In-vehicle network management using virtual networks

• US 6,484,082 B1
• Filed: 05/24/2000
• Issued: 11/19/2002
• Est. Priority Date: 05/24/2000
• Status: Expired due to Term

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: General Motors Corporation (Motors Liquidation Co. GUC Trust)
• Inventors: Millsap, Arnold W., Anderson, Anthony, Forest, Thomas Michael, Nakis, George D, Hansson, Peter H. G.
• Primary Examiner(s): LOUIS JACQUES, JACQUES H
• Application Number:
  US09/578,213
• Time in Patent Office: 909 Days
• Field of Search: 701/36, 701/48, 701/1, 340/438, 340/439, 340/825.22, 340/825.16, 340/825.06, 340/458, 340/462, 709/221, 709/224, 709/233, 709/245, 709/100, 709/106, 709/200, 709/201, 710/107, 710/110, 307/10.1, 307/9.1, 370/241, 370/242, 370/245, 370/254, 370/257, 702/182, 702/183
• US Class Current: 701/48
• CPC Class Codes: H04L 12/40039 Details regarding the setting of the power status of a node according to activity on the bus
• CPC Class Codes: H04L 12/4035 in which slots of a TDMA packet structure are assigned based on a contention resolution carried out at a master unit TDM/TDMA multiplex systems per se H04J3/1694; hybrid switching systems H04L12/64
• CPC Class Codes: H04L 12/4625 Single bridge functionality, e.g. connection of two networks over a single bridge
• CPC Class Codes: H04L 12/4641 Virtual LANs, VLANs, e.g. virtual private networks [VPN] LAN interconnection over a bridge based backbone H04L12/462; encapsulation techniques H04L12/4633; routing of packets H04L45/00; packet switches H04L49/00; virtual private networks for security H04L63/0272
• CPC Class Codes: H04L 2012/40273 the transportation system being a vehicle

Abstract

A network management approach for use in a vehicle to control activation of electronic control units (ECUs) networked together throughout the vehicle. The ECUs are grouped together by function into virtual networks, with each virtual network including those ECUs used in carrying out a particular control task, such as controlling power windows or automatic headlights. The virtual networks are activated using a messaging protocol that specifies which virtual network is being activated. Periodic messages specifying the virtual network are also used to maintain it active. This permits the ECUs to be maintained in a low power quiescent state when the control functions are not needed, while allowing only those needed for a particular control task to be awakened and maintained in an activated state to carry out their associated control task. An ECU can activate one of the virtual networks by transmitting a wake-up signal followed by a message identifying the virtual network. Each of the ECUs receive this message and, if it is a member of the virtual network being initialized, maintains itself in an active state to carry out the control task associated with the virtual network. The other ECUs return to the quiescent state. Using this approach, an ECU is able to activate only the necessary ECUs for a particular control task without having to know which or how many ECUs are involved in performing the task.

Claims

1. An on-board vehicle network, comprising:

a plurality of on-board vehicle electronic control units (ECUs) connected together via at least one network bus that permits communication between said ECUs;

a first virtual network comprising a first group of said ECUs, wherein said first group of said ECUs are operable together to perform a first control task and are each identified using a first code that is associated with said first virtual network; and

a second virtual network comprising a second group of said ECUs, wherein said second group of said ECUs are operable together to perform a second control task and are each identified using a second code that is associated with said second virtual network;

wherein said ECUs of said first and second virtual networks are connected to said network bus to receive first and second messages, with said ECUs of said first virtual network being responsive to said first message to perform said first control task and said ECUs of said second virtual network being responsive to said second message to perform said second control task;

wherein a first one of said ECUs is connected to said network bus to receive a first signal requesting activation of said first virtual network and is operable in response to said first signal to periodically generate said first message until said first control task is completed; and

wherein a second one of said ECUs is connected to said network bus to receive a second signal requesting activation of said second virtual network and is operable in response to said second signal to periodically generate said second message until said second control task is completed.

2. An on-board vehicle network as defined in claim 1, wherein said first message includes said first code.

3. An on-board vehicle network as defined in claim 2, wherein said first code comprises a bit located in a selected position within said first message.

4. An on-board vehicle network as defined in claim 3, wherein said first message includes a plurality of different bit positions, each of which corresponds to a different virtual network and each of which can be set or cleared to indicate whether its associated virtual network is active or inactive.

5. An on-board vehicle network as defined in claim 2, wherein said first one of said ECUs is in said first virtual network and wherein said first message further includes data that identifies said one ECU.

6. An on-board vehicle network as defined in claim 1, wherein said first one of said ECUs is operable to generate said first message within a first time slot and wherein said second one of said ECUs is operable to generate another message within a second time slot that is different than said first time slot.

7. An on-board vehicle network as defined in claim 6, wherein said first and second messages comprise virtual network messages and wherein each ECU on said network bus is assigned a unique ID that is used to determine a time slot for that ECU, with each said ECU using its associated time slot for transmissions of said virtual network messages.

8. An on-board vehicle network as defined in claim 7, wherein the number of time slots is less than the number of ECUs on the network bus, whereby at least some of said ECUs use a time slot that is the same as others of said ECUs.

9. An on-board vehicle network as defined in claim 1, wherein said first code is the same for all of the ECUs in said first virtual network.

10. An on-board vehicle network as defined in claim 1, wherein said first and second codes each comprise a code that uniquely identifies its associated virtual network from all other virtual networks connected to said vehicle bus.

