DATA COLLECTION DEVICE FOR MOBILE DEVICES, METHOD FOR PERFORMING A PRELIMINARY ANALYSIS IN A DATA COLLECTION DEVICE, VEHICLE AND CORRESPONDINGLY DESIGNED COMPUTER PROGRAM

Description

[0001] The invention relates to the technical field of systems for data acquisition during the testing and / or operation of mobile devices, particularly in vehicles. This involves, for example, testing a specific behavior of a control system of the mobile device and / or observing the ongoing operation of the system for optimization purposes. In order to capture the control behavior, data series are established and general rules are established for how an evaluation value can be generated from a data series. Classic functions include, for example, average value, minimum / maximum, number of elements, or sum of the elements. Statistical evaluation methods can also be used to obtain evaluation values. Examples of such evaluation values include: mode, median, arithmetic mean, standard deviation, upper and lower quantile, etc.The usual approach to data collection involves capturing as much data as possible, storing it, and transferring it to a backend server where it is then analyzed.

[0002] From DE 10 2017 201 804 A1 a method for recording data from a vehicle is known, with which sensor data is recorded on an event-based basis and stored in a memory.

[0003] US 2012 053 778 A1 discloses a method and device for remote vehicle diagnostics. Abnormal events are recorded, and pre- and post-event data is stored in a data set that is transmitted to an external location. The data is analyzed there. Workshop visits can then be scheduled.

[0004] From DE 10 2008 047 727 A1 a data recorder for recording critical driving situations is known, which records the measurement data of a sensor system when a critical driving situation has been detected.

[0005] From DE 10 2008 015 352 A1, a computer program is known that causes the bus traffic exchanged via the vehicle's data bus to be recorded and, when a trigger event occurs, the overwriting of the ring buffer is stopped in order to transfer the contents to a non-volatile memory.

[0006] DE 10 2017 206 073 A1 discloses a data collection method in which the amount of data to be transmitted is small. For this purpose, the data type to be sent is requested from a central location.

[0007] The known solutions suffer from various disadvantages. This was recognized within the scope of the invention. The problem with currently known data acquisition systems for testing various systems of mobile devices, especially vehicles, is that they record and store all data traffic on an internal communications bus, and if necessary, transmit it to an external processing unit, where the data is then analyzed. This results in significant costs for data storage, data transmission, and data analysis.

[0008] There is therefore a need for further improvements in data collection systems.

[0009] The invention aims to find such an approach. This object is achieved by a data acquisition device according to claim 1, a method for performing a preliminary analysis in a data acquisition device according to claim 11, a vehicle according to claim 12, and a computer program according to claim 13.

[0010] The dependent claims contain advantageous developments and improvements of the invention according to the following description of these measures.

[0011] In one embodiment, the invention consists in a data acquisition device for mobile devices. This data acquisition device is equipped with a computing unit and a memory unit. It further comprises a communications module configured to transmit acquired data to a backend server. Additionally, a bus interface is provided for receiving messages transmitted via an internal communications bus of the mobile device. The computing unit is configured to form a data series with the data received in the messages and store it in the memory unit.A special feature is that the computing unit is designed to perform a preliminary analysis of the stored data series in order to extract at least one region of interest from the data series and forward it to the communication module, which is configured to transmit the at least one extracted region of the data series to the backend server. This procedure corresponds to data aggregation. If several regions of interest are combined, they are combined and transmitted. Regions of no interest are not transmitted. This form of improved data acquisition device offers the advantage that significantly less data needs to be transmitted to the backend server via the wireless interface. At the same time, the storage requirements on the backend server are considerably reduced, and the effort required for data analysis on the backend server is likewise reduced.This advantage becomes particularly clear when testing a braking system. The braking process is short compared to the entire test drive. If only the relevant data is selected and transmitted through pre-analysis, data transfer overhead can be reduced by more than 90%. The storage and analysis overhead on the backend server are correspondingly reduced.

[0012] It is advantageous to store the acquired data series in time series format. If the measurement times are not transmitted via the internal communication bus, it is advantageous if the computing device is designed to record the times of receipt of the received messages in the data series along with the data of the respective received message. By recording the times, the chronological order of the data is documented, and the reference to the various test phases can always be established.

[0013] In an expanded embodiment of the invention, it is advantageous if the communication module is configured to receive at least one configuration message, wherein the at least one configuration message contains a specification for how the data of a message transmitted via the internal communication bus should be evaluated. This is important if the data acquisition device does not store the formatting of all messages to be received. Integer numbers, floating-point numbers, etc., can be contained in the messages, and the configuration message can enable the data acquisition device to convert the data into the format required for data analysis.

[0014] In this regard, it is advantageous if the computing device is designed to compile the data series with the data of the received messages according to the specification in the at least one configuration message. For example, by applying the specification of multiplying the received integer number by a scaling factor and adding an offset, the actual measured value can be recovered in a measurement unit as a floating-point number.

[0015] A typical application where the data acquisition device can be used advantageously is where the acquired data corresponds to measured data from sensors or data calculated by computing units. The calculated data can be derived from measured data.

