Traveling performance evaluation of planetary rovers on loose soil

Abstract

In designing a planetary rover, it is important to consider and evaluate the influence of parameters such as the weight and dimensions of the rover on its traveling performance. In this study, the influence of a rover's weight on its performance was evaluated by conduct experiments using a monotrack rover and an inline four‐wheeled rover with different rover weights. Then the influence of the wheel diameter and width was quantitatively determined by performing experiments using a two‐wheeled rover, equipped with wheels, with different diameters and widths. The results of the experiments were compared with those of a numerical simulation based on terramechanics. Finally, the influence of the wheel surface pattern on the traveling performance of planetary rovers was evaluated by conducting experiments using a two‐wheeled rover equipped with wheels with different numbers of lugs (i.e., grousers) on their surfaces. Based on the results of these experiments, we confirmed the following influences of the parameters: in the case of the track mechanism, the traveling performance does not change with the increase in rover weight. On the other hand, in the case of the wheel mechanism, an increase in rover weight decreases the traveling performance. Moreover, the experimental results show that the wheel diameter contributes more to the high traveling performance than the wheel width. In addition, a comparison between the experimental and simulation results shows that it is currently difficult to accurately predict the traveling performance of lightweight vehicles on the basis of terramechanics models. Finally, the experimental results show that having lugs always improves the traveling performance, even at the expense of wheel diameter. © 2012 Wiley Periodicals, Inc.

Path planning for reconfigurable rovers in planetary exploration

“…Matlab is used to create the Cost Map as well as the square grids in charge of visualization and dynamic interaction with the rover. Furthermore, since there is no much research about wheel-soil interaction for the wheel-walking mode comparing to normal drive [7], a function is built from several simulations performed in [4] to decide which locomotion mode is better for a certain terrain depending on wheel-soil interaction parameters. This function is used by the path planner in its cost function and works as follows: it returns the value of the power required to traverse a certain terrain depending on its soil parameters and the locomotion mode employed.…”

Modified model for shear stress distribution using TRI-1 Lunar soil simulant

“…Many research works are carried out on study of grousers on motion performance (Liu et al, 2008), study of motion dynamics and control of planetary rovers (Yoshida et al, 2001), study on stability control of a wheel-lugged rover (Grand et al, 2002), terrain parameter estimation for planetary rovers (Iagnemma et al, 2004) and study on motion performance of a rover which is evaluated by its drawbar pull, driving torque which is related to normal stress and shear stress distribution produced by the wheel at the wheel-soil interface (Wong, 2001;Sutoh et al, 2010). Hence, determination of normal stresses and shear stresses plays a major role in the wheel-soil interaction.…”

A grouser spacing equation for determining appropriate geometry of planetary rover wheels

“…Recently, Sutoh et al [7] demonstrated that there is a limit to the gains attainable from increasing the number of grousers. They also showed that traction gains from grousers are greater than those provided by a wheel with simply a larger effective diameter, as some past literature had suggested would be the case.…”