Abstract:
A climate control system and method for preventing exhaust odors from entering the passenger compartment of a motor vehicle. The climate control system includes a duct network and a damper system that is moveable between a fresh air mode and a recirculation air mode. The damper system being moved based at least in part upon a vehicle acceleration condition. During operation, the system is operated in the recirculation air mode during acceleration in a situation that probably has a high concentration of the exhaust odor and gases. The system operates in the fresh air mode when the situation is one that does not have a high probability of a high concentration of exhaust odors and gases.

Description:
BACKGROUND 
       [0001]    1. Field of Invention 
         [0002]    The present invention relates generally to climate control systems and, more particularly, to an automotive climate control system which prevents exhaust odors from entering the passenger compartment of a vehicle. 
         [0003]    2. Related Technology 
         [0004]    Climate control systems in automotive vehicles serve many important functions. One function is to provide comfortable conditions for occupants within the vehicle. In operation, automotive climate control systems circulate outside air to vehicle passengers. This air may contain unpleasant engine exhaust odors from other surrounding vehicles. 
         [0005]    Current climate control systems may use an odor detection sensor to prevent unpleasant exhaust odors from entering the passenger compartment of the vehicle. If unacceptable outside air exists, based on odor detection, the climate control system rejects outside air and re-circulates the interior air. When the unpleasant exhaust odor condition is passed, the air mode is reset to accept fresh outside air for passengers. This method, however, bears the cost of the odor detection sensor. 
         [0006]    Alternatively, climate control systems may use a contaminant sensor coupled with a filtration system. Upon indication of contaminants entering the air flow into a vehicle interior, the climate control system causes the air flow to pass through a filter or a decontamination module to clean the air. The decontaminated air is then supplied to the vehicle interior. Once the conditions have improved, the climate control system detects the satisfactory conditions and the air is no longer caused to pass through the decontamination module. This method, however, bears the high cost of the contaminant sensor and filtration system. 
         [0007]    Thus, a need exists for an efficient and cost effective climate control system and method for preventing unpleasant odors, such as exhaust odors, from entering the passenger compartment of a vehicle. 
       SUMMARY 
       [0008]    In satisfying the above need, as well as overcoming the enumerated drawbacks and other limitations of the related art, the present invention provides an automotive climate control system that optimizes occupant comfort by preventing unpleasant odors, such as exhaust odors, from entering the vehicle passenger compartment while minimizing system costs. 
         [0009]    The invention is based on the understanding that concentrations of exhaust odors surrounding a vehicle are highest in places where vehicles accelerate. During acceleration, exhaust gas flow can be an order of magnitude greater than cruising, and two orders of magnitude greater than idling. When an accelerating automobile follows other accelerating automobiles, it is exposed to high concentrations of exhaust. Acceleration in these instances is most likely to occur when vehicles pull away from intersections. Exhaust concentration is further increased at intersections because accelerating vehicles are initially slow moving with large exhaust flows. Additionally, there can be multiple, closely spaced, forwardly located vehicles simultaneously accelerating on a new green traffic light. The combination of these common factors is the worst case scenario for exhaust concentrations in outside air. Therefore, to prevent unpleasant exhaust odors from entering the passenger compartment of a vehicle, the mode of operation of the climate control system of the present invention is dependent upon vehicle acceleration, when exhaust odor from traffic is most likely. 
         [0010]    The automotive climate control system includes a duct network, which may house an evaporator, a heater, and a blower. The duct network includes a fresh air intake located so as to intake outside air, an interior air intake located so as to intake recirculation air, and an air outtake for supplying air to the passenger compartment. The blower causes the air from the fresh air intake and/or the interior air intake to move across the evaporator and heater, through the air outtake, and into the passenger compartment. The climate control system further includes an electronic climate control module (ECCM) and a damper door configured to selectively operate the system in fresh air mode (where the damper door closes the interior air intake permitting air passage through the fresh air intake) or recirculation air mode (where the damper door closes the fresh air intake permitting air passage through the interior air intake). 
