A Combined Sliding Mode Motion Control Method for Flexible Manipulator

Abstract

The invention discloses a combined sliding mode motion control method of a flexible mechanical arm. The problem of motion control of flexible manipulators with disturbances and system uncertainties is studied at multiple time scales. Due to the multi-time scale characteristics of the flexible manipulator, it is easy to lead to ill-conditioned numerical problems by using the traditional method to design the controller. Based on the singular perturbation theory, the flexible manipulator is modeled as a singularly perturbed system with singular perturbation parameters and decomposed Fast and slow subsystems for describing rigid body motion and flexible vibration. On the slow time scale, considering the influence of external disturbance and parameter uncertainty on the system, an adaptive sliding mode controller (slow controller) with a disturbance observer is designed to track the trajectory of the flexible manipulator. In the fast time scale, in order to eliminate the influence of the unmodeled dynamics and the vibration state on the slow time scale on the controller design, a robust sliding mode controller is designed to suppress the flexible vibration. Finally, the slow controller and the fast controller are combined by using the singular perturbation theory to achieve the dual control goals of trajectory tracking and vibration suppression. Experimental results show that the method has strong robustness and good control effect.

Description

technical field [0001] The invention relates to the technical field of control of flexible manipulators, in particular to a combined sliding mode motion control method of a flexible manipulator. Background technique [0002] The development of advanced manufacturing technology puts forward higher requirements on the performance of robots, and various lightweight materials are continuously applied to the manufacturing of robots. Due to the advantages of light weight, wide detection range and fast operation speed, the flexible manipulator has become a current research hotspot. However, the existence of flexibility greatly reduces the structural damping of the system, which inevitably brings about flexibility vibration problems during the movement. If flexible vibration cannot be effectively suppressed, it is easy to reduce the trajectory tracking and control accuracy, and even cause resonance to cause system failure. Therefore, the study of the motion control problem of the ...

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Problems solved by technology

The experimental results show that using the singular perturbation method to design the controller has a good control effect, but most of them do not consider the influence of external disturbances and parameter uncertainties on the system, and the anti-interference ability is poor

Moreover, most of the methods are based on the Assumed-mode method and use the first two modes to describe the vibration of the flexible manipulator, without considering the impact of high-order modes and the slow vibration state of the decomposition process on the system design

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