Vehicle deceleration display system and calculation method

• US 7,155,329 B2
• Filed: 05/24/2004
• Issued: 12/26/2006
• Est. Priority Date: 05/24/2004
• Status: Expired due to Fees

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: General Motors of Canada Limited (General Motors Company)
• Inventors: Mepham, Dan W., Weigert, Norman Joseph
• Primary Examiner(s): BEAULIEU, YONEL
• Application Number:
  US10/852,446
• Publication Number:
  US 20050261819A1
• Time in Patent Office: 946 Days
• Field of Search: 701/70, 701 78- 79, 303/121, 303/138, 303/160, 340/425.5, 340/438
• US Class Current: 701/70
• CPC Class Codes: B60R 16/0232 for measuring vehicle parameters and indicating critical, abnormal or dangerous conditions

Abstract

A vehicle deceleration display system includes a serial data bus operable for communicating a plurality of sequentially-measured vehicle speed datums in a respective sequential manner. A control unit is operatively connected to the serial data bus and is operable for receiving and processing the vehicle speed data therefrom. The control unit is programmed to sequentially calculate vehicle deceleration values respectively corresponding with the sequential speed data to provide a variable output signal. The variable output signal corresponds with and varies in accordance with the sequential vehicle deceleration values. A variable display is connected to the control unit and varies in response to the deceleration values. A method of calculating and displaying vehicle deceleration values is also provided.

Claims

1. A vehicle deceleration display system comprising:

a serial data bus operable for communicating a plurality of sequentially measured vehicle speed datums in a respective sequential manner;

a control unit operatively connected to said serial data bus and operable for receiving and processing said vehicle speed data therefrom, wherein said control unit is programmed to sequentially calculate vehicle deceleration values respectively corresponding with said sequential vehicle speed data to provide a variable output signal which corresponds with and varies in accordance with said sequential vehicle deceleration values; and

a variable display operatively connected to said control unit, wherein said variable display varies in response to said output signal.

2. The vehicle deceleration display system of claim 1, wherein each datum is a measurement of the speed of an output shaft of a transmission on the vehicle;

and

wherein said control unit is further programmed for controlling said transmission using said sequential vehicle speed data.

3. The vehicle deceleration display system of claim 1, wherein each of said vehicle deceleration values (Dec_INST) is defined by the equation:

Dec_INST=(V_c−

V_p)/T, wherein V_c and V_P are consecutively-received vehicle speed data, wherein V_c is received subsequent to V_p, and T is the elapsed time between reception of said respective data.

4. The vehicle deceleration display system of claim 1, wherein each of said vehicle deceleration values represents an average of a number of sequentially calculated deceleration values:

5. The vehicle deceleration system of claim 1, wherein said control unit is programmed to calculate the difference between a first calculated vehicle deceleration value and a second calculated vehicle deceleration value, said second deceleration value being calculated based on later sequential speed data than said first deceleration value;

wherein said control unit provides said output signal varying in correspondence with said second deceleration value after a first amount of time K₁, when said second deceleration value is greater than said first deceleration value by a first amount and after a second amount of time K₂ when said second deceleration value is less than said first deceleration value by a second amount; and

wherein K₁ is different than K₂, such that said output signal varies to correspond with said second deceleration value at a different rate when vehicle deceleration is increasing than when vehicle deceleration is decreasing.

6. The vehicle deceleration system of claim 1, wherein said control unit is further programmed to compare said vehicle deceleration value with a minimum threshold value, and wherein said control unit does not provide said output signal when said vehicle deceleration value is less than said minimum threshold value, such that said variable display does not vary in response to deceleration values less than the minimum threshold value.

7. The vehicle deceleration system of claim 1, wherein said serial data bus is further operable for communicating vehicle stability data to said control unit including at least one of implementation of anti-lock brake system, implementation of a traction control system, occurrence of an understeer event and occurrence of a rollover event;

and

wherein said control unit provides said output signal at a preset level when said vehicle stability data is so communicated.

8. The vehicle deceleration system of claim 1, wherein said variable display comprises a plurality of light-emitting diodes (LEDs) arranged in an array and mounted on the rear of the vehicle, wherein said LEDs are illuminated in sequential pairs outward from a center of said array, the nmnber of sequential pairs illuminated being in increasing nonlinear proportion to the magnitude of said output signal.

9. The vehicle deceleration system of claim 8, wherein at least some of said LEDs are illuminated in response to application of a vehicle brake pedal, said LEDs illuminated in response to application of the brake pedal being generally centrally-located in the array.

10. A method comprising:

calculating vehicle deceleration values from sequentially-measured vehicle speed data received via a serial data bus; and

providing an output signal that varies in accordance with said calculated vehicle deceleration values.

11. The method of claim 10, further comprising:

varying a variable display in response to said output signal.

12. The method of claim 11, wherein said variable display comprises a plurality of light-emitting diodes (LEDs) arranged in an array and mounted on the rear of the vehicle;

and

wherein said varying said variable display includes illuminating said LEDs in sequential pairs outward from a center of said array, the number of sequential pairs illuminated being in increasing nonlinear proportion to the magnitude of said output signal.

13. The method of claim 10, wherein said vehicle speed data comprises a plurality of sequentially-measured speeds of an output shaft of a transmission wherein a control unit operatively connected to said serial data bus receives said speed data and calculates said vehicle deceleration values;

and further comprising;

controlling said transmission via said control unit using said sequential vehicle speed data.

14. The method of claim 10, wherein said output signal varies increasingly nonlinearly with increasing vehicle deceleration values.

15. The method of claim 10, wherein said calculating includes subtracting a received vehicle speed datum (V_p) from a consecutive, subsequently-received vehicle speed datum (V_c) and dividing the result (V_c−

V_p) by the elapsed time between receipt of said respective data.

16. The method of claim 10, further comprising:

averaging a number of sequentially-calculated vehicle deceleration values to calculate an average deceleration value;

17. The method of claim 10, further comprising:

calculating the difference between a first calculated vehicle deceleration value and a second calculated deceleration value, said second deceleration value being calculated based on later seqaential speed data than said first deceleration value; and

varying said output signal to correspond with said second deceleration value after a first amount of time K₁ when said second deceleration value is greater than said first deceleration value by a first amount, and after a second amount of time K₂ when said second deceleration value is less than said first deceleration by a second amount, wherein K₁ is different than K₂, such that said output signal varies to correspond with said second deceleration value at a different rate when vehicle deceleration is increasing than when vehicle deceleration is decreasing.

18. The method of claim 10, further comprising:

comparing each of said vehicle deceleration values with a minimum threshold value; and

setting said output signal to zero when said vehicle deceleration value is less than said minimum threshold value.

19. The method of claim 10, further comprising:

recognizing when a vehicle stability event has occurred, said vehicle stability event including at least one of implementation of an anti-lock brake system, implementation of a traction control system, occurrence of an understeer event and occurrence of a rollover event; and

setting said output signal to a preset level when occurrence of a vehicle stability event is recognized.

20. A method comprising:

calculating vehicle deceleration values from sequentially-measured vehicle speed data received via a serial data bus, said vehicle speed data including a plurality of sequentially-measured speeds of an output shaft of a transmission;

providing an output signal that varies in accordance with said calculated vehicle deceleration values;

averaging a number of sequentially-calculated vehicle deceleration values to calculate an average deceleration value defined by the formula;