This paper investigates the online motion coordination problem for a group of mobile robots moving in a shared workspace, each of which is assigned a linear temporal logic specification. Based on the realistic assumptions that each robot is subject to both state and input constraints and can have only local view and local information, a fully distributed multi-robot motion coordination strategy is proposed. For each robot, the motion coordination strategy consists of three layers. An offline layer pre-computes the braking area for each region in the workspace, the controlled transition system, and a so-called potential function. An initialization layer outputs an initially safely satisfying trajectory. An online coordination layer resolves conflicts when one occurs. The online coordination layer is further decomposed into three steps. Firstly, a conflict detection algorithm is implemented, which detects conflicts with neighboring robots. Whenever conflicts are detected, a rule is designed to assign dynamically a planning order to each pair of neighboring robots. Finally, a sampling-based algorithm is designed to generate local collision-free trajectories for the robot which at the same time guarantees the feasibility of the specification. Safety is proven to be guaranteed for all robots at any time. The effectiveness and the computational tractability of the resulting solution is verified numerically by two case studies.
翻译:本文调查一组移动机器人在共享工作空间移动的一组移动机器人的在线运动协调问题, 每一个机器人都有线性时间逻辑规格。 基于每个机器人同时受到州和输入限制, 并且只能有本地视图和本地信息的现实假设, 提议了一个完全分布的多机器人运动协调战略。 对于每个机器人, 运动协调战略由三层组成。 一个离线层预先计算工作空间中每个区域的制动区、 控制过渡系统和一个所谓的潜在函数。 初始化层输出一个初步安全满足的轨迹。 一个在线协调层会在出现时解决冲突。 一个在线协调层将进一步分解为三步。 首先, 执行冲突探测算法, 检测与相邻机器人的冲突。 当发现冲突时, 规则旨在为每对相邻的机器人指定动态的规划命令。 最后, 一个基于取样的算法旨在为机器人生成一个本地的不发生碰撞的轨迹, 同时保证规格的可行性。 一个在线协调层会解决冲突。 首先, 一个在线协调层会进一步分解成三步。 首先, 执行一个冲突探测算法, 检测与相邻的机器人冲突。 一旦发现, 任何数字的计算, 将保证任何时间的计算结果的概率都得到保证。