METHOD FOR COMMUNICATION BETWEEN A FUELING DEVICE AND A VEHICLE

Description

[0001] The present invention relates to a method for communication between a refueling device and a vehicle and a system for communication between a refueling device and a vehicle. State of the art

[0002] When refueling trucks with hydrogen, SAE J2799 requires a constant, relatively low hydrogen pressure to be used at the refueling device to avoid damage to the tank being filled. To this end, the current internal pressure of the hydrogen tank is sent to the refueling device prior to refueling. This communication can take place via an infrared interface (irDA). Using the transmitted internal pressure and the outside temperature determined by the refueling device, a safe pressure increase and a safe target value for the internal pressure of the tank are determined according to SAE J2799. The refueling device then refuels the hydrogen tank using these parameters. The use of irDA makes communication between the refueling device and the hydrogen tank prone to errors, as the infrared component of sunlight alone could be sufficient to disrupt communication.Scratches on the transmit and receive optics, as well as ice formation around a fueling nozzle or nozzle, can also have a disruptive effect. As a result, parameters cannot be exchanged, and the refueling process takes place at very low hydrogen pressure, making the refueling process lengthy.

[0003] To optimize the refueling process, especially to shorten refueling times, methods are known in which the vehicle and the refueling device are in signal communication and dynamically adjust a maximum, safe hydrogen pressure for refueling at any time. This requires interference-free communication technology. In addition to interference-free communication, unambiguous assignment of communication partners is a challenge, especially at filling stations with multiple refueling stations and a higher refueling frequency.

[0004] US Patent No. 9,022,080 B2 proposes solving this assignment problem by correlating a mass flow of hydrogen into the tank and a corresponding increase in pressure in the tank. To do this, the refueling device briefly changes the mass flow at a specific time and monitors the pressure in the tank, which is transmitted via a radio link. This allows for a correlation and, consequently, a clear assignment of the radio communication partners. Disclosure of the invention

[0005] It is therefore the object of the invention to achieve a secure communication connection between a refueling device and a vehicle, whereby the communication partners are always clearly assigned.

[0006] This is achieved by a method having the features of independent claim 1. Advantageous embodiments and further developments can be found in the subclaims and the following description.

[0007] A method for communication between a refueling device and a vehicle is proposed, comprising the steps of coupling the refueling device and a tank of the vehicle by means of a fuel nozzle, providing a pressurized fuel at the fuel nozzle, varying the pressure at the fuel nozzle by superimposing a predetermined base pressure with a pressure sequence for modulating a first signal to be transmitted, and detecting the pressure applied to the fuel nozzle by the vehicle and extracting the first signal to be transmitted from the detected pressure.

[0008] A core aspect of the invention is that the transmission of a first signal from the refueling device to the vehicle occurs by modulating a discharge pressure. This allows targeted data to be sent from the refueling device to the vehicle being refueled, independent of a wireless infrastructure and independent of a sometimes error-prone IrDA process. A prerequisite for implementing the method is the ability to specifically change the pressure at the refueling device in as discrete a manner as possible, so that a pressure sequence is modulated in a clearly recognizable manner and can be extracted by demodulation on the vehicle to obtain the underlying first signal.

[0009] The refueling system and the tank are coupled by mechanically connecting the fuel nozzle to a fuel inlet on the vehicle. The refueling process can begin immediately after the coupling process. For example, the coupling could be followed by the activation of an activation switch, which initiates the refueling process.

[0010] The refueling device is designed to deliver the fuel to the fuel nozzle under pressure. For this purpose, the refueling device can have a pump that conveys the fuel from a reservoir to the fuel nozzle. Various pump variants are possible, and the invention is not limited to a specific pump design; rather, all suitable pumps and pump-containing arrangements are explicitly encompassed.

[0011] To change the pressure at the fuel nozzle, it is conceivable that the aforementioned pump provides the base pressure. The pump could be coupled to a valve arrangement arranged downstream of the pump. The valve arrangement could include a pressure reducing valve or a pressure regulating valve arrangement. It is conceivable that a rapid pressure change at the fuel nozzle could be achieved by switching at least one valve. However, the pump could also be designed to implement rapid pressure changes directly. The pressure sequence that is modulated onto the base pressure does not necessarily have to include additional pressure, but could also be implemented in the form of a selective pressure reduction.

