1. Field of the Invention
The present invention relates to a vehicle drive control device for a vehicle. More particularly, the present invention relates to a vehicle drive control device provided with an electric generator and a voltage increasing circuit for eliminating generator output deficiencies when they occur.
2. Background Information
In hybrid vehicles driven with both an engine and a motor, the generator output and, thus, the electric power supplied to the motor is often deficient when the rotational speed of the engine is slow, such as when the vehicle is starting into motion from a stopped condition. A typical example is when the vehicle is starting into motion on an upward slope (other examples include starting into motion on a muddy road, a sandy road, or a snowy road) and the electric generator cannot generate sufficient electricity because the engine speed is low. In such a case, the vehicle may not start into motion appropriately in accordance with the acceleration requested by the driver.
In U.S. patent application Publication No. 2004/0044458 (based on Japanese Patent Application No. 2002-259160), a vehicle driving force control apparatus is disclosed whereby generator output deficiencies are eliminated by increasing the engine rotational speed in a four-wheel drive system employing an electric generator and an electric motor. Since the electric generator is driven by the engine, it cannot generate sufficient electricity if the engine rotational speed is low. Therefore, the vehicle driving force control apparatus was configured to prevent the generator output from declining by maintaining a high engine rotational speed without upshifting the gear ratio of the transmission.
In view of the above, it will be apparent to those skilled in the art from this disclosure that there exists a need for an improved vehicle drive control device. This invention addresses this need in the art as well as other needs, which will become apparent to those skilled in the art from this disclosure.