Tamper-proof RFID reader for fuel dispensing nozzle and method of detecting tampering with an RFID reader

Abstract

An RFID reader (10) is mounted to a device including at least one metal part, such as a fuel dispensing nozzle (12) of a fuel management system (100). Due to the mounting to the device, an inductance of an RFID antenna (20) of the RFID reader (10) decreases, resulting in an increase in the capacitance of a variable capacitance element (22) that is adjusted by a controller (24) of the RFID reader (10) to tune the circuit of the RFID reader (10). When the RFID reader (10) is removed from the device, this results in a decrease of the capacitance of the variable capacitance element (22). This decrease can be determined, and a message indicating that the RFID reader (10) has been tampered with can be generated.

Description

DescriptionTAMPER-PROOF RFID READER FOR FUEL DISPENSING NOZZLE AND METHOD OF DETECTING TAMPERING WITH AN RFID READERTechnical Field

[0001] The present disclosure generally relates to the field of fuel management systems, in particular, to a tamper-proof radio-frequency identification (RFID) reader for a fuel dispensing nozzle, and a method of detecting tampering with an RFID reader.Background

[0002] Fuel Management Systems (FMS) are used to control and monitor the distribution of fuel. FMS may, for example, be used to authorize dedicated vehicles to dispense fuel from dedicated fueling stations, and to monitor the costs incurred for such authorized fuel dispensing processes. FMS make it possible to avoid misallocation or theft, and to precisely monitor the fuel bum of a vehicle fleet.

[0003] Known FMS include RFID readers, RFID tags and a controller.The RFID readers are positioned on a fuel dispensing nozzle. Such RFID readers communicate with RFID tags located on a vehicle to be fueled. Further, such RFID readers communicate with the controller of the FMS, which stores and processes the data provided by the RFID reader in order to control processes such as the fuel dispensing process for the vehicle to be fueled.

[0004] The present disclosure is directed, at least in part, to improving or overcoming one or more aspects of prior systems.Summary of the Disclosure

[0005] According to a first aspect, the present disclosure relates to a tamper-proof RFID reader for a fuel dispensing nozzle. The RFID reader has a housing, a mounting part configured to mount the RFID reader to the fuel dispensing nozzle, an RFID communication circuit accommodated in the housing, the RFID communication circuit including an RFID antenna and a variable capacitance element, and a controller configured to perform RFID communications via the RFID communication circuit at a predetermined operation frequency, and to tune the RFID communication circuit to the predetermined operation frequency by adjusting a capacitance of the variable capacitance element. The controller is further configured to monitor the capacitance of the variable capacitance element, determine an initial increase in the capacitance of the variable capacitance element, and store the capacitance after the initial increase as an initial value. The controller is configured to compare a current value of the capacitance of the variable capacitance element to the initial value, and determine that the RFID reader has been tampered with when the current value falls below the initial value by a predetermined amount or more.

[0006] According to a second aspect, a fuel management system has at least one fuel dispensing nozzle, at least one RFID reader according to the first aspect mounted to the at least one fuel dispensing nozzle, the RFID reader having a wireless communication module connected to the controller, wherein the controller is configured to transmit a message indicating that the RFID reader has been tampered with to an external data processing device, optionally together with a unique identifier associated with the RFID reader, and the central data processing device in communication with the at least one RFID reader. The central data processing device is configured to control a fuel dispensing unit associated with the at least one fuel dispensing nozzle to dispense fuel in response to a message received from the at least one RFID reader, and to disabledispensing of fuel via the at least one fuel dispensing nozzle after receiving a message indicating that the RFID reader has been tampered with from the RFID reader.

[0007] According to a third aspect, the present disclosure relates to a method of detecting tampering with an RFID reader mounted to a device. The device includes at least one metal part. The RFID reader includes an RFID communication circuit. The RFID communication circuit includes an RFID antenna and a variable capacitance element. The RFID reader includes a controller configured to perform RFID communications via the RFID communication circuit at a predetermined operation frequency, and to tune the RFID communication circuit to the predetermined operation frequency by adjusting a capacitance of the variable capacitance element. The method includes monitoring the capacitance of the variable capacitance element, determining an initial increase in the capacitance of the variable capacitance element, storing the capacitance after the initial increase as an initial value, comparing a current value of the capacitance of the variable capacitance element to the initial value, and determining that the device has been tampered with when the current value falls below the initial value by a predetermined amount or more.

