Force/Position Hybrid Control Of Manipulator Based On Adaptive Sliding Mode Algorithm

The force/position hybrid control problem of the manipulator has been a hot issue widely concerned by scholars at home and abroad.The focus of its research is how to control the manipulator to ensure the high accuracy of its control and the fast response speed of the system.In industrial production,mechanical arms are often used for various operations.When complex assembly,precision grinding and other operations are involved,it is necessary not only to control their motion trajectory,but also to control the binding force generated by environmental constraints,as well as the clamping internal force generated when multiple mechanical arm end actuators simultaneously control the same object,this is the content that needs to be studied in this paper.In this paper,the corresponding dynamic models were established for the force/position hybrid control problem of a constrained single manipulator,the force/position hybrid control problem of a constrained multi-manipulator system,and the force/position hybrid control problem of a multi-manipulator system affected by uncertainties such as friction.Based on the self-adaptive sliding mode algorithm,the force/position hybrid control of the manipulator was realized by combining the order reduction method,fuzzy algorithm and robust algorithm.The main contents of this paper are as follows:The force/position hybrid control problem of a constrained single manipulator was studied.Firstly,based on the dynamic equation of the constrained single manipulator,the constrained reduced order dynamic model of the single manipulator was obtained by reducing its order through the constraint equation.Then the position control and constraint control were integrated in the same controller,and the adaptive sliding mode algorithm was combined with the order reduction method to design an adaptive reduced order sliding mode force/position hybrid controller based on the dynamic equation of the constrained single manipulator.Finally,the stability of the system was proved based on Lyapunov method.The simulation results indicate that the designed control scheme not only has a fast system response speed for the constrained single manipulator,but also has an excellent tracking effect for the expected trajectory,and can stabilize the force error in a very small range.In order to solve the problem of force/position hybrid control of constrained multi-manipulator system caused by environmental constraints at the end of the system,a hybrid force/position control method of constrained multi-manipulator system based on adaptive reduced order sliding mode algorithm was proposed.Firstly,the dynamic model of the multi-manipulator system was established by using multiple coordinate systems,and the dynamic model of the multi-manipulator system was established based on the dynamic model of the controlled object,thus the dynamic model of the constrained multi-manipulator system was established based on the constraint equation.Secondly,the position control,constraint control and internal force control were introduced into the same controller,and the adaptive sliding mode algorithm was combined with the order reduction method to design an adaptive reduced order sliding mode force/position hybrid controller based on the constrained multi-manipulator system.Finally,based on Lyapunov method,the stability of the system was proved.The simulation results show that the method not only ensures the high accuracy of the controller and the fast response speed of the system,but also ensures that the constraint error and internal force error are stable in a very small range.The simulation results indicate that the control scheme is effective.Aiming at the problem of force/position hybrid control of multi-manipulator system affected by uncertain factors such as friction,a fuzzy adaptive robust sliding mode control method for multi-manipulator system was proposed.Firstly,the multi-manipulator system model was built by the multi-manipulator dynamics equation and object dynamics equation affected by uncertain factors such as friction.Secondly,the fuzzy algorithm was combined with the adaptive sliding mode algorithm to compensate the uncertain factors and unknown nonlinear items,and the reliability of the system was improved through the robust algorithm.A fuzzy adaptive robust sliding mode force/position hybrid controller based on the multi-manipulator system affected by the uncertain factors such as friction was designed.Finally,based on Lyapunov method,the stability of the system was proved.The feasibility and superiority of the control scheme are verified by simulation.