According to advantages of neural network and characteristics of operatingprocedures of engine, a new strategy is represented on the control of fuel injection and ignitiontiming of gasoline engine based on improved BP...According to advantages of neural network and characteristics of operatingprocedures of engine, a new strategy is represented on the control of fuel injection and ignitiontiming of gasoline engine based on improved BP network algorithm. The optimum ignition advance angleand fuel injection pulse band of engine under different speed and load are tested for the samplestraining network, focusing on the study of the design method and procedure of BP neural network inengine injection and ignition control. The results show that artificial neural network technique canmeet the requirement of engine injection and ignition control. The method is feasible for improvingpower performance, economy and emission performances of gasoline engine.展开更多
The working principle of a kind of compositive emission control system is inquired into, which includes exhaust heater, secondary air supplement, exhaust gas recirculation (EGR), thermal reactor and catalytic conver...The working principle of a kind of compositive emission control system is inquired into, which includes exhaust heater, secondary air supplement, exhaust gas recirculation (EGR), thermal reactor and catalytic converter, etc. The purification effect of CO, HC and NOx emission of the gasoline spark ignite (S.I.) engine is studied. The entire vehicle driving cycle tests based on the national emission standard and a series of the gasoline engine-testing bench tests including full load characteristic experiment, load characteristic experiment and idle speed experiment are done. The results show that the system has a very good emission control effect to CO, HC and NOx of gasoline engine. The construction of the system is very simple and can be mounted on the exhaust pipe conveniently without any alteration of the vehicle-use gasoline engine.展开更多
Auto-ignition and heat release correlations for controlled auto-ignition(CAI)combustion were derived from extensive in-cylinder pressure data of a four-stroke gasoline engine operating in CAI combustion mode.Abundant ...Auto-ignition and heat release correlations for controlled auto-ignition(CAI)combustion were derived from extensive in-cylinder pressure data of a four-stroke gasoline engine operating in CAI combustion mode.Abundant experiments were carried out under a wide range of air/fuel ratio,speed and residual gas fraction to ensure that the combustion correlations can be used in the entire CAI engine operation range.Furthermore,a more accurate method to compute the residual gas fraction was proposed by calculating the working fluid temperature at the exhaust valve close timing in the experiments.The heat release correlation was described in two parts,one is for the first slower heat release process at low temperature,and the other is for the second faster heat release process at high temperature.Finally the heat release correlation was evaluated on the single cylinder gasoline engine running with CAI combustion by comparing the experimental data with the 1-D engine simulation results obtained with the aid of the GT-Power simulation program.The results show that the predicted loads and ignition timings match closely with the measurements.展开更多
For homogeneous charge compression ignition (HCCI) combustion, the auto-ignition process is very sensitive to in-cylinder conditions, including in-cylinder temperature, in-cylinder components and concentrations. The...For homogeneous charge compression ignition (HCCI) combustion, the auto-ignition process is very sensitive to in-cylinder conditions, including in-cylinder temperature, in-cylinder components and concentrations. Therefore, accurate control is required for reliable and efficient HCCI combustion. This paper outlines a simplified gasoline-fueled HCCI engine model implemented in Simulink environment. The model is able to run in real-time and with fixed simulation steps with the aim of cycle-to-cycle control and hardware- in-the-loop simulation. With the aim of controlling the desired amount of the trapped exhaust gas recirculation (EGR) from the previous cycle, the phase of the intake and exhaust valves and the respective profiles are designed to vary in this model. The model is able to anticipate the auto-ignition timing and the in-cylinder pressure and temperature. The validation has been conducted using a comparison of the experimental results on Ricardo Hydro engine published in a research by Tianjin University and a JAGUAR V6 HCCI test engine at the University of Birmingham. The comparison shows the typical HCCI combustion and a fair agreement between the simulation and experimental results.展开更多
