汽车轮胎胎面磨损程度检测系统

汽车轮胎的安全性直接关乎交通安全和乘客的出行安全, 轮胎异常磨损容易导致爆胎, 严重磨损的轮胎时刻威胁着乘客的生命安全, 汽车在道路上飞驰的过程中主要磨损的是轮胎的胎面, 因此实现自动化的轮胎磨损检测很有必要. 本研究借助Visual Studio 2017开发平台, 采用C++编程, 使用OpenCV计算机视觉库的API接口结合自主编程的处理顺序, 实现了对轮胎图像的自动采集传输和处理分析, 该系统能精准提取轮胎胎面图像, 并通过分析胎面图像的灰度共生矩阵的特征值判定轮胎的磨损程度, 实现了针对轮胎胎面磨损的自动化检测系统.     

单轮电机失效时四轮轮毂电动汽车各驱动模式转向特性研究

文章在对轮胎侧偏特性和轮胎力研究的基础上,提出了四轮轮毂电动汽车四种驱动模式的转向力矩分配问题;通过数学分析,将此问题转化为一个有约束条件的最优化求解问题,接着使用MATLAB优化工具箱,并采用有效集算法对此优化问题进行求解,最终解决了单轮电机失效时四种驱动模式的选择问题,为改善单轮电机失效时四轮轮毂电动汽车的转向特性,防止车辆侧滑失稳提供了理论依据;最后采用汽车动力学仿真软件TESIS DYNAware对所提理论的正确性进行了仿真验证。     

铁水包车多轴转向机构运动学分析与优化

多轴转向车辆转向机构必须协调各转向轮转角,以满足阿克曼转向原理,才能减少轮胎磨损,提高转向性能.建立了液压平板铁水包车多轴转向机构的运动学分析模型,对转向机构进行了运动学分析,分析结果表明该转向机构与阿克曼原理偏差较大.根据阿克曼转向原理和梯形转向机构特点,提出了改进的多轴转向机构方案,新的转向机构优化仿真结果表明,方案能够更好的协调转向轮转角,降低轮胎磨损,改进的转向机构比原转向机构方案能够更好的满足转向原理,结构更加简单.     

车辆数据在智慧服务中的应用

在“软件定义汽车,数据驱动汽车”这一时代浪潮驱动下,汽车产业开始朝着智能网联方向发展。智能网联汽车在运行时会产生大量的数据,这些数据记录了车辆运行时的状态、路侧的信息以及驾驶员相关的操作痕迹等,并且描绘了车辆和车主的画像。挖掘这些数据的内容,能洞察车辆当前是否正常运行,了解车主在驾车时的需求,为车主提供更智能和更方便的服务。基于此,本文对车辆数据在智慧服务中的应用进行了阐述。     

千里之行始于“足”下——爱车轮胎养护(一)

轮胎是车之足,是行车的基础,是车中主要被磨损和消耗的部件之一,也是车中使用环境最恶劣的部件,因为它要忍受不同的路面、温度和危险。而因为它的故障所导致的麻烦甚至危险(比如爆胎)却也是汽车安全中最主要的不确定因素。轮胎作为车辆最容易磨损的部件之一,它的使用寿命跟其本身的质量、车辆状况、车辆驾驶人的驾车习惯都有很大关系。现在的有车一族都比较注重车辆的外在保养,关心的是车子看起来靓不靓,椅套跟抱枕摸起来舒不舒服。但是,有多少人知道这轮胎该怎么保养呢?甚至有些人有没有想过轮胎其实也是需要您的定期关爱呢?希望通过本期的介绍,能够帮助大家对轮胎的养护有个初步的认识,提高广大车主对轮胎的重视程度,以确保您爱车的轮胎能得到及时的养护。下面我们就告诉大家如何保养才能延长轮胎的使用寿命,以及使轮胎总保持最佳的性能状况。     

