Disclaimer: This engagement had put to test, our team’s capability in achieving ASIL-C compliance of the Complex Device Drivers for an AUTOSAR based Powertrain control unit.
We have a long-standing and a successful partnership with this India based OEM, pioneering in Electric Vehicles.
During our previous engagements, our automotive product engineering team had developed Complex Device Drivers (CDD) for the customer. These device drivers were necessary to extend the functionalities of a pre-designed AUTOSAR based powertrain ECU.
Some new hardware components in the powertrain ECU like speed sensors, and Real Time Clock (RTC), I/O expander, H-Bridge etc. had to be added. Due to speed constraints and few other limitations, these components had to be kept separate. Therefore complex device drivers were required for the communication between powertrain ECU and additional hardware components.
Also having develop confidence in our Automotive Functional Safety capabilities, the customer inked an additional responsibility and entrusted us with ISO26262 based ASIL-C compliance of the CDDs.
The complex device drivers were already developed and are ready-to-be deployed. Customer realized the need for ASIL-C compliance of these device drivers post the development.
This realization was the result of the HARA analysis (as per ISO26262 framework) performed by the customer at a later stage. The components with which CDD interacted were mostly ASIL-C. It was therefore decided that these device drivers should also be ASIL-C compliant.
The main challenge before the customer was to go back to the design level and implement ISO26262 mandated safety planning activities across the development process.
After a few rounds of discussion with the functional safety team of the customer, the following project scope was chalked out:
As the complex device drivers were already developed, we had to retrace our steps and go back to the unit designing part. We covered part-2, part-6 and part-8 of the safety lifecycle as recommended by ISO26262 standard.
Here is the step-by-step process we adhered to for ISO26262 ASIL-C compliance safety lifecycle–
The Unit Design, Implementation and Testing was implemented as per the mandatory guidelines for ASIL-C compliance under Part-6 document of the ISO26262 standard.
This is how our team structure looked like:
Team comprised of a dedicated Safety Manager along with a Project Manager. The Functional Safety team, Software Development team and the QA team worked together to ensure all the guidelines of ISO26262 standard were implemented in letter and spirit.
We were able to make a considerable impact with our Functional safety expertise. The production-grade Complex Device Drivers were now on the same level as the components they interacted with i.e. ASIL-C.
The impact was felt across all components that communicated with the help of CDDs:
Better measurement of the fault would also help in prevention of any damage in the future. In the context of electric vehicles this would help the customer in the long run to build safer and more efficient EVs.
As we had developed the CDDs for the customer, our automotive team was fully aware of the project nuances. This reduced the time and cost to get the ASIL-C compliance done.