缸内直喷汽油机的自抗扰轨压跟踪控制器设计

获得期望的共轨压力是保证缸内直喷发动机(GDI)稳定工作和喷油量精确控制的一个重要前提. 本文针对缸内直喷汽油发动机轨压控制问题, 首先通过动力学分析建立了共轨燃油喷射系统的数学模型; 由于系统中存在有较强的非线性和不确定性, 采用基于模型但对模型的精确形式依赖较小的自抗扰控制技术设计轨压跟踪控制器,其中线性扩张状态观测器(ESO) 对系统存在的总扰动和不确定性进行了估计, 非线性误差反馈控制(NLSEF) 则采用反馈补偿实现扰动的抑制. 最后, 通过给定不同的参考轨压对控制器的有效性进行验证, 仿真结果表明控制性能是满意的.     

Introduction to the benchmark challenge on common rail pressure control of gasoline direct injection engines

As one of the most important actuators for gasoline direct injection technology, common rail systems provide the requested rail pressure for fuel injection. Special system characteristics, such as coupled discrete-continuous dynamic in the common rail system, limited measurable states, and time-varying engine operating conditions, impel the combination of advanced methods to obtain the desired injection pressure. Therefore, reducing the pressure fluctuation and satisfying engineering implementation have become noteworthy issues for rail pressure control (RPC) systems. In this study, the benchmark problem and the design specification of RPC proposed by 2018 IFAC E-CoSM Committee are introduced. Moreover, a common rail system model is provided to the challengers, and a traditional PI control is applied to show the problem behaviors. Finally, intermediate results of the challengers are summarized briefly.     

Terminal sliding mode control of rail pressure for gasoline direct injection engines

The desired fuel rail pressure is a crucial factor for guaranteeing the gasoline direct injection (GDI) engine to work stably. In order to solve the rail pressure control problem, the detailed nonlinear model of GDI is derived and reasonable simplification of this model is carried out for the following controller design. Terminal sliding mode control strategy is proposed to design the rail pressure controller with Lyapunov stability. The designed approach with the fast terminal sliding mode surface makes the system have the capacity of global fast convergence and achieves precise tracking control. To demonstrate the validity of the designed control method, simulations are conducted by tracking the different reference rail pressures. Results show that the designed controller tracks the given reference accurately and has strong robustness.     

柴油机共轨压力模糊自适应PID控制研究

柴油机高压共轨燃油系统中,共轨压力决定了燃油喷射压力,共轨压力随不同工况的调节能力及其压力的稳定性从根本上影响着系统性能。针对共轨压力控制,设计了模糊PID控制器,增加了积分分离与轨压预控制技术,给出了共轨压力的控制策略和实现方法。通过对PID参数的在线自适应整定,实现了在不同柴油机工况下对不同共轨压力变化的最佳控制。台架实验结果表明,共轨压力随柴油机转速与单次喷油量的增加应相应提高;当柴油机转速较高时,PID控制器应采用较大的控制参数;轨压预控制可有效地减少轨压波动和缩短轨压稳定时间;提出的控制策略和实现方法可把轨压控制偏差稳定在1.7%以下。     

Rail pressure controller design of GDI basing on predictive functional control

Gasoline direct injection (GDI) is a pivotal technique for a highly efficient engine. However, how to maintain a stable rail pressure which offers good fuel economy and low emissions, is still a challengeable work. In this paper, a rail pressure controller is designed basing on predictive functional control (PFC), a model predictive control (MPC) method, to surmount the nonlinearity and discontinuity brought by the common rail pressure system (CRPS). A control-oriented piecewise linear model is presented to simplify the CRPS. The simulation results on a benchmark show that rail pressure tracks the setpoint accurately even with some perturbations. Profiting from the conciseness of PFC algorithm, the controller can compute the online solution in a short time, which makes it possible to realize the strategy on a fast response system.     

柴油机喷油过程的计算机测试

介绍了柴油机中同过程计算机测试系统的原理，设计和影响测试精度的因素，给出了实现测试结果，测试参数包括喷油压力，喷油速率，循环油量，喷油持续角，针阈升程等喷油过程主要特征参数。该系统能方便可靠地测试单次或多次平均的喷油过程参数，其测试结果可用以分析柴油机的燃烧过程和性能，改进供油系统，检验喷油过程的数学模型等。     

Optimal combustion control with application to engine design and development

The need to reduce development time whilst simultaneously improving engine performance has motivated this application of optimal control to product development processes for engines and powertrains. The optimisation of the fuel consumption is formulated as a constrained Optimal Control Problem (OCP) and solved using pseudospectral methods, giving the optimum heat release and injection profiles in the presence of cylinder pressure rate and cylinder pressure constraints. The technique is applied to an engine design problem and used to reduce fuel consumption by optimising compression ratio within a cylinder pressure limit, also providing new insights into the combustion processes.     

