Tire contact load control system

• US 6,223,108 B1
• Filed: 05/22/1998
• Issued: 04/24/2001
• Est. Priority Date: 05/22/1997
• Status: Expired due to Fees

• Current Assignee: Honda Giken Kogyo Kabushiki Kaisha (Honda Motor Company)
• Original Assignee: Honda Giken Kogyo Kabushiki Kaisha (Honda Motor Company)
• Inventors: Izawa, Masaki, Oshida, Kei, Shibue, Hideaki
• Primary Examiner(s): Nguyen, Tan
• Assistant Examiner(s): Tran, Dalena
• Application Number:
  US09/083,717
• Time in Patent Office: 1,068 Days
• Field of Search: 701/36, 701/37, 701/38, 701/48, 701/69, 701/70, 701/71, 701/72, 701/73, 701/80, 701/89, 280/5.513, 280/5.512, 280/5.518, 280/5.504, 280/5.507, 280/124.157
• US Class Current: 701/36
• CPC Class Codes: B60G 17/0164 mainly during accelerating or braking
• 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 2400/102 vertical
• CPC Class Codes: B60G 2400/204 Vehicle speed
• CPC Class Codes: B60G 2400/208 of wheel rotation
• CPC Class Codes: B60G 2400/252 vertical
• CPC Class Codes: B60G 2400/51 in suspension unit
• CPC Class Codes: B60G 2600/182 Active control means
• CPC Class Codes: B60G 2800/22 Braking, stopping
• CPC Class Codes: B60G 2800/915 Suspension load distribution
• CPC Class Codes: B60G 2800/92 ABS - Brake Control
• CPC Class Codes: B60T 2260/06 Active Suspension System
• CPC Class Codes: B60T 8/17616 Microprocessor-based systems

Abstract

An active actuator is interposed between the unsprung mass and the sprung mass of a vehicle, and a controller selectively extends and retracts the actuator at a prescribed acceleration so as to selectively apply an additional contact load to the wheel by making use of the inertial force of the sprung mass and/or the unsprung mass of the vehicle. A particularly advantageous result can be achieved by increasing the tire contact load when the wheel is about to lock up when braking. The present invention can thus reduce the braking distance for the given road condition.

Claims

1. A vehicle tire contact load control system, comprising:

a wheel suspension system for supporting an unsprung mass including a wheel to a sprung mass including a vehicle body;

an active actuator interposed between said unsprung mass and said sprung mass;

means for computing a slip ratio of a wheel; and

a controller for extending said actuator at a prescribed acceleration so as to selectively apply an additional contact load to said wheel when a slip ratio computed by said computing means has exceeded a prescribed value.

2. A vehicle tire contact load control system according to claim 1, wherein said controller is adapted to apply said additional contact load to said wheel when a braking force is applied to said wheel, and said prescribed value consists of a value beyond which a braking force available to said wheel starts diminishing.

3. A vehicle tire contact load control system according to claim 2, wherein an antilock brake system is additionally provided in the vehicle, and said prescribed value is lower than a reference value at which said antilock brake system is activated.

4. A vehicle tire contact load control system according to claim 1, wherein said controller is adapted to apply said additional contact load to said wheel when a traction force is applied to said wheel, by the vehicle and said prescribed value consists of a value beyond which a traction force available to said wheel starts diminishing.

5. A vehicle tire contact load control system according to claim 1, further comprising means for determining a road condition, and said prescribed value is varied depending said road condition determined by said determining means.

6. A vehicle tire contact load control system according to claim 1, wherein said unsprung mass includes a plurality of wheels, said system includes a plurality of said active actuators, one said active actuator is interposed between said sprung mass and each said tire, and said controller independently extends each said actuator so that the contact load for each said wheel is increased at a desired timing.

7. A vehicle tire contact load control system according to claim 2, wherein said braking force is a fore-and-aft braking force.