Use of a tachograph to process recorded driving parameters of a vehicle

Abstract

Tachograph (10) for processing recorded driving parameters of a vehicle (1), comprising - an antenna input (10a) for connecting an external vehicle antenna (2), which is configured to provide GNSS signals as the respective antenna signal (A) to the antenna input (10a) when connected, and - a computing unit (11) which is configured to receive the respective antenna signal (A) and to evaluate the driving parameters recorded by the tachograph (10), characterized in that - the tachograph (10) includes at least one antenna output (10b) for connecting a respective external vehicle receiver unit (3), and - the tachograph (10) includes a splitter circuit (12) which couples the antenna input (10a) and the at least one antenna output (10b) for transmitting the respective provided antenna signal (A).

Description

[0001] The invention relates to a tachograph for processing vehicle parameters recorded by it. The invention further relates to a vehicle with a corresponding tachograph. The invention also relates to a method for processing vehicle parameters recorded by it from a vehicle with a tachograph.

[0002] A tachograph is an electronic device designed for installation in vehicles. It is used primarily to record the activity of drivers and vehicles in commercial and / or passenger transport. For example, it monitors driving and rest times. A tachograph is also known as a vehicle data recorder or EU control device.

[0003] The tachograph records driving parameters, for example, from associated vehicle systems, with the vehicle parameters indicating or containing the activity. Due to legal requirements, such as EU directives, the technical requirements for tachographs have increased in recent years. For example, the tachograph is now required to validate the recorded driving parameters, i.e., to check their accuracy. This is intended to effectively prevent manipulation of the recorded driving parameters.

[0004] For validation purposes, the tachograph can be coupled with an antenna to receive satellite signals. These satellite signals contain information such as the vehicle's position and / or time, which can be compared to the parameters recorded by the vehicle's systems for tamper protection. Preferably, the antenna is a GNSS antenna capable of receiving GNSS signals. GNSS stands for Global Navigation Satellite System. It is a system for determining position and navigating on Earth and in the air by receiving signals from navigation satellites.GNSS is a collective term for the use of existing or future global satellite systems such as GPS (Global Positioning System), GLONASS (global satellite navigation system), Galileo, or other well-known navigation systems.

[0005] The tachograph can be operated with an internal antenna. "Internal" here means that the antenna is, for example, integrated with the other components of the tachograph in a common housing. The use of an internal GNSS antenna in conjunction with a tachograph is known from the prior art.

[0006] From EP 3 213 115 B1 it has become known to authenticate a GNSS raw signal and to determine a position signal in a safe manner using this signal.

[0007] EP 3 370 087 A2 discloses an onboard unit for a motor vehicle with a GNSS antenna and a GNSS receiver for determining the vehicle's position. Depending on the availability, i.e., the signal quality, of several received GNSS signals, the receiver can decide which signal should be used to determine the position.

[0008] Depending on the tachograph's installation location in the vehicle, the reception of the internal antenna may be insufficient for its intended use. In this case, an external antenna, such as a vehicle antenna, can be used. The external antenna can also be used by other receiving devices, such as a vehicle navigation system.

[0009] EP 3 499 269 A1 describes a method for determining position using a first antenna, housed within a casing, for receiving satellite signals in the form of a first satellite signal, and a second antenna, located outside the casing, for receiving satellite signals in the form of a second satellite signal. A comparison of parameters from the two satellite signals provides insights into potential sources of interference with the proposed positioning arrangement.

[0010] If an external antenna is to be used for a tachograph and one or more other receivers in the vehicle, a so-called (antenna) splitter is used to split the antenna signal received by the external antenna. A disadvantage of using a splitter is that the tachograph is no longer able to directly diagnose the antenna. This means the tachograph cannot reliably detect whether the antenna is functioning correctly, which could indicate tampering. As a result, conventional tachographs, such as those installed in modern vehicles, require multiple antennas. This increases manufacturing costs and necessitates providing sufficient installation space.

[0011] The invention is based on the objective of providing a tachograph in the vehicle for processing recorded driving parameters in a cost-effective manner and with reduced installation space requirements.

[0012] This problem is solved by the subject matter of the independent patent claims. Advantageous embodiments and further developments of the invention are the subject matter of the dependent patent claims, the description, and the figures.

[0013] The invention is based on the finding that it is possible to use only one antenna in the vehicle, which the tachograph can directly diagnose, if the tachograph itself is equipped with a splitter function. This allows the tachograph to split or divide the antenna signal provided by the antenna. By connecting the antenna directly to the tachograph, the tachograph can reliably detect that the antenna is present and functional. This effectively prevents tampering, for example. The splitter function in the tachograph thus enables reliable antenna diagnostics and allows the driving parameters to be reliably processed and validated.

[0014] According to one aspect, the invention proposes a tachograph for processing recorded driving parameters of a vehicle. In this context, "processing" can mean validating the driving parameters. Additionally or alternatively, processing can mean utilizing or applying the driving parameters for other services within or for the vehicle. For example, the driving parameters can be used for fleet management.

[0015] The tachograph includes an antenna input for connecting an external vehicle antenna, which, when connected, is designed to provide GNSS signals as the respective antenna signal to the antenna input. That is, the vehicle antenna, which is preferably designed as a GNSS antenna, can transmit the respective antenna signal to the antenna input.

