METHOD FOR RECORDING DRIVER ACTIVITY DATA OF A HAZARDOUS GOODS VEHICLE AS WELL AS FLEET MANAGEMENT SYSTEM AND DRIVER ACTIVITY DATA RECORDING UNIT FOR THE FLEET MANAGEMENT SYSTEM AND MOTOR VEHICLE

Description

[0001] The invention relates to a method for acquiring driver activity data from a vehicle transporting dangerous goods using a data service system, in particular a fleet management system. The vehicle transporting dangerous goods can provide an ADR mode for loading dangerous goods, which protects the vehicle against electrical sparking, but this deactivates the data acquisition unit, making continuous acquisition of driver activity data more difficult. The invention also relates to a fleet management system that can continuously acquire driver activity data despite the ADR mode, as well as a driver activity data acquisition unit for the fleet management system and a motor vehicle.

[0002] A fleet management system (FMS) can access driver activity data via a data acquisition unit for reliable recording of driver activity data, both when the ignition is switched on and off. However, a limitation arises with vehicles transporting dangerous goods according to the German Dangerous Goods Ordinance for Road, Rail and Inland Waterways (GGVSEB), internationally known as "ADR" vehicles (ADR = Accord relatif au transport international des merchandises Dangereuses par Route). These vehicles are equipped with a special shutdown device to de-energize areas or components of the vehicle during the loading and unloading of dangerous substances and goods. This operating state is referred to in this document as "ADR mode".

[0003] A data acquisition unit of a fleet management system is typically de-energized in ADR mode. In ADR mode, the fleet management system cannot actively access the vehicle interfaces to collect driver activity data. Therefore, no activity data or driver activity data, e.g., from the tachograph, can be read and processed in ADR mode. Consequently, a time gap arises in the fleet management system because information about activities and events in the hazardous materials vehicle is unavailable. In principle, past driver activity data could be retrieved remotely from a central server storage location, which stores the tachograph's driver activity data, e.g., for driver monitoring (compliance with driving times). However, this centrally stored driver activity data is usually only available with a time delay (e.g.,The data is retrieved weekly, making real-time tracking of a hazardous materials vehicle by a fleet management system impossible – especially since the remote download occurs via a protected data channel. Therefore, this data cannot be accessed directly.

[0004] Documents EP 2 272 052 B1 and EP 2 073 174 A2 describe a tachograph in which data transmission is independent of the power supply provided by the vehicle ignition.

[0005] US 2011 / 227970 A1 describes liquid crystal displays and a method to improve display quality and reduce streaky inequalities.

[0006] EP 3 521 844 A1 describes an antenna arrangement with a diagnostic unit, wherein the diagnostic unit outputs a signal when the voltage in the connecting line meets certain predefined criteria.

[0007] WO 2006 / 008527 A2 describes a tachograph which reads data from a digital card and writes it to that card, and subsequently enables communication with the driver of the vehicle containing the tachograph.

[0008] EP 2 626 251 B1 discloses a method for improving safety in a vehicle that includes at least one energy source.

[0009] The invention is based on the objective of enabling timely, in particular real-time and continuous recording of driver activity data in a motor vehicle despite ADR mode for a fleet management system or, more generally, a data service system.

[0010] The problem is solved by the subject matter of the independent patent claims. Advantageous embodiments of the invention are described by the dependent patent claims, the following description, and the figures.

[0011] As one solution, the invention comprises a method according to claim 1 for acquiring driver activity data from a vehicle carrying hazardous materials for a data service system, in particular a fleet management system. For the sake of clarity, reference is made below specifically to a fleet management system, but instead of a fleet management system, another data service system may also be provided, e.g., a data service system for vehicle maintenance (wear monitoring) or for driver monitoring (to ensure compliance with working time regulations). Another term for such a data service system is telematics system.

[0012] The method assumes that driver activity data in the dangerous goods vehicle is captured by a data acquisition unit of the fleet management system and transmitted to an external data collection unit of the fleet management system. The method according to the invention thus continues to allow the use of a data acquisition unit from a fleet management system, so that no complex modifications are necessary. The data acquisition unit may also be switched off in ADR mode. Such a data acquisition unit can, for example, be provided as a control unit or as an electronic circuit in the dangerous goods vehicle.

