Method and apparatus for determining information of a bus system

Abstract

Device and method for determining information of a bus system, in particular computer-implemented method, the bus system having a transmission medium via which signals can be transmitted, the method comprising: determining a first variable characterizing a time difference between a first point in time and a second point in time, wherein at the first point in time a signal output by a sender onto the transmission medium of the bus system reaches a first location with respect to the transmission medium, wherein at the second point in time a signal output by the sender onto the transmission medium of the bus system reaches a second location with respect to the transmission medium, evaluating the first variable, wherein for determining the first variable at least one time-to-digital converter device is used.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a method for determining information of a bus system.

[0002] The present disclosure also relates to a device for determining information of a bus system. SUMMARY

[0003] An exemplary embodiment relates to a method, in particular a computer-implemented method, for determining information of a bus system, the bus system having a transmission medium via which a signal can be transmitted, the method comprising: determining a first variable characterizing a time difference between a first point in time and a second point in time, wherein at the first point in time a signal output by a sender onto the transmission medium of the bus system reaches a first location with respect to the transmission medium, wherein at the second point in time a signal output by the sender onto the transmission medium of the bus system reaches a second location with respect to the transmission medium, evaluating the first variable, wherein for determining the first variable at least one time-to-digital converter device is used, for example. In a further exemplary embodiment, this enables a particularly efficient determination of the first variable.

[0004] In other words, in an exemplary embodiment, the first variable characterizes a time difference between a signal output by a sender or the sender onto a transmission medium of the bus system reaching a first location with respect to the transmission medium or the first location and a signal output by a sender or the sender onto a transmission medium of the bus system reaching a second location with respect to the transmission medium or the second location. In a further exemplary embodiment, the first variable can also be referred to as a propagation difference or a propagation time difference.

[0005] For example, the first location is different from the second location. Furthermore, for example, a location of the sender is different from the first location and the second location.

[0006] In a further exemplary embodiment, as an alternative or in addition to a time-to-digital converter device, other devices can be used for determining the first variable, which in a further exemplary embodiment can also be configured as a hardware circuit or a (discrete) logic circuit, for example.

[0007] In a further exemplary embodiment, the bus system has one of the following types: CAN, CAN FD, CAN XL, 10BASET1S, LIN, FlexRay, MOST, KNX, LSN, ARINC bus, MIL bus, other types.

[0008] In further exemplary embodiments, the method further comprises at least temporarily connecting a first input (e.g. a START input) of the time-to-digital converter device with the transmission medium at the first location and at least temporarily connecting a second input (e.g. a STOP input) of the time-to-digital converter device with the transmission medium at the second location.

[0009] In further exemplary embodiments, the time-to-digital converter device is configured to determine a time difference between a state change of an input signal at a first input (e.g. a START input) and a state change of an input signal at a second input (e.g. a STOP input) and to output information representing the time difference, e.g. via a digital interface or as a digital value.

[0010] In further exemplary embodiments, the state change of an input signal at the first input and / or at the second input is a rising edge, e.g. a rising edge of a corresponding pulse, or a falling edge, or another perceivable change of the input signal.

[0011] In further exemplary embodiments, the state change of an input signal of the time-to-digital converter device can also use, for example, a rising edge of a signal transmitted via the bus system. In further exemplary embodiments, this signal can also be associated with a message transmitted via the bus system, for example. The signal can represent at least a portion of the message, for example.

[0012] In further exemplary embodiments, at least two time-to-digital converter devices are used to determine the first variable. Thereby, a further degree of freedom is created in determining the first variable.

[0013] In a further exemplary embodiment, the method further comprises outputting a common start signal to the first time-to-digital converter device and to the second time-to-digital converter device, at least temporarily connecting a second input (e.g. a stop input) of the first time-to-digital converter device to the transmission medium at the first location, and at least temporarily connecting a second input (e.g. a stop input) of the second time-to-digital converter device to the transmission medium at the second location. Thereby, the common start signal can be applied to the first and second time-to-digital converter device at the same time, while the corresponding signal on the transmission medium at the first or second location can be used as a stop signal. In other words, in a further exemplary embodiment, the first time-to-digital converter device can be used to determine a transit time of a signal from a time point of the start signal to the first location, and the second time-to-digital converter device can be used to determine a transit time of a signal or of the signal (e.g. the same signal) from the time point of the start signal to the second location. For example, the first variable can be determined from the time difference which can be determined by means of the respective time-to-digital converter device.

