基于智能控制的汽车发动机可变配气相位系统

提出了基于智能控制的发动机可变配气相位控制方法。采用神经网络构成配气相位产生器,解决了发动机脉谱图的输入与输出非线性映射问题。采用模糊控制器构成可变配气相位控制系统,解决了在无被控对象数学模型的情况下,可变配气相位难以有效控制问题。汽车道路试验表明:整个系统工作稳定,具有良好的动态和稳态性能,高速时汽车等速燃油消耗平均下降了10％,直接挡加速时间下降了4.8％,最低稳定车速限值降低了8.3％。     

一种新型发动机可变配气相位与气门升程机构的设计

本文分析了可变配气相位技术的研究现状,提出了一种新的发动机可变配气相位与气门升程机构的设计思路,能方便实现对进、排气门的配气相位及气门升程的全范围控制。     

配气机构优化技术的发展现状和趋势

配气机构是发动机的重要组成部分,其性能的优劣决定着发动机性能。文中从发动机目前使用的配气机构技术、配气机构优化参数以及配气机构优化方式等几个方面介绍了国内外配气机构发展现状和发展趋势。配气机构将会朝着气门升程、配气相位及进气管都可变的全可变技术和无凸轮轴可变技术方向发展。     

电液气门驱动系统动态特性分析

电液气门驱动系统是一种新的可变配气相位技术，可实现气门开启的全可变控制。该文基于AMESim软件，建立了电液气门驱动系统的一种仿真模型，计算并分析了影响气门动态性能的因素，为进一步研究电液气门驱动系统，提供了有用的帮助。     

基于神经网络的动态逆方法研究

该文探讨了神经网络与非线性动态逆方法相结合的神经网络动态逆方法，研究了神经网络动态逆的网络结构。为进一步改善直接动态逆控制器的性能，对由动态逆和原系统构成的伪线性系统，给出了两种综合方案。通过仿真研究表明，综合控制策略不仅能够改善系统的动态性能，而且具有良好的鲁棒性。研究成果显示了神经网络动态逆方法的有效性和可行性以及在控制系统设计中所具有的潜在能力。     

汽车车道保持系统的BP神经网络控制

针对汽车侧向动力学的强非线性且参数时变特性，利用神经网络对任意非线性函数的逼近能力，并结合驾驶员操纵行为特性，建立了基于BP神经网络的汽车车道保持系统的自适应PID控制算法。不同车速和路况的仿真结果表明，该控制算法可有效地控制汽车按照预期轨迹行驶，且对车速和道路曲率的变化具有较强的适应性和鲁棒性。     

汽油机可变配气正时机构的数值模拟

可变配气正时系统是汽车工业发展的一个重要的技术成果。目前,它已作为提高发动机性能运用的最广泛通用技术运用在发动机上。进气气流在进气道和气门附近受到的阻力较大,直接导致发动机性能下降。传统的发动机配气系统,只能优化发动机在某些特定工况(如高转速、高负荷)下的性能。相较传统的发动机配气正时相位不改变的状态,可变气门正时技术可以有效适配发动机所有运作工况。这对于提高发动机的性能,具有十分明显的好处。     

汽车半主动悬架系统神经网络模型研究

基于磁流变减振器的汽车悬架系统具有明显的滞后非线性,系统中的非线性阻尼和非线性刚度等对其动力学行为产生了很大的影响。本文利用系统识别理论建立了磁流变减振器的神经网络模型,该模型可根据半主动悬架系统的控制力求得控制电流,具有良好的辩识能力。     

汽车涂装输送用新型混联机构的动力学控制

对一种汽车电泳涂装输送用新型混联机构进行动力学控制研究。首先采用拉格朗日法推导出混联机构动力学模型。其次,基于构建的动力学模型设计了一种PD滑模神经网络控制器并进行了稳定性证明。最后,通过MATLAB仿真并与PD滑模控制器的仿真结果进行比较,结果表明:所提出PD滑模神经网络控制器由于具有神经网络的前馈控制有效解决了PD滑模控制器存在的剧烈抖振问题,使得汽车电泳涂装输送控制系统呈现良好的控制性能。     

汽车电泳涂装输送用新型混联机构的动力学控制

由于汽车电泳涂装输送用新型混联机构存在高度非线性和耦合性,因此难以实现高性能控制。为此,首先采用拉格朗日法推导该机构的动力学模型。然后,在任务空间设计一种PD滑模神经网络动力学控制器并进行稳定性证明。最后,对该控制器进行了仿真,并将所得结果与PD滑模控制器仿真结果进行比较。比较结果表明：该动力学控制器通过神经网络前馈控制的作用有效解决了PD滑模控制器存在的剧烈抖振问题,使得汽车电泳涂装输送控制系统呈现良好的控制性能。     

A hybrid disturbance rejection control solution for variable valve timing system of gasoline engines

A novel solution for electro-hydraulic variable valve timing (VVT) system of gasoline engines is proposed, based on the concept of active disturbance rejection control (ADRC). Disturbances, such as oil pressure and engine speed variations, are all estimated and mitigated in real-time. A feed-forward controller was added to enhance the performance of the system based on a simple and static first principle model, forming a hybrid disturbance rejection control (HDRC) strategy. HDRC was validated by experimentation and compared with an existing manually tuned proportional-integral (PI) controller. The results show that HDRC provided a faster response and better tolerance of engine speed and oil pressure variations.     

