Performance Based Switching Control And Its Application In Aero-engine Control Simulation

As a research focus in the field of control,switching control has been increasingly applied to practical control problems.The development of aero-engine is extremely difficult.At the same time,as the national major scientific research project,the design of aero-engine control systems has attracted more and more investigators on the subject of control.A method based on regional pole placement is used to study the output feedback H? control problems of the switched linear system,in order to improve the performance of the system.The existence condition of the output feedback H?controller is described in the form of linear matrix inequalities,and the results are applied to the simulation model of aero-engine.The contents are described as follows:First of all,according to a linear time-invariant external disturbance switched system,the performance index is analysed,and the linear matrix inequalities are constructed aiming to place the closed-loop poles of each system into a same assigned circular region.And the existence condition of the output feedback stabilization controller is given on the basis of these conditions.Since the solution of each loop shares a common Lyapunov function,the designed system can guarantee the stability requirements in the method of arbitrary switching.Then,taking advantage of the test model and data of a turbofan engine,the results are applied to the.simulation of single loop and multiple loops with the switching law of minimizing the fuel flow.The experiments which constrain the existence range of the circular region is conducted first,and a range of constraining the circular region is found for making the system response time and overshoot satisfied.Then the simulation results of single loop and multiple loops are compared.The results show that the proposed method of multiple loops can not only guarantee the dynamic performance of the system,but also reduce the gain of the closed-loop system,and can effectively restrain the robustness of the system.Then,according to the linear time-invariant switched systems with the external disturbance,an output feedback H? stabilization controller is designed for each subsystem.By constraining the location of the poles into the new assigned sector region,the contradiction between the convergence speed.and the constraints of the system is compromised.And the results are also described in the form of linear matrix inequalities.A switching law depending on the state is also designed.The small deviation linearization model is established with the method of approximate linearization at the equilibrium point.The simulation is based on the small deviation linearization model of aero-engines and the test data of a type of turbofan engine.The switching simulation selects two typical loops of temperature protection loop and acceleration loop,and the results are compared with the single loop controller speed output.The simulation results show that the performance of the switched system with the designed switching law is better than that of each system using single loop controller.And the performance is more prominent for reducing the overshoot of a system.There are few results combining regional pole placement,control method and switching control method to design a controller in the previous studies.The researches giving the design method of the switching law and displaying the aero-engine control simulation examples are also very few.The proposed controllers apply the switching control and regional pole placement to the design of the output feedback H?stabilization controller in order to improve the performance of the system.