To improve the responsiveness of engine speed control to disturbances, robust controls were investigated by simulation. The intake air control system of a gasoline engine is a typical nonlinear system, and the disturb...To improve the responsiveness of engine speed control to disturbances, robust controls were investigated by simulation. The intake air control system of a gasoline engine is a typical nonlinear system, and the disturbances and parameter perturbations are generally regarded as being the unstable factors with regard to engine control. In this paper, a Mean-Value Engine Model (MVEM) with disturbances and parameter perturbations is investigated using Sliding Mode Control (SMC), which is a form of variable structure control, with a view to address instability in the idle speed control process. The simulation results confirmed that, compared with a conventional PI (Proportional-Integral) controller, the stability of the idle speed for an engine that is being subjected to disturbances, parameter variations and background noise is greatly improved by the application of SMC.展开更多
Optimal engine torque management,a fundamental objective,depends predominantly on engine speed tracking performance.It ensures to attain desired speed profile in the presence of uncertainties,disturbances and malfunct...Optimal engine torque management,a fundamental objective,depends predominantly on engine speed tracking performance.It ensures to attain desired speed profile in the presence of uncertainties,disturbances and malfunctions.On the other hand,certain requirements such as emissions control,fuel efficiency and drivability are degraded in case of poorspeed tracking.Furthermore,constraints on engine speed tracking performance are even more stringent for hybrid power-train architecture as crankshaft speed and engine torque are the basic variables for coordinated control.Speed tracking is also considered essential for gearshift control ofthe automatic transmission.In this research work,a framework for fault-tolerant speed tracking of the gasoline engine is proposed using the First Principle-based Engine Model(FPEM).A high-fidelity direct relationship between fuel injection input and engine speed is derived by the transformation of FPEM.Fault is induced in the fuel injection subsystem to generate the torque imbalance.Using the proposed framework,a second-order sliding mode-based control technique is applied to track desired speed profile by mitigating the faultsin the fuel injection subsystem.Reference data acquired from the engine test rig is used to demonstrate the offline validity and fault tolerance capabilities of the proposed framework in MATLAB/Simulink.展开更多
基于不同废气再循环(exhaust gas recirculation,EGR)闭环控制方式的测量原理和控制策略,通过台架试验,对比稳态新鲜空气测量精度和瞬态排放,分析不同控制方式的控制精度及瞬态排放差异。结果表明:基于新鲜空气量和EGR率的2种闭环控制...基于不同废气再循环(exhaust gas recirculation,EGR)闭环控制方式的测量原理和控制策略,通过台架试验,对比稳态新鲜空气测量精度和瞬态排放,分析不同控制方式的控制精度及瞬态排放差异。结果表明:基于新鲜空气量和EGR率的2种闭环控制方式精度均较高,新鲜空气测量相对偏差分别小于±3%、±5%;基于废气氧浓度的闭环控制在低负荷区域的测量相对偏差最大达-10%;基于新鲜空气量的闭环控制在瞬态测试循环中EGR阀关闭速率快,NO x排放出现峰值;基于文丘里流量计的EGR率闭环控制可以有效兼顾新鲜空气和EGR废气流量,在满足柴油机动力性的同时有效控制排放污染物。展开更多
在一台4缸2.0 L汽油发动机上试验研究过量空气系数、有效压缩比、废气再循环(exhaust gas recircu-lation, EGR)率对发动机油耗和热效率的影响。结果表明:采用稀燃可以提高发动机热效率,过量空气系数由1.0增大到1.6,发动机热效率提高约5...在一台4缸2.0 L汽油发动机上试验研究过量空气系数、有效压缩比、废气再循环(exhaust gas recircu-lation, EGR)率对发动机油耗和热效率的影响。结果表明:采用稀燃可以提高发动机热效率,过量空气系数由1.0增大到1.6,发动机热效率提高约5.7%,但继续增大稀释程度将导致油耗增加、热效率降低;当有效压缩比为12.7时,发动机热效率最大,为44.1%,进一步增大压缩比产生爆震,需要推迟点火时刻,导致燃烧持续期增加、发动机热效率降低;EGR率为4.6%时,发动机热效率最大,为44.4%,EGR率较大导致燃烧不稳定,出现发动机失火等问题。展开更多
This paper presents a nonlinear observer-based control design approach for gasoline engines equipped with exhaust gas recirculation (EGR) system. A mean value engine model is designed for control which includes both t...This paper presents a nonlinear observer-based control design approach for gasoline engines equipped with exhaust gas recirculation (EGR) system. A mean value engine model is designed for control which includes both the in take manifold and exhaust manifold dynamic focused on gas mass flows. Then, the nonlinear feedback controller based on the developed model is designed for the state tracking control, and the stability of the close loop system is guaranteed by a constructed Lyapunov function. Since the exhaust manifold pressure is usually unmeasurable in the production engines, a nonlinear observer-based feedback controller is proposed by using standard sensors equipped on the engine, and the asymptotic stability of the both observer dynamic system and control dynamic system are guaranteed with Lyapunov design assisted by the detail analysis of the model. The experimental validations show that the observer-based nonlinear feedback controller is able to regulate the in take pressure and exhaust pressure state to the desired values during both the steady-state and transient conditions quickly by only using the standard sensors.展开更多
