Method of establishing baseline filter for air quality

• US 6,298,291 B1
• Filed: 12/22/1999
• Issued: 10/02/2001
• Est. Priority Date: 12/22/1999
• Status: Expired due to Term

• Current Assignee: Visteon Global Technologies Incorporated (Visteon Corporation)
• Original Assignee: Visteon Global Technologies Incorporated (Visteon Corporation)
• Inventors: Dage, Gerhard Allen, Hoeschele, John David, Davis, Leighton Ira Jr.
• Primary Examiner(s): Camby, Richard M.
• Application Number:
  US09/470,632
• Time in Patent Office: 650 Days
• Field of Search: 701/36, 180/68.2, 454/69, 454/75, 454/74, 454/71, 454/156, 454/158, 552/83
• US Class Current: 701/36
• CPC Class Codes: B60H 1/008 the input being air quality
• CPC Class Codes: B60H 1/00849 for selectively commanding the induction of outside or inside air B60H1/00842 takes precedence
• CPC Class Codes: B60H 3/0085 Smell or pollution preventing arrangements B60H3/0007, B60H3/0071, B60H3/02, B60H3/06 take precedence

Abstract

A method of establishing a baseline filter for an air quality sensor in a motor vehicle includes the step of providing an air quality sensor for intake air into an occupant compartment of the motor vehicle. The method also includes the step of establishing a moving baseline for a background signal level from the air quality sensor. The method further includes the step of shutting off intake air into an occupant compartment of the motor vehicle when the background signal level exceeds a certain threshold above the moving baseline, thereby preventing undesired gases in the intake air from reaching occupants in the occupant compartment.

Claims

1. A method of establishing a baseline filter for an air quality sensor in a motor vehicle, said method comprising the steps of:

providing an air quality sensor for intake air into an occupant compartment of the motor vehicle;

establishing a moving baseline for a background signal level from the air quality sensor; and

shutting off intake air into an occupant compartment of the motor vehicle when the background signal level exceeds a certain threshold above the moving baseline, thereby preventing undesired gases in the intake air from reaching occupants in the occupant compartment.

2. A method of establishing a baseline filter for an air quality sensor in a motor vehicle, said method comprising the steps of:

providing an air quality sensor for intake air into an occupant compartment of the motor vehicle;

establishing a moving baseline for a background signal level from the air quality sensor; and

shutting off intake air into an occupant compartment of the motor vehicle when the background signal level exceeds a certain threshold above the moving baseline, thereby preventing undesired gases in the intake air from reaching occupants in the occupant compartment; and

wherein said step of establishing comprises calculating the moving baseline according to the equation y_k+1=(1−

β

)y_k+β

u′

_k.

3. A method of establishing a baseline filter for an air quality sensor in a motor vehicle, said method comprising the steps of:

providing an air quality sensor for intake air into an occupant compartment of the motor vehicle;

establishing a moving baseline for a background signal level from the air quality sensor; and

shutting off intake air into an occupant compartment of the motor vehicle when the background signal level exceeds a certain threshold above the moving baseline, thereby preventing undesired gases in the intake air from reaching occupants in the occupant compartment; and

initializing time t equal to zero.

4. A method of establishing a baseline filter for an air quality sensor in a motor vehicle, said method comprising the steps of:

providing an air quality sensor for intake air into an occupant compartment of the motor vehicle;

establishing a moving baseline for a background signal level from the air quality sensor; and

shutting off intake air into an occupant compartment of the motor vehicle when the background signal level exceeds a certain threshold above the moving baseline, thereby preventing undesired gases in the intake air from reaching occupants in the occupant compartment; and

calculating an intermediate signal level according to the equation z_k+1=(1−

β

)z_k+β

u_k.

5. A method as set forth in claim 4 including the step of determining whether a sample of the signal from the air quality sensor, u_k, is less than or equal to the moving baseline, y_k, plus a threshold, θ

.

6. A method as set forth in claim 5 including the step of setting time t equal to zero if the sample of the signal from the air quality sensor is less than or equal to the moving baseline plus the threshold.

7. A method as set forth in claim 6 including the step of setting u′

_k equal to u_k.

8. A method as set forth in claim 6 including the step of calculating the moving baseline according to the equation y_k+1=(1−

β

)y_k+β

u′

_k.

9. A method as set forth in claim 4 including the step of setting time t equal to t+1 if the sensed sample of air is not less than or equal to the moving baseline plus the threshold.

10. A method as set forth in claim 9 including the step of determining whether the time t is less than or equal to a hold-off time, t_holdoff.

11. A method as set forth in claim 10 including the step of setting u′

_k equal to y_k if the time t is less than or equal to t_holdoff.

12. A method as set forth in claim 11 including the step of calculating the final moving baseline according to the equation y_k+1=(1−

β

)y_k+β

u′

_k.

13. A method as set forth in claim 10 including the step of setting u′

_k equal to z_k+1 if the time t is not less than or equal to t_holdoff.

14. A method as set forth in claim 13 including the step of calculating the final moving baseline according to the equation y_k+1=(1−

β

)y_k+β

u′

_k.

15. A method of establishing a baseline filter for an air quality sensor in a motor vehicle, said method comprising the steps of:

providing an air quality sensor for intake air into an occupant compartment of the motor vehicle;

establishing a moving baseline for a background signal level from the air quality sensor by calculating an intermediate signal level according to the equation z_k+1=(1−

β

)z_k+β

u_k and calculating the moving baseline according to the equation y_k+1=(1−

β

)y_k+β

u′

_k; and

shutting off intake air into an occupant compartment of the motor vehicle when the background signal level exceeds a certain threshold above the moving baseline, thereby preventing undesired gases in the intake air from reaching occupants in the occupant compartment.

16. A method of establishing a baseline filter for an air quality sensor in a motor vehicle, said method comprising the steps of:

providing an air quality sensor for intake air into an occupant compartment of the motor vehicle;

establishing a moving baseline for a background signal level from the air quality sensor by calculating an intermediate signal level according to the equation z_k+1=(1−

β

)z_k+β

u_k and calculating the moving baseline according to the equation y_k+1=(1−

β

)y_k+β

u′

_k; and

shutting off intake air into an occupant compartment of the motor vehicle when the background signal level exceeds a certain threshold above the moving baseline, thereby preventing undesired gases in the intake air from reaching occupants in the occupant compartment; and

determining whether a sensed sample of air, u_k, is less than or equal to the moving baseline, y_k, plus a threshold, θ

.

17. A method as set forth in claim 16 including the step of setting time t equal to zero if the sensed sample of air is less than or equal to the moving baseline plus the threshold.

18. A method as set forth in claim 17 including the step of setting u′

k equal to uk.

19. A method as set forth in claim 16 including the step of setting time t equal to t+1 if the sensed sample of air is not less than or equal to the moving baseline plus the threshold.

20. A method as set forth in claim 19 including the step of determining whether the time t is less than or equal to a hold-off time, t_holdoff, setting u′

_k equal to y_k if the time t is less than or equal to t_holdoff, and setting u′

_k equal to z_k+1 if the time t is not less than or equal to t_holdoff.