Further study of the method of approach to testing the performance of extraterrestrial rovers/rover wheels on earth

• Published in: Journal of terramechanics Vol. 49; no. 6; pp. 349 - 362
• Main Authors: Wong, J.Y., Kobayashi, Taizo
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.12.2012
• Subjects: Compaction resistance; Extraterrestrial rovers; Gravity effects; Mobility; Parabolic flight manoeuvres; Rover wheels; Sinkage; Slip–sinkage; Soil simulant; Testing; Rover wheels; Slip–sinkage; Mobility; Gravity effects; Compaction resistance; Soil simulant; Parabolic flight manoeuvres; Sinkage; Extraterrestrial rovers; Testing
• ISSN: 0022-4898; 1879-1204
• DOI: 10.1016/j.jterra.2012.10.004

► A new method for testing the performance of rover wheels on earth. ► New procedures for estimating rover wheel sinkage on extraterrestrial bodies. ► New procedures for estimating rover wheel resistance on extraterrestrial bodies. ► Basic features of the new method and procedures substantiated by test data. ► Gravity found to have little effect on the slip–sinkage relationship for rover wheels. The current practice for experimentally evaluating the performance of extraterrestrial rovers/rover wheels is to conduct tests on earth on a soil simulant, appropriate to the regolith on the extraterrestrial body of interest. In the tests, the normal load (force) applied by the rover/rover wheel to the soil simulant is set identical to that expected on the extraterrestrial surface, taking into account its acceleration due to gravity. It should be pointed out, however, that the soil simulant used in the tests is subject to earth gravity, while the regolith on the extraterrestrial surface is subject to a different gravity. Thus, it is uncertain whether the performance of the rover/rover wheel obtained from tests on earth represents that on the extraterrestrial surface. This issue has been explored previously. A method has been proposed for conducting tests of the rover/rover wheel on earth with identical mass to that on the extraterrestrial surface, instead of with identical normal load used in the current practice [1]. This paper provides further evidence to substantiate the merits of the proposed method, based on a detailed analysis of the test data obtained under various gravity conditions, produced in an aircraft undergoing parabolic flight manoeuvres [8]. In the study, the effect of slip on wheel sinkage has been evaluated. It is found that gravity has little effect on the slip and sinkage relationship of the rover wheel under self-propelled conditions.