Minimum energy control of an s-cvt equipped power transmission

This article deals with a minimum energy control law of S-CVT connected to a dc motor. The S-CVT can smoothly transit between the forward, neutral, and reverse states without any brakes or clutches, and its compact and simple design and its relatively simple control make it particularly effective for mechanical systems in which excessively large torques are not required. And such an S-CVT equipped power transmission has the advantage of being able to operate the power sources in their regions of maximum efficiency, thereby improving the energy efficiency of the transmission system. The S-CVT was intended to primarily for use in small power capacity transmissions, thus a dc motor was considered here as the power source. We first review the structure and operating principles of the S-CVT. including experimental results of its performance. And then we describe a minimum energy control law of S-CVT connected to a dc motor. To do this, we describe the results of an analysis of the dynamics of an S-CVT equipped power transmission and the power efficiency of a DC motor. The minimum energy control design is carried out via B-spline parameterization. And we show numerical results obtained from simulations illustrate the validity of our minimum energy control design, benchmarked with a computed torque control algorithm for S-CVT.     

Side slip angle based control threshold of vehicle stability control system

Vehicle Stability Control (VSC) system prevents vehicle from spinning or drifting out mainly by braking intervention. Although a control threshold of conventional VSC is designed by vehicle characteristics and centered on average drivers, it can be a redundancy to expert drivers in critical driving conditions. In this study, a manual adaptation of VSC is investigated by changing the control threshold. A control threshold can be determined by phase plane analysis of side slip angle and angular velocity which is established with various vehicle speeds and steering angles. Since vehicle side slip angle is impossible to be obtained by commercially available sensors, a side slip angle is designed and evaluated with test results. By using the estimated value, phase plane analysis is applied to determine control threshold. To evaluate an effect of control threshold, we applied a 23-DOF vehicle nonlinear model with a vehicle planar motion model based sliding controller. Controller gains are tuned as the control threshold changed. A VSC with various control thresholds makes VSC more flexible with respect to individual driver characteristics.     

轿车用自动变速箱的发展动态

随着对换档品质。燃油经济性等方面要求的不断提高,自动变速箱在轿车上的装车率也提高。目前自动变速箱的主流形式是流力机械式。最新的发展方向集中在以下几方面,变矩器的高效率化、多档位化、变矩器没离合器的打滑控制、换档点控制的智能化、换档过渡过程的高品质化和保留手动模式。本文详细讨论了上述各项技术的发展背景、核心技术和发展方向等问题。     

Modeling and control of an electronic-vacuum booster for vehicle cruise control

A mathematical model and control laws for an Electronic-Vacuum Booster (EVB) For application to vehicle cruise control will be presented. Also this paper includes performance test result of EVB and vehicle cruise control experiments. The pressure difference between the vacuum chamber and the apply chamber is controlled by a PWM-solenoid-valve. Since the pressure at the vacuum chamber is identical to that of the engine intake manifold, the output of the electronic-vacuum booster is sensitive to engine speed. The performance characteristics of the electronic-vacuum booster have been investigated via computer simulations and vehicle tests. The mathematical model of the electronic-vacuum booster developed in this study and a two-state dynamic engine model have been used in the simulations. It has been shown by simulations and vehicle tests that the EVB-cruise control system can provide a vehicle with good distance control performance in both high speed and low speed stop and go driving situations.     

工程车辆三参数模糊换挡策略的研究

针对工程车辆自动换挡的复杂性和难以建立准确的数学模型的特点,提出了由PLC(可编程序控制器)、HMI(人机界面)及相关的传感器组成的模糊换挡自动控制系统。利用驾驶员的实际驾驶经验形成模糊控制规则,将模糊控制规则存入PLC的存储器中,实现了工程车辆自动换挡。车辆传动试验结果表明控制系统抗干扰能力强、实现简单、换挡品质理想。     

线控转向车辆转向控制策略研究

建立了线控转向系统的数学模型,对前轮转角采用基于理想变传动比的前馈控制和期望横摆角速度反馈控制的动态校正控制算法,从而确定合适的前轮转角,实现前轮主动转向,在一定程度上减轻驾驶员负担。通过对两种附着系数路面进行仿真研究,可以得出采用该控制策略可以缩短车辆的反应时间,减小质心侧偏角稳态值及超调量,使线控转向车辆转向更加平稳,提高抗干扰性,改善车辆的操纵稳定性。     

基于制动时间间隔的ABS控制策略研究

制动强度大小是影响汽车制动安全性的重要因素.通过对制动过程的分析与仿真,提出了一种基于制动时间间隔为控制参数的ABS控制策略.制动过程中,通过改变制动力作用的时间间隔,使制动力的平均值变化.适应不同路面对制动强度的要求,达到防止车轮抱死,提高汽车制动时车辆的稳定性和操纵性的目的.     

