高压共轨柴油机判缸策略及燃油喷射控制

利用微处理器硬件资源实现曲轴脉冲信号的倍频,提高了喷油正时控制的精度,并设计了不同相位判断模式下的相位判断算法,提高了软件执行效率。针对不同的相位判断模式设计了燃油喷射控制逻辑。试验结果表明,不同相位判断模式下ECU均能快速准确获取发动机相位,燃油喷射精度在0.2°曲轴转角范围内,曲轴转速传感器或凸轮轴相位传感器故障模式下发动机能够维持运转。     

2010款雪佛兰科鲁兹车发动机故障灯异常点亮、加速无力

正故障现象一辆2010款雪佛兰科鲁兹车,搭载LDE发动机,累计行驶里程约为15万km。该车发动机怠速运转无明显异常,但发动机故障灯长亮,且加速无力。故障诊断用故障检测仪检测,发动机控制模块(ECM)中存储有3个故障代码(图1),分别为"P0016-00曲轴位置-进气凸轮轴位置不合理""P0017-00曲轴位置-排气凸轮轴位置不合理""P0341-00进气凸轮轴位置传感器性能";     

柴油机转速传感器故障诊断及其失效“跛行”控制

研究了时间控制式电控柴油机转速信号的特点及相位关系;设计了曲轴和凸轮轴传感器失效故障的检测方法及处理算法;开发了由MC68376微处理器和可编程复杂逻辑器件组成的柴油机故障处理系统;在TCD2015V06电控单体泵柴油机上,进行了起动和正常运行时转速传感器失效的试验研究。结果表明,转速传感器出现故障时,系统可识别出相应故障,并进行逻辑切换,使发动机能正常起动和运行。     

传感器失效下的电控柴油机喷射控制分析

对电控柴油机传感器失效时的状态进行了分类,提出了相应的状态转换算法,初步分析了应急喷射控制逻辑,并在一种电控单体泵柴油机上进行了试验验证。分析得出的算法可用于传感器失效时,柴油机应急喷射控制时序的设计,以及喷射控制软件的编写。     

2014款奥迪A6C7车无法起动

<正>故障现象一辆仅行驶70 km的2014款奥迪A6 C7轿车(发动机型号为CDZ),客户反映无法起动。故障诊断接车后首先验证故障现象。接通点火开关,起动发动机,发动机无法起动,故障属实。从声音判断,起动机运转正常,发动机无着机迹象,表明该车故障不是由起动机方面的原因造成的,主要应从发动机供油、点火电路、进排气管路、控制系统及信号(曲轴位置传感器信号、凸轮轴位置传感器信号、挡位信号)、发动机机械等方面着手进行检查。     

金龙6117Y型客车停车时突然熄火故障解析

<正>故障现象一辆厦门产金龙6117Y型客车,装配玉柴6J-245-30博世高压共轨发动机,2010年出厂,已累计行驶1.2万多公里,是接送职工的上下班车。雨天行驶到某红绿灯路口停车时突然熄火,再次起动发动机,起动机运转正常,但就是不着车,遂打电话要求我们进行现场救急。故障可能原因1电源线路故障;2发动机的曲轴位置传感器、凸轮轴位置传感器均失效,无信号;3燃油系高低压油路故障。     

雪佛兰科鲁兹发动机故障灯报警

<正>故障现象:一辆2014款雪佛兰科鲁兹1.6L轿车,手动变速器,行驶里程15 000km,发动机故障灯报警。故障诊断与排除:用GDS扫描全车DTC,显示当前故障码"排气凸轮轴位置不合理"。查阅资料得知,如果发动机控制模块检测到凸轮轴与曲轴错位,并且曲轴位置传感器信号比曲轴角度的标定位置提前或滞后10°,则记忆此故障码。此时发动机进入应急状态,即随着发动机工况变     

起亚K5车发动机无法正常起动

<正>故障现象一辆起亚K5车,只有踩下加速踏板,发动机才能起动着机,且一松开加速踏板,发动机就熄火。检测分析用故障检测仪检查,读得1个当前故障代码和1个历史故障代码(图1),分别为"P0014——‘B'凸轮轴位置-正时过度提前或系统性能(1排)"和"P0017——曲轴位置-凸轮轴位置相位关系(1排/传感器B)",由此怀疑该车CVVT(连续可变气门正时)系统有故障;踩下加速踏板,起动发动机,查看发动机数据流(图2),发现CVVT系统进入失效保护状态,进气凸轮轴当前位置与设定位置一致,均为127.12°,而排气凸轮轴当前位置(-100.75°)与设定位置     