[0014] In a further exemplary embodiment, the method further comprises determining a model and / or reference data of at least one sender which can be connected to the transmission medium at a predefinable location, wherein for example the model and / or the reference data characterize a first variable of the at least one sender.

[0015] In a further exemplary embodiment, for example for a predefinable bus system having a number of bus users which at least temporarily also work as senders, the respective first variable can be determined for the bus users, i.e. for example their signal propagation time difference with respect to the first and second locations described above. For this purpose, the bus users can each send for example at least one predefinable message via the bus system, which message arriving at the first and second locations can be used as a start signal or as a stop signal for the respective input of the at least one time-to-digital converter device.

[0016] In a further exemplary embodiment, the determination of the first variable can for example take place in a safety-relevant environment, for example in a manufacturing device or in a plant. Thereby, it is ensured that the determined first variable or propagation time difference is correct and for example not manipulated.

[0017] In further exemplary embodiments, the first variable can also be determined, for example, outside of the secure environment, for example, using a cryptographically protected (for example, digitally signed by a bus user or (at least partially) encrypted) message. In further exemplary embodiments, the optional evaluation of at least a portion of the message content can thus ensure that the signal or the message in question actually originates from the respective bus user and not, for example, from an attacker who has connected to the bus system without authorization (and / or who has manipulated an existing bus user).

[0018] In further exemplary embodiments, the model of the at least one sender or bus user can have, for example, a value of the first variable determined in the manner described above. In further exemplary embodiments, the model can thus assign a corresponding value of the first variable to a plurality of senders or bus users, respectively. In further exemplary embodiments, the model can later, for example, when the bus system is in operation in the field (for example, installed in a target system such as a vehicle (for example, a motor vehicle)), be used to compare a first variable value determined in the field with a first variable value from the model. If the two values are at least substantially identical (i.e., for example, differ from each other by at most a predefinable measure), it can be concluded in further exemplary embodiments that a) the bus user or sender in question actually corresponds to the bus user or sender used to form the model, and / or b) the bus user or sender in question is arranged at the same position of the transmission medium as the bus user or sender used to form the model.

[0019] In further exemplary embodiments, the model can have a unique or one-to-one assignment of the first variable to the respective bus user, which can be implemented, for example, by means of a table.

[0020] In further exemplary embodiments, the model can have a probability distribution, for example, specifying for at least one bus user which value of the first variable of the bus user in question is expected with what probability.

[0021] In further exemplary embodiments, the model can have a graph or tree, for example, a decision tree.

[0022] In further exemplary embodiments, it is provided that the evaluation of the first variable comprises determining a position of the sender, for example, with respect to the transmission medium, based on the first variable, and / or comparing the first variable with the model or the reference data. For example, in further exemplary embodiments, the comparison can comprise a comparison of the first variable currently determined with a first variable value from the model or the reference data.

[0023] In further exemplary embodiments it is provided that the method further comprises evaluating the information characterized by the signal, for example extracting information from a message characterized by the signal. In other words, in further exemplary embodiments the signal can be used, in addition to controlling the start input and / or the stop input of a time-to-digital converter arrangement for example, at least partially to determine a message content of a message associated with or characterized by the signal, for example a CAN identifier in the case of a CAN bus system.

[0024] In further exemplary embodiments it is provided that the method further comprises determining, based on the information and the first variable, whether the sender of the signal is a device authorized to communicate via the bus system. In further exemplary embodiments, for this purpose optionally for example a digitally signed or encrypted message or parts of a message are used, which for example are difficult or impossible to forge for an attacker.

[0025] In further exemplary embodiments it is provided that, when it has been determined that the sender of the signal is not a device authorized to communicate via the bus system, for example because a digital signature is not present or is invalid and / or because the first variable G1 cannot be assigned to an authorized device, for example an authorized bus user, at least one countermeasure is initiated, the purpose of which is for example to block the transmission of the sender and / or to declare the transmission invalid.

[0026] In further exemplary embodiments, for example in the case of a CAN bus system, the transmission of for example an unauthorized sender can be blocked by sending an error data frame and / or by occupying the bus system, for example by repeatedly sending messages with a higher priority by a bus user or a device executing the method according to an embodiment.

[0027] In further exemplary embodiments, for example when the method is implemented on a system connecting multiple bus systems, malicious messages can not be forwarded. In other words, in further exemplary embodiments the transmission of an unauthorized sender can be limited or blocked, for example by not forwarding the corresponding messages of the transmission from the first bus system in which they occur to other bus systems.