[0008] Other features and aspects of this disclosure will be apparent from the following description and the accompanying drawings.Brief Description of the Drawings

[0009] Fig. 1 shows a schematic overview of a fuel management system in accordance with the present disclosure,Fig. 2 shows a perspective view of an exemplary RFID reader mounted to a fuel dispensing nozzle in accordance with the present disclosure, Fig. 3 shows an exemplary circuit diagram of an internal circuitry of the RFID reader in accordance with the present disclosure, andFig. 4 illustrates a graph showing a relationship between a capacitance of a variable capacitance element and a current flowing in a circuit of the RFID reader in accordance with the present disclosure.Detailed Description

[0010] The exemplary embodiments described herein are intended to teach the principles of the present disclosure, enabling those of ordinary skill in the art to implement and use the present disclosure in many different environments and for many different applications. Therefore, the exemplary embodiments are not intended to be, and should not be considered as, a limiting description of the scope of protection. Rather, the scope of protection shall be defined by the appended claims.

[0011] The present disclosure is based at least in part on the realization that, in a fuel management system including one or more fuel dispensing nozzles, to which an associated RFID reader is mounted, it is desirable to be able to detect tampering with the fuel management system, in particular, by removing the RFID reader from its associated fuel dispensing nozzle. The reason for this is that, when the RFID reader is removed from its associated fuel dispensing nozzle, the RFID reader can be presented to an RFID tag mounted on an authorized vehicle, resulting in a dispensing of fuel via the fuel dispensing nozzle, while the fuel dispensing nozzle can be inserted into, for example, a fueling port of a fuel tank of an unauthorized vehicle or container.

[0012] In accordance with the present disclosure, it has been realized that the RFID auto-tune circuitry of the RFID reader can be used in an advantageous manner to detect removal of the RFID reader from its associated fuel dispensing nozzle. Generally, the RFID auto-tune circuitry, in combination with an appropriate firmware installed on a controller of the RFID reader, is used to try and keep the RFID circuit including the RFID antenna and a variable capacitance resonant at the frequency the reader operates (i.e., to tune the RFID circuit to theoperating frequency), for example, 125 kHz, in order to optimize the tag reading range.

[0013] For example, the RFID driver circuit may include a bank of parallel capacitors, each capacitor being able to be switched into or out of operation using a switch controlled by the RFID controller. This results in an adjustable capacitance, which can have a large number of effective capacitance values. Accordingly, the adjustable capacitance allows changing the capacitance within the resonant RLC circuit of the RFID reader to compensate for a change in inductance in order to maintain resonance.

[0014] The circuit of the RFID reader may use a current sensor IC to determine the resonance. The adjustable capacitance can be intelligently switched while searching for a peak current consumption while driving the circuit at a set frequency of, for example, 125 kHz. In this manner, the peak current, which corresponds to the circuit resonance, is associated with an optimum configuration of the plurality of capacitors.

[0015] Generally, the present disclosure is based on the realization that the reason for the necessary adjustment of the capacitance is the change in the inductance of the circuit depending on the environment in which the RFID reader operates. In particular, this change occurs when the antenna of the RFID reader gets exposed to varying amounts of metal in the environment of the RFID reader.

[0016] Accordingly, it has been realized that, initially, when the RFID reader is installed on a fuel dispensing nozzle made of metal, this results in a decrease of the inductance of the antenna. In order to adjust to this change, and maintain resonance, the controller of the RFID reader sweeps through a range of capacitance values to find the resonant point. As the inductance had previously decreased, the circuit would tune with a higher capacitance value. This happens once after installing the RFID reader on the fuel nozzle.

[0017] During regular operation, when a fueling transaction takes place, the nozzle’s spout is placed in a fuel filler pipe of a vehicle. This exposes theantenna of the RFID reader to even more metal. Accordingly, the controller of the RFID reader will compensate in the same way as described above, by increasing the capacitance to maintain resonance.

[0018] It has been realized that the increase in the capacitance due to installing the RFID reader on the nozzle happens once during initial installation. As such, the capacitance after installing the RFID reader to the fuel nozzle has the lowest value that it can attain during normal operation. Accordingly, throughout the expected operation, the RFID reader is exposed to varying amounts of metal, and the capacitance value will increase, with its minimum value being determined by the fuel dispensing nozzle to which the RFID reader is mounted.

[0019] If the RFID reader is removed from the nozzle and no longer exposed to any metal in close proximity to the same, the inductance of the circuit will rise to a level higher than expected. This in turn will result in a capacitance value required for resonance, which will be lower than expected. In this manner, the unexpected drop or decrease of the capacitance can be detected, and it can be determined that the RFID reader has been tampered with, i.e., has been removed from the fuel dispensing nozzle. After removal of the RFID reader has been detected, there are several possibilities for reacting to the tampering, which will be described in more detail in the following.

[0020] Fig. 1 shows a schematic overview of an exemplary fuel management system 100 in accordance with the present disclosure. As shown in Fig. 1, fuel management system 100 includes a fuel dispensing unit 104, and at least one fuel dispensing nozzle 12 associated with fuel dispensing unit 104. Fuel management system 100 further includes at least one RFID reader 10 mounted to the at least one fuel dispensing nozzle 12. RFID reader 10 is configured to communicate with an RFID tag 106 mounted to a fuel filler pipe 108 of an exemplary vehicle 110. When fuel dispensing nozzle 12 is inserted into fuel filler pipe 108, RFID reader 10 is in close proximity to RFID tag 106.

