Concepts for Tunable Springs in Robots

Abstract

The wheg-driven robots are kind of robots that use rimless wheels to have the advantages of both wheels “fast constant speed” and legs “ability to overcome obstacle with non-uniform shapes”. The wheg-driven robots are useful in many fields such as security, exploration, surveillance… etc.. The whegs robots have the disadvantage of the vertical alternation of the robot’s body in the direction perpendicular to the direction of motion due to rimless wheel. Based on the mechatronics design methodology, a new approach for a wheg-module driven robot is introduced. The wheg module with electromagnetic spokes is a wheg appendage with actively controlled spokes, to enhance the wheg performance by decreasing the vibration of the robot during motion over smooth terrains (alternation in the direction perpendicular to the direction of motion), increasing its ability to overcome obstacles without the need to change the design. The wheg was studied using mathematical model. Simulations using the multi-body simulation tool ADAMS View® were done to help improving the concept. Based on the results from the mathematical model and simulations, a prototype for the wheg module with electromagnetic spokes was manufactured, and experiments were done to evaluate the concept. Through the thesis a complete mathematical model for the wheg-module kinematics is introduced to help in the future studies for making the robot applicable to be used as a transportation tool. The simulations show the effect of the different parameters on the vertical alternation of a single wheg-module and a half robot model. Keywords: Whegs, bio-inspired robotics, locomotion, rimless wheels, leg-wheel robot, tunable springs in robots