US5755378A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and system for controlling an automotive HVAC system to prevent formation of cabin thermal stratification
Assignee: Ford Global Technologies LLC
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Filing: 1997-01-21
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Granted: 1998-05-26
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Expires: 2017-01-21
Abstract
Abstract Method and system for modifying the control of an automotive HVAC (heating, ventilation and air conditioning) to prevent the formation of cabin temperature stratification. The control algorithm responds to signals generated by various climate control sensors to calculate a value representing the likelihood of stratification. The stratification strategy achieves the following three functions: (1) calculation of the likelihood of stratification, (2) estimation of probable level of stratification, and (3) modification of strategy to dispel stratification. Fuzzy logic calculations are performed based on fuzzy rules and membership functions to provide these functions and to allow the control to be expressed in simple heuristic terms.
Inventors
- 👤 Gerhard Allan Dage
- 👤 Leighton Ira Davis, Jr.
- 👤 Michael Bradley Bauer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 19:47
CPC Classifications
B; B60; B60H; B60H1/00; B60H1/00642; B60H1/00735; B60H1/00814
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
192 words
A method of determining the occurrence of air stratification in the passenger cabin of a vehicle and automatically overriding an algorithm used in the control of a heating, ventilation and air conditioning (HVAC) system of said vehicle which discharges a flow of air into said passenger cabin, the control system algorithm having a plurality of variables, including cabin temperature, ambient temperature and blower speed, and a plurality of calibration coefficients, and said system includes a variable speed blower, means for varying air temperature of air discharged into the cabin, ducting means for controlling the direction of air flow; actuator means having various control positions for controlling the ratio of fresh air to recirculated air; sensor means for sensing temperature at a predetermined location within the cabin; sensor means for sensing ambient temperature; sensor means for sensing sun load; and means for providing a passenger controlled temperature setting; said method includes the steps of defining a set of membership functions and fuzzy rules between the ambient temperature, cabin temperature and blower speed variables; estimating the probable level of stratification; and modifying the blower speed variable based on the probable level of stratification estimate.
Claim 2
Independent Claim
192 words
A method of determining the occurrence of air stratification in the passenger cabin of a vehicle and automatically overriding an algorithm used in the control of a heating, ventilation and air conditioning (HVAC) system of said vehicle which discharges a flow of air into said passenger cabin, the control system algorithm having a plurality of variables, including cabin temperature, ambient temperature and blower speed, and a plurality of calibration coefficients, and said system includes a variable speed blower, means for varying air temperature of air discharged into the cabin, ducting means for controlling the direction of air flow; actuator means having various control positions for controlling the ratio of fresh air to recirculated air; sensor means for sensing temperature at a predetermined location within the cabin; sensor means for sensing ambient temperature; sensor means for sensing sun load; and means for providing a passenger controlled temperature setting; said method includes the steps of defining a set of membership functions and fuzzy rules between the ambient temperature, cabin temperature and blower speed variables; estimating the probable level of stratification; and modifying the blower speed variable based on the probable level of stratification estimate.
Claim 3
Dependent Claim
21 words
A method as in claim 1, wherein the membership functions are instantiated values of predetermined low, medium-high and high threshold values.
Claim 4
Dependent Claim
25 words
A method as in claim 2, wherein one of the rules determines the likelihood of stratification as being low if the blower speed is high.
Claim 5
Dependent Claim
42 words
A method as in claim 3, wherein a second one of the rules in said set of fuzzy rules determines that the likelihood of stratification occurring is low if the difference between the sensed ambient temperature and sensed cabin temperature is low.
Claim 6
Dependent Claim
50 words
A method as in claim 4, wherein a third one of the rules in said set of fuzzy rules determines that the likelihood of stratification occurring is high if the blower speed is low, difference between the sensed ambient temperature and sensed cabin temperature is high discharge temperature is low.
Claim 7
Dependent Claim
45 words
A method as in claim 5, wherein said system includes a means for sensing sunload and said third one of the rules in said set of fuzzy rules determines that the likelihood of stratification occurring is high if the sunload is also medium-high or above.
Claim 8
Dependent Claim
53 words
A method as in claim 5, wherein said system includes a means for sensing sunload and a fourth one of the rules in said set of fuzzy rules determines that the likelihood of stratification occurring is medium-high if the blower speed is low, the sunload is high and the discharge temperature is low.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2001-05-25 | 2001-11-24 | 2002-05-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-05-25 | 2005-11-24 | 2006-05-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-05-25 | 2009-11-24 | 2010-05-26 | $7700.00 | Window Closed / Lapsed |