Method for initializing a bus node in a communication bus system, bus node, monitoring bus node, and communication bus system
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- CONTINENTAL AUTOMOTIVE TECHNOLOGIES GMBH
- Filing Date
- 2026-01-20
- Publication Date
- 2026-08-06
Smart Images
Figure EP2026051249_06082026_PF_FP_ABST
Abstract
Description
[0001] 2020404697
[0002] 1
[0003] Description
[0004] Method for initializing a bus node of a communication bus system, bus node, monitoring bus node and a communication bus system
[0005] The invention relates to a method for initializing a bus node of a communication bus system, a bus node of a communication bus system, a monitoring bus node of a communication bus system, and a communication bus system.
[0006] Certain communication bus systems require that bus messages sent via a communication bus of the system be assigned a unique bus message identification value. This bus message identification value may only be used by a single node of the communication bus system to send the bus message. If the bus message identification value is used by more than one node, the operation of the communication bus system will malfunction. Such a communication bus system can be, for example, a CAN bus (Controller Area Network) or a LIN bus (Local Interconnect Network). In the context of the CAN bus, the bus message identification value is referred to as the ID (Identifier).
[0007] The selection of bus message identification values is generally based on the data type to be transmitted in the bus message and the device type of the bus node. In communication bus systems where a device type occurs only once, the bus message identification values are therefore used by only one of the bus nodes. If a device type occurs at least twice in the communication bus system, the bus message identification values can be used twice, leading to a collision. The use of multiple bus nodes of the same device type is particularly common in sensor systems for environmental perception.
[0008] 2
[0009] To avoid this collision, it is common practice in such communication bus systems to derive the bus message identification values not from the device identifier, which depends on the device type, but from a different identifier that is unique to the bus node.
[0010] German patent DE 102018205082 B4 describes a method in which identical slave modules are initially installed in a vehicle without configuration and only programmed after installation. This allows a common logistics part number to be assigned to each slave module.
[0011] DE 102021 203874 A1 describes a determination of an identifier based on recorded sensor data.
[0012] It is therefore an object of the invention to ensure communication via a communication bus system when using identical bus nodes.
[0013] A first aspect of the invention relates to a method for initializing a bus node of a communication bus system. The bus node can, for example, include a transceiver that may be configured for a tracking system to locate a key fob in the vicinity of a vehicle. Several bus nodes, each with identical transceivers, can be connected to the communication bus system.
[0014] It is provided that a non-volatile bus node identification value is stored in a memory unit of the bus node. This bus node identification value can be determined by a sensor unit of the bus node and may depend on the installation position of the bus node in a vehicle. For example, the bus node identification value may depend on the states described in DE 102021 203874 A1. The bus node identification value may also have been stored in the memory unit during the manufacturing of the bus node. The non-volatile 2020404697
[0015] 3
[0016] The bus node identification value may have been used by the bus node during a previous communication session.
[0017] In the first step of the procedure, the non-volatile bus node identification value stored in the memory unit of the bus node is read out by the bus node.
[0018] The non-volatile bus node identification value can have a validity state. This validity state can depend on the value of the bus node identification value. For example, a predefined total value range of the bus node identification value can be divided into predefined value ranges, where each value range can be assigned to one of the validity states. The predefined value ranges and the validity states assigned to them can be stored in the bus node, allowing the bus node to assign the bus node identification value to the corresponding value range and consequently determine its validity state.
[0019] In a second process step, the validity state of the bus node's non-volatile bus node identification value is determined. For example, the validity state could indicate that the bus node identification value is "Brand New." This state could mean that the bus node is newly connected to the communication bus system and has not yet participated in any session. In this case, the validity state "Brand New" could, for example, indicate that the non-volatile bus node identification value does not contain any information about the bus node's installation position. Therefore, it may be necessary to determine the bus node's installation position. For example, the validity state could indicate that the bus node identification value is "Valid."The validity state “valid” can describe that the non-volatile bus node identification value was used in a previous session as the active bus node identification value to identify the bus node, with the session finding that the active 2020404697.
[0020] 4
[0021] The bus node identification value is "valid". The bus node identification value can be rated as "valid" if it correctly describes the installation position of the bus node in the session.
[0022] For example, the validity state can describe that the bus node identification value is "invalid". The "invalid" validity state can describe that the non-volatile bus node identification value was used as the active bus node identification value to identify the bus node in the previous session, but the session then determined that the active bus node identification value was "invalid". The bus node identification value can be evaluated as "invalid" if it does not correctly describe the installation position of the bus node in the session.
[0023] In a further step, the active bus node identification value is to be determined for the individual identification of the bus node in a session via a communication bus of the communication bus system according to a predefined bus node identification value determination procedure. In other words, the active bus node identification value is to be determined, which is used by the bus node to identify itself via the communication bus during the session. Use of the active bus node identification value in the session can include using it as a basis or characteristic for generating bus message identification values, which are used by the bus node to send bus messages to the communication bus in the session.The active bus node identification value can also be used in the session as a basis or characteristic for generating the bus message identification values, which identify the bus messages to be received by the bus node in the session via the communication bus. A specification for generating the bus message identification values depending on the active bus node identification value can be stored in the bus node. 2020404697.
[0024] 5
[0025] It is intended that the determination of the active bus node identification value according to the bus node identification value determination procedure depends on the validity state determined for the non-volatile bus node identification value of the bus node. In other words, the bus node identification value determination procedure performed by the bus node to determine the active bus node identification value depends on the validity state of the non-volatile bus node identification value. It may be provided that each of the validity states is assigned a corresponding execution of the bus node identification value determination procedure. This makes it possible to make the determination of the active bus node identification value dependent on whether the non-volatile bus node identification value of the bus node has the validity state "factory new," "valid," or "invalid."For example, it may be provided that in the case of a validity state of "brand new" and a validity state of "invalid" of the non-volatile bus node identification value, the bus node identification value determination procedure is carried out, which includes an identification of a current installation position of the bus node.