[0016] Such data acquisition devices can be used very advantageously for testing vehicle systems. In this case, the mobile device corresponds to a vehicle, and the internal communication bus can, for example, correspond to the vehicle's CAN bus, corresponding to a Controller Area Network. However, various other bus systems are also in use today, to which data acquisition devices can also be connected. Other examples that can be used instead of the vehicle's CAN bus or CAN bus line include the Flexray bus, the LIN bus (Local Interconnect Network), the Ethernet bus, the Automotive Ethernet, and the MOST bus (Media Oriented System Transport).

[0017] In one example, the vehicle may be a towing vehicle or a trailer vehicle, and the trailer vehicle may be equipped with a compressed air-operated braking system. The braking system of the trailer vehicle or the towing vehicle is then tested using the data acquisition device according to the invention.

[0018] To test the trailer's braking system, it is advantageous to connect the data acquisition device to the trailer's internal CAN bus, to which a brake control unit is connected. The brake control unit transmits data from a number of brake pressure sensors and / or wheel speed sensors connected to the brake control unit via the CAN bus or CAN bus line. The data acquisition device then records the data from the brake pressure sensors and / or wheel speed sensors.

[0019] For testing and / or assessing the condition of the braking system, it is advantageous if the at least one configuration message sent to the data acquisition device contains at least the message identifier of the CAN message used to transmit the measured brake pressure of a brake pressure sensor, as well as an indication of the minimum relative brake pressure change that is still tolerable compared to the immediately preceding measured value of the brake pressure, in order to be able to assign the measured value to a range of relatively constant brake pressure. The braking system test involves the question of what the deceleration is at a constant brake pressure. For this purpose, the configuration message is designed to select the ranges of interest for this question.

[0020] In this regard, it is also advantageous if the specification in the at least one configuration message includes at least the message identifier of the CAN message used to transmit the measured wheel speed of a wheel speed sensor. This allows for the exclusion of areas where the brake is applied while the vehicle is stationary.

[0021] In another embodiment, the invention relates to a method for performing a preliminary analysis in a data acquisition device according to the invention. In this regard, it is advantageous that the preliminary analysis includes a data aggregation step. This allows the entire data set to be restricted to specific areas of interest.

[0022] The data aggregation step includes a step of calculating the relative change of the data in the data series.

[0023] In addition, data aggregation involves a step of assigning a marker to a date in the data series. This step assigns the marker to the respective date if the relative change of the date compared to the previous value is smaller than a minimum allowable reference value. This allows a region of interest to be found more quickly in the large data set.

[0024] The pre-analysis includes a step of counting the consecutive marked data in the data series during which the mobile device is still moving. In one example, this can be used to determine the longest duration range in which a system under test is actuated with a relatively constant setpoint.

[0025] The region of interest is determined by a step of determining the region in the data series that contains the maximum number of immediately consecutive marked data.

[0026] The section of the data series with the maximum number of consecutive marked data points is sent to a backend server. There, the data can be archived and subsequently analyzed.

[0027] In a further embodiment, the invention relates to a vehicle equipped with a data acquisition device according to the invention. Such data acquisition devices can thus also be used as standard equipment to monitor the operation of the vehicle.

[0028] The invention further relates to a computer program which is designed to carry out the steps of the method according to the invention when executed in a computing device.

[0029] Embodiments of the invention are illustrated in the drawings and are explained in more detail below with reference to the figures.

[0030] They show: Fig. 1 shows the principle of radio communication between a vehicle and a backend server via a publicly accessible mobile radio system; Fig. 2 shows a circuit diagram for the electronic and pneumatic equipment of a trailer vehicle equipped with a compressed air braking system; Fig. 3 shows the rough format of a CAN bus message with CAN bus identifier and payload field; Fig. 4 shows an example of a data series for recording the braking behavior of the trailer vehicle; Fig. 5 shows a flow chart for a computer program with which an inventive pre-processing of the data series can be implemented; Fig. 6 shows an associated measured value diagram for the data series of Fig. 4 with representation of the interesting range of constant brake pressure during a braking operation; and Fig. 7 shows another measured value diagram for another series of measured values, with representation of the interesting range of constant brake pressure during a braking operation.

[0031] The present description illustrates the principles of the inventive disclosure. It is thus understood that those skilled in the art will be able to devise various arrangements that, although not explicitly described herein, embody the principles of the inventive disclosure and are also intended to be protected within their scope.

[0032] Fig. 1 shows a schematic diagram for the transmission of measured value series measured during test drives on a test track. It depicts a commercial vehicle. Reference number 10 denotes the towing vehicle of a truck. The towing vehicle 10 pulls a trailer 20. Both the towing vehicle 10 and the trailer 20 are equipped with a data acquisition unit 130a, 130b. This data acquisition unit 130a, 130b serves to store the measured values supplied by sensors in measured value series. General data series can also be stored in the same way, with the data being calculated from measured values by computing units if necessary. The data acquisition unit 130a, 130b can also be used to preprocess the data series.

