Research On Six-Degree-of-Freedom Motion Simulation Of Hybrid Structures

Flight simulation system plays an important role in military and civilian fields.Flight simulation system has the advantages of high confidence,low cost and high repeatability,so the application of flight simulation system based on motion simulator is becoming more and more extensive.However,the general motion simulator is influenced by the structure and algorithm,which makes the simulation system differ greatly from the actual situation,which affects the credibility of the simulation system.Based on this,a six-degree-of-freedom motion simulation platform of hybrid structure is developed,which can be used to simulate the six-dimensional motion attitude of airborne aircraft.By analyzing the six-degree-of-freedom distribution structure,the position-positive and negative solution of six-degree-of-freedom motion simulator is deduced.In this paper,the causes and characteristics of the crawling phenomenon of the electric servo in the low speed state are studied.Aiming at the static and dynamic friction model,a model reference adaptive algorithm based on the dynamic friction model is proposed to estimate the friction force,Friction force as the main body of the inertia error caused by the control accuracy error,improve the system control and operation accuracy.The research results of the paper provide a good reference scheme for the design,development and optimization of the 6-DOF motion simulation system of the hybrid structure and the adaptive control technology in the flight simulation platform system,and have good engineering application reference value.Aiming at the problem that the traditional six-degree-of-freedom motion simulator structure is more complex and has low accuracy under low-speed condition,the paper first analyzes the structure scheme of six-degree-of-freedom motion simulation system from the three structures of series structure,parallel structure and mixed structure and then analyzes the influence of the mixed structure on the positive and negative solutions of the system position,and provides a theoretical basis for the construction of the structural scheme and the construction of the prototype platform.Taking into account the structural characteristics of each module and each other,the paper deduces and establishes the output model of each corresponding module,and designs a single module control scheme based on traditional PID control.In the case of attitude and position control,Dynamic characteristics,steady-state error and other parameters.In this paper,the concrete control function is obtained by frequency domain analysis and the method is verified by simulation results.Aiming at the problem of crawling in the low speed state and the smaller speed range available in the motion simulation system under the traditional PID control,this paper presents a model based on the double motor drag configuration and the model reference based on the LuGre dynamic friction model adaptive control method,the former through the DC motor and AC motor docking drag to expand the available speed range,the latter through the friction model information real-time estimates,not only improve the control position accuracy,but also reduce the nonlinear friction on the system control the impact of performance.The method is validated by simulation experiment.In order to test the performance of the structural system in the actual situation,the physical platform of the 6-DOF motion simulation of the hybrid structure is constructed.Based on the simulation experiment of the control algorithm,the experimental data are used to verify the LuGre model effect of adaptive control technology on control performance of 6-DOF motion simulation platform.The research of the paper provides a good reference scheme for the design,development and optimization of the 6-DOF motion simulation system of the hybrid structure,and the improvement of the adaptive control technology in the flight simulation platform system,and has good reference value for engineering application.