[0028] Further exemplary embodiments relate to a device for executing a method according to an embodiment. For example, the device can be configured as a control device, for example for a motor vehicle, or can be integrated into a control device, for example for a motor vehicle.

[0029] Further exemplary embodiments relate to a computer-readable storage medium comprising instructions which, when executed by a computer, cause the computer to execute a method according to an embodiment.

[0030] A further exemplary embodiment relates to a computer program comprising instructions which, when the program is executed by a computer, cause the computer to carry out the method according to the exemplary embodiments.

[0031] A further exemplary embodiment relates to a data carrier signal which transmits and / or characterizes a computer program according to the exemplary embodiments.

[0032] A further exemplary embodiment relates to the use of the method according to the exemplary embodiments and / or the device according to the exemplary embodiments and / or the computer-readable storage medium according to the exemplary embodiments and / or the computer program according to the exemplary embodiments and / or the data carrier signal according to the exemplary embodiments for at least one of the following elements: a) determining a position of a sender of the bus system, b) checking a position of a sender of the bus system, c) providing an intrusion detection system and / or an intrusion detection and prevention system, d) authenticating a sender of the bus system.

[0033] Further features, possibilities of application and advantages of the present application result from the following description of exemplary embodiments of the present application, illustrated in the drawings. Herein, all features described or shown - individually or in any combination - form the subject of the present application, irrespective of their summary in the claims or their citation or display in the description or the drawings. BRIEF DESCRIPTION OF DRAWINGS

[0034] In the drawings:

[0035] Figure 1 schematically illustrates a simplified flow chart of a method according to exemplary embodiments,

[0036] Figure 2 schematically illustrates a simplified block diagram according to further exemplary embodiments,

[0037] Figure 3A schematically illustrates a simplified flow chart according to further exemplary embodiments,

[0038] Figure 3B schematically illustrates a simplified flow chart according to further exemplary embodiments,

[0039] Figure 4 schematically illustrates a simplified block diagram of a device according to further exemplary embodiments,

[0040] Figure 5 schematically illustrates a simplified block diagram according to further exemplary embodiments,

[0041] Figure 6 schematically illustrates a simplified timing diagram according to further exemplary embodiments,

[0042] Figure 7 schematically illustrates a simplified block diagram according to a further exemplary embodiment,

[0043] Figure 8 schematically illustrates a simplified block diagram according to a further exemplary embodiment, and

[0044] Figure 9 schematically illustrates an aspect of use according to a further exemplary embodiment. DETAILED DESCRIPTION

[0045] Figure 1 schematically illustrates a simplified flow chart of a method, in particular a computer-implemented method, for determining information of a bus system 10 (see Figure 2 ) having a transmission medium 11 via which a signal S can be transmitted, for example transmitted by a sender 5.

[0046] The method (see Figure 1 ) comprises determining 110 a first variable G1 which characterizes a time difference ZD between a first point in time tl and a second point in time t2, see also the exemplary timing diagram according to Figure 6 , wherein at the first point in time tl the signal S output by the sender 5 (see Figure 2 ) onto the transmission medium 11 of the bus system 10 reaches a first position pl (see Figure 2 ) with respect to the transmission medium 11, wherein at the second point in time t2 (see Figure 6 ) the signal S output by the sender 5 onto the transmission medium 11 of the bus system 10 reaches a second position p2 with respect to the transmission medium 11, evaluating 120 (see Figure 1 ) the first variable G1, wherein for determining 110 the first variable G1 at least one time-to-digital converter device 300, 300-1 (see Figure 2 ) is used. In a further exemplary embodiment, this enables a particularly efficient determination of the first variable G1.

[0047] In other words, in an exemplary embodiment, the first variable G1 characterizes a time difference between the signal S output by the sender or sender 5 (see Figure 2 ) onto the transmission medium 11 of the bus system 10 reaching a first position or first position pl with respect to the transmission medium and the signal S output by the sender or sender 5 onto the transmission medium 11 of the bus system 10 reaching a second position or second position p2 with respect to the transmission medium. In a further exemplary embodiment, the first variable can also be referred to as a propagation difference or a propagation time difference. In Figure 6 , the curve Kl exemplarily symbolizes a time course of a physical variable, for example a bus line 11a, 11b (see Figure 2The voltage between 5 and 6, the time change process is due to the voltage between the transmitter 5 and 6. Figure 2 The signal S sent is obtained from the first position p1, and Figure 6 Curve K2 in the figure exemplarily represents the time-varying process of a physical variable, such as the voltage between bus lines 11a and 11b. Figure 2 This time change process is due to the sender 5 ( Figure 2 The signal S sent is obtained from the second position p2. The time difference ZD between the first time point t1 and the second time point t2 can also be obtained from... Figure 6 This can be seen from the text.

