Virtual controller area network
View Patent ↗According to an embodiment of the present disclosure, a virtual controller area network system includes first, second third controller area network (CAN) buses. A first CAN controller is coupled to the first and second CAN buses and is configured to route messages to and from the first and second CAN buses. A second CAN controller is coupled to the third CAN bus and is configured to route messages to and from the third CAN bus. A network bridging system is configured to route messages over a local area network between the first CAN controller and the second CAN controller.
1. A virtual controller area network system comprising:
a first controller area network (CAN) bus coupled to a first plurality of CAN nodes;
a second CAN bus coupled to a second plurality of CAN nodes;
a third CAN bus coupled to a third Plurality of CAN nodes;
a first CAN controller coupled to the first and second CAN bus and configured to route messages to and from the first and second CAN bus;
a second CAN controller coupled to the third CAN bus and configured to route messages to and from the third CAN bus; and
a network bridging system configured to route messages over a local area network between the first CAN controller and the second CAN controller;
wherein (i) the first, second and third plurality of CAN nodes each have a unique identifier, (ii) the first, second and third CAN buses each have a CAN bus identifier associated with a virtual area network and that is used by the network bridging system to route the messages over the local area network, and (iii) messages are transmitted between CAN nodes on a common virtual area network using a combination of the unique identifier and the CAN bus identifier.
2. The virtual controller area network system of claim 1 , wherein the local area network utilizes an Ethernet protocol.
3. The virtual controller area network system of claim 1 , wherein the network bridging system includes a first Automotive Bridge to Ethernet (ABE) coupled to the first CAN controller and a second ABE coupled to the second CAN controller, wherein the first and second ABEs are configured to encapsulate the CAN bus identifier into an Ethernet frame for transmission over an Ethernet network.
4. The virtual controller area network system of claim 3 , wherein the network bridging system further includes a first Ethernet switch coupled to the first ABE and a second Ethernet switch coupled to the second ABE, wherein the first and second Ethernet switches are configured to transmit and receive Ethernet frames.
5. The virtual controller area network system of claim 4 , wherein the first CAN controller is configured to determine whether received messages should be terminated based on criteria that include (1) a destination node of a respective message does not have a message object allocated, (2)the destination node's allocated message object is not enabled for reception, (3) the received message is not valid, (4) a direction configured in the destination node's message object does not match the direction in the received message, (5) a number of bits of a message ID of the received message is greater than a number of bits that the destination node is configured to accept, (6) the received message has an error, and (7) a message ID in the received message is outside a range of acceptable values configured in the receiving destination node's message object.
6. The virtual controller area network system of claim 4 , wherein
the first and third CAN buses are associated with a virtual bus having a CAN bus identifier (ID),
the first controller is configured to receive, from a source node on the first CAN bus, a message along with a message ID identifying a destination node that is on the third CAN bus;
the first ABE is configured to the encapsulate the message and the message ID and the bus ID into an Ethernet frame; and
the first Ethernet switch is configured to transmit the Ethernet frame through the Ethernet.
7. The virtual controller area network system of claim 4 , wherein
the second Ethernet switch is configured to receive the frame from the Ethernet and forward the frame to the second ABE;
the second ABE is configured to extract the message and the message ID and the CAN bus ID from the frame, and enqueue the message into the second controller; and
the second controller is configured to transmit the message on the third bus for receipt by the destination node identified by the message ID.
8. The virtual controller area network system of claim 4 , wherein;
the first and second CAN bases are associated with a virtual bus having a CAN bus identifier (ID);
the first CAN controller is configured to receive a CAN message that is sent by a sending node that is on the first CAN bus;
the first ABE is configured to
extract the received message,
encapsulate the received message and the CAN bus ID in an Ethernet frame, and
transmit the Ethernet frame to a port on the first Ethernet switch;
the Ethernet switch is configured to receive the Ethernet frame and transmit the Ethernet frame back to the first ABE; and
the first ABE is further configured to
receive the Ethernet frame,
extract the CAN message and the message ID, and
enqueue the extracted CAN message onto the first CAN controller; and
the first CAN controller is configured to transmit the message on the second CAN bus.
9. The virtual controller area network system of claim 4 , wherein the first, second and third CAN buses have the same assigned bus IDs.
10. The virtual controller area network system of claim 1 , wherein two or more of the first, second and third CAN buses have different baud rates.
11. The virtual controller area network system of claim 1 , wherein the first, second and third CAN buses are included within subsystems of an automotive system.
12. A method for broadcasting messages in a virtual controller area network, comprising:
associating a plurality of physical controller area network (CAN) buses to form a virtual CAN bus, wherein the virtual CAN bus includes a first plurality of CAN buses coupled to a first CAN controller and a second plurality of CAN buses coupled to a second CAN controller, wherein the CAN buses associated with the virtual CAN bus share a common CAN bus identifier, and wherein each CAN bus is coupled to a plurality of CAN nodes;
receiving, at the first CAN controller, a message broadcast from a first CAN node on one of the first plurality of CAN buses;
encapsulating the message into an Ethernet frame along with the common CAN bus identifier and a CAN node identifier that identifies a second CAN node on one of the second plurality of CAN buses;
transmitting the Ethernet frame over a local area network from the first CAN controller to the second CAN controller using the common CAN bus identifier;
extracting the message from the Ethernet frame;
broadcasting the extracted message over the second plurality of CAN buses along with the CAN node identifier; and
receiving the extracted message at the second CAN node based on the CAN node identifier.
13. The method of claim 12 , wherein the local area network utilizes an Ethernet protocol.
14. The method of claim 12 , further comprising:
the first CAN controller determining, according to a preset filter, whether the message should be accepted or terminated.
15. The method of claim 14 , further comprising:
the first CAN controller determining whether received message should be terminated based on criteria that include (1) a destination node of a respective message does not have a message object allocated, (2) the destination node's allocated message object is not enabled for reception, (3) the received message is not valid, (4) a direction configured in the destination node's message object does not match the direction in the received message, (5) a number of bits of a message ID of the received message is greater than a number of bits that the destination node is configured to accept, (6) the received message has an error, and (7) a message ID in the received message is outside a range of acceptable values configured in the receiving destination node's message object.
16. The method of claim 12 , wherein the CAN bus identifier is inserted into one of a can_bus_id field of an IEEE 1722 ACF message header, a stream_id field of an IEEE 1722 AVTPDU header, an Ethernet destination address, an Ethernet source address, or an Ethernet VLAN label.