横摆力矩控制系统液压回路的设计

简单介绍了汽车横摆力矩控制(DYC)系统，着重介绍了一种基于汽车防抱制动装置(ABS)的DYC液压回路的设计。     

汽车EPS试验台液压控制系统设计

根据汽车电动助力转向系统（EPS）及路面阻力的特点,分析了电动助力转向试验台液压加载装置的主要功能需求,设计了此液压控制系统。介绍液压加载装置的结构和工作方式,着重研究了液压加载装置控制系统的控制过程及其功能的实现,并进行了功能测试。     

整体式动力转向系统转向沉重的排除方法

1．液压动力转向系统的结构 为了减轻驾驶员操作的疲劳强度，并减少路面对方向盘的振动响应，目前在载货汽车和轿车上已普遍应用动力转向装置。动力转向装置的动力源可来自压缩空气、电力和液压。液压动力转向装置由于工作压力较高、外廓尺寸较小、油液对路面有吸振作用等优点而被广泛采用。液压动力转向系统主要由液压油泵、转向器总成、贮油箱和油管等组成，如图1所示。     

汽车助力转向系统及其相关标准分析

对汽车用机械液压助力转向系统、电子液压助力转向系统和电动助力转向系统的原理、优点、缺点及相关标准进行了阐述和分析。     

燃料电池汽车电动液压助力转向系统设计研究

电动液压助力转向系统的设计研究在燃料电池汽车整车开发中有着非常重要的意义。文章介绍了燃料电池汽车电动液压助力转向系统设计及不同的系统控制设计方案,并进行对比分析,得出了较优的燃料电池汽车转向系统设计方案。研究结果对燃料电池汽车电动液压助力转向系统的开发设计具有重要的参考价值。     

汽车动力转向系检测仪

汽车的转向系是汽车的主要组成部分之一,转向系统的性能直接影响着汽车的操纵稳定性和安全性.随着液压技术的发展,液压转向系统已被广泛应用于汽车转向机构中,即在机械转向系的基础上加装转向液压式助力装置.汽车转向系统在使用过程中,由于机件磨损或损坏,转向性能会下降,即产生故障,而产生故障的部位主要有机械连接部分和液压部分两个方面.转向系统的机械连接部分的故障如转向系传动链过紧或卡滞、横拉杆球头部位松旷、转向节主销与衬套磨损、车轮轮毂轴承间隙过大等比较容易排除,关键是汽车的动力转向系统的液压油路中连接着转向泵、动力转向器、转向油罐和油管等,致使液压油路部分的故障不易诊断.检测液压动力转向系统最简捷而有效的方法就是设计一台动力转向系检测仪器.     

丰田锐志电动助力转向系统原理与检修

新款锐志乘用车装备的是目前较新型的电动转向装置。现代汽车的动力转向，有液压式和电动式两种类型，绝大多数汽车采用液压动力转向。由于电动助力转向系统具有一系列的优点，所以在现代汽车上使用日益增多。电动助力转向有两种基本形式，即电液转向系统和电动助力转向系统。锐志乘用车电动转向助力系统由电机提供动力。该电动转向的结构比较复杂，技术含量较高。本文对该系统的结构及基本原理及其常见故障进行分析，希望对同行能有所帮助。     

除雪车液压系统设计计算

设计了一种由装载机底盘改装而成的除雪车的液压系统,阐述了除雪车工作装置回路和转向回路的原理,并时液压系统和元件进行了计算,最后对液压泵和发动机功率进行了校核。对液压系统及工作装置的理论计算表明：改装后的除雪车各项性能满足设计要求,能正常、稳定工作。     

汽车助力转向系统转向沉重故障的诊断与检修

正汽车转向系统是影响汽车操纵稳定性的重要因素,助力转向系统因其转向轻便、操纵性好、能有效的减轻驾驶员驾驶疲劳而得到广泛应用。常见的汽车助力转向系统有液压助力和电动助力转向两种,这两种助力转向系统都是在机械转向系统的基础上加设液压或电动助力装置部分得到的,这样在助力部分失效的情况下仍然可以利用机械转向系统实现转向,只是转向时会很沉重。这就属     

