Nikou Alexandros, Heshmati-Alamdari Shahab, Dimarogonas Dimos V
Division of Decision and Control, School of Electrical Engineering and Computer Science, KTH Royal Institute of Technology, 100 44 Stockholm, Sweden.
Auton Robots. 2020;44(8):1451-1467. doi: 10.1007/s10514-020-09937-6. Epub 2020 Jul 31.
This paper presents a scalable procedure for time-constrained planning of a class of uncertain nonlinear multi-robot systems. In particular, we consider robotic agents operating in a workspace which contains regions of interest (RoI), in which atomic propositions for each robot are assigned. The main goal is to design decentralized and robust control laws so that each robot meets an individual high-level specification given as a metric interval temporal logic (MITL), while using only local information based on a limited sensing radius. Furthermore, the robots need to fulfill certain desired transient constraints such as collision avoidance between them. The controllers, which guarantee the transition between regions, consist of two terms: a nominal control input, which is computed online and is the solution of a decentralized finite-horizon optimal control problem (DFHOCP); and an additive state feedback law which is computed offline and guarantees that the real trajectories of the system will belong to a hyper-tube centered along the nominal trajectory. The controllers serve as actions for the individual weighted transition system (WTS) of each robot, and the time duration required for the transition between regions is modeled by a weight. The DFHOCP is solved at every sampling time by each robot and then necessary information is exchanged between neighboring robots. The proposed approach is scalable since it does not require a product computation among the WTS of the robots. The proposed framework is experimentally tested and the results show that the proposed framework is promising for solving real-life robotic as well as industrial applications.
本文提出了一种可扩展的方法，用于对一类不确定非线性多机器人系统进行时间约束规划。具体而言，我们考虑在包含感兴趣区域（RoI）的工作空间中运行的机器人代理，其中为每个机器人分配了原子命题。主要目标是设计分散且鲁棒的控制律，使得每个机器人在仅基于有限传感半径的局部信息的情况下，满足作为度量区间时态逻辑（MITL）给出的个体高级规范。此外，机器人需要满足某些期望的瞬态约束，例如它们之间的碰撞避免。保证区域之间转换的控制器由两项组成：一个标称控制输入，它是在线计算的，并且是分散有限时域最优控制问题（DFHOCP）的解；以及一个离线计算的附加状态反馈律，它保证系统的实际轨迹将属于以标称轨迹为中心的超管。控制器作为每个机器人的个体加权转移系统（WTS）的动作，并且区域之间转换所需的持续时间由权重建模。每个机器人在每个采样时间求解DFHOCP，然后在相邻机器人之间交换必要信息。所提出的方法是可扩展的，因为它不需要在机器人的WTS之间进行乘积计算。所提出的框架经过了实验测试，结果表明该框架在解决实际机器人以及工业应用方面很有前景。
