Abstract:
An air conditioning system providing cooled air to a vehicle includes a detection device, a control module, and an air adjusting module. The detection device determines whether another vehicle is in front of the vehicle within a predetermined distance, and sends a signal when the other vehicle is detected. The control module is coupled to the detection device and controls the air adjusting module to operate in a recirculation mode upon receiving the signal.

Description:
BACKGROUND 
       [0001]    1. Technical Field 
         [0002]    The present disclosure relates to air conditioning systems, and particularly to an air conditioning system used in a vehicle. 
         [0003]    2. Description of related art 
         [0004]    Air conditioning systems (A/C systems) are well known in the art, operating on the principle of evaporation and condensation to provide cooled air in indoor areas, including vehicle interiors. 
         [0005]    Often, vehicle A/C systems can be manually switched between a ventilation mode, in which an inside air inlet is closed and an outside air inlet opened, drawing fresh air into the interior of the vehicle, and recirculation mode, in which the inside air inlet is opened and the outside inlet closed, recirculating air within the interior of the vehicle. 
         [0006]    However, in city driving, exterior air quality is often poor, especially in conditions of heavy traffic. If ventilation mode is utilized, air introduced to the vehicle interior can easily contain numerous contaminants such as vehicle exhaust emissions. While the emissions can be routed through a filtering system, net effect is often less than ideal, resulting in an unpleasant environment being created inside the vehicle. 
         [0007]    Thus, an air conditioning system providing reliable exclusion of exhaust emission from other vehicles or the user&#39;s vehicle, a method of operating the system, and a vehicle using the air conditioning system, are desired. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]      FIG. 1  is a schematic view of two vehicles with air conditioning systems in accordance with an exemplary embodiment. 
           [0009]      FIG. 2  is a block diagram of the two vehicles with air conditioning systems of  FIG. 1 . 
           [0010]      FIG. 3  is a detailed block diagram of the air conditioning system of  FIG. 1  in accordance with a first embodiment. 
           [0011]      FIG. 4  is a detailed block diagram of the air conditioning system of  FIG. 1  in accordance with a second embodiment. 
           [0012]      FIG. 5  is a flowchart of a method implemented by the air conditioning system for preventing intake of emissions in accordance with a first embodiment. 
           [0013]      FIG. 6  is a flowchart illustrating a method implemented by the air conditioning system for preventing intake of emissions in accordance with a second embodiment. 
       
    
    
     DETAILED DESCRIPTION 
       [0014]    Referring to  FIG. 1  and  FIG. 2 , a first vehicle  20  and a second vehicle  30  are illustrated. The first vehicle  20  includes a detection device  22  and an air conditioning system  24 . The detection device  22  is located in a front end of the first vehicle  20 , and determines whether another vehicle, such as the second vehicle  30 , is within a predetermined distance of the first vehicle  20 . The detection device  22  may be an ultrasonic transducer or a video camera. The predetermined distance is preset to, for example, two or three meters (m), and is fully adjustable according to preference. When the second vehicle  30  is determined to be within the predetermined distance, the detection device  22  alerts the air conditioning system  24  by transmission of a signal thereto. 
         [0015]    The air conditioning system  24  is installed in the first vehicle  20 , electrically coupled to the detection device  22 . The air conditioning system  24  operates between ventilation and recirculation modes. In ventilation mode, an inside air inlet is closed and an outside air inlet is opened, drawing fresh air into the interior of the vehicle  20 , and in recirculation mode, the inside air inlet is opened and the outside inlet closed, to recirculate air inside the interior of the first vehicle  20 . 
         [0016]    The air conditioning system  24  switches to recirculation mode in response to the signal received from the detection device  22 . When no signal has been received from the detection device  22 , the air conditioning system  24  switches/remains in the ventilation mode. 
         [0017]      FIG. 3  is a detailed block diagram of the air conditioning system  24 . The air conditioning system  24  includes a control module  242 , a selection module  244 , and an air adjusting module  246 . The control module  242  directs the selection module  244  to select an operating mode for the air adjusting module  246 . When the signal is received from the detection device  22 , the control module  242  directs the selection module  244  to select the recirculation mode from the air adjusting module  246 . When no signal is received from the detection device  22 , the control module  242  directs the selection module  244  to select the ventilation mode for the air adjusting module  246 . 
         [0018]    Referring to  FIG. 4 , in a second embodiment, the air conditioning system  24  can further include a timing module  248 . The timing module  248 , which may be a timer, triggers the control module  242  to determine if the signal is incoming from the detection device  22  in a predetermined time interval, such as two minutes or three minutes. If, after the predetermined time interval, no signal is incoming from the detection device  22 , the control module  242  directs the selection module  244  to select the ventilation mode for the air adjusting module  246 . 
         [0019]    As described, the first vehicle  20  automatically switches to the recirculation mode when the second vehicle  30  is detected within a predetermined distance. Thus, emissions discharged from the second vehicle  30  are prevented from being drawn into the inside of the first vehicle  20 . 
         [0020]    Referring to  FIG. 5 , a method  400  of operating an air conditioning system according to a first embodiment is illustrated. The method  400  includes the following steps. 
         [0021]    In step S 402 , the detection device  22  determines whether a second vehicle  30  is within a predetermined distance of the first vehicle  20 . If so, step S 404  is implemented. If not, the first step S 402  is repeated. 
         [0022]    In step S 404 , the detection device  22  sends a signal to the air conditioning system  24  indicating the second vehicle  30  is within the predetermined distance. 
         [0023]    In step S 406 , the air conditioning system  24  switches to the recirculation mode. 
         [0024]    Referring to  FIG. 6 , a method  500  of operating an air conditioning system according to a second embodiment is shown. The method  500  includes the following steps. 
         [0025]    In step S 502 , the detection device  22  determines whether a second vehicle  30  is within a predetermined distance of the first vehicle  20 . If so, step S 504  is implemented. If not, step S 512  is repeated. 
         [0026]    In step S 504 , the detection device  22  sends a signal to the air conditioning system  24  indicating that the vehicle  30  is within the predetermined distance. 
         [0027]    In step S 506 , the first vehicle  20  determines whether the air conditioning system  24  is currently in the recirculation mode. If so, step S 510  is implemented. If not, step S 508  is implemented. 
         [0028]    In step S 508 , the air conditioning system  24  switches to the recirculation mode. 
         [0029]    In step S 510 , the air conditioning system  24  determines whether a signal is incoming from the detection device  22  after a predetermined time interval. If so, the procedure finishes. If not, step S 512  is implemented. 
         [0030]    In step S 512 , the air conditioning system  24  switches to the ventilation mode. 
         [0031]    According to the methods disclosed, the air conditioning system  24  of the vehicle  20  switches to the recirculation mode when the vehicle  30  is determined to be within the predetermined distance. Thus, the emissions discharged from the vehicle  30  are prevented from being drawn into the interior of the vehicle  20 . 
         [0032]    It is believed that the embodiments and their advantages will be understood from the foregoing description, and it will be apparent that various changes may be made thereto without departing from the spirit and scope of the invention or sacrificing all of its material advantages, the examples hereinbefore described merely being preferred or exemplary embodiments of the invention.