         [0011]    Further, the ECCM is configured to determine vehicle acceleration based at least in part on a signal from a vehicle speed determining system. The vehicle speed determining system may include a speed sensor, an accelerometer, a vehicle navigation system, a global positioning sensor system or any suitable means for obtaining speed information from a vehicle network. Upon the detection of vehicle acceleration and other acceptable climate control system conditions permitting re-circulated air to enter the passenger compartment of the vehicle, the ECCM will operate the climate control system in recirculation air mode, thereby rejecting outside air likely to be contaminated with unpleasant exhaust odors. The ECCM will switch the mode of operation to fresh air mode after acceleration reaches a low threshold and a dwell time has passed, thus permitting outside air to enter the passenger compartment of a vehicle. This occurs when the vehicle is likely to be surrounded by a low concentration of exhaust odors. 
         [0012]    One advantage of the present invention is the cost-effective ability to optimize passenger comfort. The system improves the quality of air inside a vehicle using speed data from a vehicle speed determining system and an ECCM. Interior air is re-circulated based on a vehicle acceleration condition, thus eliminating the costs of an odor detection sensor and/or a special filtration system. 
         [0013]    In at least one embodiment, the automotive climate control system comprises a duct network including a fresh air intake (that receives air from outside the vehicle), an interior air intake (that receives air from the passenger compartment of the vehicle), and an air outtake (that provides air to the passenger compartment of the vehicle). The duct network further includes a damper system that is moveable between a fresh air mode and a recirculation air mode. In the fresh air mode, the damper system generally prevents the passage of air into the duct network from the interior air intake. In the recirculation air mode, the damper system generally prevents the passage of air into the duct network from the fresh air intake. 
         [0014]    A controller is coupled to the damper and configured to cause movement of the damper system between the fresh air mode and the recirculation air mode. The controller is configured to operate the climate control system in the fresh air mode upon the detection of a first condition that is based at least in part upon a vehicle acceleration condition. The controller is configured to operate the climate control system in the recirculation air mode upon the detection of a second condition that is based at least in part upon a vehicle acceleration condition. 
         [0015]    In another embodiment, the controller is configured to determine vehicle acceleration based at least in part on a signal from a vehicle speed determining system. The vehicle speed determining system may include a speed sensor, an accelerometer, a vehicle navigation system, or a global positioning sensor system. 
         [0016]    In another embodiment, the controller is configured to operate the climate control system in the fresh air mode upon the detection of a first condition that is based at least in part upon a vehicle acceleration condition, where the vehicle acceleration condition is acceleration below a threshold limit or no acceleration. 
         [0017]    In another embodiment, the controller is configured to operate the climate control system in the fresh air mode upon the detection of a first condition that is based at least in part upon a time condition, where the time condition is expiration of a timer. 
         [0018]    In another embodiment, the controller is configured to operate the climate control system in the fresh air mode upon the detection of a first condition that is based at least in part upon a vehicle acceleration condition and at least in part upon a time condition, where the vehicle acceleration condition is acceleration below a threshold limit and the time condition is the expiration of a timer. 
         [0019]    In another embodiment, the controller is configured to operate the climate control system in the recirculation air mode upon the detection of a second condition that is based at least in part upon a vehicle acceleration condition, where the vehicle acceleration condition is the existence of acceleration or acceleration above a threshold limit. 
         [0020]    In another aspect, the present invention provides a method of operating a climate control system to prevent exhaust odor from entering the passenger compartment of the vehicle. The climate control system includes a fresh air intake, an interior air intake, and an air outtake, a damper system and a controller. The method of the present invention includes determining vehicle acceleration. The method further includes detecting a first condition based at least in part upon a vehicle acceleration condition. Upon detecting the first condition, the climate control system operates in a fresh air mode to accept outside air through the fresh air intake and provide the outside air to the passenger compartment of the vehicle. 
         [0021]    The method further includes detecting a second condition based at least in part upon a vehicle acceleration condition. Upon detecting the second condition, the climate control system operates in a recirculation air mode to accept recirculation air from the interior air intake and provide the recirculation air to the passenger compartment of the vehicle. 