[0033] It can also be equipped with a communication module 136 configured to conduct wireless communication. Communication can be conducted either via a public cellular mobile network such as LTE (Long Term Evolution) or 5G, or via an ad hoc wireless network designed for communication to and from the vehicle. An example is the WLAN p communication system specified in the IEEE 802.11 p standard. The (preprocessed) data can be transmitted via the communication module 136 to a backend server 320, where the analysis of the data series also takes place.

[0034] The following describes an approach for an advanced form of data aggregation. The goal is to identify and extract a region of interest from a series of measurements. The aggregation rule on the in-vehicle unit, along with the definition of the messages and trigger conditions, can be dynamically configured via a cellular connection.

[0035] For a specific application, the longest constant pressure curve during a braking process needs to be determined in order to obtain precise information about the vehicle's deceleration in this range. Thus, there is a variable (pressure curve) that can move within a certain range to be considered constant, and this determines the time range for the extraction of a second variable (wheel speed). (As a variation, we could also focus on determining the longest linear range of a variable.)

[0036] Fig. 1 also shows the system architecture for vehicle communication using cellular mobile radio. Fig. 1 A commercial vehicle was presented as an example. However, any other vehicle could also be considered as a vehicle. Examples of other vehicles include: passenger cars, buses, agricultural machinery, construction machinery, camping vehicles, motorcycles, bicycles, scooters, wheelchairs, rail vehicles, etc. The use of the invention in vehicles would generally be applicable to land vehicles, rail vehicles, watercraft, and aircraft. Furthermore, the use of the invention is not limited to vehicles. The use of the invention is generally applicable to practically all areas of electrical engineering. Further examples include machinery and systems, small electrical appliances, consumer electronics devices, white goods devices, medical devices, etc. This list is not intended to be exhaustive. The connection of devices to the "cloud" is also penetrating ever more areas.A typical keyword for this is the term "Internet of Things" (IoT), which represents a technological trend whereby more and more devices in industry, commerce, and households are connected to the internet through the use of newer communication technologies such as 5G, LAN, or Wi-Fi. The recorded data series correspond to time series. This means that the respective measurement time is also noted when the respective measured value is recorded. In a measurement series in which only one measured variable is recorded, the measurement series consists of a number of consecutive measured values with the corresponding measurement times.

[0037] Vehicles 10 and 20 are each equipped with a data acquisition unit 130a, 130b. In one example, the braking system of trailer vehicle 20 is to be tested. The braking pressure is determined by the braking system in trailer vehicle 20 itself, but the desired deceleration of the vehicle is specified by the test driver, who presses the brake pedal during braking. The first data acquisition unit 130a can also record the braking command, since the braking command is transmitted from towing vehicle 10 to trailer vehicle 20 via a communications bus. If the braking system of towing vehicle 10 is to be tested, a second data acquisition unit 130b can be connected in towing vehicle 10, which can be constructed in the same way as the first data acquisition unit 130a.

[0038] Alternatively, only a second data acquisition unit 130b can be used in the towing vehicle 10, for example, if the trailer vehicle 20 does not have a data acquisition unit 130a or no trailer vehicle 20 is coupled to the towing vehicle 10. Accordingly, the description of the technical structure and functionality of the first data acquisition unit 130a selected here as an example is to be understood as a general description of a data acquisition unit according to the invention and is thus also to be transferred to the second data acquisition unit 130b and read by it.

[0039] Preferably, the first and second data acquisition units 130a, 130b are constructed identically, as follows. Both, i.e., the first and / or the second, data acquisition units 130a, 130b are equipped with a communication module 136 with a corresponding antenna unit, so that the vehicles 10, 20 can participate in the various types of vehicle-to-infrastructure (V2X) communication. Fig. 1 shows that the vehicle 10 can communicate with the mobile radio base station 210 of a mobile radio provider.

[0040] Such a base station 210 may be an eNodeB base station of an LTE (Long Term Evolution) or 5G (5th Generation Mobile System) mobile operator. The base station 210 and the corresponding equipment are part of a mobile communications network with a plurality of mobile radio cells, each cell being served by a base station 210.

[0041] The base station 210 is typically located near a main road on which the vehicles 10, 20 travel. The communication module of the data acquisition units 130a, 130b corresponds to an LTE communication module, with which the vehicles 10, 20 can receive mobile data (downlink) and transmit such data in the uplink direction. They send the data to the base station 210 via the so-called Uu-Link. In relation to the LTE mobile communication system, the Evolved UMTS Terrestrial Radio Access network E-UTRAN of LTE consists of several eNodeBs 210 that provide the E-UTRA user plane (PDCP / RLC / MAC / PHY) and the control plane (RRC). The eNodeBs 210 are interconnected via the so-called X2 interface. The eNodeBs are also connected to the EPC (Evolved Packet Core) 200 via the so-called S1 interface. V2X communication is also supported by the 5th generation of mobile communications systems.

