Abstract:
A system and method of detecting fuel theft at a fuel dispenser. The system has a fluid flow meter, a pulser operatively coupled to said fluid flow meter, and a control system in electrical communication with the pulser. The control system is configured to calculate a flow rate of fuel being dispensed from a gasoline dispenser during a single dispensing transaction. The flow rate is sampled at predetermined time intervals during the single dispensing transaction. The system then compares the sampled flow rates to a predetermined flow rate pattern indicative of potential fraud. A shutoff signal is then provided to the dispenser to stop fuel flow through the dispenser if the sampled flow rates are substantially similar to the predetermined pattern.

Description:
FIELD OF THE INVENTION 
     The present invention relates to the art of fuel dispensers. More particularly, the present invention relates to the detection of, and response to, fuel theft. 
     BACKGROUND OF THE INVENTION 
     As fuel prices continue to rise, small businesses and global enterprises find themselves paying more for nearly every input and service needed to bring their products and services to market. Consumers have had to adjust because they must pay more at the grocery store, shopping malls, and to fill up their tanks. Moreover, as fuel prices continue to rise, the incentive to steal fuel becomes greater. In regions of the United States, for example, fuel theft has become a significant cost to station owners. 
     With dispenser and site layouts today, an attendant may never know theft has begun or occurred. Even if the attendant is able to detect theft by observation, they may not know how long it has been since the theft took place or how many people got free fuel (and therefore, information about the theft may not be available). In some cases, surveillance video footage shows multiple people orchestrating fuel theft to fill multiple vehicles over an extended period of time. News media make the problem worse by increasing attention to the issue of fuel theft, and in some instances, clearly describing and illustrating what was done to steal fuel. 
     The present invention recognizes and addresses the foregoing considerations, and others, of prior art constructions and methods. 
     SUMMARY OF THE INVENTION 
     In accordance with one aspect, the present inventions provides a fuel dispenser comprising a fluid flow meter, a pulser operatively coupled to said fluid flow meter, and a control system in electrical communication with and said pulser. Said control system is configured to calculate a flow rate of fuel being dispensed via pulser signals produced by said pulser, periodically sample said flow rate to provide sampled flow rate readings, compare said sampled flow rate readings to a predetermined flow criterion, and shutoff flow of fuel if at least two of said sampled flow rate readings satisfy a predetermined pattern when compared with said predetermined flow criterion. 
     In some embodiments, said predetermined flow criterion is a predetermined flow range. In other embodiments, said predetermined flow rate range is between approximately 0.5 and 2 gallons per minute. In still other embodiments, said control system is configured to begin sampling said flow rate at a predetermined time after dispensing has begun. In some of these embodiments, said pattern occurs when said sampled flow rate readings fall within said predetermined flow rate range a preset number of times during a single dispensing transaction. In still other of these embodiments, said preset number is at least ten. In yet other of these embodiments, said control system is configured to shutoff flow if said sampled flow rate readings fall within said predetermined flow rate range at least ten consecutive times during a single dispensing transaction. 
     In other embodiments, said predetermined pattern includes the flow rate approximately equaling zero a preset number of times during a single dispensing transaction. In these embodiments, the pattern includes the flow rate approximately equaling zero a preset number of consecutive times during a single dispensing transaction. 
     In a preferred method of detecting fuel theft at a fuel dispenser, the dispenser has a flow meter, a pulser operatively coupled to said flow meter, and a control system operatively coupled to said pulser. The method comprises the steps of calculating a flow rate of fuel through said flow meter based on pulses generated from said pulser, sampling said flow rate at predetermined time intervals during a single dispensing transaction to provide sampled flow rate readings, comparing said sampled flow rates to a predetermined pattern, and providing a shutoff signal to said dispenser to stop fuel flow through said dispenser if said sampled flow rates satisfy said predetermined pattern. 
     In some of these embodiments, said predetermined pattern occurs when said sampled readings fall within a predetermined flow rate range a preset number of times during said single dispensing transaction. In some of these embodiments, said preset number of times is at least ten. In yet other of these embodiments, said control system is configured to stop fuel flow when said sampled flow rate readings fall within said predetermined flow rate range for at least ten consecutive times during said single dispensing transaction. 
     In still other embodiments, said predetermined flow rate range is between approximately 0.5 and 2.0 gallons per minute. In other embodiments, the method further comprises the step of providing an alarm indicator if said predetermined pattern is detected. In yet other embodiments, said predetermined pattern includes the sampled flow rate readings indicating flow of zero gallons per minute a preset number of times during said single dispensing transaction. In other embodiments, the method further comprises step of transmitting an alarm signal to a central station. 
