FUEL DISPENSER

Abstract: The invention provides a fuel dispenser for a dispensing system having a receiver capable of receiving fuelling parameters transmitted from the vehicle. The fuelling parameters relate to information about tank size, ullage, maximum allowed fuelling rates and maximum fuelling rates as a function of ullage, among others. Based on these fuelling parameters, the fuel dispenser controls the fuelling operation to optimize fuel delivery and minimize fuel spillage while abiding by both vehicular and regulatory limitations, such as maximum allowable delivery rates. Control of the fuelling operation may vary from simply adjusting the delivery rate to a maximum allowed by the vehicle to defining a fuelling schedule for the entire fuelling operation wherein the fuelling schedule defines a fuelling process which varies flow rates throughout the fuelling operation as necessary to optimize fuelling. Additionally, the dispenser may continuously adjust the maximum fuelling rate throughout the fuelling operation based upon a fuelling parameter defining the maximum fuelling rate as a function of ullage.

Description: FUEL DISPENSER The present invention relates generally to fuel dispensers and, more particularly, to fuel dispensers for precisely delivering and controlling the rate of fuel flow to a vehicle based upon information received from the vehicle during a fuelling operation. In some countries regulations limit vehicle fuelling to set maximum rate in order to limit spillage from vehicle fuelling operations. The current technology (i.e. prior to this invention) for restricting fuel delivery rate on fuel dispensers is to install restrictive orifices at accessible points in the delivery system and/or various hose and nozzle configurations (known as hanging hardware,) accordingly. The accuracy of restricted orifices and hanging hardware inherently suffers from fluctuations in system feed pressure. System feed pressure is affected by a number of variables including the number of active fuelling positions, clogged fuel filters, kinked hoses and other deteriorating components along a fuel delivery path. The requisite restriction is dependent upon site specifics, such as, but not limited to, pumping device capacity, pipe diameter, pipe length, head height, hose diameter, hose length and nozzle type. These factors prevent effective factory presetting of desired fuel delivery rates. Moreover, orifices and hardware are subject to tampering, removal or substitution in an effort to defeat flow restrictions. When fuel pumps incorporating the current technology are checked for compliance with the regulations, the testing authority will check the highest flow delivery hose, typically the hose closest to the main turbine pump, with all other hoses inactive. Once adjustments are made to limit the high-flow hose the lower flow hoses will inherently deliver below the maximum allowable rate, reducing service station throughput for a given number of outlets. The situation is exacerbated when multiple pumps are active. Under these situations, even the highest flow hose will often deliver significantly less than 10 GPM. A further disadvantage of current fuel dispensers is the inability to automatically compensate for deteriorating components which nominally reduce flow. Components which often reduce flow include clogged fuel filters and kinked hoses. The applicants' invention allows fuelling optimization even when the system components are not optimum. For example, as the fuel filter fills with debris, the flow control signal to the system fuel pump is increased in an amount to precisely compensate for any flow rate loss. According to the present invention there is provided a fuel dispenser comprising a fuel delivery path, a receiver adapted to receive at least one vehicle fuelling parameter from a vehicle to be fuelled, fuel rate control means for controlling the rate of fuel to the vehicle during a fuelling operation and a control system operatively associated with the receiver and the flow rate control means for regulating the fuel flow rate in the fuel delivery path during the fuelling operation based on parameters received from the vehicle to optimize the fuelling operation. Optimizing the fuelling operation from parameters received from the vehicle to be fuelled enables the supply capacity to the dispenser to be increased, while ensuring that the maximum delivery rate is not exceeded and that spillage is minimised. Controlling the dispenser in this way enables optimum flow rates to be achieved even on multiple pump dispensers, regardless of the number of hoses in use at a given time. Preferably the control system is arranged to control the control means such that a desired flow rate is not exceeded, so that the dispenser complies with regulations. The control system advantageously sets the desired fuel flow rate to the maximum allowable rate during a portion of the fuelling operation. This enables fuelling operations to be optimised by maximising the fuelling rate throughout at least part of the fuelling transaction. The control system advantageously is arranged to regulate the fuel flow rate independence on fuel tank ullage. This enables the flow rate to be reduced as the fuel tank becomes full, thereby minimising spillage. The desired flow rate may be a predetermined average flow rate during a portion of the fuelling operation, permitting regulatory mandates to be temporarily exceeded whilst still maintaining a regulated average. Preferably the dispenser is configured to ramp up and/or ramp down the desired flow rate in the delivery path to/from a higher flow rate, thus minimising spillage at commencement and/or termination of the fuelling operation. Ramping up the flow rate at the start of a fuelling operation minimises the initial surge and spit-back, while ramping down the flow rate at the end of the fuelling operation reduces the chance of spillage at the end of fuelling. Preferably the dispenser further comprises a control valve in the fuel delivery path, which valve regulates fuel flow. A flow transducer may be provided to supply a signal to the control system representing volume of fuel flow in the fuel delivery path. The control system may hold a reference flow rate value against which the actual flow rate may be compared and adapted accordingly. The control system may control the flow rate in the delivery path to provide a predetermined flow rate under varying dynamic conditions, such conditions including pressure changes and component failure or deterioration. This features enables fuelling to be optimised despite adverse