Method for controlling and / or regulating a communication process

Abstract

The invention relates to a method for controlling and / or regulating a communication method for a bus, wherein the communication method enables acyclic communication with variable cycle lengths (Tz), in which applications (APP) and / or network participants (ecu) are offered successive transmission options (TO) for sending data units of different sizes, comprising: - Monitoring acyclic communication, - Determining, in particular measuring and / or calculating, a maximum cycle length (Tzmax) and / or a minimum cycle length (Tzmin) for acyclic communication, - Determining a desired base cycle length (Tb) for the applications (APP) and / or network participants (ecu), - Setting the desired base cycle length (Tb) for the applications (APP) and / or network participants (ecu), in particular to enable quasi-cyclic communication.

Description

[0001] The invention relates to a method for controlling and / or regulating a communication method, in particular a multi-drop communication method, for a bus, in particular a 10 Mbit / s Ethernet bus, for example in a vehicle. The communication method enables acyclic communication with variable cycle lengths, in which applications and / or network participants are offered successive transmission options for transmitting data units of different sizes. Furthermore, the invention relates to a corresponding computer program product, a corresponding control unit, and a corresponding vehicle for implementing a corresponding method.

[0002] The IEEE802.3cg standard (10 Mbit / s Ethernet) was introduced just a few years ago and is expected to soon find its way into the automotive world. It offers itself, for example, as a potential alternative to existing (partially) proprietary buses, such as A2B, as a more cost-effective replacement for 100 Mbit / s Ethernet, or as a competitor to the CAN / CAN-FD, CAN-XL, and FlexRay data bus. 10 Mbit / s (10SPE) was specified as an IEEE standard in the IEEE802.3cg working group and addresses, among other things, the area of ​​vehicle networking. A very special mode for automotive applications, called Multi-Drop (PLCA), is of interest. This is no longer a switched Ethernet, but a bus that does not require Ethernet switches. Bus access is ensured by a time-controlled round-robin procedure. The so-called headnode cyclically sends out a beacon and each node or network participant on the bus receives at least one transmission slot (so-calledIf this transmit opportunity (or TO for short) is not used, the next node or network participant gets a direct and faster turn (no bandwidth waste as with a TDMA-based data bus). These cycles are repeated continuously. This means that cycles can vary greatly in length. The 10 Mbit / s Ethernet bus is not a time-controlled bus, like the FlexRay bus, for example.

[0003] The technical challenge for cyclic communication in conjunction with the 10 Mbps Ethernet bus can be explained as follows: The technologically induced fluctuation in the cycle length of the 10 Mbps Ethernet bus can cause problems that can lead to the interruption of communication and customer-facing functions. Protocols such as SOME / IP and PTP (time synchronization) become inefficient when the transmission slots and / or the spacing between the transmission slots vary in length and are therefore unpredictable.

[0004] Cyclic communication can be enabled, for example, using the FlexRay bus. However, the FlexRay bus is comparatively expensive and often lacks the desired precision.

[0005] With the PLCA method, cyclic communication with fixed time slots is not possible per se. Due to the different transmission slot lengths, almost every cycle has a different length.

[0006] Known documents on the general state of the art are US 2022 / 0070021 A1 and DE 102020215086 A1.

[0007] It is therefore an object of the present invention to at least partially overcome at least one of the disadvantages described above. In particular, it is an object of the invention to provide a method for controlling and / or regulating a communication method, in particular a multi-drop communication method, for a bus, in particular a 10 Mbit / s Ethernet bus, which overcomes the technologically induced fluctuation in the cycle length of the 10 Mbit / s bus, which makes the transmission slots (or data unit lengths) and / or the distance between the transmission slots predictable, which provides quasi-cyclic communication, and which enables determinable transmission times for transmitting data units. Furthermore, it is an object of the present invention to provide a corresponding computer program product, a corresponding control unit, and a corresponding vehicle for carrying out a corresponding method.

[0008] The present invention provides a method for controlling and / or regulating a communication method, in particular a multi-drop communication method, for a bus, in particular a 10 Mbit / s Ethernet bus, having the features of independent method claim 1. Furthermore, the invention provides a corresponding computer program product, a corresponding control unit and a corresponding vehicle having the features of the corresponding independent claims 11, 12 and 14. Features and details that are described in connection with the different embodiments and / or aspects of the invention naturally also apply in connection with the other embodiments and / or aspects and vice versa, so that with regard to the disclosure of the individual embodiments and / or aspects, reference is or can always be made reciprocally.

[0009] The present invention provides: A method for controlling and / or regulating a communication method, in particular a multi-drop communication method, for a bus, in particular a 10 Mbit / s Ethernet bus, wherein the communication method enables acyclic communication with variable cycle lengths for applications and / or network participants (which can be referred to as nodes of the network that can access the bus), in which the applications and / or network participants are offered successive transmission options for transmitting data units (so-called frames) of different sizes.

[0010] The method comprising: - Monitoring acyclic communication, - Determining, in particular measuring and / or calculating, a maximum cycle length and / or a minimum cycle length for acyclic communication, - Determining a desired base cycle length for the applications and / or network participants, - Setting the desired base cycle length for the applications and / or network participants.

