Research And Hardware Verification Of Active Disturbance Rejection Control For The Variable Cycle Engine

The variable cycle engine(VCE)has complex structures,changeable cycle modes,strong nonlinear characteristics,and operates in a wider flight envelope.It is of great significance to study the problem of the VCE disturbance suppression under the influence of subsystem coupling between multiple control loops,engine performance degradation,model uncertainty,and external disturbances.In order to realize multivariable disturbance rejection control of the VCE,and solve the problem of the performance degradation of the extended state observer caused by the high frequency sensor noise,this thesis relies on the project of”Research and Verification of the Multi-variable Control Algorithm of an Engine”.Aiming at a certain type of the VCE,this thesis carrys out research on improved extended state observer,and multivariable active disturbance rejection control design and hardware-in-loop verification.The main contents are as follows:(1)Aiming at the problem that it is difficult to directly determine the control loop caused by many control variables of the VCE,this thesis studies the selection of the control variables and the controlled variables of the VCE based on the relative gain array.By calculating the relative gain,the fuel to high pressure speed and the tail nozzle area to engine pressure ratio are determined as the main closed-loop control loop.Then,considering the large range of the flight envelope of the VCE,it is necessary to design the controller parameters in a divided manner.This thesis divides the flight envelope of the VCE by calculating the gap metric of the linear model under typical operating point.(2)Aiming at the problem that the traditional single-pole configuration method in the ex-tended state observer cannot take into account the noise suppression and anti-disturbance perfor-mance,a double-pole configuration method is proposed.The frequency domain and impulse re-sponse performance of the observer under the double-pole and single-pole methods are analyzed.The observation performance of the double-pole extended state observer under the condition that the observer model does not match the actual model is studied.In the bounded input bounded output stability framework,the stability condition of the observer is given,and the observation error caused by the determined model mismatch is given.It is proved that the observation error caused by model mismatch is bounded,and increasing the observer bandwidth w_ocan reduce the observation error caused by model mismatch.(3)Aiming at the coupling between variables caused by the complex structure of the VCE,the external disturbance,the internal disturbance,an active disturbance rejection controller based on a double-pole observer is designed.It is verified by simulation that the controller still has a satisfying control effect under external disturbance and mode switching disturbance.Aiming at the problem that the control effect of a single controller parameter is not satisfying under a wide envelope,a gain scheduling active disturbance rejection control method is designed,and a performance index function is given to evaluate and verify the performance of the designed gain scheduling controller.(4)In order to verify the real-time performance and control quality of the ADRC designed for the VCE,a hardware-in-the-loop experimental platform is built based on NI PXIe8840,NI PXIe8431 and other hardware environments.The controller model is packaged and configured by software such as MATLAB and NI Veri Stand,and the hardware-in-loop verification of the multivariable ADRC for the VCE is completed.The results demonstrate the real-time perfor-mance of the controller under the control period of 10ms,as well as the steady state and dynamic response effects that meet the actual needs of the project.