一种基于多次喷射的高压共轨喷油控制算法

设计了一种应用于柴油机高压共轨系统的喷油控制算法.该算法针对现有的多次喷射技术进行了改进,细化了喷油次数以提高燃油燃烧效率,采用并发控制方式提高算法执行速度.该算法首先通过基于优先级和区段划分的多次喷射协调方法将喷油过程划分为5次独立的喷射过程,然后分别对每次喷射进行油量计算、分解、正时转换等控制计算,其中分解运算过程采用了并发控制算法以提高运算效率,最终将喷油量转换为脉冲序列以操作喷油器喷油.通过理论分析与仿真实验对该算法的功能和性能进行了验证.     

Simple adaptive air-fuel ratio control of a port injection SI engine with a cylinder pressure sensor

The problem of air-fuel ratio(AFR) control of the port injection spark ignition(SI) engine is still of considerable importance because of stringent demands on emission control. In this paper, the static AFR calculation model based on in-cylinder pressure data and on the adaptive AFR control strategy is presented. The model utilises the intake manifold pressure, engine speed, total heat release, and the rapid burn angle, as input variables for the AFR computation. The combustion parameters, total heat release,and rapid burn angle, are calculated from in-cylinder pressure data. This proposed AFR model can be applied to the virtual lambda sensor for the feedback control system. In practical applications, simple adaptive control(SAC) is applied in conjunction with the AFR model for port-injected fuel control. The experimental results show that the proposed model can estimate the AFR, and the accuracy of the estimated value is applicable to the feedback control system. Additionally, the adaptive controller with the AFR model can be applied to regulate the AFR of the port injection SI engine.     

Revisiting the benchmark problem of starting control of combustion engines

Starting of combustion engines is a typical transient operating mode that has significant influence to the engine performance. Due to the distinct variations in the pathes of air intake and fuel injection, the model of the engine system contains considerable uncertain parameters. To search effective control schemes that guarantee desired performance, engine starting control is proposed as a benchmark challenge problem. As a challenging result, a model-based control scheme is developed perviously. In this work, the benchmark problem is revisited and a modification for the fuel injection path control of the previous work is proposed by integrating a time sequence regressive based parameter tuning strategy. Validation by the benchmark problem simulator shows that although the new strategy has simple structure, similar control performance is obtained. Especially, the new strategy has potential extensibility with learning based methods to further improve the performance of the benchmark problem on engine starting control.     

车用汽油发动机电子控制系统研究现状与展望

发动机电子控制系统是高性能、高可靠性发动机开发的核心研究内容,是保证发动机动力性、经济性和排放性的重要因素之一.针对车用汽油发动机,本文首先分析了典型的车用汽油发动机电子控制系统结构,然后围绕电子节气门控制系统、燃油喷射控制系统、点火控制系统、空燃比控制系统、怠速控制系统、涡轮增压控制系统、爆震检测与控制系统以及汽油机先进燃烧模式控制这8项关键问题展开论述,并着重介绍了近年来国内外的研究内容和研究成果.最后对车用汽油发动机电子控制系统的发展前景和发展方向进行了展望.     

基于小波变换的柴油机故障智能检测新方法

提出了一种智能检测柴油机喷油压力信号特征点的新方法,可以对柴油机一些常见故障进行不停机的检测。通过对油压信号特征的分析,对之进行了连续小波变换,根据油压信号在不同阶段的频率特征选定相应尺度的小波系数,然后利用这些小波系数的模极小值进行特征点的检测。将现场实测信号在Madab中进行仿真,建立了喷油系统正常工作时的模板向量。实验证明该方法的准确率高,而且便于在各种数字信号处理终端中实现,是有效可行的。     

Hybrid modelling and control of the common rail injection system

We present an industrial case study in automotive control of significant complexity: the new common-rail fuel-injection system for Diesel engines under development at Magneti Marelli Powertrain. In this system, an inlet metering valve, inserted before the high pressure (HP) pump, regulates the fuel flow that supplies the common rail according to the engine operating point (e.g., engine speed and desired torque). The standard approach in automotive control based on a mean-value model for the plant does not provide a satisfactory solution as the discrete-continuous interactions in the fuel injection system, due to the slow time-varying frequency of the HP pump cycles and the fast sampling frequency of sensing and actuation, play a fundamental role. We present a design approach based on a hybrid model of the Magneti Marelli Powertrain common-rail fuel-injection system for four-cylinder multi-jet engines and a hybrid approach to the design of a rail pressure controller. The hybrid controller performs significantly better when compared with the classical mean-value based approach.     