[0026] It is intended that a communication state of the bus node for communication via the communication bus is activated using the active bus node identification value. The communication state can, for example, be set to online. This allows the bus node to participate in a communication session according to the CAN bus standard.
[0027] A further development of the invention provides that, in a first validity state of the non-volatile bus node identification value, a volatile bus node identification value of the bus node is determined according to a predetermined bus node identification procedure. In other words, it is provided that if the non-volatile bus node identification value is in the first validity state, the volatile bus node identification value is determined according to a predetermined bus node identification procedure.
[0028] 6
[0029] The bus node identification value is determined by the bus node according to the bus node identification procedure. For example, the first validity state can describe the "factory-new" validity state of the non-volatile bus node identification value of the bus node. The non-volatile bus node identification value may have been stored in the memory unit during the production of the bus node.
[0030] The bus node identification procedure can, for example, include reading a value from a sensor unit located at the bus node. The bus node identification procedure can also include a step of sensing the sensor's environment and determining the bus node identification value based on this environment. In a further step of the bus node identification value determination procedure, the volatile bus node identification value is set as the active bus node identification value. In other words, the volatile bus node identification value determined by the bus node is set as the active bus node identification value used to identify the bus node in the bus communication system.Using the first validity state, which denotes the "brand new" state, has the advantage that bus nodes for which the bus node identification procedure needs to be carried out can be identified.
[0031] A further development of the invention provides that, in the first validity state of the non-volatile bus node identification value, the bus node sends an identification bus message, comprising the volatile bus node identification value of the bus node, via the communication bus in the specified bus node identification value determination procedure. In other words, it is provided that the bus node informs the bus communication system of the volatile bus node identification value via the identification bus message to the communication bus, which is then used by the bus node as the active bus node identification value.
[0032] 7
[0033] In a further step of the bus node identification value (BND) determination process, upon receiving a confirmation bus message, the bus node overwrites the non-volatile BND in its memory unit with the volatile BND. In other words, the confirmation bus message is received by the bus node via the communication bus. The confirmation bus message can confirm the volatile BND transmitted in the identification bus message. After a monitoring bus node of the bus communication system verifies the volatile BND in the identification bus message, the confirmation bus message can be sent. The volatile BND is then stored in the bus node's memory unit upon receipt of the confirmation bus message.The confirmation bus message can evaluate the transmitted active bus node identification value as valid. The active bus node identification value is then stored in the memory unit, thus confirming its validity. This further development offers the advantage that the validity of the volatile bus node identification value can be confirmed to the bus node via the confirmation bus message.
[0034] A further development of the procedure stipulates that if the non-volatile bus node identification value (BUS ID) has a second validity state, the bus node, in the specified BUS ID determination procedure, sets the volatile BUS ID as the active BUS ID. In other words, it is provided that if the non-volatile BUS ID has a second validity state, this non-volatile BUS ID is set by the bus node as the active BUS ID. The second validity state could, for example, describe that the stored non-volatile BUS ID was used in a previous communication session as 2020404697.
[0035] 8
[0036] It was rated as "valid". Therefore, it can initially be assumed that it is a non-volatile bus node identification value suitable as an active bus node identification value.
[0037] To verify the validity of the non-volatile bus node identification value, the bus node additionally determines its volatile bus node identification value using a predefined bus node identification procedure. In a further step, the bus node compares this determined volatile bus node identification value with its non-volatile bus node identification value and checks for consistency. This allows the system to determine whether the bus node has been installed in a different location since the previous communication session, if the volatile bus node identification value depends on the installation location. If the volatile bus node identification value is identical to the non-volatile bus node identification value, the non-volatile bus node identification value is maintained as the active bus node identification value.In other words, in this case, the bus node participates in the session using the bus node identification value.
[0038] In a further development of the invention, it is provided that if the volatile bus node identification value deviates from the non-volatile bus node identification value, the determination of the non-volatile bus node identification value as the active bus node identification value is canceled, and the non-volatile bus node identification value in the storage unit is overwritten by the volatile bus node identification value. In this case, the non-volatile bus node identification value must be overwritten to "invalid." The volatile bus node identification value can represent the determined bus node identification value based on the environmental detection value and is therefore generally within the valid range. However, without confirmation by the monitoring bus node, it is not used as the active bus node identification value for communication. In this case, the non-volatile bus node identification value is the non-2020404697.
[0039] 9
[0040] A temporary bus node identification value is stored, which is assigned to the third validity state, "invalid". This value can, for example, have a uniquely defined value that may be intended for this purpose.
[0041] This can occur, for example, if the bus node was installed in a different location during the preceding bus node identification procedure than at the time the bus node identification procedure was performed. In this case, the volatile bus node identification value is recorded as invalid. To enable the provision of a valid, active bus node identification value, it is provided that after the non-volatile bus node identification value in the memory unit is overwritten by the volatile bus node identification value, which has the third validity state "invalid," the bus node's participation in the session is terminated and the bus node initialization procedure is reinitialized.
[0042] A further development of the invention provides that, in a third validity state of the non-volatile bus node identification value, a volatile bus node identification value of the bus node is determined by the bus node in the specified bus node identification value determination procedure according to a specified bus node identification procedure, and an identification bus message, comprising the volatile bus node identification value of the bus node, is sent by the bus node via the communication bus.
[0043] In a further step, it is planned that upon receipt of the confirmation bus message, the non-volatile bus node identification value of the bus node is set as the active bus node identification value, and upon receipt of the confirmation bus message, the non-volatile bus node identification value in the storage unit is overwritten by the volatile bus node identification value. This allows the non-volatile bus node identification value to assume the validity state "valid". Furthermore, 2020404697
[0044] 10
[0045] Upon receiving the confirmation bus message, the bus node can participate in communication via the communication bus according to the standard procedure. The bus node can initiate or activate the participation of the bus node in the session.
[0046] A further development of the invention provides that the identification bus message is sent via the communication bus by the bus node after a delay time determined by the bus node using a random or pseudo-random method. This random delay statistically avoids collisions when sending the identification bus messages.
