Sweep Scanning LiDAR

[Mechvet]

Originally Posted by baumgartensam

This year we have a XV11 lidar unit on our robot.

One of the largest issues with doing any sort of localization on the FRC field is the polycarb walls. At least in our experience, it is completely invisible to most LIDAR units. Unfortunately polycarb is very transparent to waves in the visible spectrum. Our unit was in the high 700um range which put it out of the visible spectrum, but still low enough to go right through the polycarb. We didn't observe many issues with the diamond plating as long as we did some simple filtering to get rid of rediculous values. The tower works well as a defining feature making common localization algorithms such as AMCL work quite well.

Unfortunetally, we ran into some issues with the housings holding our LIDAR units interfering with the rough terrain so we had to move them to new places which don't have as broad of a viewing angle making localization difficult.

We are however still using one of the units to identify and align with boulders on the field which helps when there isn't a clear line of sight with a ball we are trying to grab. The LIDAR data is much more useful for identifying balls and transforming the balls location into a usable coordinate frame than cameras and CV.

Appreciate the feedback on these units. If this season's test cases go well, we'll be looking into getting a unit or two for the students to start learning a bit of localization with more real-world tools.