L195柴油机改装燃用酒精试验分析

本文是通过两年的科研实践,就L195柴油机改装燃烧低纯度酒精的可行性、影响性能因素等有关问题进行了分析。重点放在气流的涡流强度、酒精的喷射压力、油束雾化、火源位置以及喷油、点火正时的配合。文章最后肯定了酒精作为代用燃料是比较理想的一种代用燃料,柴油机改装燃用酒精发动机是有前途的。     

MC33810在四缸汽油机喷油与点火系统中的应用

介绍了MC33810的内部结构原理,以Freescale公司的MPC564作为ECU,设计了ECU的供电电路、最小系统电路和ECU与MC33810在四缸汽油机中的喷油及点火控制电路,并根据该电路设计了具体喷油和点火的软件程序流程。该喷油与点火系统电路具有结构简单、驱动方式灵活、驱动电路稳定和使用寿命长的特点。     

基于MC9S12的电控燃料喷射系统研究

利用单片机MC9S12,在单缸柴油机基础上设计乙醇/柴油双燃料发动机电控燃料喷射系统.分析了系统组成及功能,设计系统硬件电路,利用单片机输入捕捉输出比较时序控制、燃料喷射脉宽脉谱和双线性插值查表算法实现对乙醇燃料喷射量的精确控制.仿真及试验测试表明,利用该系统可实现不同工况下乙醇燃料变脉宽喷射,有效地进行乙醇/柴油混合...     

基于单片机的双燃料汽化器微机控制系统设计

汽油发动机双燃料汽化器采用乙醇和汽油分开放置的燃料储存方式,避免了乙醇汽油存在的诸多弊端,在此,设计了以AT89S52单片机为核心的双燃料汽化器的微机控制系统,该控制系统实现了双燃料汽化器的按键显示、缺液检测及报警、发动机转速测量及计算、乙醇泵堵转检测及保护、乙醇量喷射控制、液压缸液压杆限位检测及保护等功能,同时,能实时采集汽车发动机的转速信号,通过预置的软件对发动机转速进行分析,精确计算出乙醇单次喷射时间和喷射频率,从而准确控制乙醇与空气、汽油的按配比混合掺烧,提高了汽油的燃烧效率,降低了油耗,减少了有害物质的排放,达到了节能减排的目的;实际应用中,该控制系统运行稳定,抗干扰性能良好,控制准确,具有一定的实际应用价值。     

Control of the common rail pressure in gasoline engines through an extended state observer based MPC

In this paper, a model predictive control (MPC) solution, assisted by extended state observer (ESO), is proposed for the common rail pressure control in gasoline engines. The rail pressure dynamic, nonlinear with large uncertainty, is modeled as a simple first order system. The discrepancy of the model from the real plant is lumped as ``total disturbance'', to be estimated in real-time by ESO and then mitigated in the nonlinear MPC, assuming the total disturbance does not change in the prediction horizon. The nonlinear MPC problem is solved using the Newton/generalized minimum residual (GMRES) algorithm. The proposed ESO-MPC solution, is compared with the conventional proportional-integral-differential (PID) controller, based on the high-fidelity model provided in the benchmark problem in IFAC-E-CoSM. Results show the following benefits from using ESO-MPC relative to PID (benchmark): 1) the disturbance rejection capability to fuel inject pulse step is improved by 12% in terms of recovery time; 2) the transient response of rail pressure is improved by 5% in terms of the integrated absolute tracking error; and 3) the robustness is improved without need for gain scheduling, which is required in PID. Additionally, increasing the bandwidth of ESO allows reducing the complexity of the model implemented in MPC, while maintaining the disturbance rejection performance at the cost of high noise-sensitivity. Therefore, the ESO-MPC combination offers a simpler and more practical solution for common rail pressure control, relative to the standard MPC, which is consistent with the findings in simulation.     

Model predictive control of HCCI using variable valve actuation and fuel injection

Control of work output and combustion phasing on a Homogeneous Charge Compression Ignition (HCCI) engine is essential to realize the benefits of superior efficiency and emissions. This paper presents a model predictive control approach for cycle-by-cycle control of HCCI while respecting constraints on actuators that might exist on a production implementation. The strategy is based on a physical model developed in previous work and uses valve actuation and split fuel injection to achieve the control objectives. In addition, it considers constraints on air-fuel ratio, ensuring that the system stays away from very lean or rich regions. Simulation and experimental results show that the controller works well over a range of conditions, and demonstrate the potential of this approach as a practical cycle-by-cycle control strategy for HCCI.     

Model-based cold-start speed control scheme for spark ignition engines

This paper presents a model-based control scheme to the cold-start speed control in spark ignition (SI) engines. The multi-variable control algorithm is developed with the purpose of improving the transient performance of the starting engine speed: the control inputs are the fuel injection, the throttle and the spark advance (SA), while the engine speed and the air mass flow rate are the measured signals. The fuel injection is performed with a dual sampling rate system: the cycle-based fuel injection command is individually adjusted for each cylinder by using a TDC (top dead center)-based air charge estimation. The desired performance for speed regulation is achieved by using a coordinated control of SA and throttle operation. The speed error convergence of the closed loop system is proved for simplified, second-order model with a time-delay, and the robustness with respect to parameter uncertainties is investigated. The performance and the robustness with respect to modeling uncertainties of the proposed control scheme are tested using an industrial engine simulator with six cylinders.