[0047] A further development of the invention provides that upon receiving a request message via the communication bus, the bus node restarts the process. In other words, the initialization process of the bus node is restarted when the bus node receives the request message. The request message can be sent via the communication bus, for example, if there is an inconsistency in the volatile bus node identification values determined by the bus nodes. This inconsistency can be detected, for example, by a monitoring bus node, which can receive the identification bus messages and compare the volatile bus node identification values provided therein.
[0048] A further development of the invention provides that the identification bus message, comprising the volatile bus node identification value of the bus node, is received by a monitoring bus node of the communication bus system via the communication bus. In other words, the communication bus system includes the monitoring bus node, which is designed to receive the identification bus message of the bus node via the communication bus. The monitoring bus node can be configured as a so-called master in the communication bus system. The volatile bus node identification value of the bus node is monitored by the monitoring bus node for a collision with a volatile
[0049] 11
[0050] The bus node identification value of another bus node is checked. In other words, the monitoring bus node checks the volatile bus node identification values transmitted via the identification bus messages for collisions. A specific time window may be provided for the monitoring bus node to receive the identification bus messages. Within this time window, the monitoring bus node can be configured to receive the identification bus messages from the communication buses and read the volatile bus node identification values of the respective identification bus messages. After the time window has elapsed, the monitoring bus node can be configured to determine whether at least two of the identification bus messages have transmitted identical bus node identification values, thus indicating a collision.In this case, it is intended that if a collision is detected, the request message is sent from the monitoring bus node to the communication bus in order to cause the bus nodes to restart the initialization process.
[0051] A further development of the invention provides that the monitoring bus node of the communication bus system compares the volatile bus node identification value of the bus node with expected bus node identification values. In other words, it is provided that certain bus node identification values are expected in the communication bus system. The monitoring bus node compares the received volatile bus node identification values with the expected bus node identification values to determine whether the bus node identification value in question matches one of the expected bus node identification values.If the bus node's transient bus identification value is collision-free and matches one of the expected bus node identification values, the monitoring bus node sends the confirmation bus message over the communication bus to inform the bus node of the validity of its transient bus node identification value. If the bus node's transient bus identification value does not match any of the expected values, the confirmation bus message is sent over the communication bus.
[0052] 12
[0053] If the bus node identification values do not match, the confirmation message may be omitted, or the relevant bus node identification value may be omitted from the confirmation bus message. The situation where the transient bus node identification value does not match one of the expected bus node identification values can occur, for example, if the bus node is located in an unintended installation position.
[0054] A further development of the invention provides that a diagnostic status of the communication bus system is stored by the monitoring bus node of the communication bus system. This diagnostic status includes collisions and deviations of the transient bus node identification values from the expected bus node identification values. For example, it can be provided that collisions that occur again after the process is repeated are stored as a diagnostic status. It can be documented, for instance, that the conflict exists at a specific installation position, where more than one of the nodes has the same bus node identification value. Furthermore, this diagnostic status can record the installation positions for which no identification bus message was received. For example, it can be recorded that the bus node with a specific expected bus node identification value is missing.The diagnostic status can also indicate that an identification bus message has been received containing a bus node identification value for which no corresponding expected bus node identification value exists. For example, an unexpected installation position might be present in this case. This diagnostic status can provide valuable information for vehicle diagnostics. A missing bus node in conjunction with a duplicate bus node indicates an error in the "PinCoding" coding procedure. This diagnostic status enables fault isolation within the communication bus system.
[0055] A further development of the invention provides that the communication bus system is configured as a CAN bus communication bus system. In other words, 2020404697
[0056] 13
[0057] The communication bus system is a system based on the CAN bus standard.
[0058] According to the CAN bus standard, collisions occur in the communication bus system when bus messages from different bus nodes have identical bus message identification values. The standard stipulates that the bus message identification value is derived from the active bus node identification value. This results in identical bus message identification values being determined for bus nodes using the same active bus node identification value. By applying this method, collisions in the communication bus system according to the CAN bus standard can be avoided.
[0059] A second aspect of the invention relates to a bus node that is configured to carry out a method for initializing a bus node of a communication bus system according to the first aspect of the invention.
[0060] The bus node includes a memory unit. The bus node is configured to read a non-volatile bus node identification value stored in the bus node's memory unit. The bus node is configured to determine the validity state of the bus node's non-volatile bus node identification value. The bus node is configured to set an active bus node identification value for individual identification of the bus node in a session via a communication bus according to a predefined bus node identification value determination procedure. The bus node is configured to execute the bus node identification value determination procedure depending on the validity state of the non-volatile bus node identification value. The bus node is configured to activate a communication state of the bus node for communication via the communication bus.
[0061] A third aspect of the invention relates to a monitoring bus node. 2020404697
[0062] 14
[0063] The monitoring bus node is configured to receive an identification bus message via a communication bus, containing a transient bus node identification value of a bus node, and to check this transient bus node identification value for a collision with a transient bus node identification value of another bus node. In the event of a collision, the monitoring bus node is configured to send a request message to the communication bus, requesting the bus nodes of the communication bus system to repeat an initialization process.
[0064] A fourth aspect of the invention relates to a communication bus system comprising at least two bus nodes according to the second aspect of the invention and a monitoring bus node according to the third aspect of the invention. The at least two bus nodes and the monitoring bus node can be interconnected for transmitting bus messages via a communication bus of the communication bus system. The communication bus system can, for example, be arranged in a vehicle, wherein the bus nodes can be sensor devices of a sensor system that can be mounted at predetermined installation positions on the vehicle.
[0065] To perform the described steps, a processor circuit can be provided in the bus node and the monitoring bus node. This processor circuit contains programming or software that includes program instructions which, upon execution of these instructions, cause the processor circuit to perform an embodiment of the method. The processor circuit can include at least one microprocessor and / or microcontroller. The program instructions can be stored in a data memory of the processor circuit.