         [0022]    In another aspect, the method of operating a climate control system for a vehicle includes detecting a first condition based at least in part on a vehicle acceleration condition, where the step of detecting the first condition includes determining if acceleration is below of threshold limit or if no acceleration exists. The step of detecting the first condition may also be based at least in part on a time condition. 
         [0023]    In another aspect, the method of operating a climate control system for a vehicle includes detecting a first condition based at least in part upon a vehicle acceleration condition and at least in part upon a time condition, where the step of detecting the first condition includes determining if the vehicle acceleration is below a threshold limit and if a timer has expired. 
         [0024]    In another aspect, the method of operating a climate control system for a vehicle includes detecting a second condition based at least in part on a vehicle acceleration condition, where the step of detecting the second condition includes determining if acceleration exists or if acceleration exists above a threshold limit. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0025]      FIG. 1  is a schematic illustration of a vehicle climate control system embodying the principles of the present invention; and 
           [0026]      FIG. 2  is a flow chart depicting operation of the system according to the present invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0027]    The following description of the preferred embodiment of the invention is not intended to limit the scope of the invention to this preferred embodiment, but rather to enable any person skilled in the art to make and use the invention. 
         [0028]    Referring now to  FIG. 1 , illustrated therein is a portion of a vehicle climate control system  10  for providing fresh or recirculation air so as to minimize exhaust odors in the passenger compartment of the vehicle at various driving situations. The climate control system  10  includes a housing or duct network  12 , which surrounds one or more of an evaporator  14 , a heater  16 , and a blower  18 , the latter of which may comprise a fan  20  and a motor  22  to blow air across the evaporator  14  and heater  16 . The duct network  12  is provided with a fresh air intake  24  for outside air, an interior air intake  26  for recirculation air, and an air outtake  28  for supplying air to the passenger compartment of the vehicle. 
         [0029]    The climate control system  10  further includes a programmable electronic climate control module (ECCM)  30  configured to selectively operate the climate control system  10  in fresh air mode  32  or recirculation air mode  34 . 
         [0030]    During operation in fresh air mode  32 , the interior air intake  26  is closed off and the fresh air intake  24  is open so that the air supplied to the passenger compartment via the air outtake  28  is fresh air from the fresh air intake  24 . Conversely, during operation in recirculation air mode  34 , the fresh air intake  24  is closed off and the interior air intake  26  is open such that outside air is rejected and interior air is re-circulated to the passenger compartment through the air outtake  28 . 
         [0031]    To control whether the climate control system  10  operates in fresh air mode  32  or recirculation air mode  34 , the ECCM  30  is configured to actuate a damper door  36  to close off the interior air intake  26  or the fresh air intake  24 , respectively, during various driving situations. 
         [0032]      FIG. 1  shows a first operating condition set by the ECCM  30  through its actuation of the damper door  36 . This operation condition is characterized by operation in the fresh air mode  32 , wherein the pivotally mounted damper door  36  is positioned to prevent air passage through the interior air intake  26  and to permit air passage through the fresh air intake  24  when the driving condition so demands. 
         [0033]      FIG. 1  further illustrates (in phantom) a second operating condition characterized by operation in the recirculation air mode  34 , wherein the pivotally mounted damper door  36  is positioned to prevent air passage through the fresh air intake  24  and permit air passage through the interior air intake  26 . Operating the climate control system  10  in recirculation air mode  34  is particularly useful when, for example, a vehicle is accelerating out of an intersection. As noted above, this situation is when the outside concentration of exhaust gas from surrounding vehicles is typically greatest. 
         [0034]    In order to detect such a driving condition, the ECCM  30  receives vehicle speed data from a vehicle speed sensor  38 . Based in part on the output of the vehicle speed sensor  38 , the ECCM  30  determines if the vehicle is potentially in a situation where the concentration of exhaust gas in the air surrounding the vehicle is at an unacceptable level or if the vehicle is most likely in a situation where the concentration of exhaust gas in the air surrounding the vehicle is at an acceptable level. 