基于黑箱模型和RBF-PID的HCCI发动机燃烧正时控制

由于均质充气压缩点燃(HCCI)发动机缺少直接控制其燃烧的手段,导致HCCI发动机的燃烧正时控制成为HCCI发动机的研究热点。以HCCI发动机进气歧管的温度和压力、燃油当量比、转速以及进气门关闭正时为输入,利用BP神经网络建立用于估计HCCI发动机燃烧正时的黑箱模型。在此模型基础上,以进气门关闭正时为控制量设计了PID控制器,并利用径向基神经网络对其参数进行整定,以实现对燃烧正时的反馈控制。实验结果表明,BP神经网络估计模型对HCCI发动机燃烧正时的估计误差小于0.4(CAD),能实现准确的估计;此外,与传统的PID控制器相比,设计的RBF-PID控制器在超调量、调节时间以及抗干扰性等性能方面均有改善。     

用于气动伺服系统的自适应神经模糊控制器

研究了一种基于压力比例阀的气动伺服系统自适应神经模糊控制器。其中的神经网络辨识器（NNI）通过高线训练可以充分逼近非线性动态系统的模型,并能够在线调整模糊控制器的控制规则。系统的位置控制精度和伺服特性有了很大改善。试验结果表明,所提出的控制器对该气动伺服系统具有很好的控制特性以及很强的自适应能力。     

Design of an optimal idle speed controller for a turbocharged diesel engine using fuzzy logic method

Idle Control of Internal Combustion Engines (ICEs) is one of the most important modules of Engine Management Systems (EMS) due to its effects on fuel consumption (FC) and pollutions produced in urban traffics. PID controllers are usually used for idle speed regulation. In this paper a PID like fuzzy controller is used to control the idle speed. The aim of this research is to introduce the selection method of membership functions for nonlinear processes which have unsymmetrical behaviors around working point. Also a simple yet useful graphical base approach to optimize fuzzy like PID controller is introduced. In order to design the controller a mean value model of a 1.6 turbocharged diesel engine is applied. In this model the effects of injection timing, injected fuel mass, ambient conditions and cycle by cycle torque generation variations are taken into account. The model also predicts the engine behavior in warm-up period. Two main manipulated variables of injection timing and injected fuel mass per cycle are handled to control the engine speed under different sources of engine speed variation such as external loads made by A/C, steering hydraulic pump or alternator and also the internal loads e.g. variable internal friction. The designed controller shows high robustness in response to change in ambient conditions.     

Modeling and fuzzy control of the engine coolant conditioning system in an IC engine test bed

Mechanical and thermodynamical performance of internal combustion engines is significantly affected by the engine working temperature. In an engine test bed, the internal combustion engines are tested in different operating conditions using a dynamometer. It is required that the engine temperature be controlled precisely, particularly in transient states. This precise control can be achieved by an engine coolant conditioning system mainly consisting of a heat exchanger, a control valve, and a controller. In this study, constitutive equations of the system are derived first. These differential equations show the second-order nonlinear time-varying dynamics of the system. The model is validated with the experimental data providing satisfactory results. After presenting the dynamic equations of the system, a fuzzy controller is designed based on our prior knowledge of the system. The fuzzy rules and the membership functions are derived by a trial and error and heuristic method. Because of the nonlinear nature of the system the fuzzy rules are set to satisfy the requirements of the temperature control for different operating conditions of the engine. The performance of the fuzzy controller is compared with a PI one for different transient conditions. The results of the simulation show the better performance of the fuzzy controller. The main advantages of the fuzzy controller are the shorter settling time, smaller overshoot, and improved performance especially in the transient states of the system.     

发动机进气VVT调节速度超标的解决方法

发动机VVT能够对发动机的进排气门开启、关闭时间及进气量进行连续调节,从而提高发动机功率,优化转矩曲线.解锁特性、调节速度以及控制稳定性是VVT三大关键特性,如过程出现超标会直接影响发动机的动力性、经济性以及排放指标.以某四缸直喷汽油发动机进气VVT超标为例,利用故障树分析法建立VVT超标故障的FTA,逐步进行分析验证...     

双阀并联电液伺服力控系统的迭代学习控制

针对大部分舵机电液伺服力控系统存在多余力的问题,提出采用双电液伺服阀并联控制,即高响应大流量伺服阀和p-qv伺服阀并联的控制方法.考虑系统的非线性和时变特性,采用了模糊控制与迭代学习控制相结合的控制方法,即一个控制器采用模糊学习控制,另一个采用迭代PI控制.理论分析及仿真结果表明,双阀并联控制方案在舵机启动和停车过程中可以更好地抑制多余力,同时改善了系统的加载性能、非线性和时变特性的影响.     

基于模糊BP网络的自适应PID控制

针对经典PID控制的参数不能在线调整的缺陷,提出了一种基于模糊BP神经网络的PID控制算法,采用模糊规则自动地调节BP神经网络训练过程的学习参数,利用神经网络较强的学习能力和模糊控制在模型未知或不精确前提下的控制能力,将其应用到PID控制中[1],实现了PID控制参数的在线调整和优化,并对其在非线性离散系统中的应用进行了仿真。实验结果表明该算法性能优良,加快了系统响应速度,减少了超调量,适用于纯滞后非线性系统。     

A new electromagnetic engine valve actuator with less energy consumption for variable valve timing

A variable valve timing (VVT) can improve fuel efficiency, reduce CO2 emissions and increase torque output enabling optimization of these outputs at different engine conditions. To achieve VVT in internal combustion engine, new devices such as mechanical, hydraulic, motor-driven and electromagnetic actuators have been developed in past years to replace the conventional camshaft valve train system used currently. Among these, the electromagnetic actuator using solenoids is the most advanced system to provide the most flexibility to valve timing, but it has critical drawback of high power consumption. In this paper, a new electromagnetic engine valve actuator that uses permanent magnets to latch the valve is introduced.