提高AMT车辆换挡品质控制策略与试验研究

提出换挡过程中通过控制发动机上的断油电磁阀来改善AMT换挡品质的新方法,制定断油电磁阀与离合器接合控制策略,并在装有AMT的某重型载货汽车上进行试验。试验结果表明,换挡过程中通过控制断油电磁阀和设置换挡重叠并与离合器的接合过程相协调,可显著提高AMT的换挡品质。     

重型混联式混合动力车辆换挡品质控制参数设计与优化

在重型混联式混合动力车辆换挡过程对发动机和电机进行主动调速的品质控制基础上,针对影响控制品质的换挡操作元件(离合器或制动器)充放油缓冲特性与充放油速率等参数进行了设计,以换挡品质评价指标为优化目标,对缓冲充油速率与接合速差等关键换挡品质控制参数进行了多目标优化。结果表明:研究得到的控制参数使换挡品质大幅提高,符合换挡品质指标要求;研究得到的参数设计与优化方法正确、有效。     

摩托车湿式多片式离合器结合过程分析及起步过程模拟

通过分析摩托车湿式多片式离合器的结合过程,建立了摩托车离合器结合过程的数学模型,并在此基础上研究开发了摩托车湿式多片式离合器起步模拟试验台.试验台能够进行离合器分离过程试验、起步模拟试验;利用磁粉制动器和惯性轮分别模拟摩托车在4°35 '坡道上、处于满载常用起步挡时,折算到离合器的坡道阻力矩和当量惯量,进行离合器起步过程模拟.试验表明,测试系统可靠性高,测量精度高.     

自动变速器静态换挡充油特性分析及优化控制

为了解决自动变速器静态换挡中充油阶段结束时刻离合器油压波动问题,分析了静态换挡的关键充油特性并提出了充油阶段的优化控制策略。构建了包括手动阀、液控换向阀和离合器的机电液多物理耦合的仿真模型并进行仿真分析。结果表明,优化控制策略可以明显缩小充油阶段结束时刻离合器的油压波动,证明了提出的控制策略的可行性、正确性与有效性。     

基于扭矩控制的AMT换挡控制策略研究

提出在车辆起步和换挡过程中通过CAN动力网络控制发动机的输出扭矩来改善AMT换挡品质的新方法,制定扭矩控制与离合器接合控制策略,并在装有AMT的某重型商用车上进行试验。试验结果表明,换挡过程中通过控制发动机的输出扭矩并与离合器的接合过程相协调,可显著提高AMT的换挡品质。     

电控自动变速器升挡转矩相控制策略

为动态分析自动变速器换挡过程中的转矩相,建立了动力换挡系统模型.针对传统控制策略所产生的换挡冲击问题,基于改善换挡平顺性的要求提出理想转矩相的控制目标,以变化的转矩变化率代替传统控制策略固定的转矩变化率.为减小油温、载荷等工况的变化对转矩相控制过程的扰动,设计了模型参考自适应控制器,并以待分离离合器速差的变化率作为反馈变量对开环控制参数进行自适应修正.实车试验验证了所提出的控制策略可有效减小自动变速器的换挡冲击.     

基于发动机联合控制的AMT换挡控制策略

分析了AMT换挡类型,提出了基于CAN总线的发动机联合控制策略,即TCU通过CAN及ECU扭矩控制功能对发动机扭矩进行精确控制,同时基于发动机瞬态扭矩对离合器实现精确分离和接合控制.针对不同换挡工况给出了离合器分离/接合与发动机降扭/扭矩恢复协调控制策略,同时提出了选换挡过程动态调整转速控制策略.试验结果表明,所提策略可以增强AMT换挡过程的平顺性和动力性,减小离合器滑摩,且具有很好的鲁棒性,有助于提高AMT换挡品质.     

TC+AMT换挡离合器控制参数设计与优化

简述了某车辆采用的TC+AMT自动变速系统结构,并针对影响该车换挡品质的换挡离合器充放油特性与充放油规律进行了离合器控制参数的设计.由换挡品质评价指标构造优化目标函数,对缓冲充油速率与结合速差等关键控制参数进行多目标优化.给出了离合器最优控制规律.对装有TC+AMT自动变速系统的样车进行了100％油门开度下1挡升2挡试...     

