Integration of J1939 stack with an advanced EPS system | Automotive Tier-I Supplier

The client, a trusted and reputed Automotive Tier-I Supplier of steering and driveline components, approached our Automotive Embedded Services team to resolve a very challenging embedded software development issue.

This hurdle was a grave one-it had the potential to derail the product roadmap of their futuristic Electronic Power Steering (EPS) system.

Here is the complete success story!

Business Challenge:

Our client had successfully embarked on their journey of designing an advanced Electronic Power Steering (EPS) system for Commercial vehicles. The following critical phases of product development lifecycle were already complete:

• Hardware design based on DsPIC 30F4011 Microchip Platform
• All the necessary components and hardware modules were identified and finalized as per the design needs
• In-vehicle testing of the hardware was complete
• EMI and EMC certification-related compliance was also successfully achieved
• PCB manufacturing phase was completed

However, the customer encountered a major roadblock during software porting.Due to limited on-chip memory (RAM and ROM) of DsPIC 30F4011 platform, it became imperative for the customer to port highly-optimized embedded software to the EPS system.

Re-designing or changing the hardware platform would have impacted the bottomline of the project negatively, leading to substantial financial loss. Also, the DsPIC Microchip platform was best suited for the required EPS application, meaning that the only feasible resolution was an Optimized Embedded Software.

Embitel Solution: the re-usable and layered architecture based J1939 stack:

After several engineering workshops with the customer for understanding and analyzing the EPS system, Team Embitel was able to overcome the hurdle with the help of following solution:

• A light-weight and re-usable SAE J1939 compliant stack best suited for commercial vehicles was integrated with the system
• The entire code was optimized around J1939 stack and since the stack has layered architecture, the optimized software was successfully ported thus overcoming the memory issue

SAE J1939 – Project details:

• SAE J1939 complaint Boot Loader was also ported to facilitate Reprogramming of ECUs efficiently and securely via CAN network
• The ported J1939 stack consisted of J1939 Data Link and Transport Layer (J1939\21), Network Management layer (J1939/81), Vehicle Application Layer (J1939/71) and Vehicle Diagnostics Layer (J1939/73)
• All this ensured support for vehicle communication, reprogramming, diagnostics and fault code memory
• All the necessary device drivers were designed, developed and ported by Embitel
• The EPS being an OS-independent system (non-RTOS), a Scheduler was also ported as shown in the system architecture diagram
• Onsite support for integration of stack with client’s application and in-vehicle testing services were also extended as part of this successful engagement
• J1939 stack also ensured Enhanced Portability for the steering system (Support for 8, 16 and 32 bit Embedded Controllers)

Embitel Impact:

• Timely resolution of the software issue by designing a highly optimized and high quality code
• Integration of re-usable J1939 stack not only safe-guarded the client’s product roadmap but also ensured speed-to-market and cost savings

What is SAE J1939?

Society of Automotive Engineers (SAE) J1939 is the vehicle bus recommended practice used for communication and diagnostics among vehicle components.

SAE J1939 is used in the commercial vehicle area for communication throughout the vehicle, with the physical layer defined in ISO 11898.

Source – Wikipedia