位置和速度受限的微型无人直升机轨迹跟踪控制器

Trajectory tracking controller for miniature unmanned helicopters with position and velocity constrains

针对微型无人直升机在狭窄空间中的轨迹跟踪问题,设计了一种可以限制直升机位置和速度的跟踪控制器.首先将直升机的模型简化为一个未建模的动态模型.基于简化模型利用受限反步法设计控制器,其中在位置控制回路用障碍李雅普诺夫函数代替传统的纯二次型李雅普诺夫函数,以此来限制直升机的位置和速度;用指令滤波器对反步过程中虚拟控制的导数进行估计,避免了复杂的解析计算.此外,将未建模动态和指令滤波器误差合并成有界扰动项,并设计了自适应算法对扰动的上界进行估计和补偿.稳定性分析证明了直升机的闭环跟踪误差最终一致有界,且位置和速度始终位于预设的限制集合中.仿真结果验证了该控制器的有效性.

A trajectory tracking controller with position and velocity constraints is developed for miniature unmanned helicopters flying in narrow space. The helicopter model is firstly simplified to one with unmolded dynamics. Based on this model, the constrained backstepping technique is applied to design the controller, in which the barrier Lyapunov functions,instead of traditional pure quadratic Lyapunov functions, are introduced to the position control loop for maintaining the position and velocity constraints. Command filters are utilized to estimate derivatives of the virtual controls during the backstepping progress such that complex analytical calculations can be avoided. Furthermore, upper bounds of the disturbances due to the unmodeled dynamics and command filter errors are estimated and compensated with adaptive algorithms.The stability analysis shows that tracking errors of the closed-loop helicopter system are ultimately uniformly bounded and its position and velocity are restricted in the prescribed sets during the tracking progress. Simulation results validate the effectiveness of the proposed controller.