arche/diff-drive-rover

Differential-drive rover

A 2 kg rover on two driven wheels and a caster ball, with an encoder on each wheel, an IMU and a GPS. The navigator follows three waypoints — (1, 0), (1, 1), (0, 1) — by odometry: the distance from the encoders, the heading from the gyro. A heading loop turns it toward the next waypoint, a speed loop slows it in the turns and near the waypoint (0.5 m/s at most), and it stops at the last. The GPS is the truth: when odometry says a waypoint is reached, the navigator records how far the GPS says it is (miss, worst_miss).

| | | |---|---| | Plant | a free chassis, 2 wheel hinges with velocity servos (kv 0.2), a caster (ball joint), 2 encoders, IMU, GPS, 1 ms step | | Controller | odometry, heading and speed loops, 100 Hz; Driving → Arrived | | Requirements | REQ-RV-WAYPOINTS (within 0.1 m of each, in 15 s), REQ-RV-SPEED | | Test plan | TP-RV: three waypoints, the speed limit |

archec new my-rover --template diff-drive-rover     a project from it, yours to change
archec gen main.arche --target mujoco -o out
archec sim main.arche --plant out/mujoco/plant_bridge.py --test
python3 out/mujoco/plant_bridge.py --viewer

In MuJoCo (4.0): the last waypoint reached at 10.4 s, the GPS at most 0.073 m from a waypoint when odometry said it was there. The wheels are spheres, so that their frames need no turning; the ground is MuJoCo's default plane.