Design Of An Embedded Controll System For 3 DOF Helicopter Based On ARM

3-DOF helicopter can be used for semi-physical simulation and performance testing of flight control system, and be applied to simulate pitch helicopter that is in a state of tilting autogiro helicopter. The system is a typical multi-input -multiple-output control system with the characters of non-linear and strong cross-coupling, which is much complex object in the control system. By using 3-DOF helicopter as the research object, this paper adopts control theory and embedded system design method, then puts forward the embedded control system of the 3-DOF helicopter. The main research works list as below:1. Model building and Control theory Research of the 3-DOF helicopterBased on available technical information, this paper compiled 3-DOF helicopter mathematical model. It then took pitch channel for example, based on the Linear model, and established a non-linear mathematical model to be more close to the actual situation. The paper presented the GA parameter tuning method and control performance simulation under the application of the digital PID control method, the non-linear PID control performance simulation, discussed the various problems which might be encountered in the simulation process of the two kinds of control methods, and then compared the two simulation results which show adjustment time and overshoot of the non-linear control is superior to linear control.2. Design and Realization of the 3-DOF helicopter embedded systemThis paper developed the whole project of the embedded control for 3-DOF helicopter, and analyzed the physical characteristics of 3-DOF helicopter interface signals. Based on this, the paper realized the three-DOF helicopter linear and nonlinear control by means of using "EasyARM1138 +μC/OS-Ⅱ" and "Mico2440 +μC/OS-Ⅱ", which are two kinds of embedded hardware and software platform programs. Both of them can realize the accurate control of 3 DOF helicopter's elevation angle and pitch angle, whose directive signals are sent by an external flight rocker. And the two schemes can also simulate the three operation mode of practical helicopter which are'assistant operation of man','fully automatic driving of helicopter', and'keeping the helicopter at a horizontal level'. Targeting the defect that development board for the first scheme has no graphical display, the second scheme realized graphical display in the embedded development board, so that made the 3-DOF helicopter control completely out of computer.3. Control system debugging method of the 3-DOF helicopterThis paper presented three ways to debug the system, mainly using the LabVIEW as the auxiliary debug tool during the system development process, and conducted jointed test for the entire control system, which successfully acquired the parameter variations in the debug process, and provided reasonable basis for accurately calculating the control performance index. Through debugging and calculating the actual performance of the platform, it proved that the response time, overshoot, and stability have better effect than the linear control when the system using non-linear control.