VFS电磁阀颤震压力异常的研究

提高换挡质量,需兼顾速度与换挡平顺性。对于自动变速器,采用非工作离合器预充油压策略即保持非工作离合器的颤震油压,是提升换挡速度比较重要的控制策略之一。文章论述了自动变速器液压控制策略中非工作离合器颤震压力标定过程以及在标定过程中异常数据的发现,并对颤震压力异常从实验排查、过程控制等方面进行深入研究。     

自动变速器故障诊断思路剖析(四)

蓄压器也称蓄能器或减震器,用于提高换挡品质,是最常见的控制换挡进程的部件。蓄压器的工作原理如图8所示,它由活塞、弹簧及壳体组成。蓄压器与离合器或制动器油路并联安装,在工作油液进入离合器或制动器的活塞腔的同时,也进入蓄压器,蓄压器内的活塞受力下移,这减缓了工作压力的迅速增长,防止因换挡过速而引起的冲击。如果蓄压器的背压侧只有一个弹簧,它只有一个固定的缓冲量,这并不能满足在不同工况下换挡的需要。为了使蓄压器的缓冲程度可控且与节气门开度有关,在蓄压器活塞的弹簧端(背压侧)还同时作用着节气门油压或主油压或专门的蓄压器油压。节气门油压的存在使离合器或制动器油压的建立过程加快,在节气门开度加大时,节气门油压升高,加快换挡进程,防止在传递大扭矩时换挡执行元件打滑,从而满足汽车在各种行驶条件下对换挡过程的不同要求。     

自动变速器车辆换挡品质研究

为了改善液力自动变速器的换挡品质,通过对自动变速器换挡过程的分析,采用电磁阀控制换挡离合器接合分离的方法,基于Simulink建立了换挡电磁阀控制系统模型,包括电磁阀工作逻辑控制和开闭合曲线控制模型。利用该模型,对换挡过程中电磁阀控制规律的变化对换挡冲击度的影响进行了分析。为了进一步验证开发方向和控制策略的正确性,设计了基于dSPACE的自动变速器快速控制原型试验并进行了试验验证。结果表明：换挡电磁阀控制系统能够减小换挡冲击度,改善换挡品质。     

多离合器式自动变速器

由于目前的各种变速器都有其自身缺陷,为了克服这些缺陷,文章提出了一种多离合器式自动变速器,并介绍了其工作过程。该变速器包括离合器、2挡或2挡以上的机械变速器、控制系统TCU。该变速器结构简单、换挡控制策略简单、传递效率高。由于在换挡过程中,一个挡位的2个离合器分离的同时,另一个挡位的2个离合器接合,因此该换挡过程不存在动力中断,能实现动力换挡,满足了车辆对变速器的各种要求。     

Simulation model of an electrohydraulic-actuated double-clutch transmission vehicle: modelling and system design

Automated and manual transmissions are the main link between engine and powertrain. The technical term when the transmission provides the desired torque during all possible driving conditions is denoted as powertrain matching. Recent developments in the last years show that double-clutch-transmissions (DCTs) are a reasonable compromise in terms of production costs, shifting quality, drivability and fuel efficiency. They have several advantages compared to other automatic transmissions (AT). Most DCTs nowadays consist of a hydraulic actuation control unit, which controls the clutches of the gearbox in order to induce a desired drivetrain torque into the driveline. The main functions of hydraulic systems are manifold: they initiate gear shifts, they provide sufficient oil for lubrication and they control the shift quality by suitably providing a desired oil flow or pressure for the clutch actuation. In this paper, a mathematical model of a passenger car equipped with a DCT is presented. The objective of this contribution is to get an increased understanding for the dynamics of the hydraulic circuit and its coupling to the vehicle drivetrain. The simulation model consists of a hydraulic and a mechanical domain: the hydraulic actuation circuit is described by nonlinear differential equations and includes the dynamics of the line pressure and the proportional valve, as well as the influence of the pressure reducing valve, pipe resistances and accumulator dynamics. The drivetrain with its gear ratios, moments of inertia, torsional stiffness of the rotating shafts and a simple longitudinal vehicle model represent the mechanical domain. The link between hydraulic and mechanical domain is given by the clutch, which combines hydraulic equations and Newton's laws. The presented mathematical model may not only be used as a simulation model for developing the transmission control software, it may also serve as a virtual layout for the design process phase. At the end of this contribution a parametric study shows the influence of the mechanical components, the accumulator and the temperature of the oil.     

