动态负调约束下固体冲压发动机燃气流量控制算法研究

Gas Flow Control Algorithm of Solid Fuel Ramjet with Dynamic Negative Regulation Constraint

关键词:  固体冲压发动机  燃气发生器  燃气负调  跟踪微分器  自适应PI控制

Key words:  Solid fuel ramjet  Gas generator  Anti-regulation of gas flow  Tracking differentiator  Adaptive PI controller

摘要:

变流量固体冲压发动机工作过程中，常采用控制燃气发生器压强的方式调节燃气生成量，在跟踪变化压强指令过程中，流量会产生明显的负调现象，严重影响发动机系统的安全性和可靠性。为解决这一问题，以具有高度非线性、强时变特性的燃气发生器系统为对象，构建了基于粒子群算法的流量调节自适应PI控制器，并给出一种利用自适应微分跟踪器对期望控制指令进行“整形”的负调改善算法。首先，结合负调发生、终止判据，综合考量系统流量安全裕度，负调发生方向，构建了适配于动态负调约束的自适应跟踪微分器（TD），克服了传统跟踪微分器在负调抑制过程中控制精度不高，指向性不强等缺陷；进一步，开展了多工况下的负调抑制算法仿真校验。结果表明：所设计自适应控制算法具备良好的燃气流量控制能力，可实现在基本不改变响应时间情况下，将最大负调量削减56.6%的控制效果，展现出良好的工程应用前景。

Abstract:

During the working process of variable flow solid fuel ramjet， the gas generation amount is often adjusted by controlling the pressure of the gas generator. In the process of tracking the variable pressure instruction， an obvious anti-regulation phenomenon will be produced by the gas flow， which seriously affects the safety and reliability of the solid fuel ramjet system. Therefore， taking the gas generator system with high nonlinearity and strong time-varying characteristics as the object， this paper constructs an adaptive PI controller for flow regulation based on particle swarm optimization algorithm， and introduces an anti-regulation improvement algorithm that uses an adaptive tracking differentiator to ‘shape’ the desired control instructions. Firstly， an adaptive tracking differentiator （TD） adapted to dynamic anti-regulation constraints is constructed by combining the occurrence and termination criteria of anti-regulation， the safety margin of system flow and the occurrence direction of anti-regulation comprehensively， which overcomes the defects of low control accuracy and weak directivity of traditional tracking differentiator in the process of anti-regulation suppression. Furthermore， the simulation verification of the anti-regulation suppression algorithm under multiple conditions is carried out. The results show that the designed adaptive control algorithm has good gas flow control ability， and can achieve the maximum anti-regulation reduction of 56.6% without basically changing the response time. The control effect has a good engineering application prospect.