基于某4缸带外部废气再循环(exhaust gas recycle,EGR)功能的自然吸气汽油机,采用1D热力学和3DCFD耦合仿真的方法研究了部分负荷工况各缸EGR分配的均匀性,并在性能台架上研究了EGR分配不均对各缸燃烧速度的影响。研究结果表明:缸内实际...基于某4缸带外部废气再循环(exhaust gas recycle,EGR)功能的自然吸气汽油机,采用1D热力学和3DCFD耦合仿真的方法研究了部分负荷工况各缸EGR分配的均匀性,并在性能台架上研究了EGR分配不均对各缸燃烧速度的影响。研究结果表明:缸内实际EGR均匀性不仅与EGR系统设计有关,同时也受到各缸进气的均匀性的影响;EGR的不合理分配会导致各缸燃烧速率不均,继而增大燃烧循环波动率。基于所建立的1D/3D耦合分析方法,对EGR分配孔板结构进行了详细仿真优化,EGR分配均匀性得到显著改善。在随后的试验中,各缸燃烧一致性明显改善。展开更多
文摘According to advantages of neural network and characteristics of operatingprocedures of engine, a new strategy is represented on the control of fuel injection and ignitiontiming of gasoline engine based on improved BP network algorithm. The optimum ignition advance angleand fuel injection pulse band of engine under different speed and load are tested for the samplestraining network, focusing on the study of the design method and procedure of BP neural network inengine injection and ignition control. The results show that artificial neural network technique canmeet the requirement of engine injection and ignition control. The method is feasible for improvingpower performance, economy and emission performances of gasoline engine.
基金This project is supported by Provincial Natural Science Foundation of Guangdong, China and Provincial Environmental Protection Science Foundation of Guangdong, China(No.320-D38000).
文摘The working principle of a kind of compositive emission control system is inquired into, which includes exhaust heater, secondary air supplement, exhaust gas recirculation (EGR), thermal reactor and catalytic converter, etc. The purification effect of CO, HC and NOx emission of the gasoline spark ignite (S.I.) engine is studied. The entire vehicle driving cycle tests based on the national emission standard and a series of the gasoline engine-testing bench tests including full load characteristic experiment, load characteristic experiment and idle speed experiment are done. The results show that the system has a very good emission control effect to CO, HC and NOx of gasoline engine. The construction of the system is very simple and can be mounted on the exhaust pipe conveniently without any alteration of the vehicle-use gasoline engine.
基金Supported by State Key Project of Fundamental Research Plan(No.2007CB210004).
文摘Auto-ignition and heat release correlations for controlled auto-ignition(CAI)combustion were derived from extensive in-cylinder pressure data of a four-stroke gasoline engine operating in CAI combustion mode.Abundant experiments were carried out under a wide range of air/fuel ratio,speed and residual gas fraction to ensure that the combustion correlations can be used in the entire CAI engine operation range.Furthermore,a more accurate method to compute the residual gas fraction was proposed by calculating the working fluid temperature at the exhaust valve close timing in the experiments.The heat release correlation was described in two parts,one is for the first slower heat release process at low temperature,and the other is for the second faster heat release process at high temperature.Finally the heat release correlation was evaluated on the single cylinder gasoline engine running with CAI combustion by comparing the experimental data with the 1-D engine simulation results obtained with the aid of the GT-Power simulation program.The results show that the predicted loads and ignition timings match closely with the measurements.
文摘For homogeneous charge compression ignition (HCCI) combustion, the auto-ignition process is very sensitive to in-cylinder conditions, including in-cylinder temperature, in-cylinder components and concentrations. Therefore, accurate control is required for reliable and efficient HCCI combustion. This paper outlines a simplified gasoline-fueled HCCI engine model implemented in Simulink environment. The model is able to run in real-time and with fixed simulation steps with the aim of cycle-to-cycle control and hardware- in-the-loop simulation. With the aim of controlling the desired amount of the trapped exhaust gas recirculation (EGR) from the previous cycle, the phase of the intake and exhaust valves and the respective profiles are designed to vary in this model. The model is able to anticipate the auto-ignition timing and the in-cylinder pressure and temperature. The validation has been conducted using a comparison of the experimental results on Ricardo Hydro engine published in a research by Tianjin University and a JAGUAR V6 HCCI test engine at the University of Birmingham. The comparison shows the typical HCCI combustion and a fair agreement between the simulation and experimental results.
