ETHERNET COMMUNICATION OF CAN SIGNALS
A vehicle can use controlled area network (CAN) buses for communications within a subsystem but connect different subsystems using Ethernet connections. For example, a network interface (NIC) of a subsystem can receive a CAN message from a CAN bus and incorporate the CAN message into a user diagram protocol (UDP) message which can be then packaged into an Ethernet packet. The UDP message may include a table of contents (TOC). The TOC may include the message ID and the length of the CAN message. Once a NIC receives the message, the receiving NIC can extract the UDP message from the Ethernet packet, parse through the TOC to identify a CAN message relevant to the control units of the receiving NIC's subsystem, extract the relevant CAN message based on the TOC, and put the CAN message onto CAN buses to be sent to destination CAN devices.
1 . A vehicle comprises:
a plurality of vehicle operating subsystems;
a first plurality of electronic control units (ECUs) communicatively coupled to a first network communication bus associated with a first subset of the plurality of vehicle operating subsystems, wherein the first plurality of ECUs is configured to communicate over the first network communication bus with messages formatted according to a first network protocol;
a second plurality of ECUs communicatively coupled to a second network communication bus associated with a second subset of the plurality of vehicle operating subsystems, wherein the second plurality of ECUs is configured to communicate over the second network communication bus with messages formatted according to the first network protocol;
a first network interface communicatively coupled to the first network communication bus;
a second network interface communicatively coupled to the second network communication bus;
the first network interface and the second network interface are communicatively coupled to a third network communication bus, wherein the first network interface and the second network interface are configured to communicate over the third network communication bus with messages formatted according to a second network protocol;
wherein the first network interface is configured to:
receive first messages from the first plurality of ECUs via the first network communication bus;
incorporate the first messages into a packet formatted according to the second network protocol; and
send the packet to the plurality of vehicle operating subsystems; and
wherein the second network interface is configured to:
receive the packet from the third network communication bus;
parse the packet to extract second messages with addresses associated with the second plurality of ECUs;
reformat the second messages according to the first network protocol; and
deliver the second messages to the second plurality of ECUs via the second network communication bus.
2 . The vehicle of claim 1 , wherein the first network communication bus and the second network communication bus comprise buses for controller area networks (CAN) and wherein the third network communication bus comprises a bus for an Ethernet network.
3 . The vehicle of claim 2 , wherein the first messages and the second messages are CAN signals and the first network protocol is a CAN protocol.
4 . The vehicle of claim 2 , wherein the second network protocol is a user datagram protocol (UDP).
5 . The vehicle of claim 4 , wherein the packet comprises a table of contents (TOC) which comprises addresses and lengths of the first messages.
6 . The vehicle of claim 5 , wherein to parse the packet to extract second messages with addresses associated with the second plurality of ECUs, the second network interface is configured to:
parse through the TOC; and
identify an address and a position of a message of the second messages based on the TOC.
7 . The vehicle of claim 6 , wherein to identify the position of the message, the second network interface is configured to:
identify one or more messages preceding the message in the packet; and
using the TOC, calculate a start position of the message based on lengths of the one or more messages.
8 . The vehicle of claim 1 , wherein the second messages comprise a subset of the first messages.
9 . The vehicle of claim 1 , wherein the packet is encrypted.
10 . The vehicle of claim 1 , wherein the packet includes a control message for controlling at least one of: the first network interface or the second network interface.
11 . A method for communication among a plurality of vehicle operating subsystems, the method comprising:
establishing first communications among a first plurality of electronic control units (ECUs) in a vehicle and between the first plurality of ECUs and a first network interface, wherein the first communications are via a first network communication bus associated with a first subset of the plurality of vehicle operating subsystems and the first plurality of ECUs communicates over the first network communication bus with messages formatted according to a first network protocol;
establishing second communications among a second plurality of electronic control units (ECUs) in the vehicle and between the second plurality of ECUs and a second network interface, wherein the second communications are via a second network communication bus associated with a second subset of the plurality of vehicle operating subsystems and the second plurality of ECUs communicates over the second network communication bus with messages formatted according to the first network protocol;
establishing third communications between a first network interface and a second network interface via a third network communication bus with messages formatted according to a second network protocol;
receiving, by the first network interface, first messages from the first plurality of ECUs via the first network communication bus;
incorporating, by the first network interface, the first messages into a packet formatted according to the second network protocol; and
sending, by the first network interface, the packet to the plurality of vehicle operating subsystems; and
receiving, by the second network interface, the packet from the third network communication bus;
parsing, by the second network interface, the packet to extract second messages with addresses associated with the second plurality of ECUs;
reformatting, by the second network interface, the second messages according to the first network protocol; and
delivering, by the second network interface, the second messages to the second plurality of ECUs via the second network communication bus.
12 . The method of claim 11 , wherein the first network communication bus and the second network communication bus comprise buses for controller area networks (CAN) and wherein the third network communication bus comprises a bus for an Ethernet network.
13 . The method of claim 12 , wherein the first messages and the second messages are CAN signals and the first network protocol is a CAN protocol.
14 . The method of claim 12 , wherein the network second protocol is a user datagram protocol (UDP).
15 . The method of claim 14 , wherein the packet comprises a table of contents (TOC) which comprises addresses and lengths of the first messages.
16 . The method of claim 15 , wherein parsing the packet to extract second messages with addresses associated with the second plurality of ECUs comprises:
parsing through the TOC; and
identifying an address and a position of the message of the second messages based on the TOC.
17 . The method of claim 16 , wherein identifying the position of the message comprises:
identifying one or more messages preceding the message in the packet; and
using the table of contents, calculating a start position of the message based on lengths of the one or more messages.
18 . The method of claim 11 , wherein the second messages comprise a subset of the first messages.
19 . The method of claim 11 , wherein the packet is encrypted.
20 . The method of claim 11 , wherein the packet comprises a control message for controlling at least one of: the first network interface or the second network interface.