         [0035]      FIG. 2  depicts a flow diagram representative of program instructions executed by the ECCM  30  for carrying out the above-described control in the context of a system in which the operating air mode is varied between the fresh air mode  32  and the recirculation air mode  34 , based on vehicle acceleration. This process is repeatedly executed while the climate control system  10  is being operated. 
         [0036]    The method starts at STEP  49  and proceeds to determine vehicle acceleration, as indicated at STEP  50 . The acceleration is based at least in part on speed data from a vehicle speed determining system. For example, a vehicle speed sensor, an accelerometer, a vehicle navigation system, or a global positioning sensor system may provide vehicle speed information to the ECCM  30  so that the ECCM  30  can determine if the vehicle is accelerating above a threshold limit. When the ECCM  30  determines that the vehicle is accelerating below a threshold limit, and thus probably not in the presence of high concentrations of outside exhaust odors, it sends a signal to run a timer  40 , as indicated at STEP  52 . At STEP  54 , the ECCM  30  determines whether the timer  40  has expired. If the timer  40  has not expired, the process returns to STEP  49  and re-checks the vehicle acceleration. If the vehicle acceleration condition is still below a threshold limit, the timer  40  continues to run, as indicated at STEP  52 . Alternatively, if the ECCM  30  determines that the timer  40  has expired, the ECCM  30  next determines whether the fresh air mode is allowed at STEP  56 . Subject to other acceptable climate control system conditions permitting outside air to enter the passenger compartment of the vehicle as determined in STEP  56 , the ECCM  30  will either return to STEP  49  (if the answer is “No”) or set the climate control system  10  to fresh air mode  32  (if the answer is “Yes”) as indicated at STEP  58 . Thereafter the method returns to start (STEP  49 ) and the method begins again. Therefore, provided that the vehicle acceleration is below a threshold limit and a dwell time has passed and hence the vehicle is likely to be surrounded by a low concentration of exhaust doors, and if other acceptable climate control system conditions allow fresh air to enter the vehicle, the ECCM  30  will operate the climate control system  10  in fresh air mode  32  and permit the passage of fresh outside air into the passenger compartment of the vehicle. 
         [0037]    Conversely, if STEP  50  reveals that the vehicle is accelerating above a threshold limit, and thus likely surrounded by a high concentration of exhaust odors, the ECCM  30  will move to STEP  60  to determine whether the recirculation air mode  34  is allowed. If other acceptable climate control system conditions do not permit the system  10  to enter the recirculation air mode  34 , then the method returns to start (STEP  49 ) and begins again. If the other climate control system conditions do permit re-circulated air to enter the passenger compartment of the vehicle, then the ECCM  30  will set the climate control system  10  to recirculation air mode  34  and set a timer  40 , as indicated by STEP  62 . Thereafter the method returns to start (STEP  49 ) and the method begins again. As long as acceleration remains above a threshold value (based on design criteria of the system), the system  10  will remain in the recirculation air mode  34 . Therefore, provided that the vehicle is accelerating above a threshold limit and thus likely to be surrounded by a high concentration of exhaust odors, if other acceptable climate control system conditions allow recirculation air to enter the passenger compartment of the vehicle, the ECCM  30  will operate the climate control system  10  in recirculation air mode  34  and re-circulate the interior air to the passenger compartment. 
         [0038]    Thus, the ECCM  30  adjusts the air mode of operation of the climate control system  10  between fresh air mode  32  and recirculation air mode  34 , to improve air quality for vehicle passengers, by rejecting outside air and re-circulating interior air during vehicle acceleration when the anticipated concentration of surrounding exhaust odors is highest. This control, based on vehicle acceleration, thereby provides both an effective and cost efficient climate control system  10 . 
         [0039]    Alternative embodiments other than those described above may be used with the present invention. It is therefore intended that the foregoing detailed description be regarded as illustrative rather than limiting, and that it be understood that it is the following claims, including all equivalents, that are intended to define the spirit and scope of this invention.