We have built up an APM 2.5, external compass/GPS, 1/10 scale car into an autonomous vehicle. It’s working OK and navigating courses except for an oversteer problem. Using the latest APM rover and Mission Planner software.
As it moves toward a waypoint when it turns the wheels to correct the direction of travel it turns too much. So it ends up zig zagging down what should be a straight line. With curse throttle set at about a walking pace it zig/zabs about one foot in four feet. When cruse throttle is set higher it becomes a real problem because it takes side to side excursions of three or four feet before the next over correction.
The mechanical steering in this car is quite tight so this is not a mechanical problem.
I suspect this can be solved by PID tuning, perhaps reducing steering P.
What is the best way to tune out this oversteer?
Jim
jim at coloradosatellite.com