Design Of Hardware-in-the-loop Simulator For Flight Control System

Along with the development of science and technology of the aviation, flight control system becomes more and more complicated, and the testing and verification of flight control system also becomes more vital than before. For consideration of safe verification, various parameters of the flight control system can not be verified directly in the real aircraft, so it is particularly important to use simulation technology to verify the flight control system. This paper presents the realization of the hardware-in-the-loop simulator for flight control system. Comparing hardware-in-the-loop simulation with the mathematical simulation, the reliability and authenticity of simulation enhanced. Comparing with the physical simulation, the flexibility of simulation was improved and the development fund was saved. The hardware-in-the-loop simulator compared with the special hardware-in-the-loop simulator, the generality increased but cost decreased.First, this paper analyzes the basic principle of hardware-in-the-loop simulation and presents the basic structure of hardware-in-the-loop simulator. According to the different system tasks, the tasks were distributed to the host computer and the target computer. To ensure the real-time of simulation, the target computer in the simulation adopts a high-performance real-time operating system called VxWorks. The host computer adopts Simulink which is well known among developers to construct the system model.Second, the hardware and software structure of the simulation computers were planned and designed. Considering the overall performance and development costs, the hardware resources was listed, and the performance of every card was introduced in this paper.Third, the card driver under VxWorks and Simulink driver module were developed. By modifying the MATLAB's RTW, the compilation of Simulink model was achieved and the real-time code which can be downloaded and run in the VxWorks was generated. The storage and upload of local data was realized with the help of software of target computer. The real-time monitoring software design was achieved by VC++ in the host computer. The controlling of tasks in the target computer was realized by this software which monitors and records the specific variables. It is convenient to analyze various parameters of the flight control system.After testing, development of the card drivers and Simulink diver modules achieved the desired performance requirements. The model can be compiled correctly by the modified RTW, and the generated real-time code after compilation can operate in VxWorks system correctly. The adjustable simulation step is able to meet different requirements of simulation. The real-time monitoring software can realize variables monitoring and data storage. As a whole, the design of the simulator is stable and reliable.