[0021] Fuel management system 100 further includes a wireless controller 114 configured to communicate with RFID reader 10 and, optionally, a vehicle unit 112 mounted on vehicle 110. Further, wireless controller 114 is also in communication with a central data processing device 102 of fuel management system 100, and transmits messages received from RFID reader 10 and, optionally, vehicle unit 112 to data processing device 102. For example, wireless controller 114 may be mounted to a wall of a building adjacent to fuel dispensing unit 104. Here, it will be appreciated that the communication between wireless controller 114 and central data processing device 102 can be any appropriate type of communication, for example, wireless or wired communications, over the internet or in a local network, such that central data processing device 102 can be located at any desired location.

[0022] During operation, fuel dispensing nozzle 12 may be automatically activated, for example, using a motion sensor or the like, when a user picks up the same. After insertion of fuel dispensing nozzle 12 into fuel filler pipe 108 of vehicle 110, RFID reader 10 is used to read a vehicle ID, and potentially also a required fuel type from RFID tag 106. In some embodiments, the fuel type could also be stored in central data processing device 102 in association with the vehicle ID. RFID reader 10 may then communicate this information to wireless controller 114, for example, using an encrypted channel. Wireless controller 114 forwards the information to central data processing device 102, and central data processing device 102 may then allow or deny fueling based on information stored, for example, in a data base associated with central data processing device 102. It will be readily appreciated that allowing fueling is achieved by sending appropriate messages to fuel dispensing unit 104. After fueling has been completed, fuel dispensing nozzle 12 is removed from vehicle 110, and this can be detected by RFID reader 10, which can send a corresponding message to central data processing device 102 via wireless controller 114. In response to this,central data processing device 102 will command fuel dispensing unit 104 to stop supplying fuel.

[0023] Fig. 2 shows an exemplary RFID reader 10 in accordance with the present disclosure mounted to fuel dispensing nozzle 12. As shown in Fig. 2, RFID reader 10 has a housing 14 and a mounting part 16 configured to mount RFID reader 10 (i.e., housing 14) to fuel dispensing nozzle 12. For example, mounting part 16 may include an opening that conforms to a diameter of the spout of fuel dispensing nozzle 12 such that RFID reader 10 can be easily mounted on fuel dispensing nozzle 12 by inserting the spout of fuel dispensing nozzle 12 into the corresponding opening, and fixing RFID reader 10 to fuel dispensing nozzle 12 in this state, for example, using adjustable clamps or rings. It should be readily appreciated that RFID reader 10, in particular, housing 14 and mounting part 16, can have any appropriate configuration, as long as the configuration allows for mounting and fixing RFID reader 10 to fuel dispensing nozzle 12, preferably, various types of fuel dispensing nozzles 12.

[0024] Fig. 3 shows a circuit diagram of RFID reader 10 in accordance with the present disclosure. As shown in Fig. 3, RFID reader 10 includes an RFID communication circuit 18 accommodated in housing 14. RFID communication circuit 18 includes an RFID antenna 20 and a variable capacitance element 22. RFID reader 10 further includes a controller 24 configured to perform RFID communications via RFID communication circuit 18 at a predetermined operation frequency. For example, a frequency that is used may be 125 kHz. Of course, it will be appreciated that any other appropriate frequency may be used for communicating between RFID communication circuit 18 and a further RFID circuit provided in RFID tags read by RFID reader 10. As initially mentioned, RFID communication circuit 18 is tuned by controller 24 to the predetermined operation frequency by adjusting a capacitance of variable capacitance element 22. This will be described in more detail in the following.

[0025] RFID antenna 20 may have any appropriate configuration, for example, an air core antenna, a ferrite core antenna, an SMD chip antenna, a PCB trace antenna or a wire whip antenna. Controller 24 may have any appropriate configuration, for example, as a microcontroller or the like, which includes a CPU, memory, and the like. Controller 24 is connected to RFID antenna 20 and configured to drive antenna 20 to perform RFID communications via a driver circuit 26 in a known manner. Although not shown, it will be readily appreciated that controller 24 is supplied with power by a battery or another power source that is included in RFID reader 10 and accommodated inside housing 14 of the same. It will also be appreciated that control routines performed by controller 24 are stored in a memory of controller 24 as computer-executable instructions, which, when executed by a processor of controller 24, cause said processor to perform the functions described in the present disclosure. For example, corresponding computer-executable instructions may be included in a firmware that is installed in controller 24. As will be described in more detail in the following, said firmware can also be updated in order to obtain the functions described herein.

