CN-121973245-A - Inequality constraint control method for friction stir welding robot with complex curved surface

CN121973245ACN 121973245 ACN121973245 ACN 121973245ACN-121973245-A

Abstract

The invention discloses an inequality constraint control method for a friction stir welding robot with a complex curved surface, which comprises the steps of collecting the angular displacement of a driving motor of the friction stir welding robot and the input torque of a load driven by the driving motor; and controlling the driving motor according to the angular displacement and the input torque by using a pre-established inequality constraint control model. According to the method, the driving motor is controlled according to the angular displacement and the input torque of the driving motor by utilizing a pre-established inequality constraint control model, so that when the angular displacement is far away from the boundary, the control emphasis is placed on track tracking, and the angular displacement is far away from the boundary and moves towards the expected track, and the method has the advantages of being high in stability and strong in robustness.

Inventors

WU QILIN
WAN LONG
WANG SHAOKANG
YE JINHUI
TONG ZHIXIANG
SHU XI
HUANG TIFANG

Assignees

合肥大学
安徽万宇机械设备科技有限公司

Dates

Publication Date: 20260505
Application Date: 20260403

Claims (10)

1. An inequality constraint control method for a friction stir welding robot with a complex curved surface, the method comprising: Acquiring the angular displacement of a driving motor of the friction stir welding robot and the input torque of a load driven by the driving motor; And controlling the driving motor according to the angular displacement and the input torque by using a pre-established inequality constraint control model, wherein the inequality constraint control model is determined by a mechanical system dynamics model of the driving motor containing parameter uncertainty, a second-order constraint form of a mechanical system servo constraint of the driving motor and constraint force of the mechanical system of the driving motor under the condition of uncertainty, the mechanical system dynamics model of the driving motor containing parameter uncertainty is constructed based on a dynamic model of the driving motor under the inequality constraint, the second-order constraint form of the mechanical system servo constraint of the driving motor is constructed under the condition of being sufficiently smooth according to the mechanical system dynamics model of the driving motor containing parameter uncertainty, and the dynamic model of the driving motor under the inequality constraint is obtained by converting the displacement of the driving motor from a bounded domain to a non-bounded domain while limiting the displacement of the driving motor within a preset stroke range based on the dynamic model of the driving motor.
2. The inequality constraint control method according to claim 1, wherein the process of constructing the inequality constraint control model includes: Based on a dynamic model of a driving motor, limiting the displacement of the driving motor within a preset travel range, and simultaneously converting the displacement of the driving motor from a bounded domain to an unbounded domain to obtain a dynamic model of the driving motor under the inequality constraint; constructing a dynamic model of a mechanical system where the driving motor is located with parameter uncertainty according to the dynamic model of the driving motor under inequality constraint, constructing a second-order constraint form of servo constraint of the mechanical system where the driving motor is located under a condition of being sufficiently smooth according to the dynamic model of the mechanical system where the driving motor is located with parameter uncertainty, and constructing constraint force of the mechanical system where the driving motor is located under the condition of uncertainty based on the second-order constraint form of the servo constraint of the mechanical system where the driving motor is located; Constructing a hypothesis requirement based on the mechanical system characteristics and the servo constraint characteristics of the driving motor; And decomposing an uncertainty part in the mechanical system dynamics model of the driving motor containing the parameter uncertainty based on the mechanical system dynamics model of the driving motor containing the parameter uncertainty, a second-order constraint form of the servo constraint of the mechanical system of the driving motor and the constraint force of the mechanical system of the driving motor under the condition of uncertainty, and establishing the inequality constraint control model according to the hypothesis requirement.
