Dynamic Engaging Characteristics of Wet Clutch in Automatic Transmission

Wet clutch is an important shifting component in automatic transmission,and its properties will affect the gear shift performance. By comparing the calculated and test results,the static friction torque model was proved to be capable of describing the real pressure and torque only in the situation of high-energy engagement.Therefore,a dynamic torque model was proposed on basis of hydrodynamic properties between friction surfaces, in which the clutch engagement was divided into three phases for hydrodynamic lubrication, mixed lubrication, and mechanical contact. The proposed dynamic torque model was validated by comparing the calculated and test results. The effects of temperature,pressure,and pressure changing rate of automatic transmission fluid( ATF) on the clutch torque were analyzed. Based on these results,the clutchto-clutch torque control during shifting in automatic transmission was optimized,and as a result,the shifting comfort was significantly improved since the problems such as the fluctuation and sudden drop of the engine rotating speed during shifting were eliminated.

基于ACE与YOLOv5的电力遥感图像检测算法

针对电力遥感图像采集时存在大量浓烟以及数据样本少等问题,提出一种基于对数变换的改进型自动色彩均衡与改进后YOLOv5s模型的遥感图像去雾检测算法,旨在通过提高数据集的图像质量进而提高检测网络的检测精度。构建的改进型自动色彩均衡对电力遥感图像去雾增强,并通过图像质量和特征提取两方面进行了实验数据对比,实验结果表明改进的自动色彩均衡算法优于其它算法。其次,通过YOLOv5s检测算法对增强后的数据集进行训练,引入mosaic数据增强算法,并通过构建ghost卷积模块和NAM注意力模块降低了网络参数、提升了网络检测精度。

OPTIMAL CONTROL APPLIED IN AUTOMATIC CLUTCH ENGAGEMENTS OF VEHICLES

Start-up working condition is the key to the research of optimal engagementof automatic clutch for AMT. In order to guarantee an ideal dynamic performance of the clutchengagement, an optimal controller is designed by considering throttle angle, engine speed, gearratio, vehicle acceleration and road condition. The minimum value principle is also introduced toachieve an optimal dynamic performance of the nonlinear system compromised in friction plate wearand vehicle drive quality. The optimal trajectory of the clutch engagement can be described in theform of explicit and analytical expressions and characterized by the deterministic and accuratecontrol strategy in stead of indeterministic and soft control techniques which need thousands ofexperiments. For validation of the controller, test work is carried out for the automated clutchengagements in a commercial car with an traditional mechanical transmission, a hydraulic actuator, agroup of sensors and a portable computer system. It is shown through experiments that dynamicbehaviors of the clutch engagement operated by the optimal control are more effective and efficientthan those by fuzzy control.

Adaptive Clutch Engaging Process Control for Automatic Mechanical Transmission

Based on detail analysis of clutch engaging process control targets and adaptive demands, a control strategy which is based on speed signal, different from that of based on main clutch displacement signal, is put forward. It considers both jerk and slipping work which are the most commonly used quality evaluating indexes of vehicle starting phase. The adaptive control system and its reference model are discussed profoundly. Taking the adaptability to different starting gears and different road conditions as examples, some proving field test records are shown to illustrate the main clutch adaptive control strategy at starting phase. Proving field test gives acceptable results.

Application of clutch to clutch gear shift technology for a new automatic transmission

For the purpose of engineering development for a new 8-step speed automatic transmission,a simplified dynamic model for this gearbox was established and key parameters which affected the shift quality were analyzed.Aiming at four different shift types,the ideal characteristics of shift clutch and engine control were set up.By using torque estimation method,PI slip control algorithm and engine coordinated control principle,the control model and transmission controller were well developed for three shift phases which included rapid-fill phase,torque phase and inertia phase.The testing environment on the rig and prototype vehicle level was built and the testing results obtained in ultimate condition could verify the accuracy and feasibility of this shift control strategy.The peak jerk during shift process was controlled within ±2 g/s where the smooth gearshift was obtained.The development proposal and algorithm have a high value for engineering application.

Fabrication of automatic switch for AC-DC completely automated measurement system at NIS

A fast automatic AC-DC switch is designed and fabricated mainly by a microcontroller and three double poles single throw reed relays.This new switch is introduced to establish a fully automated system for AC-DC measurements through ACDC transfer standards for the first time at the National Institute for standards(N IS)in Egypt.The implemented circuit of theautomatic AC-DC switch and its protection are presented in details.An AC voltage source is calibrated against DC voltagesource by using the demonstrated automatic switch as an application The calibrated voltage ranges are2V,6V,20V and60V as examples.The uncertainty budget is also evaluated for the calibrated values.

