Team Members:

Aditi Daniel, Aliza Mehdi, Diya Rajon, Shveta Sundar

Background:

Although wheeled mechanisms excel on flat, rigid ground, they are not well suited for soft terrain like sand or soil. Continuous ground contact on such surfaces leads to increased energy losses from multiple sources.

Compaction Work: all of the energy goes into deforming the surface instead of propelling the wheel forward
Sinkage: the high pressure causes the wheel to sink and the energy goes into the wheel trying to climb out of the hole
Sidewall Drag: sand is pushed to the side causing an increase in horizontal resistance, which effectively causes the need for more force to keep things moving continuously

On the other hand, legged mechanisms such as the Jansen leg maintain intermittent contact with the ground, i.e., only touching the ground when necessary. More specifically, a Jansen leg operates in two phases.

Stance Phase: the foot of the leg pushes back on the ground causing forward motion (thrust)
Swing Phase: the leg is in the air while repositioning for the next step

The intermittent contact of the mechanism with the ground decreases the effective horizontal resistance by restricting ground interaction during the stance phase, reducing sinkage effects due to a larger surface area, and preventing any sliding motion by the swing phase of the mechanism.

The Jansen leg mechanism specifically has the ability to be driven by a continuous rotational input which can be manipulated via motor-driven actuation.

Problem Statement

The goal of this project is to build a kinematic demonstration of a Jansen leg walking mechanism that can operate at different speeds. Instead of using wheels, the mechanism is driven by a continuous rotational input. A mechanical transmission system with different gear ratios is used to change the input speed, allowing us to observe how the Jansen leg motion and walking behavior changes with speed.

Jansen Leg Mechanism + Manual Transmission

Video Demonstration of Project

07 - Dual-Speed Strandbeest Mechanism

Team Members:

Background:

Problem Statement

Table of Contents:

https://cloud.wikis.utexas.edu/wiki/spaces/RMD/pages/510034097