The Corner Case Problem

How we solved the corner case problem!

What is the corner case problem?

When the robot is near one of the four corners on the field and depending on how far off the robot's heading is to one of the four 'half cardinal' angles (45°, 135°, 225°, 315°). In this case, all three sensors will be simultaneously calculating incorrect vector components. This would result in the final pose estimate to be off by about 30-50 inches.

We finally derived a way to calculate the pose estimate with high accuracy. When all three sensors are in use, a special safety condition gets executed. Depending on which half cardinal angle the robot is closest to, the left and right sensors will add their appropriate components to either the x-list or y-list.

For the front sensor however, it will not be calculating anything. Previously it would add its matching vertical component to y-list or its matching horizontal component to x-list. However this is just redundant, as the same calculations are already included from the left/right sensors.

And finally by averaging these two lists we can derive the true robot position with great accuracy!