Liu Hongyan, Qu Daokui, Xu Fang, Du Zhenjun, Jia Kai, Liu Mingmin
State Key Laboratory of Robotics, Shenyang Institute of Automation, Chinese Academy of Sciences, Shenyang 110016, China.
Institutes for Robotics and Intelligent Manufacturing, Chinese Academy of Sciences, Shenyang 110169, China.
Entropy (Basel). 2022 May 6;24(5):653. doi: 10.3390/e24050653.
With the rapid development of robot perception and planning technology, robots are gradually getting rid of fixed fences and working closely with humans in shared workspaces. The safety of human-robot coexistence has become critical. Traditional motion planning methods perform poorly in dynamic environments where obstacles motion is highly uncertain. In this paper, we propose an efficient online trajectory generation method to help manipulator autonomous planning in dynamic environments. Our approach starts with an efficient kinodynamic path search algorithm that considers the links constraints and finds a safe and feasible initial trajectory with minimal control effort and time. To increase the clearance between the trajectory and obstacles and improve the smoothness, a trajectory optimization method using the B-spline convex hull property is adopted to minimize the penalty of collision cost, smoothness, and dynamical feasibility. To avoid the collisions between the links and obstacles and the collisions of the links themselves, a constraint-relaxed links collision avoidance method is developed by solving a quadratic programming problem. Compared with the existing state-of-the-art planning method for dynamic environments and advanced trajectory optimization method, our method can generate a smoother, collision-free trajectory in less time with a higher success rate. Detailed simulation comparison experiments, as well as real-world experiments, are reported to verify the effectiveness of our method.
随着机器人感知与规划技术的快速发展，机器人正逐渐摆脱固定围栏，在共享工作空间中与人类密切协作。人机共存的安全性已变得至关重要。传统的运动规划方法在障碍物运动高度不确定的动态环境中表现不佳。在本文中，我们提出了一种高效的在线轨迹生成方法，以帮助机械手在动态环境中进行自主规划。我们的方法首先采用一种高效的运动动力学路径搜索算法，该算法考虑连杆约束，并以最小的控制努力和时间找到一条安全可行的初始轨迹。为了增加轨迹与障碍物之间的间隙并提高平滑度，采用了一种利用B样条凸包特性的轨迹优化方法，以最小化碰撞成本、平滑度和动力学可行性的惩罚。为了避免连杆与障碍物之间的碰撞以及连杆自身的碰撞，通过求解二次规划问题开发了一种约束松弛的连杆碰撞避免方法。与现有的动态环境规划方法和先进的轨迹优化方法相比，我们的方法能够在更短的时间内以更高的成功率生成更平滑、无碰撞的轨迹。本文报告了详细的仿真比较实验以及实际实验，以验证我们方法的有效性。