Shifting control of an automated mechanical transmission without using the clutch

The automated mechanical transmission (AMT) is gaining popularity in the automotive industry, due to its combination of the advantages of mechanical transmissions (MT) and automatic transmissions (AT) in terms of fuel consumption, low cost, improved driving comfort and shifting quality. However, the inherent structural characteristics of the AMT lead to disadvantages, including excessive wear of the clutch plates and jerk and traction interruption during the shift process, that severely affect its popularity in the automatic transmission industry. The emerging technology of shifting control without the use of the clutch is a promising way to improve the shifting transients of AMTs. This paper proposes a control algorithm that combines speed and torque control of the AMT vehicle powertrain to achieve shifting control without using the clutch. The key technologies of accurate engine torque and speed control and rapid position control of the shift actuators are described in detail. To realize accurate engine speed control, a combined control algorithm based on feed-forward, bang-bang and PID control is adopted. Additionally, an optimized closed-loop position control algorithm based on LQR is proposed for the shift actuators. The coordinated control algorithm based on engine and shift actuator control is described in detail and validated on a test vehicle equipped with an AMT. The results show that the coordinated control algorithm can achieve shifting control without the use of the clutch to improve driving comfort significantly, reduce shift transients and extend the service life of the clutch.     

六速双离合器自动变速器开发

简述了某六速双离合器自动变速器的机械传动系统结构,给出了该变速器最佳动力性换挡策略,并进行了NVH仿真分析.对所开发的液压阀体总成进行的试验表明,该阀体总成的挡位平均响应时间为30.6 ms,比目前国外同类样品响应时间快.介绍了所开发的湿式双离合器结构并进行了双离合器总成试验.结果表明,双离合器1可进行精确地换挡控制;双离合器2虽然能进行换挡,但不易进行精确控制.     

液力变矩器滑摩离合器控制压力计算方法

自动变速器中的滑摩离合器滑摩时发动机的动力同时通过液力传动和机械滑摩传动两条路线传递,它能够在大范围内提高传动效率。文中推导了汽车自动变速系统在滑摩过程中的功率平衡方程,并利用该方程计算了滑摩过程的控制油压,选择合理的滑摩控制区域能够显著提高自动变速传动系统的传动效率和缓冲、抗振性能。该控制区域应该从发动机的扭振状况、变矩器离合器的滑摩率和功率分配比、变矩器的输出特性以及自动变速系统的换挡规律多个方面进行考虑。     

Adaptive control of the shifting process in automatic transmissions

This paper focuses on the way of keeping shift quality of automatic transmissions consistent in mass production and with mileage accumulation. We investigate the main factors influencing the consistency of shift quality. Test results show that the torque to pressure (T2P) and pressure to current (P2I) characteristics of shifting elements are easily affected. A simulation model of an 8-speed automatic transmission is established to simulate the dynamic process of clutch-to-clutch shift. Simulation results demonstrate that the change of T2P and P2I characteristics has a significant influence on shift quality. In order to compensate for the influences, we develop two adaptive control strategies, i.e., the adaptive control strategies for torque phase and inertia phase. They make use of the measured speed information and time information to evaluate shift quality. Then the control parameters are tuned to adapt to the change of T2P and P2I characteristics. Vehicle tests verify that the developed adaptive control strategies are effective to keep shift quality consistent in mass production and with mileage accumulation.     

自动变速器湿式离合器摩擦片接合特性的测试方法研究

自动变速器湿式离合器摩擦片的测试装置可以通过变更滑动速度、转动惯量、法向作用力和润滑油量,测量得包括法向力、制动力矩、滑动速度和随时间变化的温度等数据。这些输入参数与所得到的输出数据与工程机械自动变速器中的参数与数据极为相似。     

离合器到离合器式自动变速器控制系统的试验研究

在台架上对某一离合器到离合器式自动变速器的控制系统进行了试验研究.结果表明,影响换挡品质的控制参数有初始结合控制参数、初始分离控制参数、填充时间控制参数、离合器结合控制参数变化率和分离控制参数变化率.通过试验测得了该变速器在不同换挡条件下,上述参数的选用值,为此类变速器控制系统的设计提供参考.     

Method for precise controlling of the at shift control system

The shift comfort and efficiency of Automatic Transmission in vehicle are highly influenced by the pressure of the clutch shift control system, especially by the electro-hydraulic clutch subsystem. In this paper, the new design principles of electro-hydraulic clutch systems developed and modeled in detail, the clutch-to-clutch control system is analyzed in three time intervals: oil filled phase, changing phase of clutch torque and synchronous phase of clutch speed. The demand pressures for the engaged clutches calculated in each phase and is precisely built up by using fuzzy slide mode control, the time of hydraulic pressure building-up is very sensitive to the dither current in simulation. All control parameters are optimized by Cosimulation between software Simulink and SimulationX. Finally, the optimal algorithm of the clutch shift control is written into the transmission control unit of a testing vehicle. The testing results show that the suggested control strategy is effective.