A Study On The Method Of Dimensional Synthesis For Less Degree Of Freedom Flight Simulation Platform

In flight simulator the parallel motion platform is an important component.The traditional Stewart motion platform has high simulation performance with the help of 6 DOF.But,at the same time it also have some shortcomings,such as high cost,complex structure and difficult to control.However the less freedom of parallel motion platform is better.In this paper,we study the problem of lack of simulation fidelity for less DOF flight simulation platform,the process of solving workspace of the parallel manipulator is cumbersome and how to synthesize the organization according to the design needs.A new less DOF motion cueing simulation algorithm,the method of determine best workspace and how to do the dimensional synthesis according to the optimal workspace is proposed.Get the conclusion of the cueing algorithm has good simulation fidelity,the optimal workspace can circling most trajectories and it is effective to dimensional synthesis according to the workspace.The main research contents are as follows:1.Kinematics modeling and analysis of the less DOF motion platform.First determine the types of simulation motion platform is the 3-PRS parallel manipulator,including motion platform,static platform and 3-PRS branch.Then build the coordinate system and the kinematic model,the kinematic inverse solution and the Jacobian matrix are solved for the mechanism,get the speed Jacobian mapping relationship.2.A new less DOF motion cueing simulation algorithm is proposed and simulated.Firstly,based on to the human body to stimulate the principle of dynamic stimulation of the vestibular perception system model.Secondly,according to the classical motion cueing algorithm and the moving speed of the parasitic motion and the Euler angular velocity transfer matrix,a new motion cueing algorithm can be applied to the three DOF simulation platform.Finally,a simulation model of the new algorithm is established in MATLAB/Simulink,and the simulation is carried out to verify its validity.3.The method of solving the optimal working space of the moving platform is studied.First,the actual flight data as the motion cueing algorithm input,and get the movement trajectory of platform.Secondly,the circling ellipse of the trajectory is obtained by thestatistical principle and the variable step search boundary method.Finally,all the parameters of the circling ellipse are integrated to solve the circling ellipsoid of the motion space.4.The scale of the simulation motion platform is studied synthetically.Select the design variables,evaluation indicators and constraints,and establish the objective function of scale optimization.According to the motion platform workspace and design variable parameters,the simulation optimization of the motion platform and the degree of dexterity as the index.