Underwater hydraulic mechanical arm nonlinear robust control method based on expansion observer

Abstract

The invention discloses an underwater hydraulic mechanical arm nonlinear robust control method based on an expansion observer. The method comprises the steps that a system nonlinear dynamic model of the underwater hydraulic mechanical arm is established; a nonlinear robust control law of the underwater hydraulic mechanical arm is established, and a nonlinear robust controller of the underwater hydraulic mechanical arm is obtained; an expansion observer of the underwater hydraulic mechanical arm is established, and an angular velocity observation value and an unmeasurable time-varying disturbance variable observation value of the underwater hydraulic mechanical arm are obtained; and the angular velocity observation value, the unmeasurable time-varying disturbance variable observation value and a tracking error value obtained through measurement of a sensor are fed back to the nonlinear robust controller in real time, the nonlinear robust controller controls the underwater hydraulic mechanical arm, and a complete underwater hydraulic mechanical arm closed-loop control system is formed. Effective control of the nonlinear robust controller on the underwater hydraulic mechanical arm under the condition of no angular velocity sensor is achieved. The problem that an existing control method is not high in control precision of the underwater hydraulic mechanical arm is solved.

Description

technical field [0001] The invention belongs to a nonlinear control method of a mechanical arm in the field of motion control of an underwater hydraulic mechanical arm, and in particular relates to a nonlinear robust control method of an underwater hydraulic mechanical arm based on an expansion observer. Background technique [0002] With the continuous deepening of ocean development, utilization and research, the complexity of underwater operation tasks is increasing, and its requirements for operation accuracy are also getting higher and higher. A job task is a row plan. As an important component of underwater robots, underwater hydraulic manipulators are necessary equipment to complete complex underwater operations. At present, it has been applied in many aspects such as pipeline tracking, submarine cable burial, marine resource investigation, submarine oil platform detection, underwater salvage and rescue diving and lifesaving. However, the current control method of un...

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Problems solved by technology

At the same time, the model uncertainty (modeling error and parameter uncertainty) and uncertain nonlinearity (mechanical friction, hydraulic oil resistance and wave current) on the control accuracy of the end of the manipulator, so as to further improve the robustness and accuracy of the control system of the underwater hydraulic manipulator, and solve the problem that the control accuracy of the existing control method for the underwater hydraulic manipulator is not high The problem

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