[0012] The vehicle in which the tank to be filled is located has at least one tank pressure sensor designed to detect a pressure inside the tank. This pressure also depends on the pressure at the fuel nozzle. If the pressure of the fuel in the fuel nozzle changes, this can consequently also be detected by the tank pressure sensor. The vehicle could have a control unit connected to the tank pressure sensor. The detected internal pressures could then be continuously recorded, at least temporarily, in the control unit. This results in an internal pressure curve or an internal pressure profile over time. By filtering, depending on the modulation method used, the pressure sequence can be extracted from the recorded pressure profile. This enables at least unidirectional transmission of a first signal from the refueling device to the vehicle.

[0013] Modulation could be achieved using pulse-width modulation (PWM), for example, although other modulation techniques already known from other areas are also conceivable. The base pressure in the system does not have to be kept stable over time, but could also rise or fall.

[0014] It is also conceivable that the vehicle is designed to detect pressure at the fuel tank nozzle even when no fuel is flowing. This allows the vehicle to detect an initial signal at the fuel tank nozzle, for example, before a fuel valve is opened.

[0015] This type of communication eliminates the susceptibility to errors, particularly with IrDA, due to external influences and, moreover, only uses hardware components already located in tanks and pumps. Furthermore, the method also offers significant advantages over wireless technologies used as alternatives to IrDA, since the previously described assignment problem does not occur when communicating using the method according to the invention. It would be conceivable to also use the method according to the invention to assign communication partners, in order to subsequently use a wireless connection between the identified communication partners.

[0016] In an advantageous embodiment, the vehicle further comprises varying a mass flow taken from the vehicle by superimposing a mass flow sequence on a predetermined base mass flow to modulate a second signal to be transmitted, and detecting the mass flow flowing through the fuel nozzle by the refueling device and extracting the second signal to be transmitted from the detected mass flow. Analogous to the previously described concept of transmitting a first signal from the refueling device to the vehicle, a second signal can also be transmitted from the vehicle to the refueling device by influencing the mass flow. The method thus allows bidirectional communication between the refueling device and the vehicle. A tank valve or tank valve arrangement could be provided on the vehicle side to influence the mass flow.To measure the mass flow, the refueling system can have a mass flow sensor that can be coupled to a control unit. The measured mass flows could then be continuously recorded, at least temporarily, in the control unit. This results in a mass flow curve or a mass flow progression over time. By filtering, the mass flow sequence can be extracted from the recorded mass flow progression. The mass flow, like the pressure, does not have to be constant, but can increase or decrease over time.

[0017] In a further advantageous embodiment, the method further comprises exchanging identification features of the refueling device and the vehicle or a cryptographic key, and establishing a radio connection between the refueling device and the vehicle using the identification features or the cryptographic key. Accordingly, in this embodiment, the method according to the invention is primarily used to initiate a secure and unambiguous radio connection. The method allows for highly reliable assignment of the communication partners for the radio connection.

[0018] In an advantageous embodiment of the method, the base pressure increases or decreases over time. With a fueling control system, the base pressure can be adjusted during fueling depending on the outside temperature and / or tank pressure.

[0019] The pressure sequence could also be based on a square, sine, or sawtooth signal, with the amplitude of the square, sine, or sawtooth signal falling below the base pressure. The pressure sequence could also deviate slightly from the square, sine, or sawtooth signal, since although the pressure change is initiated with such a signal, depending on the pump design or an associated valve arrangement, the pressure change does not occur immediately but with a certain inertia. This is taken into account by the term "based." In addition to amplitude modulation, frequency modulation can also be considered.

[0020] The method may further comprise initiating a refueling process with a predetermined safe minimum pressure as the base pressure, after which the pressure is varied. The safe minimum pressure could be selected such that all conceivable tanks refueled by the refueling device are refueled at a safe pressure at which damage to the tank is excluded.

[0021] Particularly preferably, the method further comprises regulating the pressure at the refueling device for accelerated refueling based on a pressure request from the vehicle transmitted via the second signal. This could allow the current tank pressure, a desired pressure at the fuel nozzle, or other parameters to be transmitted before, during, and / or after a refueling process.

