基于控制分配的恒压腔压力精准控制

针对采用双阀调节的恒压腔系统压力在空气流量大范围变化时的精确控制问题，提出了一种基于控制分配的恒压腔压力精准控制方法。首先，建立了虚拟放气流量的双阀控制分配算法，包括：建立满足虚拟放气流量要求且调节阀能耗最小的优化问题；通过线性矩阵不等式(Linear Matrix Inequality, LMI)求解该优化问题得到双阀实际流通面积值；考虑调节阀动态并计算调节阀控制信号指令值。其次，建立以虚拟放气流量为恒压腔控制输入的闭环负反馈回路，基于此，设计满足伺服性能和抗干扰性能要求的PI控制器，引入上述双阀控制分配算法，进而构建完整的基于控制分配的恒压腔压力控制系统。仿真结果表明，采用该方法的控制系统性能明显优于传统单阀PI控制系统性能，恒压腔压力动态相对误差小于0.07%；干扰流量最大变化率为77kg/s2时，压力最大偏差低于500Pa；此外，调节阀动态时间常数和流量系数的拉偏仿真结果进一步验证了该控制器的鲁棒性。

Precise Pressure Control of Constant Pressure Chamber Based on Control Allocation

Aiming at precise pressure control of the constant pressure chamber adjusted by two valves when the air flow changes in a wide range, a precise pressure control method of constant pressure chamber based on control allocation is proposed. First, a control allocation algorithm of two valves for virtual discharge flow is established. The algorithm includes the following steps: establish an optimization problem that meets the requirements of the virtual discharge flow and minimizes the energy consumption of the regulating valves, solve the optimization problem by Linear Matrix Inequality (LMI) to obtain the actual opening area value of the double valves, consider the dynamics of the regulating valves and calculate its control signal command values. Second, the virtual discharge flow is used as the control input of the constant pressure chamber to establish a closed-loop negative feedback loop. Based on this, a PI controller that meets the requirements of servo performance and anti-interference performance is designed. Then, introduce the established control allocation algorithm to build a complete pressure control system based on control allocation. The simulation results show that the control performance of the proposed method is obviously better than the traditional PI control method of single valve. The dynamic relative error of the pressure is less than 0.07%. When the maximum change rate of interference flow is 77kg/s2, the maximum deviation of pressure is less than 500Pa. In addition, the uncertainties of the dynamic time constant and flow coefficient of the regulating valves are introduced, and the simulation results further verify the robustness of the controller.