膜片弹簧离合器起步规律研究及仿真分析

利用AMT传动系统数学模型,得出了AMT传动系统的运动微分方程.基于长安铃木儿JL47401发动机,对膜片弹簧离合器起步性能的评价指标冲击度和滑磨功进行了计算和分析,采用了发动机局部恒转速接合的控制策略,通过模糊控制算法,对离合器的接合量和接合速度进行了计算,并基于Matlab的Simulink工具对离合器正常起步和急起步两种工况进行了计算机仿真分析.     

混合迭代学习法在发动机怠速稳速控制中的应用

发动机怠速工况作为发动机主要工况之一,是典型的非线性、滞后性、多变量时变系统,很难建立其准确的数学模型,控制系统的设计也非常复杂。应用传统的PID控制策略,结合比例积分的混合迭代学习控制,介绍了混合迭代学习控制原理并应用在发动机状态变量模型下的怠速控制。在Simulink中建立仿真模型验证该方法的控制效果。结果表明,使用该控制法的发动机状态变量模型有更快的收敛速度、更小的绝对偏差和调节时间,跟踪期望输出用时少,保持怠速转速快速稳定在期望值,性能表现更优。     

大功率天然气发动机怠速控制策略研究

为提高大功率天然气发动机怠速时的稳态和动态效果,以V模式为研究手段,基于一款六缸天然气多点电喷发动机,实现了发动机怠速控制策。首先针对不同的怠速工况设计了不同的目标怠速转速值的计算,并根据发动机特性确定了PI控制模式。利用目标怠速转速和瞬时转速的差值确定不同PI控制参数,通过PI控制调节电子节气门的开度,从而实现对发动机怠速转速的控制。然后根据实际发动机参数搭建了发动机MATLAB/SIMULINK仿真模型,用于对怠速控制策略进行软件在环仿真测试以及PI控制参数预标定。最后在天然气发动机试验台架上对控制策略进行了进一步的试验和标定。试验结果表明：该怠速控制策略,可让发动机转速响应时间控制在1秒左右,转速稳定时间在2秒左右,发动机转速稳态误差控制在±5rpm范围之内,实现了对怠速的良好稳定控制。     

转速及活塞行程对气动发动机性能的影响

根据已建立的气动发动机数学模型,利用Simulink软件对某额定参数的气动发动机在不同转速和不同活塞行程下的工作特性进行了仿真计算,分析了转速和活塞行程对缸内气体温度、缸内气体压力、缸内气体质量及输出扭矩的影响。研究结果表明,气动发动机在转速越低时输出扭矩越大,在活塞行程越大时输出扭矩越大。研究结果为气动发动机的设计和性能改善提供了一定的依据。     

汽车传动系统平顺性驾驶品质控制

汽车驾驶性能是现代汽车的主要性能之一,与汽车动力性、乘员舒适性有很大关系.发动机、变速器的扭矩输出,离合器的分离接合过程等对汽车平顺性都有很大影响.本文介绍了汽车传动系统各组成部分工作原理及其动力学模型,并对影响汽车平顺性的起步控制、换挡控制、急加减速控制、发动机启停控制和间隙补偿控制及其控制算法进行了详细阐述.最后总结了汽车传动系统及其控制策略并介绍近段时间内汽车的研究热点,包括汽车电动化所引起的协调控制问题及智能化对驾驶性能控制的影响等.     

PHEV由纯电动向混合驱动模式切换协调控制设计

针对并联混合动力汽车模式切换过程中动力中断和扭矩波动对车辆驾驶性能的影响,提出一种由纯电动向混合驱动模式切换的协调控制方法.首先,根据切换过程动力学分析及控制目标,将该过程分为离合器接合前后两部分.然后,对前者设计干扰观测器估计并补偿扭矩干扰和模型不确定性,提出基于干扰补偿的协调控制策略,以消除干扰,实现发动机的快速起动、同步;对后者引入发动机扭矩延迟变量,并利用电机扭矩补偿发动机扭矩误差,设计基于电机补偿的扭矩切换协调控制策略,实现平滑切换.仿真结果表明,该控制策略与传统控制方法相比,冲击度降低50.5%,有效减小了扭矩波动,确保了模式切换的平顺性,提高了驾驶性能.     

基于控制器切换的涡扇发动机转速调节及安全保护

本文通过多个控制器间的切换改善了航空发动机加速过程的动态性能,并在转速过高时加以保护。首先,根据航空发动机控制系统模型利用区域极点配置方法对于每个子系统设计一个H∞输出跟踪控制器,并且设计滞后切换规则,使发动机高压转子转速既能快速跟踪参考加速曲线又能保证较小超调,同时由于滞后切换规则的存在避免频繁切换造成的执行机构不必要的损耗;然后设计安全保护控制器及事件触发的切换机制,在高压转子转速过高时保护转速使其不超过最高转速边界,保证飞行安全;最后通过数例仿真验证了本文方法的有效性。     