3. The inequality constraint control method according to claim 2, wherein the expression of the dynamic model of the driving motor under the inequality constraint is: Wherein, the The time is represented by the time period of the day, Representing angular displacement The corresponding unconstrained state variable is used to determine, Representation of Derivative of time, corresponding to angular velocity In the form of a variant of (a), Representation of Second derivative of time, corresponding to angular acceleration In the form of a variant of (a), Representing the functional form of an inertia matrix of the mechanical system where the driving motor is positioned after conversion, Representing the functional form of the coriolis force and centrifugal force terms, Representing the functional form of gravity, friction and conversion terms, An input torque indicative of the load is provided, Representing the inertia matrix of the mechanical system where the driving motor is positioned after conversion, Representing the inertia matrix of the drive motor, Representing the coriolis force and the centrifugal force, Representing the moment of non-linear damping, Representing the force of gravity, friction and conversion terms, Representing the moment of non-linear friction, Indicating the inertia of the drive motor, Indicating the upper limit of the angular displacement of the rotor of the drive motor, Representing the lower limit of the angular displacement of the rotor of the drive motor.
4. The inequality constraint control method according to claim 3, wherein the expression of the mechanical system dynamics model of the driving motor containing parameter uncertainty is: Wherein, the The time is represented by the time period of the day, Indicating the angular displacement of the rotor of the drive motor, Indicating the angular velocity of the rotor of the drive motor, Indicating the angular acceleration of the rotor of the drive motor, An uncertainty parameter representing the mechanical system in which the drive motor is located, An input torque indicative of the load is provided, Representing the inertia matrix of the mechanical system where the driving motor is positioned after conversion, Representing the coriolis force and the centrifugal force, Representing the non-linear friction force of the friction wheel, Representing gravitational force, frictional force, and conversion terms.
5. The inequality constraint control method according to claim 4, wherein the expression of the second-order constraint form of the servo constraint of the mechanical system in which the driving motor is located is: Wherein, the Indicating the index of the drive motor, Indicating the total number of degrees of freedom of the mechanical system in which the drive motor is located, Indicating the angular displacement of the rotor of the drive motor, The time is represented by the time period of the day, Representing acceleration constrained transformation matrices Is the first of (2) Line 1 The column elements are arranged in a row, Represent the first The angular acceleration of the rotor of the drive motor, Represent the first The generalized coordinate components corresponding to the servo constraints.
6. The inequality constraint control method according to claim 5, wherein the constraint force of the mechanical system in which the driving motor is located in the case of uncertainty is expressed as: Wherein, the Representing the ideal restraining force required by the mechanical system in which the drive motor is located, Representing angular displacement in dependence on generalized coordinates And time of A nominal inertia matrix of the mechanical system in which the drive motor is located after conversion, Representation of Is a square root matrix of (a), Representation of Is used for the inverse matrix of (a), Representing angular displacement in dependence on generalized coordinates And time of Is a matrix of the acceleration-constrained transformation, Representing angular displacement in dependence on generalized coordinates Angular velocity of And time of Is used to determine the state variable of (1), Representing angular displacement in dependence on generalized coordinates Angular velocity of And time of Is a combination of the coriolis force and the centrifugal force, Representing angular displacement in dependence on generalized coordinates And time of An inertial inverse matrix of a mechanical system in which the driving motor is positioned after conversion, Representing angular displacement in dependence on generalized coordinates And time of Nominal gravity, friction and transition term, Representing angular displacement in dependence on generalized coordinates And time of Is used for the nominal nonlinear friction force of the motor.
7. The inequality constraint control method according to claim 6, wherein the assumption requirement includes at least: (1) For any arbitrary A kind of electronic device , , wherein, An uncertainty parameter representing the mechanical system in which the drive motor is located, Representation of Taking any constant value of the mixture, and taking any constant value of the mixture, Representing angular displacement in dependence on generalized coordinates Uncertainty parameter And time of An inertia matrix converted by a mechanical system in which the driving motor is positioned; (2) exhibit consistency in terms of constraints, wherein, Representing angular displacement in dependence on generalized coordinates Angular velocity of And time of Is a matrix of the acceleration-constrained transformation, Representation of Is used for the matrix of derivatives of (c), Representing angular displacement in dependence on generalized coordinates Angular velocity of And time of Is set, the desired acceleration of (a); (3) For any given Acceleration constrained transformation matrix The full rank is set to be the full rank, Reversible; (4) Given the