[0048] For example, the first position p1 ( Figure 2 The position pS of the sender is different from the first position p1 and the second position p2. Furthermore, for example, the sender's position pS is different from the first position p1 and the second position p2. Figure 2 Arrows a1 and a2 in the diagram exemplarily indicate the signal path from the sender 5 that covers the first position p1 (arrow a1) or the second position p2 (arrow 2a).

[0049] In another exemplary embodiment, the bus system 10 has one of the following types: CAN, CAN FD, CANXL, 10BASET1S, LIN, FlexRay, MOST, KNX, LSN, ARINC bus, MIL bus, or other types.

[0050] In another exemplary embodiment, the transmission medium 11 is configured for the transmission of non-differential (“single-ended”) signals, see [reference]. Figure 2 In another exemplary embodiment, the transmission medium 11 is configured for the transmission of differential signals, see [reference needed]. Figure 5 And for this purpose, it can have, for example, two bus lines 11a and 11b.

[0051] In another exemplary embodiment, see Figure 3A The method includes: at least temporarily turning off the first input terminal 301 of the time-to-digital converter device 300 ( Figure 2 For example, the start input terminal is connected to the transmission medium 11 at the first position p1 by 130, and the second input terminal 302 (e.g., the stop input terminal) of the time-to-digital converter device 300 is connected to the transmission medium 11 at the second position p2 by 132 at least temporarily. Figure 3A ).

[0052] In another exemplary embodiment, the time-to-digital converter device 300 ( Figure 2 ) is configured to determine the first input terminal 301 ( Figure 2 For example, the input signal at the start input terminal (see example) Figure 6The state change of curve K1) and the input signal at the second input terminal 302 (e.g., the stop input terminal) (see example) Figure 6 The time difference ZD between the state changes of curve K2) Figure 6 ), and output information representing the time difference ZD, for example via digital interface 305 ( Figure 2 (or as a numerical value)

[0053] In another exemplary embodiment, the state change of the input signal at the first input terminal and / or the second input terminal is a rising edge, such as the rising edge of a corresponding pulse, for example, when the input signal in question exceeds a pre-given threshold SW. Figure 6 The rising edge is generated when ( ). Figure 2 Arrows a3 and a4 indicate that the corresponding input signals are transmitted from positions p1 and p2 (at least temporarily) to the input terminals 301 and 302 of the time-to-digital converter device 300.

[0054] In another exemplary implementation (not shown), the state change of the input signal at the first input terminal and / or the second input terminal may also be, for example, a falling edge, such as the falling edge of a corresponding pulse, or other perceptible or determinable change of the input signal. In these cases, for example, a value below or reaching a threshold may be used.

[0055] In another exemplary embodiment, the time-to-digital converter device 300 is selectively connected to the transmission medium 11 of the bus system 10, for example, when the method according to the embodiment should be performed.

[0056] In another exemplary embodiment, the time-to-digital converter device 300 is selectively disconnected from or not connected to the transmission medium 11 of the bus system 10, for example, when the method according to the embodiment should not be performed.

[0057] In another exemplary embodiment, the state change of the input signal of the time-to-digital converter device 300 may, for example, use the rising edge of the signal S transmitted via the bus system 10, as exemplarily in the present case, according to... Figure 6 As shown in curves K1 and K2. In another exemplary embodiment, signal S ( Figure 2 For example, it can also be associated with a message transmitted via bus system 10. For example, signal S can characterize at least a portion of a message (e.g., a CAN message in the case of CAN bus system 10).

[0058] In another exemplary embodiment, see Figure 2 The first variable G1 is determined using at least two time-to-digital converter devices 300-1 and 300-2. This results in further degrees of freedom in determining the first variable G1.

