/overconstrained-locomotion

Investigating overconstrained locomotion in theory and deploying in Webots simulation

Primary LanguageCMIT LicenseMIT

overconstrained-locomotion

  • This is my Undergraduate thesis. This work investegated possible locomotion of an overconstrained leg.
  • This work has some initial results of monopod hopping with overconstrained leg; however, it is restricted to a sagittal plane. An independent robot with overconstrained leg must has at least 2 legs. Therefore, future works are expected to solve possible biped/quadruped locomotion.
  • Details of this work can be seen in docs\sustechthesis_WangBY_UG21.pdf

Bennett's four-bar linkage

This is an exapmle, or the source of our ispiration, of a Bennett's linkage.

bennett linkage

Overconstrained leg

The overconstrained leg is literally half of the four-bar linkage. The first two joints 1 and 2 are chosen to be actuation.

overconstrained leg

Controller design through templates composition

We first studied a monopod with overconstrained leg. Its frontal plane and sagittal plane view is shown below:

overconstrained leg

Controlling this monopod jumping in a sagittal plane requires consideration of its foot placement that is not directly underneath the body. $\delta$ here is the angle of projection from leg to YZ plane. The hopping controller is inspired by PennJerboa 1 and some other works 2 3 4.

Webots experiments

webots sim

Results

Here are some initial results of the monopod hopping in the sagittal plane.

phase space

phase space

phase space

sagittal plane trajectories

Some experiments are recorded in videos.

References

[1] The Penn Jerboa: A Platform for Exploring Parallel Composition of Templates

[2] Legged robot that balance

[3] Reactive Planning and Control of Planar Spring–Mass Running on Rough Terrain

[4] Analysis of a Simplified Hopping Robot