Patent ID: 8849530
Filing Date: 2014-09-30
Classification: F16H

Abstract:
1. A method for determining clutch control values during a power-on upshift in a vehicle having a controller, an oncoming clutch, an offgoing clutch, and a torque converter having a turbine, the method comprising: dropping a pressure command to the offgoing clutch to a calibrated holding pressure via the controller after onset of the power-on upshift; using proportional-integral-derivative (PID) logic of the controller to introduce a calibrated error into the pressure command to the offgoing clutch during a fill stage of the oncoming clutch to thereby cause a calibrated amount of slip to occur across the offgoing clutch, and a resultant threshold amount of flare to occur in a speed of the turbine; maintaining the calibrated amount of slip and the resultant threshold amount of flare at a constant level using the PID logic; recording a clutch pressure and a corresponding clutch torque of the offgoing clutch while maintaining the calibrated amount of slip and the resultant threshold amount of flare; determining a fill level of the oncoming clutch using a trajectory of an integrator term of the PID logic while maintaining the calibrated amount of slip and the resultant threshold amount of flare; and adjusting a control value of the oncoming or the offgoing clutch via the controller using at least one of the fill level, the recorded clutch pressure, and the recorded clutch torque.