基于MATLAB/Simulink的双动力匹配与控制仿真

针对双动力装置中发动机控制特点,提出了恒速控制和转速反馈闭环控制的复合控制策略。建立了发动机主从控制器的Simulink仿真模型,进行了仿真研究。仿真结果表明,主从控制法可以解决双机并车运行过程中的关键问题,即负荷分配问题,能保证双机运行时发动机转速的稳定性和负荷分配的合理性。     

DYNAMIC MODEL AND SIMULATION OF A NOVEL ELECTRO-HYDRAULIC FULLY VARIABLE VALVE SYSTEM FOR FOUR-STROKE AUTOMOTIVE ENGINES

In modern four-stroke engine technology, variable valve timing and lift control offers potential benefits for making a high-performance engine. A novel electro-hydraulic fully variable valve train for four-stroke automotive engines is introduced. The construction of the nonlinear mathematic model of the valve train system and its dynamic analysis are also presented. Experimental and simulation results show that the novel electro-hydraulic valve train can achieve fully variable valve timing and lift control. Consequently the engine performance on different loads and speeds will be significantly increased. The technology also permits the elimination of the traditional throttle valve in the gasoline engines and increases engine design flexibility.     

压缩空气/燃油混合动力发动机工作特性的数值模拟

以一种四行程压缩空气/燃油混合动力发动机为研究对象,应用热力学理论建立了它的两种工作模式———四行程压缩空气动力模式和内燃机模式的数学模型,并对两种工作模式的工作特性进行了仿真研究。仿真结果表明,转速在低于1500r/min时,四行程压缩空气动力模式具有良好的经济性和动力性能;转速在1500～3500r/min范围内时,内燃机模式具有良好的经济性和动力性能。故知,四行程压缩空气动力模式适宜在低速、低负荷时运行,而内燃机模式适宜在高速、大负荷时运行。     

Idle speed modeling and optimal control of a spark-ignition engine

A model of engine dynamics is developed. The model is a MISO (Multi Input Single Output) linear model which has two inputs and one output. One input is the spark timing, and the other is the ISCV (Idle Speed Control Valve) position. The output is the angular speed of an engine. The reliability of the developed model is confirmed by comparing the measured response of the engine to step inputs and external disturbance with the simulation results. In order to reduce the steady state error, an integrator state is inserted to the state equation. An engine idle speed controller is designed using optimal control theory based on the model. The performance variation of the controller to the various design parameters is simulated. On the basis of the simulation and the experimental data, the design parameters are determined. The developed controller reduced the idle speed drop caused by an external load change and recovered the desired idle speed in one second.     

工程机械混合动力系统设计与仿真

阐述了工程机械混合动力系统设计原理,介绍了混合动力系统结构及设计方法,利用MATLAB/Simulink软件建立了整机动力学及发动机、电动机模型,并对传统动力系统和混合动力系统进行了仿真。仿真试验的对比结果表明,混合动力系统不仅能提高工作效率和降低燃油消耗,还可有效地减少环境污染,延长机械的使用寿命。     

具有混合约束的离散事件系统的Petri网控制器的研究

针对由Petri网建模的离散事件系统中具有混合约束的Petri网控制器的设计问题,利用局部设计和Petri网简化技术改进与完善控制器的设计方法,并证明所提方法是最大容许的.先利用局部设计Petri网简化技术把所有约束库所融合为一个与它们标识总量相等的库所,然后再与受约束的变迁进行对照比较,使控制器的设计更为简单并且避免了死锁,尤其是对规模较大的系统,其优势更加明显.针对于约束的不同情况,给出了相应的控制器设计方法,最后通过几个例子对该方法的简单性和有效性进行了验证.     

发动机工作原理模拟机构的设计与仿真

对单缸四冲程汽车发动机工作原理进行了分析,确定了汽车发动机工作原理模拟机构的简化设计方案,基于Pro/E自顶向下的设计方法,建立了汽车发动机工作原理模拟机构的缸体模型。在缸体模型里设计了曲轴滑块机构、正时与配气系统,并在Pro/E的Mechanism模块中进行了运动学仿真分析,实现了发动机工作原理模拟机构的四冲程模拟运动仿真。该模拟机构能够演示汽车发动机四个冲程的工程过程,具有操作简单、携带方便、原理易懂、成本低廉等特点。     

混合动力汽车的电机启动发动机过程仿真研究

研究了在混合动力车用发动机断油条件下,利用电机调速控制方法降低发动机产生的负载扭矩的可行性。运用MATLAB/Simulink软件建立了四缸柴油发动机、永磁同步电机和电机控制器的数学模型,通过数字仿真分析了混合动力车用发动机启动过程中的负载扭矩特性。仿真结果表明,对比最大扭矩控制算法,采用离散模糊PID控制算法可以快速启动发动机并可有效地将发动机转速控制在目标转速附近规律波动,这有助于降低发动机产生的负载扭矩。     

Generator voltage stabilisation for series-hybrid electric vehicles

This paper presents a controller for use in speed control of an internal combustion engine for series-hybrid electric vehicle applications. Particular reference is made to the stability of the rectified DC link voltage under load disturbance. In the system under consideration, the primary power source is a four-cylinder normally aspirated gasoline internal combustion engine, which is mechanically coupled to a three-phase permanent magnet AC generator. The generated AC voltage is subsequently rectified to supply a lead-acid battery, and permanent magnet traction motors via three-phase full bridge power electronic inverters. Two complementary performance objectives exist. Firstly to maintain the internal combustion engine at its optimal operating point, and secondly to supply a stable 42 V supply to the traction drive inverters. Achievement of these goals minimises the transient energy storage requirements at the DC link, with a consequent reduction in both weight and cost. These objectives imply constant velocity operation of the internal combustion engine under external load disturbances and changes in both operating conditions and vehicle speed set-points. An electronically operated throttle allows closed loop engine velocity control. System time delays and nonlinearities render closed loop control design extremely problematic. A model-based controller is designed and shown to be effective in controlling the DC link voltage, resulting in the well-conditioned operation of the hybrid vehicle.     