基于阿克曼原理的4WID/4WIS汽车循迹控制研究

针对四轮独立驱动、独立转向汽车循迹控制精度和转向稳定性兼容问题,同时考虑减小轮胎磨损,延长轮胎使用寿命,本文基于阿克曼转向原理和RBF神经网络PID理论,提出了一种自适应的循迹控制方法.首先,设计了基于RBF神经网络PID理论的自适应转向控制器,用于控制前内轮转角,保证循迹精度;其次,后内轮以减小质心侧偏角为目标进行辅助转向,保证转向稳定性;接着,基于阿克曼转向原理,确定外轮转角,保证各轮侧偏力分配合理;最后,采用同一瞬心法,确定各车轮转速,以减小轮胎滑动率.本文搭建了CarSim和MATLAB/Simulink联合仿真平台,进行了仿真实验,结果表明：本文提出的循迹控制方法,不仅能获得较小的循迹偏差和质心侧偏角,保证了足够的循迹控制精度和转向稳定性,同时还减小了轮胎滑动率,有利于减小轮胎的磨耗.     

基于有限元的轮胎自激振动时频分析

研究汽车轮胎减少磨损,延长使用寿命的问题,轮胎多边形磨损与胎面质量块的侧向自激振动密切相关.了解产生自激振动的速度区间以及胎面与地面的摩擦状态就显得十分重要.因此建立了轮胎一地面系统的理论模型,引入符合轮胎橡胶摩擦规律的摩擦曲线.运用有限元软件,建立子轮胎与地面有限元模型,导入上述摩擦曲线,分析了位移时间历程和位移速度相平面图,发现了容易产生自激振动的速度区间.选择三种特征车速进行仿真.结果证明通过研究可以减少轮胎的磨损量,延长寿命,为今后轮胎多边形磨损正确建模有参考价值.     

浅谈汽车四轮定位检测与调整技术

四轮定位对汽车的正常行驶起着十分重要的作用。对汽车四轮定位参数进行检测和调整,不仅能确保汽车的正常行驶,还能延长轮胎的使用寿命,同时节省油耗。重点研究了汽车四轮定位的检测方法和调整技术。     

基于参数估计的半挂汽车列车稳定性控制研究

车辆参数估计是半挂汽车列车稳定性控制研究的关键,通过递推最小二乘法（RLS）估计整车质量和轮胎侧偏刚度,进而获取挂车横摆转动惯量,将估计的车辆参数应用于稳定性控制系统,修正控制系统参数.基于商用车动力学仿真软件TruckSim建立了某半挂汽车列车的非线性整车仿真模型,在Matlab/Simulink中设计建立了稳定性控制逻辑和参考响应模型,通过TruckSim-Simulink的联合仿真对控制方案进行了验证分析.结果表明,基于名义参数设计的控制系统受载重变化的影响较大,而带有参数估计的控制系统由于能够对控制参数进行修正,可以较好地适应载运工况的变化,受载运工况的影响较小.     

刚柔耦合重型汽车建模及通过连续减速带的平顺性分析

建立了考虑车架柔性的刚柔耦合重型汽车整车模型,通过与刚性车对比,验证了所建刚柔耦合车辆模型的正确性.依据实际需求建立了三组连续减速带模型,以车身垂向加速度和各轮垂向轮胎力为评价指标,分析车辆行驶速度、减速带高度和宽度对汽车行驶平顺性的影响.研究表明,减速带的高度与车身垂向加速度和垂向轮胎力成正比,减速带宽度与车身垂向加速度和垂向轮胎力成反比,对于限速60 km/h的道路,宽度为600 mm,高度为8 mm的减速带能起到良好的限速效果,同时还能保证车辆行驶的平顺性.     

