System for detecting surface profile of a driving road

• US 6,718,248 B2
• Filed: 06/19/2002
• Issued: 04/06/2004
• Est. Priority Date: 06/19/2002
• Status: Expired due to Term

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Lu, Jianbo, Brown, Todd Allen
• Primary Examiner(s): Nguyen, Tan Q.
• Assistant Examiner(s): Tran, Dalena
• Application Number:
  US10/175,579
• Publication Number:
  US 20030236606A1
• Time in Patent Office: 657 Days
• Field of Search: 701/70, 701/90, 701/200, 701/213, 701/72, 701/110, 701/38, 701/37, 701/45, 701/220, 702/141, 702/151, 340/440, 180/282, 180/197
• US Class Current: 701/70
• 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 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 2400/0521 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 2400/106 longitudinal with regard to vehicle, e.g. braking
• CPC Class Codes: B60G 2400/204 Vehicle speed
• CPC Class Codes: B60G 2400/82 Ground surface
• CPC Class Codes: B60G 2401/12 Strain gauge
• CPC Class Codes: B60G 2800/0124 Roll-over conditions
• CPC Class Codes: B60G 2800/019 Inclination due to load distribution or road gradient
• CPC Class Codes: B60G 2800/0192 longitudinal with regard to vehicle
• CPC Class Codes: B60G 2800/0194 transversal with regard to vehicle
• CPC Class Codes: B60G 2800/702 Improving accuracy of a sensor signal
• CPC Class Codes: B60G 2800/9124 Roll-over protection systems, e.g. for warning or control
• CPC Class Codes: B60G 2800/92 ABS - Brake Control
• CPC Class Codes: B60G 2800/922 EBV - Electronic brake force distribution
• CPC Class Codes: B60G 2800/96 ASC - Assisted or power Steering control
• CPC Class Codes: B60T 2210/22 Banked curves
• CPC Class Codes: B60T 8/1755 Brake regulation specially adapted to control the stability of the vehicle, e.g. taking into account yaw rate or transverse acceleration in a curve road vehicle drive control systems for control of driving stability otherwise than by controlling a particular sub-unit B60W30/02
• CPC Class Codes: B60W 2520/105 : Longitudinal acceleration
• CPC Class Codes: B60W 2520/125 : Lateral acceleration
• CPC Class Codes: B60W 2520/14 : Yaw
• CPC Class Codes: B60W 2520/16 : Pitch
• CPC Class Codes: B60W 2520/18 : Roll
• CPC Class Codes: B60W 2520/28 : Wheel speed
• CPC Class Codes: B60W 2552/00 : Input parameters relating to infrastructure
• CPC Class Codes: B60W 2552/15 : Road slope, i.e. the inclination of a road segment in the longitudinal direction
• CPC Class Codes: B60W 30/04 : related to roll-over prevention
• CPC Class Codes: B62D 7/159 : characterised by computing methods or stabilisation processes or systems, e.g. responding to yaw rate, lateral wind, load, road condition
• CPC Class Codes: G01C 21/166 : Mechanical, construction or arrangement details of inertial navigation systems

Abstract

A control system (18) has a roll angular rate sensor (34), a yaw angular rate sensor (28), a lateral acceleration sensor (32), a longitudinal acceleration sensor (36), and four wheel speed sensors (20). The controller (26) determines a relative pitch angle and relative roll angle using the lateral acceleration signal, the longitudinal acceleration signal and the roll rate signal; a first flatness index using the roll angular rate signal, the yaw angular rate signal, the relative roll angle and a relative pitch angle; a steady state pitch angle using the vehicle speed and the longitudinal acceleration, and a steady state roll angle using the lateral acceleration, speed, and yaw rate. The controller (26) determines a second flatness index using the steady state pitch angle, the relative pitch angle, the yaw rate, the steady state roll angle and a relative roll angle.

Claims

1. A control system for an automotive vehicle having a vehicle body comprising:

a first angular rate sensor generating a first angular rate signal corresponding to a first angular motion of the vehicle body;

a second angular rate sensor generating a second motion signal corresponding to a second angular motion of the vehicle body;

a lateral acceleration sensor generating a lateral acceleration signal corresponding to a lateral acceleration of a center of gravity of the vehicle body;

a longitudinal acceleration sensor generating a longitudinal acceleration signal corresponding to the longitudinal acceleration of the center of gravity of the vehicle body;

a wheel speed sensor generating a wheel speed signal corresponding to a wheel speed of the vehicle; and

a controller coupled to said first angular rate sensor, said second angular rate sensor, said lateral acceleration sensor, said longitudinal acceleration sensor, and said wheel speed sensor, said controller determining a first flatness index and a second flatness index from the first angular rate signal, the second angular rate signal, the lateral acceleration signal and the longitudinal acceleration signal, and the speed signal, said controller determining a road slope or pitch angle and a road bank angle in response to the first flatness index and the second flatness index.

