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《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2012,50(5-6):333-343
ABSTRACT Large control forces in vehicle suspension systems or other vibration control systems may often be generated effectively by modulating the dissipation characteristics of an element using only modest control power. Most of the systems proposed in the past have involved hydraulic dampers, but a variety of other resistive elements can also be used. What is required is an efficient transducer from mechanical power to another form of power and a means to modulate a generalized resistor in the energy domain in question. Using bond graphs, it is shown that designs in the hydraulic domain can be transferred to other domains with possible benefits in certain cases. 相似文献
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J. Schoeftner W. Ebner 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2017,55(12):1865-1883
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. 相似文献
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为解决三臂液压凿岩台车油箱改造问题,使液压油箱在改造后能够满足设备使用要求,并保证液压油箱容量及系统散热性能,需计算油箱容量是否满足使用需求,验证液压系统热平衡是否合理。对于液压油箱容量方面,分别从液压油泵排量,油缸及油管的储油量,使用过程中油箱液面的变化量3个方面计算分析了液压油箱的容量问题,验证了改造后液压油箱容量满足使用要求;对于系统热平衡方面,分别计算了液压系统的动力机构发热功率、液压油箱散热功率及水冷散热功率,结合理论计算得到了解决散热问题的方法。液压凿岩台车改造后经过工厂及工业性试验,并通过实践检验了其理论计算的合理性,以期为其他设备的升级改造提供一定的借鉴。 相似文献
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H. S. Wi Y. K. Lee J. I. Park J. H. Lee K. S. Park 《International Journal of Automotive Technology》2009,10(6):771-776
This paper focuses on fuel economy improvement according to the type of power steering system. Usually, a conventional power
steering system is directly driven by the crankshaft of the engine with a belt, known as HPS (hydraulic power steering). However,
there is some inefficiency with this system at high engine speeds. To improve this inefficiency, automobile makers have developed
two power steering systems: EHPS (electro-hydraulic power steering) and MDPS (motor-driven power steering) or EPS (electric
powered steering). However, there has been insufficient study of effects of the type of power steering system on fuel economy.
In this paper, the effect of the type of power steering system on fuel economy is studied experimentally, and calculations
of the effect on vehicle fuel economy are presenting using computer simulation with AVL cruise software. The results demonstrate
that a 1% vehicle fuel economy improvement can be achieved in a vehicle with an electro-hydraulic power steering system compared
to a vehicle with a hydraulic power steering system. In addition, a 1.7% vehicle fuel economy improvement can be achieved
using a full electric power steering system in a FTP-75 driving cycle. These results could be used to choose a power steering
system. 相似文献
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提高大中液压传动的效率日渐成为系统设计的主要目标。较理想的系统应有能力在任何情况下使油泵流量恰好满足负载变化要求,而油压仅比负载压力略高一较小值。这里所介绍的是一种能感受负载的液压系统的工作原理,这能时刻根据负载情况调整泵压和流量,达到上述要求,因此具有优良的节能效果和操作性能。 相似文献
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车辆动力转向系统非线性仿真研究 总被引:1,自引:0,他引:1
车辆液压动力转向系统通过伺服阀控制压力油的方向和流量,把转向盘输入的转角信号转变为车轮的偏转角度输出。在车轮偏转过程中,影响车轮偏转的力主要是地面摩擦力和轮胎的弹性变形力,因而动力转向系统所受干扰力的基本特性是非线性的,文中结合液压系统理论和Simulink控制系统仿真软件,计算并仿真了在非线性干扰力作用下的液压式动力转向系统的动态特性。 相似文献
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N. Rosam J. Darling 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》1997,27(1):1-18
The design of passive suspension systems using conventional springs and dampers is limited by the need to compromise between vehicle ride and handling functions. The Interconnected Hydragas Suspension fitted to the current Rover 100 series partially allays this compromise by reducing the vehicle pitch stiffness witfiout affecting the bounce and roll stiffnesses. However, the vehicle body is still subject to roll during cornering manoeuvres. This paper outlines the development and simulation of a sealed low bandwidth active roll control suspension based on the existing Interconnected Hydragas System. Following a brief explanation of the Hydragas suspension operating principle die paper outlines the design of a fluid displacer or 'shuttle'. This shuttle enables control over body roll during manoeuvres by displacing fluid from one side of the car to the other. Care is taken to ensure low power consumption whilst the sealed nature of the fluid based suspension units guarantee reliable operation without leakage. Using computer simulation, the system performance is predicted and compared with experimental measurements. It is shown that roll during manoeuvres can be reduced or eliminated using a minimum of hydraulic components with only moderate power consumption and cost. 相似文献
