Difference between revisions of "Omni Directional Wheels"
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==Description of Project== | ==Description of Project== | ||
The final product is a “robot” that moves omni-directionally.I used holonomic wheels and continuous rotation servo motors for locomotion, and a Playstation 2 thumbstick for control. | The final product is a “robot” that moves omni-directionally.I used holonomic wheels and continuous rotation servo motors for locomotion, and a Playstation 2 thumbstick for control. | ||
| + | ==Motavation== | ||
| + | ===Segway's new RMP=== | ||
| + | These mecanum wheels use rollers on a 45° angle around the circumference to allow lateral motion. I saw this online and I though that it looked cool, and possible for a project (If I could get the wheels.) As it turned out I could not get the mecanum wheels but it did start me thinking about methods for omni-directional motion. | ||
| + | ====Mecanum Wheels==== | ||
| + | When all the wheels spin forwards, the lateral forces created by the angle of the rollers cancel and the device moves forward normally. When the wheels spin in different directions, the forwards and backwards forces cancel and the device moves laterally, diagonally or spins. | ||
| + | |||
==Design== | ==Design== | ||
[[Image:GoffFinal.JPG|thumb|300px|right]] | [[Image:GoffFinal.JPG|thumb|300px|right]] | ||
| − | My design consists of two sets of wheels perpendicular to each other driven by servo motors. For control I took a Playstation 2 | + | My design consists of two sets of wheels perpendicular to each other driven by servo motors. For control I took a Playstation 2 controller apart and used the thumbstick in stead of the two potentiometers in the "pot boxes" we used to control the arm. The script is very simple. It scales the potentiometer values from the thumbstick to add to the pulse widths for the motors |
===Holonomic Wheels=== | ===Holonomic Wheels=== | ||
| − | Holonomic wheels (also known as [http://en.wikipedia.org/wiki/Omni_wheel omni wheels])have rollers perpendicular to the direction of rotation. This allows them to roll normally and slide laterally. | + | Holonomic wheels (also known as [http://en.wikipedia.org/wiki/Omni_wheel omni wheels])have rollers perpendicular to the direction of rotation. This allows them to roll normally and slide laterally. By positioning them so they are not parallel they can move omni-directionally. My design uses two sets of wheels perpendicular to each other, but any no-parallel arrangement will work. |
Revision as of 21:27, 9 December 2008
This is the page for Tad Goff's E5 final project, Omni-Directional Wheels
Contents
Concept
Build a device that moves omni-directionally using holonomic or 'omni' wheels. There will be four wheels arranged around the chassis such that there are two opposing sets. The device will be controlled by an analog thumbstick salvaged from a Playstation 2 controller, and will be programmed in MatLab.
Description of Project
The final product is a “robot” that moves omni-directionally.I used holonomic wheels and continuous rotation servo motors for locomotion, and a Playstation 2 thumbstick for control.
Motavation
Segway's new RMP
These mecanum wheels use rollers on a 45° angle around the circumference to allow lateral motion. I saw this online and I though that it looked cool, and possible for a project (If I could get the wheels.) As it turned out I could not get the mecanum wheels but it did start me thinking about methods for omni-directional motion.
Mecanum Wheels
When all the wheels spin forwards, the lateral forces created by the angle of the rollers cancel and the device moves forward normally. When the wheels spin in different directions, the forwards and backwards forces cancel and the device moves laterally, diagonally or spins.
Design
My design consists of two sets of wheels perpendicular to each other driven by servo motors. For control I took a Playstation 2 controller apart and used the thumbstick in stead of the two potentiometers in the "pot boxes" we used to control the arm. The script is very simple. It scales the potentiometer values from the thumbstick to add to the pulse widths for the motors
Holonomic Wheels
Holonomic wheels (also known as omni wheels)have rollers perpendicular to the direction of rotation. This allows them to roll normally and slide laterally. By positioning them so they are not parallel they can move omni-directionally. My design uses two sets of wheels perpendicular to each other, but any no-parallel arrangement will work.
