Vehicle drive control apparatus, and vehicle drive control method

Patent metadata

Field	Value
Publication number	US-9308807-B2
Application number	US-201314380275-A
Country	US
Kind code	B2
Filing date	Feb 18, 2013
Priority date	Feb 27, 2012
Publication date	Apr 12, 2016
Grant date	Apr 12, 2016

Abstract

A total driving force according to an acceleration request of a driver is secured, and deterioration of acceleration performance, such as slowness at the time of starting, is suppressed. When an engine torque is converted into motor torque through a generator, a power distribution ratio α from the engine torque to the motor torque is set. Additionally, as a road surface gradient θ is smaller on an upward slope side, the power distribution ratio α is limited. Specifically, when the road surface gradient θ is more than or equal to a predetermined θ1 on the upward slope side, the power distribution ratio α is set to a predetermined maximum value α MAX . When the road surface gradient θ is less than or equal to θ2, which is smaller than θ1, on the upward slope side, the power distribution ratio α is set to a minimum value α MIN .

First claim

The invention claimed is:

1. A vehicle drive control apparatus, comprising:
an engine configured to drive a main drive wheel;
an electric generator configured to generate electric power with power of the engine;
an electric motor configured to drive an auxiliary drive wheel with the electric power generated by the electric generator;
a gradient detecting unit configured to detect a road surface gradient of an upward slope road; and
a distribution ratio setting unit configured to set a power distribution ratio of power of the electric motor distributed from the power of the engine, when a part of the power of the engine is distributed to the power of the electric motor through the electric generator,
wherein the power distribution ratio setting unit is configured to set a first power distribution ratio according to an accelerator operation of a driver, set a second power distribution ratio such that as the road surface gradient is smaller, the power distribution ratio is smaller, and set a smaller one of the first power distribution ratio and the second power distribution ratio, as a final power distribution ratio.

2. The vehicle drive control apparatus according to claim 1 ,
wherein when the road surface gradient is larger than or equal to a predetermined first threshold value on an upward slope side, the power distribution ratio setting unit is configured to set the power distribution ratio to a predetermined maximum value,
wherein when the road surface gradient is smaller than or equal to a second threshold value, which is smaller than the first threshold value, on the upward slope side, the power distribution ratio setting unit is configured to set the power distribution ratio to a predetermined minimum value, and
wherein when the road surface gradient falls within a range from the first threshold value to the second threshold value on the upward slope side, as the road surface gradient is smaller on the upward slope side, the power distribution ratio setting unit is configured to set the power distribution ratio to be smaller within the range from the maximum value to the minimum value.

3. A vehicle drive control method, comprising:
driving a main drive wheel by an engine;
generating electric power, by an electric generator, by obtaining power of the engine;
driving an auxiliary drive wheel by an electric motor with the electric power generated by the electric generator;
setting a power distribution ratio of power of the electric motor distributed from the power of the engine, when a part of the power of the engine is distributed to the power of the electric motor through the electric generator; and
setting a first power distribution ratio according to an accelerator operation of a driver, setting a second power distribution ratio such that as a road surface gradient is smaller, the power distribution ratio is smaller, and setting a smaller one of the first power distribution ratio and the second power distribution ratio, as a final power distribution ratio.

Assignees

• Nissan Motor

Inventors

• Hane Shougo

Classifications

• B60L2240/14

  Acceleration · CPC title

• B60L50/16

  with provision for separate direct mechanical propulsion · CPC title

• B60K6/52

  Driving a plurality of drive axles, e.g. four-wheel drive · CPC title

• B60W2720/403

  between front and rear axle · CPC title

• B60L2240/12

  Speed · CPC title