基于遗传算法非线性PID的柴油机共轨压力控制

高压共轨柴油机共轨压力随不同工况的调节能力及其压力的稳定性,从根本上影响着柴油机系统的燃油经济性与排放性能;针对共轨压力的控制,给出了在起动、过渡、正常、停机以及故障等工况下的轨压控制策略,设计了带预控制的积分分离非线性PID控制器,采用遗传算法对PID参数进行了在线自适应整定,实现了在不同柴油机工况下对不同轨压变化的优化控制;台架实验结果表明,在不同工况下采取的控制策略是适用的,采用的积分分离技术能减少控制超调,预控制技术能缩短轨压稳定时间并减少轨压波动,遗传算法对非线性PID控制器参数的在线优化,平均可在柴油机起动后6.7s内完成,所设计的非线性PID控制器可把轨压控制偏差稳定在1.4%以下。     

缸内直喷汽油机的自抗扰轨压跟踪控制器设计

获得期望的共轨压力是保证缸内直喷发动机(GDI)稳定工作和喷油量精确控制的一个重要前提. 本文针对缸内直喷汽油发动机轨压控制问题, 首先通过动力学分析建立了共轨燃油喷射系统的数学模型; 由于系统中存在有较强的非线性和不确定性, 采用基于模型但对模型的精确形式依赖较小的自抗扰控制技术设计轨压跟踪控制器,其中线性扩张状态观测器(ESO) 对系统存在的总扰动和不确定性进行了估计, 非线性误差反馈控制(NLSEF) 则采用反馈补偿实现扰动的抑制. 最后, 通过给定不同的参考轨压对控制器的有效性进行验证, 仿真结果表明控制性能是满意的.     

神经网络PID共轨压力控制方法的研究

采用神经网络实现在复杂工况下柴油共轨压力调节器PID控制系统的参数整定,建立了YN4100QB柴油机共轨压力调节器AMESim仿真模型,利用MATLAB/Simulink设计了柴油机共轨压力调节器控制系统BP神经网络PID仿真模块,在AMESim环境下对共轨压力调节器进行了动态仿真。仿真试验表明,神经网络PID制器具有良好的动态性能和较强的鲁棒性,与传统PID控制相比,大大改善了共轨压力调节器在复杂工况下压力调节的性能。     

基于智能竞标的自适应轨压控制算法

设计了一种应用于高压共轨柴油发动机的轨压控制算法;算法采用组合竞拍机制以解决复合工况下的轨压扰动问题,并设计了一种分段动态标定算法以解决传统PID标定算法计算效率低的问题,此外算法针对柴油发动机特性对PID控制器进行了多项改进以提高算法响应速度和跟随性;最后通过仿真实验对算法进行了验证,实验结果证明本算法对输入转速信号及喷油期望值具有良好的跟随性和响应速度,并且轨压控制较为平稳,其波动幅度不超过1％,基本符合高压共轨柴油发动机正常工作的需要.     

一种高压共轨柴油发动机的轨压控制算法

设计了一种应用于高压共轨柴油发动机的PID轨压控制算法,以解决传统轨压算法控制复杂性和计算效率的问题。本算法简化了处理工况,并针对柴油发动机特性对PID控制器进行了多项改进,并用其统一的处理运行工况下的轨压计算。通过仿真实验对算法进行了验证,实验结果证明本算法对输入发动机信号和轨压期望具有良好的跟随性和运行效率,并且轨压控制较为平稳,其波动幅度不超过1%,基本符合高压共轨柴油发动机正常工作的需要。     

粘度测量直流电机调速系统自适应控制器的建模与仿真

基于旋转法的液体粘度测量需要不同等级稳定的电机旋转速度。采用电流转速双闭环来实现对直流电机调速系统的控制。电流内环使用PI控制,转速外环采用大增益比例控制结合PID控制,PID参数使用模糊逻辑进行自整定,这种控制方式可根据输入偏差大小选择不同控制策略实现转速的自适应快速调节与准确跟踪。在Matlab/Simulink平台上搭建基于这种控制器的仿真模型,对直流电机调速系统进行仿真。仿真结果表明这种系统具有良好的控制性能,这种自适应控制器具有良好的动态响应特性,可以消除稳态误差。     

多模型控制策略在化石燃料发电机组上的应用(英文)

火力发电厂中广泛使用的化石燃料发电机组(FFPU)具有非线性、强耦合、参数随工况变化等复杂特性,依据单个工作点处的线性模型设计的多变量控制策略常常导致控制效果不佳,甚至系统不能稳定运行。针对该问题,本文提出了一种有效的多模型控制策略,以改善FFPU大工况范围运行时的控制性能。首先,通过定义归一化特征值作为系统非线性测度,将FFPU工作运行区间划分成多个局部模型区域,在每个区域用线性模型表征系统特性;随后,根据每个局部区域的线性模型,实施一种基于FFPU特性而设计的包含静态前馈、PD前馈和模糊解耦的混合解耦补偿,进而采用模糊PID结构设计分散控制器;最后,依照电力负载跟随调度策略,模糊加权局部控制器得到全局控制器输出,使得系统在大工况范围运行时平滑切换。为实现该控制策略,采用了双层控制结构:上层为监督控制层,作用是根据负载要求进行设定点调度以及进行局部控制器的模糊切换;下层为直接控制层,实施混合解耦补偿和各回路的模糊PID控制。仿真表明,所提出的控制策略性能良好且实用有效。     

