Optimal Control of a Nonlinear Coupled Hydraulic-mechanical Aircraft Elevator System using Nonlinear Programming

摘要

This paper illustrates how the performance of a nonlinear hydraulic-mechanical elevator system can be optimized using nonlinear programming (NLP) and simulation tools, which are available in Matlab and Simulink. They can easily be used to solve optimal control problems with state constraints. The method is presented using the model of a hydraulic actuator which is used in positioning the elevator mechanism of the HL-20 crew rescue vehicle, which was developed at NASA Langley. SimMechanics and Sim Hydraulics are used in order to model the hydraulic circuit and elevator mechanism separately. These subsystems then are integrated in Simulink environment in order to simulate the model performance. Simulink response optimization toolbox is then used to perform the constrained optimization task including tuning a PI controller gains. Simulation results show that the proposed controller can improve the system response effectively.