Method of measuring a chemical vapor concentration

• US 8,642,345 B2
• Filed: 03/05/2013
• Issued: 02/04/2014
• Est. Priority Date: 01/12/2005
• Status: Active Grant

• Current Assignee: Aptiv Technologies AG (Aptiv PLC)
• Original Assignee: Delphi Technologies, Inc. (BorgWarner Incorporated)
• Inventors: Sultan, Michel F., Lambert, David K.
• Primary Examiner(s): Sines, Brian J
• Application Number:
  US13/785,535
• Publication Number:
  US 20130175108A1
• Time in Patent Office: 336 Days
• Field of Search: 422/50, 422/83, 422/82.01, 436/43, 436/52, 436/181
• US Class Current: 436/43
• CPC Class Codes: B60K 28/06 responsive to incapacity of driver
• CPC Class Codes: B60K 28/063 preventing starting of vehicles
• CPC Class Codes: B60W 2540/24 Drug level, e.g. alcohol
• CPC Class Codes: G01N 21/3504 for analysing gases, e.g. multi-gas analysis
• CPC Class Codes: G01N 21/61 Non-dispersive gas analysers G01N21/3504 takes precedence
• CPC Class Codes: G01N 33/4972 Determining alcohol content for vehicle safety devices B60K28/06
• CPC Class Codes: Y10T 436/11 Automated chemical analysis
• CPC Class Codes: Y10T 436/117497 with a continuously flowing sample or carrier stream
• CPC Class Codes: Y10T 436/25 including sample preparation
• CPC Class Codes: Y10T 436/255 including use of a solid sorbent, semipermeable membrane, or liquid extraction
• CPC Class Codes: Y10T 436/25875 Gaseous sample or with change of physical state

Abstract

A method of measuring a chemical vapor concentration is provided. A chemical vapor sensor measures a chemical species of interest with high sensitivity and chemical specificity. In an aspect, an ethanol vapor sensor is provided, sized for being inconspicuous and on-board a vehicle, having a passive measurement mode and an active breathalyzer mode, for detecting a motor vehicle driver that exceeds a legal limit of blood alcohol concentration (BAC), for use with vehicle safety systems. For the passive mode, a vapor concentrator is utilized to amplify a sampled vapor concentration to a detectable level for use with an infrared (IR) detector. In an aspect, ethanol vapor in a vehicle cabin is passively measured and if a predetermined ethanol level is measured, a countermeasure is invoked to improve safety. In an aspect, an active breathalyzer is used as a countermeasure. The active breathalyzer can be imposed for a number of vehicle trips or for a predetermined time period.

Claims

1. A method of measuring a chemical vapor concentration comprising:

providing a chemical vapor passive sensor that includes an infrared source and an infrared detector configured to detect infrared light in an infrared absorption cell;

passing air, including sample vapor, through an adsorber;

measuring a first output (designated Voff) of an infrared detector, with the infrared source deactivated;

heating the adsorber;

measuring a second output (designated Von) of the infrared detector, with the infrared source activated;

passing concentrated sample vapor from the adsorber into and through the infrared absorption cell;

measuring a change in an third output (designated Vsig) of the infrared detector;

calculating a ratio Vsig/(Von−

Voff); and

measuring the chemical vapor concentration based on the ratio.

2. The method of measuring a chemical vapor concentration as in claim 1, wherein passing concentrated sample vapor from the adsorber into and through the infrared absorption cell comprises:

activating air flow just long enough to transfer concentrated sample vapor from the adsorber into the infrared absorption cell;

holding the concentrated sample vapor in the infrared absorption cell for a predetermined and desired time; and

activating air flow again to purge the adsorber and the infrared absorption cell of the concentrated sample vapor.

3. The method of measuring a chemical vapor concentration as in claim 1, wherein passing air, including the sample vapor, through the adsorber comprises passing vehicle cabin air through the adsorber, and wherein the sample vapor is ethanol vapor.

4. The method of measuring a chemical vapor concentration as in claim 1, wherein a microcontroller calculates the ratio Vsig/(Von−

Voff), and instructs and carries out a safety response.

5. The method of measuring a chemical vapor concentration as in claim 1, wherein the method further includes the steps of:

providing a chemical vapor active sensor;

passing unmixed gas into the infrared absorption cell; and

measuring an unmixed gas infrared absorption within the infrared absorption cell with the infrared source activated, utilizing the infrared detector.

6. The method of measuring a chemical vapor concentration as in claim 5, wherein passing unmixed gas comprises passing human breath, wherein measuring the unmixed gas infrared absorption comprises measuring ethanol infrared absorption, and wherein a first predetermined concentration is less than 210 parts per million (ppm).

7. The method of measuring a chemical vapor concentration as in claim 6, further comprising imposing a safety response when the chemical vapor active sensor detects that the sample vapor exceeds the first predetermined concentration, wherein the safety response includes at least one of setting a flag counter which requires an active breathalyzer test (utilizing the chemical vapor active sensor) for at least one of a predetermined number of vehicle trips and a predetermined time to prevent a vehicle engine from restarting until a driver'"'"'s BAC is measured as a level established as legal to operate a motor vehicle.

8. The method of measuring a chemical vapor concentration as in claim 5, further including the steps of:

utilizing the chemical vapor passive sensor when one of;

a flag is set to a pass setting, and a chemical vapor active sensor detects that a first chemical vapor concentration is below a first predetermined concentration;

utilizing the chemical vapor active sensor when the flag is set to a second setting;

setting the flag to the first setting when the chemical vapor passive sensor is utilized and detects that a second chemical vapor concentration is within a second predetermined concentration range; and

setting the flag to the second setting when the chemical vapor passive sensor is utilized and detects that the second chemical vapor concentration exceeds the second predetermined concentration range.

9. The method of measuring a chemical vapor concentration as in claim 8, further comprising imposing a safety response when the chemical vapor passive sensor detects that the sample vapor indicates that a vehicle occupant exceeds a legal blood alcohol concentration (BAC) for a driver, wherein the safety response includes at least one of setting the flag to the second setting, setting a flag counter which requires an active breathalyzer test, utilizing the chemical vapor active sensor, for at least one of a predetermined number of vehicle trips and a predetermined time to prevent a vehicle engine from restarting until a driver'"'"'s BAC is measured as a level established as legal to operate a motor vehicle, warning passengers to fasten seat belts, increasing a minimum headway distance behind a preceding vehicle, constraining vehicle performance, transmitting vehicle cabin ethanol measurements to police and to a vehicle recorder.

10. The method of measuring a chemical vapor concentration as in claim 8, further comprising at least one of utilizing the chemical vapor active sensor when the flag is set to first, and utilizing the chemical vapor passive sensor when the flag is set to second.

11. The method of measuring a chemical vapor concentration as in claim 10, wherein the first setting is the pass setting and the second setting is a fail setting.