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Servo Magazine (January 2006)
Appetizer - Dan Kara
Ask Mr.Roboto - Pete Miles
GeerHead - David Geer
Intermediate Robots - Dave Shinsel
Mind / Iron - Dave Prochnow
Robotics Resources - Gordon McComb
Robytes - Jeff Eckert
Stepping Motor Basics - Richard Panosh
Then and Now - Tom Carroll
Twin Tweaks - Evan & Bryce Woolley
Projects:
Build Your Own Planetary Rover Bogey Suspension Platform - Alan Federman
KIT Kollege - part 6 - Dave Prochnow
Power-Assisted Cart - Thomas H. Smith
Progammable Logic - Part 1 - Gerard Fonte
Build Your Own Planetary Rover Bogey Suspension Platform
by Alan Federman
Just think about it. Suppose you had a four wheel vehicle with no suspension. If one wheel hit a rock or a curb and tried to climb it, you’d soon have two wheels up in the air, and only 50% of your traction. If your suspension could automatically adjust to the terrain, you’d always have at least three wheels on the ground and 75% or more of your traction. A rule of thumb is a round wheel can’t climb a curb generally greater than 1/3 of its diameter. A four wheel system with a bogey suspension can usually get by at a 1/2 to 2/3. Add a rocker to the bogey, and you can usually climb an obstacle 1 to 1.5 diameters. Another advantage of a bogey suspension is the platform tends to stay level with the ground. So a flush mounted camera is always aligned with the local horizon.
There are several ways to make a bogey. NASA’s rovers use differential gears. You could also use simple tie rods, like the control rods used by RC modelers. For my bogey, I chose pneumatic cylinders, because I could get away with being a sloppy machinist, and I happened to have a couple of extra ones lying about. New cylinders are kind-of expensive, but used ones aren’t. If you were really strapped, you probably could make your own by using a pair of screen door closers or bicycle pumps.
Colums / Departments:
Mind / Iron
Ask Mr. Roboto
GeerHead
Rubberbands
Events Calendar
Robytes
Lessons From The Lab
Tetsujin Info
New Products
Robotics Showcase
Robotics Resources
Menagerie
Twin Tweaks
Then and Now
Appetizer
Tetsujin Tech
The Assembly Line
SERVO web site
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