曲轴位置传感器的特性及检修技巧

<正>面对电喷发动机无法启动的故障,有的汽修人员常常束手无策,盲目换件之后仍然无济于事。事实上,很多情况是由于曲轴位置传感器(又称为发动机转速传感器)损坏引起的。曲轴位置传感器安装在曲轴前端、凸轮轴     

发动机传感器:让汽车更节能

<正>应用于发动机启停系统的曲轴和凸轮轴位置传感器能够精确监测活塞位置,对发动机喷油和点火时间进行优化,从而有效减少燃油消耗和CO_2排放。发动机传感器作为检测发动机状态的"电子眼",能有效提升发动机燃油消耗性能大陆集团推出了应用于发动机启停系统(StartStop)的曲轴和凸轮轴位置传感器,其中带方向检测的曲轴位置传感器(CPDD)具有方向检测功能、灵敏度高、抗干扰     

Development of engine control using the in-cylinder pressure signal in a high speed direct injection diesel engine

Emission regulations are becoming more stringent and remain a principal issue for vehicle manufacturers. Many engine subsystems and control technologies have been introduced to meet the demands of these regulations. For diesel engines, combustion control is one of the most effective approaches for reducing not only engine exhaust emissions but also cylinder-by-cylinder variation. However, the high cost of pressure sensors and the complex engine head design for additional equipment present difficulties for manufacturers. In this paper, cylinder pressure-based engine control logic is introduced for a multi-cylinder high speed direct injection (HSDI) diesel engine. The time for 50% of the mass fraction to be burned (MFB50) and the IMEP are valuable for determining the combustion status. These two in-cylinder quantities are measured and applied to the engine control logic. Fuel injection timing is controlled to adjust the operating MFB50 to the target MFB50 using PID control logic, and the fuel injection quantity is controlled to adjust the measured IMEP to the desired IMEP. The control logic is demonstrated at steady state and during transient conditions and is applied to an NEDC mode test.     

奥迪A6型轿车发动机集中控制系统的维修

奥迪A6型轿车的发动机为信可控制汽油直接喷射式V6发动机，其控制系统包括点火控制系统，燃油喷射控制系统，怠速控制系统及排放控制系统等，介绍了奥迪A6型轿车发动机的传感器和输出装置在车上的位置，及其控制系统的故障代码表等。     

奥迪AB型矫车发动机集电控制系统的维修

奥迪A6型轿车的发动机为集中控制汽油直接喷射式V6发动机。其控制系统包括点火控制系统、燃油喷射控制系统、怠速控制系统及排放控制系统等。介绍了奥迪A6型轿车发动机的传感器和输出装置在车上的位置，及其控制系统的故障代码表等。     

Adaptation Strategy for Exhaust Gas Recirculation and Common Rail Pressure to Improve Transient Torque Response in Diesel Engines

Fuel injection limitation algorithms are widely used to reduce particulate matter (PM) emissions under transient states in diesel engines. However, the limited injection quantity leads to a decrease in the engine torque response under transient states. To overcome this issue, this study proposes an adaptation strategy for exhaust gas recirculation (EGR) and common rail pressure combined with a fuel injection limitation algorithm. The proposed control algorithm consists of three parts: fuel injection limitation, EGR adaptation, and rail pressure adaptation. The fuel injection quantity is limited by adjusting the exhaust burned gas rate, which is predicted based on various intake air states like air mass flow and EGR mass flow. The control algorithm for EGR and rail pressure was designed to manipulate the set-points of the EGR and rail pressure when the fuel injection limitation is activated. The EGR controller decreases the EGR gas flow rate to rapidly supply fresh air under transient states. The rail pressure controller increases the rail pressure set-point to generate a well-mixed air-fuel mixture, resulting in an enhancement in engine torque under transient states. The proposed adaptation strategy was validated through engine experiments. These experiments showed that PM emissions were reduced by up to 11.2 %, and the engine torque was enhanced by 5.4 % under transient states compared to the injection limitation strategy without adaptation.     

