Vehicle braking/driving force control apparatus

Patent metadata

Field	Value
Publication number	US-9227637-B2
Application number	US-201414514734-A
Country	US
Kind code	B2
Filing date	Oct 15, 2014
Priority date	Dec 9, 2013
Publication date	Jan 5, 2016
Grant date	Jan 5, 2016

Abstract

When a braking/driving force on each wheel is used for vehicle motion control, in order to reduce a noise generated by a zero cross of a motor torque, provided is a distribution setting part, which is to be applied to a vehicle configured so that a conversion rate of converting a braking/driving force on the wheel into a force in a vertical direction of a body by a suspension is different between a front wheel side and a rear wheel side. The distribution setting part sets distributions of a driver-requested driving force to front/rear wheels so as to be larger to the wheels coupled to the suspensions smaller in conversion rate than to the wheels coupled to the suspensions larger in conversion rate. As a result, a zero cross of a motor torque is restrained, resulting in a reduction in generation of a noise caused by a backlash of speed reduction gears.

First claim

What is claimed is:

1. A vehicle braking/driving force control apparatus, comprising:
a motor provided on each of a front left wheel, a front right wheel, a rear left wheel, and a rear right wheel, which is capable of transmitting a torque via gears to each of the wheels, thereby generating a braking/driving force on the each of the wheels;
a suspension for coupling the each of the front left wheel, the front right wheel, the rear left wheel, and the rear right wheel to a body, and converting the braking/driving force on the each of the wheels to a force in a vertical direction of the body;
target braking/driving force calculation means for calculating a target braking/driving force for the each of the wheels, the target braking/driving force including: a driver-requested distributed driving force acquired by distributing a driver-requested driving force set based on an operation amount by a driver to the each of wheels; and a control braking/driving force for the each of the wheels required for vehicle motion control; and
motor control means for controlling an operation of the motor by following the target braking/driving force,
the suspension being configured so that a conversion rate of converting the braking/driving force on the each of the wheels into the force in the vertical direction of the body is different between a front wheel side and a rear wheel side, wherein the motor control means includes the conversion rate pre-stored therein,
the target braking/driving force calculation means comprising distribution setting means for setting a distribution of the driver-requested driving force to the front wheels and the rear wheels so that a larger driver-requested driving force is distributed to the wheels coupled to the suspensions on a side smaller in the conversion rate than to the wheels coupled to the suspension on a side larger in the conversion rate.

2. A vehicle braking/driving force control apparatus according to claim 1 , wherein the distribution setting means sets, regarding the distribution of the driver-requested driving force to the front wheels and the rear wheels, a ratio of distribution to the wheels coupled to the suspensions on the side smaller in the conversion rate to a constant set distribution ratio more than 0.5 when the driver-requested driving force is less than a set driving force, and changes the ratio of distribution so that the ratio of distribution decreases within a range of the set distribution ratio or less as the driver-requested driving force increases when the driver-requested driving force is equal to or more than the set driving force.

3. A vehicle braking/driving force control apparatus according to claim 2 , wherein the distribution setting means uses, as the set distribution ratio, a value calculated when a sum of the conversion rate of the suspensions for the front wheels and the conversion rate of the suspensions for the rear wheels is set as a denominator and the conversion rate of the suspensions on the side larger in the conversion rate is set as a numerator.

4. A vehicle braking/driving force control device according to claim 1 further comprising vehicle speed acquisition means for acquiring a vehicle speed,
wherein the distribution setting means sets, regarding the distribution of the driver-requested driving force to the front wheels and the rear wheels, a ratio of distribution to the wheels coupled to the suspensions on the side smaller in the conversion rate to a value larger than 0.5 when the vehicle speed is less than a first set vehicle speed and sets the ratio of distribution to a value equal to or less than 0.5 when the vehicle speed is equal to or more than a second set vehicle speed, which is equal to or more than the first set vehicle speed.

Assignees

• Nakatsu Masatoshi
• Toyota Motor Co Ltd

Inventors

• Nakatsu Masatoshi

Classifications

• B60W2510/109

  Direction of power flow · CPC title

• B60W2520/403

  between front and rear axle · CPC title

• B60Y2300/77

  Torque reversal, e.g. avoid clunks when changing between driving and coasting · CPC title

• B60W10/08

  including control of electric propulsion units, e.g. motors or generators · CPC title

• B60W10/192

  electric brakes · CPC title