Decoupled self-tuning PI controller for an idling stop system applied to scooters

This paper is aimed to propose a decoupled self-tuning proportional plus integral (PI) controller with simple law for an idling stop system applied to scooters. An integrated starter generator (ISG) of the idling stop system is designed with a high efficiency permanent magnet synchronous motor (PMSM). The PMSM used as an ISG must have a high torque characteristic to ensure that the engine can be accelerated up to firing speed. A conventional and useful control algorithm named PI control is unable to handle motor current very well for dynamic load, parametric variation, and external disturbance, especially in a vehicle application. Therefore, a robust algorithm for current control in an ISG is proposed. The decoupled selftuning PI controller based on the Lyapunov stability theorem is utilized to guarantee the control performance. Numerical simulations demonstrate the effectiveness of the proposed control algorithm. Experimental results show that the engine of a 150 cm3 scooter can be cranked to reach firing speed by a ISG within 0.1?0.2 second. The proposed method is simple, robust, as well as stable for idling stop system, and can be effectively implemented.     

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.     

发动机智能怠速停止起动系统控制策略的研究

在介绍了发动机怠速停止起动系统工作原理的基础上,分析了发动机怠速和重新起动时的燃油消耗量,以及目前怠速停止起动系统的缺点。结果表明,短时间的怠速停止反而会因需要重新起动而增加发动机油耗。为此设计了一种汽车发动机智能怠速停止起动系统的控制策略,它能够根据交通信号灯确定的停车时间的长短来决定是否执行怠速停止。     

Powertrain design and experiment research of a parallel hybrid electric vehicle

The powertrain of an ultra-capacitor-based parallel hybrid electric vehicle (HEV) was developed. Innovations, such as the engine management system, floating ISG (Integrated Starter and Generator), electronic-controlled double-clutch system and dual-driven air conditioning system were realized. Hybrid control strategies to improve the fuel economy and reduce emissions were analyzed briefly. In order to ensure the vehicle emission performance, the engine management system calibration was performed. The vehicle emission test was also conducted, showing that the vehicle emission satisfied the EURO III standard and has great potential for improvement. The hybrid start test was introduced in detail. We realized the hybrid function and start parameter optimization of the engine and ISG.     

利用瞬时转速对柴油机起动过程的分析

建立柴油机起动过程试验系统,并利用瞬时转速分析不同拖动时间、不同拖动转矩和不同供油量等条件对柴油机起动过程的影响。试验结果表明利用瞬时转速能够判断柴油机着火首循环以及辅助分析燃烧组织的优劣。适当增加拖动时间、提高拖动转矩有利于改善柴油机起动性能。增加起动过程中的供油量,有助于发动机快速进入怠速稳定转速。     

Analysis on fuel economy and advanced systems of hybrid vehicles

Basic ideas on operation of hybrid vehicles were discussed from a view point of energy saving. Almost double fuel economy of series–parallel–hybrid vehicles was estimated on condition of no engine idling during vehicle stop, energy saving in acceleration using brake energy recovery and high efficiency operation on low load condition using series–hybrid system. From the discussion of overall efficiency, involving fuel cycle, under both low and high load conditions, both series–parallel–hybrid vehicles with internal combustion engine and fuel cell are supposed to have a high potential for the future.     

基于OpenFOAM的发动机舱回流计算方法研究

研究车辆在怠速工况下的发动机舱热空气回流问题，基于OpenFOAM 软件进行回流计算方法的开发。通过设置监控面及组分转换面来重新定义格栅新空气和舱内回流热空气等组分，可直接计算出回流在监控面上的分布及回流率和回流量。根据开发的方法对某款插电式混合动力汽车（Plug-in Hybrid Electric Vehicle，PHEV）车型进行计算并提出不同的优化方案，使其发动机舱回流率从32.7% 分别降低至24.0%和9.3%，回流量从0.169 kg/s分别降低至0.128 kg/s和0.048 kg/s，从而降低了冷凝器等散热器的进风温度，提高了怠速工况下热管理系统的性能。     

单轴并联式混合动力总成的设计

设计完成了驱动电机与电控共轨柴油机结合而成的混合动力汽车动力总成,该总成用于单轴并联式混合动力汽车。驱动电机既是电驱动装置,又是起动、发电一体化系统(ISG),基于MC 68H9S12DP256B单片机,研制了该总成的控制系统,通过CAN总线实现了联合控制,以电池充放电平衡和发动机燃油经济性为基础,应用了一种模糊逻辑控制策略,实现了混合动力系统的扭矩分配与不同工作模式以及模式间的切换,该总成能够在所要求的工作模式下运转。     

