Gain-Scheduling Integrator-Augmented Sliding-Mode Control of Common-Rail Pressure in Diesel-Dual-Fuel Engine

Abstract

Accurate common-rail pressure control is vital to good engine performance and low emission. Injection strategy of diesel-dual-fuel engine varies more greatly with speed and load than its diesel engine predecessor, and so does the common-rail pressure set point. Along with this swift set point change, other control challenges exist; they are speed-and-load variation, model uncertainty, sensor noise, actuator nonlinearity, and pressure disturbance from injection. Traditional control such as the PID was proved to be only marginally effective because of the swift set point change. We proposed integrating an integrator-augmented sliding-mode control with gain scheduling and feed-forward term. The sliding-mode control has fast action and is low sensitive to model uncertainty and disturbance. The augmented integrator ensures zero steady-state error. The gain scheduling handles the speed-and-load variation. The feed-forward term helps with the actuator nonlinearity. The proposed control system was implemented with four-cylindrical diesel-dual-fuel engines on an engine dynamometer and in a prototype pickup truck, which runs on a chassis dynamometer and in road test. The common-rail pressure was accurately regulated both during the new European driving cycle test and the set point changes test. The proposed method compared favorably with the best-tuned gain-scheduling PID controller.

Rail pressure control strategy based on pumping characteristics for the common rail fuel system

“…Researchers have carried out some current research on feedforward control. Chatlatanagulchai et al 13 reported an integrator-augmented sliding mode controller integrating with gain scheduling and feedforward term to make the CR pressure control accurately. Seungwoo et al 14 developed a feedforward-feedback control algorithm.…”

Research of Rail Pressure Characteristics of Common Rail Fuel System

“…Currently, lots of efforts are being spent on control method of high pressure CR system [6][7][8] . However, the control strategy of high pressure common rail must be established based on the characteristics of high pressure wave within high pressure common rail, the pressure wave can be smaller and more stable, to make sure the injection steadiness of fuel system.…”