Pressure model based coordinated control of VGT and dual-loop EGR in a diesel engine air-path system

This paper describes a pressure-model-based coordinated control method of a variable geometry turbine (VGT) and dual-loop exhaust gas recirculation (EGR) in a diesel engine air-path system. Conventionally, air fraction or burnt gas fraction states are controlled for the control of dual-loop EGR systems, but fraction control is not practical since sensors for fractions are not available on production engines. In fact, there is still great controversy over how best to select control outputs for dual-loop EGR systems. In this paper, pressure and mass flow states are chosen as control outputs without fraction states considering the availability and reliability of sensors. A coordinated controller based on the simple control-oriented model is designed with practical aspects, which is applicable for simultaneous operations of high pressure (HP) EGR, low pressure (LP) EGR, and VGT. In addition, the controller adopts the method of input-output linearization using back-stepping to solve the chronic problems of conventional pressure-based controllers such as coupling effects between operations of HP EGR, and VGT. The control performance is verified by simulation based on the proven GT-POWER model of a heavy-duty 6000cc diesel engine air-path.     

Influence of the accelerating operation mechanism on the combustion noise in DI-diesel engines

This paper focuses on the mechanisms of combustion noise during the accelerating operation of multi-cylinder diesel engines using testing technology for the transient conditions of IC engines. Based on impact factors, such as the gas dynamic load and cylinder pressure oscillations, tests and analysis of the combustion noise during transient and steady-state conditions for different loads are made on four-cylinder naturally aspirated engines, turbocharged engines, EGR-introduced engines, and high pressure common rail engines. The laws of combustion noise difference for the same engine speed and load are researched during transient and steady-state conditions. It is found that during transient conditions, the maximum pressure rise rate and the high frequency oscillation amplitude of the cylinder pressure are all higher than those observed during steadystate conditions for the same engine speed and load. With their joint action, the combustion noise during transient conditions is greater than that during steady-state conditions. Turbocharging is useful in reducing the combustion noise during transient conditions. Turbocharging has a better effect on the control over the combustion noise during transient conditions with a constant engine speed and an increasing torque than in conditions with a constant torque and an increasing engine speed. One of the main reasons for different control effects on the combustion noise is that turbocharging causes different wall temperatures inside combustion chambers. The introduction of the appropriate EGR is helpful in the reduction of the combustion noise during transient conditions. The key to the control of combustion noise with EGR during transient conditions is whether a real-time adjustment to the EGR rate can be made to achieve the optimization of the EGR rates for different transient conditions. By means of analyzing the differences in the combustion noise between the transient and steady-state conditions for different pilot injection controls, we obtain a strategy for controlling the combustion noise during transient conditions with a pilot injection. Compared with the steady-state conditions, a larger pilot injection quantity and a longer interval between the main injection and pilot injection should be selected for transient conditions, and this is verified through tests.     

直喷汽油机电控喷油系统的开发研究

开发了汽油直喷发动机电控喷油系统,选取飞思卡尔MC9S12DP512MPVE单片机作为发动机ECU的主控芯片,设计了喷油驱动电路模块,制订了不同工况下喷油控制策略.发动机试验证明,该电控喷油系统能提供不同工况所需喷射压力,符合设计的喷油控制策略,能够可靠保证发动机的喷油性能要求.     

氢燃料发动机及其起动过程研究

分析了不同氢燃料发动机供气系统的特点,在汽油机的基础上设计了氢燃料电控进气系统的硬件和控制策略。采用试验研究的方法,分析了喷氢量、喷气定时、点火提前角等参数对发动机起动过程的影响。研究结果表明,采用控制喷气脉宽和电子节气门的方法,可以有效实现发动机起动。起动工况较佳的喷气脉宽为7 000μs,点火提前角为10°CA,喷气定时为上止点后70°CA。     

Common rail injection system iterative learning control based parameter calibration for accurate fuel injection quantity control

This paper presents an accurate engine fuel injection quantity control technique for high pressure common rail (HPCR) injection systems by an iterative learning control (ILC)-based, on-line calibration method. Accurate fuel injection quantity control is of importance in improving engine combustion efficiency and reducing engine-out emissions. Current Diesel engine fuel injection quantity control algorithms are either based on pre-calibrated tables or injector models, which may not adequately handle the effects of disturbances from fuel pressure oscillation in HPCR, rail pressure sensor reading inaccuracy, and the injector aging on injection quantity control. In this paper, by using an exhaust oxygen fraction dynamic model, an on-line parameter calibration method for accurate fuel injection quantity control was developed based on an enhanced iterative learning control (EILC) technique in conjunction with HPCR injection system. A high-fidelity, GT-Power engine model, with parametric uncertainties and measurement disturbances, was utilized to validate such a methodology. Through simulations at different engine operating conditions, the effectiveness of the proposed method in rejecting the effects of uncertainties and disturbance on fuel injection quantity control was demonstrated.