[0042] From this general architecture, Fig. 1 that the base station 210 is connected to the EPC 200 via the S1 interface, and the EPC 200 is connected to the Internet 300. A backend server 320, to which the vehicles 10, 20 can send and receive messages, is also connected to the Internet 300. The backend server 320 can be located in a data center of the vehicle manufacturer or a system provider for the vehicle manufacturer, or in a data center of an authority, e.g., a traffic control center. Finally, a road infrastructure station 310 is also shown. This can be illustrated, for example, by a roadside unit, often referred to in technical jargon as a "roadside unit" (RSU) 310. The road infrastructure station 310 can be connected directly to the Internet 300. Communication between the vehicle 10, 20 and the road infrastructure station 310 can take place via the WLAN p system or another local radio network.To simplify implementation, it is assumed that all components have been assigned an internet address, typically in the form of an IPv6 address, so that the packets transporting messages between the components can be routed accordingly. The various interfaces mentioned are standardized. Reference is made to the relevant published specifications of the mobile communications system.

[0043] Fig. 2 shows a schematic block diagram of the on-board electronics as well as the pneumatic equipment of the trailer vehicle 20. As mentioned, the trailer vehicle 20 is equipped with a compressed air braking system DBS. Fig. 2 shows the more precise structure of the braking architecture of the trailer 10. Shown is a semi-trailer with only one axle, which is also referred to as a semi-trailer. This is just one example of a trailer vehicle 20 equipped with compressed air brakes. However, as described, various other trailer types can be equipped with pneumatic, hydraulic or electric braking systems. The reference number 100 denotes an EBS control unit (Electronic Braking System). The EBS control unit 100 is connected to a brake modulator which modulates the braking pressure in the compressed air brakes on the wheels 115 so that the wheels 115 do not lock during braking. This can prevent the trailer 10 from skidding. In addition, an IMU measuring unit 116, corresponding to an Inertial Measurement Unit, is connected to the EBS control unit 100. This contains a number of acceleration sensors and, if applicable.Angular rate sensors detect the movement of the trailer vehicle 20 for a number of degrees of freedom. This allows the EBS control unit 100 to also perform the ESC (Electronic Stability Control) function. This function corresponds to an electronic stability control system. Targeted braking of individual wheels 115 prevents the vehicle from skidding in corners at the limit, both during oversteering and understeering.

[0044] Reference number 112 designates the aforementioned Tristop cylinders, which, during normal operation, actuate the brake shoes of the wheel brake via a linkage and, during decoupled operation, actuate the spring-loaded parking brake FSFB according to the specified brake pressure. Wheel speed sensors 114 are also mounted on the wheels 115, which detect the rotational movement of the wheels 115. There are two compressed air lines 102, 104 connected to the towing vehicle 10. One line is referred to as the supply line and serves to supply compressed air to the trailer 10. The corresponding connection is provided with the reference number 102. The corresponding line is color-coded for easier identification. It is usually red. This supply line is routed to the park-release safety valve 110 and from there also leads to the compressed air reservoir 106 of the trailer 10.From there, the supply line leads to the modulator of the EBS control unit 100 and then to an overload protection valve 108. The second compressed air line is referred to as the brake line and serves to transmit the brake pressure as specified by the driver of the towing vehicle 11 by depressing the brake pedal. The corresponding connection of the brake pressure line on the trailer 10 is designated by reference number 104. This line also leads via the park release safety valve 110 to the overload protection valve 108 and from there to the Tristop cylinders 112 and to the modulator of the ESP control unit 100.

[0045] There are also electrical connections between the trailer vehicle 20 and the towing vehicle 10. Reference numeral 118 denotes a diagnostic line. A diagnostic device can be connected via this line, which can be used to read the error memory of the EBS control unit 100. Reference numeral 120 denotes a CAN bus line. Control commands are transmitted from the towing vehicle 10 to the EBS control unit 100 via this line. Finally, reference numeral 122 denotes a power supply line. The trailer vehicles 20 are typically not equipped with their own power supply.

[0046] The compressed air brake system DBS of the trailer vehicle 20 consists of the components EBS control unit 100, the connection 102 for the compressed air supply line, the compressed air supply line 103, the connection 104 for the brake pressure line, the brake pressure line 105, the compressed air reservoir 106, the overload protection valve 108, the parking release safety valve 110, the tri-stop cylinder 112, and the speed sensor 114.

[0047] The spring-loaded parking brake FSFB consists of the following components: connection 102 for the compressed air supply line, compressed air supply line 103, compressed air reservoir 106, overload protection valve 108, parking release safety valve 110, and Tristop cylinder 112. During normal operation, the service brake is actuated via Tristop cylinder 112. The brake pressure applied to Tristop brake cylinder 112 is measured by pressure sensor 124. The first data acquisition device of the trailer vehicle (20) is designated by reference number 130a. It is connected to communication bus 120, e.g., CAN bus. The first data acquisition device 130a records the time series of the pressure values measured by pressure sensors 124. For this purpose, these measured values together with the recorded measuring times are transmitted via the CAN bus 120 to the first data acquisition device 130a.Likewise, the wheel speed values measured by the wheel speed sensors 114 are transmitted to the data acquisition device 130a together with the measurement times. Fig. 2 also shows a rough block diagram of the first data acquisition device 130a. Reference numeral 132 denotes a storage unit. This can be a non-volatile storage unit in the form of an SD memory card, a USB flash drive, an SSD hard drive, or an HDD hard drive, etc. A CMOS RAM storage unit is also suitable.