别克君威轿车动力转向系统常见故障诊断与排除

别克君威轿车动力转向系统采用的是带液压助力的齿轮齿条式转向机构,由一个齿轮齿条式的机械转向器和液压助力装置组成。液压助力装置的工作压力可高达10 MPa以上,液压助力装置工作时无噪声,工作滞后时间短,而且能吸收来自不平路面的冲击。通过动力转向系统减轻了转向时驾驶人的劳动强度,     

车辆动力学控制系统横摆力矩控制方法

车辆动力学控制系统(VDC)通过对车辆施加主动横摆力矩来改善车辆高速时的操纵稳定性,可有效避免侧滑等交通事故,研究其横摆力矩控制方法是当前车辆动力学领域的热点。在研究先进控制理论的基础上,分别设计了用于VDC系统的鲁棒、模糊和智能积分模糊PID控制器,并将它们和车辆系统模型联接进行了系统仿真,对比分析了3种控制器的控制特点与控制效果。仿真结果表明,鲁棒、模糊和智能积分模糊PID控制方法都能实现有效的横摆力矩控制,且有各自的特点。智能积分模糊PID控制效果更为理想,该方法应用于VDC控制具有很好的前景。智能积分降低了积分功能的副作用,进一步提升了模糊PID的控制效果。仿真工作为进一步将智能积分模糊PID应用于VDC系统样机开发提供了参考。     

Integrated control of brake pressure and rear-wheel steering to improve lateral stability with fuzzy logic

This study introduces an integrated dynamic control with steering (IDCS) system to improve vehicle handling and stability under severe driving conditions. It integrates an active rear-wheel steering control system and a direct yawmoment control system with fuzzy logic. Direct yaw-moment control is achieved by modifying the optimal slip of the front outer wheel. An 8-degree-of-freedom vehicle model was used to evaluate the proposed IDCS for various road conditions and driving inputs. The results show that the yaw rate tracked the reference yaw rate and that the body slip angle was reduced when the IDCS was employed, thereby increasing the controllability and stability of the vehicle on slippery roads. The IDCS system reduced the deviation from the center line for a vehicle running on a split m road.     

多电机电动车动力学系统隐模型跟踪控制

提出一种应用隐模型跟踪最优二次型调节器的车辆动力学控制方法,为多电机独立驱动电动车设计了直接横摆力偶矩控制器,通过仿真计算证明了该控制方法的有效性。     

A curving ACC system with coordination control of longitudinal car-following and lateral stability

The paper presents a curving adaptive cruise control (ACC) system that is coordinated with a direct yaw-moment control (DYC) system and gives consideration to both longitudinal car-following capability and lateral stability on curved roads. A model including vehicle longitudinal and lateral dynamics is built first, which is as discrete as the predictive model of the system controller. Then, a cost function is determined to reflect the contradictions between vehicle longitudinal and lateral dynamics. Meanwhile, some I/O constraints are formulated with a driver permissible longitudinal car-following range and the road adhesion condition. After that, desired longitudinal acceleration and desired yaw moment are obtained by a linear matrix inequality based robust constrained state feedback method. Finally, driver-in-the-loop tests on a driving simulator are conducted and the results show that the developed control system provides significant benefits in weakening the impact of DYC on ACC longitudinal car-following capability while also improving lateral stability.     

Hierarchical Direct Yaw-Moment Control System Design for In-Wheel Motor Driven Electric Vehicle

In this study, a hierarchical structured direct yaw-moment control (DYC) system, which consists of a main-loop controller and a servo-loop controller, is designed to enhance the handling and stability of an in-wheel motor driven driven electric vehicle (IEV). In the main loop, a Fractional Order PID (FO-PID) controller is proposed to generate desired external yaw moment. A modified Differential Evolution (M-DE) algorithm is adopted to optimize the controller parameters. In the servo-loop controller, the desired external yaw moment is optimally distributed to individual wheel torques by using sequential quadratic programming (SQP) approach, with the tire force boundaries estimated by Unscented Kalman Filter (UKF) based on a fitted empirical tire model. The IEV prototype is virtually modelled by using Adams/Car collaborating with SolidWorks, validated by track tests, and serves as the control plant for simulation. The feasibility and effectiveness of the designed control system are examined by simulations in typical handling maneuver scenarios.     

