四旋翼无人机吊挂飞行减摆控制

Anti-swing Control of Quadrotor UAV with a Slung-Load

针对四旋翼无人机吊挂飞行系统存在模型偏差及外界干扰带来的位置跟踪和减摆控制难的问题,提出了一种基于补偿函数观测器的非线性控制方法。首先,建立了四旋翼无人机吊挂飞行系统动力学模型,并设计了补偿函数观测器对未建模动态和未知扰动进行观测;然后,针对系统参考输入跟踪误差约束,构建了障碍Lyapunov函数来设计反步控制器,并在控制器中引入补偿函数观测器的估计值对系统总扰动进行补偿,保证了无人机位置误差和负载摆角在约束范围内变化,使系统能够达到预期控制效果。Lyapunov稳定性分析证明了闭环系统的稳定性、位置误差的收敛和摆动的抑制。仿真结果表明,设计的控制器在对无人机位置精确控制的同时,能有效抑制吊挂负载的摆动。

To solve the problem that model bias and external disturbances increase the difficulty of position tracking and anti-swing control of the slung-load flight system of quadrotor UAVs a nonlinear control method based on compensation function observer is proposed.Firstly the dynamic model of the slung-load flight system of a quadrotor UAV is built and a compensation function observer is designed to observe the unmodelled dynamics and unknown disturbances.Then in view of the tracking error constraints of system reference inputs a barrier Lyapunov function is built to design a backstepping controller and the total disturbance is compensated for by introducing the estimation value of the compensation function observer in the controller thus ensuring the UAV position errors and the slung-load swing angle to change within the constraint ranges and making the system achieve the expected control effect.Lyapunov stability analysis proves the stability of the closed-loop system the convergence of position errors and the suppression of slung-load swing.The simulation results show that the proposed controller can effectively suppress the swing of the slung-load while realizing the accurate control of UAV positions.