[0066] The invention also includes further developments of the bus node according to the invention, the monitoring bus node according to the invention and the 2020404697
[0067] 15
[0068] The communication bus system according to the invention has features that have already been described in connection with the further developments of the method according to the invention. For this reason, the corresponding further developments of the bus node, the monitoring bus node and the communication bus system according to the invention are not described again here.
[0069] For use cases or application situations that may arise during the procedure and are not explicitly described here, it may be provided that, according to the procedure, an error message and / or a request for user feedback is issued and / or a default setting and / or a predetermined initial state is set.
[0070] The invention also includes combinations of the features of the described embodiments.
[0071] An embodiment of the invention is described below. The following is shown:
[0072] Fig. 1 shows a schematic representation of a communication bus system in a vehicle;
[0073] Fig. 2 shows a schematic representation of a method for initializing a bus node of a communication bus system at a first validity state of the non-volatile bus node identification value;
[0074] Fig. 3 shows a schematic representation of a method for initializing a bus node of a communication bus system during a second validity state of the non-volatile bus node identification value; and
[0075] Fig. 4 shows a schematic representation of a method for initializing a bus node of a communication bus system in a third validity state of the non-volatile bus node identification value. 2020404697
[0076] 16
[0077] The embodiment described below is a preferred embodiment of the invention. In this embodiment, the described components each represent individual features of the invention that can be considered independently of one another. Each of these features further develops the invention independently and can therefore be considered part of the invention individually or in a combination other than that shown. Furthermore, the described embodiment can also be supplemented by other features of the invention already described.
[0078] In the figures, functionally identical elements are each provided with the same reference symbols.
[0079] Fig. 1 shows a schematic representation of a communication bus system 10 in a vehicle 16.
[0080] The communication bus system 10 can, for example, be assigned to an environmental sensing system. The communication bus system 10 can conform to the CAN bus standard and be designed to enable communication between sensor devices 12 of the environmental sensing system, which can be arranged at respective installation positions 14 of the vehicle 16. The sensor devices 12 can be integrated into the communication bus system 10 as bus nodes 18. The sensor devices 12 can each have a sensor unit 20, which can be configured to detect the environment of the sensor device 12. The sensor unit 20 can be configured to determine an environmental detection value 22 at the installation position 14 of the sensor device 12, depending on the detected environment, which characterizes the environment of the sensor device 12. The environmental detection value 22 can uniquely identify the respective environment of the sensor device 12.
[0081] The bus nodes 18 are interconnected via a communication bus 24 of the communication bus system 10 and are equipped for sending and receiving bus messages 26 via the communication bus 24. 2020404697
[0082] 17
[0083] Since each of the bus nodes 18 is located in a specific environment, uniquely characterized by the environment detection value 22, a transient bus node identification value 28 can be derived for each of the bus nodes 18 based on the environment detection value 22. Each of the bus nodes 18 can be configured to send bus messages 26 via the communication bus 24, where a bus message identification value 30 can depend on an active bus node identification value 32 of the sending bus node 18. Likewise, each of the bus nodes 18 can be configured to determine the bus message identification values 30 of the bus messages 26 to be received by it based on the active bus node identification value 32.If at least two of the bus nodes 18 send bus messages 26 with identical bus message identification values 30, this can lead to a collision and a failure of the communication bus system 10. To prevent this, it is therefore necessary to ensure that, during a communication session, no bus message 26 is sent by more than one of the bus nodes 18 in the communication bus system 10 that has identical active bus node identification values 32.
[0084] To ensure this, the communication bus system 10 can have a monitoring bus node 34. Expected bus node identification values 36 of the communication bus system 10 can be stored in the monitoring bus node 34. The volatile bus node identification values 28 can be based on the environmental sensing value 22 acquired by the sensor unit 20.
[0085] The collision problem can occur, for example, if at least one of the bus nodes 18 is replaced during maintenance, or if the installation positions 14 of the bus nodes 18 are swapped during maintenance. Since the installation positions 14 of the bus nodes 18 can be predetermined in such a way that it can be deduced from the respective position which of the expected bus node identification values 36 occur in the system, these expected bus node identification values 36 can be in the2020404697
[0086] 18
[0087] Monitoring bus node 34 is provided. To prevent collisions, the respective bus node 18 is initialized. Initialization can describe a process for integrating bus node 18 into the communication via communication bus 24 of the communication bus system 10. The initialization process is designed to ensure that each of the bus nodes 18 uses its unique active bus node identification value 32 during the communication session. The active bus node identification value 32 used in the session is referred to as the active bus node identification value 32.
[0088] The initialization of bus node 18 can be initiated, for example, when bus node 18 is activated or when it receives a predefined signal via communication bus 24. Each bus node 18 has a memory unit 40 containing a non-volatile bus node identification value 38. This non-volatile bus node identification value 38 can be determined by bus node 18 in a previous initialization procedure. The non-volatile bus node identification value 38 can be configured to be assigned a validity state.For example, it may be provided that 38 value ranges are specified for the non-volatile bus node identification value, whereby the value ranges can be assigned to a respective validity state of the non-volatile bus node identification value 38.
[0089] The value ranges can be stored in the respective bus node 18, so that the respective bus node 18 is configured to compare the read non-volatile bus node identification value 38 with the value ranges and to determine the validity state of the non-volatile bus node identification value 38. It can be provided that bus nodes 18 that have not yet performed the initialization procedure have a specific non-volatile bus node identification value 38 in their storage unit 40 by default, through which the validity state of the non-volatile bus node identification value 38 is determined.
[0090] 19
[0091] The non-volatile bus node identification value 38 can be marked as "brand new". This value can, for example, be "0". In addition to the first validity state "brand new", a second validity state "valid" and a third validity state "invalid" can be provided for the non-volatile bus node identification value 38. The second validity state "valid" can be assigned to a value range that a detected non-volatile bus node identification value 28 can have due to its installation position 14. The third validity state "invalid" can be assigned to a specific value of the non-volatile bus node identification value 38.