conditions. Advantageously the control system is configured to reduced the desired flow rate in response to detecting one or more premature automatic shut-offs which indicate excessive turbulence in the fuel neck and increase the risk of spilling fuel. Further protection from spillage is provided by controlling the flow rate and delivery path to assist topping off of a fuelling operation. The control system can be configured to indicate when a desired flow rate is not achievable, thereby identifying that the dispenser or fuel supply need attention, for example the filters may need changing. Several embodiments of the present invention will now be described by way of example only with reference to the accompanying drawings of which: Figure 1 is an elevational and partial sectional view of a typical fuel dispenser having a vapour recovery system according to an embodiment of the present invention; Figure 2 is a block diagram illustrating a fuel dispenser's flow control system constructed according to an embodiment of the present invention; Figure 3 is a block diagram illustrating an alternative embodiment of a fuel dispenser's flow control system constructed according to the present invention; Figure 4 is a flow chart depicting a control process for controlling the flow rate with respect to a reference flow rate according to one embodiment of the current invention; Figure 5 is a flow chart depicting a control process for ramping down the fuelling rate according to one embodiment of the current invention; Figure 6 is a flow chart depicting a control process for ramping up the fuelling rate according to one embodiment of the current invention; Figure 7 is a flow chart depicting a control process for providing an average flow rate according to one embodiment of the current invention; Figure 8 is a flow chart depicting a control process for compensating for dynamic conditions according to one embodiment of the current invention; Figure 9 is a flow chart depicting a control process for compensating for component deterioration or fuel passageway obstruction according to one embodiment of the current invention; Figure 10 is a flow chart depicting a control process for controlled topping off according to one embodiment of the current invention; Figure 11 is a flow chart depicting a control process for reducing flow rates in response to a premature nozzle shutoff according to one embodiment of the current invention; Figure 12 is a flow chart depicting a control process for controlling flow rates in response to a certain number of premature nozzle shut-offs according to one embodiment of the current invention; Figure 13 is a flow chart depicting a control process for reducing flow rates in response to a certain number of nozzle shut-offs during a predetermined period of time according to one embodiment of the current invention; Figure 14 is a flow chart depicting a control process for indicating a flow rate is not achievable according to one embodiment of the current invention; Figure 15 is a flow chart depicting a control process for delivering fuel at a set, maximum fuelling rate based on fuelling parameters received from the vehicle; Figure 16 is a flow chart depicting a control process for fuelling at a maximum flow rate as a function of ullage based on fuelling parameters received from the vehicle; Figure 17 is a flow chart depicting a control process for fuelling a vehicle at a maximum fuelling rate and ramping down the fuelling rate near the end of the fuelling operation based on fuelling parameters received from the vehicle; Figure 18 is a flow chart depicting a control process for providing a defined average fuelling rate over a portion or the entire fuelling operation based on parameters received from a vehicle; and Figure 19 is a flow chart depicting a control process for providing a fuelling schedule for a portion of or the entire fuelling operation wherein fuelling rates are maximized based on fuelling parameters received from a vehicle; Referring to Figure 1 an automobile 100 is shown being fuelled from a fuel dispenser 10. A spout 2 of nozzle 4 is shown inserted into a filler pipe 102 of a fuel tank 104 during the refuelling of the automobile 100. A fuel delivery hose 6 having vapour recovery capability is connected at one end to the nozzle 4, and at its other end to the fuel dispenser 10. As shown by the cutaway view of the interior of the fuel delivery hose 6, a fuel delivery passageway 8 is formed within the fuel delivery hose 6 for distributing fuel pumped from an underground storage tank 12 to the nozzle 2. Fuel is typically pumped by a delivery pump system 16 located within tank 12. The fuel delivery passageway 8 is typically annular within the delivery hose 6 and tubular from within the fluid dispenser 10 to the tank 12. The fuel delivery hose 6 typically includes a tubular vapour recovery passageway 14 for transferring fuel vapours expelled from the vehicle's fuel tank 104 to the underground storage tank 12 during the refuelling of the vehicle 100. A vapour recovery pump 28 provides a vacuum in the vapour recovery passageway 14 for removing fuel vapour during a refuelling operation. The vapour recovery system using the pump 28 may be any suitable system such as those shown in U.S. Patent Nos. 5,040,577 to Pope, 5, 195,564 to Spalding, 5,333,655 to Bergamini et al, or 3,016,928 to Brandt. The invention is equally useful on dispensers that are not vapour recovery dispensers. The fuel delivery passageway 8 typically includes a control valve 22, a positive displacement flow meter 24 and fuel filter 20. The fuel dispenser 10 also includes a control system 26 operatively associated with the control valve 22, flow meter 24 and the fuel pump 16. In the preferred embodiment, the control valve 22 acts as a flow modulator, and the flow meter 24 acts as a fuel flow transducer. A transmitter 106 in vehicle 100 is used to transmit fuelling parameters or other information relating to the vehicle 100 to a receiver 25 associated with the control system 26 of the fuel dispenser 10. In the preferred embodiment, an RF communication link is established between the transmitter 106 of the vehicle 100 and the transmitter 25 of the fuel dispenser 10. One or more antennas 27A, 27B may be used to facilitate reception of the fuelling parameters and other information sent from the vehicle 100. Although this specification focuses primarily on sending information in one direction from the vehicle 100 to the dispenser 10, bi-directional communication between the vehicle 100 and dispenser 10 may be preferable in certain embodiments. For bi-directional