自动变速器滑差控制技术研究

滑差控制技术在对传统闭锁式液力变矩器结构改变不大的情况下,通过调节闭锁离合器的结合油压,控制闭锁离合器处于微小滑差量的状态。滑差控制技术可以实现提高液力变矩器传动效率目的。文章以某国产6AT自动变速器为实例,介绍了对滑差控制技术的研究,总结出了滑差控制技术对降低整车油耗和提升驾驶舒适性的作用。滑差控制技术对AT产品的控制技术升级及市场拓展起到了积极作用。文章主要阐述了open到poweronslip的控制理论。     

金属带式无级变速器电液控制系统

金属带式无级变速器机液控制系统通用性差,难以实现夹紧力和速比的任意控制.提出了一种使用液压系统内反馈机制的单一液压源开环电液控制系统,并给出了具体的解决方案.详细阐释了电液作动原理并建立了系统的模型.通过对电液控制系统进行硬件在环仿真,同时与实车实验所测得的数据进行分析表明,该电液控制系统结构简单,响应快速准确,系统稳定可靠.     

轮毂电机驱动汽车区域极点配置横向稳定性控制

分布式驱动结构给车辆动力学控制带来机遇和挑战,如何可靠地实现其横向稳定性控制是关键技术。考虑车辆参数的不确定性,提出了基于区域极点配置的轮毂电机驱动汽车横向稳定性控制策略,分析了保性能权重矩阵参数对控制性能的影响;为了能最大限度地利用路面附着能力,利用轮毂电机驱动力和制动力共同产生横摆力矩,并结合驱动模型切换提出了规则化转矩分配控制策略;通过数值仿真和硬件在环仿真开展了控制系统的性能分析。结果表明,所提出的基于区域极点配置的上层控制策略不仅能改善汽车的操纵稳定性,而且对轮胎侧偏刚度等参数不确定性具有较强的鲁棒性;同时,下层规则化转矩分配控制策略能确保在低附着路面可靠实现转矩分配。     

EPS与SASS的自校正集成控制仿真及试验研究

建立了汽车电动助力转向和半主动悬架集成控制的动力学模型,运用自校正控制理论设计了集成控制器.选择极点配置自校正控制,将闭环系统极点移到需要的位置上,并给出适当的控制律.自主开发出集成控制器,并用改进的可调阻尼减振器代替原车减振器,对某车型装车进行道路试验.仿真结果和试验结果验证了模型的正确性.表明该集成控制方法能够改善车辆的行驶平顺性和操纵稳定性.     

基于反馈控制的插电式混合动力汽车电池模块控制系统部件互换模块化的研究

为提高混合动力汽车电池模块控制系统的互换性和兼容性,本文中以插电式混合动力客车电池模块为研究对象,采用可有效保证系统稳定性和响应品质的反馈控制方法对电池模块闭环控制系统极点进行配置。在满足控制系统设计性能的约束条件下,基于BUSRTE工况对4种不同容量电池模块的控制器参数进行优化。结果表明,4种电池模块的控制系统具有良好的经济性和电量保持性,4种电池模块具有可互换性和对系统的兼容性,能满足部件互换模块化的要求。     

汽车电动助力转向系统

对目前汽车配置的助力转向系统做了简要比较,指出了机械液压和电子液压助力的缺点,介绍了电动助力转向系统的构成、工作原理、以及主要设计参数和控制特性。此系统的优点是节约能源,提高操作稳定性,是将来动力转向的发展趋势。     

双离合器式自动变速器液压系统分析与建模

分析设计液压系统油路及各液压阀工作状态,是开发双离合器式自动变速器控制系统的关键所在。在分析双离合器式自动变速器液压系统控制原理基础上,利用液压仿真软件AMESim对其液压控制系统中主要压力控制滑阀进行了建模仿真,阐述了系统中控制参数对液压系统的影响,为双离合器式自动变速器控制系统的设计和控制软件的开发奠定了基础。     

粘性液压联轴节特性分析与应用研究

系统地介绍了新型速度感应式限滑差速装置——粘性液压联轴节Visco-Lok，该装置存速度感应式限滑差速器基础上，在高转速差时通过加装剪切泵增大了限滑扭矩，提高了该工况下的牵引性，较好地实现了不同转速差下对车辆操纵稳定性、制动稳定性和牵引通过性的综合要求，并通过实车试验得到了验证。     

Matlab在控制系统稳定性判定中的应用研究

介绍了控制系统稳定性的概念,论述了利用极点判断法、特征值判断法、李雅普诺夫函数判断法等三种方法判定系统稳定性的原理,并用MATLAB具体实现了各种分析方法。     

丰田轿车ABS／TRAC防滑控制系统的电子控制

ＡＢＳ／ＴＲＡＣ防滑控制系统用于汽车 防止车轮抱死拖滑，提高和改善制动时的操作稳定性，简要介绍了丰田 轿车ＡＢＳ／ＴＲＡＣ防滑控制系统的基本组成，详细分析了该系统的电子控制原理。     

低附着弯道路面车辆制动力控制策略研究

分析了车辆ABS系统在弯道制动时存在的横向稳定性问题,提出了一种低附着弯道路面车辆制动力控制策略.它综合考虑车轮防抱死与车辆发生侧滑时所能承受的最大侧向力,根据两者所允许的最大制动力中较小值确定施加于车辆的制动力.所进行的数值仿真结果表明该控制方法能提高车辆在低附着弯道路面上的横向稳定性.     