[0026] As shown in Fig. 3, RFID reader 10 further includes a wireless communication module 42 connected to controller 24. Controller 24 is configured to transmit a message indicating, for example, that RFID reader 10 has been tampered with to central data processing device 102 via wireless controller 114 (see Fig. 1). Here, it will be appreciated that this message can be transmitted together with a unique identifier associated with RFID reader 10, such that it is possible to identify which RFID reader 10 has been tampered with, and take appropriate counter measures.

[0027] As previously mentioned, RFID communication circuit 18 is tuned to the predetermined operation frequency by controller 24 by adjusting a capacitance of variable capacitance element 22. In particular, controller 24 is configured to monitor the capacitance of variable capacitance element 22. Inother words, controller 24 is able to determine or derive a value of the current capacitance of variable capacitance element 22. As the configuration of variable capacitance element 22 is known, and controller 24 is used to adjust the capacitance of variable capacitance element 22 by sending appropriate control signals to the same, controller 24 can derive the current value of the capacitance at any given time. In this manner, the capacitance of variable capacitance element 22 can be monitored by controller 24 while the internal power source of RFID reader has sufficient power.

[0028] Prior to installation of RFID reader 10 to fuel dispensing nozzle 12, variable capacitance element 22 will have a first capacitance value that is obtained by tuning RFID communication circuit 18 to the predetermined operation frequency in the state in which RFID reader 10 is not mounted to fuel dispensing nozzle 12, and is also not proximate to other metallic objects that could result in a decrease of the inductance of RFID antenna 20, and therefore an increase in the capacitance of variable capacitance element 22.

[0029] When RFID reader 10 is mounted to fuel dispensing nozzle 12, this results in a decrease in the inductance of RFID antenna 20 due to the presence of the metallic parts of fuel dispensing nozzle 12. Accordingly, controller 24 will tune RFID communication circuit 18 to the predetermined operation frequency by adjusting the capacitance of variable capacitance element 22 such that the capacitance increases. As this increase is the first increase of the capacitance of the newly installed RFID reader 10, this increase can be considered as an initial increase, i.e., in increase after the manufactured RFID reader 10 has been shipped to and installed by a customer as part of fuel management system 100 (see Fig. 1).

[0030] Controller 24 is further configured to store the capacitance of variable capacitance element 22 after the initial increase as an initial value. Here, it will be appreciated that the initial value will be stored in a memory associated with controller 24. In this manner, after RFID reader 10 has been installed andmounted to fuel dispensing nozzle 12, a capacitance of variable capacitance element 22 can be compared to the stored initial value. In particular, controller 24 can compare a current value of the capacitance of variable capacitance element 22 to said initial value.

[0031] As initially described, when an unauthorized user removes RFID reader 10 from fuel dispensing nozzle 12, RFID antenna 20 is no longer in close proximity to a metal part. Accordingly, the inductance of RFID antenna 20 increases. As a result, during the next tuning cycle, controller 24 tunes RFID communication circuit 18 to the predetermined operation frequency by reducing the capacitance of variable capacitance element 22. In other words, the current value of the capacitance of variable capacitance element 22 falls below the initial value that was previously stored. Accordingly, controller 24 determines that RFID reader 10 has been tampered with. In particular, this determination can be made when a current value of the capacitance falls below the initial value by a predetermined amount or more.

[0032] In response to determining that RFID reader 10 has been tampered with, controller 24 can, for example, transmit an appropriate message to central data processing device 102, and appropriate counter measures can be taken. For example, central data processing device 102, which generally is configured to control fuel dispensing unit 104 associated with the at least one fuel dispensing nozzle 12 to dispense fuel in response to a message received from the at least one RFID reader 10, may disable dispensing of fuel via the at least one fuel dispensing nozzle 12 after receiving the message indicating that RFID reader 10 has been tampered with from RFID reader 10. In some embodiments, central data processing device may also generate an alarm, for example, notify an operator of system 100, or trigger a visual or audio alarm signal in the vicinity of fuel dispensing unit 104.

[0033] It will be appreciated that variable capacitance element 22 can have any appropriate configuration which allows controller 24 to adjust acapacitance of the same, for example, to a plurality of discrete values. Fig. 3 shows an exemplary configuration in which variable capacitance element 22 includes a plurality of capacitors 30A-30E. Each of the plurality of capacitors is configured to be selectively connected between RFID antenna 20 and a first node GND of RFID communication circuit 18. For example, first node GND may be a common ground of the internal circuits of RFID reader 10.

[0034] A plurality of switches 32A-32E are respectively associated with the plurality of capacitors 30A-30E, and controller 24 is configured to switch each of the plurality of switches 32A-32E between an on state and an off state to adjust a capacitance of variable capacitance element 22. For example, it will be readily appreciated by the skilled person that switches 30A-30E may be semiconductor switches such as transistors, and controller 24 can switch between the on state and the off state of each switch by supplying corresponding control signals to the gates of the respective transistors in a known manner.

