[desi_technology]

We did crab drive last year. It worked well after we fine tuned the steering algorithm. The setup we used four cim motors that were vertically mounted on drive modules, which had the custom gearing in them. The robot moved about 9.6 FT/sec. We turned these modules by having two steering modules, one in front and one in back. The modules were powered by window motors, so the front and back drive modules were independently linked, not like traditional crab drive. It was controlled by close loop control using a derivative, which slowed the turning the wheels away from center and speeds up when returning to center, so you maintain accuracy. There where two pots on the steering modules which would turn the wheels in opposite directions so it could turn. If you have any questions about team 176's crab drive just ask?