Design Of Motion System For Four-degree-of-freedom Flight Simulator Composite Platform

In recent years,the civil aviation industry has developed rapidly and gradually entered the mass market.With the popularity of the flight,the demand for experiencing flight has also increased.The motion system is one of the hot topics of flight simulator researches.Currently,most motion systems adopt a six-degree-of-freedom parallel platform.However,its disadvantages,such as high price,small range of motion,large space occupation,and difficult control calculation,have hindered the popularity of the simulator.In order to solve the aforementioned drawbacks,the writer of this disertation aims to design a new four-degree-of-freedom composite platform with the advantages of low price,large range of motion,small space occupation,simple and flexible control and to compute and simulate its three-dimensional structure,kinematics,dynamics and control systems.The product will be mainly used in flight similation clubs,science museums,exhibitions and other places in the future.Firstly,the flight simulation equipment standards and technical indicators are summarized through authoritative documents such as civil aviation regulations,and the performance index and preliminary design scheme of the four-degree-of-freedom flight simulator composite platform are proposed.Secondly,design and calculate the detailed structure of the platform and drawing of its three-dimensional model,the use of ANSYS Workbench software to analyze the strength of each part under static load and dynamic load respectively and the maximum impact load that the platform could bear.Thirdly,kinematics analysis of the platform is expounded,the platform's coordinate system is established by D-H connecting rod parameter method,and the system of forward and inverse kinematics are solved by homogeneous transformation method and Euler method respectively.The mathematical model of platform is constructed by MATLAB Robotics Toolbox software,simulation to verify the correctness of the kinematic equation.The trajectory planning and workspace calculation of the platform,as well as the trajectory and reach of the end effector of the platform are obtained.The feasibility of the design and the correctness of the simulation are also verified.Fourthly,dynamic analysis of the platform is expounded,including the analysis of platform coupling relationship,derivation of coupled dynamic equations,the establishment of platform dynamics equation by Lagrangian method,inertia simulation and modal analysis of platform using MATLAB Robotics Toolbox and ANSYS Workbench software respectively.The inertia curve is used to verify the existence of the platform coupling phenomenon.The vibration modes and natural frequency characteristics of each order provide theoretical basis for control optimization.Finally,the automatic control system of this platform is designed,the double-closed-loop PID control of the pitch and roll modules is modeled by MATLAB Simulink software.The ideal response curve is obtained by adjusting the PID parameters.The correctness and feasibility of the platform's control system model is verified.The foregoing calculation simulation lays a theoretical foundation for the actual construction of the platform.