[0059] In another exemplary embodiment, see Figure 3B The method further includes: sending a common start signal S-start output 140 to a first time-to-digital converter device 300-1 ( Figure 2 The second time-to-digital converter device 300-2, at least temporarily connects the second input terminal 302 (e.g., the stop input terminal) of the first time-to-digital converter device 300-1 to the transmission medium 11 at the first position p1. Figure 2 ) connect 142 ( Figure 3B At least temporarily, the second input terminal 302 (e.g., stop input terminal) of the second time-to-digital converter device 300-2 is connected 144 to the transmission medium 11 at the second position p2. This allows a common start signal S-start to be applied simultaneously to the first and second time-to-digital converter devices 300-1 and 300-2, while the corresponding signals K1 and K2 on the transmission medium 11 at the first or second position... Figure 6 This can be used as a stop signal. In other words, in another exemplary embodiment, the first time-to-digital converter device 300-1 can be used to determine the time point t0 from which the signal S begins (starting from the start signal S-). Figure 6 The transit time from the start signal S to the first position p1 is determined, and the second time-to-digital converter device 300-2 can be used to determine the transit time of the signal or the signal S (e.g., the same signal) from the start time of the start signal S- to the second position p2. For example, the first variable G1 can be determined from the time difference, which can be determined by means of the corresponding time-to-digital converter devices 300-1, 300-2.

[0060] Figure 6 Arrows a6 and a7 in the image symbolize sender 5 ( Figure 2 The corresponding signal transit time between the corresponding time-to-digital converter devices 300-1 and 300-2. Conversely, Figure 6 Arrow a5 in the diagram symbolizes the signal transit time, for example, in the first curve K1 (the portion of signal S). Figure 2 This part can be determined at the first position p1) when the threshold SW is used as (e.g., the only) start signal of the time-to-digital converter device 300 and, for example, when the second curve K2 (the part of signal S) is used as the start signal of the time-to-digital converter device 300. Figure 2 (This part can be determined at the second position p2) When the threshold SW is used as a stop signal (e.g., the only) time-to-digital converter device 300, the transit time of the signal can be determined.

[0061] In another exemplary embodiment, see Figure 1 The method further includes: determining at least one transmitter 5 that can be connected to the transmission medium 11 at a pre-given location pS.Figure 2 ) and / or reference data RD, wherein the model M and / or reference data RD characterizes, for example, a first variable G1 of at least one sender 5.

[0062] In a further exemplary embodiment, for example for a predeterminable bus system 10 having a certain number of bus users which at least temporarily also work as senders 5, a respective first variable G1 can be determined for these bus users, i.e. for example their signal propagation time difference with respect to the above-described first and second positions pi, p2. For this purpose, these bus users can each send, via the bus system 10, for example at least one predeterminable message which, on arrival at the first and second positions pi, p2, can be used as a start signal or stop signal for the respective inputs 301, 302 of the at least one time-to-digital converter device 300.

[0063] In a further exemplary embodiment, the determination of the first variable (for example for the model M or reference data RD) can be carried out, for example, in a secure environment, for example of a manufacturing device or a plant. Thereby it is ensured that the determined first variable or propagation time difference is correct and, for example, not manipulated.

[0064] In a further exemplary embodiment, the first variable can also be determined, for example, outside a secure environment, wherein, for example, cryptographically protected (for example by bus user digital signature or (at least partial) encryption) messages are used. Thereby, in a further exemplary embodiment, by optional evaluation of at least a part of the message content it can be ensured that the signal S or the message in question actually originates from the respective bus user and not, for example, from an attacker who has connected to the bus system 10 (and / or manipulated an existing bus user 5) without authorization.

[0065] In a further exemplary embodiment, the model M of the at least one sender or bus user can have, for example, the above-described form (see, for example, Fig. 2), wherein, for example, the first variable G1 is determined by the model M and / or reference data RD. Figure 1value of the first variable determined in step 110). In further exemplary embodiments, the model M can thus assign a corresponding value of the first variable G1 to the plurality of senders or bus users, respectively. In further exemplary embodiments, the model M can later, e.g. when the bus system 10 is running in the field (e.g. installed in a target system such as a vehicle (e.g. a motor vehicle)), be used for comparing a value of the first variable G1 determined in the field with a value of the first variable G1 from the model M. If both values are at least substantially identical (i.e. e.g. differ from each other by at most a pre-given measure), it can be concluded in further exemplary embodiments that a) the bus user or sender 5 involved actually corresponds to the bus user or sender used for forming the model M, and / or b) the bus user or sender 5 involved is arranged at the same position pS of the transmission medium 11 as the bus user or sender used for forming the model M.

