I am in the concept phase of a driving robot. The two wheels on the front axle will be powered, while the rear will be dragged along. The rear is also responsible for steering but this has noting to do with my question.
Since the robot is required to make relatively sharp turns at high speed. Therefore I have two options to compensate the different speeds on both sides. On the one hand, a differential gear in the front axle could be used. It would be powered by one motor then. On the other hand, I could simply use two motors directly powering each a front wheel. This way I could simulate the differentiation in software.
I'd like to go for the first approach, using the hardware differential. But I have the one concern with it. Would a robot vehicle with differential gear still move straight, without explicit steering applied?
My imagination is that, with those wheels not being solidly connected, the robot would move in random curves which I'd have to compensate with a lot of steering then. I know that for real cars, differential gears are standard and do their work, but now I am talking about a small robot measuring about 6 inches.