OPTIMAL TORQUE CONTROL STRATEGY FOR PARALLEL HYBRID ELECTRIC VEHICLE WITH AUTOMATIC MECHANICAL TRANSMISSION

In parallel hybrid electrical vehicle （PHEV） equipped with automatic mechanical transmission （AMT）, the driving smoothness and the clutch abrasion are the primary considerations for powertrain control during gearshift and clutch operation. To improve these performance indexes of PHEV, a coordinated control system is proposed through the analyzing of HEV powertrain dynamic characteristics. Using the method of minimum principle, the input torque of transmission is optimized to improve the driving smoothness of vehicle. Using the methods of fuzzy logic and fuzzy-PID, the engaging speed of clutch and the throttle opening of engine are manipulated to ensure the smoothness of clutch engagement and reduce the abrasion of clutch friction plates. The motor provides the difference between the required input torque of transmission and the torque transmitted through clutch plates. Results of simulation and experiments show that the proposed control strategy performs better than the contrastive control system, the smoothness of driving and the abrasion of clutch can be improved simultaneously.

汽车自动变速器换挡控制自动校准算法研究

为改善自动变速器的换挡特性,提出了一种基于模型的自动变速器离合器液压自动校准方法,实现离合器换挡参数的自动调整。该校准方法包括自动变速器仿真模型、车辆仿真分析算法和基于优化过程的自动校准算法,并在优化过程中进行迭代仿真和分析。以通电换挡为研究对象,仿真结果表明无论是通电升挡,还是通电降挡,该方法均能够有效地执行离合器液压曲线的基本映射,通过所提出的校准方法能够缩短实际车辆试验前的校准时间,提高自动变速器开发过程的效率。

Study of Controlling Clutch Engagement for AMT Based on Fuzzy Logic

The control of the clutch engagement for an automatic mechanical transmission in the process of a tracklayer getting to start is studied. The dynamic model of power transmission and automatic clutch system is developed. Using tools of Simulink, the transient characteristics during the vehicle starting, including the jerk and the clutch slip time, are provided here. Based on the analyses of the simulation results and driver’s experiences, a fuzzy controller is designed to control the clutch engagement. Simulation results verify its value.

CMAC与PID的并行控制在火箭炮交流伺服系统中的应用

火箭炮交流伺服系统是复杂的变负载、大功率系统,其控制系统的参数变化大,采用单一的PID控制算法很难取得较高的控制品质和控制精度。根据CMAC控制鲁棒性强和可靠性高,以及PID控制器功能简单、便于使用及在各种不同工作条件下保持较好工作性能的特点,提出了CMAC神经网络与PID结合的复合控制策略。在Matlab中进行计算机仿真,结果表明了该控制策略的有效性和实用性。

一种变速箱离合器自动安装机构的设计

离合器是变速箱的重要核心组件,也生产装配工艺中重要的环节。本文介绍了离合器在变速箱装配生产线上实现自动装配的方法和自动装配机构的设计,该自动装配机构和工业机器人组合应用,利用PLC作为电气控制核心,采集外部信号,通过Profinet总线网络与机器人交互信息,实现对离合器的自动化装配。这个机构设备可以很好的解决离合器在安装时容易磕碰到输入轴齿和油泵斜齿轮的问题。对工厂来说,解决了人工装配中的难点痛点,也节省了成本,提升变速箱的装配质量和效率。从自动装配行业来说,未来发展趋势是向着无人的方向发展,为以后提高变速箱装配线的自动化水平提供参考。

基于改进ACE算法的快速去雾方法

针对传统的自动色彩均衡算法时间复杂度高的问题,提出了一种基于改进的自动色彩均衡(Automatic Color Equalization, ACE)快速去雾算法。算法以ACE算法为基础,引入改进的拉普拉斯金字塔算法,得到一种快速去雾算法。在拉普拉斯金字塔算法上结合雾天图像还原原理,设定像素阈值,减少拉普拉斯子金字塔的层数。在ACE算法上通过缩小像素中心点邻域的大小来减少像素之间的比较次数,并在每层金字塔上应用改进的ACE算法,达到降低运算复杂度的效果。在金字塔重构上根据图像亮度信息来计算待融合图像的权重。实验结果表明,上述算法有效的增强了图像视觉效果,降低了运算复杂度,便于实际应用。