废气再循环–可变几何截面涡轮增压柴油发动机 燃气双环系统建模及协同控制

针对废气再循环(EGR)与可变几何截面涡轮增压(VGT)的柴油发动机,作者联合考虑其燃油动力转速调节回路与气体回路,提出了内外双环稳定动态反馈的控制策略.其中,内环回路是利用Lyapunov函数设计的控制器,控制燃油质量流量来跟踪柴油发动机转速;外环回路则设计EGR–VGT控制器,跟踪气体回路的进排气歧管压力及压气机空气质量流量,并克服了柴油发动机建模中的不稳定零动态问题.同时,研究了气体流量与EGR和VGT阀门开度之间的关系,通过设计流量开度转换模块实现了两者控制的转换.最后,通过专业发动机软件AMESim与仿真软件MATLAB/Simulink的联合仿真试验,验证了该控制策略对柴油发动机燃油动力转速调节与气体回路控制的有效性.     

基于Simulink的气控液压背压阀仿真与设计

在Simulink中建立了气控液压背压阀的仿真模型并对其进行设计,目的在于实现根据气路压力控制液压回路背压的功能,使其能够连结气动与液压控制,在航空航天、能源、动力等领域具有相当的应用空间和价值。在设计过程中采用的控制方法是对背压进行双闭环控制,其中外环利用PID控制调节液压回路背压,内环通过控制无刷直流电动机来调节针阀阀芯位移,并且利用Simulink仿真确定不同给定量对应的PID控制器参数。单片机作为背压阀控制系统的核心,依据各个传感器采集的信号选择PID控制器参数,进而调节电动机转速,实现背压的精确控制。通过测试可以得出结论,该背压阀达到了设计目标,解决了非线性系统的PID控制问题,在气压不同时能够稳定、准确、快速地调节液压回路背压。     

飞机燃油系统地面模拟试验引气箱压力控制

飞机燃油系统地面模拟试验的引气箱压力控制系统是电、液气压控制系统;由于气体的可压缩性及控制过程中气体压力、体积、温度三者之间的变化,系统具有很强的非线性和时变特性;针对系统这些特点,提出了基于模糊自适应PID的控制策略,将模糊控制器响应快、抑制扰动能力强的优点与PID控制器鲁棒性强的特性融为一体;仿真分析表明该方法有效地提高了非线性时变系统的动、静态特性。     

Introduction to the benchmark challenge on common rail pressure control of gasoline direct injection engines

As one of the most important actuators for gasoline direct injection technology, common rail systems provide the requested rail pressure for fuel injection. Special system characteristics, such as coupled discrete-continuous dynamic in the common rail system, limited measurable states, and time-varying engine operating conditions, impel the combination of advanced methods to obtain the desired injection pressure. Therefore, reducing the pressure fluctuation and satisfying engineering implementation have become noteworthy issues for rail pressure control (RPC) systems. In this study, the benchmark problem and the design specification of RPC proposed by 2018 IFAC E-CoSM Committee are introduced. Moreover, a common rail system model is provided to the challengers, and a traditional PI control is applied to show the problem behaviors. Finally, intermediate results of the challengers are summarized briefly.     

Rail pressure controller design of GDI basing on predictive functional control

Gasoline direct injection (GDI) is a pivotal technique for a highly efficient engine. However, how to maintain a stable rail pressure which offers good fuel economy and low emissions, is still a challengeable work. In this paper, a rail pressure controller is designed basing on predictive functional control (PFC), a model predictive control (MPC) method, to surmount the nonlinearity and discontinuity brought by the common rail pressure system (CRPS). A control-oriented piecewise linear model is presented to simplify the CRPS. The simulation results on a benchmark show that rail pressure tracks the setpoint accurately even with some perturbations. Profiting from the conciseness of PFC algorithm, the controller can compute the online solution in a short time, which makes it possible to realize the strategy on a fast response system.     

蓄压式共轨燃油喷射系统的计算机仿真

该文介绍了共轨燃油喷射系统仿真模型和喷油过程的计算机仿真。在共轨燃油喷射系统中，燃油是由一个高压蓄压轨分配到各个喷油器中去的，而蓄压轨是由一个高压泵来填充的。高压蓄压轨中的压力、各个缸喷油的开始和结束都是电控的。基于共轨燃油喷射系统工作原理，该文主要涉及高压泵、调压阀、限流阀和喷油器的建模、整个系统回路的液力特性分析，最后实现共轨燃油喷射系统功能和过程的计算机仿真。仿真方法和仿真结果对燃油喷射系统的研究和开发提供了一个有效的工具。     

