The future of trucking technology in Brazil: results of a technology forecasting model

Abstract

The aim of this article is to identify a set of technological events related to the Brazilian truck fleet that are well placed hierarchically regarding their possibility of occurrence and pertinence for the horizon year of 2021. For this we propose and apply a Technology Forecasting Model for trucks (called TFM/Trucks) based on the Delphi technique, considering 28 technological events associated with six internal forecasting dimensions: safety, efficient use of energy and alternative fuels, materials technology, operational schemes, comfort and environment. The ranking of the technological events, considering hypothetical situations for analysis, indicate significant concern over the safety dimension, with four of the five events (passive safety and active safety) classified among the 10 events with the greatest chance of occurring and pertinence, irrespective of the panelists' degree of specialization. The environmental dimension, with respect to the predominance of electric powered trucks with lower level of atmospheric pollutants, was always in one of the first two positions, regardless of the situation studied. In the final ranking, the five best-classified events represented the dimensions of safety, environment, materials technology and comfort, with environment and passive safety predominating.     

超级电容纯电动重型牵引车参数匹配与控制策略

针对港口、码头、物流园区等场所节能环保用车的实际需求,首先提出一种以超级电容作为动力源的纯电动重型牵引车设计方案,实现动力总成选型与匹配理论计算;然后制定整车驱动控制策略,进而开发出超级电容纯电动重型牵引车原型样车;最后开展实车路测试验,检验原型样车的动力性、经济性指标.结果表明:空载最高车速达40 km·h-1,0～30 km·h-1加速时间仅需15 s,连续行驶里程达20 km;满载最高车速约为25 km· h-1,连续行驶里程约5 km,满足目标用户需要.     

牵引变压器状态监测技术研究概述

随着中国铁路客运向高速、货运向重载发展,电气化铁路设备的运行状态直接关系到电气化铁路的运输安全。文章从一次设备牵引变压器的状态维修体制角度,分析了牵引变压器状态监测对电气化铁路运输安全的影响和实现路线。     

Development of a model for an air brake system with leaks and a scheme for the estimation of the steady-state pushrod stroke

Brake systems in trucks are crucial for ensuring the safety of vehicles and passengers on the roadways. Most trucks in the USA are equipped with S-cam drum brake systems and they are sensitive to maintenance. Brake deficiencies such as leaks and out-of-adjustment of the pushrod are a major cause of accidents involving trucks. Leaks in the air brake systems drastically affect braking performance by decreasing the maximum attainable braking pressure and also increasing the time required to attain the same, thereby resulting in longer stopping distances. Out-of-adjustment of the pushrod leads to loss of braking torque even if no leaks are present in the air brake system. In this paper, we present a mathematical model for an air brake system in the presence of leaks, with a view towards developing a diagnostic system for the air brake system based on the models. Additionally, we present a scheme that estimates the severity of leak in terms of the mass flow rate of air leaking from the air brake system to the atmosphere. This scheme can be implemented using a simple look-up table. We also present a steady-state pushrod stroke estimation scheme, based on brake chamber pressure measurements in the absence of any leaks in the air brake system.     

重卡传动轴支撑角板载荷谱研究

为了提升重卡车型传动轴支撑角板的承载能力,基于传动轴支撑角板载荷试验,对不同载荷、不同路面条件下的传动轴支撑角板各向受力情况进行了研究分析。结果表明,传动轴支撑角板各向受力与路面类型、车速等有关,与车辆载荷关系不大。此外,文章还提出了提升支撑角板承载能力的相关改进意见和措施。     

我国长头重卡的现状与发展浅析

本文结合我国国情和重卡行业的变化综述了长头重卡的主要技术优势和其在国内市场存在的障碍,并分析了长头重卡重回市场的有利条件。     

重型汽车底盘测功机排放测试方法探讨

分析了国外研究机构关于重型汽车整车在底盘测功机上开展排放测试所采用的测试循环曲线和加载质量计算方式,探讨了国外研究机构在重型汽车测试方面的共同关注点,明确了重型汽车排放测试中测试曲线一般制订规则和加载质量的计算方法,并初步探讨了重型汽车整车排放测试对设备的基本要求,提出了制订我国重型汽车整车排放测试在循环曲线选择、加载质量计算方法方面的建议。     

上海绕城高速公路（同三段）重交通排水沥青路面应用实践

通过上海绕城高速公路（同三段）2008年整治工程进行了重交通排水沥青路面试验段实践,包括路面结构补强设计、排水系统设计、排水沥青混合料设计与性能试验、排水沥青面层施工与应用效果跟踪研究,初步表明排水沥青路面的使用对提高重交通道路雨天行车的安全性及舒适性具有良好的效果。经严格的材料选择与设计的开级配沥青混合料,可满足重交通道路使用性能要求。     

特重设备途经多座桥涵通行方案设计与实践

运输白鹤电厂重型设备到厂区需要通过121座桥涵,按传统方式对全部桥涵加固后通过,不仅投资大,工期长,而且延误发电经济损失巨大.通过反复论证,采用了直接通过,架临时钢桥和加固补强三种方案结合,经济、快速、安全将设备运到了厂区,为我国大件运输开创了一条可供参考的新途径.