[0016] Furthermore, the tachograph includes a processing unit designed to receive the respective antenna signal and evaluate it to process the driving parameters recorded by the tachograph. This processing or evaluation is primarily intended to monitor or verify the driving parameters in order to prevent manipulation of the tachograph, particularly during the recording of driving parameters, and / or to detect antenna defects. To enable the processing unit to receive the antenna signal, it is coupled or connected to the antenna input.

[0017] Furthermore, the tachograph includes at least one antenna output for connecting an external vehicle receiving unit. This means the tachograph can have one or more antenna outputs. An external vehicle receiving unit can be connected to each of these antenna outputs. The receiving unit could be, for example, a GNSS receiver or a splitter for distributing antenna signals. For instance, the receiving unit could be a GNSS receiver integrated into the vehicle's navigation system.

[0018] To implement the splitter function, the tachograph also includes a splitter circuit. This circuit couples or connects the antenna input and at least one antenna output to transmit the antenna signal present at the input. It is therefore an electronic circuit that allows the antenna input to be connected internally to the processing unit and externally, via the antenna output, to the connected vehicle receiver. Using the splitter circuit, the antenna signal present or received at the antenna input can thus be transmitted or forwarded to the processing unit for processing and to the external vehicle receiver via the antenna output. This enables the distribution of the vehicle antenna signal across multiple channels within the tachograph.The splitter circuit can therefore be understood as a 2-way switch or, depending on the number of output connections, as a multi-way switch for antenna signal distribution.

[0019] Because the vehicle antenna is directly connected to the tachograph, the tachograph can directly diagnose the antenna's condition. Furthermore, by utilizing the splitter function provided by the splitter circuit, the tachograph can forward or transmit the received antenna signal to other receiving devices. This eliminates the need for a single antenna in the vehicle, which can be used by multiple devices. Overall, this reduces manufacturing costs and the required installation space.

[0020] The tachograph is preferably a digital tachograph. It can be designed as a speedometer with an integrated data recorder that records driving parameters for each journey (tachograph function). These driving parameters can include, for example, driving time (such as driving and rest times, breaks in driving time), additional kilometers driven, and speed. The recording of driving parameters with a tachograph is based on established measurement principles. For example, the parameters of the vehicle's systems, each responsible for determining, measuring, or executing the respective driving parameter, can be recorded. These vehicle systems can include, for example, the steering or braking system, the drive system, or the vehicle's navigation system.

[0021] In this context, an antenna signal is specifically an electrical signal generated by an antenna when exposed to a satellite signal (electromagnetic wave) as described above. The antenna thus acts as a transducer for an electromagnetic wave. The antenna signal is preferably a high-frequency or radio-frequency signal (RF signal). That is, the antenna signal is an alternating electrical signal with a frequency in the radio wave range.

[0022] The respective satellite signal, and consequently the antenna signal, can contain or encode position information that enables the vehicle's activity to be determined. This position information can include, for example, a satellite position and / or a time. Using established evaluation principles for satellite-based positioning, the processing unit can use this position information to determine the vehicle's activity parameters. For example, the processing unit can execute or apply known triangulation and / or trilateration methods. These activity parameters include, for example, the vehicle's position at specific times, allowing the determination of vehicle activity such as driving and rest times.

[0023] For validation, the activity parameters can be compared with the driving parameters using the processing unit to verify the correctness or accuracy of the driving parameters (validation function). For example, it is checked whether the activity parameters indicate the same vehicle activity as indicated by the driving parameters. If the vehicle activity information of the driving parameters matches the vehicle activity information of the activity parameters as intended, the driving parameters are validated and thus marked as correct. If, however, there is no match, the driving parameters are falsified. That is, the driving parameters are considered incorrect or falsified. This can happen, for example, if the driving parameters have been manipulated.

[0024] The antenna input and antenna output can each be understood as a connection or interface for connecting the vehicle antenna or the respective vehicle receiver unit. Each connection is suitable or designed for transmitting antenna signals. It could, for example, be a coaxial connection.

[0025] A computing unit can be understood, in particular, as a data processing device containing a processing circuit. The computing unit can therefore, in particular, process data to perform arithmetic operations. The computing unit can, in particular, contain one or more computers, one or more microcontrollers, and / or one or more integrated circuits, for example, one or more application-specific integrated circuits (ASICs), one or more field-programmable gate arrays (FPGAs), and / or one or more systems-on-a-chip (SoCs).The computing unit can also include one or more processors, for example, one or more microprocessors, one or more central processing units (CPUs), one or more graphics processing units (GPUs), and / or one or more signal processors, in particular one or more digital signal processors (DSPs). The computing unit can also include a physical or virtual array of computers or other units of the aforementioned type. The computing unit as a whole can be composed of several components, such as a receiver, an evaluation circuit, and security chips.

[0026] Preferably, the computing unit comprises one or more modules for various processing operations or functions. Each module can be implemented as a hardware and / or software module. For example, the computing unit for acquiring and processing driving parameters can include an evaluation module. This evaluation module can implement the tachograph's data recorder function. Furthermore, the computing unit can include a GNSS receiver module for acquiring and processing the respective antenna signal. This GNSS receiver module can be used to process and, in particular, validate the driving parameters.

[0027] The invention includes embodiments that offer additional advantages.

