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…     

Electronic Brake Force Distribution Control Methods of ABS Equipped Vehicles During Cornering Braking

Based on the dynamics of ABS-equipped vehicles during cornering braking, the electronic brake-force distribution (EBD) control methods of ABS-equipped vehicles during cornering braking are proposed. According to the dynamics and the tire model under tire adhesion limit, the stability acceptance criteria of vehicles during cornering braking are proposed. According to the stability acceptance criteria and the ABS control, the EBD control methods of ABS-equipped vehicles during cornering braking are implemented by adjusting the threshold values of tires slip independently. The vehicle states during cornering braking at two typical initial velocities of the vehicle are analyzed by the EBD control methods, whose results indicate the EBD control methods can improve the braking performances of the vehicle during cornering braking comparing with the ABS 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.     

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.     

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.     

车辆驾驶员辅助系统中基于运动模型的前车最优跟随控制

为解决驾驶员辅助系统在前车跟随控制中车距与车速误差不易同步收敛的问题,建立考虑主车对期望加速度动态响应的主车与前车运动模型,以对前车跟随控制提供模型参考。基于主车实际运动与理想前车跟随行驶间的偏差建立前车跟随误差模型,并用线性二次型调节器求解最优期望加速度控制序列,以作为前车跟随控制中主车运动参数控制的输出。为考虑在实车控制中车辆及环境参数发生变化的可能,在前车跟随误差模型中引入车距与车速误差累积项以使线性二次型调节器具有积分控制功能,以在实际车辆与理想模型发生偏差时仍可进行有效控制。仿真对比及实车试验证明,基于运动模型的前车跟随控制可使主车车距与车速误差同步收敛并有效减少主车达到稳态前车跟随行驶的时间,同时易于在实车控制中展开应用。     

Robust lane recognition for structured road based on monocular vision

A robust lane detection and tracking system based on monocular vision is presented in this paper.First,the lane detection algorithm can transform raw images into top view images by inverse perspective mapping(IPM),and detect both inner sides of the lane accurately from the top view images.Then the system will turn to lane tracking procedures to extract the lane according to the information of last frame.If it fails to track the lane,lane detection will be triggered again until the true lane is found.In this system,θ-oriented Hough transform is applied to extract candidate lane markers,and a geometrical analysis of the lane candidates is proposed to remove the outliers.Additionally,vanishing point and region of interest(ROI)dynamically planning are used to enhance the accuracy and efficiency.The system was tested under various road conditions,and the result turned out to be robust and reliable.     

汽车前向主动报警/避撞策略

为了准确地判断当前工况的危险程度,在充分利用已知车间运动信息的基础上,提出了避撞时间余量Tbuffer的概念。基于Tbuffer指标设计了一种适用于不同驾驶员避撞特性的分级报警/避撞算法,并且通过声光报警及主动制动帮助驾驶员实现有效避撞。最后将本文算法与其他4种算法在3种工况下进行了对比仿真试验,结果表明:所提出的主动避撞策略符合驾驶员避撞特性,有效地提高了汽车的主动安全性。     

液压ABS系统研究进展与发展方向

该文对目前国内关于汽车制动防抱系统的研究情况做了介绍，对制动防抱系统的发展趋势进行了展望。