[0013] The procedure further assumes that the vehicle transporting dangerous goods is equipped with a tachograph and also has a shutdown device for an ADR mode in which at least the recording unit is switched off. Another term for such a tachograph is a digital tachograph, as legally required for vehicles transporting dangerous goods today. The "ADR mode" is the operating mode of the vehicle transporting dangerous goods described above, in which, for the taking on or dispensing of flammable or combustible hazardous materials, such as refueling or dispensing flammable gas and / or flammable liquid, electrical consumers in the vehicle are switched off or de-energized to prevent sparking.As is standard practice, the detection unit is also switched off because its function has not been required in ADR mode so far, and therefore in a dangerous goods vehicle the detection unit is coupled to the shutdown device in such a way that when the ADR mode is activated or switched on, the shutdown device also switches off or de-energizes the detection unit, thus making its operation impossible.

[0014] To ensure continuous recording of driver activity data, the tachograph is designed to continue operating, at least to the extent that it records and stores driver activity data generated during ADR mode, even when ADR mode is activated. After ADR mode is deactivated (i.e., when the recording unit restarts), the tachograph transmits the driver activity data stored during ADR mode to the recording unit via a communication link, triggered by an event. Alternatively, the tachograph may hold the driver activity data available for transmission or retrieval by the recording unit. The tachograph thus serves as a temporary storage location for the driver activity data. This data can then be retrieved from the tachograph by the recording unit or, for example,The data is automatically transmitted from the tachograph to the data acquisition unit at a predetermined transmission interval. The stored driver activity data is therefore either sent once or cyclically, or retrieved by the data acquisition unit.

[0015] This solution is based on the understanding that while a fleet management system's data acquisition unit is de-energized in ADR mode, the tachograph itself must still be operational. Although restrictions also apply to the tachograph—for example, potentially spark-generating devices such as lifting magnets or printers may not be operated in ADR mode—the recording of activities, driving and rest times, and thus the recording of driver activity data in general, must still be ensured by a separate power supply in the vehicle carrying dangerous goods.If, after reactivation of the data collection unit, the driver activity data recorded by the tachograph is transferred to the data collection unit, then information about activities and / or events that occurred during the activated ADR mode will also be available in the data collection unit. This can occur within less than ten minutes of the ADR mode being deactivated or the data collection unit being switched on, so that the driver activity data is available in the data collection unit and thus in the fleet management system from that point onward.

[0016] The invention offers the advantage that the data acquisition unit also makes available driver activity data from the hazardous materials vehicle that was generated or recorded during the activated ADR mode, i.e., when the data acquisition unit was switched off. This data is then made available in real time or very soon after the ADR mode is deactivated, by transferring this driver activity data from the tachograph to the data acquisition unit in the hazardous materials vehicle (i.e., onboard) after the ADR mode is deactivated. The data acquisition unit receives the stored driver activity data within ten minutes of the ADR mode being deactivated and transmits it to the fleet management system's data collection unit. This is still sufficient to implement "real-time" fleet management.

[0017] A collection unit can be implemented, for example, by an internet server, i.e., a computer or computer network. The acquisition unit and the collection unit can be coupled in a known manner, for example, via an internet connection and / or a wireless connection, such as a mobile network connection and / or a WLAN connection (wireless local area network).

[0018] The invention also includes further developments or enhancements that result in additional advantages.