[0028] According to one embodiment, the splitter circuit includes a diagnostic unit configured to provide an internal diagnostic signal to the antenna input, i.e., to apply it to the antenna input. The diagnostic unit is configured to determine an antenna signal value from a resulting input signal at the antenna input, which comprises the antenna signal and the diagnostic signal. This value indicates the antenna status of the vehicle antenna. In other words, the aforementioned diagnostic capability for the vehicle antenna is implemented in the tachograph by means of the diagnostic unit.

[0029] In this context, a diagnostic signal refers to an electrical signal used by a receiving device to detect an antenna's status or condition. The antenna status indicates, for example, the antenna's availability and / or the signal strength. Thus, the antenna status provides information about whether the antenna is functioning correctly or even connected.

[0030] The diagnostic signal can be, for example, a DC electrical signal. For instance, the diagnostic signal can be provided as a DC voltage. When the diagnostic unit applies the diagnostic signal to the antenna input, the input signal can be tapped at the antenna input. The shape or parameters of this input signal depend on the antenna status. With a functioning antenna, the diagnostic signal and the antenna signal are superimposed to form the input signal. The diagnostic unit can detect this input signal and determine the antenna signal value. This antenna signal value can be, for example, a current value or current waveform of the input signal. The antenna signal value provides a parameter of the input signal that can be used as a measure of the antenna status.

[0031] According to one embodiment, the processing unit is configured to evaluate the antenna signal value according to a predefined evaluation criterion to determine the antenna status. This means that the processing unit verifies the antenna's proper functioning. To perform the evaluation, the processing unit can apply the evaluation criterion to the antenna signal value. Applying the evaluation criterion to the antenna signal value yields the antenna status.

[0032] In one embodiment, it is provided that the evaluation includes checking whether the antenna signal value deviates from a target value range specified according to the evaluation criterion, which the antenna signal value has when the vehicle antenna has a properly functioning antenna status.

[0033] This means that the evaluation criterion can implement an assignment rule with which the antenna signal value can be assigned to an antenna status.

[0034] According to the assignment rule, the target value range is specified, and the functional antenna status is assigned to this target value range. Value ranges outside the target value range are assigned a non-functional antenna status. Functional here means that the antenna is connected and the signal quality is sufficient or desired. Non-functional, on the other hand, means that the antenna is not connected or the signal quality is not sufficient or desired. The target value range and the signal quality can be determined, for example, by the vehicle antenna manufacturer or through tests or simulations.

[0035] If the vehicle antenna is in its intended, functioning state, the antenna signal value is within or within the specified range. The antenna signal value does not deviate from the specified range. If the vehicle antenna is in a non-functional state, the antenna signal value is outside the specified range and either exceeds or falls below it. The antenna signal value deviates from the specified range.

[0036] The deviation from the target value range therefore only occurs if the antenna is malfunctioning or defective, i.e., broken or, for example, not connected. A defective antenna can be measured as an electrical short circuit, where the antenna signal exhibits an essentially infinitely high current value. If the antenna is not connected, an electrical open circuit can be measured, where the antenna signal exhibits an essentially infinitely low current value.

[0037] According to one embodiment, the splitter circuit comprises a first decoupling unit configured to filter the internal diagnostic signal from the input signal for processing the vehicle parameters by the processing unit. The aim is to remove or block the diagnostic signal from the input signal for further processing. Only the antenna signal, i.e., the useful portion of the input signal, should be used for evaluating the vehicle parameters by the processing unit. In this context, the decoupling unit can be understood as a filter circuit with an electronic filter. For example, the filter circuit can include one or more electrical capacitors.

[0038] According to one embodiment, the splitter circuit has a second decoupling unit configured to filter an external diagnostic signal that the vehicle receiver provides at least one antenna output when connected for determining the antenna status of the vehicle antenna. This means that the vehicle receiver can also include such a diagnostic unit.

[0039] The second decoupling unit can be designed analogously to the first. This means the second decoupling unit can block or remove the external diagnostic signal from the vehicle receiver unit when it is transmitted to the splitter circuit. As a result, the external diagnostic signal is not forwarded via the splitter circuit in the tachograph to the antenna input and the vehicle antenna.

[0040] According to one embodiment, the splitter circuit includes an antenna simulation unit. When supplied with the external diagnostic signal, which the vehicle receiver provides in its connected state for determining the antenna status of the vehicle antenna with at least one antenna output, the antenna simulation unit is configured to specify or simulate the antenna status of the vehicle antenna for the vehicle receiver. The antenna simulation unit thus enables the function or characteristics of the vehicle antenna to be replicated during external diagnostics. This allows the vehicle receiver to perform its diagnostics in the desired or necessary manner to verify the presence and signal quality of the vehicle antenna.

[0041] According to one embodiment, the processing unit is configured to couple the antenna simulation unit to the at least one antenna output, depending on the result of the antenna signal evaluation, in order to specify the intended functional status of the vehicle antenna. That is, the processing unit can control the antenna simulation unit and thereby either disconnect or connect it to the antenna output. This ensures that when the tachograph is supplied with the external diagnostic signal, it correctly transmits the actual or measured functionality of the vehicle antenna to the vehicle receiver unit. Preferably, the antenna simulation unit is only connected to the antenna output if the vehicle antenna has been detected as functional.In contrast, the antenna simulation unit is preferably only disconnected from the antenna output when the vehicle antenna has been detected as malfunctioning.

