四旋翼无人机预设性能自适应PID控制

Quad-rotor Unmanned Helicopter Presets Performance Adaptive PID Control

针对四旋翼飞行器在轨迹跟踪过程中存在建模误差和外界干扰问题,设计了一种双闭环控制系统。内环姿态环采用自适应PID算法,用滑模算法作为自适应机制,结合梯度下降法克服传统PID需要手动调节参数的问题,并用RBF神经网络消除滑模控制过程中产生的抖振现象;外环位置环采用预设性能自适应PID算法,即在自适应PID算法的基础上加上预设性能控制,将误差用预设性能函数进行转换,使系统误差能够始终稳定在预设值,实现位置的快速跟踪;最后用Lyapunov函数证明系统的稳定性。从跟踪的快速性、稳定性和稳态性能方面,由仿真结果对比证明本文所设计的控制算法有很大的优越性,并能对不同形式的外部扰动表现出强抗干扰性。

A dual closed-loop control system is designed to address the problems of modelling errors and external interference in the trajectory tracking process of the quadrotor.The inner loop attitude loop adopts an adaptive PID algorithm,using sliding mode control as the adaptive mechanism,combined with the gradient descent method to overcome the problems of traditional PID manual parameter adjustment,and using RBF neural network to eliminate the jitter array phenomenon generated in the process of sliding mode control.The outer loop position loop adopts an adaptive PID algorithm based on preset performance,that is,on the basis of the adaptive algorithm plus preset performance,the error is converted by the preset performance function.This enables the system error to be stabilized at the preset value and enables fast tracking of the position.Finally,the stability of the system is demonstrated by the Lyapunov function.From the aspects of tracking rapidity and stability.In terms of tracking speed,stability and steady-state performance,the simulation results prove that the designed control algorithm has great advantages and can show strong anti-interference against different forms of external disturbance.