汽车ABS滑移率的模糊滑模控制研究

汽车防抱死系统(ABS)是汽车制动过程中的一项基本安全措施,滑移率控制是汽车防抱死控制的重要部分。汽车制动时路况时时变化,汽车滑移率的动力学模型是一个时变、非线性、不确定系统。针对这一特点,将滑模控制运动到汽车防抱死制动控制中,设计了汽车滑移率的等效滑模控制器。为了消除滑模控制切换项带来的抖振,使切换控制项在保证鲁棒性能的同时尽可能小,利用模糊规则,对切换项进行模糊化,建立基于模糊切换控制的等效滑模控制器。仿真结果表明,滑模控制方法具有很好的鲁棒性能,加入模糊规则的等效滑模方法能很好的消除抖振现象。     

Development of TCS slip control logic based on engine throttle control

Slip control systems are used to prevent wheel slipping and to improve acceleration performance, stability and steerability on slippery roads through the engine torque and/or brake torque control. This paper mainly deals with the engine control algorithm via adjustment of the engine throttle angle. The slip control algorithm developed in this research includes a control gain scheduling part and a road estimating part to enhance control performance. Various actual vehicle tests have been carried out on low friction roads in order to verify the developed slip control algorithm. The test results show that the controlled vehicle is superior to the non-controlled vehicle in acceleration performance and stability.     

大型设备吊装装置自动控制系统的开发及应用

本文介绍了一种新型吊装装置及其电气控制系统的有关控制方法,给出了控制有理及系统实施方案;并通过实际工程应用,探讨今后的发展方向。     

PROFIBUS总线在污水处理自控系统中的应用

以西门子PLC S7为例讨论了PLC和现场总线技术，着重分析了其基本特性和相关产品在污水处理自动化控制系统中的应用。     

Lateral vehicle control based on active flight control technology

In this paper, a lateral vehicle control using the concept of control configured vehicle (CCV) is presented. The control objectives for the lateral dynamics of a vehicle include the ability to follow a chosen variable without significant motion change in other specified variables. The analysis techniques for decoupling of the aircraft motions are utilized to develop vehicle lateral control with advanced mode. Vehicle lateral dynamic is determined to have the steering input and control torque input. The additional vehicle modes are also defined to using CCV concept. We use right eigenstructure assignment techniques and command generator tracker to design a control law for an lateral vehicle dynamics. The desired eigenvectors are chosen to achieve the desired decoupling (i.e., lateral direction speed and yaw rate). The command generator tracker is used to ensure steady-state tracking of the driver’s command. Finally, the developed design is utilized by using the lateral vehicle dynamic with four wheel.     

双离合器自动变速器控制系统研究

在分析双离合器自动变速器结构的基础上,对该型变速箱的核心控制系统,包括双离合器自动变速器的转速测量、挡位测量、离合器压力测量以及换挡控制系统等关键技术进行了深入的研究,结合车辆的动力学特性,从理论与试验两方面分析了车辆起步过程中的关键要素.实践表明,对双离合器自动变速器的研制与开发具有指导意义.     