Nonlinear Robust Control of Torque Converter Clutch Slip System for Passenger Vehicles Using Advanced Torque Estimation Algorithms

In this paper, a torque-estimation-based robust controller for passenger car torque converter clutch slip system is presented. The proposed robust controller uses only the measurements available from inexpensive sensors that are installed in current passenger vehicles for torque estimation and feedback control. A conventional full state observer along with a neural-network-based open-loop hydraulic actuator observer is designed to estimate the unknown driving load, and a neural-network-based turbine torque estimator considering the temperature of oil circulating the torque converter is developed for improved turbine torque estimation accuracy. The stability of the internal dynamics is also investigated, and the performance and robustness of the robust controller is validated by simulation studies.     

汽车稳定性控制系统的研究与仿真

在线性二自由度车辆模型基础上,采用直接横摆力矩控制方法,选取质心侧偏角和横摆角速度作为稳定性控制系统的主控变量,设计了三种具有针对性的基于滑模变结构理论的车辆操纵稳定性控制策略——质心侧偏角、横摆角速度和两者联合的滑模变结构控制。在Matlab,Simulink平台上,对三种汽车稳定性控制策略的具体应用进行仿真分析,验证了所设计稳定性控制算法的有效性和鲁棒性。     

Wheel Slip Control in Traction Control System for Vehicle Stability

Traction control systems are used to prevent wheel slippage and to maximize traction forces. This paper proposes a new scheme to enhance vehicle lateral stability with a traction control system during cornering and lane changes. This scheme controls wheel slip during cornering by varying the slip ratio as a function of the slip angle. It assumes that a traction control system with the engine throttle angle is used. The scheme is dynamically simulated with a model of front-wheel-driven passenger vehicles. Simulation results show that the proposed scheme is robust and superior to a conventional one, which is based upon fixed slip ratios, during cornering and lane changes.     

Wheel Slip Control in Traction Control System for Vehicle Stability

Traction control systems are used to prevent wheel slippage and to maximize traction forces. This paper proposes a new scheme to enhance vehicle lateral stability with a traction control system during cornering and lane changes. This scheme controls wheel slip during cornering by varying the slip ratio as a function of the slip angle. It assumes that a traction control system with the engine throttle angle is used. The scheme is dynamically simulated with a model of front-wheel-driven passenger vehicles. Simulation results show that the proposed scheme is robust and superior to a conventional one, which is based upon fixed slip ratios, during cornering and lane changes.     

The dynamic study of locomotives under saturated adhesion

In order to study the dynamic behaviours of locomotives under saturated adhesion, the stability and characteristics of stick–slip vibration are analysed using the concepts of mean and dynamic slip rates. The longitudinal vibration phenomenon of the wheelset when stick–slip occurs is put forward and its formation mechanism is made clear innovatively. The stick–slip vibration is a dynamic process between the stick and the slip states. The decreasing of mean and dynamic slip rates is conducive to its stability, which depends on the W/R adhesion damping. The torsion vibration of the driving system and the longitudinal vibration of the wheelset are coupled through the longitudinal tangential force when the wheelset alternates between the stick and the slip states. The longitudinal oscillation frequencies of the wheelset are integral multiples of the natural frequency of torsion vibration of the driving system. A train dynamic model integrated with an electromechanical and a control system is established to simulate the stick–slip vibration phenomenon under saturated adhesion to verify the theoretical analysis. The results show that increases of the longitudinal axle guidance stiffness and the motor suspension stiffness are beneficial to the stick–slip vibration stability and the locomotive's traction ability. The optimised matching of the longitudinal axle guidance stiffness and the motor suspension stiffness are helpful to avoid longitudinal resonance when the stick–slip vibration occurs.     

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.     

压力钢带式无级变速器技术降低油耗的潜能分析(一)

为降低压力钢带式无级变速(CVT)车型的燃油消耗,将研究重点放在对其内部不同损耗源的分析上,并认为最有可能降低损耗的部分是压力钢带式CVT的变速机构、液压驱动回路及其控制策略。根据研究结果指出,通过采取诸如滑移控制、改进的液压回路、分离离合器或启动-停止控制等措施,压力钢带式CVT仍具有较大的降低油耗的潜力;今后的工作应着重于扩大CVT滑移控制的工作区域及将此功能应用于生产实际中。。     

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.     

汽车防抱死制动系统的自抗扰控制研究

汽车防抱死制动系统（Anti-lock Braking System,ABS）的作用是确保汽车制动时行驶方向的稳定性、可靠性,但是目前仍存在非线性、时变性以及参数不确定性等问题。为保证汽车制动行驶过程中的操纵稳定性和安全性,进一步实现各工况下防抱死制动系统的优化控制,以影响整车稳定的变量滑移率为研究对象,分析所设计策略的控制效果。搭建汽车动力学模型、制动系统模型、轮胎模型和滑移率模型等主要模型,设计基于滑移率的ABS二阶非线性自抗扰控制器。运用MATLAB/Simulink软件对基于自抗扰控制（Active Disturbance Rejection Control,ADRC）的ABS制动过程和基于模糊PID控制的ABS制动过程进行仿真,对比研究最佳滑移率、载荷、水泥-冰对接路面、扰动等对制动过程中的轮速、车速以及滑移率等动态性征反映的稳定性和抗扰能力的影响,同时研究其对最终制动距离和最终制动时间反映的制动性能的影响。最后,将自抗扰控制器和模糊PID控制器装配于试验车辆的ABS,进行水泥路面和冰-水泥对接路面制动过程的实车试验。研究结果表明：基于二阶非线性自抗扰控制算法的ABS制动的最终制动距离和最终制动时间更短、制动效果更优,制动过程中的轮速、车速和滑移率在响应速度、稳定性和抗扰能力等方面均更佳;试验结果与仿真结果吻合,证明了仿真模型及其仿真结果的可行性和正确性。