Design and experimental validation of a model-based rail pressure controller for common rail diesel engines

The high pressure common rail (HPCR) fuel injection systems are widely used in modern diesel engines. The control of the rail pressure becomes challenging in transient process over the whole range of operating conditions. To effectively address this issue, a model-based rail pressure controller (RPC) in the HPCR fuel injection system for diesel engines is proposed based on the dynamic feedforward control algorithm, the static feedforward control algorithm and the observation feedback control algorithm. The dynamic feedforward control algorithm for the rail pressure is designed based on the mathematical model. The static feedforward control algorithm for the rail pressure is designed based on the look-up tables (curves and maps). The observation feedback control algorithm for the rail pressure is designed based on the linear active disturbance rejection control (LADRC). The RPC is simulated and implemented in the ASCET software environment of ETAS GmbH and has been integrated to an in-house developed electronic control unit (ECU) of HPCR diesel engines. Experimental validation of RPC has been conducted on a turbocharged V-8 HPCR diesel engine test bench. Experimental results are provided to confirm the effectiveness of the proposed controller. From the experimental results, it is observed that the RPC shows a good degree of tracking performance in a wide range of the engine operating conditions.