular position of the link side in a multi-degree-of-freedom human-machine collaborative coupling system, For the angular velocity on the link side of a multi-degree-of-freedom human-machine collaborative coupling system, For the angular acceleration on the link side of a multi-degree-of-freedom human-machine collaborative coupling system, It is a symmetric inertial matrix. The Coriolis force matrix, For the gravity matrix, for The unknown modeling part, for The unknown modeling part, for The unknown modeling part, Where is the elastic constant. The angular position on the motor side of the multi-degree-of-freedom human-machine collaborative coupling system. For the angular velocity on the motor side of a multi-degree-of-freedom human-machine collaborative coupling system, For the angular acceleration on the motor side of a multi-degree-of-freedom human-machine collaborative coupling system, Let be the moment of inertia of the motor. The natural damping coefficient, for The unknown modeling part, for The unknown modeling part, For the control torque to be designed, For the health status of the actuator, ; An additive fault in the actuator. ; For unknown external interference in multi-degree-of-freedom human-machine collaborative coupling systems, The number of joints in a multi-degree-of-freedom human-machine collaborative coupling system.

[0030] In another exemplary embodiment of this application, the expression of the state-space model is:

[0031]

[0032]

[0033]

[0034]

[0035] wherein, is the 1st state, is the 2nd state, is the 3rd state, is the 4th state, is the 1st state's 1st derivative, is the 2nd state's 1st derivative, is the 3rd state's 1st derivative, is the 4th state's 1st derivative, is the 1st state's symmetric inertia matrix, is the total disturbance on the link side of the multi-DOF human-robot coupled system, is the total disturbance on the link side of the multi-DOF human-robot coupled system.

[0036] In another exemplary embodiment of the present application, the expression of the tracking error is:

[0037]

[0038] wherein, is the angular position error on the link side of the multi-DOF human-robot coupled system, is the angular velocity error on the link side of the multi-DOF human-robot coupled system, is the angular position error on the motor side of the multi-DOF human-robot coupled system, is the angular velocity error on the motor side of the multi-DOF human-robot coupled system, is the 1st virtual controller of the multi-DOF human-robot coupled system, is the 2nd virtual controller of the multi-DOF human-robot coupled system, is the 3rd virtual controller of the multi-DOF human-robot coupled system, is the desired angular position, is the desired angular velocity, , is the desired angular velocity of the 1st joint of the multi-DOF human-robot coupled system, is the desired angular velocity of the 2nd joint of the multi-DOF human-robot coupled system, is the desired angular velocity of the n-th joint of the multi-DOF human-robot coupled system.

[0039] In another example embodiment of the present application, during the use of the multi-degree-of-freedom human-robot collaborative coupling system, if the tracking error of the multi-degree-of-freedom human-robot collaborative coupling system cannot converge within a limited time, it may cause inaccurate trajectory tracking, affecting the completion effect of the operation task and the safety of the user. To solve this problem, the present application designs a specified time preset performance function to control the tracking error to converge to the dynamic convergence boundary within the specified time, thereby improving the tracking accuracy and stability of the multi-degree-of-freedom human-robot collaborative coupling system and ensuring the reliability of the multi-degree-of-freedom human-robot collaborative coupling system control. The expression of the specified time preset performance function is:

[0040]

[0041] wherein, is the dynamic convergence boundary within the specified time, is the initial value of the specified time preset performance function, is the final value of the specified time preset performance function, is the adjustment factor of the specified time preset performance function, is the convergence time of the multi-degree-of-freedom human-robot collaborative coupling system, is the time, and satisfies ; is the adjustment factor of the specified time preset performance function.

