具有未知输入干扰的观测器设计

DESIGN OF OBSERVERS FOR SYSTEM WITH UNKNOWN INPUTS

提出一种全阶比例积分观测器。该观测器包含有估计误差的比例和积分回路 ,可同时得到状态和未知输入估计。分析了比例积分观测器的结构和估计性能 ,给出并证明了其存在条件 ,由于存在条件弱于未知输入观测器 ,该比例积分观测器可以更广泛地应用于基于观测器的技术方案。通过一个飞行器线性化模型 ,进行了比例积分观测器设计。仿真结果表明 ,比例积分观测器的估计性能优于常规

A full order PI observer is proposed for linear continuous systems with unknown inputs appearing in both process and measurement, which is an extension of the PI observers for systems with only unknown plant disturbance. The PI observer has two feedback loops, a proportional loop and an integral loop of the estimation error; in this way, the PI observer can estimate not only the states but also the unknown inputs. The structure and the estimation performance of the PI observer are discussed and analyzed, and the conditions are given and proved. Owing to the weaker assumptions than UIO (Unknown Input Observers), it can be applied by more observer based technical solutions. The design method is declared and carried out with illustrative examples of the linearized dynamics of the L 1011 aircraft. The comparison between estimation performance of the PI observer and Luenberger observer shows the better performance of the former.