[0011] The method can be used in particular to enable quasi-cyclic communication.

[0012] Preferably, after setting the desired base cycle length for the applications and / or network participants, the method may comprise: - Offer the applications and / or network participants the basic cycle length with definable transmission times for sending data units.

[0013] Network participants can be understood as different control devices of different technical devices.

[0014] In a vehicle, there may be control units of different vehicle-specific systems, such as: - braking system, - steering system, - Driver assistance system, - navigation system, - communication system, - Infotainment system, - sensor system, - Heating and / or air conditioning system, etc.

[0015] In a vehicle, there may also be control units of various vehicle-specific devices, such as: - Sensor devices, e.g. temperature sensor, speed sensor, tire pressure sensor, distance sensor, impact sensor, etc., - GPS tracking device, - Safety devices, e.g. locking system, locking system, airbag, emergency call, etc., - Information devices, e.g. for weather forecasting, receiving traffic information, receiving news, etc. - Vehicle condition manager, - Time manager, - Comfort devices, e.g. door closing detectors, light-off detectors, parking position detectors, travel database, user calendar, information calls, etc.

[0016] Applications can be understood as different functions, e.g. safety-related, comfort-related, entertainment-related, etc., for example: - for parking, - for navigation, - for breakdown assistance, - for car sharing, - to form carpools, - for refueling / charging, - for tire pressure monitoring, - for shopping, etc.

[0017] Different applications can be deployed using different network participants.

[0018] The method provides a cost-effective, secure and fast solution for the upcoming vehicle generation(s) that will use a bus, in particular a 10 Mbit / s Ethernet bus, and / or that will rely on a multi-drop communication method.

[0019] The invention proposes that the bus and its configuration be monitored (preferably dynamically) by one, several, or even all network participants, and the minimum and maximum cycle lengths be determined. Advantageously, the number of active applications, the number of active network participants, the minimum and / or maximum permitted frame size at the network layer, the maximum permitted number of frames, and / or the configuration of the transmission options can be taken into account. Once the minimum and maximum cycle lengths are known, the desired base cycle length is determined. The base cycle length can then be set as the basis for the cycle. (Slower) cycle lengths can then be mapped to the base cycle length.

[0020] This method enables a cost-effective and reliable network system. It enables cyclic or time-controlled message transmission, despite the constantly fluctuating cycle length. It can increase bandwidth efficiency and ensure effective bandwidth utilization.

[0021] Using this method, a platform solution can be offered that can be dynamically adapted to a wide variety of variants (network system, number of services and service connections, and operating system resources).

[0022] Advantageously, the determination and setting of the base cycle length can be dynamically adjusted during runtime in order to react to node failures, partial network operation and functional extensions.

[0023] The method can ensure robust communication where the basic cycle length is the same and where nodes can schedule their transmission units.

[0024] The method therefore has significant advantages over the state of the art, as the method provides a dynamic and simple mechanism to maintain priorities / sequences with a simple Ethernet bus without violating latencies.

[0025] Consequently, a method for controlling and / or regulating a communication method, in particular a multi-drop communication method, for a bus, in particular a 10 Mbit / s Ethernet bus, can be provided, which overcomes the technologically induced fluctuation of the cycle length of the 10 Mbit / s bus, which makes the transmission slots (or data unit lengths) and / or the distance between the transmission slots predictable, which provides quasi-cyclic communication, and which enables determinable transmission times for transmitting data units.

[0026] The method can be implemented by at least one control unit of an application, by a network participant, and / or by a bus control unit. This allows for flexible implementation of the method. Advantageously, different nodes on the bus can assume a control and / or regulation role to enable quasi-cyclic communication.

[0027] Advantageously, the method can be repeated dynamically, in particular periodically and / or event-specifically, e.g., in the event of synchronization problems, and / or regularly, e.g., after a successful synchronization. In this way, the desired base cycle length can be adapted to changing conditions in a network.

[0028] In the method, it is conceivable that the method steps are carried out successively, at least partially overlapping and / or simultaneously.

[0029] Furthermore, in particular for setting the desired basic cycle length for the applications and / or network participants, at least one of the following method steps can be provided: - Detection of a synchronization time, in particular by receiving a start message or a transmission option, - Determining, in particular measuring and / or calculating, a previous or current cycle length, - Check whether data from applications and / or network participants is available for sending, - Determining a maximum allowed and / or possible data unit length, - Determining a maximum allowed number of data units, and / or - Determine an additional necessary data unit length so that the cycle length is in a desired grid.

[0030] This illustrates a partial section of the process used to set the desired base cycle length. After receiving a synchronization time, which can be a start message (so-called beacon) or a transmit opportunity (so-called transmit opportunity or TO for short), the previous cycle length can be calculated or measured. Based on the desired base cycle length / frequency, it is also possible to check whether data from applications and / or network participants is available for transmission. It is then possible to determine how small and how large the frames on the bus (so-called maximum transfer unit or MTU for short) may be, and how many frames a node may send for this transmission opportunity.

[0031] In this way, it can be determined how much data can be appended (generated additionally) to the potentially existing data so that the cycle is again in the desired grid.

