High‐speed mobility on planetary surfaces: A technical review

Abstract

Despite the success so far accomplished in the robotic exploration of the Moon and Mars, the constraints associated with newly proposed mission concepts manifest the need for a faster surface prospection. Increasing driving velocities is being considered as a potential solution to the requirements introduced by these missions. This review presents the benefits and foreseeable challenges of using faster locomotive solutions for space exploration. Information is provided regarding the set of missions that would benefit most from faster locomotive capabilities. Starting by understanding the theoretical framework governing the interaction of wheeled robots operating over loose, sandy terrains, we delve into the foundation of Bekker's classic terramechanic equations—the most frequently used method to predict mobile robots off‐road performance. We highlight its limitations and review the efforts that have been made to expand the range of application of these theories to dynamic wheel–soil interactions. We analyze the existing experimental evidence on the effects of increasing traveling velocities under earthbound, off‐road conditions. By paying special attention to previous experiences on the lunar surface, we outline the challenges that the combination of irregular terrains and a reduced‐gravity field may pose to a fast‐moving exploration rover. The principles, mathematical models, experimental evidence, and experiences presented in this review are meant to aid in the identification of poorly understood and insufficiently studied aspects regarding high‐speed extraterrestrial surface mobility.

Traversing Steep and Granular Martian Analog Slopes With a Dynamic Quadrupedal Robot

“…Evaluating the performance of foot designs on soil is a daunting task due to the complexity of the physical effects at play. In the past, several semi-empirical wheel-soil interaction models have been developed, such as the famous Bekker model and its derivatives [Bekker, 1956, Bekker, 1960, Rodriguez-Martinez et al, 2019. While those methods have been applied to planetary exploration systems with certain success, the modeling of leg-foot-soil interaction, in comparison, is more diverse and dynamic and has only become a subject of study recently [Ding et al, 2013].…”

“…The traction coefficient µ t was determined by taking the distance l 1 (from the foot attachment to spring attachment) and l 2 (from foot attachment to contact point) into account (Equation 11). We chose the foot's bottom plate as a contact point, similar to the performance evaluation of wheel-soil interaction [Rodriguez-Martinez et al, 2019]. On the bedrock's hard surface, we used the distance from the foot mounting to the studs' tip.…”

Locomotion Strategies for Amphibious Robots-A Review

“…Wheeled robots are the most common conventional mechanism for locomotion over flat and smooth terrains or structured environments. Wheeled robots have high mobility over these surfaces as compared to other mobile robots [54]. A wheeled robot structure has a set of wheels connected to the main body by linkages and joints.…”

Traversing Steep and Granular Martian Analog Slopes With a Dynamic Quadrupedal Robot

“…Evaluating the performance of foot designs on soil is a daunting task due to the complexity of the physical effects at play. In the past, several semi-empirical wheel-soil interaction models have been developed, such as the famous Bekker model and its derivatives [Bekker, 1956, Bekker, 1960, Rodriguez-Martinez et al, 2019. While those methods have been applied to planetary exploration systems with certain success, the modeling of leg-foot-soil interaction, in comparison, is more diverse and dynamic and has only become a subject of study recently [Ding et al, 2013].…”

“…The traction coefficient µ t was determined by taking the distance l 1 (from the foot attachment to spring attachment) and l 2 (from foot attachment to contact point) into account (Equation 11). We chose the foot's bottom plate as a contact point, similar to the performance evaluation of wheel-soil interaction [Rodriguez-Martinez et al, 2019].…”