Research On Dynamic Characteristics Of Electric Load Simulator

The load simulator is a semi-physical simulation device that can simulate the load torque received by the aircraft steering gear in an indoor environment and test the performance of the steering gear.Because of high loading accuracy,fast response,easy operation,etc.,it is widely used in weapons guidance,scientific research experiments,aerospace and other fields.Due to the constraints of machining accuracy,lubrication conditions,installation accuracy,etc.,the stiffness,inertia,clearance,and friction factors will affect the loading performance of the system.As the mechanical structure develops toward lighter weight,the parts are prone to elastic deformation during the movement,and the elastic deformation of the parts directly affects the loading performance of the entire system.In order to understand the dynamic characteristics of the electric load simulator,it is important to study the effects of stiffness,inertia,clearance and friction on the dynamic characteristics of the electric load simulator,and select appropriate methods to suppress or eliminate the influence of these factors.The paper establishes the 3D model of the electric load simulation torque transmission system.By the finite element method,the frequency of the corresponding vibration modes and first six modes are analyzed,and the maximum deformation in the torque transmission system is obtained.According to the working principle of the system and the characteristics of nonlinear factors,mathematical models including stiffness,inertia,friction and clearance are established.The influence of these factors on the loading performance of the electric load simulator is deeply studied and analyzed.Based on the structural optimization design aspect,the optimal stiffness and inertia of the system were analyzed and determined.In order to suppress the influence of friction and clearance,the feed-forward compensation algorithm based on LuGre friction model and the gap inverse model compensation algorithm are used to suppress the influence of friction and clearance on the system,thus improving the dynamic performance of the electric load simulator.Finally,the rationality of the optimal stiffness and inertia,the effectiveness of the gap compensation algorithm and the friction compensation algorithm are verified by simulation experiments.The research shows that the weak link of the system is obtained by modal analysis for the dynamic characteristics of the system structure.The optimal stiffness and inertia based on structural optimization design,the feed-forward compensation algorithm based on LuGre friction model and inverse gap model compensation algorithm are proposed for the optimization of system dynamic characteristics.The research results have certain reference for the optimization of the dynamic characteristics of the future electric load simulator.