STUDY ON CONTROL STRATEGY OF CLUTCH STARTING FOR CAR WITH A METAL PUSHING BELT-PLANETARY GEAR CONTINUOUSLY VARIABLE TRANSMISSION SYSTEM

The automatic control of clutch starting in car with a metal pushingbelt-planetary gear continuously variable transmission (CVT) is a complex problem. A suited controlstrategy is required to realize quick and smooth start. A simulation state space equation isestablished on clutch staring control of a car with CVT by bond graph theory. According to the fuzzycontrol method with the expert system, a fuzzy control system of car starting process to weaken thejerk motion is introduced. The simulation results indicate that the jerk motion of clutch startingis below 10 m/s^3.

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.

Dynamic Simulation and Valve Structure Optimization of an Electro-Hydraulic Clutch Shift Control System in an Automatic Transmission

The electro-hydraulic clutch control system controls the transferred torque of gear-shifting clutches in clutch-to-clutch transmissions. A nonlinear dynamic model of an electro-hydraulic clutch shift control system is presented. The mechanical and fluid subsystems of all valves are investigated, including their interactions. Model validation of the electro-hydraulic valve system is performed by comparing the simulated and measured pressure curves. The dynamic characteristics of the electro-hydraulic clutch shift control system with different supply pressures and different fluid temperatures are simulated and evaluated. It is found that pipes which are often ignored between the electro-hydraulic valve system and the clutch piston,have strong influence on clutch piston chamber pressures. In order to satisfy the required time and reduce the fluctuation of the clutch piston chamber pressures,the orifices' diameters and valve structure are optimized.

Precision Tension Control System Using Magnetic Particle Clutch

The control of the stability of the filament tension is one of the crucial techniques ensuring the component quality of the composite materials. The open-loop tension control system, with industrial control computer as the core, magnetic particle clutch as the actuator, equipped with compensation technique is researched and manufactured. It can assure the tension control stability of the yarn in filament winding process and increase the control precision of the whole system.

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.

Sliding Mode Control Approach for Electrically Controllable Clutch of AMT Based on the Feedback Linearization

A sliding mode control approach based on the feedback linearization is proposed for the electrically controllable clutch of AMT vehicles. The nonlinear dynamic model for the hydraulic actuator associated with clutch is established. By means of the exact feedback linearization procedure of differential geometry, an equivalent, fully controllable and linear model is derived via a homomorphic transformation for the AMT clutch system.Furthermore, a sliding mode control is introduced to improve robustness. The tracking tests are performed using the sliding mode control on a Santana LX passenger car, and the experimental results prove that this nonlinear controller is of fine robustness and high degree of tracking accuracy.

Study of engaged performance regulation in controlled transfer clutch of 4WD car based on genetic sliding mode control

This paper investigates an approach to improve the engagement quality of controlled transfer clutch mode in 4 wheel drive(WD) car from three considerations of reducing friction,smoothening responsiveness and alleviating jerk.The method utilizes an improved sliding mode control with genetic algorithm instead of simplified mode to determine appropriate values of parameters in control close- loop.The simulation results show that the method is effective for improving the engagement quality of coupling satisfying different design needs for 4WD car,as well as robustness even if input torque is changed at a certain range.

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。

混合动力船舶电机辅助主机合排控制方法及实船应用

为了解决某型7 500 t级散货船在主机合排过程中存在浓烈黑烟问题,通过实船数据分析问题原因并提出电机辅助主机合排的控制方法,调整实船主机合排控制策略与优化控制程序,经过实船试验验证表明,采用电机辅助的主机合排控制过程相较于无电机辅助的主机合排控制过程,其螺旋桨轴系扭矩突增量减小33%,主机油耗突增量减小35%,尾轴转速突增量减小41%,且螺旋桨轴系扭矩与尾轴转速上升速率更平缓,有效解决主机冒黑烟问题,达到降低主机碳排放的目的。在船舶营运过程中,混合动力系统设备运行情况良好。

考虑离合器摩擦性能衰减的湿式DCT车辆起步控制研究

建立了考虑离合器摩擦系数变化及离合器性能衰减的湿式双离合变速器(dual clutch transmission,DCT)车辆起步过程动力学模型,以车辆起步过程冲击度、滑摩功和起步滑摩时间为优化目标,采用线性二次型最优控制方法获得了车辆起步过程离合器最优传递转矩。针对离合器摩擦系数变化及离合器性能衰减对车辆起步过程离合器压力控制的影响,提出了一种离合器压力非线性鲁棒控制策略,以实现对离合器最优传递转矩的跟踪。结果表明,所提出的非线性鲁棒控制策略能够在离合器摩擦系数变化的情况下实现对离合器最优传递转矩的有效跟踪,跟踪误差不大于0.02 N·m,且能够适应摩擦性能衰减导致不同寿命阶段摩擦系数的不同变化规律,与比例-积分-微分(proportion-integral-differential,PID)控制策略相比具有更精确的控制效果和更强的鲁棒性。

