A Design Of The Cheap&Simple Automatic Pilot Applicable To The Low-speed /small-scaled/nature-stability UAV

In the 21st centuries, because of owning the ability of automatic flight, the unmanned aerial vehicles (UAV) have been usually applied in military and economic fields. It has been practiced that the UAV is a kind of high-efficiency working platform in air. So, More and more attention is being paid to the potential value of UAV by more and more people. To promote the application of UAV, designing a type of automatic flight control system, which is low cost and easy to be operated, becomes an important way of research.For the UAV, which is low speed, small scaled and nature stability, not only the variety of aerodynamicist parameter, caused by the air compression, could be neglected, but also its pitch short period mode has good static and dynamic state characteristic. The type of airplanes have widespread foreground of public application, and are easily designed.The automatic pilot (AP) is the core device of the UAV's flight control system. Its function is to navigate and control the UAV. Its structure decides the choice and design of the UAV's sensors and machineries, and affects the manufacturing cost and the operation function of the UAV directly.The Global Positioning System (GPS) has a series of advantage,such as mature,low cost,all-weather,all-region,high accuracy,no position error margin backloging with time. It's suitable for the flight navigation of UAV.The UAV is a typical Multiple Input Multiple Output system. But,some passage of the UAV system could be simplifed into Single Input Single Output system in the actual processing. Therefore, it's a valid method to combine the Modern Control Theories with the Classical Control Theories in the design of the automatic pilot's control law.In this article, a new automatic pilot is designed. It adapts to the characteristics of the UAV, which is low speed, small scaled and nature stability, and is to be used controlling the UAV flying on the presumptive route. In the process of designing, with combining the Flight Dynamics theories, the State-Space method, the Root Locus method together, the flight control law is built up, in which there is a PID controller with two negative feedback loops. At the same time, the navigation methodology, which is based on the GPS with the compensation ofthe magnetic compass,is introduced.After all, just a little sensors and machineries, included a GPS receiver,a magnetic compass,an...