Drive force control method for four-wheel drive vehicle

• US 20050217921A1
• Filed: 03/30/2005
• Published: 10/06/2005
• Est. Priority Date: 03/31/2004
• Status: Active Grant

• Current Assignee: Honda Motor Co., Ltd. (Honda Motor Company)
• Original Assignee: Honda Motor Co., Ltd. (Honda Motor Company)
• Inventors: Mori, Atsushi, Shibahata, Yasuji
• Granted Patent: US 7,264,077 B2
• Time in Patent Office: Days
• US Class Current: 180/433
• CPC Class Codes: B60K 17/35 including arrangements for suppressing or influencing the power transfer, e.g. viscous clutches differential gearing with locking devices F16H48/20
• CPC Class Codes: B60K 23/0808 for varying torque distribution between driven axles, e.g. by transfer clutch
• CPC Class Codes: B60W 2520/125 Lateral acceleration
• CPC Class Codes: B60W 2520/14 Yaw
• CPC Class Codes: B60W 2540/18 Steering angle
• CPC Class Codes: B60W 2710/105 Output torque

Abstract

A drive force control method for a four-wheel drive vehicle including a torque distributing mechanism capable of changing a drive force distribution ratio between front and rear wheels and a drive force distribution ratio between right and left front wheels or between right and left rear wheels. This method includes the steps of increasing the drive force distribution ratio of the rear wheels to the front wheels according to an increase in absolute value of a lateral G signal, and increasing the drive force distribution ratio of a turning outer wheel as one of the right and left front wheels or one of the right and left rear wheels to a turning inner wheel as the other. A lateral G sensor signal is corrected by an estimated lateral G signal calculated according to a steering angle and a vehicle speed to obtain a control lateral G signal, which is used as the lateral G signal.

Claims

1. A drive force control method for a four-wheel drive vehicle including a torque distributing mechanism capable of changing a drive force distribution ratio between front and rear wheels and a drive force distribution ratio between right and left front wheels or between right and left rear wheels, said drive force control method comprising the steps of:

detecting a lateral G to output a lateral G signal;

increasing the drive force distribution ratio of said rear wheels to said front wheels according to an increase in absolute value of said lateral G signal; and

increasing the drive force distribution ratio of a turning outer wheel as one of said right and left front wheels or one of said right and left rear wheels to a turning inner wheel as the other according to an increase in absolute value of said lateral G signal.

2. A drive force control method for a four-wheel drive vehicle according to claim 1, wherein:

said lateral G signal comprises a lateral G sensor signal;

said drive force control method further comprising the steps of;

calculating an estimated lateral G according to a steering angle and a vehicle speed; and

correcting said lateral G sensor signal by said estimated lateral G.

3. A drive force control method for a four-wheel drive vehicle according to claim 1, further comprising the steps of:

detecting an unstable condition of said vehicle; and

increasing the drive force distribution ratio of said front wheels to said rear wheels and decreasing the drive force distribution ratio of said turning outer wheel to said turning inner wheel when the unstable condition of said vehicle is detected.

4. A drive force control method for a four-wheel drive vehicle including a torque distributing mechanism capable of changing a drive force distribution ratio between front and rear wheels and a drive force distribution ratio between right and left front wheels or between right and left rear wheels, said drive force control method comprising the steps of:

detecting a lateral G to output a lateral G signal; and

increasing the drive force distribution ratio of a turning outer wheel to a turning inner wheel according to an increase in absolute value of said lateral G signal.