EP2735124A1

EP2735124A1 - Method and apparatus for storing an item of wake-up information in subscribers of a can bus system

Info

Publication number: EP2735124A1
Application number: EP12735859.6A
Authority: EP
Inventors: Tobias Lorenz; Karsten Wehefritz
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 2011-07-19
Filing date: 2012-07-12
Publication date: 2014-05-28
Also published as: DE102011079412A1; WO2013010900A1; US20140245052A1; US9557803B2

Abstract

The invention presents an apparatus for connecting a subscriber station to a CAN bus, wherein the subscriber station in the active state can interchange messages according to the ISO 11898 standard with other subscriber stations via the CAN bus using the apparatus, wherein the subscriber station in the quiescent state can be activated using the apparatus upon the reception of an item of wake-up information, wherein the item of wake-up information has the structure of a CAN message according to the ISO 11898 standard, wherein suitable first means are provided in the apparatus in order to selectively evaluate the received item of wake-up information, with the result that the wake-up operation is initiated only when an item of wake-up information which is predefined or can be predefined for the respective subscriber station is present, which apparatus is characterized in that storage means are provided in the apparatus in order to completely or partially store the item of wake-up information evaluated for the wake-up operation if the latter is initiated.

Description

Description title

Method and device for storing alarm information in

Participants of a CAN bus system

State of the art

The invention is based on a method and a device for

Wake up participants in a CAN bus system according to the preambles of the independent claims.

For example, from the standards of the family ISO 11898-1 to -5 the Controller Area Network (CAN) and an extension of the CAN called "Time Triggered CAN" (TTCAN) are known

Media access control is based on bitwise arbitration. The subscriber stations can begin simultaneously to transmit a message over the bus. The transmitted messages have an identifier which is transmitted immediately after a single "Start of Frame" bit In bitwise arbitration, the subscriber stations can simultaneously determine the logic state (0 or 1) of the bus when transmitting the bits associated with the identifier. If the value of a bit transmitted by a first subscriber station does not correspond to the determined logical state of the bus, another subscriber station has evidently sent a message with a higher priority and the first subscriber station therefore terminates the transmission access to the bus reaches that message over the bus that wins the arbitration process. With the increasing electronization of modern vehicles and the introduction of additional systems to improve, for example, driving safety or driving comfort, the requirements for the consumption of electrical energy are constantly growing. At the same time, there is a need to limit energy consumption in order to meet environmental and legislative requirements. Against the background of the increasing introduction of electrically driven vehicles, it is appropriate to reduce the energy consumption by the control, regulation, safety, and

Comfort systems, as the electrical energy consumed directly affects the available vehicle range.

Therefore, it is provided in new vehicles to put individual bus users or groups of bus subscribers in whole or in part to a state of rest, if the function exercised by them or the respective

Partial functionality is not needed. This is accompanied by the requirement that bus subscribers located in the idle state can be purposefully re-awakened or activated, in whole or in part, when the function or sub-functionality that is at rest is required again.

The patent application DE 103 58 584 AI discloses in this context an apparatus and a method for selectively waking participants of a bus system, in which a detection means, in particular a counter is provided which detects at least a predetermined signal property of the signals transmitted on the bus system and upon reaching a predetermined number initiates the further wake-up process.

The patent application DE 102 25 578 AI discloses a method and apparatus for selective activation of bus subscribers, which is characterized by providing a separate voltage regulator for the present in the bus subscriber protocol controller. In this way, when bus communication occurs, the protocol controller without the associated application controller can first be awakened, which is then available for comparing the messages present on the bus with one or more reference messages stored in advance. If there is a match Subsequently, the application controller and thus the entire bus user awakened.

Disclosure of the invention

In the mentioned devices from the prior art, after the wake-up process, the information by which signal or message the alarm was triggered, no longer exists. This can be disadvantageous, especially if different messages are to lead to different properties of the awakened bus subscriber. For example, if different wake-up messages are to be used to wake up different sub-functionalities, the prior art does not provide satisfactory results in every respect, since after the wake-up process no information about the content of the message, which has led to the awakening is available. This information could be at

Presence be used to the wake-up depending on the reason of

Wake up, so depending on the requested functionality, adapt.

