Ethernet for automotive
Ethernet for automotive
Like other general networks, it is just a collection of computers that exchange data.
Overview of in-vehicle network
Each company uses its own standards.
| the company | standard |
|---|---|
| Universal | Class 2 |
| Chrysler | CCD(Chrysler Collision Detection) |
| Ford | - SCP(Standard Corporate Protocol) |
| Toyota | BEAN(Body Electronic Area Network) |
Later, CAN developed by Bosch realized the industry standard.
| years | event |
|---|---|
| 1983 | Bosch started development internally |
| 1986 | Officially announced @美国SAE |
| 1987 | The first CAN controller leaves the factory |
| 1992 | Adopted by Mercedes-Benz |
| 1993 | As ISO11898 international standardization |
| 1998 | Due to the merger of Daimler and Chrysler, it has also become popular in the United States. |
CAN overview
Compared with the previous communication method, it has the following advantages.
| aspect | content |
|---|---|
| low cost | Mass production effect brought by double lines and international standardization |
| high speed | Maximum 1 Mbps |
| High noise immunity & high reliability | Error detection function, etc. |
| Easy to use | Add/remove nodes without affecting other nodes |
CAN-FD overview
In order to cope with the increasing amount of communication in recent years where CAN is increasingly insufficient, Bosch released CAN-FD in 2012.
| CAN | CAN-FD | |
|---|---|---|
| Maximum communication speed | 1Mbps | 8Mbps |
| Maximum payload | 8 bytes | 64 bytes |
Advantages of CAN-FD ≈ Advantages of CAN
LIN overview
| advantage | Disadvantage |
|---|---|
| Cheaper than CAN: only 1 wire, using UART | Low speed: 19.2 Kbps@40m |
| Data error detection, node failure detection | Up to 16 nodes |
| Delay guarantee |
Overview of FlexRay
| advantage | Disadvantage |
|---|---|
| High-speed communication up to 10 Mbps | We need to design and fix the entire network in advance |
| High reliability (ensure 2 redundant data channels) | High cost |
| High-precision message delay control | |
| Corresponding to multiple topologies (bus type/star type/mixed type) |
MOST overview
| advantage | Disadvantage |
|---|---|
| High-speed communication up to 150 Mbps | 1 failure caused the overall decline |
| Plug and play: self-identification and automatic initialization function of the device | Optical fiber is expensive and not easy to bend |
| Use optical fiber to reduce weight & anti-noise & zero noise radiation |
Types and trends of in-vehicle Ethernet
| IEEE 802.3 100BASE-TX Ethernet | BroadR-Reach Ethernet | Reduced Pair Gigabit Ethernet |
|---|---|---|
| ～2014 | 2014~ | 2020～ |
| 100Mbps | 100Mbps | 1Gbps |
| Diagnosis/ECU Falsh | Driving assistance/infotainment | network backbone |
Use case 1: DoIP (diagnosed via Ethernet)
Use case 2: XCP on Ethernet
Use case 3: Driving assistance
Use case 4: Infotainment
Use case 5: On-board network backbone
