In attitude control of quad-rotor aircraft,the conventional Proportion-Integration-Differentiation(PID) closed4 oop algorithm has the problems of complex parameter tuning,and large overshoot due to closed4 oop zero.According to the system dynamic performance requirements,and by improving the traditional PID control algorithm,an optimal PID algorithm with pre4 iltering performance is designed based on the time and the Integral Absolute Error(ITAE) indicators.Matlab-Simulink is used for making contrast experi...