[0042] In another example embodiment of the present application, the expression of the fault-tolerant controller is:

[0043]

[0044] wherein, is the joint index of the multi-degree-of-freedom human-robot collaborative coupling system, and n is the number of joints of the multi-degree-of-freedom human-robot collaborative coupling system, is the sliding mode surface function, is the first derivative of the sliding mode surface function, is the sliding mode surface function of the i th joint, is the first derivative of the sliding mode surface function of the i th joint, is the estimated value of the health state of the actuator, is the estimated value of the health state of the actuator of the i th joint, is the first derivative of the estimated value of the health state of the actuator of the i th joint, is the first derivative of , is the first derivative of , is the first derivative of , is the first derivative of is the first constant to be designed, is the second constant to be designed, is a symbol function, is the fourth virtual controller of the multi-degree-of-freedom human-robot collaborative coupling system, is the fourth virtual controller of the i th joint of the multi-degree-of-freedom human-robot collaborative coupling system, is the adaptive gain of the i th joint, is the motor side angular velocity error of the i th joint of the multi-degree-of-freedom human-robot collaborative coupling system, is the third constant to be designed, is the fourth constant to be designed, is the fifth constant to be designed, is the sixth constant to be designed, is the seventh constant to be designed, is the eighth constant to be designed. , ; , , , , are all normal numbers, and satisfy , , , , .

[0045] In one embodiment, the stability of the multi-degree-of-freedom human-robot collaborative coupling system and the effectiveness of the controller are verified by constructing a Lyapunov function.

[0046] The constructed Lyapunov function is in the following form:

[0047]

[0048]

[0049]

[0050] wherein, is the conversion error, represents the conversion error of the i th joint, represents the error conversion function of the i th joint, is the symmetric inertia matrix of the 2 nd state, and are both constants to be designed, , is the total Lyapunov function, is the first Lyapunov function, This is the second Lyapunov function. This is the third Lyapunov function. This is the fourth Lyapunov function. This is the fifth Lyapunov function.

[0051] right Differentiation yields:

[0052]

[0053] in, for The first derivative, for The first derivative, Let $\frac{i}{i}$ be the link side angle position error of the $i$-th joint in a multi-degree-of-freedom human-machine collaborative coupling system. Let be the first derivative of the link side angle position error of the i-th joint in a multi-degree-of-freedom human-machine collaborative coupling system. Let i be the dynamic convergence boundary of the i-th joint within a specified time. for The first derivative, As an intermediate variable, , It is a constant to be designed.

[0054] right Differentiation yields:

[0055]

[0056] in, for The first derivative, for The first derivative, for The first derivative, , yes The upper realm, It is a constant to be designed.

[0057] right Differentiation yields:

[0058]

[0059] in, It is a constant to be designed.

[0060] right Differentiation yields:

[0061]

[0062] wherein, is a constant to be designed.

[0063] Taking the derivative of we get

[0064]

[0065] Combining equations (13) - (17) and substituting into we get

[0066]

[0067] Since

[0068]

[0069]

[0070]

[0071]

[0072]

[0073] Substituting equations (19) - (23) into equation (18) we get

[0074]

[0075] wherein, , , .

[0076]

[0077]

[0078] As can be seen from equation (25) To solve the error boundary problem in the system, multiplying equation (24) by we get

[0079]

[0080] Further simplification of equation (27) yields:

[0081]

[0082] From equation (28), we can see that:

[0083]

[0084]

[0085]

[0086] As can be seen from equations (29) to (31), all signals involved in the multi-degree-of-freedom human-machine collaborative coupling system are bounded.

[0087] Finally, the convergence of the angular position tracking error over a specified time is discussed, and the simplified formula ( We can obtain:

[0088]

[0089] Similarly, it can be deduced that... Therefore, the angular position tracking error satisfies ,when hour, It can converge to the boundary. .

[0090] In summary, this application introduces a time-preset performance function, enabling the tracking error of a multi-DOF human-machine collaborative coupling system to converge to the dynamic convergence boundary within a specified time during the control process. By using the time-preset performance function, the convergence speed and tracking accuracy of the multi-DOF human-machine collaborative coupling system can be effectively guaranteed, improving the safety and reliability of the human-machine interaction process and providing users with more stable and efficient interaction technology support.

[0091] This application designs a fault-tolerant controller that can promptly adjust the output signal when an actuator fails, thereby ensuring the tracking accuracy and stability of the multi-degree-of-freedom human-machine collaborative coupling system. The fault-tolerant controller not only effectively improves the reliability of the multi-degree-of-freedom human-machine collaborative coupling system during long-term use, but also ensures the safety and continuity of the human-machine interaction process.

[0092] Based on the same inventive concept, such as Figure 2As shown, the embodiment of the present application further provides a tracking control device for a multi-degree-of-freedom human-robot collaborative coupling system, the device comprising:

[0093] The dynamic model establishing module 201 is configured to establish a dynamic model of the multi-degree-of-freedom human-robot collaborative coupling system including actuator faults.