communications, transceivers (including transponders) in the vehicle 100 and in fuel dispenser 10 are preferred. The dispenser may transmit various types of information to the vehicle. Transaction information may include amount of sale, amount of fuel dispensed or other billing data. The communications link may also provide for payment of fuel delivered and products or services purchased at the dispenser or store. Additionally, any type of communication link between the vehicle 100 and dispenser 10 is acceptable. For example, infrared, optical, acoustic, electromagnetic or electrical communications may be used. The embodiment discussed in detail herein provides an RF communication link between the transmitter 106 of the vehicle 100 and the receiver 25 of the fuel dispenser 10. The control system 26 of fuel dispenser 10 is adapted to receive fuelling parameters communicated from the vehicle 100, such as tank size, ullage, amount of fuel remaining in tank, maximum fuelling rate and maximum fuelling rate as function of ullage, vehicle type, vehicle identification, fuel type, diagnostics, onboard vapour recovery capability. among others, and control the fuel delivery rate in order to optimize the fuelling operation. In one embodiment, the controller will simply determine the maximum allowable fuel delivery rate based on fuelling parameters received from the vehicle 100 and adjust the delivery rate of fuel to the maximum that the vehicle can accept without causing excessive spillage. The received vehicle fuelling parameters may simply provide a single, maximum fuel delivery rate, not to be exceeded during any portion of the fuelling operation regardless of ullage. If the vehicle transmits a parameter relating to the maximum fuelling rate as a function of ullage, then the controller 26 may continuously adjust the fuel delivery rate to the maximum allowable based on the corresponding ullage value. Controlling a fuelling operation based on fuelling parameters received from the vehicle 100 provides significant flexibility in controlling and defining a fuelling operation. The vehicle's ullage information allows the controller 26 to determine the amount of fuel required to fill the tank; therefore, allowing the control system 26 to accurately determine or predict the end of the fuelling operation. When the control system 26 can predict the end of the fuelling operation, fuel can be delivered at higher rates, for longer periods of time, without spilling fuel. For example, once the amount of fuel needed to fill the tank is determined, the control system 26 can determine precisely when to reduce the flow rate to prevent spilling fuel as the tank 104 reaches capacity. The control system 26 may also control ramping up the fuel rate at the beginning of the fuelling operation in order to minimize any initial surge created by the on-rush of fuel. Additionally, the maximum flow rate throughout the fuelling operation is controllable based on any number of factors, alone or in combination, such as: 1) maximum allowable fuel delivery rates set by the vehicle, 2) maximum allowable fuel delivery rates set by government regulations, and/or 3) maximum allowable fuel delivery rate as a function of fuel tank ullage. Furthermore, these maximum allowable fuel delivery rates can be either instantaneous or an average taken over a portion or all of the fuelling operation. If a regulatory agency set a maximum allowable average fuel delivery rate of 10 GPM, the control system 26 could exceed 10 GPM during a portion of the fuelling operation in order to provide an overall 10 GPM average fuel delivery rate throughout the entire fuelling operation. Such averages may also be obtained during any select portion of the fuelling operation. These averages are obtained in conjunction with staying within any of the maximum allowable fuelling delivery rates defined by the vehicle, government or other limiting source. Thus, applicants' invention allows precise control over the fuelling operation while taking into consideration fuelling parameters of the vehicle and/or regulatory mandates in order to optimize fuelling efficiencies and minimize fuel spillage. Preferably, fuel delivery at the beginning and end of the fuelling operation is controlled to reduce fuel surge and spillage. At the beginning of the fuelling operation, the flow rate is ramped up in a manner which provides for a smooth transition from a zero flow rate to the desired fuelling rate. Likewise, the fuelling rate may be controlled in a manner providing a smooth transition from the desired delivery rate to a zero delivery rate in order to reduce the possibility of spilling fuel at the end of the fuelling operation. Turning now to Figure 2, the preferred embodiment employs a fuel flow transducer 24 which produces a fuel volume signal 34 by generating a digital transition for a given specific volume through the fuel flow transducer 24. The output of the fuel flow transducer 24 is fed to the control system 26. The control system 26 measures the period between the transitions of the fuel volume signal 34 to yield a numerical value inversely proportional to a flow rate through the fuel passageway 8. Alternatively, the control system 26 may count transitions in the fuel volume signal 34 over a fixed period of time to yield a numerical value directly proportional to the flow rate of fuel through the fuel passageway 8. With either method, the flow rate is compared with a desired reference value by the control system 26 to obtain system error. The reference signal may be stored or calculated by the control system 26 or read from a set delivery rate reference source 30 within or associated with the control system 26 via a delivery rate reference signal 36. The reference value may be a numerical coefficient calculated by the control system 26 or derived from an external source such as an oscillator whose input is processed in similar fashion to the flow measurement device. The reference may represent the instantaneous maximum allowable delivery rate, a value representative of the desired system delivery rate or a value representing a flow-rate-dependent result. The result of the comparison of the flow rate value and reference value represents an error value which is a scalar of the difference between the desired and actual fuel delivery rate. The error value is inputted into a conventional proportional-integral-derivative (PID) algorithm by the control system 26 to derive a forcing function 32 which is outputted to a flow rate modulator 22. The flow rate modulator 22 may include an electromechanically driven valve