[0019] A further development provides that at least one of the following is detected in the tachograph as a trigger event: exiting ADR mode; reaching a transmission time for a message to be sent once or cyclically via the communication link, in which the stored driver activity data is to be transmitted; receiving a diagnostic message by which the recording unit requests the transmission of the stored driver activity data. Exiting ADR mode can be detected by the transition from activated to deactivated ADR mode, i.e., by the switch to normal operating mode when the shutdown device reactivates the recording unit. This can be detected, for example, by the switching state of the shutdown device itself. The shutdown device can be designed in a manner known per se, as is also used in the prior art in connection with ADR mode.It can be extended to provide its current switching state (ADR mode on or off) as a control signal. Additionally or alternatively, the data set of stored driver activity data can also be transmitted cyclically or on a time-controlled basis via a corresponding message. For this purpose, the transmission of at least one message can occur at a predetermined time or at several predetermined transmission times via the communication link. For example, the respective message could be a CAN message that is provided on a CAN bus (CAN - controller area network) according to a transmission schedule.Additionally or alternatively, driver activity data can be actively retrieved. For this purpose, a predefined diagnostic message can be defined, for example, in a communication protocol. This message prompts or controls the tachograph to transmit or output the stored driver activity data so that it is transferred to the data acquisition unit. Transmitting a diagnostic message has the advantage that the stored driver activity data is only made available when the data acquisition unit is ready, which it can signal by generating or transmitting the diagnostic message.Cyclical transmission at predetermined transmission times or at a single, predetermined transmission time offers the advantage that the stored driver activity data can be provided regardless of whether it originates from ADR mode or other driver activity data (ADR mode deactivated). This allows the same logic for sending messages with stored driver activity data to be used regardless of the ADR mode. Using exiting ADR mode as a trigger to transmit the stored driver activity data has the advantage of minimizing the time delay between deactivating ADR mode and sending the stored driver activity data. A diagnostic message can, for example, be defined based on the ISO 14229 standard.

[0020] A further development proposes that, in response to a trigger event, the tachograph transmits a predetermined number N of the most recently stored driver activity data (i.e., regardless of the ADR mode activation status). In other words, regardless of whether the ADR mode is activated, the last N (predetermined number) of events and / or activities are always output or transmitted as stored driver activity data. This means that in response to the trigger event, the tachograph always outputs the predetermined amount of the most recently stored driver activity data. This data may have been generated wholly or partially during the activated ADR mode, but also during the deactivated ADR mode.Therefore, no active detection or assignment is necessary to determine whether driver activity data was recorded with ADR mode activated or deactivated. This makes implementation particularly simple. The predetermined number N can, for example, specify that the last five to fifteen events and / or activities are transmitted in total.

[0021] A further development involves the tachograph temporarily storing the most recently recorded driver activity data in a ring buffer. The contents of this ring buffer are then transferred upon detection of a trigger event. Using a ring buffer allows for particularly efficient management of driver activity data, ensuring that the current, predetermined number of events and / or activities are always available. Compiling or generating a message containing the stored driver activity data is also implemented with exceptional efficiency. This system approach can function even without a driver card inserted, meaning the tachograph is not explicitly activated by a specific driver. Furthermore, it is not dependent on the storage capacity of a driver's card.

[0022] A further development proposes that the data acquisition unit or the data collection unit compare the already recorded driver activity data with the most recently transmitted driver activity data and discard any duplicate data. This implementation requires no management or adjustments within the tachograph itself to ensure that it only transmits driver activity data once in response to a transmission command or trigger event. It can always react to a trigger event in the same way, for example, by transmitting the predetermined number N of stored driver activity data, even if this results in certain driver activity data being transmitted two or more times. This can then be compensated for or balanced out in the data acquisition unit or the data collection unit, where more processing power is available for this task.

[0023] A further development envisions that the data acquisition unit will always indirectly determine the driver activity data generated, even when ADR mode is deactivated, by reading and / or receiving the driver activity data recorded by the tachograph. In other words, the tachograph can always be used by the data acquisition unit to record driver activity data, so that no additional hardware or circuitry is required in the data acquisition unit for this purpose, because the hardware or circuitry of the tachograph is used to record driver activity data – data that is recorded, or is intended to be recorded, both during activated ADR mode (EE switched off) and when ADR mode is deactivated (i.e., when the data acquisition unit is switched on).

[0024] A fleet management system can thus access the driver activity data from the tachograph / digital tachograph via its data acquisition unit, regardless of whether the ignition is switched on or off. The tachograph can offer an interface for this purpose, such as the CAN interface, the front interface (connection on the front of the device), or the familiar D8 Info interface (D8 = pin 8 on connector "D" according to ISO 16844-1). Messages on the CAN interface are provided either cyclically or via a diagnostic protocol according to ISO 14229. Furthermore, the tachograph also offers driver-related data via a "remote download" interface. This driver data is transmitted securely between the tachograph and the reader at the company. A fleet management system cannot directly access this data in plain text. The driver data can also be provided as part of the driver activity data.