[0042] To enable disconnection and connection, the antenna simulation unit is preferably designed to be switchable. For this purpose, the antenna simulation unit can be connected to the output terminal, for example, by means of a switching unit that can be controlled by the processing unit. By controlling the switching unit, the processing unit can switch the switching unit between at least two different switching states. In one switching state, the antenna simulation unit is connected to the output terminal, while in another switching state it is disconnected.

[0043] In the following, a switching unit can be understood in particular as an electronic switch. The switching unit can, for example, comprise one or more switching elements, which can be implemented as semiconductor switches. A transistor, such as a bipolar transistor or a field-effect transistor, in particular a MOSFET (metal-oxide-semiconductor field-effect transistor), or a thyristor, or a relay can be used as a semiconductor switch.

[0044] According to one embodiment, an alternative arrangement is provided for the diagnostic unit to supply the antenna signal value to the antenna simulation unit. The antenna simulation unit is configured to supply the antenna signal value to the vehicle receiver unit to specify the antenna status.

[0045] This means that the control signal does not come from the processing unit, but rather the output signal (antenna signal value) from the diagnostic unit is used to operate the antenna simulation unit. The antenna simulation unit's behavior is thus determined by the output signal of the diagnostic unit, and it transmits the respective antenna status. Preferably, the antenna signal value is also provided to the processing unit for evaluation.

[0046] According to one embodiment, the antenna simulation unit provides an electrical resistance. That is, the antenna simulation unit can act as a resistive load for the antenna output when connected. Alternatively, the antenna simulation unit can, for example, be configured as a current sink.

[0047] According to one embodiment, the splitter circuit includes an amplifier unit configured to amplify the antenna signal provided via the antenna input for delivery to the at least one output terminal. This ensures that the antenna signal has sufficient signal strength for further processing before being passed on or transmitted to the vehicle's receiving unit.

[0048] The amplifier circuit can include at least one amplifier suitable or designed for amplifying antenna signals. An amplifier can be an electronic assembly that processes an incoming signal such that the resulting output signal preferably has a different amplitude than the input signal. The amplification can be positive or negative, so that the signal amplitude or signal level is increased, particularly in magnitude, after amplification. Alternatively, a gain of one can be set. The amplifier can, for example, be a circuit with one or more operational amplifiers.

[0049] According to one embodiment, the tachograph includes an internal tachograph antenna configured to provide the GNSS signals as a further antenna signal to the processing unit for processing the driving parameters recorded by the tachograph. The tachograph also includes a switching unit which, in a first switching state, couples or connects the vehicle antenna to the processing unit via the antenna input. In a different second switching state, the switching unit couples or connects the tachograph antenna to the processing unit. The processing unit is configured to switch the switching unit to the first or second switching state depending on the respective antenna status of the antenna signal and the further antenna signal.

[0050] This means that the processing unit can determine the antenna status of the external vehicle antenna using the diagnostic unit. Based on this, the processing unit can control the switching unit to toggle between the respective switching states. Thus, depending on the signal quality or availability of the external vehicle antenna signal, either the internal or the external antenna can be used for processing.

[0051] In this context, "internal" means that the tachograph antenna is installed within the tachograph housing along with the other components. This means, for example, that the tachograph antenna may be mounted or attached to a shared circuit board with the processing unit.

[0052] The tachograph antenna can be designed analogously to the vehicle antenna. Particularly preferably, the tachograph antenna, when coupled or connected to the processing unit, is also connected or coupled to the antenna output. This coupling can be implemented using a splitter circuit. Thus, the additional antenna signal acquired or provided by the tachograph antenna can also be used for operating the external vehicle receiver unit in the manner described above. To achieve the desired signal amplification for further processing in the vehicle receiver unit, the tachograph antenna can, for example, include an amplifier unit as previously described.

[0053] According to one aspect, the invention also relates to a vehicle with a tachograph, such as the one described above by way of example. Furthermore, the vehicle comprises an external vehicle antenna and an external vehicle receiver unit, which are connected to the tachograph in the manner described above. "External" here means that the vehicle antennas and the vehicle receiver unit are installed externally, i.e., outside of the tachograph, within the vehicle.

[0054] The vehicle is preferably designed as a motor vehicle, in particular as a car and / or passenger car or truck or passenger bus or as a motorcycle.

[0055] According to one aspect, the invention also relates to a method for processing recorded driving parameters of a vehicle equipped with a tachograph. In this method, GNSS signals are received at an antenna input of the tachograph as the respective antenna signal from a connected external vehicle antenna. A processing unit of the tachograph receives the respective antenna signal and evaluates it for processing the driving parameters recorded by the tachograph. A splitter circuit of the tachograph couples the antenna input to at least one antenna output of the tachograph for connecting an external vehicle receiver. The splitter circuit then transmits the respective antenna signal from the antenna input to the at least one antenna output.

[0056] The procedure is therefore a method for operating a tachograph, as previously described as an example. The procedure can thus be carried out or performed using the tachograph. The tachograph executes or performs the procedure.

[0057] For use cases or application situations that may arise during the procedure and are not explicitly described here, it may be provided that an error message is issued and / or a default setting and / or a predetermined initial state is set according to the procedure.

