Abstract: A system for controlling an internal combustion engine. The system includes engine shutdown/restart means and energy storage means configured for supplying power to an associated active vehicle suspension system when the engine is shut down. A controller is configured for controlling the shutdown/restart means responsive to an energy state of the energy storage means.

Abstract: A method for controlling a driveline having a transmission clutch includes locking the clutch before a driveline lash crossing occurs; maintaining a locked clutch during the lash crossing; after the lash crossing occurs, increasing a clutch capacity at a slower rate than a driveline twist torque rate; and after the lash crossing occurs, producing clutch slip by controlling engine torque and clutch capacity such that engine torque exceeds clutch capacity.

Abstract: A method for controlling a driveline having a transmission clutch includes locking the clutch before a driveline lash crossing occurs; maintaining a locked clutch during the lash crossing; after the lash crossing occurs, increasing a clutch capacity at a slower rate than a driveline twist torque rate; and after the lash crossing occurs, producing clutch slip by controlling engine torque and clutch capacity such that engine torque exceeds clutch capacity.

Abstract: An engine control system controls engine torque to transition through the transmission and driveline's lash zone. The transmission and driveline's lash zone is indicated using information of the speed ratio across the torque converter. This information is then supplemented with information of the driver's request and vehicle speed so that engine torque is adjusted at various predetermined rates based on current operating conditions. As such, the system can reduce undesired drive feel that otherwise may occur as the system passes through the transmission and driveline's lash zone. By limiting the change of torque in this way, driveability, while at the same time maintaining acceptable performance response.

Abstract: An engine control system controls engine torque to transition through the transmission and driveline's lash zone. The transmission and driveline's lash zone is indicated using information of the speed ratio across the torque converter. This information is then supplemented with information of the driver's request and vehicle speed so that engine torque is adjusted at various predetermined rates based on current operating conditions. As such, the system can reduce undesired drive feel that otherwise may occur as the system passes through the transmission and driveline's lash zone. By limiting the change of torque in this way, driveability, while at the same time maintaining acceptable performance response.

Abstract: A method is described for estimating cylinder charge using either the throttle position or mass air flow sensor. The method saves calibration and development expenses by using the same manifold filling model approach regardless of which sensor, or combination of sensors, is used.

Abstract: A control system parameter monitor determines a difference between a desired and estimated or measured parameter value, applies a weighting factor to the difference, and selects a control strategy based on the weighted difference. The weighting factor generally reflects the confidence in the accuracy of the parameter value determined by the parameter monitor. The weighting factor may be determined based on one or more engine or ambient operating conditions or parameters, or based on statistical analyses of monitor values and/or control system parameter values, for example. In one embodiment, an engine torque monitor for an electronic throttle control system uses percent torque deviation and rate of change to select an appropriate weighting factor and determine whether a deviation between desired and estimated or measured torque selects an alternative control strategy.

Abstract: A method is described for estimating cylinder charge using either the throttle position or mass air flow sensor. The method saves calibration and development expenses by using the same manifold filling model approach regardless of which sensor, or combination of sensors, is used.

Abstract: An engine air/fuel control system responsive to an electrically heated exhaust gas oxygen sensor. Electrical power is supplied to the sensor by a feedback control system responsive to peak-to-peak measurement in the sensor output. Peak-to-peak measurements are averaged over a predetermined number of sample times and the resulting average value compared to a deadband. When the average measurement is above, within, or below the deadband, electrical power to the heater is, respectively, reduced, held constant, or decreased.

Abstract: An engine air/fuel control system includes an apparatus and method for adaptively setting an initialization period preceding closed loop fuel control. During the initialization period, fuel delivered to the engine is modulated by a periodic waveform. A high voltage signal associated with the high output state of an exhaust gas oxygen sensor and a low voltage signal associated with the low voltage state of the exhaust gas oxygen sensor are sampled. When the difference between these signals exceeds a preselected value, the initialization period is terminated and closed loop fuel control is actuated.

Abstract: An engine air/fuel control system includes an apparatus and method for adaptively learning a reference voltage. Fuel delivered to the engine is trimmed by a feedback variable provided by integrating a two-state signal resulting from a comparison between the reference voltage and the exhaust gas oxygen sensor output. Each sample period of a microprocessor, a high voltage signal and low voltage signal are generated which track the outer envelope of the sensor signal. Calculation of a midpoint between high and low voltage signals provides the reference which instantaneously tracks the midpoint of the sensor signal.