The JPL-developed Rocker-Bogie suspension system utilizes a six-wheel drive platform without axles or springs (click to see). The system kinematically adapts to terrain geometry and can negotiate obstacles in excess of two wheel diameters in size, allowing mobility far in excess of conventional all-terrain vehicles. Additional mobility improvements are realized by configuring the vehicle to be able to turn in place - the ability to rotate about a vertical axis without any translational motion. In the past, this has been accomplished by equipping eachof the four wheels at the corners with an individual steering actuator consisting of a gear-reduced electric motor. Each wheel can rotate 90 degrees about its own vertical axis, and subsequently the vehicle can turn in place using modified Ackerman steering principles. If the center wheel pair is also actuated (at the expense of mass and complexity), "crab" motion is made possible, enabling the vehicle to travel in any direction without rotation of the body.

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This Senior Design project will begin with identification and thorough investigation of several possible methods of steering actuation. Once the preferred method is identified, detailed designs will be established, including engineering drawings suitable for hardware fabrication. Working scale models may also be produced for concept demonstration and validation. All deliverables will be combined into a stand-alone design document and presentation. Team members will have the opportunity to develop skills and experience in real-world mechanical design and optimization processes, proper ISO-compliant engineering drawing production, and other facets of mechanical engineering as applied to spacecraft design.

What we will deliver:
1. A report on steering geometry and effects of various changes
2. Models / demonstrations of what we're recommending
3. Detailed designs for new parts
4. Mass estimates
5. Engineering drawings suitable for part fabrication at JPL