[0058] The invention also includes further developments of the inventive method and the inventive vehicle, which have features already described in connection with the further developments of the inventive tachograph. For this reason, the corresponding further developments of the inventive tachograph are not described again here.

[0059] The invention also includes combinations of the features of the described embodiments.

[0060] An embodiment of the invention is described below. The following is shown: Fig. 1 a schematic representation of a vehicle with a tachograph for processing recorded driving parameters of the vehicle and Fig. 2 a schematic process flow diagram for a procedure for operating a corresponding tachograph.

[0061] The embodiment described below is a preferred embodiment of the invention. In this embodiment, the described components each represent individual features of the invention that can be considered independently of one another. Each of these features further develops the invention independently and can therefore be considered part of the invention individually or in a combination other than that shown. Furthermore, the described embodiment can also be supplemented by other features of the invention already described.

[0062] In the figures, functionally identical elements are each provided with the same reference symbols.

[0063] Fig. Figure 1 shows a schematic representation of a vehicle 1. Vehicle 1 is represented as an example of a truck. Vehicle 1 is equipped with a tachograph 10, also known as a tachograph or EC control device. Preferably, it is an intelligent or digital tachograph. For example, the DTCO ® used by the company VDO Fleet Services.

[0064] The tachograph 10 allows the use or activity of vehicle 1 to be controlled or monitored in a familiar manner. For example, driving and rest times, breaks in driving time, kilometers driven, speed, and / or the vehicle's weight can be recorded. This enables, for example, the recording of working time and weight for the transport of goods in the truck. The tachograph 10 is also suitable, for example, for determining position, in order to monitor border crossings with vehicle 1.

[0065] To monitor activity, the tachograph 10 records vehicle driving parameters. The tachograph 10 thus performs a tachograph function. The driving parameters can be determined by vehicle systems of vehicle 1 and provided to the tachograph 10 in a known manner. The vehicle systems that are in Fig. Items not shown in 1 may, for example, be components of a powertrain or a navigation system of the vehicle.

[0066] For certain functions or applications, such as position determination and / or processing the recorded driving parameters, for example for validation (validation function), the Tachograph 10 uses an antenna. A GNSS antenna, for example, is used to receive satellite or GNSS signals.

[0067] The Tachograph 10 can be operated with either an internal or an external antenna. Internal means that the antenna is housed or integrated within a casing 19 of the Tachograph 10. External means that the antenna is located outside the casing 19. It is possible that reception of satellite signals using the internal antenna may be too poor or impossible. Therefore, it is common practice to use both an internal and an external antenna with a Tachograph 10.

[0068] The external antenna can, for example, be a vehicle antenna 2, as used in Fig. Figure 1 is shown as an example. The vehicle antenna 2 is generally intended to be used in or on the vehicle 1 not only for the tachograph 10, but also for other receiving devices. This includes, for example, a vehicle receiving unit 3, which in the present embodiment is shown as a navigation device.

[0069] To supply multiple receivers, it is necessary to divide or split the antenna signal A provided by vehicle antenna 2. A splitter can be used for this purpose. The splitter is used as a two-way or multi-way switch. Since the tachograph 10 is intended to be able to directly diagnose vehicle antenna 2, it is not possible to connect the external vehicle antenna 2 to the tachograph 10 in conjunction with an external splitter. This is because the tachograph 10 must be able to perform a reliable diagnosis of vehicle antenna 2. Only in this way can it be reliably detected whether the driving parameters have been manipulated, resulting, for example, in incorrectly recorded driving and rest times, or whether vehicle antenna 2 is malfunctioning.

[0070] The tachograph 10 is therefore equipped with an internal splitter circuit 12, which performs the splitter function for distributing the antenna signal to one or more other terminal devices. The vehicle antenna 2 is thus directly connected to the tachograph 10.

[0071] The tachograph 10 includes an antenna input 10a for connecting the vehicle antenna 2. Furthermore, the tachograph 10 includes at least one antenna output 10b, to which another of the terminal devices that are to be supplied with the antenna signal A from the vehicle antenna 2 is connected. In the present embodiment, a tachograph 10 with exactly one antenna output 10b is shown. The vehicle receiver 3 is connected to the antenna output 10b.

[0072] The antenna input 10a is connected to a processing unit 11 of the tachograph 10 via the splitter circuit 12. The processing unit 11 performs the function of processing the driving parameters recorded by the tachograph 10 based on the antenna signal A provided by the vehicle antenna 2. In the present embodiment, the processing relates in particular to validating the driving parameters. However, other processing of the driving parameters can also take place in the processing unit 11. The processing unit is preferably an electronic data processing device. The processing unit 11 can, for example, comprise one or more microprocessors and / or one or more microcontrollers with which corresponding processing steps can be executed. The processing unit 11 can, for example, have several modules, each of which can perform different processing processes or functions.One module could be, for example, an evaluation module for recording and processing driving parameters. This evaluation module enables the tachograph function of the tachograph 10. Another module could be, for example, a GNSS receiver module, which can record and process the respective antenna signal A for validating the driving parameters. The individual modules can be implemented as hardware and / or software modules.

[0073] The splitter circuit 12 is designed such that it additionally couples or connects the antenna input 10a and the antenna output 10b to transmit the antenna signal A. As in Fig. As shown in Figure 1, this connection is made via a series circuit consisting of a first decoupling unit 14a, an amplifier unit 16 and a second decoupling unit 14b.