[0092] Each bus node 18 is configured to determine the validity state of the non-volatile bus node identification value 38 of bus node 18 in the respective procedure for initializing bus node 18. Each bus node 18 is configured to define the active bus node identification value, which is used by bus node 18 for communication via communication bus 24. The active bus node identification value 32 can, for example, form the basis for the bus message identification values 30 of the bus messages 26 sent by bus node 18 via communication bus 24 and / or the bus messages 26 received by bus node 18 via communication bus 24.
[0093] The determination of the active bus node identification value 32 is carried out according to a predefined bus node identification value determination procedure.
[0094] The execution of the bus node identification value determination procedure depends on the validity status of the non-volatile bus node identification value 38 of bus node 18.
[0095] Bus node 18 can be configured to, in the event that the non-volatile bus node identification value 38 stored in its storage unit 40 has the first validity state, to issue a volatile bus node identification value 28 of bus node 18 according to a predefined 2020404697
[0096] 20
[0097] The bus node identification procedure is to be determined. The bus node identification procedure can, for example, include reading the environmental sensing value 22 from the storage unit 40 or performing an environmental sensing procedure using the sensor device 12 to determine the environmental sensing value 22. Based on the environmental sensing value 22, the bus node 18 can determine the volatile bus node identification value 28. The volatile bus node identification value 28 can be set as the active bus node identification value 32, which the bus node 18 can use for communication via the communication bus 24. Consequently, the bus node 18 can derive the bus message identification value 30 from the active bus node identification value 32.
[0098] The bus node 18 can send the non-volatile bus node identification value 38 in an identification bus message 42 via the communication bus 24 to announce the active bus node identification value 32 in the communication bus system 10.
[0099] The monitoring bus node 34 can be configured to receive the identification bus message 42 of the respective bus nodes 18 during a specified time window and to check the determined bus node identification values for a collision and compare them with the expected bus node identification values 36. If a collision occurs, i.e., at least two of the bus nodes 18 use identical active bus node identification values, the monitoring bus node 34 can send a request message 44 via the communication bus 24, thereby restarting the initialization procedure in each of the bus nodes 18.
[0100] If no collision occurs and the transient bus node identification value 28 matches one of the expected bus node identification values 36, a confirmation bus message 46 can be transmitted by the monitoring bus node 34, confirming the validity of the relevant non-transient 2020404697
[0101] 21
[0102] The bus node identification value 38 can be confirmed. Upon receipt of the confirmation bus message 46, the bus node 18 can overwrite the non-volatile bus node identification value stored in the memory unit 40 with the volatile bus node identification value 28.
[0103] If a non-volatile bus node identification value 38 is stored in bus node 18, which has a second validity state indicating a "valid" bus node identification value, bus node 18 may be configured to set the non-volatile bus node identification value as the active bus node identification value 32 for use in communication via communication bus 24. Bus node 18 may also be configured to simultaneously determine the volatile bus node identification value 28 of bus node 18 according to the specified bus node identification procedure and compare it with the non-volatile bus node identification value 38. If there is a match, communication can continue via bus node 18 based on the active bus node identification value 32.The bus node 18 can be configured, in the event that the volatile bus node identification value 28 and the non-volatile bus node identification value 38 differ, to overwrite the non-volatile bus node identification value 38 in the storage unit 40 with the non-volatile bus node identification value 28, which is assigned the third validity state "invalid", and to discontinue communication based on the active bus node identification value 32 and to restart the initialization procedure of the bus node 18.
[0104] Bus node 18 is configured to determine the volatile bus node identification value 28 of bus node 18 according to the specified bus node identification procedure if it detects that the non-volatile bus node identification value 38 is in the third validity state, which designates the non-volatile bus node identification value 38 as "invalid". The determined volatile bus node identification value 28 is then sent in the identification bus message 42 via communication bus 24. This involves a communication state of 2020404697
[0105] 22
[0106] Bus node 18 is deactivated to participate in regular bus communication in order to avoid collisions. Monitoring bus node 34 is configured to check the non-volatile bus node identification value 38 of bus node 18 in the confirmation bus message 46 and, if valid, to release it by means of the confirmation bus message 46. Upon receiving the confirmation bus message 46, bus node 18 is configured to set its non-volatile bus node identification value 38 as the active bus node identification value and to overwrite the non-volatile bus node identification value 38 in storage unit 40 with the volatile bus node identification value 28.
[0107] Fig. 2 shows a schematic representation of a method for initializing a bus node 18 of a communication bus system 10 at a first validity state of the non-volatile bus node identification value 38.
[0108] Fig. 2 shows a case in which the non-volatile bus node identification value 38 of bus node 18 has the first validity state.
[0109] In a first step A1, the bus node 18 can read the non-volatile bus node identification value 38 from a storage unit 40 of the bus node 18.
[0110] In a second step A2, bus node 18 can determine the validity state of the non-volatile bus node identification value, and bus node 18 can determine that the non-volatile bus node identification value has the first validity state. This allows bus node 18 to recognize that it is brand new and has not yet participated in any initialization process.
[0111] In accordance with the stored specifications, bus node 18 can determine its non-volatile bus node identification value 38 in a third step A3. This can be done, for example, by reading or activating a sensor unit 20 of bus node 18. For example, sensors of the 2020404697 can be used.
[0112] 23
[0113] Bus node 18 detects an environment and, depending on the nature of the environment, determines the environment detection value 22, from which the fleeting bus node identification value 28 is determined.
[0114] In a fourth step A4, the bus node 18 can determine the bus message identification value 30 based on its volatile bus node identification value 28, which identifies the bus messages 26 sent or received by the bus node 18.
[0115] Using the determined bus message identification value 30, bus node 18 can participate in communication via communication bus 24 in a fifth step A5.
[0116] In a sixth step A6, bus node 18 can send an identification bus message 42 via communication bus 24 to communicate the bus node identification value it has determined.
[0117] In a seventh step A7, the monitoring bus node 34 can receive the identification bus message 42 with the volatile bus node identification value 28 of bus node 18.
[0118] In an eighth step A8, the monitoring bus node 34 can compare the received non-volatile bus node identification value 38 of bus node 18 with other received non-volatile bus node identification values 38 of other bus nodes 18 and check for collisions.
