Has 6 wheeled designs surpased tank treads

[Paul Copioli]

ShadowKnight,

The force being distributed along the tread has absolutely nothing to do with the ability to push, unless... the surface that your treads contact fails due to the contact. If the wheel design is wide enough such that the force imparted on the carpet does not make the carpet fail (i.e. tear apart like in 2002), then it will provide the exact same pushing force as a tread made of the same material provided the robot is the same weight.

Mike Norton's post is very accurate, but notice that the advantages of the tread design (disadvantages, too) really are not related to pushing force. Regarding Mike's point #3, I guarantee that if his team put a six wheel design with the same tread material they would still be in the top 5% of pushing robots.

Now, specifically regarding 2002: treads had a much better chance of not tearing the carpet than wheeled designs because they distributed the load. Tearing the carpet leads to less traction. The carpet of 2002 related to the possible weight of a fully loaded robot (around 500+ lbs) was like sand to a construction vehicle. Treads helped dissipate the pressure on the carpet to a point where the carpet would no longer fail. Wider wheels would provide similar functionality.

-Paul