Institute for Physical AI @ BMI · a demonstration
The drone leaned to move; the humanoid stepped. Tell this rover to go one metre to its left, though, and it does something neither of them would — because a wheel obeys a rule you have felt every time you parallel-parked. Watch it try. The gold ring is where you told it to be; the dashed line is the path it is not allowed to take. The source runs the real constraint, so it cannot lie to you.
Provenance. A rolling wheel can move only along the direction it points. Written down, the body-frame sideways velocity ẋ·sinθ − ẏ·cosθ is identically zero — a nonholonomic constraint. There is simply no control input that points left: the rover steers and drives, so to reach a pose beside it, it must trace a curve (the parallel-parking maneuver). The board runs a real pose-regulation controller live; every frame it reports its sideways velocity, and it is always zero. All numbers computed by the Institute's open drive core. The 3D model is illustrative; the numbers are exact.