SAC和其他粗集料断级配的矿料级配设计方法

详细介绍了SAC和其他粗集料断级配沥青混凝土的矿料级配设计原理和计算方法。通常粗集料的级配是一个幂函数,有40％左右的孔隙率;细集料是另一个幂函数,是一个很密实的级配。两者结合在一起,组成一个以粗集料为主体的密实式中断级配。     

加强汽车兵礼仪修养，做文明行车人

对一个社会来说,礼仪是一个国家社会文明程度、道德风尚和生活习惯的反映。对一支军队来说,礼仪是其作为文明之师的文明程度和精神面貌的反映．是作风纪律状况的重要标志。对一个军人来说,礼仪则是其思想道德水平、文化修养、交往能力的外在表现。对于一个汽车兵来说,礼仪更是展示文明之师形象,确保文明出行、安全畅通的必然要求。     

会议精华共享 2011《汽车与配件》-平安证券新能源汽车研讨会系列报告（一） 新能源汽车——历史的选择

新能源汽车是属于一个历史的选择,是一个必须要面对的事实。而政策和技术是决定这个行业发展的两大驱动因素。     

润滑油行业洗牌的征兆之促销见底

行业或者企业每一个阶段的蜕变,对于一个行业或者企业者来说,都是一次不小的冲击和挑战,有的企业成长了、发展了、壮大了,也有企业被淘汰了或者出局了。当一种企业瓶颈扩散为一个行业瓶颈,势必将会促进行业洗牌。这也是一个行业正常发展必须经历的成长轨迹。企业能否顺利的通过每一次行业升级,脱颖而出的成为行业新一轮的竞争力企业,也将影响洗牌后行业的新秩序。每一个企业都将是这轮洗牌的导演和     

浅谈公路养护与管理

公路是国家的基础设施,也是衡量一个国家现代化水平的重要标志之一。目前,各级公路维修养护的管理与发展,正处在一个不断探索和演变的阶段。如何根据公路养护管理的现状,突出公路养护管理中的作用,真正实现既保证养护维修质量,又减少养护成本支出的目标,是一个值得研究和探讨的课题。     

哥伦比亚的故事(下)

内巴——迪亚哥的家从巴格达南下有两条路,一条在西部,途经我们一个月前曾经去过的咖啡金三角地区,另外一条在中部,途经内巴(Neiva),那边有一个沙漠,安帝和我都很感兴趣。印象中,哥伦比亚到处是热带雨林和青山绿水,这个沙漠是啥样的呢?我们选择内巴的另外一个原因是我们离开     

梁玉鹏一手打造丹桂轩饮食王国

这是一个充满理想、充满挑战和机遇的年代；这是一片充满希望和生机，创造一个又一个东方神话的土地。今年深圳将迎来经济特区成立30周年的纪念日。     

好雨知时节——雅马哈在湖南哨然发力

湖南是一个非常理想的摩托车市场。 湖南处在中国中部一个非常有利的地理位置,且全省山区和丘陵地貌占全省总面积的绝大部分。加上其丰富的自然资源,素有鱼米之乡的美誉。经济发展水平处在全国各省、市、自治区的前列,这就决定了湖南是一个理想的摩托车市场。更是一个摩托车消费大省。曾几何时,     

掌门老陕——华晨掌门祁玉民印象

一个品牌的成长和人的成长一样,需要岁月的磨练。岁月就像一个筛子,可以筛掉浮躁和懵懂,而沉淀下来的则是自信和从容。     

摩托车及发动机中的匹配问题

摩托车及发动机的设计和匹配是一个综合工程,任何一个细节都有可能导致其寿命的变化,本文是笔者多年工作中遇到的相关问题及心得,供读者参考.     

异形钢独塔斜拉桥设计

洞口县平溪江大桥为主跨100 m的异形钢独塔斜拉桥,跨越洞口县平溪江。该桥为双索面,塔梁墩固结体系;主梁为两侧单箱单室P-K预应力混凝土混凝土箱形梁,桥梁全宽34.6 m。拉索为平行钢丝斜拉索,冷铸锚。主塔为异形钢箱结构,拉索通过钢锚箱锚固于主塔上。主跨跨越平溪江,采用悬臂浇筑法施工;锚跨位于岸上,采用现浇支架施工。     

Realization of pmp-based control for hybrid electric vehicles in a backward-looking simulation

