# Comparison of Multi-Tracked Running Gears in Terms of Obstacle Negotiation Capabilities
## 1 Introduction
At the same time, appropriate parameters of the module and joint location can further increase these capabilities. In another study [21], it was highlighted that the use of the dual-tracked structure in robots allowed them to climb slopes that were 50% steeper than those that a single-tracked structure robot could climb. It was also indicated that the multi-tracked solution required a lower traction coefficient to overcome slopes than the classic solution. A further paper [38] describes the analysis of how a two-track passive solution with a common pitch axis was able to overcome obstacles. This paper draws attention to the ratio of the radius of the common axle wheels to the contact length of the tracks with the ground, which largely determines the height of the wall that could be overcome. There are also single-frame solutions with pivotally mounted track systems. In simulation studies [39], different types of lightweight UGV running gear systems were compared in terms of the average required driving torque and the magnitude of the trajectory tracking error when driving over uneven terrain profiles. Among wheeled and tracked solutions, multi-tracked systems proved to be the most advantageous in both criteria. The dimensions  
Figure 1: Multi-tracked platform body architecture schemes: (**a**) active articulated track system; (**b**) passive/active articulated track system; (**c**) passive articulated track system. of the multi-tracked design were optimized, enhancing its capabilities [40]. A study on the climbing ability of a passive multi-tracked UGV [34] suggested it is possible to overcome steps larger than the height of the UGV's tracked system. However, it is crucial to apply pitch angle restrictions in track system joints; there are also geometrical obstacle clearance limits for platform dimensions. In the the literature on heavy tracked vehicles, the body of work on light UGVs remains limited. Analyzing the available papers reveals that the use of multi-tracked platforms should support the ability to overcome terrain obstacles. However, each study is based on different assumptions: ground and obstacle conditions and measurement methodology, the assessing criteria, the examined UGVs' masses and dimensions, and the body architecture. Therefore, direct comparison of their results is not feasible. The aim of this paper is to enable the comparison of existing design solutions and determine the actual impact of the multi-tracked structures on the obstacle overcoming ability of light UGVs. In this way, it contributes to the available research on the mobility of lightweight multi-tracked UGVs, focusing on design aspects--rooted in contemporary solutions, indicating how their mobility can be shaped through body architecture. To achieve this, simulations were conducted on various types of UGV body architecture overcoming standardized terrain obstacles. This paper is organized as follows: Section 2 presents a methodology for simulating the obstacle negotiation performance of lightweight multi-tracked UGVs. The simulation model and assumptions are described in Section 3. Section 4 includes the simulation results and discussion. Section 5 concludes the paper, summarizing the key findings and providing recommendations for future research directions.