[0066] In further exemplary embodiments, the model M can have an e.g. unique or one-to-one assignment of the first variable G to the respective bus user, which can e.g. be implemented by means of a table.

[0067] In further exemplary embodiments, the model M can have a probability distribution, which e.g. states for at least one bus user with which probability which value of the first variable G1 of the bus user involved is expected.

[0068] In further exemplary embodiments, the model M can have a graph or tree, e.g. a decision tree.

[0069] In further exemplary embodiments (see Figure 1 ) it is provided that the evaluation 120 of the first variable G1 comprises determining 120a a position pS of the sender 5 based on the first variable G1, e.g. with respect to the transmission medium 11 (which position can e.g. correspond to a longitudinal coordinate of an exemplary one-dimensional view along the transmission medium 11), and / or comparing 120b the first variable G1 with the model M or the reference data RD. For example, in further exemplary embodiments, the comparison 120b can comprise a comparison of the first variable G1 currently determined with a value of the first variable G1 from the model M or the reference data RD, for example.

[0070] In further exemplary embodiments (see Figure 1 ) it is provided that the method further comprises evaluating 122 information I characterized by the signal S (see Figure 2 ) e.g. extracting information from the message characterized by the signal S. In other words, in further exemplary embodiments, the signal S is used for controlling an enable input and / or a stop input of the time-to-digital converter device 300 (see e.g. according to Figure 6the curve K1, K2), can also be used to at least partially determine the message content of a message associated with or characterized by the signal S (e.g. the CAN identifier in the case of a CAN bus system).

[0071] In further exemplary embodiments it is provided that the method further comprises determining 124 whether the sender 5 of the signal S is a device authorized to communicate via the bus system 10 based on the information I and the first variable G. In further exemplary embodiments, for this purpose optionally e.g. digitally signed or encrypted messages or parts of messages are used, which are e.g. difficult or impossible to forge for an attacker.

[0072] In further exemplary embodiments it is provided that when it has been determined that the sender 5 of the signal S is not a device authorized to communicate via the bus system 10 (e.g. because the digital signature is not present or invalid and / or because the first variable G1 cannot be assigned to an authorized device, e.g. an authorized bus user, e.g. the location pS derivable from the first variable G1 of the sender 5 does not coincide with a known location pre-given for authorized senders), at least one countermeasure is initiated, see step 126, the purpose of which is e.g. to block the transmission of the sender and / or to declare the transmission invalid and / or not to forward the transmission.

[0073] In further exemplary embodiments, e.g. in the case of a CAN bus system 10, the transmission of e.g. an unauthorized sender can be blocked by sending an error data frame and / or by occupying the bus system 10 (e.g. by repeatedly sending a message with higher priority by a bus user or a device executing the method according to the embodiments).

[0074] Further exemplary embodiments (see Figure 4 ) relate to a device 200 for executing the method according to the embodiments. For example, in further exemplary embodiments the device 200 can be configured as a control device, e.g. for a motor vehicle, or can be integrated into a control device, e.g. for a motor vehicle.

[0075] The device 200 has a computing device ("computer") 202 with at least one computing core 202a and a storage device 204 assigned to the computing device 202 for at least temporarily storing at least one of the following elements: a) data DAT (e.g. one or more first variables G1 and / or a model M or reference data RD and / or at least one message and / or information derivable or derivable therefrom), b) a computer program PRG, in particular for executing the method according to the embodiments.

[0076] In a further exemplary embodiment, the storage device 204 comprises a volatile memory 204a (e.g. a working memory (RAM)) and / or a non-volatile memory 204b (e.g. a flash memory EEPROM).

[0077] In a further exemplary embodiment, the computing device 202 has or is configured as at least one of a microprocessor (μP), a microcontroller (μC), an application-specific integrated circuit (ASIC), a system-on-chip (SoC), a programmable logic module (e.g. FPGA, field-programmable gate array), a hardware circuit, or any combination thereof.

[0078] A further exemplary embodiment relates to a computer-readable storage medium SM comprising instructions PRG which, when executed by the computer 202, cause the computer 202 to perform the method according to the embodiments.

[0079] A further exemplary embodiment relates to a computer program PRG comprising instructions which, when the program is executed by the computer 202, cause the computer to carry out the method according to the embodiments.