[0048] The data exchange between towing vehicle 10 and trailer vehicle 20 is specified in the CAN bus standard. For precise details on the transmission protocol, refer to the ISO 11992-2 (High-Speed CAN) specification. Data is continuously exchanged via this bus. In the example considered, towing vehicle 10 sends CAN messages of the type "brake request inactive" and "brake request active, the deceleration request is at the value XY." The message formats for communication between the control units in towing vehicle 10 via the CAN bus are specified in the SAE J1939 standard. However, not all vehicle manufacturers adhere to this standard; instead, proprietary message formats are often specified by the vehicle manufacturers. A brake system manufacturer for trailer vehicles must also adhere to the message formats specified in the ISO 11992 standard, which, however, also binds the towing vehicle manufacturer.

[0049] During test drives, the braking behavior of trailer vehicle 20 is to be tested. For this purpose, measured values are recorded in the first data acquisition unit 130a, which is connected to the CAN bus 120 in the trailer vehicle 20. Such first and / or second data acquisition units 130a, 130b are available for purchase. They are often referred to by various suppliers as data loggers or telematics units. The first data acquisition unit 130a receives the messages transmitted on the CAN bus 120. As in the example of Fig. 2 , the sensors 114, 124 may not be directly connected to the CAN bus 120. Nevertheless, the EBS control unit 100 transmits their measured values via the CAN bus 120 to the towing vehicle 10 so that they can be recorded by the first data acquisition unit 130a.

[0050] Such CAN bus messages have a rough message format, as in Fig. 3 shown. It is divided into two parts: the first part transmits a message identifier (ID), and the second part transmits the payload data. The message identifier (ID) identifies the content of the data transmitted with the message and determines the message's priority during bus arbitration. The CAN bus uses a bus access method based on the CSMA / CR method, corresponding to "Carrier Sense Multiple Access / Collision Resolution." The brake system manufacturer knows the messages used to transmit the sensor data. This allows for a basic assignment to the message content. This is utilized in the first data acquisition unit 130a. The messages containing the data of interest can be filtered out using the message identifier. The precise parameter values are then contained in the message part of the message. This data can be stored in the first data acquisition unit 130a.The time information about the measurement time is typically not transmitted via the CAN bus 120. Therefore, it is necessary for the first data acquisition unit 130a to note the times of arrival of the respective messages in the data series by its own clock and / or with a time stamp.

[0051] One problem, however, is that the manufacturers of the data acquisition units 130a, 130b are not aware of the identifier ID, nor of the regulations and / or calculation rules for message interpretation, which can vary from manufacturer to manufacturer. Thus, fixed programming of the data acquisition units 130a, 130b is not easily possible for the manufacturer of the data acquisition units 130a, 130b.

[0052] Therefore, according to the invention, a programmable data acquisition unit 130a, 130b is proposed. As mentioned, the first and second data acquisition units can be operated independently of one another and have an identical structure. The following explains how the first and second data acquisition units 130a and 130b can be configured. Only the first data acquisition unit 130a is discussed as an example. For this purpose, a configuration message CANCB is transmitted to the data acquisition unit 130a. This can preferably be done via the air interface, i.e., the communication module 134. The configuration message CANCB would then be generated by the experts who are also interested in the test results and are located, for example, where the backend server 320 is located, and would also be transmitted to the trailer vehicle 20 via mobile radio or WLAN p.As an example, a configuration message could be transmitted to trailer vehicle 20 in JSON or XML format. The payload part of this message would contain the desired message identifiers (ID) to be captured, as well as the rules for interpreting the payload data in the desired CAN message CANB for pre-analysis, and the rule for when the data should be collected. This can be either time-based or event-based. The configuration message CANCB thus determines which data is used to compile the data series (DR).

[0053] A rule for interpreting payload data could, for example, be: "Take the first character of messages with identifier XY, multiply it by a scaling factor, add an offset, and interpret it as an integer." To interpret the payload data in the received message, this rule would be observed, and the corresponding measured values would be entered into the data series. Another example of interpretation rules at the bit level is: "For messages with ID=0xAABB, take byte 1 and evaluate bit 2."

[0054] At the byte level: "For messages with ID=0xAABB, determine the value of bytes 1 and 2, convert it using a scaling factor, and add an offset to obtain the physical value for interpretation." This corresponds to a rule for converting integers to floating-point numbers. Furthermore, the significance of the bits / bytes can be specified. Two options are possible here: sorting from right to left ("little endian"), with the lowest significant byte first, and sorting from left to right ("big endian"), with the most significant byte first. The type of number representation, e.g., integer or floating-point, can also be part of the rule.

