Closed-loop bucket loading, four control cases

Four wheel loaders dug together in about a million particles, each on a different controller. Watching force in the bucket rams and easing the curl won 11% more material for 31% less energy than a fixed schedule tuned to match it.

We coupled a 31-body articulated machine, driven through its cylinders, to VeloxSim's granular solver. Four machines running at once, about a million soil particles interacting directly with the buckets.

Then we closed the loop. The controller watches the force in the bucket cylinders and eases the curl as the material loads up, instead of forcing the bucket closed and levering the machine off the ground. Against a fixed schedule tuned to match it: 11% more material loaded, 31% less energy.

Our first result looked more than 5x better than the baseline, but that baseline was a schedule we had tuned by hand. When we copied the closed-loop controller's own motion into a fixed schedule, most of the gap closed. What was left came down to one thing: easing the bucket curl when the rams load up. It took four control cases to find that out.

Simulated with NDEM, our real-time granular engine.