For my Honours project, I have chosen to design the suspension and wheels for a remote operated lunar rover. This project is inspired by the Joint Australian Space Agency and NASA lunar rover mission as part of the “Moon to Mars” initiative. The rover is intended to provide a robust, reliable and versatile technology testing platform to operate on the lunar surface, this is intended to test new technologies that will be vital for future lunar missions and potentially later missions to Mars.
A majority of semester 1 has been spent on the preliminary rover designs heavily influenced by previous rover missions to Mars, combining this with the terrain of the lunar surface I settled on a rocker-bogie suspension style. Rocker Bogie suspension is highly proven to be the style of choice for every NASA rover mission, chosen for its simple, robust design, excellent performance and passive operation. Rocker Bogie suspension incorporates a differential mechanism to facilitate motion across the rover. With ease of packaging, reliability and motion profiles in mind chose to use a differential bar mechanism mounted on top of the rover chassis. Positioning it on top of the chassis provides minimal impact on any other systems that could be required for rover operation from subsequent research projects.
I have decided to take a novel approach to the linkage design for the rover in an effort to improve reliability and durability of the component. Typocally links with rodends are used to connect the differential across the body of the rover, these rodends are shrounded to reduce ingress of martian dust and prevent damage. On the lunar surface the regolith is considerably more abrasive and much more fine, increasing the chances of dust ingress and fouling to the rodends. My solution is using a compliant link that would be designed to have lateral flexibility to accomodate the link misalignment and removing the need for rodends at either end of the link. Preliminary designs for the link show that a functional combination of buckling resistance and flexibility.
Ansys Compliant Link Simulations:
So far the promising progress has resulted in the decision to continue with the compliant link development and begin detailed design for manufacture.