A decision support system for improved resource planning and truck routing at logistic nodes

In this paper, we present an innovative decision support system that simultaneously provides predictive analytics to logistic nodes as well as to collaborating truck companies. Logistic nodes, such as container terminals, container depots or container loading facilities, face heavy workloads through a large number of truck arrivals during peak times. At the same time, truck companies suffer from augmented waiting times. The proposed system provides forecasted truck arrival rates to the nodes and predicted truck gate waiting times at the nodes to the truck companies based on historical data, economic and environmental impact factors. Based on the expected workloads, the node personnel and machinery can be planned more efficiently. Truck companies can adjust their route planning in order to minimize waiting times. Consequently, both sides benefit from reduced truck waiting times while reducing traffic congestion and air pollution. We suggest a flexible cloud based service that incorporates an advanced forecasting engine based on artificial intelligence capable of providing individual predictions for users on all planning levels. In a case study we report forecasting results obtained for the truck waiting times at an empty container depot using artificial neural networks.     

The ergonomics of different tyres and tyre pressure during wheelchair propulsion

It is believed that the newer solid tyres on wheelchairs perform as well as pneumatic tyres along with less cost and time for maintenance. The questions are: (1) do solid tyres perform as well as pneumatic tyres and (2) what is the critical level of pneumatic tyre pressure before wheeling efficiency decreases? Part one measured the rolling resistance differences of five commonly used wheelchair tyres (three pneumatic and two solid) under four different tyre pressures (100, 75, 50 and 25 of inflation). Part two measured the oxygen consumption in 15 participants with paraplegia, during wheelchair propulsion, comparing the same four levels of tyre inflation. The solid tyres performed worse than all three pneumatic tyres even when tyres were under-inflated to 25% of tyre pressure. Two of the pneumatic tyres showed significant decreases in rolling between 100 and 50%, but there were no significant differences in rolling distance between 100 and 75% pressure. The physiological study showed that energy expenditure increased significantly at 50% of tyre-inflation. Health care facilities are finding ways to decrease cost by using solid tyres on all wheelchairs. This study shows that benefits to clients and staff using pneumatic tyres far outweigh the minimal cost in time to maintain adequate tyre inflation.     

The ergonomics of different tyres and tyre pressure during wheelchair propulsion

It is believed that the newer solid tyres on wheelchairs perform as well as pneumatic tyres along with less cost and time for maintenance. The questions are: (1) do solid tyres perform as well as pneumatic tyres and (2) what is the critical level of pneumatic tyre pressure before wheeling efficiency decreases? Part one measured the rolling resistance differences of five commonly used wheelchair tyres (three pneumatic and two solid) under four different tyre pressures (100, 75, 50 and 25 of inflation). Part two measured the oxygen consumption in 15 participants with paraplegia, during wheelchair propulsion, comparing the same four levels of tyre inflation. The solid tyres performed worse than all three pneumatic tyres even when tyres were under-inflated to 25% of tyre pressure. Two of the pneumatic tyres showed significant decreases in rolling between 100 and 50%, but there were no significant differences in rolling distance between 100 and 75% pressure. The physiological study showed that energy expenditure increased significantly at 50% of tyre-inflation. Health care facilities are finding ways to decrease cost by using solid tyres on all wheelchairs. This study shows that benefits to clients and staff using pneumatic tyres far outweigh the minimal cost in time to maintain adequate tyre inflation.     

Truck schedule recovery for solid waste collection in Porto Alegre, Brazil

This paper considers a truck schedule recovery problem in the context of solid waste collection in the city of Porto Alegre, Brazil. When a truck on a scheduled trip breaks down, a backup truck needs to be selected to serve the cargo on that trip and other trucks might be rescheduled in order to gain the minimum operating and delay costs. The problem consists of designing, in the case of a severe disruption in a trip, new schedules taking into account the existing trucks in the system and a set of unfinished and not initiated collection trips, on which the trucks collect the solid waste in fixed routes and empty the loads in one of the several operational recycling facilities. The main objective is to minimize the total distances traveled and delay costs, as well as to obtain balanced assignments of truck unloads into the recycling facilities, due to the social benefits of the solid waste program. We modeled the problem as a mixed-integer linear problem and used CPLEX to solve it. Finally, computational experiments are conducted on real-world data. The results show that our approach successfully reduces the distances traveled and delays, simultaneously balancing the number of trucks unloading at each recycling facility, in comparison with the current manual strategy.     

