Switching Fractional-Order Controllers of Common Rail Pressure in Compressed Natural Gas Engines

A dynamical model of electro-injectors for common rail diesel engines

“…electroinjectors, must be sufficiently accurate and fast at the same time [1], [2], [3], [4]: the precision of fuel metering guarantees the injection of the proper amount in the combustion chamber; the metering speed allows the modulation of fuel rate (the so-called Injection Rate Shaping) by means of successive multiple injections [5], [6]. The optimization of the injection system and the design of injection control can benefit from the availability of suitable dynamic models [7], [8], [9], [10]. However, an electro-injector is a complex system, characterized by non-linear phenomena and parametric variations (due to variations of electro-mechanical parameters with working conditions) [6], [11], [12], which affect system performance if an accurate control of fuel metering is needed.…”

Parameter estimation in non-linear models of pressure dynamics in CNG injection systems

“…On the other hand, the challenge is to achieve robust and effective regulation of the common-rail pressure. This last issue is due to the gas intrinsic compressibility that makes it difficult the adaptation to distinct working points, as determined by the driver's requests of power and speed variations, or to other parametric variations and the rejection of load disturbances [1], [2], [3], [4]. Accurate models of the injection system can be used to diagnose faults, to explore different configurations, and to test different geometrical and functional designs.…”