J1939: Opening Up AUTOSAR to the Heavy Vehicle Industry

Transcription

1 6th Vector Congress Stuttgart November, 2012 J1939: Opening Up AUTOSAR to the Heavy Vehicle Industry Bob Niemczyk,

2 Volvo Group Brands 2

3 Vertical or Horizontal Organization? Volvo Europe: New FH Truck Announced 9/2012 Fully Distributed Architecture Vertically-Integrated vehicle AUTOSAR / VAP compliant Volvo North America Plus many other HV OEMs: Semi-Vertical Integration High population of Vendor (non-oem) components SAE J1939 is the control protocol of choice 3

4 SAE J1939 Heavy Vehicle component manufacturers especially those concerned with the North American market have adopted J1939 as their control protocol of choice. Components range from engines, transmissions and safety systems to smart sensors and telematics devices. 4

5 just some of the companies on the SAE J1939 Committees: We all have to and do work together! 5

6 SAE J1939 and AUTOSAR A low-level of SAE J1939 integration in an AUTOSAR 3 environment is quite manageable. However, North America and some other markets have quite high and unpredictable levels of non-oem components and aftermarket add-ons. More than simple, periodic message exchange All ECUs cannot be known at configuration time All J1939 messages cannot be known at configuration time SAE J1939 is a Recommended Practice not a Standard 6

7 SAE J1939 and AUTOSAR 3 SAE J1939 AUTOSAR 3 7

8 AUTOSAR In its basic form, AUTOSAR is a signal-based communication layer: Full CAN ID must be specified (pre compile configuration of the full definition of the message and transport media required) Data is extracted from the messages and presented to the application software 8

9 SAE J1939 In its basic form, SAE J1939 is a messagebased communication protocol The CAN ID contains useful information to the system: Parameter Group Number (PGN) defines the content Communication partners: Source Address (Destination Address) Priority helps facilitate message access to the bus 9

10 SAE J1939 CAN-ID SOF 1 CAN-ID 29 RTR 1 Control 6 Data Field 0-64 CRC 16 ACK 2 EOF 7 PGN 21 Source Address 8 Priority 3 Reserved 1 Data Page 1 PDU Format 8 PDU Specific 8 10

11 SAE J1939 CAN-ID SOF 1 CAN-ID 29 RTR 1 Control 6 Data Field 0-64 CRC 16 ACK 2 EOF 7 PGN 21 Source Address 8 Priority 3 Reserved 1 Data Page 1 PDU Format 8 PDU Specific 8 11

12 Some SAE J1939 Protocol Features Message Priority Access to communication partner information (Source and Destination Addresses) Request / Response Large message transmission schemes Network Management J1939 Diagnostics Legislated Enhanced 12

13 SAE J1939 Message Priority The Priority is a 3 Bit field in the CAN ID With SAE J1939, the Priority bits are NOT allowed to be used in incoming message filtering. Why? SAE J , 5.2.1: These three bits are used to optimize message latency for transmission onto the bus only. They should be globally masked off by the receiver (ignored). AUTOSAR 3 requires defining all CAN ID bits. 13

14 Access to Communication Partners SAE J1939 messages all contain Source Addresses ( and some have Destination Addresses). Vehicle configurations change. Components are added or removed after manufacture. Source Address information can be critical to the application software: TorqueSpeedControl EBS More AUTOSAR 3 currently removes and discards this information. 14

15 Request / Response In addition to regularly broadcast messages, J1939 has the facilities to send non-broadcast messages on request similar to RequestDataByIdentifier. Some examples are: Engine Configuration Component ID Make and Model However, AUTOSAR 3 does not support this functionality. 15

16 Network Management All J1939 messages have a Source Address. There are only 256 possible SA s. One half of these are pre-assigned. Part of SAE J1939 Network Management addresses and reacts to address conflicts. AUTOSAR 3 does not support this functionality, adding system risk if address conflicts exist. 16

17 Large Message Transmission SAE J1939 has developed a Transport Protocol to transfer long messages: Broadcast Announce Message (BAM) No Flow Control RTS/CTS With Flow Control AUTOSAR 3 does not support the Transport Protocol feature as defined by SAE J1939, limiting the system s functionality. 17

18 Diagnostics SAE J1939 has a diagnostic protocol that implements DiagnosticMessages (DM). There are currently a total of 52 defined DMs and contain: DMs for legislated (OBD) communication DMs for enhanced diagnostics Support of a minimum set of SAE J1939 DMs is critical to Heavy Duty Vehicle adoption of AUTOSAR, especially in markets using SAE J1939 OBD communication. AUTOSAR 3 does not support SAE J1939 DMs, limiting its use in North America. 18

19 The Solution: AUTOSAR Several Heavy Vehicle manufacturers petitioned the AUTOSAR Consortium to add a number of SAE J1939 support features to overcome the issues just described Earlier this year, the consortium agreed to this request. Since that time, these Heavy Vehicle OEMs (and others) have been working with Vector to review the documentation that Vector has been developing. AUTOSAR is due the end of Q

20 The Solution: AUTOSAR The following J1939 features satisfy the initial SAE J1939 requirements: Feature-ID Title Extended PDUs: Variable Frame IDs in System Description J1939 Network Mgmnt: Add Claiming and Startup Behavior J1939 Request Management J1939 Diagnostics with Access to DEM J1939 OBD 20 DM messages implemented 20

21 Conclusion AUTOSAR contains 5 SAE J1939 features. These new AUTOSAR features provide enough additional SAE J1939 functionality to make it an attractive option for a larger share of the Heavy Duty Vehicle market. Thank you for your time and attention! 21

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