[0025] A further development proposes recording at least some of the journey data from the hazardous materials vehicle, including signaled activities such as driving, rest periods, and other working hours. This data could then be used to calculate, for example, a driver's compensation more accurately.

[0026] A further development envisions recording at least some of the trip data from the vehicle carrying dangerous goods, including events such as tampering with the tachograph, error messages, and safety messages. This allows the fleet management system to promptly detect and identify driver errors and / or operational problems with the vehicle. In ADR mode, the ignition is off, meaning the "driving" activity is not possible unless the vehicle has been tampered with. However, an error message, such as a "sensor malfunction" (if the speed sensor is defective), can be signaled or occur. A safety violation can occur, for example, if someone attempts to manually remove the driver's card from the tachograph slot while in ADR mode (which is prohibited).

[0027] Furthermore, a tachograph for a vehicle carrying dangerous goods is disclosed. A processor circuit of the tachograph is configured or adapted to record and store driver activity data generated during an activated ADR mode of the vehicle carrying dangerous goods. Subsequently, depending on a trigger event, the driver activity data stored during the activated ADR mode is transmitted via a communication link to a data acquisition unit of a fleet management system or made available for retrieval. Retrieval can be initiated by a predefined diagnostic message, as already described. The driver activity data describes, in particular, activities of the driver other than driving, since the vehicle carrying dangerous goods cannot, for example, drive in ADR mode.The tachograph or data recorder can, for example, comprise at least one microcontroller and / or at least one microprocessor and / or at least one FPGA and / or at least one ASIC (application-specific integrated circuit) as a processor circuit. The processor circuit can include a data memory that can store program code or software which, when executed by the processor circuit, causes it to execute an embodiment of the method according to the invention. For this purpose, the data memory can be coupled to the at least one microprocessor and / or at least one microcontroller / FPGA / ASIC. The communication link can be configured, for example, as a CAN bus and / or as a cable connection via the described front interface and / or the described D8 interface. The communication link can be wireless, for example, based on Bluetooth and / or WLAN.

[0028] As a further solution, the invention comprises a motor vehicle according to claim 1. An embodiment of the aforementioned tachograph is also provided in the motor vehicle. Thus, the motor vehicle enables continuous recording of driver activity data for a fleet management system unit, both with the ADR mode deactivated and activated. The motor vehicle can, in particular, be configured as a hazardous materials vehicle, whereby the recording unit is deactivated in ADR mode when loading hazardous materials. However, it may happen that the driver does not work continuously during the aforementioned activation of the ADR mode.

[0029] As a further solution, the invention comprises a data acquisition unit according to claim 9 for a fleet management system. The data acquisition unit is configured to receive the driver activity data stored in a tachograph during the activated ADR mode of a vehicle carrying dangerous goods after it has been reactivated by exiting that mode and to transmit this data to an external data collection unit of the fleet management system. The data acquisition unit can be implemented as described on the basis of a processor circuit that may include at least one microcontroller and / or at least one microprocessor. The data acquisition unit can be configured to send a diagnostic message to a tachograph via a communication link, thereby causing the tachograph to transmit stored driver activity data to the data acquisition unit.The transmission of the diagnostic message can be triggered, in particular, after the recording unit is switched on or activated. This may require the detection of a start-up or boot process of the recording unit, as occurs when the ADR mode is deactivated and the recording unit is thereby supplied with electrical power again. By reading the driver activity data from the tachograph's own memory, the system remains independent, as previously mentioned, of whether the driver activity data is already stored on the driver's card or subsequently stored there as well.

[0030] As a further solution, the invention includes a fleet management system according to claim 11.

[0031] Such a fleet management system or data service system is able, thanks to the continuous recording of driver activity data, to determine, record, or evaluate the condition and / or the course of the condition relevant for fleet management, even during an activated ADR mode in a motor vehicle, in particular a dangerous goods vehicle.

[0032] The invention also includes further developments or refinements of the detection unit, which exhibit features already described in connection with the further developments of the method according to the invention. For this reason, the corresponding further developments of the detection unit according to the invention are not described again here.

