[论文解读] The effects of increasing velocity on the tractive performance of planetary rovers

David Rodríguez‐Martínez, Fabian Buse+2 more|arXiv (Cornell University)|Jun 3, 2023

Agriculture and Farm Safety被引用 5

一句话总结

本研究通过在橄榄石砂和碳酸钙基粉质土壤上进行单轮试验，实验探究了提高速度对行星漫游车牵引性能的影响。结果表明，当速度超过0.2 m/s后，牵引力和牵引效率显著下降，同时轮子下陷深度随速度增加而增大；在1 m/s时，柔性轮相比刚性轮表现更优，牵引力提高一倍，下陷深度降低18%（在低滑移条件下）。

ABSTRACT

An emerging paradigm is being embraced in the conceptualization of future planetary exploration missions. Ambitious objectives and increasingly demanding mission constraints stress the importance associated with faster surface mobility. Driving speeds approaching or surpassing 1 m/s have been rarely used and their effect on performance is today unclear. This study presents experimental evidence and preliminary observations on the impact that increasing velocity has on the tractive performance of planetary rovers. Single-wheel driving tests were conducted using two different metallic, grousered wheels-one rigid and one flexible-over two different soils, olivine sand and CaCO3-based silty soil. Experiments were conducted at speeds between 0.01-1 m/s throughout an ample range of slip ratios (5-90%). Three performance metrics were evaluated: drawbar pull coefficient, wheel sinkage, and tractive efficiency. Results showed similar data trends among all the cases investigated. Drawbar pull and tractive efficiency considerably decreased for speeds beyond 0.2 m/s. Wheel sinkage, unlike what published evidence suggested, increased with increasing velocities. The flexible wheel performed the best at 1m/s, exhibiting 2 times higher drawbar pull and efficiency with 18% lower sinkage under low slip conditions. Although similar data trends were obtained, a different wheel-soil interactive behavior was observed when driving over the different soils. Overall, despite the performance reduction experienced at higher velocities, a speed in the range of 0.2-0.3 m/s would enable 5-10 times faster traverses, compared to current rovers driving capability, while only diminishing drawbar pull and efficiency by 7%. The measurements collected and the analysis presented here lay the groundwork for initial stages in the development of new locomotion subsystems for planetary surface exploration. At the same time...

研究动机与目标

• 探究行驶速度增加对行星漫游车牵引性能指标的影响。
• 评估速度对不同土壤类型下牵引力、牵引效率和轮子下陷深度的影响。
• 比较刚性与柔性齿纹轮在不同速度和滑移比下的性能表现。
• 识别在高速移动与牵引损失之间实现平衡的最优速度范围，以支持未来高速行星漫游车的设计。
• 为开发基于速度的牵引力模型提供实证数据，用于漫游车运动系统。

提出的方法

• 利用机械臂精确控制滑移比和轮速，开展单轮驱动试验。
• 在两种土壤类型（橄榄石砂，RMCS14；碳酸钙基粉质土壤，RMCS13）上使用两种金属齿纹轮（刚性与柔性）进行测试。
• 在0.01至1 m/s的速度范围和5%至90%的滑移比范围内测量牵引性能。
• 评估三项关键指标：牵引力系数、轮子下陷深度和牵引效率。
• 在受控环境条件下进行实验，以隔离速度对其他变量的影响。
• 拍摄高速视频，分析高速下土壤行为及轮-土相互作用动力学。

实验结果

研究问题

• RQ1 提高行驶速度如何影响行星漫游车车轮的牵引力系数？
• RQ2 在不同行星土壤类型中，速度与牵引效率之间存在何种关系？
• RQ3 轮子下陷深度如何随速度变化？这是否与先前假设相矛盾？
• RQ4 在松散土壤上，刚性与柔性轮设计在高速（如1 m/s）下的性能表现有何差异？
• RQ5 在高速条件下，橄榄石砂与碳酸钙基土壤的土壤行为有何不同？

主要发现

• 当速度超过0.2 m/s后，牵引力和牵引效率均显著下降，尤其在0.4 m/s以上时下降最为明显。
• 轮子下陷深度随速度增加而增大，这与先前认为高速可因动力效应减少下陷的假设相悖。
• 在1 m/s时，柔性轮在低滑移条件下牵引力达到刚性轮的两倍，且下陷深度低18%。
• 当速度超过0.4 m/s时，橄榄石砂（RMCS14）表现出类似流体的行为，而碳酸钙基土壤（RMCS13）则在车轮上出现更多土壤堆积。
• 尽管高速下性能有所下降，但0.2–0.3 m/s的速度范围可实现5–10倍的更快行驶，仅导致牵引力和效率降低7%。
• 土壤类型显著影响轮-土相互作用，高速条件下表现出明显不同的宏观行为——橄榄石砂呈现流体特性，而碳酸钙基土壤则出现土壤堆积现象。