Optimal control is generally not possible without information about the future coming up, and it is not easy to obtain an optimal solution even though the information is given a priori. In this paper, a control concept based on Pontryagin’s Minimum Principle (PMP) is introduced as an efficient solution to generate an optimal control trajectory for Hybrid Electric Vehicles (HVEs) when the performance of the vehicles is evaluated on scheduled driving cycles at a simulation level. The main idea of the control concept is to minimize Hamiltonian, which is interpreted as equivalent fuel consumption, and the Hamiltonian is characterized by a co-state, which is interpreted as a weighting factor for the electrical usage. A key aspect of the control problem is that an appropriate initial condition of the co-state is required to satisfy the boundary condition of the problem. In this study, techniques to calculate the Hamiltonian in different hybrid configurations are introduced, and a methodology to look for the initial condition of the co-state is studied, so that the controller is able to realize a desired State Of Charge (SOC) trajectory. To address the issue, we utilize a shooting method with multiple initial conditions based on the concept of the Newton-Raphson method, and all these techniques are realized in a backward looking simulator. The simulation results show that the PMP-based control is a very efficient approach to produce the optimal control trajectory, and the performance is compared to the optimal solution solved by Dynamic Programming (DP).     

轿车用转向节试验方法

为了减少转向节作为安全件在客户使用过程中发生疲劳及冲击断裂的风险,文章对轿车用转向节设计验证方法进行研究,采用台架疲劳试验和台架冲击试验的方法对某轿车用转向节进行了验讧。通过试验,加强了样件薄弱处的设计并对不合格样件进行了整改。经批量市场考验,通过台架疲劳及冲击验证的转向节在客户使用过程中减少了断裂的风险,提高了产品的质量,具有非常高的使用价值。,     

Torque ripple minimization control of permanent magnet synchronous motors for EPS applications

This paper identifies a control method used to reduce torque ripple of a permanent magnet synchronous motor (PMSM) for an electric power steering (EPS) system. NVH (Noise Vibration Harshness) is important for safe and convenient driving. Vibration caused by motor torque is a problem in column type EPS systems. Maintaining a very low torque ripple is one solution that allows for smoother steering. Theoretically, it is possible to design and drive the motor without torque ripple. However, in reality, a PMSM system torque ripple is caused by the motor itself (saturation in the iron core and EMF distortion) and the imperfect driver. This paper analyzes torque ripple of a PMSM system, and an advanced PMSM control method for the column typed EPS system is presented. Results of the analysis indicate that the compensation current is needed in order to minimize torque ripple when a PMSM is driven.     

面向交通枢纽的车辆三维真实感实时仿真

为分析和解决城市交通拥挤问题并提高城市道路利用率提供可行的途径,提出了一种面向交通枢纽的车辆运行仿真方法,通过场景、道路与车辆的三维动态建模,实现交通枢纽交通状况的实时真实感仿真.首先,提出了基于道路关键点连接网络模型表示交通枢纽的通行道路.其次,基于粒子系统实现车辆的动态运行实时仿真,并采用基于空间剖分的车辆碰撞检测方法对车辆运动控制算法进行了优化.最终,通过对路段的动态观测和反馈机制实现车辆行驶路线的规划和调度.实验结果表明,本文提出的方法可以生动直观地呈现实际路面的交通状况,并且能以较为流畅的帧速率实现交通场景的动态仿真.     

Analytical study to estimate the performance of the Power Shift Drive (PSD) Axle for a forklift

In this study, a new concept for a power delivery system is developed. Power Shift Drive (PSD) Axle vehicle modeling and dynamic movement analysis are performed via simulation. The dynamic vehicle model is constructed from data obtained from the derived equation, considering the specific characteristics of each part. The model is composed of a torque converter, a gear box, a differential, hub reduction and an engine, which is the power source of the 1st forward and reverse PSD-Axle. By unifying the mathematical equations for each component, a mathematical model of the 1st forward gear is derived. The system dynamic model is created using MATLAB/Simulink based on the mathematical model. Simulation is carried out using Simulink to estimate the dynamic behavior of the PSD-Axle. In addition, the dynamo test result is used to verify the model. Finally, a successful model is created. This study will be used to establish the basic conceptual design for the PSD-Axle multi-gear system.     

基于机器视觉的球笼保持架窗口位置检测方法

介绍了一种基于视觉检测技术的球笼保持架窗口位置在线检测方法.采用具有独特双光源照明的成像系统的同时获取了窗口边缘和基准面的图像信息,以VC++为平台对数字图像信息进行处理和分析,频域高斯滤波完成图像去噪后,采用形态学边缘检测算法获得窗口边缘点和基准点,利用两直线的平行关系开展最小二乘直线拟合确定窗口边缘位置.实际应用证明该系统稳定可靠,检测效率高,具有良好的应用前景.     

基于模糊控制的纯电动轿车整车优化控制策略

将纯电动汽车分为3种行驶模式:常规模式、经济模式和动力模式.动力模式注重提高车辆的动力性,经济模式注重延长车辆的行驶里程,常规模式则为两者的折中.文中利用模糊控制方法设计了整车控制策略,利用MATLAB软件进行了仿真,开发了整车控制器并进行了相关试验,结果表明,该策略对于提高电动汽车性能起到了良好的作用.