Based on the cited prior art, the present invention is therefore based on the object of providing a possibility for further providing the content of the successful alarm information after the wake-up process has been completed. This object is achieved by the device and the associated method according to the independent claims. In the following the invention will be described with its advantages with reference to drawings and exemplary embodiments. Advantageous features are described by the dependent subclaims. The object of the invention is not limited to the illustrated and described embodiments. Advantages of the invention

In an advantageous application, a door control unit in a motor vehicle could contribute to a partial functionality of various vehicle functionalities, such as the functionality of the central locking operation of the door lock, an automatic to certain security functionalities Close the window, or to Konnfortfunktionalitäten a certain

Exterior mirror adjustment such. the automatic folding. Depending on the current state of the vehicle, different of these functionalities are activated. For example, could the central locking above a

certain limit speed are switched off, or one

Security functionality can only be activated above a speed threshold. A comfort functionality such as the folding of the exterior mirrors could, for example, only be executable in the state. Accordingly, different sub-functions or contributions of the door control unit are therefore required depending on the vehicle condition and under suitable conditions, the door control unit can be completely put into a state of rest. It makes sense to activate subfunctions separately when waking up the door control unit. For this purpose, it is advantageous if the door control unit information is present, by which wake-up message or for which functionality of the wake-up was performed.

Another example is parking systems whose functionalities must be provided differently depending on the vehicle condition. For example, the sensors and the evaluation control unit usually at

Engage the reverse gear fully activated. In the normal

Driving, however, the sensors are depending on the speed

possibly not at all or only partially needed, such as for measuring a parking space or for monitoring the blind spot, and the

The evaluation control unit must execute deviating or restricted functionalities. Here, too, it may therefore be useful to be able to separately activate partial functions of the parking system starting from the idle state. Again, it is advantageous if the parking control device is the information by which wake-up message or for which functionality of the wake-up was performed.

Further advantageous applications of the device according to the invention in the vehicle are also conceivable.

Based on a method and a device for waking participants in a CAN bus system from the prior art, in which suitable first means are provided for selectively evaluating the received wake-up information, and in which the wake-up operation is initiated only when a wake-up information predetermined or specifiable for the respective subscriber station is present, it is advantageous for the device according to the invention to provide storage means in the event that the wake-up process is initiated to store all or part of the alarm information evaluated for this purpose.

It is furthermore advantageous that suitable further means are provided in the device, so that different partial functionalities of the subscriber station and / or different application controllers and / or different operating modes of the at least one application controller are activated depending on the stored alarm information.

These further means can be set up in such a way that read access to the stored alarm information is made available to at least one application controller of the subscriber station. This achieves rapid availability of the wake-up information for the application controller.

In another embodiment, the further means can also be set up so that the stored alarm information is the

Communication controller is supplied. As a result, the wake-up information reaches the application controller with a time delay as a normal bus message, which reduces the complexity of setting up the method in the application controller.

In the case described last, the further means comprise at least one coder for converting the stored alarm information into a serial input signal for the communication controller. A changeover switch to

Switching the input signal to the communication controller between the signal present on the bus and the serial signal generated by the encoder is advantageous in order to avoid collisions between incoming bus signals and the alarm information provided by the encoder at the input of the encoder

Communication Controller to avoid.

The first means, which are provided to selectively evaluate the received alarm information, advantageously comprise a decoder comprising the serial message enters a receive memory area, said receive memory area, a filter storage unit and a comparison unit. In this way, a faster and safer comparison of the received message with the entries of the filter storage unit is possible.

drawings

The invention will be explained in more detail with reference to the drawings.

FIG. 1 schematically shows a bus system with bus subscribers having the device according to the invention.

Figure 2 shows a simplified block diagram of an inventive

Contraption.

Figure 3 shows a second embodiment of the alarm message memory, which is an essential element of the present invention.

Figure 4 shows a second embodiment of the alarm message memory, which is an essential element of the present invention.

Description of the embodiments

FIG. 1 shows a bus system 100 with four bus users 110, 120, 130, 140. Each bus subscriber has a device 111, 121, 131, 141 according to the invention, by means of which he is connected to the bus line. The

Device is in communication with a communication controller designated 112, 122, 132, 142. In addition, the various bus users have application controllers, which are designated 113, 123, 124, 134, and 145. The application controllers are in this example to

Execution of one or more functions set up, and belong to one or more subnets. Each subnet serves in this context to provide a certain functionality in the vehicle network. In the example shown here, the application controllers 113 and 123 together provide the functionality A, the application controllers 124 and 134 together provide the functionality B and the application controller 145 alternatively the functionality C or D. Of course, in another embodiment, an application controller could also contribute to several functionalities.

The advantage of the present invention can be illustrated by the example of the bus subscriber 120: If it is assumed that the functionalities A and B are not required under certain conditions, the bus subscriber can be switched off or put into an idle state in these driving situations since he does not is needed. If a situation now occurs in which the functionality A is required, one of the active bus subscribers, for example the subscriber 110, sends a wake-up message. Bus subscriber 120 is in idle state. Its bus connection unit 121, which represents the device according to the invention, observes the message traffic on the bus at rest. It analyzes the received wake-up message and determines that it is relevant for bus subscriber 120

Wake-up message is. Accordingly, it activates the

Communication controller 122 and one or more application controller. Furthermore, it makes the content of the received wake-up message available in a dedicated memory area. Because of that

Wake-up information is available in the bus subscriber, only the selective

Application controller 123, which for the execution of the functionality A.

is required to be woken up while the application controller 124 remains idle.

