基于摆线运动的黄瓜采摘机器人终端滑模轨迹跟踪控制

黄瓜采摘机器人是机器人技术在农业中的具体应用，而快速稳定地到达目标采摘点的轨迹规划则是黄瓜采摘机器人研究的主要内容之一。根据摆线运动曲线光滑，并能在有限区间的端点产生零速度和零加速度的特点，将其应用于黄瓜采摘机器人关节空间的轨迹规划，该方法计算简单，实时性好。同时，为了实现对期望轨迹的精确跟踪，构造了一种快速非奇异的终端滑模控制器，采用指数和幂次结合的趋近率方法，引入非线性滑模面，突破了普通滑模控制器在线性滑模条件下渐进收敛的特点，并且不会出现传统终端滑模控制的奇异性和抖振问题。李亚普诺夫稳定性分析和仿真试验证明：它能够准确的跟踪期望轨迹，并能使位置跟踪误差在有限时间内收敛到零，响应时间短，跟踪效果好。

Trajectory tracking with terminal sliding mode control of cucumber picking robot manipulator based on cycloidal motion

Cucumber picking robot is the concrete application of robot technology in agriculture. Trajectory planning which enables cucumber picking robot to reach the picking target fast and stably is one of the most important research contents of cucumber picking robot. The cycloidal motion, which has the properties of continuity and zero velocity and acceleration at the ports of the bounded interval, was proposed as a feasible approach to plan trajectory in joint space of robot manipulator. Moreover, in order to achieve precise tracking of the desired trajectory, a fast and non-singular terminal sliding mode controller with the approaching law combining exponent with power function was constructed. Compared with linear sliding mode surface, it exhibits some superior properties such as fast and finite time convergence by adopting non-linear sliding mode surface. In addition, it also possesses the advantages of non-singularity and chattering-free as compared with conventional terminal sliding mode. The robustness of the controller is verified with Lyapunov stability theory. Theoretical analysis and simulation experiments show that faster and higher precision tracking performance was obtained by using the presented algorithm.