This paper introduces an omnidirectional all-terrain robot, made of a fusion between screw-drive and mecanum wheels. The vehicle is designed to operate on flat surfaces as well as on various uneven soft ground such as mud or snow. The project inspirations have been fed with many existing vehicles that focus on one or the other mechanism and that knowledge has been used to address specific design challenges. Yet, upon reviewing the field, it appears that the proposed design is unique and is not patented. The research phase consists of several prototype proposals with the aim of maximizing efficiency and easy of construction. This paper discusses the different prototypes with respect to tests and results but also suggests future improvements to the design.
This project consists of the implementation of a vehicle with a screw-drive and mecanum wheel fusion. The aim that the robot should be capable of operating on flat and planar surfaces, with mecanum wheels allowing the robot to move easily in all directions. Whilst, the screw propelled vehicle mechanism is useful to deal with harsh terrain in extreme environments (i.e. recovering cosmonauts in Russia, ground surveying…). This section gives a brief chronology of both mechanisms and introduces few research papers that served as the starting point for the project.
Other Sections: Design and Implementation, Experiments, Discussions
This paper has introduced the concept of a mecanum wheel screw propelled robot which with its novel propulsion method would be capable of omnidirectional movement on flat ground and soft variable terrain. Throughout the course of the project different designs ideas have been continuously discussed within the team and updated to the overall model design which culminated in prototype for the Mark 6 Screw design and Mark 4 robot model which, due to unforeseen circumstances of COVID-19 could not be completed to the satisfaction of the group prior to submission. Computer-aided design and Computer Aided Manufacturing have been used to design and manufacture the project and lesson learned throughout have been fed back in to improve the design. Finite Element Analysis and Material Analysis have been conducted to assess options for possible future large scale prototypes to be manufactured with high safety factors. The discussion reviews the areas which could have been improved with more availability of manufacturing facilities and general component market. Overall the project has been considerably successful to have a working tethered prototype which has been tested in the two mediums required to least basically test the project whilst under pressure from an unprecedented circumstance of being effectively unable to rebuild prototypes. In the future, this prototype could provide a novel alternative to current propulsion methods for an all-terrain vehicles and robots.
We would like to express our gratitude to Dr. Swen Gaudl, the module’s leader, for his advice and his support throughout the project. Also, special thanks to Jake Shaw-Sutton, the robotics senior technician of the University of Plymouth, for providing us all the components we needed as well as his help on the Fusion 360 software comprehension. Special thanks to Joel Pallent for printing the Mark 4 Screws during such trying times, to Christine Bulman for proofreading the report, and to Stephanie Fortune for turning Harrys simple drawings into vibrant life for the Mark 6 Screw drawings.
Final Version design: https://www.youtube.com/watch?v=LLqzmmXOui0
Stress Test 1: https://www.youtube.com/watch?v=ebu12kIJMIo
Stress Test 2: https://www.youtube.com/watch?v=KxWnDmyO0Xo&feature=youtu.be