[0074] The decoupling units 14a, 14b serve in particular for signal filtering, so that only the antenna signal A, i.e., the desired useful signal for use in the tachograph 10, is available. Preferably, the decoupling units 14a, 14b are designed as electronic filters configured to filter DC electrical signals. After filtering, only AC electrical signals, such as the antenna signal A, are available. For this purpose, the decoupling units 14a, 14b can, for example, comprise one or more capacitors or capacitor systems. In the exemplary embodiment in Fig. 1 is the respective decoupling unit 14a, 14b symbolized by an electrical capacitor.

[0075] The decoupling units 14a and 14b are connected to each other by means of an amplifier unit 16. The amplifier unit 16 can, for example, be an operational amplifier circuit that amplifies the antenna signal A, or the remaining portion of the antenna signal A, provided after filtering by the first decoupling unit 14a, to the desired extent. This allows the filtered antenna signal A to be amplified, for example, to the signal level of the antenna signal A originally provided at the antenna input 10a, in order to then provide it to the vehicle receiver unit 3 at the antenna output 10b. This ensures that the vehicle receiver unit 3 receives a sufficient signal level of the antenna signal A to be able to use the antenna signal A itself for processing in the desired manner.

[0076] The tachograph 10 also includes, by way of example, a diagnostic unit 13. In the embodiment according to Fig. The diagnostic unit 13 is connected between the antenna input 10a and the first decoupling unit 14a. The diagnostic unit 13 is used to diagnose or record the antenna status of the vehicle antenna 2. This involves checking whether the vehicle antenna 2 is connected to the antenna input 10a (availability) and / or whether the vehicle antenna 2 is functioning correctly (functionality). Functionality, in this context, refers, for example, to the signal quality with which the vehicle antenna 2 provides an antenna signal A. The signal quality can be determined, for example, by the level of the antenna signal A or another signal parameter of the antenna signal A. How the antenna diagnostics can be implemented in practice will be described in more detail later.

[0077] In the present embodiment, the splitter circuit 12 includes an optional antenna simulation unit 15. Fig. The antenna simulation unit 15 is connected between the antenna output 10b and the second decoupling unit 14b. The antenna simulation unit 15 allows the vehicle receiver 3 to simulate or predetermine the presence and / or functionality of the vehicle antenna 2. This is particularly advantageous if the vehicle receiver 3 also has a diagnostic unit analogous to the diagnostic unit 13 for checking the antenna status of the vehicle antenna 2. Since this diagnostic information cannot be transmitted to the vehicle antenna 2 via the splitter circuit 12, the antenna function of the vehicle antenna 2 can be replicated in the splitter circuit 12 using the simulation unit 15.

[0078] According to Fig. The tachograph 10 also includes an optional tachograph antenna 17, which is assigned to the tachograph 10. The tachograph antenna 17 is an internal antenna, i.e., located or attached within the housing 19. A switching unit 18 of the tachograph 10 allows switching between either the vehicle antenna 2 or the tachograph antenna 17 for operation of the tachograph 10. For this purpose, the switching unit 18 is designed, for example, as an electronic switch or semiconductor switch and can be switched between at least two different switching states. In the first switching state, the vehicle antenna 2 is coupled to the processing unit 11 via the antenna input 10a. In the second switching state, the tachograph antenna 17 is coupled to the processing unit 11. The switching between the switching states can be performed, for example, by means of the processing unit 11.

[0079] The following will now be based on the exemplary embodiment according to Fig. 1. The function or use of the tachograph 10 in vehicle 1 will be described by way of example. The function will also be described in relation to... Fig. 2 referred. Fig. Figure 2 shows a schematic process flow diagram for a procedure for operating the tachograph 10.

[0080] During operation, the vehicle antenna 2, for example, receives satellite signals from a desired GNSS system and converts them from an electromagnetic signal into an electrical signal in a known manner. The electrical signal is the antenna signal A, which is present as an alternating voltage. The antenna signal A is applied to the antenna input 10a. The tachograph 10 can then detect or receive the antenna signal. This corresponds to the process flow diagram according to... Fig. 2 the step S1.

[0081] To determine the antenna status of the vehicle antenna 2, the diagnostic unit 13 also applies an internal diagnostic signal D1 to the antenna input 10a. This internal diagnostic signal D1 is, for example, a DC voltage. The antenna signal A and the diagnostic signal D1 are superimposed at the antenna input 10a to form the input signal E. The diagnostic unit 13 can detect the input signal E and derive an antenna signal value W from it, which contains or indicates the antenna status of the vehicle antenna 2. For example, the diagnostic unit 13 measures the current of the input signal E. The antenna signal value W can therefore be a current value. The information about the antenna status encoded in the antenna signal value W can be transmitted by the diagnostic unit 13 to the processing unit 11 for further processing.

[0082] In addition to the diagnostic unit 13, the splitter circuit 12 can also retrieve or acquire the input signal E at the antenna input A. In the splitter circuit 12, the input signal E is transmitted to the first decoupling unit 14a. This unit filters the DC component from the input signal E. This removes the diagnostic signal D1 from the input signal E, so that after the first decoupling unit 14a only the antenna signal A is available as the usable signal. From there, the antenna signal A is transmitted via two different signal paths or lines, one to the processing unit 11 and the other to the amplifier unit 16. This splitting of the signal paths describes the splitter function of the splitter circuit 12.

