Improving Calibration Quality by Virtual Testing Approach for BS VI Emission Norms

BS-VI or equivalent development calls for tremendous efforts in concept investigation and calibration for engine out, after treatment, diagnostic checks, off-cycle emissions, field performance, component safety etc. Achieving calibration quality for all these tasks is very challenging considering development time and cost with conventional physical testing approach. Present article focuses on assessment of testing and calibration using virtual approach. To prove and validate this approach, a six-cylinder heavy duty diesel engine is selected and configured in HiL environment. The engine plant model is built offline and validated with base engine data at steady state and transient operations and RT model is integrated with ECU hardware. Data for plant model corrections is generated with short measurement campaign. Refined real time plant model is prepared for evaluating different calibration strategies on virtual test bed environment. It is observed that, performance and emission predictions portray an accuracy of the order of 90%. This approach has benefited to a great extent in reduction of calibration efforts, ease of calibration for nonstandard ambient conditions, screening of various hardware options, fast calibration of engine derivatives for various applications and without any change in the calibration toolchain platform. Virtual calibration methodology has displayed huge potential to handle complexity and efforts in calibration desired for upcoming real driving emission norms.