VEHICLE BRAKING/DRIVING FORCE CONTROL APPARATUS

• US 20150158493A1
• Filed: 10/15/2014
• Published: 06/11/2015
• Est. Priority Date: 12/09/2013
• Status: Active Grant

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: NAKATSU, Masatoshi
• Granted Patent: US 9,227,637 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B60W 10/08 including control of electric propulsion units, e.g. motors or generators
• CPC Class Codes: B60W 10/192 electric brakes
• CPC Class Codes: B60W 10/22 including control of suspension systems
• CPC Class Codes: B60W 20/00 Control systems specially adapted for hybrid vehicles hybrid vehicle design, B60K6/00; electric vehicles B60L
• CPC Class Codes: B60W 2030/206 related or induced by the engine
• CPC Class Codes: B60W 2510/109 Direction of power flow
• CPC Class Codes: B60W 2520/403 between front and rear axle
• CPC Class Codes: B60W 2720/403 between front and rear axle
• CPC Class Codes: B60W 30/18127 Regenerative braking
• CPC Class Codes: B60W 30/20 Reducing vibrations in the driveline
• CPC Class Codes: B60Y 2300/77 Torque reversal, e.g. avoid clunks when changing between driving and coasting
• CPC Class Codes: Y02T 10/72 Electric energy management in electromobility

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.

Claims

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,

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.