[0055] Fig. 4 shows a concrete numerical example of a measurement series for the operating pressure, measured by pressure sensor 124. Twelve measured values are listed. The first column contains the consecutive number DR1 of the measured values. The second column shows the date and time of measurement DR2 of the respective measured value. The third column shows a brake status DR3. The number 1 means that the service brake was operating normally. The fourth column contains the peripheral speed DR4 of a wheel measured at the same time, measured in m / s. The fifth column lists the brake pressure DR5 measured in bar. The sixth column lists the relative brake pressure change DR6 compared to the previous measured value. This information is dimensionless and is calculated using a calculation rule that is explained in more detail below.Finally, the last column lists a mark DR7, which is linked to the values in the fifth column and indicates whether the measured value change is below a minimum value. This information is used to more quickly locate the constant brake pressure range DR5.

[0056] The figures contained in the sixth and last column of the table are calculated by a preliminary analysis of the measured values in the fourth and fifth columns. For this purpose, a computer program is used which is calculated in the computing unit 134 of the first data acquisition device 130a and whose flow chart is shown in Fig. 5 The computer program of the Fig.5 can be run after the test drive has ended or even in the background during the test drive. The program start is designated with reference symbol P1 and the word "Start". In program step P2 with the word "Calculate relative change of measured values", the relative change of the recorded measured values for the brake pressure is calculated. The resulting values are shown in column RBDAE of the table of Fig. 3 listed. In program step P2, the relative change of the pressure value to the previous value is determined and entered in the RBDAE column. The calculation rule consists of calculating the ratio between the subsequent value and the previous value and subtracting 1 from the result. The relative change between the values in rows 3 and 4 of column 5 would be calculated as follows: 4.3 / 3.4 - 1 = 0.2647. This results in the numerical values in column RBDAE. In the next program step P3 with the specification "Def. Mark := "True" for rel. change <= RFW", the values are analyzed with regard to the relative change, and an entry is made in the "Mark" column of the table in Fig. 3 set. The entry indicates whether the relative change is relatively small. If so, the entry "True" is entered as the mark. If the relative change is greater than the previous value, the mark "False" is entered as the mark. This measure allows the interesting range of relatively constant brake pressure to be found more quickly. As an example, a value of + / -10% is set as the limit for the maximum permitted relative change. If this limit is set to the values in column RBDAE in the table of Fig. 3 If the "True" entry is used, the "True" entry is first placed in line 4 and last in line 10. In program step P4 with the statement "Count number of "True" entries per range with RDZ ≠ 0," a preliminary analysis of the recorded data series DR is performed. This can be easily performed by examining the entries in the "Mark" column. The number of "True" entries per "True" range is counted where the measured peripheral speed is not zero. There may be several such ranges in the recorded data series. The test engineers are interested in the longest, constant pressure curve during a braking operation and in the deceleration of the vehicle in this range. This range corresponds to the range with the maximum number of "True" entries in the table where the peripheral speed is not zero.The data for the range determined in step P4 is selected in program step P5 with the instruction "Select the maximum range" and compiled as a payload packet for transmission to the backend server 320. In program step P6 with the instruction "Transfer the selected maximum range to the backend," the prepared payload packet is forwarded to the communication module 136. In the communication module 136, the payload packet is supplemented with the necessary protocol data such as error protection and address information, etc., and then transmitted to the backend server. The program ends after forwarding the payload packet to the communication module 136 in program step P7 with the instruction "End."

[0057] Fig. 6 shows the series of measured values in the table of Fig. 3 in graphical representation. The reference symbol BD denotes the curve for the measured brake pressure DR5. The reference symbol RBDAE denotes the calculated relative change DR6 of the brake pressure DR5. The reference symbol RDZ denotes the peripheral speed of the measured wheel 115. Finally, KBDB denotes the range of interest of relatively constant brake pressure DR5 for the linear deceleration, where the relative change DR6 of the brake pressure corresponds to + / -10% of the previously measured brake pressure value DR5. The measured values in this range are marked with the entry "True". In the example of Fig. 6 Selecting the area to be extracted is particularly easy because there is only one area with "True" entries set.

[0058] Fig. 7 shows the graphical representation of a data series DR in which there are several ranges with constant brake pressure DR5. In this case, the longest lasting range with a moving vehicle 20 is selected. The standstill range could include a range in which the wheels 115 lock during the braking process, so that this range could also be of interest for another target. Especially with the Fig. 7 It is clearly visible that the KBDB area represents only approximately 10% of the data volume compared to the entire DR data series. The advantage of this type of preprocessing is that significantly less data needs to be transferred to the backend server 320, and significantly less data needs to be stored and evaluated in the backend. In real test drives, the advantage could be even greater, because, for example, only 1% of the data needs to be transferred.

[0059] All examples and conditional language mentioned herein are to be understood without limitation to such specifically cited examples. For example, it will be appreciated by those skilled in the art that the block diagram presented herein represents a conceptual view of an exemplary circuit arrangement. Similarly, it will be appreciated that a depicted flowchart, state transition diagram, pseudocode, and the like represent various variations for representing processes that can be substantially stored in computer-readable media and thus executed by a computer or processor. The object recited in the claims may also expressly be a person.