[0035] In the example shown in Fig. 3, the plurality of capacitors 30A- 30E includes five capacitors. However, it will be appreciated that in other embodiments the number of capacitors may be three or four, or may be more than five. In any case, at least when the plurality of capacitors 30A-30E have mutually different capacitances, it will be appreciated that, for a given number n of capacitors, generally 2ndifferent capacitances can be realized by appropriate switching of switches 30A-30E by controller 24.

[0036] In order to perform the above-mentioned tuning of RFID communication circuit 18, said RFID communication circuit 18 further has a current detection element 28 such as a current sense IC connected in series with RFID antenna 20. Controller 24 is configured to tune RFID communication circuit 18 to the predetermined operation frequency by determining a maximum current value Imax via current detection element 28 when driving RFID communication circuit 18, via driver circuit 26, at the predetermined operation frequency.

[0037] Fig. 4 shows an exemplary graph illustrating a relationship between a capacitor configuration (i.e., capacitance) of variable capacitance element 22 and a current detected by current detection element 28. Generally, as shown in Fig. 4, the detected current will have a maximum at the value Imax, and any deviation from the capacitor configuration associated with said maximum value Imax will result in a decrease in the detected current, i.e., the RFID communication circuit being out of resonance.

[0038] As previously mentioned, controller 24 is configured to monitor the capacitance of variable capacitance element 22, and also determine a current value of the capacitance after performing the tuning of RFID communication circuit 18 to the predetermined operation frequency. It will be appreciated that this tuning can be performed at regular intervals of, for example, from 0.1 to 10 s, preferably from 1 to 5 s. It will also be appreciated that the method of determining the maximum current value Imax can be any appropriate method. For example, controller 24 could simply sweep through all possible capacitor configurations, and determine the maximum current value Imax in this manner.

[0039] Preferably, however, controller 24 is configured to tune RFID communication circuit 18 by determining a starting capacitance associated with a previously determined maximum current value Imax. In other words, during a next tuning cycle, controller 24 starts with the capacitance that was found to correspond to the maximum current value Imax in the previously tuning cycle. Starting from this, controller 24 may then stepwise increase and decrease the capacitance from the starting capacitance in a predetermined number of steps. For example, controller 24 may start with the previous capacitor configuration, and stepwise increase and decrease the capacitance by switching switches 32A-32E such that the capacitances that are closest to the previously set capacitance are tested to see whether there is a new maximum current value Imax’ (indicated in Fig. 4 by a dashed line). If a new maximum current value is found, the capacitance of variable capacitance element 22 is adjusted from the startingcapacitance to the capacitance associated with the new maximum current value Imax’.

[0040] As previously described, assuming that, when RFID reader 10 is mounted to fuel dispensing nozzle 12, variable capacitance element 22 has a capacitor configuration that is indicated, for example, as configuration 16 in Fig. 4, resulting in the maximum current value of Imax, removal of RFID reader 10 from fuel dispensing nozzle 12 would result in that controller 24 reduces the capacitance of variable capacitance element 22. For example, this reduced capacitance may correspond to the capacitance configuration 13 shown in Fig. 4, resulting in a new maximum current value Imax’ associated with said configuration. In this manner, removal of RFID reader 10 can be detected.

[0041] In particular, as mentioned above, it can be determined that RFID reader 10 has been tampered with when the current value of the capacitance falls below the initial value that is stored in controller 24 by a predetermined amount or more. Here, it will be appreciated that the predetermined amount can be set such that false detections are suppressed. In other words, the predetermined amount should not be too low, such that minor shifts of RFID reader 10 on fuel dispensing nozzle 12, or any external influences that only have a minor effect on RFID reader 10 do not result in that an incorrect determination is made that RFID reader 10 has been removed from fuel dispensing nozzle 12. For example, the predetermined amount may be between 1% and 10%, preferably, between 3% and 7% of the initial value that is determined when RFID reader 10 is mounted to fuel dispensing nozzle 12 for the first time.

[0042] In this respect, it will also be appreciated that controller 24 is advantageously configured to determine the initial increase in the capacitance of variable capacitance element 22 when the capacitance increases from a predetermined value by more than a predetermined initial increase amount. For example, the initial increase amount may be between 4% and 10% of the predetermined value. The predetermined value may be the initial capacitance ofvariable capacitance element 22 when RFID reader 10 is shipped, i.e., a factory default, or it may be a value that is set by controller 24 after shipping. By using the above-indicated threshold, a false detection of RFID reader 10 being mounted to fuel dispensing nozzle 12 can be avoided, for example, due to a (temporary) presence of a metal object in the vicinity of RFID reader 10, which results in only a small increase in the capacitance, and perhaps only for a short time.

