New Air Control Logics for HD Diesel Engines for Most Stringent Emission Demands and Best Customer Value in Terms of Fuel Consumption and Engine Response

The upcoming worldwide legislations for emission reduction demand a significant further reduction of Diesel engine tailpipe emissions for all various applications. Also the introduction of new test procedures for On-Road (WHTC – World Harmonized Transient Cycle) as well as Off-Road (NRTC – Non Road Transient Cycle) increases the challenge for compliance due to higher dynamic or transient requirements. As function of the anticipated vehicle installation and the exact legal boundaries a further strong decrease of engine-out emissions is necessary, despite the widespread use of efficient exhaust aftertreatment systems. The parallel minimization of PM and NOx engine-out emissions requests for the majority of engines significant technology upgrade in terms of FIE (Fuel Injection Equipment), EGR (Exhaust Gas Recirculation), turbocharger systems and coolers. All improvements result in a significantly lowered level of steady-state emissions over the engine map. The application of all these highly efficient technologies will result in a very complex design if a significant emission improvement on one side and robust comfortable and spontaneous engine response under all real world operating conditions on the other side have to be attained. All control functions must remain transparent to the vehicle operator, e.g. the transition between different operating modes for various purposes (normal mode, heating mode, regeneration mode, etc.). This paper provides details about the most important characteristics and results of advanced control logic for the next generation of Diesel engine applications. As an evolutionary step, the so-called ‘emission index controller’ will be described. This emission index controller provides advanced capabilities to decrease transient engine-out emissions. Also scattering and long term durability effects can be covered with such an advanced algorithm. In a second step, detailed application results from actual developments with this controller strategy will be shown in conjunction with an outlook for further developments.