[0033] An embodiment of the invention is described below. The following is shown: Fig. 1 is a schematic representation of an embodiment of the fleet management system according to the invention with an embodiment of the motor vehicle according to the invention, in which an embodiment of the recording unit and the tachograph according to the invention can perform an embodiment of the method according to the invention; and Fig. 2 is a diagram illustrating an embodiment of the method according to the invention, as it is implemented in the fleet management system of Fig. 1 can be carried out.

[0034] The embodiment described below is a preferred embodiment of the invention.

[0035] In the figures, functionally identical elements are each provided with the same reference symbols.

[0036] Fig. 1 Figure 1 shows a data service system, which is implemented here as an example of a fleet management system 10 and comprises motor vehicles 11 and an external data collection unit 12. Further elements of the fleet management system 10, as known from the prior art, are not shown or explained here. Furthermore, only one of the motor vehicles 11 is described representatively below; the other motor vehicles 11 can be configured in the same way.

[0037] The respective motor vehicle 11 can, for example, be designed as a hazardous materials vehicle, such as a tanker for gasoline or diesel or a transport vehicle for natural gas, to name just a few examples. Generally, it can be a hazardous materials vehicle transporting a flammable substance, i.e., a substance that can be ignited, for example, by an electric spark. The collection unit 12 can, for example, be provided on the internet 13 as a computer or computer network.

[0038] The vehicle 11 may be equipped with a communication unit 14, by means of which a data connection 15 can be established or operated between a data acquisition unit 16 of the fleet management system 10 in the vehicle 11 and the data collection unit 12. The data connection 15 may, for example, be based on an internet connection. Furthermore, the data connection 15 may include a radio connection 17, which can be operated between the communication unit 14 and, for example, a mobile network 18 and / or a WLAN 19. The communication unit 14 of the vehicle 11 may, for example, include a mobile communication module and / or a WLAN radio module.

[0039] The data acquisition unit 16 can record driver activity data 20 of the vehicle 11, which can then be transmitted to the data collection unit 12 via the data connection 15. The data collection unit 12 thus makes driver activity data 20 of the vehicle 11 available in the fleet management system 10 on the internet 13, which can be used in a known manner to generate fleet information 21 and / or transport orders 22.

[0040] In the motor vehicle 11, a shut-off device 23 can be provided for loading and / or unloading the hazardous material, in particular the flammable hazardous material. This device can implement an ADR mode for the motor vehicle 11, in which electrical consumers that are not necessary during the loading of the hazardous material are electrically disconnected from an electrical power source 24, for example, an electrical power grid or the vehicle's electrical system. This can be achieved, for example, by opening a relay or switch 25. The figure shows how, in a circuit with a positive line 26 and a ground potential 27 of the power source 24, the power supply to the detection unit 16 can be interrupted by activating the ADR mode (opening the switch 25) using the switch 25. The switch 25 is shown here only symbolically. It is known how an ADR mode can be implemented in a motor vehicle 11.Such a known implementation can also be used here.

[0041] Even when ADR mode is activated and the recording unit 16 is switched off, the resulting driver activity data 20 in the motor vehicle 11 are available in the fleet management system with a slight time delay (in particular, a maximum delay of 10 minutes), namely after deactivating ADR mode and once the recording unit 16 is supplied with electrical power or voltage again. Specifically, they are then transferred to the collection unit 12.

[0042] To achieve this, the recording unit 16 can be provided for to receive or read the driver activity data 20 from a tachograph or data recorder 28, which continuously records the driver activity data in both deactivated and activated ADR mode. Such driver activity data 20 can, for example, be activities 29 and / or events 30, such as can be recorded by the data recorder 28 in a known manner according to the prior art. If the ADR mode is activated and then exited or deactivated, a trigger event 31 can cause the driver activity data 20 stored during the activated ADR mode to be transmitted from the data recorder 28 to the recording unit 16 via a communication link 32, for example, a CAN bus and / or a cable connection.