hypothesis in hypothesis (3), for a specified positive weighting matrix And (3) making: Wherein, the Representing angular displacement in dependence on generalized coordinates Uncertainty parameter And time of For optimal control of a weighted acceleration energy function is provided that, The representation defines a symbol of the presentation, Representing angular displacement in dependence on generalized coordinates And time of Is used to determine the positive weighting matrix of the (c), Representation of Is used to determine the transposed matrix of (a), Representing angular displacement in dependence on generalized coordinates And time of Is a matrix of the acceleration-constrained transformation, Representing angular displacement in dependence on generalized coordinates And time of A nominal inertia matrix of the mechanical system in which the drive motor is located after conversion, Representing angular displacement in dependence on generalized coordinates Uncertainty parameter And time of Is used for the feedback control of the gain matrix, Representing angular displacement in dependence on generalized coordinates And time of There is no inertial matrix of uncertainty in the drive motor, Representing a matrix of positive weights, present So that for all All have: Wherein, the The minimum number is indicated by the number of the minimum, The minimum characteristic value is indicated to be the value of the minimum characteristic, The number of servo constraints is represented by the number of servo constraints, Representation of Is to be used in the present invention, Representing angular displacement in dependence on generalized coordinates Uncertainty parameter And time of For optimal control of a weighted acceleration energy function is provided that, Uncertainty boundary parameters representing inertial systems Is determined, in the absence of uncertainty, 。
8. The inequality constraint control method according to claim 7, characterized in that the inequality constraint control model The method comprises the following steps: Wherein, the Wherein, the , Selection of Such that: Wherein, the Indicating the angular displacement of the rotor of the drive motor, Indicating the angular velocity of the rotor of the drive motor, The time is represented by the time period of the day, Representing the term of the ideal restraining force, Representing the initial condition compensation term(s), Representing the uncertainty suppression term(s), Representing the ideal restraining force required by the mechanical system in which the drive motor is located, Representing the control gain factor(s) of the system, Representing angular displacement in dependence on generalized coordinates And time of A nominal inertia matrix of the mechanical system in which the drive motor is located after conversion, Representation of Is used to determine the transposed matrix of (a), Representing angular displacement in dependence on generalized coordinates And time of Is a matrix of the acceleration-constrained transformation, Representing a matrix of positive weights Is the inverse of the (a) and (b), The error vector is represented as a function of the error vector, Representing angular displacement in dependence on generalized coordinates Angular velocity of And time of Is weighted by the lyapunov function, Representing angular displacement in dependence on generalized coordinates Angular velocity of And time of Is used for the damping term coefficient of the (a), Representing angular displacement in dependence on generalized coordinates Angular velocity of And time of An uncertainty boundary parameter of a mechanical system in which the driving motor is located, Representing angular displacement in dependence on generalized coordinates And time of Uncertainty boundary parameters of inertial system of (2) Is used for the estimation of the (c), A positive constant is indicated and a positive constant is indicated, Representing angular displacement in dependence on generalized coordinates Angular velocity of And time of Is used to determine the error vector of (a), A reference track item is represented and, Representing the acceleration-constrained transformation matrix, Inertial matrix representing the absence of uncertainty in the drive motor Is used for the uncertainty of the (c) in the (c), An inertia matrix representing the absence of uncertainty of the drive motor, Representing the coriolis force and the centrifugal force, Representing the force of gravity, friction and conversion terms, Representing coriolis force and centrifugal force Is used for the uncertainty of the (c) in the (c), Representing gravitational force, frictional force and conversion terms Is not determined by the uncertainty of (2).
9. A computer-readable storage medium, on which a computer program is stored, characterized in that the computer program, when executed by a processor, implements the inequality constraint control method for a friction stir welding robot for complex curved surfaces as set forth in any one of claims 1 to 8.
10. A controller comprising a memory, a processor, the memory having stored thereon a computer program, wherein the computer program, when executed by the processor, implements the inequality constraint control method for a friction stir welding robot for complex curved surfaces as set forth in any one of claims 1-8.