[0119] If no collision occurs and the received non-volatile bus node identification value 38 of bus node 18 matches one of the expected bus node identification values, the monitoring bus node 34 sends a confirmation bus message 46 to bus node 18 in a ninth step A9, provided its bus node identification value is valid.
[0120] 24
[0121] In a tenth step A10, bus node 18 can receive the confirmation bus message 46 and in an eleventh step A11 store the volatile bus node identification value 28 in its storage unit 40, thereby overwriting the non-volatile bus node identification value 38 with the first validity state with the non-volatile bus node identification value 28 with a second validity state, which evaluates the non-volatile bus node identification value 28 as valid.
[0122] If, however, a collision is detected in the eighth step A8, a request message 44 can be sent from the monitoring bus node 34 via the communication bus 24 in a twelfth step A12.
[0123] The request message 44 can be received by the bus nodes 18 in a thirteenth step A13, which in turn causes them to restart the initialization procedure in a fourteenth step A14.
[0124] Fig. 3 shows a schematic representation of a method for initializing a bus node 18 of a communication bus system 10 during a second validity state of the non-volatile bus node identification value 38.
[0125] Fig. 3 shows a schematic representation of the sequence of an initialization procedure for a bus node 18 when the non-volatile bus node identification value 38 in the memory of the bus node 18 has a second validity state that evaluates it as valid. It may be provided that the non-volatile bus node identification value 38 exhibiting the second validity state was determined in a procedure shown in Fig. 2.
[0126] In a first step, B1 can read the non-volatile bus node identification value 38 from a storage unit 40 of bus node 18. 2020404697
[0127] 25
[0128] In a second step B2, it can be provided that the bus node 18 determines the validity state of the non-volatile bus node identification value 38, which evaluates the non-volatile bus node identification value 38 as "valid".
[0129] In a third step B3, it can be provided that bus node 18 sets the non-volatile bus node identification value 38 of bus node 18 as the active bus node identification value 32.
[0130] In a fourth step B4, the bus node 18 can determine the bus message identification values 30 for the bus messages 26 to be received and / or sent by the bus node 18 via the communication bus 24, based on the active bus node identification value 32.
[0131] In a fifth step B5, the bus node 18 can determine the fleeting bus node identification value 28 of the bus node 18 according to the specified bus node identification procedure, as described in connection with Fig. 2.
[0132] In a sixth step B6, bus node 18 can compare the volatile bus node identification value 28 of bus node 18 with the non-volatile bus node identification value 38 of bus node 18, whereby it is provided that it is determined whether the volatile bus node identification value 28 of bus node 18 matches the non-volatile bus node identification value 38 of bus node 18.
[0133] If a match is found, communication continues based on the active bus node identification value 32 (B7).
[0134] In case of a discrepancy, it is stipulated that in an eighth step (B8), communication between bus junction 18 and communication bus 24 will be terminated. 2020404697
[0135] 26
[0136] Furthermore, in a ninth step B9 in the storage unit 40, the non-volatile bus node identification value 38 is overwritten by the non-volatile bus node identification value 38, which has a third validity state that evaluates it as "invalid", so that in order to participate in the communication of the bus node 18 a valid bus node identification value must first be determined.
[0137] In a tenth step B10, it is therefore provided that the initialization procedure of bus node 18 of the communication bus system 10 is restarted.
[0138] Fig. 4 shows a schematic representation of a method for initializing a bus node 18 of a communication bus system 10 at a third validity state of the non-volatile bus node identification value.
[0139] Fig. 4 shows a schematic diagram of a procedure for initializing a bus node 18 into a third validity state. The bus node 18 can have a non-volatile bus node identification value 38, which is assigned to the third validity state. The non-volatile bus node identification value 38 of the third validity state can, for example, have been determined using a procedure shown in the preceding Fig. 3.
[0140] In a first step, C1 can read the non-volatile bus node identification value 38 from a storage unit 40 of the bus node 18.
[0141] In a second step C2, bus node 18 can determine the validity state of the non-volatile bus node identification value 38, which evaluates the non-volatile bus node identification value 38 as "invalid".
[0142] In this case, it may be provided that the relevant bus junction 18 is not included in normal communication via the 2020404697 to avoid a collision.
[0143] 27
[0144] Communication bus 24 is participating. For this reason, in a third step, communication bus 24 can be switched offline (C3).
[0145] Due to the assessment of the non-volatile bus node identification value 38 as "invalid", it is therefore necessary to first determine a valid bus node identification value for bus node 18.
[0146] In a fourth step C4, it is provided that the volatile bus node identification value 28 of bus node 18 is determined according to the specified bus node identification procedure, as described in connection with the preceding figures.
[0147] In a fifth step C5, the identification bus message 42, which contains the volatile bus node identification value 28 of bus node 18, is sent via the communication bus 24.
[0148] In a sixth step C6, the monitoring bus node 34 can receive the identification bus message 42 and, as described in Fig. 2, check it in a seventh step C7.
[0149] If valid, the monitoring bus node 34 can send the confirmation bus message 46 in an eighth step C8 to confirm the active bus node identification value of bus node 18.
[0150] In a ninth step, bus node 18 can receive the confirmation bus message 46 via the bus and set the non-volatile bus node identification value 38 as the active bus node identification value 32.
[0151] In a tenth step, C10, bus node 18 can store the non-volatile bus node identification value 38 in memory unit 40. 2020404697
[0152] 28
[0153] Subsequently, bus node 18 can determine the bus message identification values 30 of the bus messages 26 and participate in communication via the communication bus 24 (C11 ).
[0154] If, however, a collision is detected in the seventh step C7, a request message 44 can be sent from the monitoring bus node 34 via the communication bus 24 in a twelfth step C12.
[0155] The request message 44 can be received by the bus nodes 18 in a thirteenth step C13, which can cause them to restart the initialization process in a fourteenth step C14.