[0032] Furthermore, at least one of the following method steps can be provided, in particular for determining, in particular measuring and / or calculating, a previous or current cycle length: - Checking time synchronization, - Measuring and / or calculating a previous or current cycle length depending on the checking,

[0033] For simplicity, if the time synchronization is sufficiently accurate, the previous cycle length can be calculated using an internal clock. If the time synchronization is not sufficiently accurate, the previous cycle length can be measured.

[0034] At this point, the step of determining the current cycle length can be presented in more detail. A distinction can be made between existing and sufficiently accurate time synchronization and no synchronization at all. If the bus and its nodes are already synchronized (e.g., through a protocol such as PTP, IEEE802.1AS, or IEEE1588), then under certain conditions, measuring the cycle length can be omitted or supplemented. If the time synchronization achieves a sufficiently high level of accuracy (with respect to the desired base cycle length) at the time of use, then it may be sufficient to determine the current cycle length using the internal clock upon receipt of a start message or a transmission opportunity and to calculate the adaptation of the next cycle. This sub-process can advantageously be repeated dynamically, e.g., in the event of synchronization problems and / or after synchronization has been achieved.

[0035] Furthermore, in particular for determining a desired basic cycle length for the applications and / or network participants, at least one of the following method steps can be provided: - Querying applications and / or network participants according to desired cycle, - Determining a desired base cycle length depending on the query, - Transmitting the desired base cycle length to the applications, network participants and / or bus control unit.

[0036] In the first substep, a node (network participant or control unit performing the cycle adjustment) can check which cycle lengths are theoretically possible. For this purpose, technical Ethernet parameters, bus participants, and / or any bus configurations, e.g., a burst mode, can be determined.

[0037] In the next step, with this knowledge, the bus nodes can be queried for a desired cycle (e.g., at startup). Optionally, the minimum cycle length can be communicated at this point. Based on feedback, the desired base cycle length can be determined, in particular calculated, which best matches the feedback, and this can be communicated to the bus participants. Due to the individual transmission capabilities of the individual nodes, each node can still have some leeway to influence or adjust the cycle. The desired cycle lengths can be queried, for example, by a higher protocol layer. The data can also be determined by reading in a configuration.

[0038] The desired base cycle length can be set once, for example, during end-of-line configuration, if the system is static and no changes will occur during runtime. The setting could then be read from the network configuration and statically preconfigured.

[0039] The desired base cycle length can advantageously be determined dynamically in order to be able to react to changes in the system.

[0040] In addition, in particular after determining a desired basic cycle length for the applications and / or network participants, at least one of the following method steps can be provided: - Determining a cycle repetition rate, in particular depending on the desired base cycle length and a maximum cycle length, e.g. as the desired base cycle length divided by the maximum cycle length, - Configuration of the cycle repetition rate depending on the determination.

[0041] Advantageously, if the cycle repetition rate is less than one, an error message can be generated, the desired base cycle length can be changed, the applications and / or network participants on the bus can be configured, etc. Furthermore, if the cycle repetition rate is greater than one, the method according to one of the preceding claims can be repeated. Furthermore, if the cycle repetition rate is equal to one, a positive feedback can be generated.

[0042] In this way, the cycle repetition rate can be calculated based on the desired base cycle length and the minimum / maximum bus cycle lengths. To avoid bandwidth waste and to still allow sufficient transmission opportunities within a cycle (less than a desired rate), the frequency can be the smallest possible divisor of the desired base cycle.

[0043] In addition, at least one of the following method steps can be provided, in particular for setting the desired basic cycle length for the applications and / or network participants: - Analyzing network hardware, - Analyzing a jumbo data unit support and / or a jumbo data unit length, - Analyzing a burst mode configuration, - Analyzing a padding support and / or a padding length, and / or - Selecting and / or applying measures to set the desired base cycle length depending on the analysis.

[0044] Theoretically, several options are available for adjusting the cycle length on 10 Mbit Ethernet. A network analysis can be performed for this purpose. Support for jumbo frames can be checked. Furthermore, the maximum frame length can be determined. A burst mode configuration and / or padding support can then be tested.

[0045] Based on the desired cycle length, it can be checked which method can achieve which cycle length.

[0046] Jumbo frames, if supported, cannot be of arbitrary length. For example, a cycle with 9000 bytes, which is six times longer than the typical frame length of 1500, can be set to approximately 7.2 ms instead of 1.2 ms.

[0047] With padding support, advantageously supported by any hardware, an existing frame that is too small can typically be expanded / stuffed to 64 bytes.

[0048] With burst mode, 255*1500 bytes are possible.

[0049] Advantageously, when setting the desired basic cycle length for the applications and / or network participants, a number of active applications and / or network participants can be taken into account in the acyclic communication.

[0050] Preferably, in particular for setting the desired basic cycle length for the applications and / or network participants, at least one of the following method steps can be provided: - Monitoring a network management status, - Determine passive and / or sleeping applications and / or network participants at a specific time, - Determine active applications and / or network participants at a specific time, - Determining a maximum cycle length and / or a minimum cycle length at a specific time, - Determine necessary changes to set the desired base cycle length.

