Adaptive Fault-Tolerant Control Method for Coordinated Drive of Lunar Exploration Vehicle Based on Hierarchical Fuzzy System

Abstract

The invention relates to a lunar rover coordinated drive self-adaption fault-tolerant control method based on a hierarchical fuzzy system. According to the method, a fault-tolerant controller is designed according to faults of an actuator on the situation that uncertainty and external disturbances exist in the system. The method includes the steps that an expectation value of a wheel slip ratio is given; a change range of a wheel in a dynamic process is limited according to the expectation value of the slip ratio; a bounded function of an unknown function of the system is given; a bounded function of an unknown failure function and a bound of an unknown disturbance item are given; a domain and a membership function of an input variable of the fuzzy system of each layer are given; a hierarchical fuzzy logical system approximates an unknown function; an adaptive law of a parameter vector is designed; a hierarchical fuzzy fault-tolerant controller is designed. The method enables the number of fuzzy rules to be greatly reduced and facilitates real-time control; control precision before a fault and control precision after a fault are high, and steady state time is short.

Description

technical field [0001] The invention relates to the technical field of automatic control, in particular to a layered fuzzy system-based self-adaptive fault-tolerant control method for coordinated driving of a lunar exploration vehicle. Background technique [0002] In the lunar exploration project, the lunar exploration vehicle plays an extremely important role. The lunar exploration vehicle is the carrier of various detection instruments, and its basic function is to have the ability to walk on complex roads in unknown environments. Much of the Moon's surface is covered with fine dust and debris called regolith. From the perspective of physical characteristics, most of the soil in the lunar regolith layer is relatively soft, and there are many small sandstones distributed. This soil condition poses a great challenge to the autonomous driving of the rover. To perform scientific exploration tasks in such a complex terrain environment, the lunar rover must have a control sys...

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Problems solved by technology

Since the driving control system of the lunar exploration vehicle has multiple input variables, it is well known that when dealing with systems with multiple input variables, there is a general difficulty in using fuzzy control: the number of rules in the fuzzy controller is exponential with the number of system variables growth, that is, the "curse of dimensionality" problem, which seriously reduces the real-time performance of the control, making it difficult to implement in engineering

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