Slip-Angle Estimation for Vehicle Stability Control

Recently, some direct yaw-moment control systems have been in development. Obviously, such systems need accurate slip-angle information. This paper describes a strategy of vehicle slip angle estimation. The difficulty in slip angle estimation is due to nonlinear characteristics of tyres and influence of relative slant of the road surface. To solve this difficulty, a combined method of model observer and direct integration method is proposed. In this method, two kinds of values of the side forces of the wheels are provided, i.e., direct detected values by the G-sensor and values from a tyre model. Then those values are combined appropriately which results in the combination of model observer and direct integration. A feedback algorithm, redesigned to suppress the influence of tyre model error, is applied in the observer. Considering interference of road surface and its avoidance, road slant angle is estimated and consequently vehicle model is corrected. The estimated value of the road friction coefficient is given by the acceleration, and an adequate bias, depending on yaw-deviation, is added. The calculation method of reference yaw-velocity is improved, in order to avoid interference of road slant and variation of dynamic characteristic of vehicle.     

Slip-Angle Estimation for Vehicle Stability Control

Recently, some direct yaw-moment control systems have been in development. Obviously, such systems need accurate slip-angle information. This paper describes a strategy of vehicle slip angle estimation. The difficulty in slip angle estimation is due to nonlinear characteristics of tyres and influence of relative slant of the road surface. To solve this difficulty, a combined method of model observer and direct integration method is proposed. In this method, two kinds of values of the side forces of the wheels are provided, i.e., direct detected values by the G-sensor and values from a tyre model. Then those values are combined appropriately which results in the combination of model observer and direct integration. A feedback algorithm, redesigned to suppress the influence of tyre model error, is applied in the observer. Considering interference of road surface and its avoidance, road slant angle is estimated and consequently vehicle model is corrected. The estimated value of the road friction coefficient is given by the acceleration, and an adequate bias, depending on yaw-deviation, is added. The calculation method of reference yaw-velocity is improved, in order to avoid interference of road slant and variation of dynamic characteristic of vehicle.     

Experimental investigations on continuous regenerative anti-lock braking system of full electric vehicle

Functions of anti-lock braking for full electric vehicles (EV) with individually controlled wheel drive can be realized through conventional brake system actuating friction brakes and regenerative brake system actuating electric motors. To analyze advantages and limitations of both variants of anti-lock braking systems (ABS), the presented study introduces results of experimental investigations obtained from proving ground tests of all-wheel drive EV. The brake performance is assessed for three different configurations: hydraulic ABS; regenerative ABS only on the front axle; blended hydraulic and regenerative ABS on the front axle and hydraulic ABS on the rear axle. The hydraulic ABS is based on a rule-based controller, and the continuous regenerative ABS uses the gain-scheduled proportional-integral direct slip control with feedforward and feedback control parts. The results of tests on low-friction road surface demonstrated that all the ABS configurations guarantee considerable reduction of the brake distance compared to the vehicle without ABS. In addition, braking manoeuvres with the regenerative ABS are characterized by accurate tracking of the reference wheel slip that results in less oscillatory time profile of the vehicle deceleration and, as consequence, in better driving comfort. The results of the presented experimental investigations can be used in the process of selection of ABS architecture for upcoming generations of full electric vehicles with individual wheel drive.     

选择性输出双离合自动变速器液压控制系统设计

液压控制系统是变速器的重要组成部分,油路和阀的设计选择对变速器的动力传递和换挡实现有很大影响。分析了自动变速器液压系统的控制原理,并结合一种新型结构变速器,设计其液压控制系统来满足其换挡和动力传递需要。     

采用微处理机对变量液压泵的扩充控制

讨论了微处理机在变量液压泵反馈回路中的应用。对四种常见的控制方式作了研究 ,这些控制方式通常是用各种不同的控制器实现的 ,微处理机和控制用步进电动机结合 ,能够满足液压泵在所有四种控制方式中的工作 ,从而大大增加了液压系统的通用性。