[0051] Partial network operation of control units / nodes plays an increasingly important role in vehicles, saving energy and thus, for example, increasing the range of electric cars. Control units can either planned or unplannedly leave the bus. This changes the bus cycle length, as the transmission options (TOs) are either used or not used. It is also possible that several or almost all participants remain away from the bus or only participate in communication at a specific time.

[0052] The determination of active and passive nodes on the bus can be done, for example, through higher-level protocols such as network management protocols or through physical measurements on the actual cable. If this information is available, it plays a role in adapting or setting the base cycle, as different methods may need to be used or the base cycle may need to be adjusted.

[0053] Furthermore, the method may comprise at least one of the following method steps: - Check whether there are any transmission units that should be sent at specific times, e.g. for a clock synchronization, an error memory dump, etc., and / or when and / or with what accuracy the transmission units should be sent, - Determining, in particular predictively determining, a cycle in which the transmission units can probably be sent, - Determining a variance for a transmission time of the cycle at which the transmission units can probably be sent, - Determining a start time for a cycle adjustment to achieve a transmission time with a desired variance, - Adjusting the desired base cycle length depending on the determination, preferably at the specific start time for the cycle adjustment.

[0054] This allows for a single or multiple cycle adjustment, allowing for a single or multiple time points to be set. This allows for the bus to be controlled without the need for constant operation, thus conserving system resources.

[0055] For example, there are events that only occur at specific times, such as a clock synchronization or an error memory dump, etc. These events can occur at specific times and be pre-assigned with a certain tolerance. This sub-procedure can check the future time together with the previous or current bus characteristics and determine a transmission time. If the accuracy (bus fluctuation) is not sufficient, the procedure can determine the start time for adjusting the cycle and then execute it. This can be done very slowly and with minimal changes, e.g. relatively quickly or with a lead time in order to set a suitable base cycle in good time at relevant times. The selection can either be determined by the system or adjusted based on the current communication.

[0056] The invention further provides: a corresponding computer program product, comprising instructions that, when executed by a computer, cause the computer to perform the method, which can proceed as described above. The computer program product can achieve the same advantages as those described above in connection with the method according to the invention. These advantages are incorporated herein by reference.

[0057] A corresponding control unit provides a further aspect of the invention. A computer program in the form of code can be stored in a memory unit of the control unit. When the code is executed by a computing unit of the control unit, the program performs a method that can proceed as described above. The control unit can achieve the same advantages as those described above in connection with the method according to the invention. These advantages are incorporated herein by reference in their entirety.

[0058] The control unit can be implemented at least partially in at least one control unit of an application, in at least one network participant, which itself can be designed as a control device and form a node of the network, and / or at least partially in a bus control unit.

[0059] A corresponding vehicle with a corresponding control unit provides a further aspect of the invention. Using the charging system, the same advantages described above in connection with the method according to the invention can be achieved. These advantages are incorporated herein by reference.

[0060] Further advantages, features, and details of the invention will become apparent from the following description, which describes exemplary embodiments of the invention in detail with reference to the drawings. The features mentioned in the claims and in the description may be advantageous individually or in any combination. They show: Fig. 1 an exemplary communication procedure with acyclic communication, and Fig. 2 an exemplary sequence of a method for controlling and / or regulating the communication process, and Fig. 3 to 6- exemplary aspects of the procedure.

[0061] The Fig. Figure 1 illustrates the IEEE802.3cg (10 Mbit / s Ethernet) standard, which can represent an alternative to existing (partially) proprietary buses, such as A2B, as a more cost-effective replacement for 100 Mbit / s Ethernet, or as a competitor to the CAN / CAN-FD, CAN-XL, and FlexRay data buses. 10 Mbit / s (10SPE) was specified as an IEEE standard in the IEEE802.3cg working group and addresses, among other things, the area of ​​vehicle networking.

[0062] For vehicles, a special communication method called Multi-Drop (PLCA) is of interest. This is a bus that does not require Ethernet switches. Bus access is ensured by a time-controlled round-robin procedure, as is the case with Fig. 1. A main node, the so-called headnode, can cyclically send a start message B, the so-called beacon, and each node on the bus is allocated at least one transmit slot or one transmit opportunity TO (English for "transmit opportunity"). If this transmit slot is not used, the next node or network participant gets the next transmission directly and more quickly (no bandwidth waste as with a TDMA-based data bus). These cycles are repeated continuously. This allows cycles to vary greatly in length, as shown in the example in the Fig. 1. The Mbit / s Ethernet bus is therefore not a time-controlled bus, such as the FlexRay bus.

[0063] The minimum cycle length Tzmin can be calculated as follows: Tzmin = 20 bits (minimum size of a data unit) * number of connected nodes.

[0064] Using the example of 8 nodes, this is 2 µs. Minimal means that no node detects a TO transmission opportunity.

[0065] A (typical) maximum cycle length Tzmax is just under 10 ms with a full frame length of 1500 bytes (maximum size of a data unit) and an exemplary number of nodes of 8.

[0066] To achieve higher throughput, burst mode can be used, which allows nodes to send up to 255 frames or data units per transmission opportunity. This can have a significant impact on the maximum cycle length and latency on the "slow" 10 Mbps Ethernet bus.

