Evaluating Influence of On-Road Parameter Variation in HD Application Using Virtual Approach for Upcoming IRDE Norms

Real Driving Emission (RDE) norms have changed the way vehicles are required to be calibrated and developed. This has moved the legislative requirements from predictable lab conditions to more realistic, real world conditions. Current Indian legislation allows certification for Heavy Duty (HD) applications on engine level and therefore decoupled from vehicle and the real world scenarios such as uncertainty and randomness in driver behavior, traffic conditions, road profiles, ambient conditions etc. which are not captured. Upcoming RDE legislation to be implemented in year 2023, has made it necessary to integrate engine with vehicle to consider the impact of various parameters on engine operating points and therefore on tail pipe emissions. This paper focusses upon the methodology developed using RDE cycle generator tool (RCG) for generating on-road parameters which influences the zone of engine operation and resulting emission levels. At ARAI, we have established a calibration strategy for Heavy Duty Commercial Vehicles for BS-VI RDE using virtual technique, which can be easily extendable to passenger vehicles as well. Virtual Test Bed (VTB) approach gives advantage to include all possible variations during early stages of vehicle calibration and therefore making it more robust. RDE Cycle Generator (RCG) module from AVL is used to generate GPS based road profile data including gradients and realistic traffic conditions. The module is capable to consider Indian legislative requirements for HD application requirements. The well validated Real Time (RT) HD vehicle plant model capable of complying to BS-VI norms is considered for evaluating influence of different parameters. Different routes are generated by varying parameters such as driver characteristics, traffic conditions, start and stop criteria etc. The vehicle is operated virtually under all possible extreme conditions to evaluate the engine-operating zone and accordingly revisit the calibration requirements to avoid surprises during real vehicle testing. The convenience of changing any critical parameter on RCG and then running vehicle virtually on VTB has benefitted in reducing the time and efforts for calibration and focusing more on calibration work and thus will help in achieving In-Service Conformity (ISC) requirements more confidently.