[0080] A further exemplary embodiment relates to a data carrier signal DCS which transmits and / or characterizes the computer program PRG according to the embodiments. For example, the data carrier signal DCS can be received via an optional data interface 208 of the device 200.

[0081] In a further exemplary embodiment, the data interface 208 can also be configured to receive data from and / or transmit data onto the bus system 10, e.g. with the functionality of a bus transceiver 208a (e.g. a bus interface). Figure 5

[0082] In a further exemplary embodiment, the device 200 can have the functionality of a time-to-digital converter device 300, e.g. by means of an integrated hardware circuit 300' which can have, for example, the functionality of the time-to-digital converter device 300 described above with reference to Figure 2 In a further exemplary embodiment, at least one time-to-digital converter device 300, 300-1, 300-2 (e.g. a time-to-digital converter device 300-1) can also be integrated into the device 200 (i.e. e.g. on the same semiconductor substrate as the components 202, 204) or assigned to the device 200.

[0083] In a further exemplary embodiment, at least one time-to-digital converter device 300, 300-1, 300-2 (e.g. a time-to-digital converter device 300-1) can also be integrated into the device 200 (i.e. e.g. on the same semiconductor substrate as the components 202, 204) or assigned to the device 200. Figure 2 Figure 4

[0084] ​​​Further exemplary embodiments relate to the use of the method according to the exemplary embodiments and / or the device according to the exemplary embodiments and / or the computer-readable storage medium according to the exemplary embodiments and / or the computer program according to the exemplary embodiments and / or the data carrier signal according to the exemplary embodiments for at least one of the following elements: a) determining a position of a sender of the bus system, b) checking a position of a sender of the bus system, c) providing an intrusion detection system and / or an intrusion detection and prevention system, d) authenticating a sender of the bus system.

[0085] Figure 5 A simplified block diagram of a bus system 10' according to further exemplary embodiments is schematically shown. The bus system 10' is for example configured as a CAN bus system and has two bus lines 11a, 11b as transmission medium for differential transmission of a signal S. At the respective end of the bus 11a, 11b, in the present case exemplary termination resistors 12a, 12b are arranged, which terminate the bus lines 11a, 11b, for example to reduce reflections. Optional differential amplifiers 13a, 13b deliver extractable signals of the bus system 11 to time-to-digital converter devices 300 at measurement positions MP1, MP2, for example as respective input signals for a first (e.g. start) input 301 and a second (e.g. stop) input 302 of the time-to-digital converter devices 300, which measurement positions MP1, MP2 for example correspond to positions p1, p2 according to Figure 2 The time-to-digital converter devices 300 are configured to determine a first variable G1 and output it in digital form, for example via an interface 305, to a device 200', which for example has a configuration 200 according to Figure 4 or a similar configuration.

[0086] For example, the device 200' has a CAN bus transceiver 208a for receiving CAN messages from the bus system 10 and a data interface 208b for receiving the first variable G1 from the time-to-digital converter devices 300. In further exemplary embodiments, the components 208 according to Figure 4 have at least one of the interfaces 208a, 208b according to Figure 5

[0087] In further exemplary embodiments, for example a (CAN) transceiver can also be used instead of the optional differential amplifiers 13a, 13b, for example to generate a signal for the TDC.

[0088] Optionally, in further exemplary embodiments, the device 200' can output a result ERG, which can for example be determined based on the first variable G1, for example can be determined by an evaluation 120 according to further exemplary embodiments (not shown in the figure), for example a result ERG according to Figure 1 ​The information pS is determined by the interface 208. In another exemplary embodiment, the output of the result ERG can also be obtained via interface 208. Figure 4 )conduct.

[0089] Figure 7 A simplified block diagram of a bus system 10'' according to another exemplary embodiment is schematically shown. Line lengths l1, l2 are shown exemplary, and these line lengths can be obtained in a real implementation. In another exemplary embodiment, the corresponding input terminals 301, 302 of the time-to-digital converter device 300 ( Figure 2 The positions p1 and p2 of the connection ends are selected such that the line length l1 is less than the line length l2. Therefore, for example, a signal determined by the shorter line length l1 can provide a start signal, while a signal determined by the longer line length l2 can provide a stop signal.

[0090] Figure 8 A simplified block diagram of a bus system 10''' according to another exemplary embodiment is schematically shown, the bus system having a transmission medium different from... Figure 7 The topology or configuration.

