In 2004 we happened upon a simple, robust, and fast method for climbing the stair. We put drop down ramps made of UHMW plastic on the front of the robot and had 4 large knobby pneumatic tires. The ramps would start the match folded up and would drop down and latch into place, giving the front face of the robot a sloped leading edge that would be just above the top of the step, sort of like an amphibious car.
To climb the stair the driver would simple turn the robot to face the stair and apply throttle. The ramps would lift the nose and when the front tire hit the stair’s edge it would climb onto it. Because the robot would high center between the wheels, we put UHMW plastic strips on the frame so we could glide across until the rear wheels would engage. To get down from the platform we would just drive off and bounce a bit. It was not a finesse move and required the robot to tip about 30-45 degrees, so you needed a relatively low CG. I don’t think we ever tried, but I think we could have climbed multiple stairs if there was a good edge to bite into like in 2004.
This method served us very well and was very KISS, perhaps the KISSiest
Jay