[0156] The invention relates to a situation in which identical bus nodes 18 in a communication bus system 10 according to the CAN bus standard participate in a session via a communication bus 24. The identical bus nodes 18 behave identically due to the same software. However, the communication bus system 10 according to the CAN bus standard requires the definition of unique bus node identification values for the participating bus nodes 18 to prevent physical collisions of transmitted bus messages 26 signals on the communication bus 24. The definition of these unique bus node identification values can be achieved through external physical influences in identical communication buses. Examples include voltage values at the pins of a connector of the respective bus nodes 18, metal plates and HAL sensor units 20 of the respective bus nodes 18, or secondary communication interfaces for calibration.
[0157] Due to its complexity, the assignment of unique bus node identification values during manufacturing and spare parts transactions is usually not a one-time process, but rather is re-entered after each system restart (reset). If an incorrect assignment occurs, meaning two identical bus nodes receive the same bus node identification value, a CAN "Bus-off" error will occur. This error recurs periodically due to the timeout defined in the CAN bus standard and attempts to... (2020404697)
[0158] 29
[0159] Bus node 18 needs to return to "online" status. Because this conflict between bus node 18, which has the same bus node identification values, affects communication bus 24, other bus nodes on bus 18 cannot communicate normally, and diagnostics using the UDS standard are not always possible.
[0160] One aspect of the invention is to non-volatilely store a bus node identification value "lastD" on the structurally identical bus nodes 18, which can occur multiple times in the communication bus system 10. This identification value can be divided into three value ranges: Brand New, Valid, or Invalid. After the bus node 18 is woken up, a case distinction is made based on the three value ranges.
[0161] In the case of "brand new", an identification process is performed, and the newly obtained, volatile bus node identification value 28 "neuelD" is used to register the identifiers (CAN IDs) for receiving and sending bus messages 26 by bus node 18. This bus node 18 also sends an identification bus message 42 to the communication bus 24, indicating that it has accepted "neuelD" as the active bus node identification value. Another of the bus nodes 18 assumes the role of the monitoring bus node 34. This monitoring bus node 34 knows the bus node identification values that are supposed to be present in the vehicle 16 and their physical installation position 14 in the vehicle 16. The monitoring bus node 34 collects all identification bus messages 42 from the bus nodes 18 over a defined period and checks whether there is a conflict between the active bus node identification values.In the event of a conflict, monitoring bus node 34 sends a request message on communication bus 24, which causes all bus nodes 18 to re-execute the process for evaluating their bus node identification value. This repetition in the event of a conflict ensures that only responses from bus nodes 18 are considered that do not originate from a state prior to the deletion of an ID identified as invalid (see 2. Below; transition: "valid" to "invalid"). Monitoring bus node 34 then confirms all 2020404697.
[0162] 30
[0163] Identification messages that do not conflict with a confirmation bus message 46. The monitoring bus node 34 can enter a "DiagnosticTroubleCode" for each position to which the missing identification value is assigned. Upon receiving the confirmation bus message 46, each bus node 18 can check whether its "newId" has been confirmed. If so, the "newId" is transferred to the non-volatile "lastId". Thus, the identification value changes from the "Factory New" range to the "Valid" range. 2. In the case of "Valid", bus node 18 evaluates the non-volatile identification value "lastId" upon waking and, based on this, registers the CAN IDs for receiving and sending. Furthermore, this bus node 18 is then ready for communication and participates in bus communication as usual. Simultaneously, bus node 18 starts the new identification process and receives the new identification value "newId" upon completion.This leads to a case distinction when comparing "lastID" with "newID". If this comparison ends with "identical", no action is required. If this comparison ends with "different", the non-volatile identification value "lastID" is set to "Invalid" and the TRX performs a reset. 3. In the case of "Invalid", the identification is performed and the newly received identification value "newID" is used to send information to the bus after a timeout, indicating that it has accepted a "newID". Bus node 18 does not participate in regular bus communication to avoid conflicts on the bus. Bus node 18 waits for a confirmation bus message from the monitoring bus node 34. If this message is received and the "newID" is confirmed, the "newID" can be transferred to the non-volatile "lastID". Additionally, the CAN IDs for receiving and sending are registered based on the "newID".From this point on, bus node 18 participates in regular bus communication again. Based on the feedback from bus node 18 regarding its ID evaluation and the system configuration, monitoring bus node 34 is able to derive the following diagnostic information: a) Bus node 18 not expected (feedback of an unconfigured position) b) Bus node 18 missing (no feedback) c) Bus node 18 inconsistent (multiple, inconsistent feedback). Bus participants that are not involved in the conflict can, with a high degree of probability, continue to participate regularly.
[0164] 31
[0165] Communication can take place on the bus. Furthermore, a bus node 18 can evaluate which bus node 18 is causing an error. In the case of a valid, non-volatile identification value, the bus participant's readiness to communicate is restored much sooner than if the identification had to be re-evaluated. This principle can be transferred and applied to other bus or network topologies, such as LIN and Ethernet.
[0166] Overall, this example demonstrates how to ensure CAN communication even if two identical CAN bus participants are misidentified. 2020404697
[0167] 32
[0168] Reference symbol list
[0169] 10 Communication bus system
[0170] 12 Sensor device
[0171] 14 installation positions
[0172] 16 vehicles
[0173] 18 bus junctions
[0174] 20 sensor units
[0175] 22 Environment detection value
[0176] 24 Communication bus
[0177] 26 Bus News
[0178] 28 volatile bus node identification value
[0179] 30 Bus message identification value
[0180] 32 active bus node identification value
[0181] 34 monitoring bus nodes
[0182] 36 Expected bus node identification value 38 Non-volatile bus node identification value 40 Storage unit
[0183] 42 Identification bus message
[0184] 44 Request bus message
[0185] 46 Confirmation bus message
[0186] A1-A14 Procedure steps
[0187] B1-B10 Procedure steps
[0188] C1-C13 process steps
Claims
2020404697 33 Patent claims 1. Procedure for initializing a bus node (18) of a communication bus system (10), characterized by the fact that through the bus junction (18): - a non-volatile bus node identification value (38) of the bus node (18) stored in a memory unit (40) of the bus node (18) is read out; - a validity state of the non-volatile bus node identification value (38) of the bus node (18) is determined; - an active bus node identification value (32) for the individual identification of the bus node (18) in a communication via a communication bus (24) is determined according to a predefined bus node identification value determination procedure, wherein the bus node identification value determination procedure depends on the validity state of the non-volatile bus node identification value (38); and - a communication state of the bus node (18) for communication via the communication bus (24) is activated using the active bus node identification value (32).
