基于双阀调节的稳压腔开环-闭环复合控制方法

Open Loop-Closed Loop Compound Control Method for Pressure Stabilizing Chamber Based on Double-Valve Control

关键词:  双阀控制  试验台  复合控制  跟踪微分器  开环控制

Key words:  Double-valve control  Test facility  Compound control  Tracking differentiator  Open loop control

摘要:

为保障大型空气管路试验台的整体性能，采用双阀调节的稳压腔系统实现压力的精准控制，提出了一种基于双阀调节的稳压腔开环-闭环复合控制方法。首先，构建包括蝶阀开环控制和套筒阀闭环控制的虚拟控制器，通过放气总流量将虚拟控制器和稳压腔组合，建立稳压腔开环-闭环复合控制结构。其次，依据该控制结构设计控制器，其中开环控制器引入跟踪微分器用以求解压力变化率并规划指令压力的过渡过程，基于此，根据容腔压力微分方程计算蝶阀放气流量，进而考虑蝶阀动态并反求蝶阀液压缸位移指令；依据稳压腔线性模型、套筒阀模型构建闭环控制回路，并设计闭环PI控制器。最后，开展伺服跟踪性能及抗干扰性能的仿真验证，其中，压力阶跃响应的超调量为0.89%，稳态误差低于0.03%，外界干扰流量大范围变化的情况下，稳压腔压力波动低于0.5%，压力偏差低于0.75kPa，表明本文提出的方法能够有效协调蝶阀和套筒阀的动作，实现稳压腔的压力精准控制。

Abstract:

In order to ensure the overall performance of large-scale air pipeline test facility， the pressure stabilizing chamber with double-valve is required to achieve accurate pressure control. Therefore， an open loop-closed loop compound control method for pressure stabilizing chamber based on double-valve control is proposed. Firstly， a virtual controller is constructed， which includes the open-loop control of the butterfly valve and the closed-loop control of the sleeve valve. The virtual controller and the pressure stabilizing chamber are combined through the total discharge flow to establish an open loop-closed loop compound control structure. Secondly， the controller is designed according to the control structure， and a tracking differentiator is introduced into the open loop controller to solve the pressure change rate and plan the transition process of the command pressure. Based on this， the discharge flow of the butterfly valve is calculated according to the chamber pressure differential equation， and hydraulic cylinder displacement command is obtained by considering the dynamics of the butterfly valve. The closed-loop control loop is constructed based on the linear model of the pressure stabilizing chamber and the sleeve valve model. And the closed-loop PI controller is designed. Finally， the simulation verifications of servo tracking performance and anti-interference performance are carried out. The overshoot of the pressure step response is 0.89%， the steady state error is less than 0.03%. The pressure fluctuation of the chamber is less than 0.5% when the external interference flow varies widely， and the pressure deviation is less than 0.75kPa. The simulation results show that the method proposed in this paper can effectively coordinate the actions of the butterfly valve and the sleeve valve， and realize the precise control of the pressure of the chamber.