[0022] Analogously, the invention relates to a system for communication between a refueling device and a vehicle, wherein the refueling device has a fuel nozzle that can be coupled to a tank of the vehicle, wherein the refueling device is designed to provide a fuel pressurized with a variable pressure through the fuel nozzle, wherein the refueling device has a first control unit that is designed to cause the pressure at the fuel nozzle to vary by superimposing a predetermined base pressure with a pressure sequence for modulating a first signal to be transmitted, wherein the vehicle has a second control unit that is designed to detect the pressure applied to the fuel nozzle via a tank pressure sensor and to extract the first signal to be transmitted from the detected pressure.

[0023] In an advantageous embodiment, the second control unit is designed to vary a mass flow by means of a tank valve by superimposing a predetermined base mass flow with a mass flow sequence for modulating a second signal to be transmitted, and wherein the first control unit is designed to detect the mass flow flowing through the tank nozzle via a mass flow sensor and to extract the second signal to be transmitted from the detected mass flow.

[0024] Particularly preferably, the refueling device is a hydrogen refueling device.

[0025] Further measures improving the invention are presented in more detail below together with the description of the preferred embodiments of the invention with reference to figures. Examples of implementation

[0026] It shows: Figure 1a refueling facility and a vehicle that form a communication system. Figure 2 a pressure curve at the fuel nozzle. Figure 3 a gas station. Figure 4 a schematic representation of the method according to the invention.

[0027] Fig. 1 shows a refueling device 2 and a vehicle 4 having a tank 6 to be filled by the refueling device 2. In this exemplary embodiment, the tank 6 is a hydrogen tank, and the refueling device 2 is a hydrogen refueling device. The refueling device 2 has a pump 8 connected to a hydrogen reservoir (not shown). The refueling device 2 can supply hydrogen to the tank 6 via a fuel nozzle 10.

[0028] The refueling device 2 has a first control unit 12 coupled to the pump 8. Thus, the refueling device 2 is configured to provide the hydrogen at a variable pressure in the fuel nozzle 10. The first control unit 12 is configured to cause the pressure at the fuel nozzle 10 to vary by superimposing a predetermined base pressure with a pressure sequence for modulating a first signal to be transmitted.

[0029] The vehicle 4 has a second control unit 14 connected to a tank pressure sensor 16. The second control unit 14 is configured to detect the pressure applied to the fuel nozzle 10 and to extract the first signal to be transmitted from the detected pressure.

[0030] The vehicle 4 can further comprise a tank valve 18, which is coupled to the second control unit 14 and is configured to regulate a mass flow entering the tank 6. The second control unit 14 is configured, for example, to vary the mass flow by means of the tank valve 18 by superimposing a mass flow sequence on a predetermined base mass flow to modulate a second signal to be transmitted. The first control unit 12 is coupled to a mass flow sensor 20, which is configured to detect the mass flow flowing through the fuel nozzle 10. The first control unit 12 can thus detect the mass flow via the mass flow sensor 20 and extract the second signal to be transmitted from the detected mass flow. Consequently, the refueling device 2 and the vehicle 4 can communicate via the hydrogen by specifically changing refueling features.

[0031] Fig. 2shows an example of a pressure curve that can be generated by the refueling device 2 for transmitting the first signal. Here, a base pressure 22 is shown, which increases continuously over time. However, it could also have a different curve and, for example, be constant, increasing and / or decreasing in certain areas and / or constant. A pressure sequence 24 in the form of a square wave signal is superimposed on the base pressure 22. This means that the pressure at the pump 8 is selectively increased in several intervals, so that the Fig. 2 The pressure curve shown is created. This is conceivable in the same way with the mass flow, which is influenced by vehicle 4, to transmit a second signal to the refueling device.

[0032] Fig. 3shows a gas station 26 with multiple refueling devices 2. Here, two vehicles 4 are each coupled to one of the refueling devices 2 via a fuel nozzle 10. By transmitting first and, if applicable, second signals, the vehicles 4 can receive cryptographic keys or identification features from the refueling devices 2, which they can use to establish a wireless radio connection with unambiguous assignment of the communication partners. This is useful for such gas stations 26 with adjacent refueling devices 2, since multiple vehicles 4 can each be within radio range of the refueling devices 2 and require unambiguous assignment for secure communication.