     In another preferred method of detecting fuel theft at a fuel dispenser, the method comprises calculating a flow rate of fuel being dispensed from a gasoline dispenser over a single dispensing transaction, sampling said flow rate at predetermined time intervals during said single dispensing transaction to produce sampled flow rate readings, comparing said sampled flow rate readings to a predetermined criterion, and providing a shutoff signal to said dispenser to stop fuel flow through said dispenser if said comparison indicates low flow not expected during normal operation of said dispenser. 
     In some embodiments, said shutoff signal is provided when said sampled flow rate readings fall below a predetermined flow rate threshold a preset number of times during said single dispensing transaction. In some of these embodiments, said preset number of times is at least ten. In still others of these embodiments, fuel flow is shutoff if said preset number of times are consecutive. In other embodiments, the method further comprises the step of obtaining a photograph of the dispenser area if said shutoff signal is provided. 
     The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate one or more embodiments of a system in accordance with the present invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A full and enabling disclosure of the present invention, including the best mode thereof directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended drawings, in which: 
         FIG. 1  is a schematic view of a fuel dispenser in accordance with one embodiment of the present invention; 
         FIG. 2  is a schematic view of a fuel forecourt; and 
         FIG. 3  is a flow diagram showing operation of the fuel dispenser of  FIG. 1  in accordance with an embodiment of the present invention. 
     
    
    
     Repeat use of reference characters in the present specification and drawings is intended to represent same or analogous features or elements of the invention. 
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     Reference will now be made in detail to presently preferred embodiments of the invention, one or more examples of which are illustrated in the accompanying drawings. Each example is provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that modifications and variations can be made in the present invention without departing from the scope or spirit thereof. For instance, features illustrated or described as part of one embodiment may be used on another embodiment to yield a still further embodiment. Thus, it is intended that the present invention cover such modifications and variations. Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be discerned from the description, or may be learned by practice of the invention. 
     Referring to  FIG. 1 , a fuel dispenser  10  delivers gasoline or other liquid fuel to a vehicle  12  through a delivery hose  14  coupled to a nozzle  16  having a spout  18 . A display  13  provides a customer interface that displays price per unit, total cost, gallons (or liters) and other information associated with a fueling transaction. While display  13  may be a purely visual display, it may also be a touch display that allows the customer to make inputs at the dispenser. Alternatively, the inputs may be made by pressing mechanical buttons on the dispenser face. In this illustrative embodiment, delivery hose  14  includes a product delivery line  36  and a vapor return line  34  that are both in fluid communication with an underground storage tank (UST)  40 . A pump  42 , controlled by motor  44 , extracts fuel from UST  40  and provides it to product delivery line  36 . Typically, pump  42  will be a submersible turbine pump (STP) located at UST  40 , although suction systems in which the pump is located within the dispenser housing are contemplated. A single pump  42  and motor  44  may serve a plurality of fuel dispensers  10 , or a single fuel dispenser. 
     A vapor recovery system may be present in fuel dispenser  10 , to recover vapors that the incoming fuel displaces during fueling. In this embodiment, for example, vapor is recovered from the gas tank of vehicle  12  through vapor return line  34  with the assistance of a vapor recovery pump  52  that is driven by a motor  53 . Vapor recovery pump  52  may be a variable speed pump or a constant speed pump with or without a controlled valve (not shown) as is well known in the art. 
     A control system  50  receives information from a pulser  58  operatively coupled to a meter  56  in fuel delivery line  36 . As the fuel passes through meter  56  there is mechanical movement that is detected by pulser  58 . In particular, pulser  58  will generate a pulse train the frequency of which is related to flow though meter  56 . In one preferred embodiment, for example, pulser  58  generates one thousand (1000) pulses per gallon of fuel dispensed and transmits the pulser signal to control system  50 . In other embodiments, the number of pulses per gallon may range between 250 and 5000 pulses. 
     Control system  50  controls a drive pulse source  55  that in turn controls motor  53  and thus recovery pump  52 . Control system  50  may be a microcontroller, a microprocessor, or other electronic systems with associated memory and software programs running thereon to control the various functions of the fuel dispenser including, but not limited to: fuel transaction authorization, fuel grade selection, display and/or audio control. In some embodiments, pump  42  and motor  44  may be controlled by control system  50  directly and provide operating data thereto. 
     A vapor flow sensor  54  may be positioned in vapor return line  34 , which is configured to sense vapor flow within the vapor return line and hydrocarbon concentration to provide a total volume of hydrocarbons recovered from the gas tank of vehicle  12 . In some systems, vapor recovery is dictated by the rate of fuel dispensed, however, in systems equipped with a sensor  54 , vapor recovery operates at least semi-independently of fuel dispensing. 
