2D Motion Profile Generation

[nardavin]

Hello! I have recently been looking into motion profiling to improve our capabilities for 2017 and beyond. I believe that I understand 1D motion profiling pretty well, from generating the trajectory to following it. However, I am having a hard time understanding how to control the robot along a pre-defined spline (thinking 254 auton in 2014, linked below). I think I understand the basics from 254's 2015 Champs Presentation (linked below), but I am confused how to take the overall path/trajectory and use it to generate the individual trajectories for the two sides of the drive train. Any suggestions/resources would be greatly appreciated. Thanks!

254 2014 Auton (https://youtu.be/J9K9KIYQAQg?t=14s)
Motion Profiling Presentation (https://www.youtube.com/watch?v=8319J1BEHwM)

EDIT: Typo

[Chris86]

You have a couple options, and I'm sure somebody from 254 will stop by shortly to explain their method, but here's what I like to do:

Draw a perpendicular line segment to each point on your original trajectory. The center of the segment should lay on the trajectory and its length should be the width of your robot.

Alternatively, don't generate separate left/right tracks and instead include heading as a part of your trajectory plan. Have your feedback loop include that heading to modify the left/right control efforts

Edit to provide some resources:
https://www.chiefdelphi.com/forums/showthread.php?t=126639 (A discussion of effectively how to create those paths)
https://www.chiefdelphi.com/forums/showthread.php?t=130769 (Some planners that inherently create individual left/right paths)