[0067] The minimum cycle length Tzmin remains the same, but the maximum cycle length Tzmax can theoretically increase to 1500 bytes (maximum size of a data unit) * 255 * 8, which can mean about 2.5 s for 8 nodes.

[0068] The technical challenge lies in the fluctuation of the cycle length Tz of the 10 Mbps Ethernet bus, which can lead to the interruption of communication and customer-facing functions. Protocols such as SOME / IP and PTP (time synchronization) become inefficient when the transmission slots and / or the interval between them vary in length and are therefore unpredictable.

[0069] With the PLCA method, cyclic communication with fixed time slots is not possible per se. Due to the different transmission slot lengths, almost every cycle has a different length.

[0070] To at least partially overcome the disadvantages described above, the invention provides a method for controlling and / or regulating a communication method, in particular a multi-drop communication method (PLCA), for a bus, in particular a 10 Mbit / s Ethernet bus, having the features of the independent method claim. Furthermore, the invention provides a corresponding computer program product, a corresponding control unit (ECU), and a corresponding vehicle (not shown for reasons of simplicity).

[0071] The communication method enables acyclic communication with variable cycle lengths Tz for applications APP and / or network participants ecu (which can be referred to as nodes of the network that can access the bus), in which the applications APP and / or network participants ecu are offered successive transmission options TO for sending data units so-called frames of different sizes.

[0072] As the Fig. 2 schematically shows the method comprises the following steps: 110 Monitoring acyclic communication, 120 Determining, in particular measuring and / or calculating, a maximum cycle length Tzmax and / or a minimum cycle length Tzmin in acyclic communication, 130 Determining a desired base cycle length Tb for the applications APP and / or network participants ecu, 110 Setting the desired base cycle length Tb for the applications APP and / or network participant ecu.

[0073] In this way, quasi-cyclic communication can be enabled.

[0074] Preferably, after setting the desired basic cycle length Tb for the applications APP and / or network participants ecu, the method may comprise at least one of the following method steps: 150 Offer the applications APP and / or network participants ecu the basic cycle length Tb with determinable transmission times for sending data units.

[0075] Different control units of different technical devices can serve as network participants (ecu) or nodes of the network.

[0076] In a vehicle, there may be control units of different vehicle-specific systems, such as: - braking system, - steering system, - Driver assistance system, - navigation system, - communication system, - Infotainment system, - sensor system, - Heating and / or air conditioning system, etc.

[0077] In a vehicle, there may also be control units of various vehicle-specific devices, such as: - Sensor devices, e.g. temperature sensor, speed sensor, tire pressure sensor, distance sensor, impact sensor, etc., - GPS tracking device, - Safety devices, e.g. locking system, airbag, emergency call, etc., - Information devices, e.g. for weather forecasting, receiving traffic information, receiving news, etc. - Vehicle condition manager, - Time manager, - Comfort devices, e.g. door closing detectors, light-off detectors, parking position detectors, travel database, user calendar, information calls, etc.

[0078] APP applications can be understood as different functions, e.g. safety-related, comfort-related, entertainment-related, etc., for example: - for parking, - for navigation, - for breakdown assistance, - for car sharing, - to form carpools, - for refueling / charging, - for tire pressure monitoring, - for shopping, etc.

[0079] Certain applications APP can be provided using different control units or network participants ecu.

[0080] The method provides a cost-effective, secure and fast solution for future vehicle generations that use a bus, in particular a 10 Mbit / s Ethernet bus, and / or that will rely on a multi-drop communication method PLCA.

[0081] The invention proposes that the bus and its configuration be monitored (preferably dynamically) by one, several, or even all network participants (ecu), and the minimum and maximum cycle lengths (Tzmin and Tzmax) be determined. Advantageously, the number of active applications (APP), the number of active network participants (ecu), the minimum and / or maximum permitted frame size at the network layer, the maximum permitted number of frames, and / or the configuration of the transmission options can be taken into account.

[0082] Once the minimum and maximum cycle lengths Tzmin and Tzmax are known, the desired base cycle length Tb is determined. The base cycle length Tb can then be set as the basis for the cycle on the bus. Other cycle lengths (slower cycle lengths, longer cycle lengths, or a slower frequency) can then be mapped to the base cycle length.

[0083] The method enables a cost-effective and at the same time reliable control and / or regulation of a communication method, in particular a multi-drop communication method PLCA, for a bus, in particular a 10 Mbit / s Ethernet bus.

[0084] This method enables quasi-cyclic or time-controlled message transmission, despite the constantly fluctuating cycle length. This method can increase bandwidth efficiency and thus enable effective use of the bus.

[0085] Using this method, a platform solution can be offered that can be dynamically adapted to a wide variety of network system variants, the number of services, service connections and operating system resources.

[0086] Advantageously, the determination and setting of the cycle length can be carried out dynamically during runtime in order to react to node failures, partial network operation or functional extensions.

[0087] The method can ensure robustness of communication by choosing the base cycle length Tb at which the nodes can schedule their transmission units.

[0088] The method has significant advantages over the state of the art because it provides a dynamic and simple mechanism to ensure that priorities / sequences can be maintained on a simple Ethernet bus without violating latencies.

