湿式离合器先导式电液调压阀时频域建模与分析

先导式电液调压阀是大功率湿式离合器换挡系统的核心部件,由于其多个环节存在参数时变和强非线性特征使其频率响应特性发生变化,进而影响换挡过程的油压调节的快速性与稳定性。在剖析先导式电液调压阀工作原理的基础上,考虑阻尼系数、流量系数和增益系数随油温的可变性,建立了先导式电液调压阀在工作过程中的数值模型,并推导了其频域模型。研究了先导式电液调压阀在不同参数下的时域和频域响应特性,得到了参数变化的影响规律。结果表明：增加系统响应的带宽会提高油压响应速度,但会降低阻尼比,使得油压响应的调节时间增加。系统的结构参数、输入信号以及工作油温均会影响其响应特性。基于该方法能够快速的判断先导式电液调压阀在全工作范围内的响应速度和稳定性问题,从而有助于改善先导式电液调压阀的油压动态跟踪性能。     

机械式自动变速器重型军用轮式车辆坡道起步控制策略研究

针对机械式自动变速器(AMT)重型军用轮式车辆坡道起步的问题,提出了车辆坡道起步控制策略。通过对试验车辆坡道起步过程进行动力学分析,结合发动机转速特性曲线,提出了基于油门开度、发动机转速和发动机转速下降率来估算离合器传递转矩的思想,并确定了驻车制动释放的条件。在试验车辆AMT系统硬件条件的基础上,设计了离合器的控制策略并编写了控制软件。分别在不同坡道上进行了多次试验,均取得了理想的效果。试验结果表明:研究过程中所提出的理论和方法正确,可实施性强,能够很好地满足AMT重型军用轮式车辆在不同坡道上的起步要求。     

Optimal gear shift control strategy for positive independent mechanical split path transmission with automatic shift system

An improvement strategy which controls the shift effort and the power summing planetary gear set of steering clutches and brakes have been proposed based on the dynamic model of synchroniser in order to decrease the wear of synchroniser inserts,make gear shift easy and reduce the shock noise for a positive independent mechanical split path transmission which attached an automatic shift system when shifting.A kinetics model for the process of synchroniser engagement is built and analyzed in the paper.Thus for optimizing the gear shift process which is divided into three phases a model reference fuzzy self-adaption system is adopted.Through a 6000 km road experiment,the control strategy has proved feasible and dependable.     

Study on Control of Pneumatic Selecting and Shifting Actuators Using Rapid Control Prototyping

A gearbox in-the-loop control platform using dSPACE real-time system is designed for the study on the control technology of pneumatic selecting and shifting actuators based on rapid control prototyping. The operational principle of such actuators was analyzed using dSPACE hardware and software, resulting in a better knowledge of the logical relationship among solenoid valves, gear positions of cylinders and system input／output. Based on these, a control model was developed under the Matlab／Simulink environment and rapidly improved to meet requirements through experiments. Relevant tests have shown that analysis efficiency on selecting and shifting actuators could be raised and development of control strategy facilitated.     

Development of AMT Fault Diagnosis Technique Based on KWP2000

In order to make automatic mechanical transmission (AMT) capable of performing fault self-diagnoses and adaptive to standard communication interface,through technical analysis and intensive study concerning on-board diagnostic protocols now widely applied in Europe and America,KWP2000 on CAN is accepted as a technological path.An AMT fault communication system using hardware-in-the-loop simulation by dSPACE is developed,and communications compatible with ISO 15031-6 is realized on this module.Moreover,a han...     

气压驱动式自动离合器控制技术研究

为了以较低成本实现AMT系统中离合器执行机构的气压驱动,在对离合器控制过程深入分析的基础上结合气动控制特点,提出了通过高速开关电磁阀以PWM方式驱动纯气动离合器执行机构的方法,及离合器参考模型自适应控制方法.通过多位驾驶员在不同道路条件和环境条件下的实车道路考核,验证了这种控制方法的可行性,研究结果同时表明:采用该方法的离合器执行机构价格低廉,为进一步实现产业化奠定了基础.     

正独立式机械双流传动装置自动换挡技术

某履带式自行火炮装用手动操纵的正独立式机械双流传动装置，在实际使用过程中由于经常出现起步档选择不合理，导致主离合器过度磨损，影响了车辆的使用寿命。为此对原车的换档操纵系统进行了改进设计，即在原车上增加电液自动换档操纵系统，取代原车的机械换档操纵系统。通过实车试验证明，所加装的电液自动换档操纵系统解决了主离合器过度磨损的问题，同时实现了车辆的自动换档操纵。     

Analysis on the gear-shifting schedule of hydraulic automatic transmission

With an advanced foreign hydraulic automatic transmission as the objective, an analytical method for the gear-shifting schedule is proposed. First the demanded maximum gradient of test is estimated. Then a test scheme and analytical procedure is formulated by initial test and hypothetical shift parameters. Finally through gear-shifting tests under different road conditions, load, accelerator pedal position limitation, throttle opening and output shaft speed are found to be the gear-shifting parameters. Under a common road condition, the gear-shifting schedule is a double-parameter schedule. Based on the driver''s demands on braking and dynamic performance, different shift schedules are made under downhill, uphill and quick releasing acceleration pedal conditions. The operation criteria of down-shift schedule on abrupt grade are proposed.     

并联混合动力城市客车AMT换挡控制策略

为了实现混合动力城市客车快速换挡,减少动力中断时间,基于质量-弹簧-阻尼模型对并联混合动力传动系统进行动力学建模．提出利用线性二次高斯和回路传输恢复(LQG/LTR)方法设计摘挡控制器,对摘挡阶段转速振荡进行主动抑制;设计基于模型预测控制(MPC)理论的电机转矩调节器以最小化主动同步时发动机转矩脉动,实现快速同步,并适应混合动力多运行模式带来的离合器状态的不确定性．对上述混合动力AMT换挡过程控制策略分别进行仿真和实车平台验证,试验结果表明:该策略能够将换挡时间控制在1 s内,且冲击度处于合理范围内．应用上述换挡控制策略有助于提高城市客车的舒适性,推进混合动力城市客车AMT系统的产业化．     

基于CCP的AMT电控单元标定系统开发

为方便、快捷、稳定地对AMT电控系统进行标定,采用基于CCP协议的通讯标准,以某AMT系统为平台,开发了AMT电控系统标定仪。试验证明,所设计的标定仪能较好的实现预期功能且性能稳定。