# Path Planning of Rail-Mounted Logistics Robots Based on the Improved Dijkstra Algorithm
## 1 Introduction
[PERSON] and colleagues rectified the flaw of the general Dijkstra algorithm, which only sorted the tags in the priority queue according to the ascending order of cost, and demonstrated the soundness of the method by induction by introducing the Bellman optimality principle. While our current research and the work conducted by [PERSON] et al. both aim to enhance the traditional Dijkstra algorithm and utilize it for the purpose of finding the shortest path, it is important to note that the approaches employed and the specific contexts in which they are applied differ. Currently, we propose the implementation of a real-time occupancy and time window conflict judgment model for each site. This model addresses the limitation of the traditional Dijkstra algorithm, which does not account for the time factor. Additionally, it enables multi-robot on-orbit anti-collision capabilities, thereby enhancing the efficiency of the algorithm. [PERSON] et al. proposed an enhancement of the Dijkstra algorithm that addresses the limitation of the traditional Dijkstra algorithm in searching for the shortest path in networks with discrete resources and continuous constraints [24]. Ultrawideband (UWB) positioning technology encompasses many methods that can be categorized based on distinct positioning criteria, namely Time Difference of Arrival (TDOA), Time of Arrival (TOA), and Angle of Arrival (AOA). The Chan method and Taylor algorithm are two well-established location algorithms that rely on Time Difference of Arrival (TDOA) measurements. The Chan algorithm aims to determine the posterior probability distribution function with the highest value, whereas the Taylor algorithm is computed based on the Hessian matrix. The approach proposed by [PERSON], which utilizesthe Time Difference of Arrival (TDOA), has gained significant popularity because of its computational efficiency and superior location accuracy [25]. This study utilizes the enhanced Dijkstra algorithm to address the challenges associated with global path planning and conflict coordination in a multi-robot system. The efficiency of the traditional Dijkstra algorithm can be enhanced by addressing the limitation of disregarding the time component through the introduction of the node real-time occupancy and time window judgment conflict model. The enhanced Dijkstra algorithm, which incorporates real-time node occupancy, enables the identification of all feasible shortest routes across various tasks. Additionally, the integration of the time window conflict judgment model mitigates route conflicts during the execution of multiple tasks, facilitating the planning of conflict-free shortest routes. Simultaneously, an innovative algorithm utilizing the Time Difference of Arrival (TDOA) and Channel (Chan) is implemented to enable real-time positioning of rail-mounted logistics robots within the workshop. The algorithm presented in this study aims to optimize path planning for multiple robots in large workshops, with the objectives of minimizing travel distance, reducing travel time, and minimizing the number of turns. Additionally, the algorithm is designed to effectively handle conflicts and efficiently complete multiple distribution tasks. The ultimate goal is to achieve automation and unmanned operations in material distribution within these large workshop settings.