We are using BeamNG for force feedback evaluation and are experiencing unstable steering wheel behavior when the vehicle is at a standstill. This issue is resolved by adding base damping and friction to the FFB steering wheel. However, the optimal base values for damping and friction vary from vehicle to vehicle.
We are looking for a way to set these base values automatically, based on the vehicle’s steering parameters.
Is there an option to retrieve the basic parameters of the steering system that affect the instability and use them to calculate the optimal base damping and friction for the FFB wheel?
yes, oscillations at low speeds is still an issue we are working on. As you mention the behaviour is dependent on the vehicle and on the steering wheel hardware. Adding a small portion of damping directly at the wheel driver can reduce the oscillation significantly.
The most common type of steering is usually modelled with hydros in the steering rack position. Other vehicles may have more complex designs, such as a car with all-wheel-steering, articulated steering, brake-steer vehicles, etc. You can have a look at the Hydros docu to get a better understanding of the properties of hydros:
To get the steering information during runtime, you can look at v.data.hydros[i], while i is the index (starting with 0). On steering systems with a pitman arm, like in trucks, the steering actuator is rotational by a torsionHydro. You can find the information here v.data.torsionHydros[i].
Hydros are also used for other actuating parts of the vehicle as you can see in the documentation. Check v.data.hydros[i].inputSource == "steering_input" to make sure this hydro is used for steering.
However, identify the right parameter to reduce steering oscillation is not trivial, because it depends on so many factors like tire properties, steering kinematics and ratio, axle geometry and kinematics, inertias of wheels, etc.
Thank you for the additional information regarding the hydraulics.
Unfortunately, I was not able to find a dependency between beamDamp and beamStiff and the initial damping and friction values, which would worked. Therefore, I used an empirical approach.
I had to use higher damping and friction values to stabilize the steering wheel when the vehicle was at a standstill. However, at higher vehicle speeds, it didn’t feel very good. So, I reduced the damping depending on the velocity. It felt better, but instability still occurred when initiated.