[0060] It should be understood that the proposed method and associated devices can be implemented in various forms of hardware, software, firmware, special-purpose processors, or a combination thereof. Special-purpose processors may include application-specific integrated circuits (ASICs), reduced instruction set computers (RISCs), and / or field-programmable gate arrays (FPGAs). Preferably, the proposed method and device are implemented as a combination of hardware and software. The software is preferably installed as an application program on a program storage device. Typically, this is a computer platform-based machine that includes hardware such as one or more central processing units (CPUs), random access memory (RAM), and one or more input / output (I / O) interfaces. An operating system is also typically installed on the computer platform.The various processes and functions described here may be part of the application program or a part executed by the operating system.

[0061] The disclosure is not limited to the embodiments described herein. There is room for various adaptations and modifications that a person skilled in the art would consider based on their technical knowledge and the disclosure.

[0062] The aggregation function presented here is based on the assumption that a data series can be reduced to a characteristic range, yet still allow a technical assessment of the system state—here: pressure profile and delay. However, the data aggregation principle presented here can be generalized and applied to various other applications and data series.

[0063] Further examples of control units in vehicles that can also be tested or monitored using the data acquisition device according to the invention include: airbag control units, engine control units, transmission control units, chassis control units, as well as various control units for assistance systems: emergency braking assistant, ESC (Electronic Stability Control), lane keeping or lane change assistant, turning assistant, adaptive cruise control assistant, distance warning assistant, parking assistant, etc. The environment detection sensors required for this (lidar, radar, ultrasound, as well as various types of cameras) can also be dynamically evaluated. It is particularly advantageous for these sensors to filter the output data, as the data volumes are much larger than for the various control units. Data aggregation can be used for the environment detection sensors, for example,For dynamic message interpretation, an externally installed roadside unit 310 sends a message to the data acquisition system with the command as to when the images captured by the camera should be sent to the backend server 320. This message could be sent by the roadside unit 310 when the test vehicle is at a certain distance from the traffic sign.

[0064] The data acquisition unit according to the invention can be used particularly for test drives during the development of vehicle systems. However, such data acquisition units can also be used in production vehicles to monitor data bus traffic within the vehicle and detect tampering or error conditions.

[0065] For example, one could automatically capture images of gas station prices in an application outside of test tracks. However, this would require the navigation system to send the corresponding command specifying when the data should be transmitted to the backend server 320. Another example concerns fleet management, for example, in logistics companies. With dynamic message interpretation, the controllers could then define their own data packets that are important for accountability. For example, a message could read: "How often did the lane departure warning system intervene to prevent an unintentional lane change?" This data could be transmitted to the backend server 320 from time to time. List of reference symbols (part of the description)

[0066] 10Towing vehicle 20Trailer vehicle 100Brake control unit 102Compressed air supply line connection 103Compressed air supply line 104Brake pressure line connection 105Brake pressure line 106Compressed air reservoir 108Overload protection valve 110Park release safety valve 112Tristop brake cylinder 114Wheel speed sensor 115Wheel 116IMU unit 118Diagnostic line 120Communication bus 122Power supply line 124Pressure sensor 130aFirst data acquisition device 130bSecond data acquisition device 131CAN bus interface 132Storage unit 134Computing unit 136Communication module 200Evolved Packet Core 210Mobile radio base station 300Internet 310Roadside unit 320Backend server BDBrake pressure curve CANBCAN message CANCBConfiguration message DBSAir brake system consisting of components 100 - 114 DR1Consecutive number DR2Measurement time DR3Brake status DR4Circumferential speed DR5Brake pressure DR6Relative brake pressure change DR7Brand FSBFSpring-loaded parking brake consisting of components 102, 103, 106, 108,110, 112 IDMessage identifier KBDBRange of constant brake pressure PLUser data RBDAEVariability of the relative brake pressure change RDZWheel speed progression RFWReference value P1 - P7various program steps of a computer program,

Claims

1. Data acquisition device (130a, 130b) for mobile devices (10, 20), comprising a computing unit (134) and a storage unit (132), further comprising a communication module (136) for sending acquired data (DR4, DR5) to a backend server (320), and a bus interface (131) for receiving messages (CANB) that are transmitted via an internal communication bus (120) of the mobile device (10, 20), the computing unit (134) being configured to form a data series (DR) with the data (DR4, DR5) received in the messages (CANB), the computing unit (134) being configured to store the data series in the storage unit (132), the computing unit (134) being designed to carry out a preliminary analysis of the stored data series (DR) in the form of a data aggregation (P1 - P7), in which at least one region (KBDB) of interest of the data series (DR) is extracted and forwarded to the communication module (136), the communication module (136) being configured to transmit the at least one extracted region (KBDB) of the data series (DR) to the backend server (320), characterized in that the data aggregation (P1-P7) for extracting the region of interest includes a step (P2) of calculating the relative change (DR6) of a datum (DR5) in the data series (DR) compared to the previous datum in the data series and a step (P3) of assigning a marking (DR7) to a datum (DR5) in the data series (DR), the marking (DR7) being assigned to the particular nth datum (DR5) if the relative change (DR6) of the nth datum (DR5) in the data series (DR) compared to the n-1st datum (DR5) in the data series (DR), with n element of a natural number, is smaller than a minimum permissible reference value (RFW), the data aggregation (P1 - P7) including a step (P4) of counting the immediately consecutive marked data (DR4, DR5) in the data series (DR) at which the mobile device (10, 20) is still moving, the data aggregation (P1 - P7) including a step of determining the region (KBDB) in the data series (DR) in which a maximum number of immediately consecutive data (DR4, DR5) with the set marking (DR7) is contained, the communication module (136) being designed to send the region (KBDB) of the data series (DR) with the maximum number of immediately consecutive data (DR4, DR5) with the set marking (DR7) to the backend server (320).