Friction model of a marine diesel engine piston assembly

In modern marine diesel engines, power output and in-cylinder firing pressures are constantly increasing, leading to higher friction in engine components and especially in the piston assembly. A good understanding of the friction contributions of the various engine components is needed, if mechanical efficiency is to be improved. A friction model for the engine piston assembly has been developed and is presented in this paper. The model, based on lubrication theory, considers the detailed engine geometry and the complete lubricant action, and thus can be applied to a wide range of engines. In detail, the analysis takes into account the friction components of compression rings, oil control rings, piston skirt and gudgeon pin of the engine piston assembly. The model was applied to a four-stroke (medium speed) marine diesel engine and the effect of engine speed and load on friction was examined and compared with results from other semi-empirical models. The engine friction was predicted at constant rotational speed (generator operation) and variable rotational speed (propulsion operation).     

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.     

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.     

具有不可控变迁的离散事件系统Petri网控制器的研究

针对基于Petri网建模的离散事件系统的Petri网控制器的设计问题,分析了系统中存在不可控变迁时的情况,并基于局部设计和Petri网简化技术,提出了一种新的控制器设计方法。该方法首先将约束条件分为允许约束和非法约束,并通过矩阵转换方法将非法约束转换为允许约束,然后通过约束矩阵设计出相应的控制器。该方法由于只考虑与约束库所、约束变迁及不可控变迁相关联的局部关联矩阵,降低了矩阵的维数,简化了控制器的设计,避免了死锁。最后,基于两个实例验证了该方法的高效性。     

基于Petri网的离散事件仿真与控制软件的开发及关键技术

针对离散事件系统控制对Petri网软件工具的需求,设计和开发基于Petri网的离散事件仿真与控制软件。通过分析离散事件仿真与控制的要求,确定软件的功能与目标,据此设计软件的体系结构。研究软件开发中的几个关键技术,如控制Petri网的提出及其基本类设计、基于控制Petri网的控制与仿真、Petri网模型的存储与读取、客户/服务器模式软件网络化架构等。开发基于Petri网的离散事件仿真与控制软件,它不仅具有Petri网模型建模与分析功能,还能实现基于Petri网的离散事件系统的网络化控制与仿真。在可重构加工系统试验平台上的应用表明,该软件是有效和实用的。     

Synthesis of feedback control elements for discrete event systems using Petri net models and theory of regions

This paper describes a method for constructing a Petri-net-based controller for a discrete event system (DES) modelled by a Petri net. Assuming that an uncontrolled Petri net model of the DES and a set of forbidden state specifications are given, feedback control elements, i.e. a set of places and related transitions, with initial marking, are computed using the theory of regions, which is a formal synthesis technique for deriving Petri nets from automaton-based models. When feedback control elements are added to the uncontrolled Petri net model, the controlled (closed-loop) Petri net model of the system is obtained. The controlled Petri net model obtained is maximally permissive while guaranteeing that forbidden states do not occur. The proposed method is computationally efficient and does not suffer from the state explosion problem. Two examples are provided to show the applicability of the proposed method.     

永磁同步风力发电机的神经网络自适应内模控制

为了提高永磁同步风力发电机的调速性能,结合自适应内模控制,将神经网络方法用于永磁同步风力发电机调速控制系统,设计了神经网络自适应速度控制器。基于MATLAB的仿真结果证明,神经网络自适应内模控制系统有很强的自适应能力和抗负载扰动能力,控制系统具有良好的静、动态特性。     

衍射光栅刻划机微定位系统控制器设计

针对衍射光栅刻划机开环控制的定位精度不能满足指标要求的问题,在刻划机已有的状态和结构下,设计了微定位系统的控制器。首先,介绍了衍射光栅刻划机,分析了微定位系统及其定位精度指标。然后,运用系统辨识的方法,设计了微定位系统的扫频实验,建立其数学模型。接着,提出了在已有数学模型的基础上,运用实际测量数据和MATLAB/Simulink软件仿真试凑来设计控制器的方法,并设计了满足精度指标要求的控制器。最后,将设计的控制器应用于微定位系统并进行模拟刻划实验,实验结果可知:所设计的微定位系统控制器定位精度基本满足指标要求,其中峰-峰值小于40 nm,RSM值总体略大于2.8 nm。     

基于ARM的开放式数字运动控制器的设计

采用ARM嵌入式微控制器,结合专用电机控制芯片,构建出基于串行总线轴伺服运动控制器的硬件平台。采用了全数字式位置闭环控制,使用模糊PID参数修正方式实现对伺服控制器中电流环和速度环PI控制器参数的自适应修正,通过试验证明该设计获得了理想的控制结果。     

基于电磁耦合无级变速器的混合动力车传动控制

研究基于电磁耦合无级变速器的混合动力传动系统,分析其基本原理和功率流模型,并对电磁耦合无级变速器的变速比控制目标、工作模式和控制策略进行详细研究,同时设计适用的整车传动控制器框架。为了研究混合励磁的动态控制效果,对混合动力汽车在低速大负载和高速工况下进行初步动力性仿真。通过仿真,分析车速跟踪的控制效果、发动机转速跟踪控制效果、电池组荷电状态的变化曲线、电磁耦合无级变速器的转速和转矩、发动机输出功率、电池组输出功率和行驶阻力功率等的变化规律,并得出直流励磁电流和电磁耦合无级变速器的磁链观测值变化规律。