电喷发动机闭缸循环工作排放与经济性试验研究

介绍了电喷发动机闭缸循环工作节油的理论基础,给出了闭缸循环工作的控制电路和工作模式,并进行了怠速和等速行驶燃油消耗和排放性能的对比试验。试验结果表明,两缸闭缸循环工作能够有效地降低燃油消耗量。     

混合动力汽车转矩分配策略优化研究

以搭载改型后的Atkinson循环发动机并带有双离合器的单轴并联式混合动力三厢轿车为研究对象,采用逻辑门限值控制方法对发动机和电机的转矩进行合理分配,使混合动力系统在各种行驶工况模式下能够实时切换到高效工作区;引入各个驾驶工况模式控制策略的瞬时优化算法,进一步提高混合动力总成系统的整体效率。仿真和试验对比分析表明,提出的控制策略能够有效地降低NEDC循环工况百公里油耗,提高了搭载Atkinson循环发动机混合动力汽车的燃油经济性。     

Active coolant control strategies in automotive engines

The coolant flow rate in conventional cooling systems in automotive engines is subject to the mechanical water pump speed, and high efficiency in terms of fuel economy and exhaust emission is not possible given this limitation. A new technology must be developed for engine cooling systems. The electronic water pump is used as a substitute for the mechanical water pump in new engine cooling systems. The new cooling system provides more flexible control of the coolant flow rate and engine temperature, which previously relied strongly on engine driving conditions such as load and speed. In this study, the feasibility of two new cooling strategies was investigated using a simulation model that was validated with temperatures measured in a diesel engine. Results revealed that active coolant control using an electronic water pump and valves substantially contributed to a reduction of coolant warm-up time during cold engine starts. Harmful emissions and fuel consumption are expected to decrease as a result of a reduction in warm-up time.     

稀薄燃烧发动机改型设计及正时策略优化

基于某高速汽油机,对燃烧室结构、燃油喷射特性、凸轮型线改型设计为稀薄燃烧发动机。提出利用响应面模型对正时策略进行分析和优化的研究方法,并建立利用响应面进行多目标优化计算的流程。以提高有效功率和降低有效燃油消耗率为优化目标,以点火正时、空燃比和进排气正时为设计变量,建立了发动机性能与响应面耦合优化模型。分析与试验结果表明:较标准混合比燃烧时,稀薄燃烧发动机的进排气提前角减小,点火正时提前,最低燃油消耗率下降3.9%,最大功率提升9.7%;同时利用响应面优化方法提高了优化效率。     

基于增益功率燃油系数的HEV能量管理策略

为了优化等效燃油最小能量管理策略的节油效果，以适用于工程批量应用为导向，制定基于增益功率燃油系数的混合动力汽车(HEV)能量管理策略。基于瞬时优化原理，提出基于增益功率燃油系数的工作模式决策机制，根据电机发电或电动引起的发动机功率与燃油消耗率的变化关系，分别给出电机充电和放电模式下增益功率燃油系数的计算方法。考虑发动机扭矩瞬态快速变化对油耗的影响和电机及电池包充放电效率特性，提出发动机高效区域扭矩滞回控制方法，建立基于增益功率燃油系数的能量管理策略算法架构。基于MATLAB/Simulink搭建控制策略软件模型，通过转鼓试验台进行实车试验验证。研究结果表明：相对于等效燃油最小能量管理策略，基于增益功率燃油系数的能量管理策略提升了节油率和舒适性，在全球轻型汽车测试循环(WLTC)工况下的百公里油耗降低了约4.8%，发动机的启停次数降低了约53%；相对于有效燃油消耗率(BSFC)最优工作点控制方法，发动机高效区域滞回控制方法降低百公里油耗约1.8%；与采用基于动态规划的全局优化能量管理策略的仿真结果对比，在不能提前预知工况的条件下，制定的能量管理策略在WLTC工况与新标欧洲测试循环(NEDC)工况下的油耗与理论最优值差距均较小。     

ISG混合动力汽车整车控制器的设计

根据ISG用于带增压柴油机的混合动力汽车的特点,设计了基于CAN总线的ISG混合动力汽车的整车控制器,包括硬件的模块化设计、CAN总线的应用设计及针对废气涡轮增压柴油机的ISG混合动力汽车控制策略设计,并且详细介绍了其硬件设计方法以及部分主要模块和算法的程序流程图.实验结果表明,该控制器功能强大、性能可靠,能准确实现带增压柴油机的ISG混合动力汽车的整车控制策略.     

