Tire pressure vehicle speed limiting

• US 20030033072A1
• Filed: 08/09/2002
• Published: 02/13/2003
• Est. Priority Date: 12/05/2000
• Status: Active Grant

• Current Assignee: Lear Corporation
• Original Assignee: Lear Corporation
• Inventors: Nantz, John S., Ghabra, Riad, Tang, Qingfeng, Khreizat, Salman
• Granted Patent: US 6,671,609 B2
• Time in Patent Office: Days
• US Class Current: 701/93
• CPC Class Codes: B60K 31/00 Vehicle fittings, acting on a single sub-unit only, for automatically controlling vehicle speed, i.e. preventing speed from exceeding an arbitrarily established velocity or maintaining speed at a particular velocity, as selected by the vehicle operator fittings acting on two or more sub-units B60W30/14; speedometers G01P; systems or devices for controlling speed in general G05D13/00 ; in traffic anti-collision system for road vehicles G08G1/16
• CPC Class Codes: B60T 8/172 Determining control parameters used in the regulation, e.g. by calculations involving measured or detected parameters B60T8/17551 takes precedence
• CPC Class Codes: B60W 2050/021 Means for detecting failure or malfunction
• CPC Class Codes: B60W 2530/20 Tyre data
• CPC Class Codes: B60W 2710/0616 Position of fuel or air injector
• CPC Class Codes: B60W 30/146 Speed limiting

Abstract

Tire over- or under-inflation can create problems in vehicle operation. To limit the effects of out-of-range tire pressure, vehicle speed is automatically controlled if the vehicle speed is not appropriate for either or both of measured tire air pressure and measured tire temperature.

Claims

1. A method of limiting vehicle speed comprising:

sensing the air pressure in at least one tire;

sensing temperature in the at least one tire;

sensing vehicle speed;

determining at least one threshold based on at least one parameter of vehicle operation;

determining if the vehicle speed is appropriate for each tire based on the sensed tire air pressure, the sensed tire temperature and on each determined threshold; and

automatically controlling vehicle speed if the vehicle speed is not appropriate for each tire.

2. A method of limiting vehicle speed as in claim 1 wherein reducing vehicle speed comprises controlling the delivery of fuel to an engine powering the vehicle.

3. A method of limiting vehicle speed as in claim 1 wherein reducing vehicle speed comprises controlling the delivery of spark to an engine powering the vehicle.

4. A method of limiting vehicle speed as in claim 1 wherein reducing vehicle speed comprises controlling the delivery of air to an engine powering the vehicle.

5. A method of limiting vehicle speed as in claim 1 wherein reducing vehicle speed comprises controlling the revolution rate of a rotating power plant powering the vehicle.

6. A method of limiting vehicle speed as in claim 1 wherein reducing vehicle speed comprises controlling the delivery of electrical power to a motor powering the vehicle.

7. A method of limiting vehicle speed as in claim 1 wherein the at least one threshold comprises a maximum pressure threshold, the vehicle speed being not appropriate for the tire if the tire pressure is greater than the maximum pressure threshold.

8. A method of limiting vehicle speed as in claim 1 wherein the at least one threshold comprises a minimum pressure threshold, the vehicle speed being not appropriate for the tire if the tire pressure is less than the minimum pressure threshold.

9. A method of limiting vehicle speed as in claim 1 wherein the at least one threshold comprises a maximum temperature threshold, the vehicle speed being not appropriate for the tire if the tire temperature is greater than the maximum temperature threshold.

10. A method of limiting vehicle speed as in claim 1 wherein the at least one threshold comprises a minimum temperature threshold, the vehicle speed being not appropriate for the tire if the tire temperature is less than the minimum temperature threshold.

11. A method of limiting vehicle speed as in claim 1 wherein the at least one parameter of vehicle operation consists of at least one from a set including vehicle load, vehicle load distribution, four-wheel drive mode, towing mode, automatic suspension mode, traction control operation, automatic brake system control, tire location, air pressure in other tires, temperature in other tires, ambient air pressure, and ambient temperature.

12. A method of limiting vehicle speed as in claim 1 wherein the at least one parameter of vehicle operation comprises vehicle speed.

13. A method of limiting vehicle speed as in claim 1 further comprising indicating automatic speed reduction to a vehicle operator.

14. A system for limiting vehicle speed comprising:

at least one tire pressure sensor generating a pressure signal based on the pressure of air within a tire;

at least one tire temperature sensor generating a temperature signal based on the temperature within the tire;

a vehicle speed sensor generating a signal based on vehicle speed;

a power plant causing the vehicle to move at the vehicle speed based on power plant control signals; and

control logic in communication with each tire pressure sensor, the tire temperature sensor, the vehicle speed sensor and the power plant, the control logic generating at least one power plant control signal to automatically control vehicle speed if the vehicle speed is not appropriate for at least one tire based on the sensed tire air pressure, sensed tire temperature and on at least one vehicle operating condition.

15. A system for limiting vehicle speed as in claim 14 further comprising an indicator controlled by the control logic, the indicator indicating automatic speed reduction to a vehicle operator.

16. A system for limiting vehicle speed as in claim 14 wherein the control logic automatically reduces vehicle speed if the tire pressure is less than a minimum value based on the at least one vehicle operating condition.

17. A system for limiting vehicle speed as in claim 14 wherein the control logic automatically reduces vehicle speed if the tire pressure is greater than a maximum value based on the at least one vehicle operating condition.

18. A system for limiting vehicle speed as in claim 14 wherein the control logic automatically reduces vehicle speed if the tire temperature is less than a minimum value based on the at least one vehicle operating condition.

19. A system for limiting vehicle speed as in claim 14 wherein the control logic automatically reduces vehicle speed if the tire temperature is greater than a maximum value based on the at least one vehicle operating condition.

20. A system for limiting vehicle speed as in claim 14 wherein each tire pressure sensor generates a signal based on self diagnosis, the control logic inhibiting automatic vehicle speed reduction based on sensed tire air pressure for a tire with a pressure sensor generating a failed self diagnosis signal.

21. A system for limiting vehicle speed as in claim 20 further comprising an indicator controlled by the control logic, the indicator indicating the tire pressure sensor failed diagnostic testing.

22. A system for limiting vehicle speed as in claim 14 wherein the at least one vehicle operating condition consists of at least one from a set including vehicle load, vehicle load distribution, four-wheel drive mode, towing mode, automatic suspension mode, traction control operation, automatic brake system control, tire location, air pressure in other tires, temperature in other tires, ambient air pressure, and ambient temperature.

23. A system for limiting vehicle speed as in claim 14 wherein the at least one vehicle operation condition comprises vehicle speed.

24. A method of limiting vehicle speed comprising:

determining tire pressure in at least one tire based on pressure sensed within the tire;

determining vehicle speed;

automatically limiting vehicle maximum speed if the vehicle speed is not appropriate for each tire based on the sensed tire air pressure;

determining tire temperature in the at least one tire based on temperature sensed within the tire;

automatically limiting vehicle maximum speed if the vehicle speed is not appropriate for each tire based on the sensed tire temperature; and

automatically limiting vehicle maximum speed if the vehicle speed is not appropriate for each tire based on the sensed tire temperature and based on the sensed tire pressure.