College - Author 1
College of Engineering
Department - Author 1
Mechanical Engineering Department
Degree Name - Author 1
BS in Mechanical Engineering
College - Author 2
College of Engineering
Department - Author 2
Mechanical Engineering Department
Degree - Author 2
BS in Mechanical Engineering
College - Author 3
College of Engineering
Department - Author 3
Mechanical Engineering Department
Degree - Author 3
BS in Mechanical Engineering
College - Author 4
College of Engineering
Department - Author 4
Mechanical Engineering Department
Degree - Author 4
BS in Mechanical Engineering
Date
12-2019
Primary Advisor
Lee McFarland, College of Engineering, Mechanical Engineering Department
Abstract/Summary
Passive locomotion is the ability for an object to move from one place to another by the means of the environment. In nature species such as tumbleweed, fox tails, plankton, and man o’ war jellyfish rely on passive modes of transportation for survival and are able to cross vast distances with little to no expenditure of their own energy. This document seeks to explore the feasibility of building a machine relies on the energy of Mars’ environment to explore the Martian surface.
The “Tensegrity Tumbleweed Locomotion” (nicknamed Tumble Bot) senior project was sponsored by NASA Jet Propulsion Laboratory (JPL). The goal of this project was to create a proof-of-concept design that uses passive locomotion to traverse at least 20% of Mars’ surface. The structure must be capable of transporting a 1.5 kg payload of instrumentation that would be used to collect data and images of the surface. Ideally Tumble Bots would be able to be deployed in several locations all over the Martian surface so that a basic knowledge of the surface conditions over a wide area could be developed. This knowledge would then serve to guide future missions that would conduct more in-depth testing of areas of interest. Ideally the ball would be able to overcome small obstacles and be able to get out of small holes.
Extensive research, ideation, and testing was done to determine the optimal design for a structure that would meet as many of the design criteria as possible. The design criteria evolved substantially over the first two quarters of this project as the difficulty of this problem was more thoroughly understood. Folding, overcoming rocks, getting out of holes, and assembly of a fully functional prototype were all removed from the design requirements. This project was pitched as a tensegrity structure, but during the design process it was decided that tensegrity structures with curved members met the design criterion better than the traditional tensegrity structures with straight members. The members continued to be modified to make the structure more spherical. Ultimately it was decided that a non-tensegrity structure would best meet the weight requirements while still producing a spherical geometry.
The engineering challenge addressed by this project was a very large, open-ended problem. The final design presented in this report roughly outlines the optimal design, but still has room for improvement. Development of a more optimal design could continue beyond the time that was allotted to complete this project.
This Final Design Review aims to guide the reader through the development of this project and explains what analysis was done in order to draw the conclusions outlined in this report. The progression of the design process is clearly explained with the hope that it can be easily followed and built upon by future endeavors to make a successful Tumble Bot. Included in this document are suggestions of how this project could best be continued.
URL: https://digitalcommons.calpoly.edu/mesp/508