An Attitude Tracking Control Method for Vertical Takeoff and Landing Reusable Vehicle Based on Fixed Time Convergence Observer

Abstract

The invention relates to a vertical takeoff and landing reusable launch vehicle attitude tracking control method based on a fixed time convergence observer, which belongs to the technical field of aircraft control. The method derives an attitude tracking error state equation based on a reentry coordinate system, all modeled and unmodeled dynamics of the system except a control moment are treated as system disturbances, converting to a second-order double-integral state equation is carried out, and the complexity of the system is further simplified.

Description

technical field [0001] The invention relates to an attitude tracking control method of a vertical take-off and landing reusable vehicle based on a fixed-time convergence observer, and belongs to the technical field of aircraft control. Background technique [0002] In recent years, the vertical take-off and landing reusable vehicle has gradually been valued by commercial aerospace companies around the world due to its low cost, strong maintainability, multiple reusability and high safety, and has invested a lot of Human and material resources have been correspondingly researched and developed. Among them, the more famous commercial aerospace companies mainly include foreign SpaceX, BlueOrigin, Masten, McDonnell Douglas and domestic LinkSpace, LandSpace and OneSpace. Many vertical take-off and landing reusable vehicles such as DC-X, New Glenn, Falcon 9 and New Line 1 have been designed one after another, and only SpaceX's Falcon 9 rocket has achieved more than 10 successful ...

AI Technical Summary

Problems solved by technology

The adaptive dynamic surface control method is based on the pre-designed dynamic surface model, so that the state quantity slides on the sliding surface to ensure the attitude tracking performance. However, the convergence time of the sliding surface is unknown. It is difficult to ensure fast attitude convergence under the condition of large attitude deviation, and there is still a certain steady-state tracking error

However, the adaptive fuzzy Hinf control method needs to design corresponding complex fuzzy logic in advance, which has poor adaptability to large disturbances and strong nonlinear characteristics in the actual flight process, and cannot guarantee that the attitude error will converge to zero within a fixed time.

Adaptive dynamic inverse generally adopts a dual-loop control mode, divides the system into two sub-modules, a fast loop and a slow loop, and designs the control laws separately, finally obtains the virtual control torque command, and then distributes the control commands, so its attitude tracking accuracy is limited. Slow convergence speed and poor anti-interference ability

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