Using the example of the bus subscriber 140, a further possible use of the device according to the invention can be represented: as already shown, the application controller 145 can alternatively execute the functionality C or D. Starting from a situation in which neither of the two functionalities is required, the bus subscriber 140 is in the idle state. If a situation occurs in which the functionality C is required, then ship

Bus participants a corresponding wake-up message, which by the

Inventive device 141 is evaluated in the bus subscriber 140 and stored according to the invention in a suitable memory area. Of the Application controller 145 is started and can now the stored

Evaluate or read in alarm information and record the associated functionality C. If the functionality D is requested, a deviating alarm message is sent and stored according to the invention. The application controller 145 evaluates the stored alarm information or it is supplied to it by the device 141 according to the invention, and as a result it assumes the different functionality D.

FIG. 2 shows a simplified block diagram of an exemplary embodiment of the device 121 according to the invention. It contains a core piece

Control unit 210, which includes the waking unit 220. The control unit 210 is in connection with three interface units 230, 240 and 250, which in the present example in each case the interfaces to a

Application controller, to a communication controller and to a

Represent voltage regulator. The associated ports are exemplified by SPI, TxD, RxD, and INH. One or more of these

Interface units may also be provided multiple times in other embodiments if, for example, several application controllers are in communication with the control unit 210 or the wake-up unit 220. The control unit 210 is furthermore connected to the reception unit 260 and to the transmission unit 270. These are in turn connected to the bus lines of the bus system 100. Finally, the control unit also has a local wake-up connection, which is designated LWU.

In the normal operating mode, the device 121 receives bus signals via the receiving unit 260 and sends them serially to the communication controller via the interface unit 240 and the line RxD. In the transmission case, the device receives on the line RxD serial signals from the communication controller and transmits them via the transmitter unit 270 to the bus lines. in the

Idle state of the bus subscriber, for example, only the receiving unit 260 and the control unit 210 with the wake-up unit 220 is active. Wake-up of the bus subscriber is possible by means of various wake-up signals: for example, the bus subscriber can be activated by the local wake-up connection. Of interest to the present invention is the awakening by a

Bus message. If a message is received at rest, it will forwarded via the receiving unit 160 to the wake-up unit 220, there decoded and stored in whole or in part and compared with one or more predetermined wake-up message. If there is a match, the bus user is woken up by the interface unit 250 and the INH connection, which is connected by a suitable means, for example a

Voltage regulator is connected.

The fact that the alarm information was stored and for the

Bus subscriber is available, the wake-up process can be made depending on the content of the alarm information. Thus, for example, depending on the alarm information, different application controllers can be activated or different functions can be executed by the application controller. This can be implemented, for example, by triggering two voltage regulators 250 via the interface unit 250, which wake up two application controllers by supplying them with voltage. Alternatively, two interface units can be provided for this purpose. Each of the application controllers during the wake-up process or after its completion queries the contents of the memory area containing the alarm information.

If, depending on the alarm information, different application controllers are activated, then the active state is maintained if they match, while if the application controller in question does not match, the application controller in question again assumes a standby state, for example by issuing a command for

Shut down the supply voltage via a suitable interface to the responsible voltage regulator. Should depend on the

Alarm information on the application controller or different functions are activated as a contribution to certain vehicle functionality, so the active state of all application controllers is maintained, but it depends on the content of the memory area, the

Contains alarm information, one or more of which

Application Controllers run different programs.

Figure 3 shows an embodiment of the schematic structure of the wake-up unit 220, which means for the inventive storage Wake-up information includes. The from the receiving unit 260 serially

The received wake-up message is decoded in a decoding unit 340 provided for this purpose and stored in the receive memory area 330. It is also possible to store only parts of the wake-up message, provided that these parts comprise the components necessary for the evaluation and restoration of the wake-up information. The filter memory area 310 contains filter information, which includes, for example, the possible predetermined wake-up messages or the relevant components. A comparison of the received message in the receive memory area 330 with the filter information from the filter memory area 310 is performed in the comparison unit 320 set up for this purpose. If the result is positive, ie if the received message is one of the predetermined wake-up messages, the wake-up process takes place on the one hand, for example an activation of the voltage regulator via the interface 250. On the other hand, the wake-up message recognized as valid in the receive memory area 330 will be included in the intended purpose

Wake-up information storage area 350 transferred. In the illustrated

Embodiment variant, the application controller via the interface 230 direct access to the alarm information storage area 350th Die

Alarm information can therefore be read out and evaluated by the application controller. In this way, the application controller obtains information about the alarm information, which has led to the awakening, and can execute corresponding reactions, for example activating specified sub-functions and / or waking up other application controllers and / or again assuming a rest state.