2. Data acquisition device (130a, 130b) according to claim 1, wherein the computing unit (134) is designed to note the times (DR2) of reception of the received messages (CANB) in the data series (DR) in the data (DR4, DR5) of the particular received message (CANB).

3. Data acquisition device (130a, 130b) according to claim 1 or 2, wherein the communication module (136) is configured to receive at least one configuration message (CANCB), wherein the at least one configuration message (CANCB) contains a specification as to how the data (DR4, DR5) of a message (CANB) transmitted via the internal communication bus (120) are to be evaluated.

4. Data acquisition device (130a, 130b) according to claim 3, wherein the computing unit (134) is designed to compile the data series (DR) with the data (DR4, DR5) of the received messages (CANB) in accordance with the specification from the at least one configuration message (CANCB).

5. Data acquisition device (130a, 130b) according to any of the preceding claims, wherein the acquired data (DR4, DR5) relate to data (DR4, DR5) measured by sensors (114, 124) or data (DR6) calculated by computing units (100).

6. Data acquisition device (130a, 130b) according to any of the preceding claims, wherein the mobile device is a vehicle (10, 20) and the internal communication bus (120) is designed as a CAN bus of the vehicle (10, 20), corresponding to controller area network.

7. Data acquisition device (130a,) according to claim 6, wherein the vehicle corresponds to a towing vehicle (10) or a trailer vehicle (20) and the trailer vehicle (20) is equipped with a braking system (DBS).

8. Data acquisition device (130a) according to claim 7, wherein a brake control unit (100) is connected to the internal CAN bus (120) of the trailer vehicle (20), which brake control unit transmits, via the CAN bus, the data (DR4, DR5) from a number of brake pressure sensors (124) and / or wheel speed sensors (114) connected to the brake control unit (100).

9. Data acquisition device (130a) according to claim 8, wherein the specification in the at least one configuration message (CANCB) includes at least the message identifier (ID) of the CAN message (CANB) with which the measured brake pressure (DR5) of a brake pressure sensor (124) is transmitted and / or an indication of the minimum relative brake pressure change (DR6) that is still tolerable compared to the immediately preceding brake pressure value (DR5) in the data series (DR) in order to be able to assign the brake pressure value (DR5) to a region (KBDB) of relatively constant brake pressure (DR5).

10. Data acquisition device (130a) according to claim 8 or 9, wherein the specification in the at least one configuration message (CANCB) includes at least the message identifier (ID) of the CAN message (CANB) with which information (DR4) of a wheel speed sensor (124) is transmitted.

11. Method for carrying out a preliminary analysis in a data acquisition device (130a) according to any of the preceding claims, a data series (DR) being formed from data in messages (CANB) transmitted via an internal communication bus of a mobile device, the preliminary analysis fulfilling the function of a data aggregation (P1 - P7), characterized in that the data aggregation (P1-P7) includes a step (P2) of calculating the relative change (DR6) of the data (DR5) in the data series (DR) and a step (P3) of assigning a marking (DR7) to a datum (DR5) in the data series (DR), the marking (DR7) being assigned to the particular datum (DR5) if the relative change (DR6) of the nth datum (DR5) in the data series (DR) compared to the n-1st datum (DR5) in the data series (DR), with n element of a natural number, is smaller than a minimum permissible reference value (RFW), the data aggregation (P1 - P7) including a step (P4) of counting the immediately consecutive marked data (DR4, DR5) in the data series (DR) at which the mobile device (10, 20) is still moving, the data aggregation (P1 - P7) including a step of determining the region (KBDB) in the data series (DR) in which the maximum number of immediately consecutive data (DR4, DR5) with the set marking (DR7) is contained, the region (KBDB) of the data series (DR) with the maximum number of immediately consecutive data (DR4, DR5) with the set marking (DR7) being sent to a backend server (320).

12. Vehicle, characterized in that the vehicle (10, 20) is equipped with a device (130a) according to any of claims 1 to 10, in particular for carrying out a method according to claim 11, the vehicle corresponding to the mobile device.

13. Computer program, characterized in that the computer program is designed to carry out the steps of the method according to claim 11 when processed in a computing unit (134).