国内外柴油机电控喷油技术的发展现状及前景

本文首先阐述柴油机电控喷油技术国内外发展的背景和现状,接着介绍柴油机电控喷油系统的基本组成和控制原理,简要介绍了其分类。根据柴油机电控系统的组成和控制原理以及国内外现状,针对国内外现有柴油机电控技术存在的几个问题,探讨将来柴油机电控技术的发展方向和前景。并综合得出未来最具前景的系统为电控高压共轨式喷油系统。     

Terminal sliding mode control of rail pressure for gasoline direct injection engines

The desired fuel rail pressure is a crucial factor for guaranteeing the gasoline direct injection (GDI) engine to work stably. In order to solve the rail pressure control problem, the detailed nonlinear model of GDI is derived and reasonable simplification of this model is carried out for the following controller design. Terminal sliding mode control strategy is proposed to design the rail pressure controller with Lyapunov stability. The designed approach with the fast terminal sliding mode surface makes the system have the capacity of global fast convergence and achieves precise tracking control. To demonstrate the validity of the designed control method, simulations are conducted by tracking the different reference rail pressures. Results show that the designed controller tracks the given reference accurately and has strong robustness.     

一种基于多次喷射的高压共轨喷油控制算法

设计了一种应用于柴油机高压共轨系统的喷油控制算法.该算法针对现有的多次喷射技术进行了改进,细化了喷油次数以提高燃油燃烧效率,采用并发控制方式提高算法执行速度.该算法首先通过基于优先级和区段划分的多次喷射协调方法将喷油过程划分为5次独立的喷射过程,然后分别对每次喷射进行油量计算、分解、正时转换等控制计算,其中分解运算过程采用了并发控制算法以提高运算效率,最终将喷油量转换为脉冲序列以操作喷油器喷油.通过理论分析与仿真实验对该算法的功能和性能进行了验证.     

A model-based gain scheduling approach for controlling the common-rail system for GDI engines

The progressive reduction in vehicle emission requirements have forced the automotive industry to invest in research for developing alternative and more efficient control strategies. All control features and resources are permanently active in an electronic control unit (ECU), ensuring the best performance with respect to emissions, fuel economy, driveability and diagnostics, independently from engine working point. In this article, a considerable step forward has been achieved by the common-rail technology which has made possible to vary the injection pressure over the entire engine speed range. As a consequence, the injection of a fixed amount of fuel is more precise and multiple injections in a combustion cycle can be made. In this article, a novel gain scheduling pressure controller for gasoline direct injection (GDI) engine is designed to stabilise the mean fuel pressure into the rail and to track demanded pressure trajectories. By exploiting a simple control-oriented model describing the mean pressure dynamics in the rail, the control structure turns to be simple enough to be effectively implemented in commercial ECUs. Experimental results in a wide range of operating points confirm the effectiveness of the proposed control method to tame efficiently the mean value pressure dynamics of the plant showing a good accuracy and robustness with respect to unavoidable parameters uncertainties, unmodelled dynamics, and hidden coupling terms.     

Control of the common rail pressure in gasoline engines through an extended state observer based MPC

In this paper, a model predictive control (MPC) solution, assisted by extended state observer (ESO), is proposed for the common rail pressure control in gasoline engines. The rail pressure dynamic, nonlinear with large uncertainty, is modeled as a simple first order system. The discrepancy of the model from the real plant is lumped as ``total disturbance'', to be estimated in real-time by ESO and then mitigated in the nonlinear MPC, assuming the total disturbance does not change in the prediction horizon. The nonlinear MPC problem is solved using the Newton/generalized minimum residual (GMRES) algorithm. The proposed ESO-MPC solution, is compared with the conventional proportional-integral-differential (PID) controller, based on the high-fidelity model provided in the benchmark problem in IFAC-E-CoSM. Results show the following benefits from using ESO-MPC relative to PID (benchmark): 1) the disturbance rejection capability to fuel inject pulse step is improved by 12% in terms of recovery time; 2) the transient response of rail pressure is improved by 5% in terms of the integrated absolute tracking error; and 3) the robustness is improved without need for gain scheduling, which is required in PID. Additionally, increasing the bandwidth of ESO allows reducing the complexity of the model implemented in MPC, while maintaining the disturbance rejection performance at the cost of high noise-sensitivity. Therefore, the ESO-MPC combination offers a simpler and more practical solution for common rail pressure control, relative to the standard MPC, which is consistent with the findings in simulation.     

Hybrid modelling and control of the common rail injection system

We present an industrial case study in automotive control of significant complexity: the new common-rail fuel-injection system for Diesel engines under development at Magneti Marelli Powertrain. In this system, an inlet metering valve, inserted before the high pressure (HP) pump, regulates the fuel flow that supplies the common rail according to the engine operating point (e.g., engine speed and desired torque). The standard approach in automotive control based on a mean-value model for the plant does not provide a satisfactory solution as the discrete-continuous interactions in the fuel injection system, due to the slow time-varying frequency of the HP pump cycles and the fast sampling frequency of sensing and actuation, play a fundamental role. We present a design approach based on a hybrid model of the Magneti Marelli Powertrain common-rail fuel-injection system for four-cylinder multi-jet engines and a hybrid approach to the design of a rail pressure controller. The hybrid controller performs significantly better when compared with the classical mean-value based approach.