[0089] Consequently, a method for controlling and / or regulating a communication method, in particular a multi-drop communication method PLCA, for a bus, in particular a 10 Mbit / s Ethernet bus, can be provided, which overcomes the technologically induced fluctuation of the cycle length of the 10 Mbit / s bus, which makes the transmission slots (or data unit lengths) and / or the distance between the transmission slots predictable, which provides a quasi-cyclic communication, and which enables determinable transmission times for transmitting data units.

[0090] The method can be provided as a software-implemented solution and can be performed by at least one control unit of an application APP, by a network participant ecu and / or by a bus control unit.

[0091] In the method, it is conceivable that the method steps can be carried out successively, at least partially overlapping and / or simultaneously.

[0092] The Fig. Figure 3 shows a second partial aspect of the method (sub-method 2), in particular for setting the desired basic cycle length Tb for the applications APP and / or network participants ecu: 210 Detection of a synchronization time, in particular by receiving a start message B or a transmission option TO, 220 Determining, in particular measuring and / or calculating, a previous or current cycle length Tzi, 230 Check whether data D from applications APP and / or network participants ecu is available for sending, 240 Determining a maximum allowed and / or possible data unit length, 250 Determining a maximum allowed number of data units, and / or 260 Determining an additional necessary data unit length so that the cycle length Tz is in a desired grid.

[0093] Sub-procedure 2 shows a partial section of the procedure used to set the desired base cycle length Tb. After receiving a synchronization time, which can be a start message B (so-called beacon) or a transmit opportunity TO (so-called transmit opportunity or TO for short), the previous cycle length Tzi can be calculated or measured. Based on the desired base cycle length / frequency, it can also be checked whether data from applications and / or network participants is available for transmission. It can then be determined how small and how large the frames on the bus (so-called maximum transfer unit or MTU for short) can be and how many frames can be sent from this node for this transmit opportunity TO.

[0094] In this way, it can be determined how much data D can still be appended (generated additionally) to the potentially already existing data D so that the cycle is again in the desired grid.

[0095] The Fig. 4 shows a third partial aspect of the method (sub-method 3), in particular for determining, in particular measuring and / or calculating, a previous or current cycle length Tzi: 310 Checking a time synchronization, - Measuring 330 and / or calculating 320 a previous or current cycle length Tzi depending on the checking,

[0096] As the Fig. As suggested in Figure 4, the previous cycle length Tzi can be calculated using an internal clock if the time synchronization is sufficiently accurate.

[0097] If the time synchronization does not have sufficient accuracy, the previous cycle length Tzi can be measured.

[0098] In sub-procedure 3, the step of determining the current cycle length Tzi can be presented in more detail. In this case, a distinction can be made between existing and sufficiently accurate time synchronization and no synchronization. If the bus and its nodes are already synchronized, e.g., using a protocol such as PTP, IEEE802.1AS, or IEEE1588, then under certain conditions measurement 300 of the cycle length Tzi can be omitted or supplemented. If the time synchronization has achieved a sufficiently high level of accuracy with regard to the desired base cycle length at the time of use, then it may be sufficient to determine the current cycle length Tzi using the internal clock upon receipt of a start message B or a transmission option TO and to calculate the adaptation of the next cycle. This sub-procedure 3 can advantageously be repeated dynamically, e.g.in case of synchronization problems and / or after synchronization has been achieved.

[0099] The Fig. Figure 5 shows a fourth aspect of the method (sub-method 4), in particular for determining a desired base cycle length Tb for the applications APP and / or network participants ecu: 410 queries from applications APP and / or network participants ecu according to desired cycle, 420 Determining a desired base cycle length Tb depending on the query, 430 Transmitting the desired base cycle length Tb to the applications APP, network participant ecu and / or bus control unit.

[0100] In sub-process 4, in the first sub-step, a node or network participant performing the cycle adjustment can check which minimum and / or maximum cycle lengths Tzmin, Tzmax are possible. For this purpose, technical Ethernet parameters, bus participants, and / or any bus configurations, e.g., a burst mode, can be checked.

[0101] In the next substep, with this knowledge, the bus nodes can be queried for a desired cycle (e.g., at startup). Optionally, the minimum cycle length can be communicated at this point. Based on feedback, the desired base cycle length Tb can be determined, or in particular calculated, which best matches the feedback, and this can be communicated to the bus participants. Due to the individual transmission capabilities of the individual nodes, each node can still have some leeway to influence or adjust the cycle. The query for desired cycle lengths can, for example, be performed by a higher protocol layer. The data can also be determined by reading in a configuration.

[0102] The desired base cycle length Tb can be set once, for example, during end-of-line configuration, if the system is static and no changes will occur during runtime. The setting could then be read from the network configuration and statically preconfigured.

[0103] The desired base cycle length can advantageously be determined dynamically in order to be able to react to changes in the dynamically changing system.

[0104] The Fig. Figure 6 shows a fifth aspect of the method (sub-method 5), in particular after determining a desired base cycle length Tb for the applications APP and / or network participants ecu: 510 Determining a cycle repetition rate zwd, in particular depending on the desired base cycle length Tb and a maximum cycle length Tzmax, e.g. as the desired base cycle length Tb divided by the maximum cycle length Tzmax, 520 Configuration of the cycle repetition rate zwd depending on the determination.

