Coordinated trajectory planning of homogeneous and heterogeneous mobile robots in collision avoidance scenarios

Abstract

Abstract The transformation of existing production and logistics halls into flexibly configurable factories requires the ability of autonomous mobile robots to navigate efficiently in an unstructured and changing environment. Conflicting situations between several robots due to collision avoidance when moving close to each other can be resolved via the central control system or in a distributed manner. In this paper, we address distributed coordinated trajectory planning of mobile robots with communication to efficiently resolve collision avoidance scenarios without a central control unit. We simulatively investigate coordinated planners that solve optimal control problems with a sliding time horizon. Further, the planners differ in whether a centralized optimal control problem in the coupled state space of the robots or multiple decentralized optimization problems in the state space of one robot are formulated. From another point of view, the methods vary in a cooperative or non-cooperative property which manifests itself in the consideration or neglection of the other vehicles’ intentions within the cost function. Further, we not only consider homogeneous mobile robots that are modeled by the same vehicle model and the same parameterization but also heterogeneous robots with different physical limitations and dimensions. We present simulation results of symmetric and non-symmetric collision avoidance scenarios with 2–8 mobile robots. As a comparison criterion, we use the average duration until all vehicles have reached their destinations. The results show that the cooperative planners resolve homogeneous scenarios and the non-cooperative planners resolve heterogeneous ones involving vehicles having different dimensions with a lower average scenario duration.