Combined sliding mode motion control method of flexible mechanical arm

Abstract

The invention discloses a combined sliding mode motion control method of a flexible mechanical arm. Under multiple time scales, the motion control problem of the flexible mechanical arm with disturbance and system uncertainty is researched. Because the flexible mechanical arm has a multi-time-scale characteristic, a controller designed by applying a traditional method is easy to cause an ill-conditioned numerical value problem, and based on a singular perturbation theory, the flexible mechanical arm is modeled into a singular perturbation system with singular perturbation parameters and decomposed into a fast subsystem and a slow subsystem which describe rigid body motion and flexible vibration. Under the slow time scale, with consideration of the influence of external disturbance and parameter uncertainty on the system, a self-adaptive sliding mode controller (slow controller) with a disturbance observer is designed to track the trajectory of the flexible mechanical arm. Under a fasttime scale, a robust sliding mode controller is designed to achieve flexible vibration suppression in order to eliminate the influence of vibration states and the like under an unmodeled dynamic scaleand a slow time scale on the design of the controller. Finally, the slow controller and the fast controller are combined by using a singular perturbation theory to realize a dual control target of trajectory tracking and vibration suppression. The test results show that the method is high in robustness and good in control effect.

Description

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

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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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