     Referring to  FIG. 2 , a central fuel station building  62  is located within a fueling environment  60 . Fueling environment  60  includes fuel station building  62 , a plurality of fuel dispensers  10  and a site controller  66  (which typically have an operator terminal associated therewith). Dispensers  10  are fluidly connected to UST  40 , in which is positioned a UST sensor  64  that measures the level of fuel within UST  40 . Sensor  64  may be a float type sensor, a pressure sensor or any other suitable sensor that is sensitive enough to detect minute changes in the present volume of fuel within UST  40 . Most UST sensors  64  are temperature compensated to account for the natural expansion and contraction of the fuel according to the vagaries of the atmospheric temperature. Central station computer  66  is operatively connected to each of dispensers  10  and UST sensor  64 . Additionally, central station computer  66  may be connected to each dispenser pump  42  and motor  44 . A camera  70  may be positioned to photograph one or more areas around dispensers  10  if fraud is detected to capture images for use in prosecution of thieves. 
     Referring to  FIG. 3 , during normal operation, pump  42  would produce pressure in the fuel delivery piping to deliver a normal rate of fuel to the vehicle when the nozzle is fully open, such as ten gallons of fuel per minute. Meter  56  measures this flow rate, causing pulser  58  to produce 10,000 pulses per minute, in this example. Control system  50  receives the pulses and reports correctly that ten gallons are dispensed per minute. If the customer opens the nozzle only partially, the flow rate will be less. There is a minimum flow rate, however, at which the customer would not be expected to dispense fuel for more than a very short period of time. 
     At step  100 , when a transaction is authorized control system  50  allows the customer to begin pumping fuel. At step  102 , control system  50  measures the flow rate at a predetermined time interval (T o ). At step  104 , the flow rate is compared to a predetermined criterion that may be programmed into control system  50 . For example, the predetermined criteria may be a low flow range. 
     If the measured flow is outside the predetermined range, the system returns to step  102  and repeats. If, on the other hand, the measured flow rate is within the predetermined range, at step  106 , a counter is incremented. At step  108 , the counter value is compared to a preset counter value. If the counter value is less than the preset counter value, the system returns to step  102  and repeats. If, in the alternative, the counter value is equal to or greater than the preset counter value, at step  110 , an alarm is produced and flow of fuel is shutoff. Typically, flow of fuel is shutoff by closing the dispenser&#39;s internal valve. The system may be configured so that the valve can only be reset after the alarm condition by an authorized operator. The alarm itself may be silent, audible or visual. For example, a silent alarm may be transmitted to the operator of the service station to indicate theft of fuel has been attempted. In other embodiments, instead of incrementing a counter at step  106 , control system  50  may be configured to store in memory the sampled flow rate and track the number of times the flow rate falls within the predetermined flow rate range. 
     In one preferred embodiment, the predetermined time interval (T o ) may be 1 second. In other preferred embodiments, the predetermined flow range may be between 0.5 and 2 gpm. In some embodiments, if the internally measured flow rate is within the predetermined flow range for any ten measurements during a single transaction, the alarm and shutoff may be initiated. In other embodiments, the internally measured flow rate must fall within the predetermined flow range for ten consecutive time intervals during a single transaction. In this latter case, the incrementing counter may reset if the currently measure flow is outside of the low flow range. It should be understood that additional alarms, both visual and audible may be included in the system to indicate when theft has been detected. Such alarms may be instead of, or in addition to, shutting down the dispenser and may include telephoning law enforcement, sending an e-mail or text message to a contact person, etc. 
     In another preferred embodiment, the criterion at step  104  may be whether the pulse rate indicates flow below a predetermined threshold, such as a zero gallons per minute flow rate. If a zero gpm flow rate is measured, at step  106 , the counter is incremented. At step  108 , the counter value is compared to a preset counter value. If the measured counter value is greater than the preset counter value, at step  110 , an alarm is triggered and the dispenser is shut off. In this embodiment, the system detects a pattern of start/stop intervals, which may be indicative of theft. Typically, a thief will turn the pulser a few twists every few seconds so pump  42  does not shut off. Thus, control system  50  is programmed to detect various predetermined patterns in flow rate that may be indicative of theft. 
     While one or more preferred embodiments of the invention are described above, it should be appreciated by those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope and spirit thereof. It is intended that the present invention cover such modifications and variations as come within the scope and spirit of the appended claims and their equivalents.