智能双AC/DC变换器供电系统的两种设计方案

针对双AC/DC变换器现有的热备份、冷备份连接方式存在的问题,提出了智能双AC/DC变换器供电系统的两种新的设计方案——数字逻辑控制电路和微控制器控制系统,实现了冷备份电源的自动切换,很好的解决了直流电源持续供电的问题。

ACS-Ⅱ型破乳剂自动控制系统在炼油厂的应用

通过ACS-Ⅱ型破乳剂自动控制系统在炼油厂原油电脱盐装置上的应用,使药剂以原剂形式注入,工艺得到简化,工人劳动强度降低,操作方便、直观、精度高。同时使设备小型化,减少了设备占地面积,节约了电能及药剂量。

双选像素点的局部自适应ACE算法

针对自动色彩均衡(ACE)算法不能很好地保持图像原始色彩信息,并且算法复杂度高较难满足实时性应用的缺点,提出双选像素点的局部自适应ACE算法。将获得的图像变换到YCbCr色彩空间中,有利于保持图像的原始色彩信息,利用亮度图像的梯度信息与图像局部的均值方差信息进行双层像素点选择,降低算法的运算复杂度,采用局部自适应滤波调整ACE算法中的亮度控制函数,增强图像的局部对比度。实验结果表明,与传统的ACE算法相比,色彩恢复多尺度Retinex算法MSRCR的视觉效果更好,运行速度提高约150倍,计算复杂度得到了明显改进。

基于液压系统的自动挡变速器的故障分析与处理

本文阐述了自动变速器液压驻车系统的工作原理,利用CANape软件对双离合器自动变速器由液压驻车系统和液压控制模块引起的常见的故障进行详细分析,并针对故障提出可行的解决措施,为解决自动挡变速器常见故障等问题提供了理论和实践依据。

基于模型预测控制的AMT自动离合器控制研究

离合器控制是影响自动变速器换挡平顺性的重要因素,传统的控制方法难以对自动离合器这种大滞后、非线性系统进行精确的控制。综合考虑将换挡平顺性和发动机稳定运转等因素作为系统约束,以换挡时间最短、滑磨功和冲击度最小作为设计目标,设计了基于模型预测控制(MPC)算法的自动离合器结合控制器。通过仿真和实车试验验证,与模糊逻辑控制算法相比,模型预测控制算法能有效地降低换挡过程中的冲击度和滑磨功,提升了换挡品质。

双离合自动变速器台架路谱试验方法研究

介绍了一种基于双离合变速器的路谱采集及台架试验应用方法,通过前期实车采集路谱数据、转化合成台架路谱测试方法、开展动力总成级的台架路谱测试,对双离合自动变速器质量进行评价。试验结果显示,台架路谱测试工况达成与整车测试基本一致,针对硬件验证可对整车开展有效替代。

自动变速器牙嵌式离合器进挡概率研究与应用

文章以某9挡自动变速器的牙嵌式离合器为研究对象,建立了离合器结合各阶段的动力学模型。根据长短齿设计特征,分别计算无任何齿形接触、长齿接触长齿、长齿接触短齿、长齿接触长齿和长齿接触短齿同时发生四种场景在不同初始速差条件下的进挡概率。考虑随机齿形接触位置的终止速差,计算得到牙嵌式离合器进挡的最优速差,可用于滑行降挡最优进挡策略的制定,提升换挡质量。选取实车滑行五挡降四挡工况,进行进挡概率校验,结果和理论计算概率相符合。

ACE密码算法的积分分析

ACE是国际轻量级密码算法标准化征集竞赛第2轮候选算法之一。该算法具有结构简洁,软硬件实现快、适用于资源受限环境等特点,其安全性备受业界广泛关注。该文引入字传播轨迹新概念,构建了一个传播轨迹的描述模型,并给出一个可以自动化评估分组密码算法抵抗积分攻击能力的方法。基于ACE算法结构特点,将该自动化搜索方法应用于评估ACE算法的安全性。结果表明:ACE置换存在12步的积分区分器,需要的数据复杂度为2^(256),时间复杂度为2^(256)次12步的ACE置换运算,存储复杂度为8 Byte。相比于ACE算法设计者给出的积分区分器,该新区分器的步数提高了4步。