【摘要】 高超声速飞行器再入段初期,所处大气环境空气稀薄,空气舵已无法提供足够力矩来维持姿态稳定,因此就需要反作用控制系统(Reaction Control System,RCS)来提供姿态稳定力矩。针对给定的飞行器RCS八喷管配置方案,基于查表法和脉宽调制,提出了一种能够维持飞行器系统姿态稳定的静态指令分配方法。给出了高超声速飞行器六自由度状态方程,采用一阶滑模控制算法进行姿态稳定控制;基于查表法思想和冲量等效的脉宽调制原理,完成了无故障情况下八喷管指令分配组合表的设计,并根据工程实际对组合表进行容错优化;设计了能够对单推力器发生卡死故障具有容错性的指令分配优化组合表,并采用脉宽调制方法对控制指令进行调制从而获得推力器的开关指令。仿真验证了该指令分配方法能够维持系统姿态稳定,提高控制系统的控制效率,有效解决了八喷管配置以及单喷管卡死故障情况下的指令分配问题。更多还原

【Abstract】 At the beginning of the reentry segment of the hypersonic vehicle,the air in the atmosphere is thin,and the air rudder cannot provide enough torque to maintain the attitude stability. Therefore,a reaction control system( RCS) is required to provide the attitude stabilization torque. For a given eight-nozzle configuration scheme,based on the table-lookup method and the pulse width modulation method,a static instruction allocation method capable of maintaining the attitude stability of the aircraft system is proposed. The six-degree-of-freedom state equation of hypersonic vehicle was given. Based on this,a first-order sliding mode control algorithm was used for attitude stabilization control. Based on the fault-tolerant control theory and the table-lookup method,the design of eight-nozzle command distribution combination table under fault-free condition was completed and the combination table was fault-tolerantly optimized according to the actual project. The instruction allocation optimization table that could tolerant the single thruster jamming fault was designed,and the modulation commands were modulated by pulse width modulation to obtain the thruster switching instructions. The simulation verifies that the instruction allocation method can improve the control efficiency of the control system and reduce the fuel consumption,and effectively solve the problem of command assignment under the condition of thruster failure.更多还原