[0083] In order for the processing unit 11 to receive the filtered antenna signal A, the switching unit 18 is in its first switching state. In this first switching state, the antenna input 10a is connected to the processing unit 11. The processing unit 11 receives the filtered antenna signal A and can process it further, for example, to validate the vehicle parameters. Receiving and evaluating the antenna signal A corresponds to step S2 in the process flow diagram according to Fig. 2.

[0084] The processing includes, for example, comparing activity parameters specified by the antenna signal A, such as the vehicle's current position and / or the time, with the driving parameters that the tachograph 10 has recorded for journey monitoring, for example, from the vehicle systems. The evaluation is carried out according to known evaluation principles and is therefore not described in detail here.

[0085] The second signal path of the antenna signal A after the first decoupling unit 14a runs as described above via the amplifier unit 16 and the second decoupling unit 14b. This allows the splitter circuit 12 to transmit the antenna signal A from input 10a to output 10b. This corresponds to step S3 in the process flow diagram according to... Fig. 2.

[0086] Since the signal path has split and the antenna signal A is thereby attenuated, the antenna signal A can be amplified again in the amplifier unit 16 to a higher level, for example, the original level or a similar level. The amplified antenna signal A is then provided at the antenna output 10b via the decoupling unit 14b. The second decoupling unit 14b can now filter or cut off an external diagnostic signal D2, which the vehicle receiver unit 3 provides to the tachograph 10 for diagnosing the antenna status. The purpose is therefore to filter the external diagnostic signal D2, which could, for example, be a DC voltage, within the splitter circuit 12. This prevents the vehicle receiver unit 3 from directly diagnosing the vehicle antenna 2 itself via the splitter circuit 12.

[0087] The diagnostic function, however, is performed by the splitter circuit 12 itself. For this purpose, the splitter circuit 12 includes the antenna simulation unit 15. When supplied with the external diagnostic signal D2, the antenna simulation unit 15 of the vehicle receiver unit 13 can simulate or specify the antenna status of the vehicle antenna 2. For this purpose, the simulation unit 15 includes, for example, one or more electrical resistors that can be connected to the antenna output 10b of the vehicle antenna 2. When supplied with the diagnostic signal D2, an electrical current flows through the resistor(s), the value of which depends on the resistance values. By varying the resistance values, the electrical resistance exhibited by the vehicle antenna 2 during normal, functional operation can thus be replicated.

[0088] Preferably, the simulation unit 15 is adjusted based on the determined antenna status of the vehicle antenna 2. To determine the antenna status, the processing unit 11 can acquire and evaluate the antenna signal value W. For example, the processing unit 11 can compare the antenna signal value W with a predefined target value range. The target value range is the range of values ​​within which the antenna signal value W should lie when the vehicle antenna 2 is functioning correctly. The target value range can, for example, be specified by the vehicle antenna manufacturer or determined through testing or simulations.

[0089] If the comparison shows that the antenna signal value W is within the target range, i.e., neither exceeding nor falling below it, the vehicle antenna 2 is in a functional state. The processing unit 11 can then output or transmit a status signal S to the simulation unit 15. The status signal S contains information about the antenna status and, for example, associated settings for the simulation unit 15 to simulate the corresponding antenna status. When the simulation unit 15 is supplied with the status signal S, it sets, for example, the desired resistance value to replicate the functionality of the vehicle antenna 2. The resistor(s) can be switched on or off, for example, using a suitable switching unit.

[0090] If the comparison reveals that the antenna signal value W exceeds or falls below the target value range, this indicates that the vehicle antenna 2 is not functioning as intended. The processing unit then classifies the vehicle antenna 2 as either inoperative or malfunctioning. Subsequently, the processing unit 11 can send a corresponding status signal S to the simulation unit 15, which then switches off the simulation unit 15. When the diagnostic signal D2 is applied, the simulation unit 15 thus acts as if in electrical neutral, and the vehicle receiver unit 3 can diagnose the vehicle antenna as defective.

[0091] The result of evaluating the antenna signal value W can also be used to switch between the vehicle antenna 2 and the tachograph antenna 17. For example, if the evaluation of the antenna signal value W reveals that the vehicle antenna 2 is malfunctioning, i.e., the signal quality does not meet the desired value, the processing unit 11 can control the switching unit 18 to switch to the second switching state. In this second switching state, the tachograph antenna 17, and no longer the vehicle antenna 2, is coupled or connected to the processing unit 11. The acquisition of satellite signals is thus performed internally by the tachograph antenna 17 of the tachograph 10.

[0092] In embodiments other than those shown, it is possible to omit the tachograph antenna 17 in the tachograph 10. The tachograph then uses exclusively the external antenna (vehicle antenna 2), which is used for the desired antenna function.