船舶电站柴油发电机组H2/H∞控制器的研究

船舶电力系统的稳定性主要取决于船舶电站柴油发电机组转速和电压的响应特性,转速和电压相互作用,对两者进行综合控制非常必要。本文将混合H_2/H_∞控制理论应用于柴油机调速系统的设计,将柴油机调速系统的性能要求转化为标准混合H_2/H_∞控制问题。计算机仿真结果表明,利用线性矩阵不等式(LMI)方法所设计的混合H_2/H_∞调速器能在考虑模型不确定性的情况下,有效地提高系统的动态精确度和抑制扰动的能力,解决了转速和电压的综合控制问题,改善了船舶电力系统的稳定性。     

车辆机械式离合器SVM故障检测方法仿真

汽车发动机在正常运转时，踏下离合器难以挂挡，说明此时机械式离合器已经出现故障，但是具体故障类型无法快速识别。为保证发动机与传动装置平稳接合和分离，提出基于SVM(Support Vector Machine,支持向量机)的车辆机械式离合器故障检测方法。该方法首先依据离合器结构分析离合器膜片弹簧负荷以及离合器系统相关动力方程。根据离合器的微分运动方程提取离合器故障特征，建立离合器故障检测模型。根据模型的优化结果，获取模型最佳输出值，实现汽车离合器故障类型的识别。实验结果表明，研究方法应用下测得的离合器的负载转矩、转速、电角速度与实际数值一致，且通过电机电流的异常输出能够快速判断离合器是否已经发生故障。以上测试结果说明该方法的可应用性较强。     

汽油发动机怠速控制系统研究

随着人们生活质量的不断提高,汽车用电设备日益增多,都对汽车发动机怠速工况的变速动力平稳性和节能环保性提出了更高的要求。基于以上背景,设计模糊自适应PID控制算法作为汽油发动机怠速工况主要控制策略,仿真结果表明怠速控制系统汽油发动机转速调节超调量小,响应时间短,抗干扰(负载)能力好,排放小,达到了汽油发动机怠速工况较理想的控制效果。     

NARMAX modelling and robust control of internal combustion engines

Detailed in this paper is a SISO non-linear modelling and robust controller design methodology experimentally verified on an internal combustion engine. The methodology begins with the identification of a NARMAX model that captures the non-linear dynamics relating the input to the output of a system. This model is converted to a describing function representation for the purpose of robust feedback controller design. The ideology for the describing function recovery is developed in the form of an algorithm which can be extended to other NARMAX model structures not considered here. The controller design is executed in the frequency domain where the output performance specification is |y(t)|≤β?t>0 and the actuator saturation constraint is |u(t)|≤K?t>0. For the engine idle speed control application of this study, a SISO NARMAX model of the engine is developed between the by-pass idle air valve (BPAV) and engine speed. The performance objective for the controller design is the time domain tolerance of |Δ rpm| ≤ 100 rpm on idle speed perturbations despite a non-measurable 20 N m external torque disturbance. The controller is validated through numerical simulations as well as experimental verification.     

ROBUST CONTROLLER DESIGN AND EXPERIMENTAL VERIFICATION OF I.C. ENGINE SPEED CONTROL

Presented in this paper is the robust idle speed control of a Ford 4⋅6 L V-8 fuel injected engine. The goal of this investigation is to design a robust feedback controller that maintains the idle speed within a 150 rpm tolerance about 600 rpm despite a 20 Nm step torque disturbance delivered by the power steering pump. The controlled input is the by-pass air valve which is subjected to an output saturation constraint. Issues complicating the controller design include the nonlinear nature of the engine dynamics, the induction-to-power delay of the manifold filling dynamics, and the saturation constraint of the by-pass air valve. An experimental verification of the proposed controller is included. © 1997 by John Wiley & Sons, Ltd.     

基于虚拟仪器的电子节气门数据测试系统开发

发动机电子控制节气门系统包括电控单元、直流电机、减速齿轮、驱动电路等。与传统的节气门控制方法不同,电子节气门系统中节气门在任何工况下都直接由电机驱动。电控单元可根据车辆信息和发动机工况的变化而随时配制一个理想的混合气。这种理想的混合气,可同时满足发动机的动力性、经济性要求,并减少有害物物的排放,具有良好的怠速、加速、减速等工况的过渡性能。开发一套基于虚拟仪器的电子节气门数据测试系统,对国外先进发动机的电子节气门控制系统控制策略进行研究,对科研和教学都有重要的意义。     

Delay-dependent guaranteed cost control for state-delayed system with disturbance and its application to engine idle speed control

This paper proposes a delay-dependent guaranteed cost control scheme for engine idle speed control （ISC） with induction-to-torque delay and external load disturbance. An augmented linearization model of engine at idle speed operating mode was developed based on physical principle and experiment data. To provide a compromise between disturbance rejection and other performance requirements of ISC, a multi-objective cost function upper bound was given, which can help us to take into account the fuel economy and disturbance rejection performance together in ISC. Poles constraint was added to the closed-loop system to guarantee convergence rates of state. The whole optimization solution to ISC can be solved under the framework of LMI. A commercial engine model was utilized to assess the performance of the controller. Simulation results on this model show us that designed controller can achieve desired performance.     