[0043] In this respect, controller 24 can also be configured to determine the initial increase in the capacitance of variable capacitance element 22 when the increase is continuously determined for a predetermined determination time or more, for example, 10s to 15 min, preferably 30s to 5 min. In this manner, it can be assured that any fluctuations of the capacitance, for example, during installation of RFID reader 10 to fuel dispensing nozzle 12, do not result in an incorrect determination of the initial value. In other words, it can be assumed that, after the predetermined determination time, RFID reader 10 has been successfully mounted to fuel dispensing nozzle 12, such that there should not be any further fluctuations of the inductance of RFID antenna 20, and therefore of the capacitance of variable capacitance element 22. In this manner, the initial value of the capacitance that is stored is reliably determined.

[0044] In other embodiments, controller 24 can be configured to read a special RFID tag that is brought into proximity of RFID reader 10 after mounting of the same and includes a unique identifier. In response to receiving this unique identifier, controller 24 stores the current value of the capacitance as the initial value.

[0045] Alternatively, RFID reader 10 may also have an actuation element 40 (see Fig. 2) provided on housing 14 and configured to be actuated by an operator. Controller 24 may be configured to store the initial value when actuation element 40 is actuated by an operator for a first time. This actuation for a first time may be an actuation by the operator that installs RFID reader 10 to fuel dispensing nozzle 12, and the operator may actuate actuation element 40after successful installation. Also in this manner, the initial value can be reliably and accurately set. Of course, it will be appreciated that controller 24 is configured to only register the initial value when actuation element 40 is actuated for the first time after RFID reader 10 has been shipped (or after the same has been reset to factory defaults by an authorized operator, or after a firmware update has been installed).

[0046] It will be appreciated that, as previously described, RFID reader 10 may be shipped in a state in which, upon a first installation of RFID reader 10 to fuel dispensing nozzle 12, the above-described processing is performed, i.e. the initial increase in the capacitance is determined, and the capacitance of the initial increase is stored as the initial value. However, it should also be appreciated that the present disclosure can also be used to retrofit existing RFID readers having a variable capacitance element with this functionality, by performing a firmware update of the firmware of controller 24. After such a firmware update, the capacitance of variable capacitance element 22 may again be set to the factory default value, i.e., a value that is lower than the value when RFID reader 10 is mounted to fuel dispensing nozzle 12. However, during a subsequent tuning cycle, controller 24 will again increase the capacitance of variable capacitance element 22, such that also in this manner the initial value can be reliably determined and stored in controller 24. Here, it will be appreciated that a necessary firmware update can be performed in any appropriate manner, for example, using wireless communication circuit 42, which may receive corresponding instructions and data from central data processing device 102 via wireless controller 114. Details of such a firmware update are well-known to the skilled person and are omitted herein.

[0047] In the same manner, controller 24 may also be configured to store the initial value in response to a command received from the outside, for example, via wireless communication module 42. This command may instruct controller 24 to determine the current value of the capacitance as the initial valueand store the same, and / or may provide instructions to be stored in a memory of RFID reader 10 and causing controller 24 to perform any of the methods of detecting tampering disclosed herein.

[0048] As a further security measure, controller 24 may be configured to determine that RFID reader 10 has been tampered with when the current value of the capacitance remains at a constant value that is greater than the initial value. For example, if a unauthorized person were to remove RFID reader 10 from fuel dispensing nozzle 12, and place RFID reader 10 adjacent to another metal part, it may happen that a decrease of the capacitance below the initial value cannot be accurately determined. However, it is unlikely that the capacitance after removing RFID reader 10 and placing the same adjacent to another metal part has exactly the same value as the initial value when the RFID reader 10 is installed to the associated fuel dispensing nozzle 12. In other words, with this additional check, it can also be determined that a tampering has taken place. For example, when the constant value that is greater than the initial value is determined for a predetermined period of time of more than 15 min, preferably more than 30 min, it can be assumed that the increased capacitance is not due to fuel dispensing nozzle 12 being inserted into fuel filler pipe 108 of an authorized vehicle (see Fig. 1), but the presence of another metal part in proximity to the RFID reader 10 in order to avoid detection of removal of the same.

[0049] Here, it will be appreciated that, if fuel dispensing unit 104 also includes metal parts, it may be necessary to learn a value of the capacitance in the state in which fuel dispensing nozzle 12 is provided on fuel dispensing unit 104. For example, controller 24 can be configured to learn this value when a capacitance that remains at a constant value greater than the initial value is detected for a predetermined period of time for a first time, and also store this learned value in the memory of the same. In this manner, when RFID reader 10 is removed from fuel dispensing nozzle 12 and placed in a different environment, which also results in an increased capacitance, this increased capacitance can bedistinguished from the increased capacitance when fuel dispensing nozzle 12 is provided on fuel dispensing unit 104. In this manner, the security can be further increased.

[0050] In a further alternative, controller 24 may have a maximum expected capacitance value during normal operation stored in memory, and may compare the current capacitance value to the maximum expected capacitance value. When it is determined that the current capacitance value exceeds the maximum expected capacitance value, a determination that RFID reader 10 has been tampered with can also be made.

