Patent ID: 8538649

Claim:
In a torque converter having a pump that is rotatably driven by an internal combustion engine and that is fluidly coupled to a turbine, and a lockup clutch connected between the pump and the turbine, a method for managing accumulator effects during engagement of the lockup clutch, the method comprising: determining inertia of the engine, determining torque applied by the engine to the pump, determining rotational speed of the turbine, selecting a pump speed profile that reduces rotational speed of the pump from a first speed to the rotational speed of the turbine, determining a pump acceleration profile based on the pump speed profile, controlling engagement of the lockup clutch as a function of (i) the inertia of the engine, (ii) the torque applied by the engine to the pump, (iii) the rotational speed of the turbine, (iv) the pump speed profile, (v) and the pump acceleration profile, monitoring deceleration of the pump, determining a maximum deceleration of the pump as a function of monitored values of the deceleration of the pump, and temporarily holding constant the pump speed profile if the monitored deceleration of the pump rises at least a threshold value above the maximum deceleration of the pump.