or any suitable controllable flow restricting device. The flow rate modulator 22 is preferably actuated in proper phase with a servo loop. Alternatively, the forcing function may modulate the pumping rate of variable speed fuel pump 28 as shown in Figure 3. Those of ordinary skill in the art are able to program control system 26 with a suitable PID algorithm. The preferred embodiments use a PID feedback control system with greater than unity gain. The PID feedback control system is easily implemented and the PID coefficients are chosen to compensate for any mechanical or electrical time constants and delays present in the fuel delivery system of the fuel dispenser 10, thereby effecting improved regulative response to dynamic changes imposed by site, dispenser, vehicle, user or other variables which would otherwise affect unregulated fuel delivery rates. The feedback control system may be modified and the regulatory functions still effectively implemented by deleting the derivative term at the compromise of delivery rate overshoot, undershoot or system response time. Alternatively, a unity or less than unity gain feedback control system may be implemented by modulating the flow rate modulator 22 or variable speed pump 28 at a rate equal to or less than the sum of mechanical and electrical system delays at greater compromise of delivery rate overshoot, undershoot or system response time. Those of ordinary skill in the art will recognize that other feedback systems of lesser or greater complexity and of lesser or greater performance may be implemented to achieve a desired fuel delivery rate. However, the preferred embodiment will include a reference signal or value representative of the desired delivery rate, a feedback signal or value comprising or representing the actual delivery rate, a control system that accepts the reference and feedback signals to derive a forcing function, and a flow controlling device receiving the forcing function capable of modulating the fuel delivery rate. Systems requiring a lesser degree of accuracy or having a very precise and controllable flow rate modulator may not require feedback. In operation, the control system 26 (for either Figure 2 or Figure 3) provides a variety of flow rate control functions to achieve a flow-rate-dependent result based on fuelling parameters received from the vehicle 100 and/or regulatory mandates. The control system may be configured to control the flow rate according to a reference flow rate. As discussed above, the reference may come from within the control system 26, be received from the reference 30 or be received from the dispenser's receiver 25. For the discussion herein, the reference 30 is calculated by the control system 26 based on information received from the vehicle 100 and/or regulatory mandates and represents a desired instantaneous flow rate. The reference may remain constant or continuously vary as desired to effect desired instantaneous flow rates or a defined fuelling schedule. The determination of the reference and any fuelling schedule based on vehicle fuelling parameters is described in detail below in association with Figures 15 through 19. A description of the various types of delivery flow rate control operations are described immediately below in association with Figures 4-14. The present invention is capable of combining various types of delivery control to optimize fuelling during a fuelling operation. Figure 4 depicts a basic control outline for a typical fuelling operation to obtain a desired reference flow rate. The reference may be constant or varied, as desired, throughout the fuelling operation. Block 40 indicates the beginning of a fuelling operation During the fuelling operation, the controller determines the desired flow rate based on fuelling parameters from the vehicle and/or regulatory mandates and whether the actual flow rate is equal to the reference or desired flow rate at decision block 42. If the rates are not equal, the flow rate is adjusted toward the reference or desired flow rate at block 44. Once the flow rate is adjusted at block 44, the controller returns to decision 42 to determine whether the actual and reference flow rates are equal. The flow rate is continually adjusted until the actual and reference flow rates are equal. Once the reference flow rate is achieved, the controller will deliver fuel at a constant flow rate at block 46. The controller 26 will check to see if the fuelling operation is at an end at decision block 48. If the fuelling operation is at an end, the controller 26 will stop fuelling at block 50. If the fuelling operation is not at an end, the controller 26 returns to decision block 42 to determine if the actual and reference or desired flow rates are equal. The control system will constantly adjust the flow rate to match the desired reference. The process is repeated until fuelling is stopped. Figure 5 is a flow chart setting out the basic control process for ramping down the fuelling rate near the end of a fuelling operation. The fuelling operation begins at block 52. The controller 26 determines whether to ramp down the fuelling rate at decision block 54. The fuelling rate is decreased accordingly at block 56, if necessary. Once the fuelling rate is decreased, the control system 26 returns to decision block 54. When the fuelling rate does not require ramping down, the control system 26 causes fuel to be delivered at a constant rate at block 58. The control system 26 next checks for an end to the fuelling operation at decision block 60. If the fuelling operation is at an end, the controller 26 stops fuelling at block 62. If the fuelling operation is not at an end, the control system 26 returns to decision block 54 and reiterates the process. Those of ordinary skill in the art will understand that the terms ramp or ramping will include not only constant and variable flow rate changes, but also abrupt step changes in flow rates. Ramping down the flow rate may be used to slow the rate of fuelling for pre-set sales, assist the customer in smoothly ending the fuelling operation, or adjust the flow rate to a lower desired or reference flow rate in order to optimize fuelling and minimize spillage. Likewise, the system may ramp up the flow rate from a reduced value to mitigate the initial surge at the onset of fuelling to reduce fuel spillage or to increase the fuelling rate to a desired or reference level. Figure 6 depicts a flow chart for ramping up the flow rate. The fuelling operation begins at block 64. During the fuelling operation, the control system 26 determines whether it is necessary to ramp