基于模型的车用柴油机轨压控制器设计及试验验证

Design and Experimental Validation of a Model-Based Common Rail Pressure Controller for On-Road Diesel Engines

针对现代车用柴油机高压共轨燃油系统在全工况范围内连续瞬态过程的轨压控制问题,提出了一种基于模型的轨压控制器.通过对高压共轨燃油系统轨压变化基本原理的分析,设计了一种基于模型的轨压前馈控制算法,并基于发动机转速和轨压偏差设计了轨压分段PID反馈控制算法.利用ETAS公司ASCET软件实现了该轨压控制器,在与自主高压共轨柴油机ECU进行集成后,开展了发动机台架和整车道路试验.试验结果表明:该轨压控制器在稳态过程可将轨压控制在±1.5,MPa波动范围之内,在连续瞬态过程可将轨压控制在±3.5,MPa波动范围之内,具备快速响应性、动态跟踪、高稳定性和高可靠性功能,满足全工况范围内轨压控制要求,为工程实际用轨压控制器设计奠定了基础.

A model-based common rail pressure controller（CRPC） was proposed to achieve common rail pressure control in transient process over the whole range of operating conditions for high pressure common rail（HPCR）fuel injection systems（FIS）in modern on-road diesel engines. A model-based rail pressure feed-forward control algorithm was put forward based on analysis of the fundamental principle of rail pressure changes in the high pressure common rail fuel injection system,and a piecewise PID feedback controller was designed based on the engine speed and the deviation of common rail pressure. The proposed CRPC was simulated in the ASCET software environment of ETAS Gmb H and implemented in the homemade electronic control unit（ECU）of HPCR diesel engines. Experimental validation of CRPC was conducted on an HPCR diesel engine test bench and an on-road heavy-duty diesel truck. Experimental results show that the proposed CRPC,which can control the rail pressure within ±1.5,MPa under steady state conditions and ±3.5,MPa under transient conditions,has rapid response,good dynamic tracking behavior,high stability and high reliability. The proposed CRPC can meet the defined requirement for the control of common rail pressure over the whole range of operating conditions and lays a good foundation for further engineering application.