LPV Robust Controller Design with Regional Pole Assignment for an Aero-Engine

基于区域极点配置的航空发动机LPV鲁棒控制器设计

¹ School of Power and Energy, Northwestern Polytechnical University, Xi'an 710072, China
² School of Astronautics, Northwestern Polytechnical University, Xi'an 710072, China
³ Beijing Power Machinery Institute, Beijing 100074, China

Received: 2 November 2018

Abstract

The aerodynamic characteristics of aero-engine, which have a wide range of flight envelopes, vary drastically, so its controller is required to be able to adapt to a large range of parameter variations and have good robustness. To solve the above problem, based on the regional pole assignment, a new aero-engine multi-variable robust gain scheduled LPV control algorithm was proposed. Firstly, the Jacobian linearization method was used to obtain polynomial LPV model of aero-engine, which can describe its dynamic performance under certain conditions. Further, aiming at the polynomial LPV model, a LPV output feedback controller with the closed-loop system pole placement in a given region, which satisfied robust H_∞ performance requirement, is designed using the LMI method. Then the grid method is used to transform the Lyapunov functional which depend on the scheduling parameters into a single Lyapunov function, which can guarantee the system has good steady performance. Finally, simulation studies have carried out based on a certain turbofan engine. The simulation results show that the designed controller can realize the accurate tracking of control commands with response time less than 1.6 s, over shoot less than 1% and steady-state tracking error less than 0.1%. The control system can guarantee the global stability and has good robustness in the design envelope.

摘要

针对航空发动机飞行包线内复杂热力循环参数引出的多变量鲁棒增益调度控制下的参考指令动态跟踪问题，提出了一种基于区域极点配置的多变量LPV鲁棒变增益控制方法。利用雅克比线性化方法建立发动机多项式LPV模型，用于描述发动机在一定条件下的动态性能。然后根据上述模型，基于线性矩阵不等式的区域极点配置方法，提出具有H_∞鲁棒性能的LPV输出反馈控制器设计方法。通过将闭环系统的极点配置在所期望的位置，以满足控制系统的动态性能。采用网格法将依赖于调度参数的Lyapunov函数转化为常值Lyapunov函数并理论上保证系统稳定性。以某型涡扇发动机为研究对象进行仿真验证，仿真结果表明：与未加入区域极点配置的LPV控制器相比，基于极点配置的设计方法使控制系统具有更好的动态响应特性。同时，该方法实现了对控制指令的精确跟踪，系统阶跃响应的调节时间不超过1.6 s，超调不大于1%，对控制期望的稳态跟踪误差在0.1%以内，符合发动机控制系统技术要求。