基于终端滑模的四旋翼飞行器非线性轨迹跟踪控制

Nonlinear trajectory tracking control of quadrotor helicopter based on terminal sliding mode

摘要:

考虑到四旋翼飞行器的传统内外环控制策略依赖时标分离假设,稳定性分析复杂,并且控制参数选取困难的缺点,提出了一种与传统内外环控制策略不同的轨迹跟踪控制器。首先将四旋翼飞行器数学模型进行相应的变换,以分解为高度、偏航角和纵横向三个级联的子系统,再使用终端滑模控制方法设计高度和偏航角子系统的控制器,使两个子系统的状态误差可以在有限时间内收敛到原点,之后基于变量非线性变换设计纵横向子系统的控制器,分析了闭环系统稳定性,证明了所设计的轨迹跟踪控制器可以保证闭环系统跟踪误差渐近稳定到原点,最后仿真实验的结果验证了所设计的控制器的有效性。

Abstract:

Considering that the traditional inner-outer loop control strategy of quadrotor helicopter depends on the time-scale separation assumption, the stability analysis is complex and the selection of control parameters is difficult, a trajectory tracking controller which is different from the traditional inner-outer loop control strategy is proposed. Firstly, the mathematical model of quadrotor helicopter is transformed to be three cascaded subsystems: altitude, yaw angle and vertical-horizontal subsystems. Then, terminal sliding mode control method is used to design the controller of altitude and yaw angle subsystems, so that the state errors of the two subsystems can converge to the origin in a finite time. Then, the vertical-horizontal subsystem is designed based on nonlinear variable transformation The stability of the closed-loop system is analyzed. It is proved that the designed trajectory tracking controller can ensure that the tracking error of the closed-loop system is asymptotically stable to the origin. Finally, the simulation results verify the effectiveness of the proposed controller.