Mentor Automotive Vehicle Network Design to meet the needs of ADAS and Autonomous Driving Presented to AESIN Conference 2016 By Martin Wennberg October 2016
Abstract With the new automotive trends such as highly automated driving and car-2-x communication the demands on the communication design for a car is changed drastically. New aspects such as redundancy, security and cloud interaction are mixed with the traditional communication design, increasing the need of advanced network design tool support. This presentation will provide an overview of the new communication needs as well as give an introduction to service oriented communication (e.g. SOME/IP) and aspects to consider when mixing it with the traditional signal based communication. 2 - Confidential
MENTOR AUTOMOTIVE OVERVIEW Connectivity and Networking In-car Experience Technology and Subsystems EE Architecture Electrical Distribution Infotainment Driver information Thermal Analysis LED Lighting Harness Engineering AUTOSAR Methodologies System Engineering Noise Cancellation Electronics Cooling PCB Design Communications Networks Cyber Security ADAS & AD Automotive Audio Bus Multi-Domain 3 - Confidential The tux mascot is attributed to Larry Ewing and the GIMP. The Automotive Audio Bus is a registered trademark of Analog Devices, Inc.
Important Automotive Trends Electric Vehicles Eco-Driving Autonomous Vehicles V2X / Connectivity Architecture Security Image Courtesy Continental Corp. BOM cost 4 - Confidential
MULTIPLE NETWORK TECHNOLOGIES Complex in-car systems need to communicate with each other: Traditional LIN, CAN, and FlexRay combines with new automotive protocols like Ethernet and CanFD IVI Driver Info ADAS AD ECU ECU Cameras Sonar/Radar LIN CAN ECU CAN ECU ECU Ethernet ECU ECU Redundant ECU Gateway ECU Gateway ECU CAN/Ethernet Secure SOTA Ethernet / FlexRay Backbone 5 - Confidential
Why redundancy, security and cloud interaction A Highly automated driving need backup systems in case something goes wrong Service based communication is one solution Connected cars have multiple new entry point Multiple, layered protection mechanisms should be incorporated to secure the connected car. Data encryption is one. Cloud interaction move communication outside the car Ethernet is established outside of the car 6 - Confidential
Benefits Of Ethernet High bandwidth at moderate cost Protocols out of the box (UDP, TCP or AVB) Easily connect to external networks High industry know-how 7 - Confidential
Ethernet As Backbone Connects multiple domains Signal based communication Data or Service oriented Stream based communication eavb streams Different modes might need to be supported Download/On charger/driving Signal gatewaying to/from traditional field buses CAN/Lin/Flexray PDUs and signals 8 - Confidential
Ethernet New communication Paradigm CAN, FlexRay Ethernet Communication channel Shared Switched Configuration Static Static and/or dynamic Scalability New buses New link Message size Small to medium Big Overhead Small Relative big Bandwidth Limited 1Gbits/s Analysis OK Complicated 9 - Confidential
Signal based Communication: Data vs. Service Oriented Communication Data Oriented Easy distribution of data Data transformation or signal mapping can be used Using signals and groups only Compatible with CAN/FR Service Oriented Communication is per client SOME/IP transformer must be used Using call/return messages Does not fit with CAN/FR ECU 1 ECU 2 ECU 1 ECU 2 SWC 1 SWC 2 SWC 1 SWC 2 ECU 3 SWC 3 ECU 3 SWC 3 10 - Confidential
How to use signal based Ethernet? Use Data oriented communication when connecting traditional field buses for periodically updated data for many consumers of the same data User Service oriented communication within an Ethernet cluster for sporadic communication between few nodes 11 - Confidential
Ethernet influence on ECU CPU load Ethernet allows more data to be sent Ethernet controllers does not do HW filtering like CAN Ethernet have higher overhead Service based communication uses call/return Ethernet typically does not broadcast data -> If not designing Ethernet carefully the ECU CPU load is likely to increase 12 - Confidential
Ethernet influence on Gateways Most OEMs will mix service- and signal-oriented communication Gateways likely need to handle both Gateways are already today heavily loaded Ethernet to Ethernet GW is not recommended -> The Ethernet topology design is important 13 - Confidential
Ethernet timing requirements Timing requirements are important for both signal based and service based communication Service based communication uses call/return communication Client call server, server process request and return value -> Even if Ethernet is quick a service oriented request might take time if not properly designed 14 - Confidential
Ethernet Switch configuration Switch typically part of the ECU Semi static configuration Learning and static configuration MAC=tier1 and IP=OEM Several queues (port buffers) per port Queues have priorities (QoS, AVB, VLAN) Traffic shaper: forms queues content Scheduler: decides from which queue to send next frame Weighted Round Robin (WRR) Strict Priority (SP) -> Configuring an Ethernet switch is complicated Source: 17_Rick_Kreifeldt_- _Harman_International_AV nu.pdf 15 - Confidential
Capturing Communication Design Working with Documents Working with VSA COM Signals/Streams Link Utilization Busload, CPU Latencies, buffers Compatibility Downstream?????????????????? Signals/Streams Link Utilization Busload, CPU Latencies, buffers Compatibility Downstream 16 - Confidential
Summary Traditional and service based communication will co-exist Increased data communication is increasing CPU load on ECUs Automotive Ethernet is complex to design Understanding Ethernet is not the same as understanding automotive (AUTOSAR) Ethernet Advanced network design tool support is even more important for the coming generation of cars 17 - Confidential
m e n t o r. c o m / a u t o m o t i v e
Physical Networks BUS CAN CAN FD LIN FLEXRAY ETHERNET Speed Up to 1 Mbps Up to 8 Mbps Up to 19.2 Kbps 10 Mbps Up to 1 Gbps Cable Type Twisted Pair 5V Twisted Pair 5V Single Wire 12V 2 or 4 Wires One or more Twisted Pair Cost $$ $$ $ $$$$ $$$ Applications ABS, Powertrain, Engine Control Higher data capacity CAN applications Electric Seats, Mirror, Tailgate Steering, Traction Control, Active Suspension IP Cameras, Radar, Infotainment 19 - Confidential