Analysis of Phase Shifts for a Rimless Wheel Rover
Analysis of Phase Shifts for a Rimless Wheel Rover
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无缘车轮漫游车的相移分析
DOI：
10.1109/aero50100.2021.9438348
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发表时间：
2021
期刊：
影响因子：
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通讯作者：
Juliane Skibbe
中科院分区：
文献类型：
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作者：
Juliane Skibbe
原地探索火星和月球的太空任务引起了人们的高度兴趣，但陡峭的斜坡、松软的土壤、松散的石头或高障碍物等危险地形对普通轮子的探测车来说是一个障碍。结果表明，无缘轮漫游车在这些环境中可以提高性能，同时保持漫游车的复杂性不变。与普通轮式漫游车相比，它们可以跨越更高的障碍物，被卡住的可能性显着降低，并且移动速度更快。德国航空航天中心 (DLR) 系统动力学与控制研究所设计了一种具有柔性元件的模块化无缘轮漫游车，用于在上述地形中进行行星探索。由于无框车轮，车轮周长不均匀。因此，为了提高整个流动站运动的可控性，控制每个轮子的角位置，特别是控制它们相对于彼此的角位置是合理的。在本文中，介绍并比较了其中的几种相移。选择流动站直线向前行驶的设置来比较不同车轮配置的行为和性能。针对不同的流动站速度和不同的相移，在模拟中测量了每个流动站部分的滚动角以及垂直运动。对不同相移方案在波纹度方面进行了比较。相位偏移必须通过控制器进行调整，以使干扰不会产生显着干扰。因此，采用了 PI 控制器。本文提出的研究表明，如何通过精心调整的车轮位置控制器和正确选择相移配置来提高具有柔顺辐条的无缘轮漫游车的运动性能。
Space missions to explore Mars and Moon in situ are of high interest, but hazard terrain with steep slopes, soft soil, loose stones or high obstacles are a barrier for exploration rovers with common wheels. It was shown that rimless wheel rovers yield an enhanced performance in those environments while letting the complexity of the rover unchanged. They can cross higher obstacles, have a significant lower likelihood to get stuck and can move faster compared to common wheel rovers. At the Institute of System Dynamics and Control at the German Aerospace Center (DLR), a modular rimless wheel rover with flexible elements was designed for the purpose of planetary exploration in the above mentioned terrain. Due to the rimless wheels, the wheel circumference is not uniform. Hence, for an improved controllability of the full rover locomotion, it is reasonable to have control over the angular position of each wheel and especially over their angular position relative to each other. In this paper, several of these phase shifts are presented and compared. A setup in which the rover is driving straight forward is chosen to compare the behavior and performance of the different wheel configurations. The roll angle as well as the vertical movement of each rover segment are measured in simulation for different rover speeds and different phase shifts. A comparison between the different phase shift schemes in the sense of their waviness is made. The phase offsets have to be adjusted by means of a controller such that disturbances do not interfere significantly. For that reason, a PI controller was implemented. The study presented in this paper shows how the locomotion performance of a rimless wheel rover with compliant spokes can be improved by a well-tuned wheel position controller and the right choice of the phase shift configuration.