Research On Key Technologies Of UAV Flight Control System Simulation Platform

Simulation technology plays an important role in the research and test of UAV flight control systems. However, in the traditional flight control systems simulation, there are many difficulties in the transition stage from digital simulation to hardware-in-the-loop simulation (HILS), such as information communication and large amounts of codes. Aiming at this problem, based on RTAI-Lab tool chain and embedded real-time Linux, a simulation platform is constructed in this paper.Firstly, digital simulation platform has been built. It consists of flight control simulation model and flight simulation model. Based on the principle of finite state machine, flight control simulation model is established by Stateflow. In the background of UAV dynamic model, flight simulation model is established by Simulink. In addition, different contributions to the external forces acting upon the rigid body in the stage of launching have been analyzed in theory, and the improved dynamic model by adding an analysis to the process of rocket falling off has been built.Secondly, rapid control prototyping development enviroment has been realized using Host-Tatget mode. With Linux kernel 2.6 and RTAI, the operation system is built on CF card for Target PC. On Host PC, RTAI-Lab tool chain is constructed, which acts as the software environment for the rapid flight control prototyping.Thirdly, rapid flight control prototyping simulation platform has been built. Using Stateflow RTW target, Stateflow Coder completes RTAI-Linux target code generation for flight control simulation model. The program of real-time serial communication is developed in user space under LXRT and embedded in the RTAI-Linux target code, which solves the problem of accessing data between RTAI-Linux target code and flight simulation PC.The simulation platform realizes automatization for developing the simulation system. It has the characteristics of fast, extendible, low cost, and so on, which are satisfied with the requirement of the UAV flight control simulation system.