Cylinder Pressure-Based Closed Loop Combustion Control: A Valid Support to Fulfill Current and Future Requirements of Diesel Powertrain Systems 2015-24-2423

The strategies adopted to control the combustion in Diesel applications play a key role when dealing with current and future requirements of automotive market for Diesel powertrain systems. The traditional “open loop” control approach aims to achieve a desired combustion behaviour by indirect manipulation of the system boundary conditions (e.g. fresh air mass, fuel injection). On the contrary, the direct measurement of the combustion process, e.g. by means of in-cylinder pressure sensor, offers the possibility to achieve the same target “quasi” automatically all over the vehicle lifetime in widely different operating conditions.

Beside the traditional combustion control in closed loop (i.e. based on inner torque and/or combustion timing), the exploitation of in-cylinder pressure signal offers a variety of possible further applications, e.g. smart detection of Diesel fuel quality variation, control of combustion noise, modeling engine exhaust emission (e.g. NO_x). Such advanced cylinder pressure-based control concepts can support the development of Diesel powertrain systems, taking into account recent trends characterized by an increasing system complexity, additional degrees of freedom related to e.g. real world driving emissions (RDE) procedure or penetration of opening markets, as well as an increasing attention paid by modern OEMs towards the development efficiency (time/costs optimization).

In this contribution an overview about the on-going development activities is given and the deriving benefits are illustrated with the support of experimental results.