Adaptive Noise Cancellation Method Used for Wheel Speed Signal of Integrate ABS/ASR System

The anti-lock braking system (ABS) and anti-slip regulation system(ASR) are the very i mportantparts of active safety systems used for modern vehi-cles . This two systems make up of commonintegratesystem ABS/ASR[1 ,2]. At present ,the main controlmethodin ABS/ASRis the logic threshold method.When getting the wheel speed signal ,ECUcomputesand applies control after comparing current signalwith the threshold[3 -5].Because of many reasons ,the wheel speed sig-nals sampled in ABS/ASRalw…     

Jetta-GTX轿车制动轮缸的压力变化率模型参数识别

根据ABS制动试验台的测量记录的制动管路压力变化数据,对Jetta-GTX轿车制动管路的压力增减变化特性进行了建模,通过对模型曲线和试验曲线的对比表明,利用最小二乘曲线拟合法直接识别得到模型的参数,从而可以较好地拟合ABS系统制动轮缸的压力变化。     

New Method of Road Surface Identification in Anti-Lock Braking System

Based on the vehicle-road dynamic model, the road characteristic parameter, which depends on different types of road surfaces, is introduced and a new method of road surface identification for automotive anti-lock braking system (ABS) is proposed. According to the characteristics of vehicle-road dynamic model, a simple math resolution method of the model‘s factors is established. Only using the information of wheel speed, the vehicle reference velocity and the wheel slip ratio are estimated real-timely. And based on the wheel dynamic model, the road characteristic parameter is determined to identify the road surface for the determination of thresholds of ABS regulative parameters. With this new method, the road surface identification can be accurately obtained and calculation time is short that it can meet the ABS real time control need, and it also improves the performance of ABS.     

基于MC9S12DP256的汽车ABS数据采集系统设计

设计了基于MC9S12DP256单片机的汽车ABS数据采集系统;详细介绍了该系统的硬件电路以及系统软件设计.大量的ABS实车实验证明:该数据采集系统工作性能良好,可靠性高.采集数据的精度完全可以满足汽车ABS系统的要求.     

Experiment Research on Fine Regulation of Wheel Cylinder Pressure Using PWM Technology

A test bench of ABS/ASR integrated hydraulic system is developed by using pulse-width modulation （PWM） technology. The effective duty ratio range of ABS outlet valve has been tested in PWM control. With 50 Hz carrier wave frequency, the tests are performed to determine the correspondence between duty ratio and the wheel cylinder pressure variation. The duty ratio range of ABS outlet valve in PWM control is determined and an experimental model of pressure reduction velocity （PRV） of wheel cylinder using PWM control is established. By comparison and test of the experimental model and realization of controlling the duty ratio of ABS outlet valves, the fine regulation of wheel cylinder PRV is realized in the working of ABS/ASR braking regulation, which is important and valuable to the improvement of the ABS/ASR controlling effect.     

Vehicle Dynamics Modeling and Simulation for ACC

A 7 degree-of-freedom (DOF) 4 wheels vehicle dynamics model based on Matlab-Simulink is established,and 7 DOF vehicle dynamics equations in the form of nonlinear state-space standards are given.The characters of the electronic throttle and the active braking system have been analyzed.And the electronic throttle model and the active braking system model are built according to the test results respectively.Off-line simulation results indicate that the model is suitable for the vehicle adaptive cruise control ...     

Estimation of Vehicle Speed Based on Wheel Speeds from ASR System in Four-Wheel Drive Vehicles

Three major methods currently in the use of determining vehicle speed based on wheel speeds,the minimum wheel speed,minimum wheel speed corrected by slope method and the Kalman filter method,are analyzed,with merits and defects of each approach stated. Through simulations,the Kalman filter method based on minimum wheel speed shows improved accuracy,in addition to better adaptivity to vehicle reference speed. It also can be used to acceleration ship regulation (ASR) in part-time four-wheel drive vehicles.     

基于ABS的ABS/ASR集成液压系统设计

介绍一种基于JETTA GTX轿车ABS液压系统的ABS／ASR集成液压系统改造方案，该ABS／ASR集成液压系统在原有ABS液压系统的基础上增加较少的液压元件实现全部ABS功能和ASR制动干预控制功能，改造后的集成系统工作可靠，不影响原有的常规制动和ABS制动过程。     

汽车ABS电机故障诊断

详细论述了实现汽车ABS电机故障诊断的基本原理,方法和硬件电路设计,并将其应用于自主开发的ABS故障诊断系统中,经实车试验,效果良好.     

国外高速拖拉机的发展研究

简述了为适应高速道路运输和田间作业两方面的需要,研制和发展高速拖拉机的必要性;介绍了高速拖拉机悬架系统的配置、传动系统的改进、制动系统的强化以及目前所面临的问题等;最后就国产拖拉机运输速度的适当提高提出了一些可行性的建议。