Response time and performance of a high-torque magneto-rheological fluid limited slipdifferential clutch

Abstract

In this study, the response time and system characterization analyses of a high-torquemagneto-rheological (MR) fluid limited slip differential (LSD) clutch are presented. Theresponse time of the clutch is examined based on the objective of keeping the relativevelocity difference of the shafts of the clutch less than a predetermined threshold value. Theexperimental setup allows the application of an external disturbance to the system, so thatthe relative velocity difference exceeds the threshold value. A velocity-based, closed-loopcontrol system is designed and tested. Additionally, system identification experiments areperformed to determine system parameters such as bearing friction coefficients, dryand viscous torque coefficients. These parameters are utilized in the theoreticalresponse time analyses of the MR fluid LSD clutch. It is demonstrated that theoverall response time of the system varies between 20 and 65 ms as a function ofoperating velocity and electromagnet current, including the response times of thecontroller, solenoid inductance and MR fluid and inertia effects. The responsetime reduces by increasing solenoid current and increasing the operating velocity.