A readout of the receive memory area 330 by the

In contrast, the application controller in order to obtain information about the wake-up information which has led to waking has the disadvantage that the receive memory area 330 can be overwritten by subsequently received messages which are not relevant to the bus subscriber

Display alarm messages. By transferring the alarm information in the wake-up information storage area 350 after successful verification by the comparison unit 320, on the other hand, the advantageous effect is achieved that the application controller, the message which for waking the Bus subscriber has continued to be available even after the arrival of further messages on the bus.

FIG. 4 shows a further exemplary embodiment of the schematic structure of the wake-up unit 220. In this case, there is no direct access of the

Application controller to the alarm information storage area 350 via the interface 230, but the alarm information stored there is serialized again by a coding unit set up 360 and via the switch 370 and the interface unit 240 to the

Communication controller or its RxD input serially transmitted. As usual, the communication controller forwards the contained information to the application controller. In this case, the application controller thus receives the wake-up information stored in the wake-up information memory area 350 after the wake-up process has been delayed as an ordinary message via the communication controller, whereby

Additional effort to set up the direct access from the application controller to the alarm information storage area 350, which is necessary in the embodiment of Figure 3, is eliminated. This is in the example of Figure 3 the

Application controller, the alarm information usually faster available than is the case in the embodiment of Figure 4. The two options are to be weighed against this background against each other.

Claims

claims

1) Device for connecting a subscriber station to a CAN bus, wherein the subscriber station can exchange messages in the active state by means of the device via the CAN bus with other subscriber stations according to the standard ISO 11898,

wherein the subscriber station at rest by means of the device at

Reception of a wake-up information can be activated

wherein the alarm information has the structure of a CAN message according to the standard ISO 11898,

wherein suitable first means (220) are provided in the apparatus for selectively evaluating the received wake-up information,

so that the wake-up process is initiated only in the presence of a predetermined or specifiable alarm information for the respective subscriber station, characterized in that

at least one alarm information memory area (350) is provided in the device in order, in the event that the wake-up process is initiated, to store all or part of the alarm information evaluated for this purpose.

2) Device according to claim 1,

characterized in that

in the device suitable further means are provided so that depending on the stored alarm information different application controller and / or different functions of the at least one

Application Controllers are activated.

3) Device according to claim 2,

characterized in that

the further means are arranged so that at least one

Application controller of the subscriber station read access to the stored Wake-up information is provided.

4) Device according to claim 2,

characterized in that

the other means are arranged so that the stored

Alarm information can be supplied to the communication controller.

5) Device according to claim 4,

characterized in that

the further means comprise at least one encoder (360) for converting the stored alarm information into a serial input signal for the communication controller.

6) Device according to claim 5,

characterized in that

the further means comprise at least one switch (370) for switching the input signal for the communication controller between the signal present on the bus and the serial signal generated by the encoder (360).

7) Device according to one of the preceding claims,

characterized in that

the first means at least one decoding unit (340), a

Receive memory area (330), a filter memory unit (310) and a comparison unit (320).

8) A method for waking up a subscriber station on a CAN bus, wherein the subscriber station in the active state can exchange messages with other subscriber stations in accordance with the standard ISO 11898 via the CAN bus,

wherein the subscriber station in the idle state upon receipt of a

Wake-up information can be activated,

wherein received alarm information is selectively evaluated, so that the wake-up process is initiated only in the presence of a predetermined or specifiable alarm information for the respective subscriber station, characterized in that

in the event that the wake-up process is initiated for the subscriber station, the alarm information evaluated for this purpose is stored in whole or in part.

9) Method according to claim 8,

characterized in that

depending on the stored alarm information different

Sub-functionalities of the subscriber station and / or different

Application controller and / or different operating modes of the at least one application controller can be activated.

10) Method according to claim 9,

characterized in that

at least one application controller of the subscriber station read access to the stored alarm information is provided.

11) Method according to claim 9,

characterized in that

the stored alarm information can be supplied to the communication controller.

12) Method according to claim 11,

characterized in that

the stored alarm information the communication controller by means of at least one encoder for the implementation of the stored

Alarm information in a serial input signal for the

Communication controller is supplied.

13) Method according to claim 12,

characterized in that

the stored Weckinformation the communication controller by means of at least one switch for switching the input signal for the Communication controller between the signal present on the bus and the coder generated by the serial signal is supplied.

14) Method according to one of claims 8 to 13,

characterized in that

received alarm information using at least one decoder, a receiving memory area, a filter storage unit and a comparison unit are selectively evaluated.