[0091] Here, in another exemplary embodiment, the corresponding input terminals 301, 302 of the time-to-digital converter device 300 ( Figure 2 The positions p1 and p2 of the connection ends are also selected such that the line length l1 is less than the line length l2. Therefore, for example, a signal determined by the shorter line length l1 can provide a start signal, and a signal determined by the longer line length l2 can provide a stop signal.

[0092] Other exemplary implementations (see Figure 9 ) relates to the method and / or the device 200, 200' according to the embodiment and / or the computer-readable storage medium SM according to the embodiment and / or the computer program PRG according to the embodiment and / or the data carrier signal DCS according to the embodiment for the purpose 400 of at least one of the following elements: a) determining the position pS of the transmitter 5 of the bus system 10 (402) Figure 2 b) Check 404 ( Figure 9 c) The location pS of the transmitter 5 of the bus system 10 (e.g., by comparison with reference data RD or model M), d) Providing the 406 Intrusion Detection System and / or Intrusion Detection and Prevention System, and d) Verifying the 408 transmitter 5 of the bus system 10.

Claims

1. A computer-implemented method for determining information of a bus system (10) having a transmission medium (11) via which signals can be transmitted, the method comprising: determining (110) a first variable (Gl) characterizing a time difference (ZD) between a first point in time (tl) and a second point in time (t2), wherein at the first point in time (tl) a signal (S) output by a sender (5) onto the transmission medium (11) of the bus system (10) reaches a first location (pl) with respect to the transmission medium (11), wherein at the second point in time (t2) a signal output by the sender (5) onto the transmission medium (11) of the bus system (10) reaches a second location (p2) with respect to the transmission medium (11), evaluating (120) the first variable (Gl), wherein the first variable (Gl) is determined using at least two time-to-digital converter devices (300-1, 300-2), and outputting (140) a common start signal (S-start) to a first time-to-digital converter device (300-1) and a second time-to-digital converter device (300-2), at least temporarily connecting (142) a second input of the first time-to-digital converter device (300) with the transmission medium (11) at the first location (pl), at least temporarily connecting (144) a second input of the second time-to-digital converter device (300-2) with the transmission medium (11) at the second location (p2).

2. The method of claim 1, further comprising: at least temporarily connecting (130) a first input (301) of the time-to-digital converter device (300) with the transmission medium (11) at the first location (pl), at least temporarily connecting (132) a second input (302) of the time-to-digital converter device (300) with the transmission medium (11) at the second location (p2).

3. The method of any of the preceding claims, further comprising: determining (100) a model (M) and / or reference data (RD) of at least one sender which can be connected with the transmission medium (11) at a predefinable location, wherein the model (M) and / or the reference data (RD) characterize a first variable (Gl) of the at least one sender.

4. The method according to claim 3, wherein the evaluation (120) of the first variable (Gl) comprises: determining (120a) a location (pS) of the sender (5) based on the first variable (Gl), and / or comparing the first variable (Gl) with the model (M) or the reference data (RD).

5. The method of any of claims 1-2, further comprising: evaluating (122) information (I) characterized by the signal (S).

6. The method of claim 5, further comprising: determining (124) whether the sender (5) of the signal (S) is a device authorized to communicate via the bus system (10) based on the information (I) and the first variable (Gl).

7. The method according to claim 6, wherein when it has been determined that the sender (5) of the signal (S) is not a device authorized to communicate via the bus system (10), at least one countermeasure is initiated (126) which aims at preventing the transmission of the sender (5) and / or declaring the transmission invalid.

8. The method according to claim 1, wherein the method is used for at least one of the following elements: a) determining (402) a position (pS) of a sender (5) of the bus system (10), b) checking (404) a position (pS) of a sender (5) of the bus system (10), c) providing (406) an intrusion detection system and / or an intrusion detection and prevention system, d) verifying (408) a sender (5) of the bus system (10).

9. The method according to claim 1, wherein the second input is a stop input.

10. The method according to claim 1, wherein the first input (301) is a start input.

11. The method according to claim 1, wherein evaluating (122) information (I) represented by the signal (S) comprises extracting information from a message represented by the signal (S).

12. A device (200) for performing the method according to any one of claims 1 to 11.

13. A computer readable storage medium (SM) comprising instructions (PRG) which, when executed by a computer (202), cause the computer (202) to perform the method according to any one of claims 1 to 11.

14. A computer program product comprising instructions which, when executed by a computer (202), cause the computer to perform the method according to any one of claims 1 to 11.

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