[0094] The state space model establishing module 202 is configured to establish a state space model of the multi-degree-of-freedom human-robot collaborative coupling system based on the dynamic model.

[0095] The tracking error obtaining module 203 is configured to obtain a tracking error of the multi-degree-of-freedom human-robot collaborative coupling system based on the state space model and a preset desired trajectory of the multi-degree-of-freedom human-robot collaborative coupling system.

[0096] The controller establishing module 204 is configured to design a specified time preset performance function and establish a fault-tolerant controller of the multi-degree-of-freedom human-robot collaborative coupling system, wherein the specified time preset performance function is used to obtain a dynamic convergence boundary of the tracking error within a specified time.

[0097] The tracking control module 205 is configured to control the multi-degree-of-freedom human-robot collaborative coupling system through the fault-tolerant controller based on the tracking error, so that the tracking error of the multi-degree-of-freedom human-robot collaborative coupling system converges within a specified time.

[0098] In an exemplary embodiment, a computer device can be provided, which can be a server or a terminal, and an internal structure diagram thereof can be as shown in the figure. Figure 3 The computer device comprises a processor, a memory, an input / output interface (I / O) and a communication interface. The processor, the memory and the input / output interface are connected through a system bus, and the communication interface is connected to the system bus through the input / output interface. The processor of the computer device is configured to provide computing and control capabilities. The memory of the computer device comprises a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program and a database. The internal memory provides an environment for the operating system and the computer program in the non-volatile storage medium to run. The database of the computer device is configured to store data of a multi-degree-of-freedom human-robot collaborative coupling system. The input / output interface of the computer device is configured to exchange information between the processor and external devices. The communication interface of the computer device is configured to communicate with external terminals through network connection. The computer program is executed by the processor to implement a tracking control method for a multi-degree-of-freedom human-robot collaborative coupling system.

[0099] Those skilled in the art can understand that, Figure 3The structure shown in the figure is only a block diagram of part of the structure related to the scheme of the present application, and does not constitute a limitation on the computer device to which the scheme of the present application is applied. The specific computer device can include more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components. In one exemplary embodiment, a computer device is provided, including a memory and a processor, the memory storing a computer program, and the processor implementing the tracking control method for the multi-degree-of-freedom human-machine cooperation coupling system described above when executing the computer program.

[0100] It should be noted that the user information (including but not limited to user equipment information, user personal information, etc.) and data (including but not limited to data for analysis, stored data, displayed data, etc.) involved in the present application are all information and data authorized by the user or authorized by all parties, and the collection, use and processing of the relevant data need to comply with relevant regulations.

[0101] The technical features of the above embodiments can be combined in any manner. To make the description concise, not all possible combinations of the technical features in the above embodiments are described, but as long as the combinations of the technical features do not exist contradictions, they should be considered as the scope of the present application.

[0102] The principles and implementation modes of the present application are described by using specific examples in the present application. The above description of the embodiments is only to help understand the method of the present application and its core idea; at the same time, for those skilled in the art, according to the idea of the present application, the specific implementation mode and application range will be changed. In conclusion, the content of the present application should not be understood as a limitation.

