Programmable automotive computer system having start time and wheel spin correction

• US 7,647,138 B2
• Filed: 11/01/2005
• Issued: 01/12/2010
• Est. Priority Date: 11/01/2004
• Status: Active Grant

• Current Assignee: Hypertech, Inc.
• Original Assignee: Hypertech, Inc.
• Inventors: Heffington, Mark F.
• Primary Examiner(s): PIPALA, EDWARD J
• Application Number:
  US11/265,707
• Publication Number:
  US 20070078571A1
• Time in Patent Office: 1,533 Days
• Field of Search: 180/197, 701/1, 701/29, 701/33, 701/35, 702/1, 702/85, 702/86, 702/89, 702/96, 702/141, 702/142, 702/148, 73/10.1, 73/2, 73/17.9, 734/88, 734/89, 734/90, 735/03, 324/160, 324/162, 324/163
• US Class Current: 701/1
• CPC Class Codes: B60R 16/0231 Circuits relating to the driving or the functioning of the vehicle monitoring tyres B60C23/00; indicating overspeed B60K31/00; for dash boards B60K37/00, B60Q3/10; for indicating emergencies B60Q1/52; brake control systems B60T; registering or indicating the working of vehicles G07C5/00; measuring distance G01C, e.g. combinations of speed and distance G01C23/00; engine indicators G01L; measuring speed or acceleration G01P
• CPC Class Codes: B60R 16/0232 for measuring vehicle parameters and indicating critical, abnormal or dangerous conditions
• CPC Class Codes: G07C 5/008 communicating information to a remotely located station transmission systems for measured values G08C
• CPC Class Codes: G07C 5/085 using electronic data carriers

Abstract

A system, device, and corresponding method for enabling a user to accurately control, monitor, and evaluate performance of a vehicle. A portable programmable computer device that a user can readily install by plugging it into a diagnostic connector port of the vehicle. The system includes a detector for detecting the start time of first movement of the vehicle independent of the on board diagnostic system. Velocity data from the onboard diagnostic system is time stamped by a clock in the device and stored. Velocity curves are generated from the velocity data and time stamps. Wheel spin is accounted for by smoothing the velocity curve to determine a point of inflection in the velocity indicative of termination of wheel spin and creating correcting velocity and acceleration curves by solving equations from the inflection point backwards on the curve down to time zero. From the corrected curves, an accurate distance is calculated.

Claims

1. A method for determining the time it takes for a vehicle to travel from a standing start to a selected distance, wherein said method corrects for errors in the velocity values generated by the vehicle'"'"'s onboard diagnostics system, comprising the steps of:

detecting the start time of vehicle travel independent of the onboard diagnostics system;

storing the velocity values received from the onboard diagnostics system;

determining and storing for each velocity value the time period from the start time to when each velocity value is received;

generating a velocity curve from said velocity values; and

integrating the velocity values to calculate the time of travel from the start time to the selected distance.

2. The method of claim 1, wherein the errors in the velocity values include errors resulting from vehicle wheel spin, and wherein the step of generating a velocity curve comprises the steps of:

determining the time that an inflection point occurs in the velocity values output by the onboard diagnostics system indicative of the end of the wheel spin state;

interpolating the velocity and acceleration values from the inflection point back in time to the start time.

3. The method of claim 1, where the start time is detected as a function of detection of the first movement of the vehicle as part of a test run.

4. The method of claim 1, wherein the start time is detected using an accelerometer.

5. The method of claim 1, wherein the start time is detected using a mercury switch.

6. The method of claim 1, wherein the start time is detected as a function of detection of movement of an accelerator pedal of the vehicle.

7. The method of claim 1, wherein the start time is detected as a function of detection of movement of a brake pedal of the vehicle.

8. The method of claim 1, wherein the vehicle has a manual transmission and the start time is detected as a function of clutch release.

9. The method of claim 1, further comprising the step of calculating and displaying the times to reach one or more predetermined speeds as a function of at least one of the calculated distances, velocity curve values, and acceleration curve values.

10. The method of claim 1, further comprising the step of calculating and displaying the times to reach one or more predetermined distances as a function of at least one of the calculated distances, velocity curve values, and acceleration curve values.

11. The method of claim 1, further comprising the step of calculating and displaying engine horsepower as a function of at least one of the calculated distances, velocity curve values, and acceleration curve values.

12. The method of claim 1, further comprising the step of calculating and displaying engine torque as a function of at least one of the calculated distances, velocity curve values, and acceleration curve values.

13. A method for calculating distances traveled associated with driving a vehicle in a test run from a standing start over a selected distance, wherein said method corrects for velocity errors in the data obtained from the onboard diagnostics system (OBD) arising from wheel spin, including the steps of:

detecting the start time of first movement of vehicle in test run;

reading velocity values from the OBD;

time stamping said velocity values using a clock,

generating a velocity curve from said velocity values and time stamps;

smoothing said velocity curve so as to determine a point of inflection in the velocity indicative of a termination of wheel spin;

determining elapsed time from the start time to the inflection point; and

interpolating the velocity values to determine the correct distance from the start time to the inflection point.

14. A method for determining the time it takes for a vehicle to travel from a standing start to a selected distance, wherein the determination corrects for errors in the velocity values generated by the vehicle'"'"'s onboard diagnostics system, wherein the errors in the velocity values include errors arising from wheel spin, comprising the steps of:

detecting the start time of vehicle travel independent of the onboard diagnostics system;

time stamping each of the velocity values generated by the vehicle'"'"'s onboard diagnostics system;

determine an inflection point in the velocity values output by the onboard diagnostics system indicative of the end of the wheel spin state;

determining the time that the inflection point occurs based on the time stamp of the velocity value at the inflection point;

generating a velocity curve from the velocity values from the inflection point forward in time;

integrating the velocity values of the generated velocity curve from the inflection point forward in time to calculate the corrected distance from the inflection point forward;

interpolating the velocity values from the start time to the inflection point such that the interpolated velocity curve connects to the generated velocity curve at the inflection point; and

integrating the velocity values of the interpolated velocity curve to calculate the corrected distance from the start time to the inflection point.

15. The method of claim 14, wherein the corrected velocity curve is a straight line from the start time to connect to the generated velocity curve at the inflection point.

16. The method of claim 14, wherein the corrected velocity curve is based on a velocity polynomial equation having coefficients solved based on the value of the generated velocity curve and calculated acceleration at the inflection point along with an initial value of zero for the polynomial equation at the start time, wherein the solved coefficients are inserted into the velocity polynomial equation.

17. The method of claim 16, wherein the corrected distance is determined from integration of the velocity polynomial equation that includes the solved coefficients.

18. The method of claim 16, wherein the corrected distance is determined from a polynomial equation for distance that includes the solved coefficients.

19. An electronic portable device for determining the time it takes for a vehicle to travel from a standing start to a selected distance, wherein the device corrects for errors in the velocity values generated by the vehicle'"'"'s onboard diagnostics system, comprising:

an input/output port for coupling said device to said diagnostic port for accessing the onboard diagnostic system and the engine computer;

a detector for detecting the start time of vehicle travel independent of the onboard diagnostics system;

a microcontroller operative for determining for each velocity value the time period from the start time to when each velocity value is received, for generating a velocity curve from said velocity values; and

for integrating the velocity values to calculate the time of travel from the start time to the selected distance;

a memory for providing storage in said device for velocity values received from the onboard diagnostics system and providing storage in said device, for each velocity value, the time period from the start time to when each velocity value is received; and

a touch screen display for enabling user control of device operations.