Vehicle yaw/roll stability control with semi-active suspension

• US 7,571,039 B2
• Filed: 08/08/2006
• Issued: 08/04/2009
• Est. Priority Date: 08/08/2006
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations Incorporated (General Motors Company)
• Inventors: Moshchuk, Nikolai K., Chen, Shih-Ken, Chen, Cheng-Foo
• Primary Examiner(s): Tran; Khoi
• Assistant Examiner(s): Peche; Jorge O
• Application Number:
  US11/463,052
• Publication Number:
  US 20080040000A1
• Time in Patent Office: 1,092 Days
• Field of Search: 701/37, 701/38, 701/41, 701/42, 701/48, 701/70, 701/69, 701/72, 701/91, 180/197, 180/408, 180/233, 180/252, 180/253, 180/280, 180/282, 180/410, 180/423, 180/446, 180/41, 280/5.5, 280/5.01, 280/5.02, 280/5.04, 280/5.06, 280/5.07, 280/5.08, 280/5.51
• US Class Current: 701/38
• CPC Class Codes: B60G 17/0152 characterised by the action on a particular type of suspension unit B60G17/01941 takes precedence
• CPC Class Codes: B60G 17/0162 mainly during a motion involving steering operation, e.g. cornering, overtaking B60G17/0164 takes precedence
• CPC Class Codes: B60G 2202/20 Type of damper
• CPC Class Codes: B60G 2400/0521 Roll rate
• CPC Class Codes: B60G 2400/0523 Yaw rate
• CPC Class Codes: B60G 2400/104 lateral or transversal with regard to vehicle
• CPC Class Codes: B60G 2400/204 Vehicle speed
• CPC Class Codes: B60G 2800/0124 Roll-over conditions
• CPC Class Codes: B60G 2800/9124 Roll-over protection systems, e.g. for warning or control
• CPC Class Codes: Y10S 180/901 Devices for traversing vertical surfaces

Abstract

A rollover avoidance system for changing the damping characteristics of suspension dampers at each wheel of a vehicle so as to mitigate the potential for vehicle rollover. The system includes a plurality of vehicle parameter sensors for measuring vehicle parameters and providing vehicle parameter signals. The system also includes a controller for generating a damper suspension command signal for each damper using the vehicle parameter signals. The controller considers a roll control factor representing a rollover condition of the vehicle and a yaw stability control factor representing a yaw condition of the vehicle to set the damping of the dampers to mitigate the potential for vehicle rollover.

Claims

1. A rollover avoidance system for changing the damping characteristics of suspension dampers at each wheel of a vehicle to mitigate a potential rollover condition, said system comprising:

a speed sensor providing a vehicle parameter speed signal of the speed of the vehicle;

a roll rate sensor providing a vehicle parameter roll rate signal of the roll rate of the vehicle;

a lateral acceleration sensor for providing a vehicle parameter lateral acceleration signal of a lateral acceleration of the vehicle;

a yaw rate sensor for providing a vehicle parameter yaw rate signal of the yaw rate of the vehicle;

a hand-wheel angle sensor for providing a vehicle parameter hand-wheel angle signal of the angle of a vehicle hand-wheel;

a rollover indicator processor for calculating a roll stability indicator signal;

a dynamic command processor for generating a desired stability command signal based on the vehicle parameter signals for a desired stiffness of the dampers; and

a closed-loop controller responsive to vehicle parameter signals, the calculated roll stability indicator signal and the desired stability command signal, said closed-loop controller calculating an understeer or oversteer signal based on whether the vehicle is in an understeer or oversteer condition and a yaw stability control factor based on a yaw rate error signal and a side-slip error signal, said closed-loop controller further determining a roll error signal as the difference between the desired stability command signal and the calculated rollover stability indicator signal, said closed-loop controller also calculating a gain signal as a function of the vehicle speed signal, said closed-loop controller further calculating a closed-loop roll control factor based on the gain signal and the roll error signal, said closed-loop controller also determining a front to rear damper distribution of the damping characteristics of the suspension dampers based on the yaw rate error signal and the understeer or oversteer signal, said closed-loop controller generating a damper suspension command signal for each damper based on the front to rear distribution signal and the closed-loop roll control factor or the yaw stability control factor.

2. The system according to claim 1 wherein the closed-loop controller uses the yaw stability control factor or the roll control factor to generate the damper command signals depending on which is larger.

3. The system according to claim 1 wherein the closed-loop controller uses predetermined different gain signal depending on the magnitude of the roll stability indicator signal.

4. The system according to claim 1 further comprising an open-loop controller, said open-loop controller calculating an open-loop roll control factor based on the lateral acceleration signal, said system further comprising an adder that adds the open-loop roll control factor and the closed-loop roll control factor to generate a total roll control factor to determine the suspension command signals for each damper.

5. The system according to claim 4 wherein the closed-loop controller determines the suspension command signals as:

K_LF=0.5K_TFR

K_RF=K_LF

K_LR=0.5K_T(1−

FR)

K_RR=K_LR

where K_LF is the damping command signal for the damper at the left front wheel, K_RF is the damping command signal for the damper at the right front wheel, K_LR is the damping command signal for the damper at the left rear wheel, K_RR is the damping command signal for the damper at the right rear wheel, K_T is the added open-loop and closed-loop roll control factor or the yaw stability control factor, and FR is the front to rear damper distribution.

6. The system according to claim 1 wherein the dampers are semi-active magneto-rheological dampers.

7. The system according to claim 1 wherein the closed-loop controller determines the front to rear damper distribution of the damping characteristics of the suspension dampers using look-up tables.