[0105] The Fig. 6 indicates in step 530 that if the cycle repetition rate zwd is less than one, then configuration is not possible without significant changes. In this case, an error message can be generated, the desired base cycle length Tb can be changed, the applications APP and / or network participants ecu on the bus can be reconfigured, etc.

[0106] The Fig. 6 indicates in step 540 that if the cycle repetition rate is greater than one, the method according to Fig. 1 can be repeated.

[0107] Advantageously, positive feedback can be generated when the cycle repetition rate is equal to one. In this case, the desired base cycle length Tb is optimally set.

[0108] In sub-method 5, the cycle repetition rate zwd can be calculated based on the desired base cycle length Tb and the minimum and / or maximum cycle lengths Tzmin, Tzmax. To avoid bandwidth waste and to continue to allow sufficient transmission options even within a cycle (less than a desired rate), the frequency can be the smallest possible divisor of the desired base cycle length Tb.

[0109] A sixth aspect of the method (sub-method 6) can be provided (the method steps are numbered for better understanding), in particular for setting the desired base cycle length Tb for the applications APP and / or network participants ecu: 610 Analyzing network hardware, 620 Analyzing a jumbo data unit support and / or a jumbo data unit length, 630 Analyzing a Burst Mode Configuration, 640 Analyzing a padding support and / or a padding length, and / or 650 Selecting and / or applying measures to set the desired base cycle length Tb depending on the analysis.

[0110] Sub-method 6 demonstrates several options available on the 10 Mbps Ethernet bus for adjusting the cycle length Tz. A network analysis can be performed for this purpose. Furthermore, support for jumbo frames can be checked. Furthermore, the maximum frame length can be determined. A burst mode configuration and / or padding support can be tested subsequently.

[0111] Based on the desired cycle length, it can be checked which method can achieve which cycle length.

[0112] Jumbo frames, if supported, cannot be of arbitrary length. For example, a cycle with 9000 bytes, which is six times longer than the typical frame length of 1500, can be set to approximately 7.2 ms instead of 1.2 ms.

[0113] With padding support, advantageously supported by any hardware, an existing frame that is too small can typically be expanded / stuffed to 64 bytes.

[0114] With burst mode, 255*1500 bytes are possible.

[0115] Advantageously, when setting the desired basic cycle length Tb for the applications APP and / or network participants ecu, a number of active applications APP and / or network participants ecu can be taken into account in the acyclic communication.

[0116] A seventh aspect of the method (sub-method 7) can be provided (the method steps are numbered for better understanding), in particular for setting the desired base cycle length Tb for the applications APP and / or network participants ecu: 710 Monitoring a network management status, 720 Determining passive and / or sleeping applications APP and / or network participants ecu at a specific time, 730 Determining active applications APP and / or network participants ecu at a specific time, 740 Determining a maximum cycle length Tzmax and / or a minimum cycle length Tzmin at a specific time, 750 Determine necessary changes to set the desired base cycle length Tb.

[0117] Sub-method 7 recognizes that sub-network operation of control units / nodes is playing an increasingly important role in vehicles, saving energy and thus, for example, increasing the range of electric cars. Control units can either planned or unplannedly stay away from the bus. This changes the bus cycle length Tz, as the transmission options TO are either used or not used. It is also possible that several or almost all participants stay away from the bus or only participate in communication at a certain point in time. Method 7 can advantageously take this into account to adapt the cycle accordingly.

[0118] The determination of active and passive nodes on the bus can be done, for example, through higher-level protocols such as network management protocols or through physical measurements on the actual cable. If information about this is available, it can play a role in adjusting the corresponding settings for the base cycle length Tb, as other methods may be used here or the base cycle may also need to be adjusted.

[0119] An eighth aspect of the procedure (sub-procedure 8) may be provided (the procedural steps are numbered for better understanding): 810 Check whether there are any transmission units that should be sent at specific times, e.g. for a clock synchronization, an error memory dump, etc., and / or when and / or with what accuracy the transmission units should be sent, 820 Determining, in particular predictively determining, a cycle in which the transmission units can probably be sent, 830 Determining a variance for a transmission time in the cycle at which the transmission units can probably be sent, 840 Determining a start time for a cycle adjustment to meet a transmission time with a desired variance, 850 Adjusting the desired base cycle length Tb depending on the determination, preferably at the specific start time for the cycle adjustment.

[0120] Subprocess 8 can provide a single or multiple cycle adjustment, allowing for only one or multiple time points to be set. This allows for the bus to be controlled without having to be continuously monitored, thus conserving system resources.

[0121] For example, there are events that only occur at specific times, such as a clock synchronization or an error memory dump, etc. These events can occur at specific times and be pre-assigned with a certain tolerance. Sub-procedure 8 can check the future time together with the previous bus characteristics and determine a transmission time. If the bus's accuracy is insufficient, the procedure can determine the start time for adjusting the cycle and then execute it. This can be done very slowly and with minimal changes, e.g., relatively quickly or with a lead time in order to set a suitable base cycle in good time at relevant times. The selection can either be determined by the system or adjusted based on the current communication.