[0043] Fig. 2This describes an exemplary loading or unloading process in which the ADR mode is activated by actuating the shut-off device 23 in a motor vehicle 11. Actuating the shut-off device 23 can be done, for example, by a driver 40 in a manner known per se. The processes are shown over time T. The motor vehicle can be a tanker truck for gasoline.

[0044] The tanker truck driver, or driver 40, can drive to a filling station to refuel the tanker truck with gasoline. Driver 40 parks the vehicle 11 and activates the ADR mode. Driver 40 refuels the vehicle 11 for a period of, for example, 20 minutes. Their activity 29 is "work" in this case. Afterwards, driver 40 takes a break of, for example, 15 minutes, meaning activity 29 is recognized as "break / rest time" because driver 40 logs off the tachograph 28. After the break, driver 40 performs a pre-departure check, which again corresponds to activity 29 as "work" and takes, for example, 5 minutes. Only then does driver 40 deactivate the ADR mode, start the vehicle 11, and drive off: The total duration of this process can be 1 minute. All activities (work / rest) are precisely recorded on the driver card or the journey log.However, the FMS 10 can initially only detect the activity that is communicated via an interface of the tachograph 28 after leaving ADR mode.

[0045] Thus, without the additional transmission of the stored driver activity data 20 (concerning the activities 29 during the activated ADR mode), it would be unclear what happened during the example 40 minutes. With the new approach, the tachograph / drive recorder 28 can provide the driver activity data 20 without gaps, so that the activities 29 during the ADR mode can be processed subsequently without gaps.

[0046] This results in the following steps in particular: S10: Driver activates ADR mode. S11: Vehicle electronics (also recording unit) are disconnected from the power supply. S12: The shutdown device 23 signals to the tachograph 28 that ADR mode is activated. S13: Vehicle can be refueled. S14: Activities 29 are detected (e.g., activity change: "Break", "Working time"). S15: Driver activity is recorded as driver activity data. S16: Driver deactivates ADR mode. S17: Vehicle electronics are connected to the power supply. S18: Data query. S19: Transmission of the stored driver activity data (activity report). S20: Processing of the driver activity data inside and outside the vehicle 11 is possible.

[0047] The tachograph records and stores all legally required activities and events, regardless of ignition status and ADR mode. Provided the driver has consented to the distribution of their personal data, the tachograph can make the data generated in ADR mode available after exiting ADR mode via at least one additional CAN message or diagnostic data. This allows the FMS to access this data after exiting ADR mode and seamlessly reconstruct the activities and events. Unlike current technology, this allows for the immediate output of these activities occurring in the interim after exiting ADR mode, enabling the FMS system to resume real-time tracking of activities immediately.

[0048] Further advantages include seamless recording and processing of activities and events recorded in ADR mode. This new functionality ensures fair payment for drivers, who can now be paid down to the minute for their activities, even in ADR mode. This will be even more important in the future in conjunction with the regulations of the Mobility Package. Drivers will be paid the minimum wage of the respective EU member state when posted to work. Therefore, every minute that can be billed counts. Dispatchers, who monitor the driving, working, and rest times of deployed drivers, can also use the available data to deploy their drivers more effectively. It will also eliminate the need for external electronic systems that must comply with ADR regulations to record these activities, thereby improving the efficiency of the vehicle system.Immediate resumption of real-time tracking of driver activities after exiting ADR mode, thus enabling real-time planning of drivers with regard to working time and driving time.

[0049] Overall, this example shows how a mechanism or logic for activity tracking in ADR mode can be provided for telematics systems in conjunction with the tachograph. Reference symbol list

[0050] 10 Fleet management system 11 Motor vehicle 12 Collection unit 13 Internet 14 Communication unit 15 Data connection 16 Recording unit 17 Radio connection 18 Mobile network 19 WLAN 20 Trip data 21 Fleet information 22 Transport orders 23 Shutdown device 24 Power source 25 Switch 26 Positive line 27 Ground potential 28 Tachograph 29 Activity 30 Events 31 Trigger event 32 Communication connection 40 Driver