Claims

1. A tracking control method for a multi-degree-of-freedom human-robot collaborative coupling system, characterized by, The method comprises: A dynamic model of a multi-degree-of-freedom human-machine cooperative coupling system including actuator faults is established; the expression of the dynamic model is: ； ； wherein, is the angle position of the linkage side of the multi-degree-of-freedom human-robot collaborative coupled system, is the angular velocity of the linkage side of the multi-degree-of-freedom human-robot collaborative coupled system, is the angular acceleration of the linkage side of the multi-degree-of-freedom human-robot collaborative coupled system, is the symmetric inertia matrix, is the Coriolis force matrix, is the gravity matrix, is unknown modeling part of unknown modeling part of unknown modeling part of unknown modeling part of unknown modeling part of is the elastic constant, is the angle position of the motor side of the multi-degree-of-freedom human-robot collaborative coupled system, is the angular velocity of the motor side of the multi-degree-of-freedom human-robot collaborative coupled system, is the angular acceleration of the motor side of the multi-degree-of-freedom human-robot collaborative coupled system, is the moment of inertia of the motor, is the natural damping coefficient, is unknown modeling part of unknown modeling part of unknown modeling part of is the control torque to be designed, is the health state of the actuator, is the additive fault in the actuator, is the unknown external disturbance in the multi-degree-of-freedom human-robot collaborative coupled system; Based on the dynamic model, a state space model of the multi-degree-of-freedom human-machine cooperative coupling system is established; Based on the state space model and the preset expected trajectory of the multi-degree-of-freedom human-machine cooperative coupling system, a tracking error of the multi-degree-of-freedom human-machine cooperative coupling system is obtained; A specified time preset performance function is designed, and a fault-tolerant controller of the multi-degree-of-freedom human-machine cooperative coupling system is established; wherein the specified time preset performance function is used to obtain the dynamic convergence boundary of the tracking error within a specified time; Based on the tracking error, the multi-degree-of-freedom human-machine cooperative coupling system is controlled by the fault-tolerant controller, so that the tracking error of the multi-degree-of-freedom human-machine cooperative coupling system converges within a specified time.

2. The tracking control method for a multi-degree-of-freedom human-robot collaborative coupled system according to claim 1, characterized in that, The expression of the state space model is: ； ； ； ； wherein, is the first state, is the second state, is the third state, is the fourth state, is the first state first derivative, is the second state first derivative, is the third state first derivative, is the fourth state first derivative, is the first state symmetric inertia matrix, is the multi-degree-of-freedom human-robot coupled system link side total disturbance, is the multi-degree-of-freedom human-robot coupled system link side total disturbance.

3. The tracking control method for a multi-degree-of-freedom human-robot collaborative coupled system according to claim 2, characterized in that, The expression of the tracking error is: ； wherein, is a link-side angular position error of a multi-degree-of-freedom human-robot collaborative coupled system, is a link-side angular velocity error of a multi-degree-of-freedom human-robot collaborative coupled system, is a motor-side angular position error of a multi-degree-of-freedom human-robot collaborative coupled system, is a motor-side angular velocity error of a multi-degree-of-freedom human-robot collaborative coupled system, is a first virtual controller of a multi-degree-of-freedom human-robot collaborative coupled system, is a second virtual controller of a multi-degree-of-freedom human-robot collaborative coupled system, is a third virtual controller of a multi-degree-of-freedom human-robot collaborative coupled system, is a desired angular position, is a desired angular velocity. 4.The tracking control method for a multi-degree-of-freedom human-robot collaborative coupling system according to claim 2, characterized in that, The expression of the specified time preset performance function is: ； wherein, is a dynamic convergence boundary for a specified time, is an initial value of the performance function for a specified time, is a final value of the performance function for a specified time, is a tuning factor of the performance function for a specified time, is a convergence time of the multi-degree-of-freedom human-robot collaborative coupled system, is a time.

5. The tracking control method for a multi-degree-of-freedom human-robot collaborative coupled system according to claim 3, wherein, The expression of the fault-tolerant controller is: ； wherein, is the joint index of the multi-degree-of-freedom human-robot collaborative coupling system, is the number of joints of the multi-degree-of-freedom human-robot collaborative coupling system, is the sliding surface function, is the first derivative of the sliding surface function, is the sliding surface function of the ith joint, is the first derivative of the sliding surface function of the ith joint, is the estimated value of the health state of the actuator, is the estimated value of the health state of the actuator of the ith joint, is the first derivative of the estimated value of the health state of the actuator of the ith joint, is the first derivative of , is the first derivative of , is the first constant to be designed, is the second constant to be designed, is the sign function, is the fourth virtual controller of the multi-degree-of-freedom human-robot collaborative coupling system, is the fourth virtual controller of the ith joint of the multi-degree-of-freedom human-robot collaborative coupling system, is the adaptive gain of the ith joint, is the motor-side angular velocity error of the ith joint of the multi-degree-of-freedom human-robot collaborative coupling system, is the third constant to be designed, is the fourth constant to be designed, is the fifth constant to be designed, is the sixth constant to be designed, is the seventh constant to be designed, is the eighth constant to be designed, , ; , , , , are all normal numbers, and satisfy , , , , .

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