## I need help (Steer-by-Wire Grad. Project)

Hello there,

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

thank you :)
 Blog Entries: 2 Recognitions: Gold Member Science Advisor I don't think I could quantify it for you, but it's nonlinear with speed not only due to friction but also due to gyroscopic forces on the tires at higher speeds. It's relatively simple to calculate the required force at zero velocity, and from there required force goes down. So if your system can put out enough force to turn the tire while stationary, it can put out enough force at any speed. The rest is just a response curve based on speed. My wife's car has an electric power steering system which varies assist force based on speed- it puts out maximum force at zero to about 10mph, and reduces as speed increases. By the time you're doing 65 mph, assist force has dropped significantly.
 Thank you very much for the replay, that was very helpful info, and saves a lot of time and search. any more advice would be welcome

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