Vehicle suspension control with compensation for yaw correcting active brake control

• US 6,181,997 B1
• Filed: 04/01/1999
• Issued: 01/30/2001
• Est. Priority Date: 04/01/1999
• Status: Expired due to Fees

• Current Assignee: BWI Company Limited SA (Shougang Corporation)
• Original Assignee: Delphi Technologies, Inc. (BorgWarner Incorporated)
• Inventors: Badenoch, Scott Wilson, Fratini, Albert Victor, Connair, Karen Marie, Hamilton, Harold David, Shal, David Andrew
• Primary Examiner(s): Cuchlinski, Jr., William A.
• Assistant Examiner(s): ARTHUR JEANGLAUDE, GERTRUDE
• Application Number:
  US09/283,055
• Time in Patent Office: 670 Days
• Field of Search: 701/1, 701/37, 701/38, 701/72, 701/83, 280/5.512, 280/5.513, 280/5.515
• US Class Current: 701/37
• CPC Class Codes: B60G 17/015 the regulating means comprising electric or electronic elements B60G17/002, B60G17/005 take precedence
• CPC Class Codes: B60G 2400/202 Piston speed; Relative velocity between vehicle body and wheel
• CPC Class Codes: B60G 2400/252 vertical
• CPC Class Codes: B60G 2500/10 Damping action or damper
• CPC Class Codes: B60G 2600/14 Differentiating means, i.e. differential control
• CPC Class Codes: B60G 2600/181 Signal modulation; pulse-width, frequency-phase
• CPC Class Codes: B60G 2800/215 by applying a braking action on each wheel individually
• CPC Class Codes: B60G 2800/93 Skid or slide control [ASR]

Abstract

A vehicle suspension system is responsive to an active brake signal from a brake system indicating the application of a greater braking force to one front corner brake than to the other front corner brake to affect vehicle yaw rate. The vehicle suspension system determines the relative velocities of the front corner suspension adjacent the front corner brake receiving the greater braking force and the diagonally opposed rear corner suspension and further determines a compression damping command for the front corner suspension and a rebound damping command for the rear corner suspension. While the active brake signal is present, the suspension control applies the compression damping command for the front corner suspension when its relative velocity indicates that it is in compression. While the active brake signal is present, the suspension control also applies the rebound damping command for the rear corner suspension when its relative indicates that it is in rebound.

Claims

1. A method of controlling a front corner suspension and a diagonally opposed rear corner suspension in a vehicle having a brake system with two front corner brakes and brake control means effective at times to modify vehicle yaw rate by applying a greater braking force to one of the front corner brakes adjacent the front corner suspension than to the other of the front corner brakes and generate an active brake signal while so doing, the method comprising the steps:

receiving the active brake signal;

determining a relative velocity of the front corner suspension and a relative velocity of the diagonally opposed rear corner suspension;

determining a compression damping command for the front corner suspension and a rebound damping command for the diagonally opposed rear corner suspension;

while the signal is received, applying the compression damping command to the front corner suspension when the relative velocity thereof indicates that it is in compression; and

while the signal is present, applying the rebound damping command to the diagonally opposed rear corner suspension when the relative velocity thereof indicates that it is in rebound.

2. A method of controlling a front corner suspension damper and a diagonally opposed rear corner suspension damper in a vehicle having a suspension damper at each corner thereof and a brake system with two front corner brakes and brake control means effective at times to modify vehicle yaw rate by applying a greater braking force to one off the front corner brakes adjacent the front corner suspension than to the other of the front corner brakes and generate an active brake signal while so doing, the method comprising the steps:

receiving the active brake signal;

determining a relative velocity of each of the suspension dampers and deriving from the determined relative velocities a demand force command for each of the dampers;

applying each of the derived demand force commands to its respective damper only when a comparison of the direction of the demand force command with the sensed relative velocity of the damper indicates that a force corresponding to the demand force command can be effectively exerted by the damper;

determining an active brake compression damping command for the front corner suspension damper adjacent the one of the front corner brakes and a relative velocity of the diagonally opposed rear corner suspension damper;

while the signal is received, applying the compression damping command to the front corner suspensions when the relative thereof indicates that it is in compression; and

while the signal is present, applying the rebound damping command to the diagonally opposed rear corner suspension when the relative velocity thereof indicates that it is in rebound.

3. A vehicle suspension system for use on a vehicle with a brake system having two front corner brakes and a brake control responsive to a vehicle dynamic sensor to apply a greater braking force to one of the front corner brakes than to the other of the front corner brakes and generate an active brake signal when so applying the greater braking force, the suspension system comprising:

two front corner suspensions;

two rear corner suspensions; and

a suspension control computer comprising, in combination;

means for receiving the active brake signal,

means for determining a relative velocity of one of the front corner suspensions adjacent the one of the front corner brakes and a relative velocity of one of the rear corner suspensions diagonally opposing the one of the front corner suspensions,

means for determining a compression damping command for the one of the front corner suspensions and determining a rebound damping command for the one of the rear corner suspensions,

means effective, while the active brake signal is received, for applying the compression damping command to the one of the front corner suspensions when the relative velocity of the one of the front corner suspensions indicates that it is in compression, and

means effective, while the signal is received, for applying the rebound damping command to the one of the rear corner suspensions when the relative velocity for the one of the rear corner suspensions indicates that it is in rebound.

4. A vehicle suspension system for use on a vehicle with a brake system having two front corner brakes and a brake control responsive to a vehicle dynamic sensor to apply a greater braking force to one of the front corner brakes than to the other of the front corner brakes and generate an active brake signal when so applying the greater braking force, the suspension system comprising:

two front corner suspensions each comprising a front damper;

two rear corner suspensions each comprising a rear damper;

relative velocity sensors at each of front and rear dampers;

means for deriving demand force commands for each of the two front corner suspensions and two rear corner suspensions in response to signals from the relative velocity sensors;

means for applying the derived demand force commands to the front and rear dampers only when a comparison of the direction of the demand force command for a damper with the sensed relative velocity of the damper indicates that a force corresponding to the demand force command can be effectively exerted by the damper;

means for receiving the active brake signal;

means for determining an active brake compression damping command for one of the front corner suspensions adjacent the one of the front corner brakes and determining an active brake rebound damping command for one of the rear corner suspensions diagonally opposing the one of the front corner suspensions;

means effective, while the active brake signal is received, for applying the active brake compression damping command to the one of the front corner suspensions when the relative velocity of the one of the front corner suspensions indicates that it is in compression; and

means effective, while the signal is received, for applying the active brake rebound damping command to the one of the rear corner suspensions when the relative velocity of the one of the rear corner suspensions indicates that it is in rebound.