[Dprglist] self driving trucks and the desert

[David P. Anderson]

Hi Paul,

I've been reflecting on your comments Tuesday evening about the self 
driving trucks needing lots of waypoints to stay on the road, vs. the 
robot demos shown that evening using more sparse waypoints.

In particular the observation that the robots are operating essentially 
unconstrained, as in a desert, except for the need to avoid obstacles, 
while the trucks need to stay centered on the roadway.

I'm not sure that is correct.  It seems that the long hallways that my 
robot had to navigate is the functional equivalent of the trucks' 
roads.  So the robot is not in fact operating as in a desert, 
unconstrained.  But must instead follow a fairly narrow and constrained 
path.

Now if that is the case, why does it not use hundreds waypoints to 
accomplish that task?  Or more to the point, why the army trucks do?

So I pondered this for a while and it occurred to me that in the robots' 
case, the waypoint navigation is not responsible for keeping the vehicle 
on the "road," i.e., centered in the hallway.   Rather that is the task 
of a separate group of sensors and behaviors.   But for the convoy, the 
navigation behavior is responsible for navigation in the global sense as 
Chris was describing, and also in the local sense of staying centered on 
the road.

Now for the army trucks to do it the way the robots do would also 
require a second suite of sensors and behaviors to stay on the road --- 
not trivial --- while the method you describe can all be done with just 
GPS, no other sensors required.   (Though I assumed or maybe you told me 
there are forward looking radar to keep from running into the truck in 
front of you.)

In any case, the desert vs. constrained roadway is perhaps not the best 
analogy for what the robots are doing.

cheers!

David