2. The method according to claim 1, characterized in that in a first validity state of the non-volatile bus node identification value (38) by the bus node (18) in the specified bus node identification value determination procedure, - a transient bus node identification value (28) of the bus node (18) is determined according to a predefined bus node identification procedure; and - the transient bus node identification value (28) of the bus node (18) is set as the active bus node identification value (32).
3. Method according to claim 2, characterized in that 2020404697 34 in the first validity state of the non-volatile bus node identification value (38) by the bus node (18) in the specified bus node identification value determination procedure, - an identification bus message (42) comprising the volatile bus node identification value (28) of the bus node (18) is sent via the communication bus (24); and - the non-volatile bus node identification value (38) in the storage unit (40) is overwritten by the volatile bus node identification value (28) upon receipt of the confirmation bus message (46).
4. The method according to claim 1, characterized in that in a second validity state of the non-volatile bus node identification value (38) by the bus node (18) in the specified bus node identification value determination procedure, - the non-volatile bus node identification value (38) of the bus node (18) is set as the active bus node identification value (32); - a transient bus node identification value (28) of the bus node (18) is determined according to a predefined bus node identification procedure; and - the volatile bus node identification value (28) of bus node (18) is compared with the non-volatile bus node identification value of bus node (18); - if the volatile bus node identification value (28) matches the non-volatile bus node identification value (38), the non-volatile bus node identification value (38) of bus node (18) is determined to be the active bus node identification value (32).
5. The method according to claim 4, characterized in that The specified bus node identification value determination procedure, in the event of a deviation of the volatile bus node identification value (28) from the non-volatile bus node identification value (38), comprises the following steps: 2020404697 35 - Overwriting the non-volatile bus node identification value (38) in the storage unit (40) with a non-volatile bus node identification value (38) of a third validity state; and - Re-initiating the procedure to initialize the bus node (18) of the communication bus system (10).
6. The method according to claim 1, characterized in that in a third validity state of the non-volatile bus node identification value (38) by the bus node (18) in the specified bus node identification value determination procedure, - a transient bus node identification value (28) of the bus node (18) is determined according to a predefined bus node identification procedure; and - an identification bus message (42) comprising the volatile bus node identification value (28) of the bus node (18) is sent via the communication bus (24); and - the non-volatile bus node identification value (38) of the bus node (18) is set as the active bus node identification value (32) upon receipt of the confirmation bus message (46), and the non-volatile bus node identification value (38) in the memory unit (40) is overwritten by the volatile bus node identification value (28) upon receipt of the confirmation bus message (46), and a communication state of the bus node (18) is activated for communication via the communication bus (24) using the active bus node identification value (32).
7. Method according to claim 6 of the preceding claims, characterized in that the identification bus message (42) is sent via the communication bus (24) after a delay time determined by the bus node (18) by a random or pseudo-random method.
8. Method according to one of the preceding claims, characterized in that upon receipt of a 2020404697 36 The request message (44) is sent through the bus node (18) via the communication bus (24) and the procedure is restarted.
9. Method according to any of the preceding claims, characterized in that through a monitoring bus node (34) of the communication bus system (10) the identification bus message (42), comprising the volatile bus node identification value (28) of the bus node (18), is received via the communication bus (24); - the volatile bus node identification value (28) of bus node (18) is checked for a collision with a volatile bus node identification value (28) of another bus node (18); and - in the event of a collision, the request message (44) is sent to the communication bus (24), which includes a request to repeat the procedure by the bus nodes (18) of the communication bus system (10).
10. The method of claim 9, characterized in that through the monitoring bus node (34) of the communication bus system (10) - the volatile bus node identification value (28) of the bus node (18) is compared with expected bus node identification values (36); and - to send the confirmation bus message to the communication bus (24) if the volatile bus node identification value (28) of the bus node (18) is collision-free and also matches one of the expected bus node identification values (36).
11. The method of claim 10 with reference to claim 9, characterized in that a diagnostic status of the communication bus system (10) is stored by the monitoring bus node (34) of the communication bus system (10), wherein the diagnostic status of the communication bus system (10) includes the collisions and deviations of the transient bus node identification values (28) from the expected bus node identification values (36). 37 12. Method according to one of the preceding claims, characterized in that the communication bus system (10) is set up as a CAN communication bus system (10).
13. Bus junction (18), characterized by the fact that the bus junction (18) is designed to, - to read a non-volatile bus node identification value (38) of the bus node (18) stored in a storage unit (40) of the bus node (18); - to determine a validity state of the non-volatile bus node identification value (38) of the bus node (18); - to define an active bus node identification value (32) for the individual identification of the bus node (18) in a communication via a communication bus (24) according to a predefined bus node identification value determination procedure, wherein the bus node identification value determination procedure depends on the validity state of the non-volatile bus node identification value (38); and - to activate a communication state of the bus node (18) for communication via the communication bus (24) using the active bus node identification value (32).
14. Monitoring bus node (34) characterized by the fact that the monitoring bus node (34) is configured to receive an identification bus message (42) comprising a transient bus node identification value (28) of the bus node (18) via the communication bus (24); - to check the volatile bus node identification value (28) of bus node (18) for a collision with a volatile bus node identification value (28) of another bus node (18); and2020404697 38 - in the event of a collision, to send the request message (44) to the communication bus (24), which includes a request to repeat the procedure by the bus nodes (18) of the communication bus system (10).
15. Communication bus system (10) characterized by the fact that the communication bus system (10) comprises at least two bus nodes (18) according to claim 13 and a monitoring bus node (34) according to claim 14.