GB Tech helps Saft mitigate multiple risk factors on Department of Defense Joint Strike Fighter

Challenge

DOD determined that an existing commercial Lithium Ion (Li-ion) Battery Management System was of value in the austere military avionics environment for the DOD’s JSF program.

Overcharge prevention is the paramount reason for having cell-level monitoring capability within a Li-Ion battery. The software system for the JSF Battery Pack was designed to monitor every cell and many temperatures within a battery to ensure continued safe operation and maximum performance over the life of the battery.

GB Tech was assigned the task of IV&V and testing the JSF 28-Volt CANProbe© software for Saft America, Inc., a direct subcontractor to Smiths Aerospace, the Power Subsystem contractor for the Lockheed Martin Joint Strike Fighter project.

Solution

GB Tech provided support in the production of requirements and design documentation, as well as independent software testing and IV&V.

The work was done independent of the development organization per the requirements of Lockheed Martin’s Joint Strike Fighter ((JSF) Software Development Plan for Safety Evidence Assurance Level (SEAL) 2, for items relating to a hazard risk index of 4–7 on a scale of 1–20. SEAL 2 required performance of Failure Modes and Effects (FMEA) testing. An actual hardware error was simulated in each subsystem to check the ability of the software to handle each failure condition without compromising its’ primary battery safeguard mission.

Result

Upon completion of the IV&V effort, GB Tech made more than 200 code improvement recommendations. A major problem was discovered which required a new software version release and a complete retesting regiment because the battery was unable to recharge. Another problem in integration testing showed that the system exceeded the stated CPU utilization requirements.

Because GB Tech found these issues, Saft was able to make improvements prior to incorporation into the JSF. GB Tech helped Saft mitigate multiple risk factors with the Li-on Battery Management System and dramatically lowered the cost of fixing the problems, keeping in line with the DOD’s mission of affordability for the Joint Strike Fighter program.