up the fuelling rate at decision block 66. If the fuelling rate needs increased, the control system 26 increases the fuelling rate at block 68 and returns to decision block 66 to determine if a further increase is necessary. When the fuelling rate does not require an increase, the control system 26 causes the delivery of fuel at a constant rate at block 70. The control system 26 determines whether the fuelling operation is at an end at decision block 72. If the fuelling operation is at an end, fuelling is stopped at block 74. If the fuelling operation is not at an end, the control system 26 returns to decision block 66 to reiterate the process. Figure 7 provides a flow chart outlining a basic control process for providing a desired average flow rate during a portion of the fuelling operation. The fuelling operation begins at block 76. The control system determines whether or not to provide a desired average flow rate at decision block 78. If a desired average flow rate is required, the flow rate is adjusted by adjusting the reference in a manner calculated to reach the desired average flow rate at block 80. Providing an average flow rate allows the controller to deliver fuel at an average flow rate throughout any portion of the fuelling operation. For example, if the average fuelling rate has to be 10 GPM or less during all or part of the fuelling operation, the dispenser may deliver fuel significantly above 10 GPM to compensate for the lower delivery rates during the beginning and/or end of the fuelling operation or limitations provided by the vehicle or regulatory mandate. This feature achieves two major goals: first, a station operator improves customer throughput and second, customers receive fuel in a faster and safer manner. Such control is currently unavailable in the industry. Once the average flow rate is achieved, the control system causes fuelling at a constant rate at block 82. The control system determines whether the fuelling operation is at an end at decision block 84. If the fuelling operation is at an end, fuelling is stopped at block 86. If the fuelling operation is not at an end, the control system 26 returns to decision block 78 to further check and/or adjust the fuelling rate to provide the desired average flow rate. The control system 26 may also control the rate of flow in the delivery path to provide a predetermined average rate of flow during various portions of or the entire fuelling operation. Figure 8 is a flow chart depicting a control process similar to that of Figure 7. Figure 8 provides a control process capable of compensating for dynamic changes in the fuelling operation. The cause of these dynamic changes are often due to pressure changes in the fuel delivery system when multiple dispensers are turned on or off during the fuelling operation, or a customer manually or accidentally adjusts the fuelling rate or causes a premature cut-off. Current technology does not allow the dispenser to recover and continue to deliver fuel at a high average delivery rate. Prior systems are restricted to delivering fuel at the maximum flow rate allowed by the mechanical flow restrictors. In most cases, reduced system feed pressure prevents fuelling at rates equal to the mechanical flow restrictors' maximum allowable flow rate. The applicants' invention overcomes the inherent limitations of the mechanical restrictors by allowing fuel delivery rates to instantaneously and periodically rise above the average flow rates set by governmental regulations to provide an average flow rate meeting these regulations. The fuelling operation begins at block 88. The control system 26 determines whether there is a need to compensate for a dynamic change occurring during the fuelling operation at decision block 90. If such a change is necessary, the control system 26 adjusts the flow rate to compensate for the condition at block 92 and returns to decision block 90 in an iterative manner. If the control system does not need to compensate for a dynamic condition, the fuelling rate is held constant at block 94. The control system 26 determines whether the fuelling operation is at an end at decision block 96. If the fuelling operation is at an end, the control system 26 stops fuelling at block 100. If the fuelling operation is not at an end, the control system 26 returns to decision block 90 to determine whether the fuelling rate requires further compensation. Figure 9 depicts a flow chart outlining a control process for compensating delivery rates for deteriorating components which nominally reduce flow, such as fuel filters and kinked hoses, or other obstructions within the fuel passageway 8. Currently available fuel dispenser systems are unable to utilize excess site delivery capacity to automatically compensate for conditions negatively affecting flow. Typically, additional restrictions simply further reduce flow rates substantially below allowed delivery rates. The current invention overcomes the limitations of the prior art by the need for mechanically restrictive orifices and utilizing a control valve 22. Many dispensers already include such a valve. When deteriorating components or passageway obstructions reduce flow rates, the current invention can use excess delivery capacity in conjunction with the control valve 22 in an effort to compensate for additional restrictions. The fuelling operation begins at block 102. The control system 26 determines whether or not to compensate for component deterioration or other obstructions unduly limiting delivery rates at decision block 104. If compensation is required, the control system adjusts the flow rate in an effort to compensate for the reduced flow at block 106 and returns to decision block 104 in an iterative manner. Once compensation is complete, the control system 26 causes fuelling at a constant rate at block 108. The control system 26 next determines whether the fuelling operation is at an end at decision block 110. If the fuelling operation is at an end, fuelling is stopped at block 112. If the fuelling operation is not at an end, the control system 26 returns to decision block 104 in an iterative manner. Equally important as optimizing the delivery of fuel during a fuelling operation is minimizing the amount of fuel spilled during the operation. The enhanced control over the fuelling operation provided by the current invention minimizes the amount of fuel spilled by controlling flow rates in a manner reducing the possibility of fuel spills. Figure 10 is a flow chart depicting a control process for assisting a user in topping off a fuelling operation in a manner minimizing