[0051] In some embodiments, controller 24 may be configured to modify the initial value stored in memory, for example, in response to a detection of a change in temperature. This is to account for changes in the inductance and the capacitance of RFID antenna 20 and variable capacitance element 22, respectively, with temperature. Here, it will be appreciated that RFID reader 10 may comprise a temperature sensor, and controller 24 may receive a temperature detection result from such a temperature sensor, or that controller 24 may receive the temperature detection result from the outside, for example, via wireless communication circuit 42. In both cases, controller 24 is configured to modify the stored initial value such that a drop in the capacitance due to removal of RFID sensor 10 from fuel dispensing nozzle 12 can be reliably determined.Industrial Applicability

[0052] With the above-explained configuration of RFID reader 10, it becomes possible to reliably detect tampering with RFID reader 10, in particular, by removing RFID reader 10 from fuel dispensing nozzle 12. In this manner, fraud can be detected in fuel management system 100 in a reliable manner.

[0053] It will be appreciated, however, that the method of detecting tampering disclosed herein is not limited to the case in which RFID reader 10 is mounted to a fuel dispensing nozzle 12 of fuel management system 100. It shouldbe readily appreciated that the above-described method can be employed whenever RFID reader 10 is mounted to a device that includes at least one metal part, and it should be detected that RFID reader 10 has been removed from said device. The only thing that is required is that RFID reader 10 includes RFID communication circuit 18, that RFID communication circuit 18 includes RFID antenna 20 and variable capacitance element 22, and that RFID reader 10 includes controller 24 configured to perform RFID communications via RFID communication circuit 18 at a predetermined operation frequency, and to tune RFID communication circuit 18 to the predetermined operation frequency by adjusting a capacitance of variable capacitance element 22.

[0054] Accordingly, a method disclosed herein generally includes the steps of monitoring the capacitance of variable capacitance element 22, determining an initial increase in the capacitance of variable capacitance element 22 when RFID reader 10 is mounted to a device, which device includes at least one metal part, storing the capacitance after the initial increase as an initial value, comparing a current value of the capacitance of variable capacitance element 22 to the initial value, and determining that the device has been tampered with when the current value falls below the initial value by a predetermined amount or more.

[0055] As also described above, it will be appreciated that the method disclosed herein can also be implemented by retrofitting or updating existing RFID readers or other devices with the described functionality, for example, by means of a firmware update or the like. As such, the present disclosure, in a further aspect, also relates to a computer-readable medium including computerexecutable instructions which, when executed by a controller of an RFID reader, cause the controller to perform the steps of the above-described methods.

[0056] Terms such as “about“, “around“, “approximately^ or “substantially” as used herein when referring to a measurable value such as a parameter, an amount, a temporal duration, and the like, are meant to encompass variations of ±10% or less, preferably ±5% or less, more preferably ±1% or less,and still more preferably ±0.1% or less of and from the specified value, insofar as such variations are appropriate to perform in the disclosed invention. It is to be understood that the value to which the modifier “about” refers is itself also specifically, and preferably, disclosed. The recitation of numerical ranges by endpoints includes all numbers and fractions subsumed within the respective ranges, as well as the recited endpoints.

[0057] It is explicitly stated that all features disclosed in the description and / or the claims are intended to be disclosed separately and independently from each other for the purpose of original disclosure as well as for the purpose of restricting the claimed invention independent of the composition of the features in the embodiments and / or the claims. It is explicitly stated that all value ranges or indications of groups of entities disclose every possible intermediate value or intermediate entity for the purpose of original disclosure as well as for the purpose of restricting the claimed invention, in particular as limits of value ranges.

Claims

Claims1. A tamper-proof RFID reader (10) for a fuel dispensing nozzle (12), the RFID reader (10) comprising:- a housing (14);- a mounting part (16) configured to mount the RFID reader (10) to the fuel dispensing nozzle (12);- an RFID communication circuit (18) accommodated in the housing (14), the RFID communication circuit (18) including an RFID antenna (20) and a variable capacitance element (22); and- a controller (24) configured to perform RFID communications via the RFID communication circuit (18) at a predetermined operation frequency, and to tune the RFID communication circuit (18) to the predetermined operation frequency by adjusting a capacitance of the variable capacitance element (22), wherein the controller (24) is further configured to:- monitor the capacitance of the variable capacitance element (22);- determine an initial increase in the capacitance of the variable capacitance element (22);- store the capacitance after the initial increase as an initial value;- compare a current value of the capacitance of the variable capacitance element (22) to the initial value; and- determine that the RFID reader (10) has been tampered with when the current value falls below the initial value by a predetermined amount or more.

2. The RFID reader according to claim 1, wherein the variable capacitance element (22) includes a plurality of capacitors (30A-30E), each of the plurality of capacitors being configured to be selectively connected between the RFID antenna (20) and a first node (GND) of the RFID communication circuit (18).

