Tank Steering

[AustinSchuh]

This year, 971 integrated the ground speed sensors to get our position. We couldn't measure sideways sliding, though one more sensor and vex omni wheel would have dealt with that. Our programmer then wrote a PD loop to get the robot to follow a spline.

One of the most important lessons he learned during this process is that it helps a lot to have plots on your computer showing what you wanted, and what the bot did. He used the dashboard port, a piece of ruby code, and Gnuplot to get the data back and display it.

An easy way to go to a position on the field is to write a PD loop that controls the steering to get the angle right, and apply forwards power to get to the point. If you care if you stop there, you'll then need some sort of control for the throttle as well. A simple way to follow a path is to string these points together and move on to the next one when you get close to the first one. This all assumes you have encoders and/or gyros to measure where you are.