Mechanical Bumpers for Robot base
So how to determine if the robot has actually hit something? After playing around with dead reckoning navigation using the encoders this was the next task to resolve. I figure you need mechanical bumpers of some sort. It needed to know if it hit a wall on the left or right corner or if it was a direct or nearly direct hit. A soft foam surface would probably be required to be glued on the bumper to prevent damage to walls.
This is a close up of the mechanism made out of a bolt and spring and the bumper out of kiln dried wood.
Here is a view of the whole robot base hitting a wall at an angle. I tipped the base upside down in one image to show the mechanisms.
Here is a view of the whole robot base hitting a wall directly (Both switches on).