Research Of Four Rotor Aircraft Flight Control System

Quadrocopters as a way to achieve vertical takeoff and landing unmanned aircraft,especially for tasks in the near surface environment. In the military, unmanned aircraft can be used for surveillance and reconnaissance, combat assessment, electronic jamming and other military tasks. In civilian drones can be used in highway patrol, exploration and mapping,aerial photography, transportation management, forest fire prevention and rescue. Many advantages of Quadrocopters, making it become a research hotspot.The traditional quadrocopters control system has a controller poor stability, low precision attitude problem solver. In this system, in order to effectively solve the above problems,respectively, in terms of both hardware and software improvements.First, the hardware circuit design: As traditional flight control board, chosen mostly ARM7 processor architecture as the control platform, the processor can achieve a simple control algorithm processing performance when performing poorly. This paper built a DSP-based processor(TMS320F28335) as the core of the aircraft control system. The processor not only in the stability of the structure than the ARM7 processor has greatly improved, and the processor is integrated floating-point unit, can effectively improve the accuracy of the solution. Meanwhile, in the peripheral circuit design in a short circuit reset. To prevent obstructions when a short circuit caused the aircraft flight control board burned.Second, the software design: just a few traditional four-element method for data update and attitude solution according to the gyroscope data. But in practice often deviation gyro navigation system accuracy cannot reach the allowable range. Therefore, this paper quaternion self-compensation algorithm, the output of accelerometer and electronic compass as a reference point, at every quaternion update on quaternion compensate. Meanwhile, in the control algorithm applied cascade PID controller design instead of the original single-level PID controller. On the interference suppression disturbance, has been greatly improved.Finally, build the solution algorithm and four-rotor aircraft attitude control algorithm algorithm test platform. Solver algorithms were tested for flight control algorithms and gesture. Experimental results show that the application of the attitude solution, flight control algorithms effectively improve the four-rotor aircraft under the premise of stability, improveposture solver accuracy.