旋翼飞行机械臂固定时间滑模控制

Fixed-Time Sliding Mode Control of Rotor Flight Manipulator

针对旋翼飞行机械臂轨迹跟踪控制中的不确定性和扰动问题,提出了一种基于固定时间滑模观测器的滑模控制算法。首先,在广义坐标系下建立了旋翼飞行机械臂运动学与动力学模型,并设计出固定时间观测器对模型参数不确定性与外部扰动进行估计,通过在滑模中引入分段函数和饱和函数抑制固定时间观测器的抖振,加快其收敛速度。随后,将旋翼飞行机械臂划分为位置、姿态以及机械臂3个子系统,基于固定时间理论,分别对3个子系统设计了新型固定时间滑模控制器,并设计自适应趋近律以抑制滑模控制器的抖振。与传统滑模控制器相比,该控制器具有更快的收敛速度与更好的跟踪性能。利用Lyapunov稳定性理论证明了系统的稳定性。最后通过仿真实验验证了所提算法的有效性,该算法对旋翼飞行机械臂轨迹跟踪控制具有较好效果。

A sliding mode control algorithm based on fixed-time sliding mode observer is proposed for the trajectory tracking control of rotor flight manipulator with self-modeling uncertainties and external disturbances.Firstly,the kinematics and dynamics models of the rotor flight manipulator are established in the generalized coordinate system,and a fixed-time observer is designed to estimate the uncertainties of the model parameters and the external disturbances.The piecewise function and the saturation function are introduced into the sliding surface to suppress the chattering of the fixed-time observer and speed up its convergence.Then,the rotor flight manipulator is divided into three subsystems,that is position,attitude and manipulator.Based on the fixed-time theory,a new fixed-time sliding mode controller is designed for the three subsystems respectively,and an adaptive reaching law is designed to suppress the chattering of the sliding mode controller.Compared with the traditional sliding mode controller,this controller has faster convergence speed and better tracking performance.The stability of the system is proved by Lyapunov stability theory.Finally,the effectiveness of the proposed algorithm is verified by simulation experiments,and it has good effects on the trajectory tracking control of the rotor flight manipulator.