一种双回路VCE加速控制计划优化方法研究

Research on Variable Cycle Engines Acceleration Control Schedule Optimization Based on a Dual-loop Structure

摘要:

为提高变循环发动机加速性能,提升推力的响应速度,提出了内外回路耦合的加速控制计划优化方法。在内回路,以增加乘法层的神经网络状态空间模型在线构建预测模型,采用交替方向乘子法对约束条件下的闭环控制变量进行优化。在外回路,采用樽海鞘链群智能算法,以推力响应最快为目标,优化由贝塞尔曲线构造的开环控制规律。内回路的优化基于外回路开环几何机构的调节规律展开,外回路的优化以内回路的推力响应为评价,形成内、外回路耦合优化结构。以最优个体对应的发动机输入输出构造基于换算油气比的加速控制计划以及开环几何机构控制计划,开展加速过程的仿真验证。结果表明,在线学习预测模型5步预测最大动态误差低于0.8%；相比原有控制计划,优化后的控制计划充分利用了开、闭环控制变量的有利耦合,加速过程中,转速的响应时间缩短14.6%以上,推力响应时间缩短15%以上,验证了所提出的控制计划优化方法的有效性。

Abstract:

To improve the acceleration performance of variable cycle engines, and enhance the response speed of the thrust, an acceleration control schedule optimization method based on the coupled internal and external loops is proposed. In the inner loop, the neural network state space model with an additional multiplication layer was used to construct the prediction model online, and the alternating direction multiplier method was used to optimize the closed-loop control variables under constraint conditions. In the external loop, the salps swarm optimization algorithm was used to optimize the schedule of the open-loop control variables constructed by Bessel curve. The optimization of the inner loop was carried out based on the regulation law of the open-loop geometric mechanism, and the optimization of the external loop was evaluated by the thrust response of the inner loop, which formed a coupled optimization structure. The acceleration control schedule of corrected fuel-air ratio and the open-loop geometric mechanism are constructed based on inputs and outputs of the engine corresponding to the optimal individual, and the acceleration simulation was carried out to verify the acceleration schedule. The results show that the maximum 5-step output prediction error of the online learning prediction model is less than 2% in the dynamic process. Compared with the original control schedule, the optimized acceleration control schedules makes full use of the favorable coupling of the open and closed loop control variables, and in the acceleration process, the response time of the rotational speed is shortened by more than 14.6, and the response time of the thrust is shortened by more than 15%, which verifies the effectiveness of the proposed control schedule optimization method.