Lunar Rover Wheels Design & Analysis

Abstract

Lunar rover are robotic vehicles that travel on extra-terrestrial surfaces doing heavy scientific duties and experiments. The surface of the moon contains fine soil that consists of dust, rough rock, and crust that makes the wheels designed for such missions non-similar to what wheels on earth's surface are, especially with the chance of the vehicle entrapment into the soil and traction control failure. In Mohammed Bin Rashid Space Centre (MBRSC), the first lunar mission (i.e. Rashid-1 Rover) has been executed and is ready for launch in as early as 2023. In this report, the wheels of Rashid-1 rover are investigated, in addition, the effect of changing the wheel parameters and grousers on the behaviour of the vehicle in terms of drawbar pull, the torque needed, and the tractive efficiency is done using terramechanics. Thereafter, finite element analysis of the wheel-soil interaction on the current wheel design is done to check the stress concentrations on the wheel. Both models analytically and numerically compared, which prove to showcase the validity of the numerical model, as well as successfully attaining that Rashid-1 wheels are able to withstand movement on the lunar surface without geometrical failures. Results using both models show that the wheel has a maximum tractive efficiency at 10-15% slip, increasing the diameter, width, and height of grousers increase the required drawbar pull and torque, while reducing sinkage except for the case of increasing the height of grousers. However, increasing the diameter reduces the stress on the grousers, while increasing the stress on the ribs. Moreover, increasing the number of grousers results in better performance until a steady value, however, it increases the stress on the grousers while reducing the stress on the ribs. Finally, increasing the height of grousers benefits the magnitude of stress on the grousers up to a limiting value, whereas it does not affect the stress values on the ribs.

Date of Award	May 2022
Original language	American English