为了充分发挥固体火箭冲压发动机的性能,构造了进气道不起动保护等裕度控制方法。首先,通过进气道稳态模型来预估进气道不起动边界,即获取不同来流条件下进气道能够承受的最大背压。而后,通过壅塞流动的特征求取壅塞截面参数,并采用零维守恒方程得到进气道出口参数和不起动裕度,从而建立火箭冲压发动机计算模型。最后,采用不起动等裕度控制策略构造双环TD-PID控制器通过调节燃气发生器压强,进而对进气道的不起动裕度加以控制,使得进气道在能够起动的前提下发挥发动机的最优性能。仿真结果表明:对于方波形式的不起动裕度指令,与原始PID控制器相比,TD-PID控制器能够更加快速地收敛至设定值,且稳态相对误差由0.04%降至0.003%,加之燃气流量的最大相对负调量仅为2.4%,验证了该方法的有效性。

In order to fully explore the performance of the solid rocket ramjet engine,an equal-margin control method for inlet unstart protection was constructed in this paper.Firstly,the inlet unstart boundary was estimated by the steady state model of the inlet to obtain the maximum backpressure that the inlet can withstand under different flow conditions.Then,the parameters of the choked cross section were obtained by using the characteristics of the choked flow,and the inlet outlet parameters and unstart margin were obtained by using the zero-dimensional conversion equation,thus the computational model of the rocket ramjet engine was established.Finally,a unstart equal-margin control strategy was adopted to construct the double loop TD (Tracking differentiator)-PID controller to take control of the inlet unstart margin through adjusting the pressure of the gas generator,so that the optimal performance of the engine can be achieved while avoiding the inlet unstart.The simulation results show that for the square wave unstart margin command,the TD-PID controller can converge to the set value more rapidly,and reduce the steady-state relative error from 0.04% to 0.003% compared with the original PID controller,and the maximum relative negative regulation of gas flow is only 2.4%,which proves the validity of the method.