the potential for spilling fuel. The fuelling operation begins at block 114. Nearing the end of the fuelling operation, the control system 26 determines whether or not the user is at or near a topping off point in the fuelling operation. The system may recognize that the topping off point is near at decision block 116 when automatic shut-offs begin to occur, a pre-set sale or amount is being reached, or the fuel dispenser has received information from the operator or vehicle regarding the amount of fuel necessary to fill the tank. If a topping off point in the fuelling operation occurs, the control system 26 reduces the flow rate in a manner assisting topping off and minimizing the potential for spilling fuel at decision block 118 and returns to decision block 116. If the system is not near the topping off point, the control system 26 continues fuelling at block 120. The control system 26 subsequently determines whether the fuelling operation is at an end at block 122. If the fuelling operation is at an end, fuelling is stopped at block 124. If the fuelling operation is not at an end, the control system 26 returns to decision block 116 in an iterative manner. By reducing the flow rate to zero in a controlled fashion, the slow, spill prone, manual topping off method currently used will be replaced by a quicker and safer fuelling operation. Figures 11-13 depict a control process for reducing flow rates when one or more premature nozzle shut-offs occur in sequence or during a predetermined period of time. In Figure 11, the fuelling operation begins at block 126. The control system 26 determines whether a premature nozzle shutoff has occurred at decision block 128. If a shutoff has occurred, the flow rate is reduced in a manner minimizing the potential for spilling fuel, yet attempting to optimize the fuelling operation at block 130. The control system 26 returns to decision block 128 in an iterative manner. If there is no premature nozzle shutoff, the fuelling operation is continued at block 132 until the fuelling operation reaches an end. The control system 26 determines whether the fuelling operation reaches an end at decision block 134. If the fuelling operation is at an end, fuelling is stopped at block 136. If the fuelling operation is not at an end, the control system 26 returns to decision block 128 in an iterative manner. In Figure 12, the fuelling operation begins at block 138. The control system 26 determines whether a certain number of premature nozzle shut-offs have occurred at decision block 140. If such a number has occurred, the flow rate is reduced accordingly at block 142 and the control system 26 returns to decision block 140 in an iterative manner. If the certain number of premature nozzle shut-offs have not occurred, fuelling is continued at block 144 and the control system looks for an end to the fuelling operation at decision block 146. If the fuelling operation is at an end, fuelling is stopped at block 148. If the fuelling operation is not at an end, the control system 26 returns to decision block 140 in an iterative manner. A further refinement of the control process of Figure 12 is that of Figure 13. The fuelling operation begins at block 150. The control system 26 determines whether a certain number of nozzle shut-offs occur within a predetermined period of time at decision block 152. If such condition occurs, the flow rate is reduced accordingly to minimize fuel spillage while optimizing the fuelling operation at block 154. Once the flow rate is reduced, the control system 26 returns to decision block 152 in an iterative manner. If the nozzle shutoff condition is not satisfied, the control system 26 continues fuelling at block 156 and looks for an end to the fuelling operation at decision block 158. If the fuelling operation is at an end, fuelling is stopped at block 160. If the fuelling condition is not at an end, the control system 26 returns to decision block 152 in an iterative manner. Another advantage of the current invention is the ability to provide various warnings or indications of problems associated with the delivery path. Among other indications, the current system may be configured to indicate when a certain flow rate is not achieved or unachievable, the fuel filter is clogged or needs replaced, a delivery hose is deformed, or the delivery path is otherwise obstructed. Figure 14 depicts a basic control process allowing the control system 26 to indicate when one or more of the above-mentioned problems arise during a fuelling operation. The fuelling operation begins at block 162. The control system 26 determines whether or not the desired flow rate is achievable at decision block 164. If the desired flow rate is unachievable, the control system 26 indicates that the flow rate is not achieved at block 166. The control system next attempts to determine whether the filter is causing the reduced flow rates at decision block 170. If the filter is the problem, the control system 26 indicates that the filter needs attention at block 172. The control system 26 next determines whether or not the reduced flow rates are caused by a deformed or kinked dehvery hose at decision block 174. The control system 26 will also progress to decision block 174 if the fuel filter is not causing reduced flow. If a hose is deformed, the control system 26 indicates this at block 176 and proceeds to determine whether or not the delivery path is otherwise obstructed at decision block 178. The control system 26 also progresses to decision block 178 after a determination that the dehvery hose is not causing the reduced flow. If the dehvery path is otherwise obstructed, the control system 26 will indicate so at block 180 and continue fuelling at block 168. If the dehvery path is not otherwise obstructed, the control system 26 will continue fuelling at block 168. If the desired flow rate is achievable, as determined at decision block 164, the control system 26 will continue fuelling at block 168. At this point, the control system 26 determines whether the fuelling operation is at an end at decision block 182. If the fuelling operation is at an end, fuelling is stopped at block 184. If the fuelling operation is not at an end, the control system 26 returns to decision block 164 in an iterative manner, further checking delivery rates. The desired flow rate (or reference) is controlled as desired for each fuelling operation. Figure 15 depicts a control process for determining a maximum, set flow rate for all or a portion of the fuelling operation. The process begins at block 200 and receives fuelling parameters from the vehicle