11. An on-board vehicle network as defined in claim 1, wherein at least one of said ECUs is a multiple task ECU that is included in both said first and second groups, whereby said multiple task ECU comprises a part of both said first and second virtual networks.

12. An on-board vehicle network as defined in claim 1, further including a third virtual network comprising a third group of said ECUs, wherein said third group of said ECUs are operable together to perform a third control task and are each identified using a third code that is associated with said third virtual network.

13. An on-board vehicle network as defined in claim 1, wherein one or more of said ECUs are operable in both an active state and a low power quiescent state and are operable to switch from said quiescent state to said active state in response to a wake-up signal sent by another of said ECUs.

14. An on-board vehicle network as defined in claim 13, wherein said first one of said ECUs is operable to generate said wake-up signal and to thereafter generate said first message.

15. An on-board vehicle network as defined in claim 14, wherein, following switching from said low power quiescent state to said active state, each of said one or more ECUs are operable to monitor for one of said messages and are operable to return to said low power quiescent state if no message is received identifying a virtual network containing the ECU.

16. An on-board vehicle network as defined in claim 1, wherein said first virtual network includes only those ECUs used in carrying out said first control task.

17. An on-board vehicle network as defined in claim 1, wherein said ECUs within said first group are operable upon reset to perform the first control task.

18. An on-board vehicle network as defined in claim 1, wherein said first message is transmitted over said network bus at a regular interval until said first control task is complete and wherein the ECUs in said first virtual network are operable to monitor said network bus for a predetermined amount of time following receipt of each first message, with said predetermined amount of time being greater than said interval.

19. An on-board vehicle network as defined in claim 1, wherein said first message includes at least one bit that distinguishes an initial transmission of said first message from subsequent transmissions of said first message.

20. An on-board vehicle network as defined in claim 1, wherein said first virtual network is activated as a result of said first message and wherein each of said ECUs of said first group are operable following a reset and upon receiving one of the subsequent transmissions of the first message to send a message over said network bus that re-initializes said first virtual network.

21. An on-board vehicle network as defined in claim 1, further comprising a second network bus connected to said one network bus via a gateway, wherein said gateway is operable to transmit said first message to said second network bus.

22. An on-board vehicle network as defined in claim 21, wherein said first message includes an sub-net ID identifying said one network bus.

23. A method of managing an on-board vehicle network of electronic control units (ECUs), wherein at least some of the ECUs are operable in both an active state and a low power quiescent state and wherein the network includes at least one subset of the ECUs that are operable together to perform a particular control task, the method comprising the steps of:

(a) receiving a signal request for activating a control task;

(b) waking up the ECUs out of the low power quiescent state;

(c) sending a message to the ECUs that includes a code associated with the control task;

(d) wherein each of a number of the ECUs perform the steps of;

(d1) receiving the message and,

(d2) if the code included with the message corresponds to a control task associated with the ECU, then operating in an active state in which the ECU is operable to perform the control task together with other ECUs associated with the control task; and

(d3) if the code included with the message does not correspond to a control task associated with the ECU, then entering into the low power quiescent state.

24. The method of claim 23, wherein:

step (a) further comprises having one of the ECUs receive the signal request;

step (b) further comprises having that one ECU send out a wake-up signal to other ECUs on the network; and

step (c) further comprises having that one ECU send the message to other ECUs on the network.

25. The method of claim 24, wherein the message includes data that uniquely identifies that one ECU.

26. The method of claim 23, wherein the code identifies a virtual network that includes the ECUs associated with the control task to which the code corresponds.

27. The method of claim 23, wherein step (c) further comprises sending a message having a code for each of a plurality of control tasks.

28. The method of claim 27, wherein each of the codes within the message comprise a bit located in a different position within the message, whereby each of the plurality of control tasks is associated with one of the bits within the message.

29. The method of claim 23, wherein step (b) further comprises, for each of a number of the ECUs, waiting a period of time for receipt of the message and, in the absence of receipt of that message, entering into the low power quiescent state following elapse of the period of time.

30. The method of claim 23, wherein step (c) further comprises periodically sending a follow-up message to the ECUs, wherein said follow-up messages including the code.

31. The method of claim 30, wherein, for those ECUs associated with the code contained in the messages, the method further comprises the steps of:

waiting a period of time for receipt of one of the messages;

entering into the low power quiescent state if none of the messages is received within a selected period of time; and

if one of the messages is received within the selected period of time, then continuing in the active state and repeating said waiting, entering, and continuing steps.

32. The method of claim 31, further comprising the step of resetting a timer following receipt of each of the messages and entering the low power quiescent state upon expiration of the timer.

33. The method of claim 32, further comprising the steps of receiving a signal indicative of a low-voltage condition and halting operation of the timer until the low-voltage condition is no longer indicated.

34. A method of operating an electronic control unit (ECU) that is included within an on-board vehicle network of ECUs, comprising the steps of:

(a) operating in a low-power quiescent state;

(b) receiving a wake-up signal via the network;

(c) switching to an active state in response to the wake-up signal;

(d) monitoring the network for receipt of a code indicative of a control task to be carried out using a number of the ECUs on the network;

(e) switching back to the quiescent state if no code is received within a period of time following the wake-up signal; and

(f) if a code is received within the period of time, then performing the steps of;

(f1) determining whether the ECU is associated with the code;

(f2) if so, enabling operation of the ECU to support carrying out the control task; and

(f3) if not, switching back to the quiescent state.