Rough road detection

• US 20060136111A1
• Filed: 12/20/2004
• Published: 06/22/2006
• Est. Priority Date: 12/20/2004
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations LLC (General Motors Company)
• Inventors: Robert, Dominique, Scelers, Herve, Tissot, Pascal
• Granted Patent: US 7,739,019 B2
• Time in Patent Office: Days
• US Class Current: 701/65
• CPC Class Codes: B60W 2552/35 Road bumpiness, e.g. potholes
• CPC Class Codes: F16H 59/66 Road conditions, e.g. slope, slippery
• CPC Class Codes: F16H 61/14 Control of torque converter lock-up clutches
• CPC Class Codes: F16H 61/66272 characterised by means for controlling the torque transmitting capability of the gearing

Abstract

A rough road detection system for a vehicle comprises a first acceleration sensor that measures vertical acceleration of a component of the vehicle. An adaptive acceleration limits module determines a first acceleration limit based upon a speed of the vehicle. A limit comparison module generates a rough road signal based on a comparison of the first acceleration limit from the adaptive acceleration limits module and the measured acceleration from the first acceleration sensor.

Claims

1. A rough road detection system for a vehicle comprising:

a first acceleration sensor that measures vertical acceleration of a component of the vehicle;

an adaptive acceleration limits module that determines a first acceleration limit based upon a speed of the vehicle; and

a limit comparison module that generates a rough road signal based on a comparison of the first acceleration limit from the adaptive acceleration limits module and the measured acceleration from the first acceleration sensor.

2. The rough road detection system of claim 1 further comprising a second acceleration sensor, wherein the first acceleration sensor measures vertical acceleration of a front left wheel of the vehicle, and the second acceleration sensor measures vertical acceleration of a front right wheel of the vehicle.

3. The rough road detection system of claim 2 wherein the adaptive acceleration limits module also determines a second acceleration limit, wherein the first acceleration limit is an upper bound of vertical acceleration and the second acceleration limit is a lower bound of vertical acceleration.

4. The rough road detection system of claim 3 further comprising an acceleration calculator that reduces vertical acceleration data from the first and second acceleration sensors to a single computed acceleration value.

5. The rough road detection system of claim 4 wherein the limit comparison module determines the computed acceleration value is within the acceleration limits if the computed acceleration value is greater than the lower bound and less than the upper bound.

6. The rough road detection system of claim 5 wherein the adaptive acceleration limits module selects the first and second acceleration limits from an acceleration limits table based upon the speed of the vehicle.

7. The rough road detection system of claim 6 wherein the computed acceleration value is either of the measured vertical acceleration of the front left wheel and the measured vertical acceleration of the front right wheel, whichever has the greater absolute value.

8. A road condition aware system for a vehicle comprising the rough road detection system of claim 1 and further comprising:

a continuously variable transmission (CVT) that includes a belt having a tension adjustment; and

a control module that determines the tension adjustment on the belt in the CVT when the rough road signal is received from the limit comparison module.

9. The road condition aware system of claim 8 wherein the control module determines the tension adjustment based upon the measured vertical acceleration.

10. A road condition aware system for a vehicle comprising the rough road detection system of claim 1 and further comprising:

an automatic transmission including a torque converter having a slip adjustment; and

a control module that determines the slip adjustment in the torque converter of the automatic transmission when the rough road signal is received from the limit comparison module.

11. A road condition aware system for a vehicle comprising the rough road detection system of claim 1 and further comprising:

a vibration-sensitive sensor; and

a control module that includes a filter that receives information from the vibration-sensitive sensor and that adjusts parameters of the filter when the rough road signal is received from the limit comparison module.

12. The road condition aware system of claim 11 wherein the vibration-sensitive sensor is a throttle pedal position sensor.

13. The road condition aware system of claim 11 wherein the vibration-sensitive sensor is an engine speed (revolutions per minute) sensor.

14. A vibration-sensitive powertrain adjustment system for a vehicle comprising:

an acceleration sensor that measures vertical acceleration of a component of the vehicle;

a rough road detection system that analyzes the measured acceleration and generates a road condition signal;

a control module that generates an operating parameter adjustment signal based upon a speed of the vehicle and the road condition signal; and

a vibration-sensitive system that adjusts an operating parameter based on the operating parameter adjustment signal.

15. The vibration-sensitive powertrain adjustment system of claim 14 wherein the vibration-sensitive system is a mechanical device, and the operating parameter is a mechanical parameter.

16. The vibration-sensitive powertrain adjustment system of claim 14 wherein the vibration-sensitive system is a continuously variable transmission (CVT), and the operating parameter is a tension on a belt within the CVT.

17. The vibration-sensitive powertrain adjustment system of claim 14 wherein the vibration-sensitive system is an automatic transmission, and the operating parameter is slippage of a torque converter within the automatic transmission.

18. The vibration-sensitive powertrain adjustment system of claim 14 wherein the vibration-sensitive system is a sensor system including a filter, and the operating parameter is a parameter of the filter.

19. The vibration-sensitive powertrain adjustment system of claim 18 wherein the sensor system comprises a throttle pedal position sensor.

20. The vibration-sensitive powertrain adjustment system of claim 18 wherein the sensor system comprises an engine speed sensor.

21. A road condition aware control system for a continuously variable transmission (CVT) comprising:

a first acceleration sensor that measures vertical acceleration of a component of the vehicle;

an adaptive acceleration limits module that determines a first acceleration limit based upon a speed of the vehicle;

a limit comparison module that compares the first acceleration limit from the acceleration limits module with the measured acceleration from the first acceleration sensor,

wherein the limit comparison module outputs a rough road signal if the measured acceleration is outside of the first acceleration limit;

a pressure offset module that determines and outputs a pressure offset; and

a line pressure module that increases clamping pressure on a belt of the CVT by the pressure offset received from the pressure offset module when the rough road signal is received from the limit comparison module.

22. The rough road detection system of claim 21 further comprising a second acceleration sensor, wherein the first acceleration sensor measures vertical acceleration of a front left wheel of the vehicle, and the second acceleration sensor measures vertical acceleration of a front right wheel of the vehicle.

23. The rough road detection system of claim 22 further comprising a second acceleration limit, wherein the first acceleration limit is an upper bound of vertical acceleration and the second acceleration limit is a lower bound of vertical acceleration.

24. The rough road detection system of claim 23 further comprising an acceleration calculator that reduces vertical acceleration data from the first and second acceleration sensors to a single computed acceleration value.

25. The rough road detection system of claim 24 wherein the limit comparison module determines the computed acceleration value is within the acceleration limits if the computed acceleration value is greater than the lower bound and less than the upper bound.

26. The rough road detection system of claim 25 wherein the adaptive acceleration limits module selects the first and second acceleration limits from an acceleration limits table based upon the speed of the vehicle.

27. The rough road detection system of claim 26 wherein the pressure offset module selects the pressure offset from a table based upon the computed acceleration value.

28. The rough road detection system of claim 27 wherein the computed acceleration value is either of the measured vertical acceleration of the front left wheel and the measured vertical acceleration of the front right wheel, whichever has the greater absolute value.