A good control claim names a problem the rest of the field is still pretending doesn't exist. Waymo's grant US11125881B2 ("Lidar-based trailer tracking," issued September 21, 2021; inventors Mingcheng Chen, Christian Lauterbach, Benjamin Pitzer, Peter Morton) names this one: an autonomous tractor doesn't know exactly where its own trailer is. The claim tracks the trailer's pose relative to the tractor using LiDAR. It's a self-perception problem, not an obstacle-perception one.
The mechanism uses LiDAR returns from the trailer to estimate articulation angle and position, then feeds that into vehicle control. G01S 17/66 (tracking by LiDAR) and 17/42 (beam-steering geometry) describe the sensing; B60W 30/18009 and the 10/04/10/20 powertrain-and-steering codes describe acting on it. The claim closes a loop from "where is my trailer" to "how do I steer and brake given that."
For the control beat, this is a perfect example of an autonomy edge case that only appears at the truck scale. A car has no trailer articulation to estimate; a tractor-trailer's swept path, blind spots, and stability all depend on knowing the trailer state precisely. By fencing the LiDAR-based estimate of that state, Waymo stakes out a control input that is specific to — and necessary for — autonomous trucking, the segment it was actively building toward.
From a portfolio view, this grant later spawned a 2025 continuation (US12352862B2, same title), which is itself a signal: a quiet continuation on trailer tracking four years later telegraphs sustained investment in the trucking autonomy line even as Waymo's public focus stayed on robotaxis. Watch the continuation, not just the announcement — the family geography is the roadmap.
Caveats. Trailer-angle estimation has prior art in conventional ADAS and trailer-assist systems; the inventive step is the LiDAR-based method tied to autonomous control, so claim 1 is specific about the sensing-to-control link. And the broad B60W codes describe the action, not the novelty. Read the independent claim for the exact estimation step.
For the file: a trucking-specific, self-perception control grant with a live continuation family. Pull US11125881B2 and its 2025 child on PatentBear, read claim 1 for the trailer-state estimation step, and treat the continuation as the tell that the trucking line stayed funded.