Control strategy for electronic fuel injection system for a low-power non-road diesel engine

XI Zhideng; HU Shiji; MA Zhihao; ZENG Ke

doi:10.19471/j.cnki.1673-6397.2025.02.002

Abstract：To develop a diesel engine electronic control system with fully independent intellectual property rights that meets current emission standards,and to achieve complete domestication of the high-pressure common rail diesel engine control system,a control strategy for the electronic fuel injection system of small power non-road National Ⅳ high-pressure common rail diesel engines is developed and optimized based on domestic chips.In the fuel injection module,the basic fuel injection amount is determined based on the engine speed and internal required torque,and the injection combinations,pulse width,and fuel injection timing for multiple injections are obtained based on the injector controller.The speed control module maintains the engine speed within the high and low idle ranges by using control methods for upper and lower limits of high and low idle speeds and employs an active surge damping control strategy to suppress engine speed fluctuations.The rail pressure control module combines feedforward control with a dual proportional-integral-derivative(PID)closed-loop control strategy.The control program is downloaded to the independently developed electronic control unit,and bench tests are conducted on a 4-cylinder high-pressure common rail diesel engine.The test results show that the designed control strategy can meet the control requirements for non-road diesel engines with a power output not exceeding 37 kW.After applying this strategy,the engine can successfully start within 2.2 s and smoothly operates from the starting state to the idle state.Under various operating conditions,the fluctuations in the engine's rail pressure and speed are relatively small,during sudden changes in external load,the engine speed can recover to the target speed within a short period and stabilize.The specific emissions of all pollutants comply with the National Ⅳ emission standard requirements.