at block 202. From the fuelling parameters, the control system 26 determines the maximum flow rate to be used for most of the fuelling operation at block 204. The reference is set to the determined maximum fuelling rate at block 206. Accordingly, the control system 26 controls the dispenser to fuel at the maximum rate throughout the fuelling process at block 208 until the fuelling operation is over at block 210. The control process of Figure 16 continuously adjusts the maximum fuelling rate as a function of ullage. The process begins at block 212 and receives fuelling parameters from the vehicle at block 214. Preferably, ullage is determined at block 216 and the maximum flow rate for that particular ullage is determined at block 218. Controlling the fuelling as a function of ullage depends on receiving parameters from the vehicle providing this information or information which allows the control system 26 to calculate fuelling rates for various ullage values. The vehicle may provide the ullage information directly or information sufficient for the dispenser to calculate or look up ullage or other information in a database having information related to the vehicle's make and model. Once the maximum flow rate is determined for a particular ullage value, the reference is set equal to the determined maximum flow rate at block 220. The control system 26 will continuously monitor for the end of the maximum fuelling portion at block 222. If the end of the maximum fuelling portion is reached, the process ends at block 224. If the maximum fuelling portion is not near an end, the process loops back to a portion of the program determining ullage. The control system 26 may receive the updated ullage values from additional fuelling parameters from the vehicle 100 or may calculate new ullage values based on the original ullage value at the beginning of the fuelling operation less the amount of fuel delivered since the beginning of fuelling operation. The fuelling process of Figure 17 is exemplary of combining fuelling parameters received from the vehicle 100 and parameters known by the dispenser in order to optimize fuelling and minimize fuel spillage. The process begins at block 226 and fuelling parameters are received at block 228. The ullage value is determined at 230 and the maximum fuelling rate for the entire fuelling operation or for a specific ullage value is determined at block 232. The control system 26 determines whether the fuelling operation is near an end based on additional fuelling parameters from the vehicle 100 or on the original ullage value and the amount of fuel delivered since the beginning of the fuelling operation at block 234. If the fuelling operation is not near an end, the process loops back to determine a new ullage value at block 232 or by receiving additional fuelling parameters from the vehicle at block 228. Optionally, the control system 26 could fuel at a set maximum rate for substantially all of the fuelling operation and loop back to block 232. If the fuelling operation is near an end, the control system 26 continuously adjusts the reference value down to zero in manner minimizing spillage yet maximizing flow rates in order to minimize the length of time required to fuel the vehicle 100. Once the fuel rate is ramped down to zero at block 236, the process ends at block 238. Similarly, the operation may include ramping up to a maximum fuelling rates and minimize surge or spillage according to parameters defined by the dispenser prior to operating at parameters based on information received from the vehicle 100. The control process of Figure 18 provides a fuelling operation wherein the flow rate during all or a portion of the fuelling operation is adjusted to a predefined average. The process begins at block 240 where fuelling parameters are received from the vehicle at block 242. Ullage is determined at block 244 and the fuelling rate is determined to provide a predefined average at block 246. The average may be determined in numerous ways. For example, the control system 26 may determine ullage values and the amount of fuel required to fill the vehicle's fuel tank and provide instantaneous flow rate adjustments throughout the fuelling process to obtain the predefined average. Optionally, the control system 26 may calculate the amount of fuel required to fill the vehicle's fuel tank and determine a fuelling schedule for the entire fuelling operation which will provide an average fuel rate for the overall fuelling operation or a portion thereof. Typically, the control system 26 will monitor for the end of the fuelling operation at block 248. If the end of the fuelling operation is not near, the process will loop back to determine ullage values as desired. If the operation is near end, the process ends at block 250 or goes into a ramp down routine to minimize spillage. The control process of Figure 19 determines a defined fuelling schedule for the entire fuelling operation or a portion thereof based on parameters received from the vehicle. The process begins at block 252 and the control system 26 receives fuelling parameters from the vehicle at block 254. UUage values are determined at block 256 and preferably, the maximum fuelling rate as a function of ullage is determined at block 258. Based on these parameters, the control system 26 determines a fuelling schedule for the entire fuelling operation or a portion thereof to optimize fuelling at block 260. The schedule may attempt to maximize flow rates throughout the entire fuelling operation or a portion thereof or provide an overall average flow rate. Once the schedule is defined, the control system 26 controls the fuelling operation according to the defined schedule at 262 and ends the operation at 264. Preferably, the ramping up and down of the fuelling rates at the beginning and end of the fuelling operation is controlled according to the fuelling schedule to provide the desired flow rate in addition to minimizing fuel surge and spillage. Notably, the control system 26 may control the fuelling operation to maximize the fuelling operation as described above while taking into consideration regulatory mandates or vehicle limitations. For example, fuelling processes where the control system 26 attempts to continuously maximize flow rates throughout the entire operation will also take into consideration any maximum instantaneous or average flow rate limitations imposed by the dispenser, vehicle, site or regulatory agency. In short, applicants' invention optimizes fuelling while minimizing spillage, all while staying within physical and regulatory limitations.