3. The RFID reader of claim 3, further comprising a plurality of switches (32A-32E) respectively associated with the plurality of capacitors (30A-30E), wherein the controller (24) is configured to switch each of the plurality of switches (32A-32E) between an on state and an off state to adjust the capacitance of the variable capacitance element (22).

4. The RFID reader of claim 2 or 3, wherein the plurality of capacitors (30A-30E) includes three or more, preferably five or more capacitors (30A-30E).

5. The RFID reader of any one of claims 2 to 4, wherein the plurality of capacitors (30A-30E) have mutually different capacitances.

6. The RFID reader of any one of claims 1 to 5, wherein the RFID communication circuit (18) further comprises a current detection element (28) connected in series with the RFID antenna (20), wherein the controller (24) is configured to tune the RFID communication circuit (18) to the predetermined operation frequency by determining a maximum current value (Imax) via the current detection element (28) when driving the RFID communication circuit (18) at the predetermined operation frequency.

7. The RFID reader of claim 6, wherein the controller (24) is configured to tune the RFID communication circuit (18) by determining a starting capacitance associated with a previously determined maximum current value,stepwise increasing and decreasing the capacitance from the starting capacitance in a predetermined number of steps, and, if a new maximum current value is found, adjusting the capacitance of the variable capacitance element (22) from the starting capacitance to the capacitance associated with the new maximum current value.

8. The RFID reader of any one of claims 1 to 7, wherein the predetermined amount is between 1% and 10%, preferably, between 3% and 7% of the initial value.

9. The RFID reader of any one of claims 1 to 8, wherein the controller (24) is configured to tune the communication circuit (18) and compare the current value of the capacitance of the variable capacitance element (22) to the initial value at regular intervals of, for example, from 0.1 to 10 s, preferably, from 1 to 5 s.

10. The RFID reader of any one of claims 1 to 9, wherein the controller is configured to determine the initial increase in the capacitance of the variable capacitance element (22) when the capacitance increases from a predetermined value by more than a predetermined initial increase amount, for example, between 4% and 10% of the predetermined value, and / or when the increase is continuously determined for a predetermined determination time or more, for example, 10 s to 15 min, preferably, 30 s to 5 min.

11. The RFID reader of any one of claims 1 to 9, wherein the controller (24) is configured to store the initial value when: an actuation element (40) provided on the housing (14) is actuated by an operator for a first time; or a unique identifier is received from an external RFID tag via the communication circuit (18), for example, for a first time.

12. The RFID reader of any one of claims 1 to 11, wherein the controller (24) is further configured to determine that the RFID reader has been tampered with when the current value of the capacitance remains at a constant value that is greater than the initial value and, optionally, different from a previously learned value for a predetermined period of time of more than 15 min, preferably, more than 30 min.

13. The RFID reader of any one of claims 1 to 12, wherein the controller (24) is further configured to modify the stored initial value based on a detected temperature.

14. The RFID reader of any one of claims 1 to 13, further comprising a wireless communication module (42) connected to the controller (24), wherein the controller (24) is configured to transmit a message indicating that the RFID reader (10) has been tampered with to an external data processing device (102), optionally, together with a unique identifier associated with the RFID reader (10).

15. A fuel management system (100) comprising: at least one fuel dispensing nozzle (12); at least one RFID reader (10) in accordance with claim 14 mounted to the at least one fuel dispensing nozzle (12); and a central data processing device (102) in communication with the at least one RFID reader (10), wherein the central data processing device is configured to control a fuel dispensing unit (104) associated with the at least one fuel dispensing nozzle (12) to dispense fuel in response to a message received from the at least one RFID reader (10), and to disable dispensing of fuel via the at least one fueldispensing nozzle (12) after receiving a message indicating that the RFID reader (10) has been tampered with from the RFID reader (10).

16. A method of detecting tampering with an RFID reader (10) mounted to a device (12), the device (12) including at least one metal part, the RFID reader (10) including an RFID communication circuit (18) including an RFID antenna (20) and a variable capacitance element (22), the RFID reader (10) including a controller (24) configured to perform RFID communications via the RFID communication circuit (18) at a predetermined operation frequency, and to tune the RFID communication circuit (18) to the predetermined operation frequency by adjusting a capacitance of the variable capacitance element (22), the method comprising: monitoring the capacitance of the variable capacitance element (22); determining an initial increase in the capacitance of the variable capacitance element (22) when the RFID reader (10) is mounted to the device (12); storing the capacitance after the initial increase as an initial value; comparing a current value of the capacitance of the variable capacitance element (22) to the initial value; and determining that the device (10) has been tampered with when the current value falls below the initial value by a predetermined amount or more.

17. A computer-readable medium comprising computerexecutable instructions which, when executed by a controller (24) of an RFID reader (10), cause the controller (24) to perform the steps of the method of claim 16.

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