汽车自动挡变速箱换挡离合器装配系统的研发

根据汽车自动变速箱换挡离合器的结构和工艺特点,及生产信息化、网络化和多品种共线柔性化生产的要求,针对汽车自动变速箱换挡离合器的装配和检测,开发出一种具有环形结构的装配系统,并介绍了系统的功能和组成,探讨了该系统的控制方法。该系统已经进入实际应用,可较好地完成换挡离合器的装配和性能检测以及测试后的数据参数存储和分析。     

Regenerative braking control strategy in mild hybrid electric vehicles equipped with automatic manual transmission

The actual regenerative braking force of an integrated starter/generator (ISG), which is varied with desired braking deceleration and vehicle speed, is calculated based on an analysis of the required deceleration, maximum braking force of ISG, engine braking force and state of charge (SOC) of battery. Braking force distribution strategies are presented according to the actual regenerative braking force of ISG. To recover the vehicle’s kinetic energy maximally, braking shift rules for a mild hybrid electric vehicle (HEV) equipped with automatic manual transmission (AMT) are brought forward and effects of transmission ratios are considered. A test-bed is built up and regenerative braking tests are carried out. The results show that power recovered by the braking shift rules is more than that recovered by the normal braking control rules. __________ Translated from Chinese Journal of Mechanical Engineering, 2006, 42(10): 156–160 [译自: 机械工程学报]     

电控自动变速器模糊换档策略研究

传统的方法对道路环境的识别主要是对道路坡度的识别.识别方法一般采用传感器,而这些传感器的成本高,精度低;至于路面状况目前尚难以识别.据此,提出了一种改进的道路阻力识别方法,即通过识别能够综合反映道路坡度角和路面滚动阻力状况的道路综合阻尼率,并利用识别结果采用模糊逻辑技术对二参数换档规律进行修正,从而能在不同的道路环境下采用不同的换挡策略,有效地保证了车辆的动力性,避免了循环换挡的问题,提高了车辆行驶的平顺性.该方法具有计算简单,识别结果准确的特点,是一种实际可应用的有效控制方法.     

A joystick driving control algorithm with a longitudinal collision avoidance scheme for an electric vehicle

In this paper, we develop a joystick manual driving algorithm for an electric vehicle called Cycab. Cycab is developed as a public transportation vehicle, which can be driven either by a manual joystick or an automated driving mode. The vehicle uses six motors for driving four wheels, and front/rear steerings. Cycab utilizes one industrial PC with a real time Linux kernel and four Motorola MPC555 micro controllers, and a CAN network for the communication among the five processors. The developed algorithm consists of two automatic vehicle speed control algorithms for normal and emergency situations that override the driver’s joystick command and an open loop torque distribution algorithm for the traction motors. In this study, the algorithm is developed using SynDEx, which is a system level CAD software dedicated to rapid prototyping and optimizing the implementation of real-time embedded applications on distributed architectures. The experimental results verify the usefulness of the two automatic vehicle control algorithms.     

面向状态的车间控制策略研究

当前的生产计划和控制系统较好地解决了企业中期的物料需求计划与能力需求计划问题,而车间以下层次的生产作业计划与控制是其薄弱环节。这里通过对现代车间生产活动控制的功能、目标和现代车间制造系统基本特征的考察、分析,揭示了现代车间控制的根本矛盾,提出了面向状态的车间控制策略和方法并进行了应用研究。     

Estimation of turbine torque using an adaptive nonlinear observer for closed-loop control of vehicle automatic transmissions

This paper presents an adaptive sliding observer-based method for the estimation of turbine torque. The estimations of turbine torque can be used in the closed-loop control of vehicle power train for better shift quality. A sliding observer structure including saturation functions and boundary layers is applied to adapt torque converter parameters. The proposed method has been investigated via simulation and laboratory experimental studies. It has been shown via simulation and experiments that the proposed methodology is promising for the estimations of turbine torque since it uses only inexpensive angular velocity measurements and is not sensitive to parametric uncertainties.     

Friction coefficient, torque estimation, smooth shift control law for an automatic power transmission

For shift quality improvement, torque sensors are currently too expensive to be used on production vehicles. To achieve smooth acceleration shift, the reference trajectory of the clutch slip speed for accomplishing the shift process within a designated shift completion time and its relationship with the clutch actuating torque were suggested by Jeong and Lee (1999). In order to facilitate the proposed algorithm, nonlinear estimators for necessary information such as the axle shaft torque, clutch friction and turbine torque were designed using only speed sensors. Accounting for the modeling error, a control law for this indirect smooth shift was proposed based on the above mentioned suggestions. Simulation results of the proposed estimators and shift controller were presented and further considerations for practical applications are discussed.