Application of adaptive control to the fluctuation of engine speed at idle

Idle speed control in a fuel-injection engine system has focused on controlling long-term averages of engine speed, but short-term fluctuations of engine speed have been neglected. The torque differences among cylinders influence the idle stability and cause vibration of the vehicle. In this paper, we introduce two intelligent control systems to reduce the fluctuations of engine speed at idle, an evolutionary computing control based on genetic algorithms and a stochastic control based on Alopex algorithm. We first estimate the torque differences among the cylinders by observing an engine cycle of crankshaft angular speed. Then the uniformity level over the engine speed is fedback into the control system. It manipulates spark ignition timings to suppress unbalanced combustions among the cylinders. We test the two adaptive approaches with simulation of a nonlinear engine model, and compare their performances.     

A neural network model-based observer for idle speed control of ignition in SI engine

The paper presents an algorithm of idle speed stabilization in the spark ignition automotive engine by means of spark advance control. The algorithm is based on a well-known approach of a model-based adaptive control and uses artificial neural networks. The control algorithm is based on a neural network model observer of the additional effective torque. The additional load is estimated as difference between effective torque, estimated by the neural network observer, and brake torque, estimated on the basis of a linear quadratic model. In that case the additional load is understood as the sum of the alternator brake torque (additional load form electric car equipments) and the momentary and/or permanent changes of the engine’s characteristics.On the basis of estimated values of the additional load, the required value of angular acceleration is determined to make the engine return to the specified speed. This acceleration is achieved by adjusting the spark advance. The required value of spark advance is estimated by means of a neural network model converse to that of the effective torque.The algorithm was experimentally compared with PID and adaptive algorithms in the same test bed. The tests were conducted under sudden change of external load. The proposed algorithm proved to be more effective in terms of control error.     

Robust control and estimation of clutch-to-clutch shifts

Clutch-to-clutch shifts are ubiquitous in automatic transmissions, motivating the need for formal and robust methods for controlling these shifts. Limited sensing in production transmissions poses a severe hurdle for feedback control of these gearshifts. In the current study, nonlinear estimation methods are developed to compensate for limited sensing, and enable model-based closed loop control of the torque and inertia phases of shifts by manipulation of clutch pressures. During the torque phase, the offgoing clutch is controlled to emulate a one-way clutch, which ensures smooth coordination of the two clutches and reduced overall variation in the output shaft torque during the gearshift. During the inertia phase, the oncoming clutch is controlled to ensure smooth engagement at lock-up, resulting in reduction of shock and subsequent driveline oscillations. Controller performance is evaluated through numerical simulation of the proposed observer based controller on an experimentally validated high order model of a stepped production automatic transmission. The results show that shift control objectives were met by the proposed estimation and control strategy in the presence of appreciable model uncertainty and speed sensor noise, thus validating the robustness and practical effectiveness of the controller. Also, the proposed model-based controller was shown to be effective in controlling gearshifts at different power-levels (at different throttle openings), which establishes effectiveness of the same over a wide range of operating conditions.     

基于T-S模糊模型的非线性网络化控制系统H∞鲁棒容错控制

针对一类具有参数不确定的非线性网络化控制系统,同时考虑网络延时和丢包的影响,基于T-S模糊模型建模,通过构造Lyapunov-Krasovskii泛函,推证出了确保非线性网络化控制系统在执行器或传感器发生失效故障时具有H_∞鲁棒完整性的时滞依赖充分条件,并以求解线性或非线性矩阵不等式的方式给出了控制器的设计方法.最后,仿真算例验证了所提方法的可行性和有效性.     

Development Of Cvt Control System And Its Use For Fuel‐Efficient Operation Of Engine

Continuously variable transmission (CVT) provides an automobile with the ability to change the gear ratio continuously, which can then improve not only ride quality such as acceleration performance but also fuel‐efficiency. However, to take advantage of the ability, a control system that can precisely control the gear ratio is required. This paper proposes such a control system for a belt‐driven CVT system. For controller design, first the CVT system is modeled by analytical and experimental approaches. The resultant static and dynamic characteristics provide a nonlinear first‐order model with an uncertain time constant and time delay. The nonlinear steady‐state gain is adjusted to one by a gain‐scheduled pre‐compensator. Thereby the plant model becomes a linear first‐order lag system with a dead time. The next step is controller design using the plant model. To guarantee stability and control performance against the parameter variation and time delay, the μ‐synthesis, a robust control method, is employed for feedback control. In addition, a feedforward controller is incorporated into the feedback control system to obtain better output response. The feedforward controller is given by a combination of the inverse system of the plant and a reference model that gives desired output response. As a result, the control system becomes a two‐degree‐of‐freedom control system. To evaluate the performance of the control system and its effectiveness on the fuel‐efficiency, computer simulation and driving tests were conducted. The simulation and experiment results prove that the proposed control system can make the gear ratio track a reference output quickly and precisely in the presence of the uncertainties. The results also show that the control system improves fuel‐efficiency by changing the gear ratio so that the engine torque and its revolution speed can satisfy optimum‐efficiency operating condition.