Team 2175 Logo Motion Robot Design

[AllenGregoryIV]

Originally Posted by Chris is me

They travel faster in that they can be geared higher than two motors would normally push in that direction; however drives like these allow the user to configure a particular direction to drive with more than the equivalent of two motors of "power", allowing a higher free speed / lower gear ratio in the primary direction of travel.

In short, "yes" but "no".

I am not sure I understand the first sentence here. A robot with four omni wheels placed 90 degrees apart will travel approximately 1.4 (or square root of 2) times faster than wheel velocity in it's orthogonal directions. At directions parallel to any wheel rotation the robot will only be able to travel at wheel velocity like any two wheeled robot. This is not saying it is geared any different. The robot is actually moving faster than any one wheel is spinning.

Your second statement is correct that by adding motors you are able to get a higher power, this is always the case. However this also makes doing the calculations for holonomic control of the robot very challenging since different wheels are able to travel at different velocities and will have different accelerations.

So to sum up yes their drive train will have more power and acceleration when traveling forward and backward than one that uses 1 CIM on each wheel (assuming consistent gearing). The drive with 1 CIM on each wheel will have a greater top speed when strafing and consistent control to all 4 wheels. These are just two different design and both have there ups and downs. And as always you can gear any drive train to have more speed when you sacrifice torque.