Braking and drive force control apparatus for a vehicle

• US 20060076740A1
• Filed: 09/26/2005
• Published: 04/13/2006
• Est. Priority Date: 10/07/2004
• Status: Active Grant

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Sugiyama, Mizuho
• Granted Patent: US 7,788,011 B2
• Time in Patent Office: Days
• US Class Current: 280/5.502
• CPC Class Codes: B60G 17/0195 characterised by the regulation being combined with other vehicle control systems conjoint control of vehicle sub-units including control of suspension systems B60W10/22
• CPC Class Codes: B60G 2200/14 with lateral arms
• CPC Class Codes: B60G 2204/182 Electric motor on wheel support
• CPC Class Codes: B60G 2300/50 Electric vehicles; Hybrid vehicles
• CPC Class Codes: B60G 2400/102 vertical
• CPC Class Codes: B60G 2400/206 Body oscillation speed; Body vibration frequency
• CPC Class Codes: B60G 2400/252 vertical
• CPC Class Codes: B60G 2800/014 Pitch; Nose dive
• CPC Class Codes: B60G 3/20 all arms being rigid
• CPC Class Codes: B60K 6/52 Driving a plurality of drive axles, e.g. four-wheel drive
• CPC Class Codes: B60L 15/20 for control of the vehicle or its driving motor to achieve a desired performance, e.g. speed, torque, programmed variation of speed
• CPC Class Codes: B60L 15/2009 for braking
• CPC Class Codes: B60L 2220/46 Wheel motors, i.e. motor connected to only one wheel
• CPC Class Codes: B60L 2240/46 related to wheels
• CPC Class Codes: B60L 2240/463 Torque
• CPC Class Codes: B60L 7/00 Electrodynamic brake systems for vehicles in general
• CPC Class Codes: B60W 10/08 including control of electric propulsion units, e.g. motors or generators
• CPC Class Codes: B60W 2520/16 Pitch
• CPC Class Codes: B60W 2710/083 Torque
• CPC Class Codes: B60W 30/20 Reducing vibrations in the driveline
• CPC Class Codes: Y02T 10/62 : Hybrid vehicles
• CPC Class Codes: Y02T 10/64 : Electric machine technologies in electromobility
• CPC Class Codes: Y02T 10/72 : Electric energy management in electromobility

Abstract

A braking and drive force control apparatus for a vehicle whose wheels are separately driven by electric motors. A controller calculates a drive force or a braking force to be applied to each wheel in accordance with the average sprung displacement and average sprung velocity of the vehicle body which are calculated based on sensed sprung acceleration. By adding the calculated drive force or braking force to the drive force at the time of running, at the time of bouncing of the vehicle body, a downwards force can be generated in the vehicle body which is rising, and an upwards force can be generated in the vehicle body which is descending. By applying an upwards or downwards force to each wheel so as to permit upwards and downwards vibration of the wheels, variations in the ground contact load can be suppressed.

Claims

1. A braking and drive force control apparatus for a vehicle which has four actuators which independently drive four wheels which are suspended on a vehicle body by a suspension apparatus and which can independently control the braking and drive forces generated by the four actuators, comprising:

a vehicle body upwards and downwards vibration sensing means which senses upwards and downwards vibration of the vehicle body; and

a braking and drive force control means which produces a difference in the braking and drive forces generated by the four actuators in accordance with the sensed upwards and downwards vibration of the vehicle body to thereby apply a force to the vehicle body in a direction for suppressing the upwards and downwards vibration of the vehicle body.

2. A braking and drive force control apparatus for a vehicle as claimed in claim 1, wherein the braking and drive force control means produces a difference in the braking and drive forces generated by the four actuators so as to generate forces on the front and rear wheels in opposite directions in the fore and aft direction of the vehicle to thereby generate a downwards force on the vehicle body when the vehicle body has risen and produces a difference in the braking and drive forces generated by the four actuators so as to generate forces on the front and rear wheels in opposite directions in the fore and aft direction of the vehicle to thereby generate an upwards force on the vehicle body when the vehicle body has descended.

3. A braking and drive force control apparatus for a vehicle as claimed in claim 1, wherein the vehicle body upwards and downwards vibration sensing means includes a sprung acceleration sensor which senses the sprung acceleration of the vehicle body in the upwards and downwards direction with respect to absolute space and a bouncing sensing means which senses bouncing of the vehicle body based on the sprung acceleration which was sensed, and

the braking and drive force control means includes a braking and drive force calculating means which calculates the braking and drive force to be generated by the four actuators in accordance with the sensed bouncing of the vehicle body and a drive force control means which drives and controls the four actuators in accordance with the calculated braking and drive force.

4. A braking and drive force control apparatus for a vehicle as claimed in claim 3, wherein the bouncing sensing means includes a sprung displacement calculating means which calculates the sprung displacement of the vehicle body in the upwards and downwards direction based on the sensed sprung acceleration and senses bouncing of the vehicle body when the calculated sprung displacement is at least a prescribed value.

5. A braking and drive force control apparatus for a vehicle which has four actuators which independently drive four wheels which are suspended on a vehicle body by a suspension apparatus and which can independently control the braking and drive forces generated by the four actuators, comprising:

a wheel upwards and downwards vibration sensing means which senses upwards and downwards vibration of each of the wheels; and

a braking and drive force control means which changes the braking and drive force generated by the actuator corresponding to each wheel in accordance with the sensed upwards and downwards vibration of the corresponding wheel and applies a force in the direction allowing upwards and downwards vibration of the corresponding wheel.

6. A braking and drive force control apparatus for a vehicle as claimed in claim 5, wherein the braking and drive force control means changes the braking and drive force which is generated by the actuator corresponding to a rising wheel so as to generate an upwards force in the wheel and which changes the braking and drive force generated by the actuator corresponding to a descending wheel so as to generate a downwards force in the wheel.

7. A braking and drive force control apparatus for a vehicle as claimed in claim 5, wherein the upwards and downwards vibration sensing means for each wheel senses the unsprung acceleration of the wheel in the upwards and downwards direction with respect to absolute space, and the braking and drive force control means includes a braking and drive force calculating means which calculates the braking and drive force to be generated by the actuator corresponding to each wheel in accordance with the sensed unsprung acceleration and a drive force control means which drives and controls the actuator in accordance with the calculated braking and drive force.