I happen to write software for drivetrain systems for a living .......
One thing you need to be aware of when it comes to "Open Differentials" is that torque is applied to the wheel with the least traction.
- So -
If you were to build a drivetrain that utilizes an "Open Differential", and if you were to lift one of the wheels off of the carpet, the wheel off of the carpet would receive all of the torque and it would spin. The other wheel (on the carpet) would receive no torque and would not move.
Automotive manufacturers get arround this by using the braking system to detect the slip. The braking system will then apply brakes to the side that is spinning (off of the ground). Torque then gets transfered through the differential to the other side (on the ground).
Just be aware that if something were to pick up one side of your robot, you will effectively be stranded unless of course you have a means to brake the wheel that is off of the ground.
