Research On Restricted Characteristics Analysis And Control Methods Of Six-DOF Motion Platform

The flight simulator is a simulation device which is used to simulate the flight procedure of an aircraft.It is widely used in the field of flight training and aviation research.The six-DOF motion platform is used as the movement mechanism of the flight simulator.Due to the limited working space of the motion platform,the true motion of the aircraft cannot be reproduced directly.Therefore,dynamic simulation washout algorithm is introduced to control the actual flying motion of the aircraft within the limited workspace.Classical washout algorithm has the advantages of a simple structure and fast execution speed,but there are also defects such as fixed parameters and false hints.In order to improve the motion performance and the simulation fidelity of the simulator,it is important to optimize and improve the washout algorithm.In this paper,it is built the kinematics model of the six-DOF motion platform using the coordinate transformation approach.The solving process of the inverse solution is deduced.The simulation model of inverse kinematics is established in SIMULINK.The results show the movement law curve of each drive rod,and the motion characteristics of the platform is summarized.The reliability of the model is proved by simulation experiments.By studying the classical washout algorithm,it can be found that the filter parameters have a large effect on the washout results.Therefore,the filter parameters in the classical algorithm are optimized based on the genetic algorithm.The perception difference between the pilot actual perception in flight and the simulator provided by the simulator is taken as an objective function,combined together with the relevant constraints.The optimal filter parameters are searched by using the GA tool in MATLAB.The comparison results before and after the optimization show that genetic algorithm improves the dynamic fidelity of the simulator to some extent.The fixed parameters of the classical algorithm cause false cues and return to the neutral position slowly.In order to overcome the defects of the classical algorithm,a fuzzy optimization washout algorithm is proposed on the basis of genetic algorithm to achieve real-time adjustment of the filter parameters;The particle swarm optimization algorithm is used as a defuzzification method to get the accurate values of the parameters.The optimized algorithm is simulated in MATLAB/SIMULINK.The simulation results proved that the optimization algorithm can overcome the short comings of classical washout algorithm and improve the space utilization of the motion platform.