[0122] A corresponding computer program product, a corresponding control unit ECU with a memory unit MU and a computing unit CU and a corresponding vehicle with a corresponding control unit ECU also represent aspects of the invention.

[0123] The control unit ECU can be implemented at least partially in at least one control unit of an application APP, in at least one network participant (ecu) and / or at least partially in a bus control unit.

[0124] The above explanation of the embodiments describes the present invention exclusively within the scope of examples. Of course, individual features of the embodiments can be freely combined with one another, provided they are technically feasible, without departing from the scope of the present invention. List of reference symbols APP application B Start message D Data ecu network participants CU computing unit ECU control unit MU storage unit TO broadcasting options / broadcast slots Tz cycle length Tzi cycle length Tzmax maximum cycle length Tzmin minimum cycle length Tb basic cycle length zwd cycle repetition rate

Claims

[1] Method for controlling and / or regulating a communication method for a bus, wherein the communication method enables acyclic communication with variable cycle lengths (Tz), in which applications (APP) and / or network participants are offered the following transmission options (TO) for transmitting data units of different sizes, comprising: - Monitoring acyclic communication, - Determining a maximum cycle length (Tzmax) and / or a minimum cycle length (Tzmin) for acyclic communication, - Determining a desired base cycle length (Tb) for the applications (APP) and / or network participants (ecu), - Setting the desired base cycle length (Tb) for the applications (APP) and / or network participants (ecu). [2] Method according to claim 1, wherein, when determining a maximum cycle length (Tzmax) and / or a minimum cycle length (Tzmin), a number of active applications (APP) and / or network participants (ecu) in the acyclic communication, a maximum and / or minimum permitted data unit length, a maximum permitted number of data units and / or a configuration of a transmission option are / will be taken into account, and / or wherein the method is carried out by at least one control unit of an application (APP), by a network participant (ecu) and / or by a bus control unit. [3] Method according to one of the preceding claims, where the process is repeated dynamically, and / or wherein the method steps are carried out successively, at least partially overlapping and / or simultaneously. [4] Method according to one of the preceding claims, further comprising: - Detecting a synchronization point, - Determination of a previous cycle length (Tzi), - Check whether data (D) from applications (APP) and / or network participants (ecu) is available for sending, - Determining a maximum allowed and / or possible data unit length, - Determining a maximum allowed number of data units, and / or - Determine an additional necessary data unit length so that the cycle length (Tz) is in a desired grid. [5] Method according to one of the preceding claims, further comprising: - Checking time synchronization, - Measuring and / or calculating a previous cycle length (Tzi) depending on the check. [6] Method according to one of the preceding claims, further comprising: - Querying applications (APP) and / or network participants (ecu) according to desired cycle, - Determining a desired base cycle length (Tb) depending on the query, - Transmitting the desired base cycle length (Tb) to the applications (APP), network participants (ecu) and / or bus control unit. [7] Method according to one of the preceding claims, further comprising: - Determining a cycle repetition rate (zwd), - Configuration of the cycle repetition rate (zwd) depending on the determination. [8] Method according to one of the preceding claims, further comprising: - Analyzing network hardware, - Analyzing a jumbo data unit support and / or a jumbo data unit length, - Analyzing a burst mode configuration, - Analyzing a padding support and / or a padding length, and / or - Selecting and / or applying measures to set the desired base cycle length (Tb) depending on the analysis. [9] Method according to one of the preceding claims, wherein when setting the desired basic cycle length (Tb) for the applications (APP) and / or network participants (ecu), a number of active applications (APP) and / or network participants (ecu) are taken into account in the acyclic communication, and / or the method further comprising: - Monitoring a network management status, - Determine passive and / or sleeping applications (APP) and / or network participants (ecu) at a specific time, - Determine active applications (APP) and / or network participants (ecu) at a specific time, - Determination of a maximum cycle length (Tzmax) and / or a minimum cycle length (Tzmin) at a specific time, - Determine necessary changes to set the desired base cycle length (Tb). [10] Method according to one of the preceding claims, further comprising: - Check whether there are any transmission units that should be sent at specific times and / or when and / or with what accuracy the transmission units should be sent, - Determining a cycle in which the transmit units can probably be sent, - Determining a variance for a transmission time of the cycle at which the transmission units can probably be sent, - Determining a start time for a cycle adjustment to achieve a transmission time with a desired variance, - Adjusting the desired base cycle length (Tb) depending on the determination, preferably at the specific start time for the cycle adjustment. [11] Computer program product comprising instructions which, when the computer program product is executed by a computer, cause the computer to carry out the method according to one of the preceding method claims 1 to 10. [12] Control unit (ECU), comprising a computing unit (CU) and a memory unit (MU) in which instructions are stored which, when at least partially executed by the computing unit (CU), carry out a method according to one of the preceding method claims 1 to 10. [13] Control unit (ECU) according to claim 12, wherein the control unit (ECU) is implemented at least partly in at least one control unit of an application (APP), in at least one network participant (ecu) and / or at least partly in a bus control unit. [14] Vehicle comprising a control unit (ECU) according to one of the preceding claims 12 or 13.

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