2. A system as recited in claim 1 wherein said first angular rate sensor is one selected from the group of a yaw rate sensor, a pitch rate sensor and a roll rate sensor and said second angular rate sensor comprises is one selected from the group of a yaw rate sensor, a pitch rate sensor and a roll rate sensor, said second sensor being different than the first sensor.

3. A control system for an automotive vehicle having a vehicle body comprising:

a roll angular rate sensor generating a roll angular rate signal corresponding to an roll angular motion of the vehicle body;

a yaw angular rate sensor generating a yaw rate signal corresponding to a yaw motion of the vehicle body;

a lateral acceleration sensor generating a lateral acceleration signal corresponding to a lateral acceleration of a center of gravity of the vehicle body;

a longitudinal acceleration sensor generating a longitudinal acceleration signal corresponding to the longitudinal acceleration of the center of gravity of the vehicle body;

a wheel speed sensor generating a wheel speed signal corresponding to a wheel speed of the vehicle; and

a controller coupled to said roll angular rate sensor, said yaw angular rate sensor, said lateral acceleration sensor, said longitudinal acceleration sensor, and said wheel speed sensor, said controller determining a relative pitch angle and relative roll angle as a function of the lateral acceleration signal, the longitudinal acceleration signal and the roll rate signal, determining a first flatness index as a function of the roll angular rate signal, the yaw angular rate signal, the relative roll angle and a relative pitch angle, said controller determining a steady state pitch angle as a function of the vehicle speed and the longitudinal acceleration, said controller determining a steady state roll angle as a function of lateral acceleration, vehicle speed and yaw rate, said controller determining a second flatness index as a function of the steady state pitch angle, the relative pitch angle, the yaw rate, the steady state roll angle and a relative roll angle.

4. A control system as recited in claim 3 further comprising a safety system coupled to said controller, said controller generating a control signal to said safety system as a function of the first flatness index and the second flatness index.

5. A control system as recited in claim 4 wherein said safety system comprises an active brake control system.

6. A control system as recited in claim 4 wherein said safety system comprises an active rear steering system.

7. A control system as recited in claim 4 wherein said safety system comprises an active front steering system.

8. A control system as recited in claim 4 wherein said safety system comprises an active anti-roll bar system.

9. A control system as recited in claim 4 wherein said safety system comprises an active suspension system.

10. A method controlling an automotive vehicle comprising:

estimating a first flatness index indicative of road flatness;

estimating a second flatness index indicative of road flatness;

determining a road pitch slope in response to the first flatness index and the second flatness index; and

determining a road bank angle in response to the first flatness index and the second flatness index.

11. A method as recited in claim 10 further comprising the step of controlling a safety device as a function of the bank angle and the pitch slope of the driving road.

12. A method as recited in claim 10 wherein the safety device comprises a yaw control system.

13. A method as recited in claim 10 wherein the safety device comprises a rollover stability control system.

14. A method as recited in claim 10 wherein determining a road pitch slope in response to the first flatness index and the second flatness index and determining a road bank angle in response to the first flatness index and the second flatness index are performed when the first flatness index and the second flatness index are above a predetermined threshold.

15. A method as recited in claim 10 further comprising:

determining a roll angular rate signal, a yaw angular rate signal, a relative roll angle and a relative pitch angle;

wherein the first flatness index is a function of a first flatness index as a function of the roll angular rate signal, the yaw angular rate signal, the relative roll angle and a relative pitch angle •

.

16. A method as recited in claim 10 further comprising:

determining a steady state pitch angle, a relative pitch angle, a yaw rate, a steady state roll angle and a relative roll angle;

wherein the second flatness index is a function of the steady state pitch angle, the relative pitch angle, the yaw rate, the steady state roll angle and a relative roll angle.

17. A method of controlling an automotive vehicle comprising:

measuring a roll rate of the vehicle body;

measuring a lateral acceleration of the vehicle body;

measuring the longitudinal acceleration of the vehicle body;

measuring the yaw rate of the vehicle body;

measuring a vehicle speed;

determining a relative pitch angle and relative roll angle as a function of the lateral acceleration, the longitudinal acceleration and the roll rate signal;

determining a first flatness index as a function of the roll angular rate, the yaw angular rate, the relative roll angle and a relative pitch angle;

determining a steady state pitch angle as a function of the vehicle speed and the longitudinal acceleration;

determining a steady state roll angle as a function of lateral acceleration, longitudinal speed and yaw rate;

a determining a second flatness index as a function of the steady state pitch angle, the relative pitch angle, the yaw rate, the steady state roll angle and a relative roll angle; and

generating a control signal as a function of the first flatness index and the second flatness index.

18. A method as recited in claim 17 activating a safety device as a function of the road bank angle and the road pitch angle.

19. A method as recited in claim 17 wherein said step of activating a safety device comprises one selected from the group consisting of an active brake control system, an active rear steering system, an active front steering system, an active anti-roll bar system, and an active suspension system.