分级燃烧循环发动机启动过程的变结构控制

Variable Structure Control in the Start Process for Staged Combustion Cycle Engine

针对分级燃烧循环液体火箭发动机启动过程的特点 ,提出了一种变结构控制系统。将启动过程的控制量分解为期望控制输入和随机反馈控制输入 ,后者由变结构控制律来确定。选择发动机涡轮泵转速、预燃室和燃烧室压力作为跟踪状态变量构造线性切换函数 ,采用分段的等速趋近率实现滑动模态控制。这种变结构控制结构简单且具有较强的鲁棒性 ,使发动机启动过程的稳定性增强。仿真研究验证了变结构控制系统的有效性。

A variable structure control system for the start up process of staged combustion cycle liquid rocket engine is presented in this paper. The control inputs of the engine system in start up process are divided into the predetermined elements and feedback control input, and the latter is decided by variable structure controlling law. The turbo pump rotate speed, pre burn chamber's pressure and main combustion chamber's pressure are chosen as control state variables which are utilized to construct a linear switch function, and a piecewise equal speed approach control law is used to implement the slide mode control of the engine. Since the scheme of the variable structure control is simple and it is robust to changing conditions of disturbance and uncertainty, the stability will be raised in the engine starting process. The simulation has shown the superior qualities of the variable structure control system.