Claims: CLAIMS 1. A fuel dispenser comprising a fuel delivery path, a receiver adapted to receive at least one vehicle fuelling parameter from a vehicle to be fuelled, fuel rate control means for controlling the rate of fuel to the vehicle during a fuelling operation and a control system operatively associated with the receiver and the flow rate control means for regulating the fuel flow rate in the fuel delivery path during the fuelling operation based on the parameters received from the vehicle to optimize the fuelling operation. 2. A fuel dispenser comprising: a fuel delivery path; a receiver adapted to receive at least one vehicle fuelling parameter from a vehicle to be fuelled; flow rate control means for controlling the flow rate of fuel to the vehicle during a fuelling operation; and a control system adapted to receive the parameters from the receiver and actively control the flow rate control means such that a desired flow rate is not exceeded. 3. The dispenser of claim 1 or 2, wherein the at least one received vehicle fuelling parameter relates to the maximum allowable fuel delivery rate and the control system sets a desired fuel flow rate to the maximum allowable fuel delivery rate during a portion of the fuelling operation. 4. The dispenser of claim 1, 2 or 3, wherein the at least one received fuelling parameter further relates to maximum flow rate as a function of ullage and the control system regulates the fuel flow rate to a maximum allowable fuel rate as a function of fuel tank ullage. 5. The dispenser of any preceding claim, wherein the control system regulates the fuel flow rate to a predefined average desired flow rate during a select portion of the fuelling operation based on the at least one parameter received from the vehicle. 6. The dispenser of claim 5, wherein the control system determines an amount of fuel required to fill the vehicle's tank based on the parameters received from the vehicle, determines a fuelling schedule to provide the predefined fuel flow rate and regulates the fuel flow rate throughout the select portion of the fuelling operation to provide an average fuel flow rate equal to the predefined average desired flow rate. 7. The dispenser of any preceding claim, wherein the control system ramps up the desired flow rate at the beginning of the fuelling operation to the maximum allowable fuel flow rate based on the at least one fuelling parameter received from the vehicle. 8. The dispenser of any preceding claim, wherein the control system ramps down the desired flow rate at the end of the fuelling operation from the maximum allowable fuel flow rate based on the at least one fuelling parameter received from the vehicle. 9. The dispenser of any preceding claim, wherein the control system continuously adjusts fuel flow rate to a maximum allowable fuel flow rate as a function of fuel tank ullage. 10. The dispenser of any preceding claim, further comprising a control valve in the fuel delivery path and the control system being operatively associated with the control valve for regulating the rate of flow in the fuel dehvery path during a portion of a fuelling operation. 11. The dispenser of any preceding claim, further comprising a flow transducer in the fuel delivery path configured to provide a flow transducer signal representing a volume of fuel flow in the fuel delivery path to the control system. 12. The dispenser of claim 11, wherein the control system is adapted to derive a forcing function from differences between an actual flow rate determined from the flow transducer signal and a desired flow rate, and the control system regulates the rate of flow in the fuel delivery path according to the forcing function. 13. The dispenser of any preceding claim, wherein the control system has a reference flow rate representing a desired flow rate and the control system is adapted to regulate the rate of flow in the fuel delivery path to achieve the reference flow rate. 14. The dispenser of any preceding claim, wherein the control system is configured to control the rate of flow in the delivery path to provide a predetermined desired rate of flow under varying dynamic conditions. 15. The dispenser of any preceding claim, wherein the control system is configured to control the rate of flow in the delivery path to provide a reduced rate of flow after a premature automatic shut-off. 16. The dispenser of any preceding claim, wherein the control system is configured to control the rate of flow in the delivery path to assist in topping off a fuelling operation. 17. The dispenser of any preceding claim, wherein the control system is configured to control the rate of flow in the delivery path to provide a reduced rate of flow when a predetermined number of automatic shut-offs occur. 18. The dispenser of any preceding claim, wherein the control system is configured to control the rate of flow in the delivery path to provide a reduced rate of flow when a predetermined number of automatic shut-offs occur within a predetermined period of time. 19. The dispenser of any preceding claim, wherein the control system is configured to control the rate of flow in the dehvery path to compensate for deteriorating components which affect the flow rate. 20. The dispenser of any preceding claim, wherein the control system is configured to indicate when a desired rate of flow is not achievable. 21. The dispenser of any preceding claim, wherein the control system is configured to indicate when a filter needs to be replaced, a delivery hose is deformed or the delivery path is otherwise obstructed. 22. The dispenser of any preceding claim, further comprising a vapour recovery system operatively associated with the control system and the dispenser further receives information relating to the presence of an onboard vapour recovery system on the vehicle, the control system being adapted to control the vapour recovery system according to the information relating to the presence of an onboard vapour recovery system. 23. The dispenser of any preceding claim, wherein the control system interrogates a vehicle transponder for the fuelling parameters. 24. A method of controlling fuel delivery comprising: providing a fuel dispenser having a receiver adapted to receive fuelling parameters from a vehicle; receiving the fuelling parameters from the vehicle at a fuel dispenser during a fuelling operation; initializing the fuel dispenser for fuel delivery; controlling fuel delivery to the vehicle based on the received fuelling parameters; and adjusting fuel dehvery rate during the fuelling operation so that a desired flow rate is not exceeded.

Inventors: BAKER WALTER L, HARTSELL HAL C, PAYNE EDWARD A, BAKER, WALTER, L., HARTSELL, HAL, C., PAYNE, EDWARD, A.
Applicants: GILBARCO LTD, GILBARCO LTD.
Application year: 1998
Main classification: B67D5
IPC codes: B67D5