小功率非道路柴油机电控喷油系统控制策略

习志等¹，胡世纪¹，马志豪^1*，曾科²

1. 河南科技大学车辆与交通工程学院，河南 洛阳  471003；

2. 西安交通大学能源与动力工程学院，陕西 西安  710000

摘要：为开发具有完全自主知识产权并满足现行排放标准要求的柴油机电控系统，实现高压共轨柴油机控制系统的完全国产化，基于国产芯片开发并优化小功率非道路国四高压共轨柴油机电控喷油系统控制策略。燃油喷射模块依据发动机转速和内部需求转矩得到基本喷油量，并根据喷射控制器得到多次喷射的喷射组合、脉宽以及喷油正时；调速模块通过设置高、低怠速限值将发动机转速控制在目标怠速区间内，并采用主动阻尼控制策略抑制发动机转速波动；轨压控制模块采用前馈和双比例积分微分（proportional integral derivative，PID）闭环控制相结合的控制策略；将控制程序下载到自主开发的电子控制单元中，并在1台4缸高压共轨柴油机上进行台架试验。试验结果表明：设计的控制策略能够满足功率不超过37 kW的非道路用柴油机的控制需求；发动机在2.2 s内顺利起动，并从起动状态平稳运行至怠速状态；各工况下，发动机轨压和转速波动较小；外界负荷突变过程中，发动机转速能够在较短时间内恢复至目标转速并稳定；各污染物的比排放均满足非道路柴油机国四排放标准要求。

关键词：高压共轨；喷油系统；控制策略；台架试验；PID闭环控制

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

XI Zhideng¹, HU Shiji¹, MA Zhihao^1*, ZENG Ke²

1. College of Vehicles and Traffic Engineering, Henan University of Science and Technology, Luoyang 471003, China;

2. School of Energy and Power Engineering, Xi′an Jiaotong University, Xi′an 710000, China

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.

Keywords: high-pressure common rail; fuel injection system; control strategy; bench test; PID closed-loop control