两挡混动变速器低成本液压系统开发

传统变速器和混动变速器的液压系统一般采用先导比例电磁阀和滑阀组合的形式控制主压,主压经过比例减压阀调压之后成为离合器控制压力,此类液压系统较为复杂,成本较高。为降低混动变速器的成本,开发基于节流孔调节离合器控制压力的液压系统,通过AMESim仿真软件进行仿真计算,节流孔孔径设计值为0.70 mm,为保证产品的一致性,减少制造误差的影响,节流孔孔径的公差值为±0.015 mm。经过制作样件,搭载混动变速器进行试验,结果验证有效,满足设计需求。

基于FIPID的PST湿式离合器压力控制方法

拖拉机动力换挡过程中湿式离合器油压实际值与目标值存在偏差,在此采用模糊免疫PID(Fuzzy Immune PID,FIPID)控制方法,以便对离合器油压实现跟随控制。构建湿式离合器驱动执行机构的数学模型,设计湿式离合器的模糊免疫PID控制器,并基于MATLAB/Simulink和AMESim平台分别建立控制模型和液压模型,对接合过程进行仿真分析。仿真结果表明:在方波信号下,模糊免疫PID的动态响应时间仅为0.069 s,正弦信号下的稳态误差为±0.020 1 MPa,跟踪控制效果优于PID与模糊PID,实现了离合器压力的有效跟踪控制。在运输工况下,与PID和模糊PID相比,模糊免疫PID的最大冲击度分别降低43%、29%,滑摩功分别增大18%、2%。在犁耕工况下,与PID和模糊PID相比,模糊免疫PID的最大冲击度分别降低53%、38%,滑摩功分别增大4%、2%。

电控气动离合器执行机构气路集成设计与研究

提出一种中央集成式嵌入型电控气动离合器执行机构,并从气路结构的集成设计、气路流体的仿真研究与气路响应性的试验研究3个方面与当前主流的半嵌入型电控气动离合器执行机构进行对比分析。结果表明,嵌入型电控气动离合器执行机构不但在零组件数量、接口数量、重量3方面具有优势,而且响应性更优。

一种刮板输送机用液控离合紧链装置结构设计

目前的刮板输送机液压紧链装置,紧链前后均需人工手动操纵其离合手柄,进而来控制液压紧链装置的惰轮和刮板输送机减速器输入轴的紧链齿轮之间的结合与分离。为了解放人工,提升作业效率,设计了一种液控离合紧链装置结构:减速器+液压离合器+低速大扭矩液压马达组合。该结构的特点是需要紧链时,直接远程操控该紧链装置油液系统的连接工作即可。该结构的减速器以花键连接方式在刮板输送机链轮组件的内腔,随着连接和关闭液压离合器的油液提供,控制液压离合器这个中间连接件的吸合和分离,达到减速器和液压马达之间的扭矩、速度传递和断开。通过对该结构的详细方案分析和工作原理推理,结果表明:该结构是能够实现自动化紧链功能的。

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。

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.

Strategy to control crawling vehicles with automated mechanical transmission

In order to move vehicles with automated mechanical transmission （AMT） a little bit of distance, such as reversing into or moving in a garage, a control strategy for crawling vehicles was proposed. Based on the dynamic analysis of vehicle starting process and requirements of crawl driv- ing for the vehicle, a control strategy of the clutch was designed. The strategy increased the.slipping friction torque first and then decreased it, in order to realize the crawl driving. The speed increased by the engagement of the clutch, and then the clutch turned to disengage to the half disengage point, when the speed met the requirements. Based on the control strategy, a control software was de- signed. In the end, the software was tested on a vehicle with AMT. The lowest steady vehicle speed was reduced to 40% of the original value, which was set in the control strategy.

Review on development progress of automatic manual transmissions control

In recent years, the sustainable development of automatic manual transmissions (AMTs) control in vehicles is conspicuous. The control applications have grown fast and steadily due to the tremendous progress in power electronics components and the control software that enhance the requirements for delivering higher vehicles performance. AMTs control strategies achieve a reduction in the driveline dynamic oscillations behavior during gear shifting and clutch starting up processes. AMTs future expectations are an increase of torque capacity, more speed ratios and the development of advanced and efficient electronic control systems. This paper concerns with the progressing view of AMTs in the past, today and future, gives an overview of the potential dynamic problems concerned with AMTs and some control strategies used to solve those problems.

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.

Simulation study on starting of dual clutch transmission for tracked vehicles

In order to study the application of dual clutch transmission （DCT） on tracked vehicles, a simulation moclel and two control methods were performed for starting analysis. Based on a certain transmission of an existing tracked vehicle, a DCT structure was proposed. Matlab/Simulink was a dopted as a platform to develop the simulation model. The engine speed was controlled to follow the target speed as a launch strategy. Two control methods, a proportional integral derivative （ PID ） control method and a fuzzy control method, were proposed to control the engine throttle and oil pressure in order to track the target engine speed. Simulation results show that either the PID control or fuzzy control method can improve the starting performance compared with no loop control meth od. Fuzzy control method can lead a better starting quality compared with PID control method.