Research on Rail Pressure Control of High-Pressure Common Rail System for Marine Diesel Engine Based on Controlled Object Model

Abstract

The common rail pressure of a marine diesel engine high-pressure common rail system is typically controlled by a PID (Proportional Integral Differential) algorithm, which has problems with both overshoot and response delay. In this paper, the control method based on controlled object model for rail pressure is studied. The control model for a high-pressure common rail system is established within the controller. Through the developed control model and the current actual rail pressure obtained by real-time acquisition, the control variables issued by the controller to the controlled object are predicted and calculated. The fuel supply required in the whole high-pressure common rail system is calculated in advance, with the fuel supply then taken as the input value for the driving model in order to calculate the PWM control signal required by the high-pressure oil pump. A PWM control signal is used to control the proportional valve opening of the high-pressure oil pump, and then control the fuel pressure in the common rail pipe. In order to verify the correctness and control effects of the rail pressure control strategy based on controlled object model, a real-time simulation of the high-pressure common rail system has been developed by combining calculation equations with a MAP data query, which ensures real-time performance. At the same time, the real-time simulation of the high-pressure common rail system shows that the error between the simulation's calculation and the actual test data is less than 5%, and thus model accuracy is guaranteed. The control method based on controlled object model is combined with the realtime simulation model for the high-pressure common rail system to verify the control strategy function, and the control effect is then compared with that of the PID control. Comprehensive verification shows that the control strategy based on controlled object model can significantly improve the response delay and overshoot of PID control. INDEX TERMS Marine diesel engines, Model-based control, High-pressure common rail systemThis work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.

Matching analysis on flow limiting valve of marine diesel engine common rail system

“…At present, CRS has been widely used in modern marine diesel engine to improve combustion efficiency, reduce harmful gas emissions and optimize overall performance [4,5] . It is necessary to configure flow limiting valves on the common rail pipe to realize the over flowing protection of high pressure circuit of the CRS, so as to meet the extremely high requirements of working stability and reliability of the CRS for marine generator set diesel engine [6][7][8] .…”

Research on fuel injection characteristics of common rail system based on high pressure pipeline integration and matching

“…This is affected by common rail pressure control which is generally based on the optimization control of electronic control unit (ECU). [8][9][10][11] HPCRS are studied in the order from fuel supply module to accumulator module and then to fuel injection module based on the fuel running route. Su et al 12 carried out a three-dimensional hydrodynamics simulation calculation on the oil supply pipeline of HPRCS, and studied the relationship between the pressure fluctuation in the pipeline and the flow rate fluctuation.…”

“…The fuel flow characteristics of injectors measure the performance of HPCRS. This is affected by common rail pressure control which is generally based on the optimization control of electronic control unit (ECU) 8–11 …”