HARDWARE – IN – LOOP TEST BENCH DEVELOPMENT AND AUTOMATION FOR FAILURE MODE EFFECTS TEST OF AFTER-TREATMENT SYSTEM 1

After-treatment system uses urea to treat exhaust gases coming out of automotive vehicles in order to meet the automotive emission regulation, on board diagnostics and to make environment cleaner and safer. A dosing unit called Doser is used to inject the Urea. This system is electronically controlled through an ECU based on inputs & outputs from set of sensors &actuators inside the doser. In order to assess the performance of this control system, circuit continuity and its functions Failure Mode Effect Tests (FMET) are conducted. In the conventional FMET system the tests are simulated and its functionality is assessed by using the normal bench which consists of ECU, Doser and wiring harness. However, a new test bench set up called as Hardware – in – loop test bench can be developed and automated with NI test stand. The hardware in in loop test bench consists of ECU, Load box User Interface System (LUIS), Wiring Harness, FMET box and Doser. This test bench can be used in order to increase the accuracy and to reduce the test time. KeywordsAfter-Treatment, Doser, Hardware-in-loop Testing, LUIS and Test Automation.