Description

Inequality constraint control method for friction stir welding robot with complex curved surface Technical Field The invention relates to the field of robot system dynamics control, in particular to an inequality constraint control method for a friction stir welding robot with a complex curved surface. Background In the rapid development of industrial automation and intelligent manufacturing technology, industrial robots are used as core execution units, and the efficiency and the product quality of a production line are directly affected. Particularly in the front-edge fields of semiconductor packaging, precise medical instrument manufacturing and the like, unprecedented high requirements are put on the control precision and dynamic response capability of a robot driving motor (the driving motor and a harmonic reducer can form a joint module of the robot). The complexity of the robot drive motor makes it inherently prone to uncertainty. As a multivariable, highly interconnected, time-varying nonlinear system, achieving accurate and efficient trajectory tracking by drive motors is a significant challenge. Disclosure of Invention The present invention aims to solve at least one of the technical problems in the related art to some extent. Therefore, an object of the present invention is to provide an inequality constraint control method for a friction stir welding robot with a complex curved surface, which can realize that when angular displacement is far away from a boundary, control emphasis is placed on track tracking, so that the angular displacement is far away from the boundary and moves towards a desired track, and has the advantages of high stability and strong robustness. A second object of the present invention is to propose a computer readable storage medium. A third object of the present invention is to propose a controller. In order to achieve the above purpose, the embodiment of the first aspect of the invention provides an inequality constraint control method for a friction stir welding robot with a complex curved surface, which comprises the steps of collecting angular displacement of a driving motor of the friction stir welding robot and input torque of a load driven by the driving motor, and controlling the driving motor according to the angular displacement and the input torque by using a pre-established inequality constraint control model, wherein the inequality constraint control model is determined by a driving motor dynamic model with parameter uncertainty, a second-order constraint form of a driving motor servo constraint of the driving motor and constraint force of the driving motor under the condition of uncertainty, the driving motor dynamic model with parameter uncertainty is constructed based on a dynamic model of the driving motor under the condition of inequality constraint, the driving motor dynamic model under the condition of inequality constraint is constructed according to the driving motor dynamic model with parameter uncertainty, and the driving motor dynamic model under the condition of inequality constraint is constructed by limiting the driving motor displacement within a preset range and simultaneously converting the driving range into a driving range from a range to a free range. According to the inequality constraint control method for the friction stir welding robot with the complex curved surface, provided by the embodiment of the invention, the driving motor is controlled according to the angular displacement and the input torque of the driving motor by utilizing the inequality constraint control model which is established in advance, so that when the angular displacement is far away from the boundary, the control emphasis is placed on track tracking, and the angular displacement is far away from the boundary and moves towards the expected track, and the method has the advantages of high stability and strong robustness. In addition, the inequality constraint control method for the friction stir welding robot with the complex curved surface provided by the embodiment of the invention can also have the following additional technical characteristics: According to one embodiment of the invention, the process of constructing the inequality constraint control model comprises the steps of limiting displacement of a driving motor in a preset travel range based on a dynamic model of the driving motor, converting the displacement of the driving motor from a bounded domain to an unbounded domain to obtain a dynamic model of the driving motor under the inequality constraint, constructing a mechanical system dynamics model of the driving motor with parameter uncertainty according to the dynamic model of the driving motor under the inequality constraint, constructing a second-order constraint form of a mechanical system servo constraint of the driving motor under the condition of being sufficiently smooth according to the mechanical system dynamics model of the driving motor w