[0093] Overall, the exemplary embodiments demonstrate the use of a mini-GNSS splitter (splitter circuit 12) in the DTCO. ® (Tachographs 10). Reference symbol list 1 vehicle 2 vehicle antennas 3 Vehicle receiving unit 10 Tachograph 10a Antenna input 10b Antenna output 11 Calculation unit 12 splitter circuit 13 Diagnostic Unit 14a first decoupling unit 14b second decoupling unit 15 antenna simulation unit 16 amplifier unit 17 Tachograph antenna 18 switching unit 19" enclosure A antenna signal D1 internal diagnostic signal D2 external diagnostic signal E Input signal S status signal S1 first step S2 second step S3 third step W antenna signal value

Claims

[1] Tachograph (10) for processing recorded driving parameters of a vehicle (1), comprising - an antenna input (10a) for connecting an external vehicle antenna (2), which is configured to provide GNSS signals as the respective antenna signal (A) to the antenna input (10a) when connected, and - a computing unit (11) which is designed to receive the respective antenna signal (A) and to evaluate the driving parameters recorded by the tachograph (10), characterized by , that - the tachograph (10) includes at least one antenna output (10b) for connecting a respective external vehicle receiver unit (3), and - the tachograph (10) includes a splitter circuit (12) which couples the antenna input (10a) and the at least one antenna output (10b) for transmitting the respective provided antenna signal (A). [2] Tachograph (10) according to claim 1, wherein the splitter circuit (12) comprises a diagnostic unit (13) configured to provide an internal diagnostic signal (D1) to the antenna input (10a), and the diagnostic unit (13) configured to determine an antenna signal value (W) from a resulting input signal (E) at the antenna input (10a), which comprises the antenna signal (A) and the diagnostic signal (D1), indicating an antenna status of the vehicle antenna (2). [3] Tachograph (10) according to claim 2, wherein the computing unit (11) is configured to evaluate the antenna signal value (W) according to a predetermined evaluation criterion to determine the antenna status. [4] Tachograph (10) according to claim 3, wherein the evaluation comprises checking whether the antenna signal value (W) deviates from a target value range specified according to the evaluation criterion, which the antenna signal value (W) has when the vehicle antenna (2) has a properly functioning antenna status. [5] Tachograph (10) according to any one of the preceding claims 2 to 4, wherein the splitter circuit (12) comprises a first decoupling unit (14a) configured to filter the internal diagnostic signal (D1) from the input signal (E) for processing the vehicle parameters by means of the computing unit (11). [6] Tachograph (10) according to claim 5, wherein the splitter circuit (12) has a second decoupling unit (14b) configured to filter an external diagnostic signal (D2) which the vehicle receiving unit (3) provides to the at least one antenna output (10b) in the connected state for determining an antenna status of the vehicle antenna (2). [7] Tachograph (10) according to one of the preceding claims, wherein the splitter circuit (12) comprises an antenna simulation unit (15) which, when supplied with an external diagnostic signal (D2) which the vehicle receiver unit (3) in the connected state provides to the at least one antenna output (10b) for determining an antenna status of the vehicle antenna (2), is configured to specify an antenna status of the vehicle antenna (2) to the vehicle receiver unit (3). [8] Tachograph (10) according to any one of the preceding claims 3 to 6 and according to claim 7, wherein the computing unit (11) is configured to couple the antenna simulation unit (15) with the at least one antenna output (10b) depending on the result of the evaluation to specify the antenna status of the vehicle antenna (2). [9] Tachograph (10) according to any one of the preceding claims 2 to 6 and claim 7, wherein the diagnostic unit (13) is configured to provide the antenna signal value (W) to the antenna simulation unit (15), and the antenna simulation unit (15) is configured to provide the vehicle receiving unit (3) with the antenna signal value (W) to specify the antenna status of the vehicle antenna (2). [10] Tachograph (10) according to any one of the preceding claims 7 to 9, wherein the antenna simulation unit (15) provides an electrical resistance. [11] Tachograph (10) according to one of the preceding claims, wherein the splitter circuit (12) comprises an amplifier unit (16) configured to amplify the antenna signal (A) provided via the antenna input (10a) for provision to the at least one antenna output (10b). [12] Tachograph (10) according to one of the preceding claims, wherein the tachograph (10) comprises an internal tachograph antenna (17) configured to provide GNSS signals as a further antenna signal to the computing unit (11) for processing the driving parameters recorded by the tachograph (10), and the tachograph (10) comprises a switching unit (18) which in a first switching state couples the vehicle antenna (2) to the computing unit (11) via the antenna input (10a) and in a second switching state couples the tachograph antenna (17) to the computing unit (11), and the computing unit (11) is configured to switch the switching unit (18) to the first or second switching state depending on the respective antenna status of the antenna signal (A) and the further antenna signal. [13] Vehicle (1) with a tachograph (10) according to one of the preceding claims and with an external vehicle antenna (2) and an external vehicle receiving unit (3) connected to the tachograph (10). [14] Method for processing driving parameters of a vehicle (1) recorded by a tachograph (10), wherein GNSS signals are recorded at an antenna input (10a) of the tachograph (10) as the respective antenna signal (A) of a connected external vehicle antenna (2), and the respective antenna signal (A) is received by means of a computing unit (11) of the tachograph (10) and evaluated for processing the driving parameters recorded by the tachograph (10), characterized by, that by means of a splitter circuit (12) of the tachograph (10) the antenna input (10a) is coupled with at least one antenna output (10b) of the tachograph (10) for connecting an external vehicle receiver unit (3), and by means of the splitter circuit (12) the respective provided antenna signal (A) is transmitted from the antenna input (10a) to the at least one antenna output (10b).

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