Design Of Autopilot For Unmanned Airship Based On RT-Linux

Compared with fixed-wing vehicles, unmanned airship has manyadvantages. It can ensure long endurance of station-keeping atgeostationary position. The special requirement of unmanned airship’sautopilot includes more input and output interfaces, heavy data processingtasks, integration with pressure and buoyancy control. It should support thestation-keeping and other flight control mode. And its control method israther different from that of conventional fixed-wing vehicles. Traditionalforeground-background mode is a simple development mode, but itsefficiency is low. Also, the implementation of sustainable development isdifficult. Operation system has a reliable support for the hardware platformand device interfaces. And it has good scalability and portability. In orderto develop the sustainable autopilot platform of unmanned airship, thestable and reliable real-time operation system is very necessary.This paper focuses on the design for the embedded unmannedairship’s autopilot based on ARM hardware platform and RT-Linuxoperation system. First of all, according to the special requirement, theoverall scheme of autopilot was designed, including the hardware platform,the servo controller and the related software system. Then, the development of device drivers for integrated sensors and external deviceswas conducted. Next, on the basis of the application of the RT-Linuxoperation system, the U-Boot guidance procedure, RT-Linux operationsystem and root file system were transplanted into the autopilot platform.Finally, autopilot’s task queue and its real-time tasks scheduling wasstudied, and the scheduling policy for the hybrid of periodic and aperiodicreal-time tasks was improved and verified in the RT-Linux operationsystem.