Finite Element Simulations of the Wheels of the Rashid Lunar Rover

Lunar Rovers are robotic vehicles that travel on extra-terrestrial surfaces performing certain scientific duties and experiments. The design and analysis of wheels for a lunar rover are significantly different than what is considered for applications on Earth. The main reason has to do with the lunar environment and its' surface, which is covered by a deep layer of fine regolith. Therefore, researchers have followed different design methodologies to obtain optimum wheel designs that suit the lunar environment, especially with the chance of the vehicle entrapment into the soil and traction control failure. Mohammed Bin Rashid Space Centre (MBRSC) has been developing the Rashid lunar rover, the first of its kind to be developed in the United Arab Emirates, which is expected to be deployed on the surface of the moon in as early as 2023. In this study, the finite element method is used to study the effect of the different wheel and grousers geometrical parameters on the wheel performance while traveling on the lunar surface. In addition, the points of stress concentration are investigated under various geometrical configurations for the wheel design. The obtained results show that the wheel is expected to perform well according to the mission objectives at the specified velocity and the intended slip ratio, where increasing the wheel diameter, number of grousers, and height of grousers do not enhance the performance of the required drawbar pull further in the current design. Results show that increasing the wheel diameter reduces the stress on the grousers, however it will increase the stresses on the ribs. Moreover, increasing the number of grousers results in a better performance up to a plateau value, however, it increases the stresses on the grousers while reducing the stresses on the ribs. Finally, increasing the height of grousers reduces the magnitude of stresses on the grousers up to a limiting value, whereas it does not affect the stress values on the ribs.