文摘To improve the responsiveness of engine speed control to disturbances, robust controls were investigated by simulation. The intake air control system of a gasoline engine is a typical nonlinear system, and the disturbances and parameter perturbations are generally regarded as being the unstable factors with regard to engine control. In this paper, a Mean-Value Engine Model (MVEM) with disturbances and parameter perturbations is investigated using Sliding Mode Control (SMC), which is a form of variable structure control, with a view to address instability in the idle speed control process. The simulation results confirmed that, compared with a conventional PI (Proportional-Integral) controller, the stability of the idle speed for an engine that is being subjected to disturbances, parameter variations and background noise is greatly improved by the application of SMC.
文摘Optimal engine torque management,a fundamental objective,depends predominantly on engine speed tracking performance.It ensures to attain desired speed profile in the presence of uncertainties,disturbances and malfunctions.On the other hand,certain requirements such as emissions control,fuel efficiency and drivability are degraded in case of poorspeed tracking.Furthermore,constraints on engine speed tracking performance are even more stringent for hybrid power-train architecture as crankshaft speed and engine torque are the basic variables for coordinated control.Speed tracking is also considered essential for gearshift control ofthe automatic transmission.In this research work,a framework for fault-tolerant speed tracking of the gasoline engine is proposed using the First Principle-based Engine Model(FPEM).A high-fidelity direct relationship between fuel injection input and engine speed is derived by the transformation of FPEM.Fault is induced in the fuel injection subsystem to generate the torque imbalance.Using the proposed framework,a second-order sliding mode-based control technique is applied to track desired speed profile by mitigating the faultsin the fuel injection subsystem.Reference data acquired from the engine test rig is used to demonstrate the offline validity and fault tolerance capabilities of the proposed framework in MATLAB/Simulink.
文摘基于不同废气再循环(exhaust gas recirculation,EGR)闭环控制方式的测量原理和控制策略,通过台架试验,对比稳态新鲜空气测量精度和瞬态排放,分析不同控制方式的控制精度及瞬态排放差异。结果表明:基于新鲜空气量和EGR率的2种闭环控制方式精度均较高,新鲜空气测量相对偏差分别小于±3%、±5%;基于废气氧浓度的闭环控制在低负荷区域的测量相对偏差最大达-10%;基于新鲜空气量的闭环控制在瞬态测试循环中EGR阀关闭速率快,NO x排放出现峰值;基于文丘里流量计的EGR率闭环控制可以有效兼顾新鲜空气和EGR废气流量,在满足柴油机动力性的同时有效控制排放污染物。
文摘在一台4缸2.0 L汽油发动机上试验研究过量空气系数、有效压缩比、废气再循环(exhaust gas recircu-lation, EGR)率对发动机油耗和热效率的影响。结果表明:采用稀燃可以提高发动机热效率,过量空气系数由1.0增大到1.6,发动机热效率提高约5.7%,但继续增大稀释程度将导致油耗增加、热效率降低;当有效压缩比为12.7时,发动机热效率最大,为44.1%,进一步增大压缩比产生爆震,需要推迟点火时刻,导致燃烧持续期增加、发动机热效率降低;EGR率为4.6%时,发动机热效率最大,为44.4%,EGR率较大导致燃烧不稳定,出现发动机失火等问题。
文摘This paper presents a nonlinear observer-based control design approach for gasoline engines equipped with exhaust gas recirculation (EGR) system. A mean value engine model is designed for control which includes both the in take manifold and exhaust manifold dynamic focused on gas mass flows. Then, the nonlinear feedback controller based on the developed model is designed for the state tracking control, and the stability of the close loop system is guaranteed by a constructed Lyapunov function. Since the exhaust manifold pressure is usually unmeasurable in the production engines, a nonlinear observer-based feedback controller is proposed by using standard sensors equipped on the engine, and the asymptotic stability of the both observer dynamic system and control dynamic system are guaranteed with Lyapunov design assisted by the detail analysis of the model. The experimental validations show that the observer-based nonlinear feedback controller is able to regulate the in take pressure and exhaust pressure state to the desired values during both the steady-state and transient conditions quickly by only using the standard sensors.
文摘基于某4缸带外部废气再循环(exhaust gas recycle,EGR)功能的自然吸气汽油机,采用1D热力学和3DCFD耦合仿真的方法研究了部分负荷工况各缸EGR分配的均匀性,并在性能台架上研究了EGR分配不均对各缸燃烧速度的影响。研究结果表明:缸内实际EGR均匀性不仅与EGR系统设计有关,同时也受到各缸进气的均匀性的影响;EGR的不合理分配会导致各缸燃烧速率不均,继而增大燃烧循环波动率。基于所建立的1D/3D耦合分析方法,对EGR分配孔板结构进行了详细仿真优化,EGR分配均匀性得到显著改善。在随后的试验中,各缸燃烧一致性明显改善。