i am doing a graduation project for my bachelor on Steer-by-Wire, i have to make a modeling and simulation on simulink. i reached the idea that the torque output from the motor that actuates the steering axles to rotate the wheel around the z - axis (Yaw) changes with the velocity of the car (not proportianal ) i am trying to find this relation to be set in the controller in order to control the torque output , i hope that someone can help me where i can find this relation
I don't like your chances of finding that information. It is dependent on way too many variables like vehicle weight and intended purpose, steering geometry, tire and wheel size, tire compound, aspect ratio and intended purpose.
I suspect that information is gathered by auto company Engineers from years of test data and is probably closely guarded IP.
Just a guess though.
Since it is only simulation, why not sneak up on it by starting with a guess and working down or up in Torque until it fails or stops failing.