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Suboptimal Control Design of Active and Passive Suspensions Based on a Full Car Model 总被引:4,自引:0,他引:4
Elsayed M. Elbeheiry Professor Dean C. Karnopp Professor Mohamed E. Elaraby Professor Chairman Ahmed M. Abdelraaouf Professor Vice Dean 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》1996,26(3):197-222
An optimal control design method is introduced and then applied to the optimum design of active and passive suspension systems. A basic three-dimensional 7-DOF car riding model subjected to four correlated random road inputs is considered. The design method is basically developed to allow arbitrary choice of sensors for various car state variables to be used for feedback control of each suspension unit. Previous studies show that full-state control laws and even some limited-state control laws often include feedback gains which are almost zero. Some other gains, although not zero, don't play an important role in improving the system performance measures. With the method proposed in this work, every suspension unit can have its own feedback measurements and the criterion function can be related to all state and control variables. Thus a large number of active and semi-active suspension systems with full- or limited-state control laws based on different measurement combination can be suggested, studied, and compared with each other. Instead of comparing these optimized active and semi-active suspension systems with a basic, passive suspension, the passive system itself is optimized with the same criterion. Simulations in the time domain and frequency analyses are performed, and comparisons are made among the systems in terms of r.m.s. car response measures and ISO riding comfort criterion. 相似文献
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龙建强 《筑路机械与施工机械化》2010,27(5):73-75
本文对铣刨机的液压行走系统和铣刨宽度、传动方式与铣削作业系统的进行了分析。在结合发动机特性曲线基础上,探讨了铣刨机发动机功率分配的原则。铣刨机功率分配的原则应为保证各系统功率之和与发动机目标值功率相一致,使机器有最好的动力性、经济性和作业生产率,可以为铣刨机设计提供参考。 相似文献
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随着我国经济的不断发展和汽车工业技术水平的提高,人们对生活环境提出了更高层次要求,其中混合动力轿车就是一个很好地研究方向.本文介绍几种液压传动系统、燃油发动机控制系统以及电动助力转向系统等.通过对比分析国内外混合动力系统在节能方面应用现状及存在问题;最后针对该课题进行展望并总结出一些自己对于今后工作所做出的意见与建议:... 相似文献
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Most hybrid vehicles employ the continuously variable transmission (CVT or eCVT) currently as their choice of the transmissions. Recently, an automated geared transmission (AGT) or dual clutch transmission (DCT) is being tried for some hybrid vehicles for the better fuel economy than the CVT hybrid. However, this AGT or DCT is using automated clutches which require the hydraulic power in addition to the slippage in the clutch plate invoking some energy loss as well as wear. Also, they require a motor with significant power to match to the engine power. The clutchless geared smart transmission (CGST) has no clutch and the clutch function is performed by a planetary gear system controlled by a motor-generator. The hybrid vehicles proposed here using CGST may have some merits in durability, fuel efficiency, and cost since they do not have clutches. The motor used for the clutch function can be also working for power merge with the engine in propelling the vehicle. The proposed hybrid system can be either mild hybrid or full hybrid by adopting a different capacity of battery with much smaller motor-generator due to the planetary gear system compared to the other type hybrid vehicles. In this study, the prospects of newly proposed CGST hybrid system are examined in practical aspects compared with AGT hybrid or DCT hybrid systems. 相似文献
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全液压推土机控制系统关键技术研究 总被引:2,自引:1,他引:2
介绍了全液压推土机行走控制的关键技术,重点给出了行走方向与速度控制及功率自适应控制等主要环节的控制策略和控制方法。给出的算法经实际应用检验证明可行,控制性能良好,可为同类工程机械控制提供参考。 相似文献
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电子控制液压动力转向技术是通过对传统的液压动力转向器的控制阀进行改造,增加一套通过电子控制的电动旁通阀,根据车速和方向盘的转角,控制进入转向器工作缸的助力油,从而改善车辆在高速时转向器的助力特性。本文主要介绍了电子控制液压助力转向器的组成﹑原理及特点,及其在混合动力客车上应用。 相似文献
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分布式驱动电动汽车各驱动轮转速和转矩可以单独精确控制,便于实现整车动力学控制和制动能量回馈,从而提升车辆的主动安全性和行驶经济性。但车辆在回馈制动过程中,一旦1台电机突发故障,其他电机产生的制动力矩将对整车形成附加横摆力矩,从而造成车辆失稳,此时虽可通过截断异侧对应电机制动力矩输出来保证行驶方向,但会使车辆制动力大幅衰减或丧失,同样不利于行车安全。为了解决此问题,提出并验证一种基于电动助力液压制动系统的制动压力补偿控制方法,力图有效保证整车制动安全性。以轮毂电机驱动汽车为例,首先建立了整车动力学模型以及轮毂电机模型,通过仿真验证了回馈制动失效的整车失稳特性以及电机转矩截断控制的不足;然后,建立了电动助力液压制动系统模型,并通过原理样机的台架试验验证了模型的准确性;接着,基于滑模控制算法设计了制动压力补偿控制器,并在单侧电机再生制动失效后的转矩截断控制基础上完成了液压制动补偿控制效果仿真验证;最后,通过实车试验证明了所提控制方法的有效性和实用性。研究结果表明:在分布式驱动电动汽车单侧电机再生制动失效工况下,通过异侧电机转矩截断控制和制动系统的液压主动补偿,能够使车辆快速恢复稳定行驶并满足制动强度需求。 相似文献