Automotive apparatus and method for dynamically determining centripetal force of a vehicle

• US 5,123,497 A
• Filed: 12/20/1990
• Issued: 06/23/1992
• Est. Priority Date: 12/20/1990
• Status: Expired due to Term

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Motor Company
• Inventors: Yopp, Wilford T., Mackool, Sam M.
• Primary Examiner(s): Rice, Kenneth R.
• Assistant Examiner(s): DICKSON, PAUL N
• Application Number:
  US07/631,120
• Time in Patent Office: 551 Days
• Field of Search: 180/141, 180/142, 180/170, 280/689, 280/772, 280/707, 364/424.01
• US Class Current: 180/422
• 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 2400/204 Vehicle speed
• CPC Class Codes: B60G 2400/40 Steering conditions
• CPC Class Codes: B60G 2400/42 Steering torque
• CPC Class Codes: B60G 2400/50 Pressure
• CPC Class Codes: B60G 2400/60 Load
• CPC Class Codes: B60G 2400/64 Wheel forces, e.g. on hub, spindle or bearing
• CPC Class Codes: B60G 2400/822 Road friction coefficient determination affecting wheel traction
• CPC Class Codes: B60G 2600/02 Retarders, delaying means, dead zones, threshold values, cut-off frequency, timer interruption
• CPC Class Codes: B60G 2600/60 Signal noise suppression; Electronic filtering means
• CPC Class Codes: B60G 2600/70 Computer memory; Data storage, e.g. maps for adaptive control
• CPC Class Codes: B60G 2800/24 Steering, cornering
• CPC Class Codes: B60G 2800/90 System Controller type
• CPC Class Codes: B60G 2800/92 ABS - Brake Control
• CPC Class Codes: B60T 2260/06 Active Suspension System
• CPC Class Codes: B60T 8/17551 determining control parameters related to vehicle stability used in the regulation, e.g. by calculations involving measured or detected parameters
• CPC Class Codes: B60W 40/109 Lateral acceleration
• CPC Class Codes: B62D 6/04 responsive only to forces disturbing the intended course of the vehicle, e.g. forces acting transversely to the direction of vehicle travel

Abstract

An apparatus and method for determining the centripetal force of an automotive vehicle operating on a roadway includes a vehicle speed measuring mechanism and a steering force measuring mechanism. Information regarding vehicle speed and steering force are fed into a processor which determines the centripetal force of the vehicle.

Claims

1. An apparatus for determining the centripetal force of an automotive vehicle operating on a roadway, comprising;

vehicle speed measuring means comprising means for producing a first signal representing the speed at which said vehicle is being operated;

steering force measuring means comprising means for producing a second signal representing the steering force required to operate the steering system of said vehicle at said measured vehicle speed; and

processor means for determining the centripetal force of said vehicle, with said processor means comprising means for receiving said first and second signals and means for deriving from said signals a third signal representing the magnitude of said centripetal force.

2. An apparatus according to claim 1 wherein said processor means determines the centripetal force of said vehicle by matching measured vehicle speed and steering force with one of a plurality of reference pairs comprising vehicle speed and steering force values, where each of such reference pairs corresponds to a predetermined value of centripetal force.

3. An apparatus according to claim 2 wherein said processor means comprises a read-only memory containing said reference pairs and said third signal values.

4. An apparatus according to claim 1 wherein said processor means determines centripetal force by operating upon said first and second signals with a mathematical function contained in said processor.

5. An apparatus according to claim 1 wherein said vehicle speed measuring means comprises a signal generator driven by a powertrain of said vehicle.

6. An apparatus according to claim 1 wherein said steering force measuring means comprises a pressure transducer interposed between a steering gear for steering said road wheel and a hydraulic pump for powering said steering gear.

7. An apparatus according to claim 1 wherein said steering force measuring means comprises a torque sensor for sensing torque applied to a driveshaft of a steering gear for steering said road wheel.

8. A vehicle control apparatus, comprising:

vehicle speed measuring means for measuring the speed of said vehicle and for producing a first signal representing said speed;

steering force measuring means for measuring the steering force required to operate the steering system of said vehicle at said measured vehicle speed and for producing a second signal presenting said force;

processor means for determining the centripetal force of said vehicle, with said processor means comprising means for receiving said first and second signals and means for deriving from said signals a third signal representing the magnitude of said centripetal force; and

emergency control means responsive to said third signal for operating a control system within said vehicle.

9. An apparatus according to claim 8 wherein said control system comprises means for regulating the operation of a brake system incorporated in said vehicle.

10. An apparatus according to claim 8 wherein said emergency control system comprises means for warning the driver of said vehicle that centripetal force is greater than a predetermined value.

11. An apparatus according to claim 8 wherein said control system comprises means for limiting the maximum speed of the vehicle.

12. An apparatus according to claim 8 wherein said control system comprises means for limiting the maximum forward acceleration of the vehicle.

13. An apparatus according to claim 8 wherein said control system comprises means for operating an adjustable suspension system.

14. An apparatus according to claim 13 wherein said control system comprises means for controlling damping produced by said adjustable suspension system.

15. An apparatus according to claim 8 wherein said control system comprises means for controlling the output of a power assist device associated with said steering system.

16. An apparatus according to claim 15 wherein said means for controlling the output of a power assist device associated with said steering system comprises a valve for limiting the magnitude of the assist produced by said power assist device.

17. A method for determining the centripetal force exerted on an automotive vehicle and for initiating a control system within said automotive vehicle having roadwheels, comprising the steps of:

measuring the speed of said vehicle;

measuring the steering force required to turn said roadwheels of said vehicle;

entering said vehicle speed and said steering force into a processor means;

comparing said measured vehicle speed and said measured steering force with one of a plurality of reference pairs stored in said processor means, each one of said reference pairs comprising vehicle speed and steering force values corresponding to a predetermined centripetal force value; and

initiating said control system within said vehicle when said centripetal force value exceeds a predetermined value.

18. A method according to claim 17, wherein said control system is operative to adjust the spring rate of a suspension unit of said vehicle.

19. A method according to claim 17, wherein said control system is operative to adjust the shock valving of a suspension unit of said vehicle.

20. A method according to claim 17, wherein said control system is operative to initiate a warning signal within said vehicle.

21. A method for controlling a steering assist device of a power steering system of an automotive vehicle having a pair of steerable roadwheels, comprising the steps of:

measuring the sped of said vehicle;

measuring the steering pressure within said steering system while turning said roadwheels of said vehicle, said pressure being measured by a pressure transducer;

determining a required steering assist value based upon said measured vehicle speed and said measured steering pressure; and

adjusting sad power assist device of said power steering system to meet said required steering assist value.