US 5,939,794 AGranted

Engine control system for hybrid vehicle

AssigneeNippon Soken, Inc.

InventorsShoji Sakai, Hironori Asa, Sadahisa Onimaru, Mitsuo Inagaki

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Abstract

A series hybrid vehicle includes a generator to be driven by an engine, a battery to be charged by the output power of the generator, and a motor for driving the vehicle using the output power sent from the generator and the output power sent from the battery. In an engine control system for the series hybrid vehicle, the values of power demanded by the vehicle when the vehicle is running (i.e., power demand values) are derived based on various engine operation indicative sensor signals, and a running state of the vehicle is estimated based on a frequency distribution of the power demand and a mean value of such power demand values. The system selects one of prestored control patterns depending on the estimated vehicle running state and controls the engine based on the selected control pattern so as to further control the output power of the generator. The system is also applicable to a parallel hybrid vehicle.

Claims17

Dependent claims

An engine control system for a hybrid vehicle having an engine, a motor and a power storage unit for supplying power to said motor, said system comprising:

a plurality of prestored engine operation command patterns;
deriving means for (A) deriving a representation of the operating state of the vehicle from a plurality of power demand values and (B) outputting the representation of the operating state of the vehicle;
and
control means for (C) selecting one of said prestored engine operation command patterns according to the representation of the operating state of the vehicle and (D) adjusting an operation of the engine based on said selected pattern;
wherein each of the power demand values is derived from a sensor signal indicating an operating condition of the vehicle that has arisen during the period of time for which the vehicle has been continuously running;
and
wherein the representation of the operating state of the vehicle outputted by said deriving means is based on at least a frequency distribution of the power demand values.

4 more elements

Dependencies are inferred from the claim text.