Pure Pursuit vs Stanley, Which is better?

[Farmboy94]

I’ve been using pure Pursuit on a 470 Case Steiger with a dual antenna setup(mounted towards the front edge of the cab) with good results, but I got curious while running on mile long rows about which might perform better.

I found this post that suggests Stanley could work better at higher speeds, greater that 2kmh, since I’m planting at 6 mph most of the time I figured that qualifies as higher speeds.

Steering Algorithms

Pure Pursuit (PP) uses the curvature of a circular arc that connects the rear axle location to a goal point on the path ahead of the vehicle. Pure Pursuit was originally designed for fighter plane pilots and tracking. Stanley is a nonlinear feedback function of the cross track error measured from the center of the front axle to the nearest path point for which exponential convergence can be calculated. PP draws arcs to keep the pivot point on the line, Stanley tries to keep the steer axle on the…

For myself however I couldn’t seem to get Stanley to perform as well, no matter what I did with the settings. The biggest issue I had is even on flat ground, it would just sit to the side of the line going through the field, anywhere from 2-10" I saw, and not do anything to get itself back on the line. Switched back to pure pursuit and I pulled itself to the line immediately!

[EdwardC]

I’ve seen a lot of people state that Pure Pursuit is the better in v5 onwards, but personally I’ve always had too much oscillation with it, whereas Stanley performs perfectly. I’m mostly using it for drilling at around 8-12km/h and my antenna is mounted on my bonnet over the front axle.

I suspect that at the end of the day I never quite got the settings right for pure pursuit, but seeing as stanley worked with minimal tweaks, that is what I’ve stuck with.