Abstract: An engine crankshaft torque observer (10) and method of operation. An engine combustion process (14) is modeled (26) to develop modeled pressure estimates of combustion chamber pressures in engine cylinders according to certain engine inputs, such as fuel (20), EGR (22), and timing (24), that influence combustion chamber pressures. Kinematics (16) relating reciprocal motion of pistons in the engine cylinders to an engine crankshaft and engine friction (18) relating running friction of the engine to engine crankshaft rotation are also modeled (28; 30). A processor processes the certain engine inputs through the combustion process model to develop modeled pressure estimates which are processed through the kinematics model to develop modeled positive torque contribution due to combustion processes and through the friction model to develop modeled torque loss due to running friction.

Abstract: A control system comprising a processor develops data controlling a combustion engine and a dynamoelectric machine arranged to interact with the engine to modify the torque output of the engine. An observer (10) develops observed data that comprises estimated engine speed, estimated crankangle, and estimated engine output torque represented as an estimated average value torque component on which is superimposed an estimated alternating polarity ripple torque component whose mean value over a time interval of interest is substantially zero. The estimated alternating polarity ripple torque component is an input to a torque controller (102) for the dynamoelectric machine which causes the machine to contribute, in real time, torque that substantially cancels the alternating polarity ripple torque component in the crankshaft torque.

Abstract: A control assembly 12 for use within a vehicle 10 having an engine 14 and which selectively controls the speed of the engine 14 in order to increase fuel efficiency and to effect relatively smooth starting and stopping of the engine. Particularly, in one embodiment, control assembly 12 cooperatively operates with a starter/alternator assembly 20 and is adapted for use with hybrid vehicles employing a start/stop powertrain assembly, wherein fuel efficiency is increased by selectively stopping engine operation when the vehicle has stopped.