Claims

1. A method for detecting driver activity data (20) of a hazardous goods vehicle for a data service system, in particular a fleet management system (10), wherein the driver activity data (20) are recorded in the hazardous goods vehicle by a detection unit (16) of the data service system and transmitted to an off-board collection unit (12) of the data service system, and wherein a tachograph (28) is operated in the hazardous goods vehicle and a defeat device (23) for a ADR mode, in which at least the detection unit (16) is switched off, wherein, with the ADR mode activated, the tachograph (28), which must continue to be operated, continues to be operated at least to the effect that the tachograph (28) detects and stores driver activity data (20) arising during the ADR mode, and, after deactivation of the ADR mode, when the detection unit (16) is restarted, the driver activity data (20) stored during the activated ADR mode are either retrieved from the tachograph (28) by the recording unit (16) via a communication link (32) and / or are transmitted from the tachograph (28) to the recording unit (16) on the basis of a triggering event (31), wherein the recording unit (16) implements a data service system (10) which is characterised in that the recording unit (16) receives within ten minutes of deactivating the ADR mode the driver activity data (20) and transfers them to the collection unit (12) of the data service system (10).

2. The method according to claim 1, wherein, as the triggering event (31), at least one of the following is detected in the tachograph (28): - exiting the ADR mode, - reaching a transmission time of a message to be sent once or cyclically via the communication link (32) in which the stored driver activity data (20) are to be transmitted, - receiving a diagnostic message by means of which the detection unit (16) requests the storage of the stored driver activity data (20) to be sent.

3. The method according to any one of the preceding claims, wherein a predetermined number of driver activity data (20) most recently stored in total is transmitted from the tachograph (28) by the tachograph (28) in response to the triggering event (31).

4. The method according to any one of the preceding claims, wherein the tachograph (28) buffer-stores the most recently recorded driver activity data (20) in a ring memory and the content of the ring memory is transmitted on the basis of detection of the triggering event (31).

5. The method according to any one of the preceding claims, wherein in the detection unit (16) or in the collection unit (12), the driver activity data (20) that have already been detected are compared with the most recently transmitted driver activity data (20) and driver activity data (20) detected as occurring twice are rejected.

6. The method according to any one of the preceding claims, wherein, even when the ADR mode is deactivated, the detection unit (16) ascertains the driver activity data (20) then arising indirectly by means of the tachograph (28) by reading and / or receiving the driver activity data (20) recorded by the tachograph (28).

7. The method according to any one of the preceding claims, wherein activities (29), in particular driving, rest periods, other working hours, signalled in the hazardous goods vehicle are recorded as at least a part of the driver activity data (20).

8. The method according to any one of the preceding claims, wherein events (30), in particular a manipulation of the tachograph (28), an error message, a security breach which are signalled in the hazardous goods vehicle are recorded as at least a portion of the driver activity data (20).

9. A detection unit (16) for a fleet management system (10), wherein the detection unit (16) is configured, after being switched on again by exiting an ADR mode of a hazardous goods vehicle, to retrieve driver activity data (20) stored in a tachograph (28) while the ADR mode is activated from the tachograph (28) and to send them out to an off-board collection unit (12) of the fleet management system (10), wherein the detection unit (16) has a fleet management system (10), which is characterized in that the detection unit (16) is configured to receive the stored driver activity data (20) and to transfer them to the collection unit (12) of the fleet management system (10) within ten minutes of deactivation of the ADR mode.

10. A motor vehicle (11) having a detection unit (16) of a fleet management system (10) and having a defeat device (23) for an ADR mode in which at least the detection unit (16) is switched off, wherein a tachograph (28) for a hazardous goods vehicle is provided in the motor vehicle (11), wherein a processor circuit of the tachograph (28) is adapted for the tachograph (28) to detect and store driver activity data (20) generated while the hazardous goods vehicle is in activated ADR mode and, depending on a triggering event (31), to send the driver activity data (20) stored during the activated ADR mode to the detection unit (16) via a communication link (32) or to make them available for retrieval, wherein the detection unit (16) is designed according to claim 9.

11. A fleet management system (10) having multiple motor vehicles (11) according to claim 10 and a collecting unit (12) for receiving driver activity data (20) from the motor vehicles (11), wherein the collecting unit (12) is configured to provide a fleet management functionality for the motor vehicles (11) by means of the received driver activity data (20).