A Multicommodity Integrated Freight Origin–destination Synthesis Model

This paper introduces a multi-commodity, single (generic) vehicle formulation of freight ODS model that combines a commodity-based model to estimate loaded truck trips and a complementary model of empty trips. This integration is important because explicit modeling of empty trips—that account for 30% to 40% of total truck trips—is required to avoid significant errors in the estimation of the directional traffic. The formulation is then applied to a case study. Two cases of the proposed model are studied. The first one uses total traffic in the estimation; while the second one is based on loaded and empty traffic. The results conclusively show that the models that consider an empty trip submodel significantly outperform the model that does not in their ability to replicate the observed traffic counts. The comparison between the results from the multi-commodity ODS and the single commodity ODS previously developed by the authors indicates that the multi-commodity formulation brings about substantial reductions in the error associated with the estimation of observed traffic counts. These reductions, in the order of 20% for empty traffic and 40% for loaded and total traffic, seem larger than the spurious improvement to be expected from the increased number of parameters, suggesting that the multi-commodity ODS formulation performs better. The results also show some minor improvements in the ability of the multi-commodity ODS formulation to estimate the OD matrices. In terms of the model's ability to correctly estimate the “true” value of the parameters of the models used, i.e., the parameter values estimated by calibrating the model directly from the OD data, it was found that the multicommodity ODS procedure is able to provide fairly good estimates Noortman and van Es's model parameters, though the parameters of the gravity models that came out to be quite different than the “true” values. The overall assessment of the formulation introduced here is that it represents a solid improvement with respect to comparable techniques.     

一种自适应识别RFID标签的方法

铁路标签分为机车标签和货车标签,两种标签被读写器发射的射频能量激活后,将连续不断、周而复始地返回标签中的数据帧给读写器,但两种标签返回的信号波形是不同的;利用机车标签帧头(特征值为0xE6D)与货车标签帧头(特征值为0x555555A)的不同,可转入不同的解码程序,达到自适应地识别出机车标签数据或货车标签数据;当列车运动时,货车标签返回给读写器的信号受多径效应的影响,出现衰落现象,使读写器不能正确识别标签数据,而且标签信号出现衰落的时间是随机的;利用同步特征信号可以采集到残缺的数据,并利用三帧残缺的数据拼接出一帧完整的标签数据。即使列车速度达到80km/h,也能正确识别出标签数据。     

多媒体技术在无人值守计量系统中的应用

随着计算机科学技术、信息技术的发展,越来越多的技术手段被应用于各个行业,提高生产力、节约资源也随之带来可观的经济效益和社会效益．与此同时多媒体技术的应用也得到了飞速的发展。介绍多媒体技术在远程无人值守计量系统中涉及的语音对讲、视频监控的实现及其意义。     

基于嵌入式系统的机器人视觉定位系统的研究

采用嵌入式EPXA10为核心,以污水车自动泄放机器人为应用对象,本文介绍一种双目视觉定位系统。提出一种利用模糊算法进行目标图像的边缘检测,并结合双目视觉定位的算法实现机器视觉定位的方法。针对污水泄放机器人的工作特点,采用主动寻找特殊图的方法,达到快速准确对目标跟踪定位的目的,完成对污水车泄放口的三维定位,机器人根据定位坐标可以准确地接通污水泄放管,快速把污水泄放到池中。     

异步电机功率因数自动控制的研究

本文给出了一种异步电机功率因数自动控制的实施方案,并在不同负载下进行了实验,实验结果表明,该方法在轻空载时具有明显的节能效果。