车用汽油发动机空燃比及点火控制系统

本文介绍了自行研制的ＣＡ４８８Ｑ发动机空燃比及点火控制系统，详细介绍了系统的组成和空燃比及点火提前角的控制方法，台架实验结果表明，采用该系统后ＣＡ４４８Ｑ发动机的动力性，经济性及怠速稳定性都较原化油器发动机有明显的改善。     

Development of an Active Control Engine Mount System

In an attempt to reduce idling vibration and booming noise in automobile engines, the authors have developed an engine mounting system we call the ACM(Active Control engine Mount) system. Comprising a pair of electromagnetic actuators and hydraulic mounts, the system incorporates an adaptive control strategy based on the synchronized filtered-X LMS (SFX) algorithm. The crank angle pulse signal is detected as the synchronization signal and the force transmitted to the car body through the engine mounts is detected as a residual signal. Application of the ACM system to a vehicle with a transversally mounted four-cylinder engine resulted in significantly reduced idling vibration and booming noise.     

Development of an Active Control Engine Mount System

In an attempt to reduce idling vibration and booming noise in automobile engines, the authors have developed an engine mounting system we call the ACM(Active Control engine Mount) system. Comprising a pair of electromagnetic actuators and hydraulic mounts, the system incorporates an adaptive control strategy based on the synchronized filtered-X LMS (SFX) algorithm. The crank angle pulse signal is detected as the synchronization signal and the force transmitted to the car body through the engine mounts is detected as a residual signal. Application of the ACM system to a vehicle with a transversally mounted four-cylinder engine resulted in significantly reduced idling vibration and booming noise.     

ISG柴油混合动力客车能量分配策略研究

以ISG柴油混合动力客车整车控制策略为基础,综合考虑客车燃油经济性和排放,提出一种基于模糊神经网络的能量分配策略,该策略根据模糊控制原理,结合人工神经网络自主学习功能,以电池SOC、整车需求转矩以及发动机转速为模糊输入来确定发动机和电机的最佳输出转矩分配,再以神经网络对控制的模糊规则进行记忆.仿真结果表明,该策略比普通逻辑控制更加有利于燃油经济性的提高,并在一定程度上改善了排放性能.     

进气门关闭状态下喷油时刻对汽油机性能的影响

为了改善进气道喷射式发动机性能,采用台架试验和数值计算的方法对喷油时刻与进气道喷射式汽油机性能之间的关系进行了研究。研究结果表明：在进气门关闭状态下进行燃油喷射,发动机运行工况不同,喷油时刻对发动机性能的影响规律不同,小节气门开度时推迟喷油时刻会导致 HC 排放升高和发动机动力性下降,大节气门开度时喷油时刻的改变对发动机性能的影响可以忽略。通过数值计算分析发现该变化规律与附壁油膜挥发速率有直接关系,在小节气门开度条件下,附壁油膜无法完全挥发,会增加燃油以液态形式进入气缸的量,从而使发动机性能下降,而处于大节气门条件下,较高的机体温度使得附壁油膜挥发速率加快,降低液态燃油的量,从而改善发动机性能。因此,进气道喷射发动机可以在小节气门开度时采用两次燃油喷射方式提升发动机性能,而在大节气门开度下则无需考虑喷油时刻的影响。     

Approach to minimization of piston slap force for noise reduction – investigation of piston slap force by numerical simulation

Impact force caused by piston slap is one of the major mechanical noise sources in a diesel engine. The optimization of piston pin offset for impact force reduction has been reported by many researchers. However, if a modification has large effect at idling, high-speed noise tends to increase and vice versa. It was very difficult to reduce piston slap noise at all engine speeds. In this paper, the mechanism of the piston slap was investigated precisely utilizing numerical simulation. Simultaneous noise reduction in the conditions of both idling and high speed was achieved successfully by optimizing the piston's center of gravity as well as piston pin offset. Furthermore, engine sound quality was also significantly improved.