Simultaneous estimation of driveline dynamics and backlash size for control design

The ldquoShunt and shufflerdquo-phenomenon at rapid torque transients in a vehicle driveline greatly influences the drivability. A dynamic model that can describe both the traversing of the backlash and the following poorly damped oscillations is proposed. It is experimentally shown to have good predictive capability which is important for control design. The model includes backlash to avoid underestimating the oscillation amplitude after rapid large accelerator pedal movements (ldquotip-in/outrdquo). The parameter estimation results are obtained using only the existing engine torque signal and engine and vehicle speed measurements.