[0033] Fig. 4shows a schematic block view of the method according to the invention. The method comprises the steps of coupling 28 the refueling device 2 and the tank 6 of the vehicle 4 by means of a fuel nozzle 10, providing 30 a pressurized fuel at the fuel nozzle 10, varying 32 the pressure at the fuel nozzle 10 by superimposing a predetermined base pressure 22 with a pressure sequence 24 for modulating a first signal to be transmitted, and detecting 34 the pressure applied to the fuel nozzle by the vehicle 4 and extracting 36 the first signal to be transmitted from the detected pressure.

[0034] As explained above, the method may also comprise varying 38 a mass flow taken from the vehicle 4 by the vehicle 4 by superimposing a predetermined base mass flow with a mass flow sequence for modulating a second signal to be transmitted, and detecting 40 the mass flow flowing through the fuel nozzle 10 by the refueling device 2 and extracting 42 the second signal to be transmitted from the detected mass flow.

Claims

1. Method for communication between a fuelling device (2) and a vehicle (4), comprising the steps of: - coupling (28) the fuelling device (2) and a tank (6) of the vehicle (4) by means of a fuel nozzle (10), - providing (30) a pressurized fuel at the fuel nozzle (10), - varying (32) the pressure at the fuel nozzle (10) by superimposing a pressure sequence onto a specified base pressure (22) in order to modulate onto it a first signal to be transmitted, and - detecting (34) the pressure present at the fuel nozzle (10) by means of the vehicle (4) and extracting (36) the first signal to be transmitted from the detected pressure.

2. Method according to Claim 1, also comprising: - varying (38) a mass flow through the vehicle (4) taken from the vehicle (4) by superimposing a mass flow sequence onto a specified base mass flow in order to modulate onto it a second signal to be transmitted, and - detecting (40) the mass flow flowing through the fuel nozzle (10) by means of the fuelling device (2) and extracting the second signal to be transmitted from the detected mass flow.

3. Method according to Claim 1 or 2, also comprising - exchanging identification features of the fuelling device (2) and the vehicle (4) or a cryptographic key, and - establishing a radio link between the fuelling device (2) and the vehicle (4) using the identification features or the cryptographic key.

4. Method according to one of the preceding claims, wherein the base pressure (22) rises or falls over time.

5. Method according to one of the preceding claims, wherein the pressure sequence (24) is based on a rectangular, sinusoidal, or sawtooth signal, wherein an amplitude of the rectangular, sinusoidal, or sawtooth signal falls below the base pressure (22).

6. Method according to one of the preceding claims, also comprising initiating a fuelling operation at a predetermined secure minimum pressure as the base pressure (22), after which the varying (32) of the pressure occurs.

7. Method according to Claim 2, also comprising regulating the pressure at the fuelling device (2) for accelerated fuelling based on a pressure request by the vehicle (4) transmitted by means of the second signal.

8. System (5) for communication between a fuelling device (2) and a vehicle (4), wherein the fuelling device (2) comprises a fuel nozzle which can be coupled to a tank (6) of the vehicle (4), wherein the fuelling device (2) is designed to provide a fuel that has been subjected to a variable pressure through the fuel nozzle (10), wherein the fuelling device (2) comprises a first control unit (12), which is designed to cause varying (32) of the pressure at the fuel nozzle (10) by superimposing a pressure sequence (24) onto a specified base pressure (22) in order to modulate onto it a first signal to be transmitted, wherein the vehicle (4) comprises a second control unit (14), which is designed to detect by way of a tank pressure sensor (16) the pressure present at the fuel nozzle (10) and to extract the first signal to be transmitted from the detected pressure.

9. System (5) according to Claim 8, wherein the second control unit (14) is designed to vary, by means of a tank valve (18), a mass flow by superimposing a mass flow sequence onto a specified base mass flow in order to modulate onto it a second signal to be transmitted, and wherein the first control unit (12) is designed to detect by way of a mass flow sensor (20) the mass flow flowing through the fuel nozzle (10) and to extract the second signal to be transmitted from the detected mass flow.

10. System (5) according to Claim 8 or 9, wherein the fuelling device (2) is a hydrogen fuelling device.