Abstract: In a vehicle having a voltage regulated electric alternator driven by an engine for supplying power to drive electrical loads and to charge a vehicle battery, a method of maintaining battery state-of-charge includes adaptively learning a system voltage set-point during a first mode of engine operation probabalistically resulting in an electrical system operative in set-point regulation. The method further determines from the adaptively learned system voltage set-point and a present system voltage during a second mode of engine operation that the electrical system is operative in auto-regulation. Idle speed is controlled in response to the regulation state of the electrical system to maintain the system in set-point regulation to ensure adequate battery charge or minimal battery discharge during the second mode of engine operation.

Abstract: An air/fuel ratio controller for an internal combustion engine including two memories each having numbers stored at locations addressed by engine operating points with the locations addressed by the engine operating points being updated during closed loop operation in accord with the value of a closed loop adjustment of the air/fuel ratio. Each memory location in the first memory is updated during operation of the engine at the corresponding operating point in accord with an update time constant having a value so that the number stored tracks adjustment value producing the predetermined desired closed loop air/fuel ratio during varying values of engine operating parameters. Each memory location in the second memory is updated during operation of the engine at the corresponding operating point in accord with an update time constant having a value so that the number stored is the average of the values producing the predetermined closed loop air/fuel ratio during varying values of engine operating parameters.

Abstract: An air/fuel ratio controller for an internal combustion engine including a memory having numbers stored at locations addressed by engine operating points with the locations addressed by the engine operating points being updated during closed loop operation in accord with the value of a closed loop adjustment of the air/fuel ratio. Each memory location in the memory is updated during operation of the engine at the corresponding operating point in accord with an update time constant having a value so that the number stored tracks adjustment value producing the predetermined desired closed loop air/fuel ratio during varying values of engine temperature. The update time constant is varied directly with the value of engine temperature so that the rate of adjustment of the numbers in the memory is greater during engine warmup where engine temperature increases rapidly. The memory is used during closed loop operation to preset the closed loop adjustment at least when the engine first operates at an operating point.