Robust self-adaptive fault-tolerant control method based on non-affine and nonlinear unmanned aerial vehicle

Abstract

The invention provides a non-affine and nonlinear fault-tolerant controller design method for a non-affine and nonlinear system with disturbance and parameter uncertainty. The designed observer can be applied to the nonlinear system with non-affine parameters, and the observer has ideal robustness in the presence of the parameters of large-range variation. Fault information and disturbance information are hidden in the observer. A fault-tolerant controller is dynamically designed based on the observer. Due to the fact that the system is the non-affine and nonlinear system, the design of the controller is not easy. The invention provides the dynamic non-affine and nonlinear approximation method. The non-affine and nonlinear system is approximated into an affine nonlinear system with time-varying parameters. Parameters which need to be known are estimated online through a filter. A non-affine flight control system is used to verify the effectiveness of the provided method. The robust fault-tolerant control of the non-affine and nonlinear system can be realized.

Description

technical field [0001] The invention relates to the field of aircraft attitude fault-tolerant control, in particular to a robust adaptive fault-tolerant control method based on non-affine nonlinear unmanned aircraft. [0002] Background technique [0003] At present, model-based nonlinear control has made great progress in theory and application, such as feedback linearization, sliding mode control, inversion control, etc. Because adaptive technology can estimate unknown parameters online, it is widely used in combination with many nonlinear control methods to design fault-tolerant control. However, adaptive control requires the estimated parameters and control inputs to be in the affine form, that is, the uncertain parameters and control inputs must be in the explicit form, or the relationship with the state variables is a linear relationship. In the flight control system, the commonly used method is to linearize near the trim point. If the current state quantity and cont...

AI Technical Summary

Problems solved by technology

Some existing reconfigurable controllers for non-affine nonlinear systems have certain shortcomings. The commonly used inverse system method needs to find the inverse of the system model. Although some literature has proved that a controllable system must have its inverse, but Finding an inverse system is not an easy task, as the control inputs are implicit in the sine and cosine functions

Therefore, some literature proposes a non-affine controller design method, but the biggest disadvantage of this method is that it will increase the order of the system.

The literature designs a non-affine controller based on the method of time-scale separation, but the disadvantage of this method is that it is difficult to effectively combine the method with the existing adaptive technology and sliding mode technology.

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