A review of modeling,simulation,and control technologies of altitude ground test facilities for control application

As the pivotal test equipment of aero-engines design,finalization,improvement,modification,etc.,the Altitude Ground Test Facilities(AGTF)plays an important role in the research and development of the aero-engines.With the rapid development of advanced high-performance aeroengine,the increasing demand of high-altitude simulation test is driving AGTF to improve its test ability and level of automation and intelligence.The modeling method,simulation tool,and control technology are the key factors to support the improvement of the AGTF control system.The main purpose of this paper is to provide an overview of modeling methods,simulation tools,and control technologies in AGTF control system for future research.First,it reviews the evolution of AGTF in the world,from the early formative stage to integration stage.Then,the mathematical modeling method of AGTF for control application is overviewed.Furthermore,the simulation tools used in the AGTF control system are overviewed from numerical simulation to hardware-in-loop simulation and further to semi-physical simulation.Meanwhile,the control technologies used in the AGTF control system are summarized from single-variable control to multivariable integrated control,and from classical control theory to modern control theory.Finally,recommendations for future research are outlined.Therefore,this review article provides extensive literature information for the modeling,simulation,and control design of AGTF for control application.

μ-Synthesis control with reference model for aeropropulsion system test facility under dynamic coupling and uncertainty

Due to the dynamic coupling and multi-source uncertainties,it is difficult to accurately control the pressure and temperature of the Aeropropulsion System Test Facility(ASTF)in the presence of rapid command and large disturbance.This paper presents the design ofμ-synthesis control to solve the problem.By incorporating the pressure ratio into the linear equation of the control valve,the modeling error of ASTF in the low frequency range is effectively reduced.Then,an uncertain model is established by considering various factors,including parameter variations,modeling error in the low frequency range,unmodeled dynamics,and changes in the working point.To address the dynamic coupling,a diagonal reference model with desired performance is incorporated intoμ-synthesis.Furthermore,all weighting functions are designed according to the performance requirements.Finally,theμ-controller is obtained by using the standardμ-synthesis method.Simulation results indicate that theμ-controller decouples the pressure and temperature dynamics of ASTF.Compared with the multivariable PI controller,integral-μcontroller,and double integral-μcontroller,the proposedμ-controller can achieve higher transient accuracy and better disturbance rejection.Moreover,the robustness of theμ-controller is demonstrated by Monte Carlo simulations.

Two freedom linear parameter varying μ synthesis control for flight environment testbed

To solve the problem of robust servo performance of Flight Environment Testbed(FET)of Altitude Ground Test Facilities(AGTF) over the whole operational envelope, a two-degree-offreedom μ synthesis method based on Linear Parameter Varying(LPV) schematic is proposed, and meanwhile a new structure frame of μ synthesis control on two degrees of freedom with double integral and weighting functions is presented, which constitutes a core support part of the paper. Aimed at the problem of reference command's rapid change, one freedom feed forward is adopted, while another freedom output feedback is used to meet good servo tracking as well as disturbance and noise rejection; furthermore, to overcome the overshoot problem and acquire dynamic tuning,the integral is introduced in inner loop, and another integral controller is used in outer loop in order to guarantee steady errors; additionally, two performance weighting functions are designed to achieve robust specialty and control energy limit considering the uncertainties in system. As the schedule parameters change over large flight envelope, the stability of closed-loop LPV system is proved using Lyapunov inequalities. The simulation results show that the relative tracking errors of temperature and pressure are less than 0.5% with LPV μ synthesis controller. Meanwhile, compared with non-LPV μ synthesis controller in large uncertainty range, the proposed approach in this research can ensure robust servo performance of FET over the whole operational envelope.

Modified robust optimal adaptive control for flight environment simulation system with heat transfer uncertainty

To solve the rapid transient control problem of Flight Environment Simulation System(FESS) of Altitude Ground Test Facilities(AGTF) with large heat transfer uncertainty and disturbance, a new adaptive control structure of modified robust optimal adaptive control is presented.The mathematic modeling of FESS is given and the influence of heat transfer is analyzed through energy view. To consider the influence of heat transfer in controller design, we introduce a matched uncertainty that represents heat transfer influence in the linearized system of FESS. Based on this linear system, we deduce the design of modified robust optimal adaptive control law in a general way. Meanwhile, the robust stability of the modified robust optimal adaptive control law is proved through using Lyapunov stability theory. Then, a typical aero-engine test condition with Mach Dash and Zoom-Climb is used to verify the effectiveness of the devised adaptive controller. The simulation results show that the designed controller has servo tracking and disturbance rejection performance under heat transfer uncertainty and disturbance;the relative steady-state and dynamic errors of pressure and temperature are both smaller than 1% and 0.2% respectively. Furthermore,the influence of the modification parameter c is analyzed through simulation. Finally, comparing with the standard ideal model reference adaptive controller, the modified robust optimal adaptive controller obviously provides better control performance than the ideal model reference adaptive controller does.

Extended State Observer based Attitude Control of a Bird-like Flapping-wing Flying Robot

The attitude control system of a flapping-wing flying robot plays an important role in the precise orientation and tracking of the robot.In this paper,the modeling of a bird-like micro flapping-wing system is introduced,and the design of a sliding mode controller based on an Extended State Observer(ESO)is described.The main design difficulties are the control law and the adaptive law for the attitude control system.To address this problem,a sliding mode adaptive extended state observer algorithm is proposed.Firstly,a new extended state approximation method is used to estimate the final output as a disturbance state.Then,a sliding mode observer with good robustness to the model approximation error and external disturbance is used to estimate the system state.Compared with traditional algorithms,this method is not only suitable for more general cases,but also effectively reduces the influence of the approximation error and interference.Next,the simulation and experiment example is given to illustrate the implementation process.The results show that the algorithm can effectively estimate the state of the attitude control system of the flapping-wing flying robot,and further guarantee the robustness of the model regarding error and external disturbance.