排水型高速船的耐波性试验与理论研究

对一艘30m级、Fr=0.871的高速巡逻艇在迎浪规则波中的纵向运动进行了耐波性试验，测量了该艇在不同航速下的升沉、纵摇、垂向加速度幅值响应曲线。同时，应用切片理论（STF法）对该艇在规则波中的纵向运动响应进行了理论计算、试验与理论计算结果比较进一步证实，对方尾排水型高速船，切片理论的计算结果具有相当的准确性，可用于高速单体船的方案设计中，应用文中运动频率响应曲线的试验和数值计算结果，进一步预报了该艇型在实际海区的耐波性能。     

机床再生型切削颤振系统稳定性极限预测

推导了机床再生型切削颤振系统极限切削宽度随主轴转速变化的计算公式。提出了机床切削系统稳定性极限预测方法，就实验系统的切削稳定性极限进行了预测。预测结果与实验结果对比，最小极限切削宽度的预测误差为32％，与其相对应的主轴转速的预测平均误差小于。     

高速客车转向架悬挂参数分析

为了全面考察转向架悬挂参数对高速客车行车安全性和乘坐舒适性的影响规律,为高速客车转向架悬挂参数的合理选取提供理论依据,首先从时域内分析了一、二系悬挂参数对高速客车动力学性能的影响,然后从频域内分析了二系悬挂参数对车体振动模态的影响.仿真计算与分析结果表明:合理设置一系纵向和横向定位刚度和二系抗蛇行减振器结构阻尼参数即可基本实现转向架较高的临界速度;减小二系横向刚度而适当增大二系横向阻尼可提高高速客车的横向平稳性;为了改善高速客车的垂向平稳性,一、二系垂向减振器阻尼都不宜选取过大.     

轮胎临界速度影响因素分析

分析了轮胎临界速度的影响因素，在合理假设的基础上，根据振动理论建立了轮胎使用的力学模型，得出轮胎变形恢复时间与其有效质量之间的关系。结果发现影响轮胎临界速度的使用因素包括负荷、充气压力、径向变形和胎面磨损量，载荷一定时，提高轮胎充气压力，充气压力一定时，减轻载荷都有利于提高轮胎使用的临界速度。分析结果与轮胎的实际应用情况相符，说明该模型可行。     

客运专线动车组运用计划的计算机编制

根据动车组运用规则，建立了动车组运用计划整数规划模型．为降低求解的复杂性，将动车组运用计划编制问题转化为交路段生成和基于交路段的交路生成两个问题分步求解．用多起点搜索和交路段互换的方法，使求解结果在有效性和均衡性上得以优化．实际编制实验表明了模型和算法的有效性．     

单轴加速度计在轴功率测量中的应用研究

介绍了一种利用重力加速度测量旋转机械主轴转速的方法,通过单轴加速度计与计算机技术的融合,实现了轴转速的测量,该方法提供了轴输出功率测量的一体化方案,安装操作简单成本低廉,能够适应较为复杂的测量环境要求。     

Modification of the Highway Capacity Manual two‐lane highway analysis procedure for Spanish conditions

The US Highway Capacity Manual (HCM) methodology is used in Spain to evaluate traffic operation and quality of service. The effect of passing manoeuvre on two‐lane highway operational performance is considered through adjustment factors to average travel speeds and percent time spent following. The procedure is largely based on simulations in TWOPAS and passing behaviours observed during US calibrations in the 1970s. It is not clear whether US driving behaviour and vehicles' performance are comparable with Spanish conditions. The objective of this research is to adapt the HCM 2010 methodology to Spanish driver behaviour, for base conditions (i.e. no passing restrictions). To do so, TWOPAS was calibrated and validated based on current Spanish passing field data. The calibration used a genetic algorithm. The case study included an ideal two‐lane highway with varying directional traffic flow rate, directional split and percentage of trucks. The updated methodology for base conditions is simpler than the current HCM 2010 and does not rely on interpolation from tables. Copyright © 2016 John Wiley & Sons, Ltd.     

The speed control effect of highway tunnel sidewall markings based on color and temporal frequency

The low‐luminance monotonous environment in the middle section of highway tunnels offers few reference points and is prone to cause severe visual illusion. Thus, drivers tend to underestimate their driving speed, which can induce speeding behaviors that result in rear‐end collisions. Therefore, discovering low‐cost methods of traffic engineering that reduce this visual illusion and ensure a steady driving speed is an important challenge for current highway tunnel operations. This study analyzes the effects of sidewall markings in typical highway tunnels, specifically observing how their colors and temporal frequencies affect the driver's speed perception in a low‐luminance condition. A three‐dimensional model of the middle section of highway tunnels was built in a driving simulator. Psychophysical tests of speed perception were carried out by the method of limits. The precision of the simulation model was then checked by comparing the results to field test data. The simulation tests studied the stimulus of subjectively equal speed and reaction time in relation to sidewall markings in different colors (red–white combined, yellow–white combined, and blue–white combined). Furthermore, based on the optimal color, the effects of sidewall marking with different temporal frequencies (0.4, 0.8, 1.2, 2, 4, 8, 12, 16, and 32 Hz) on the speed perception of drivers were also analyzed. The test results reveal that the color and temporal frequency of sidewall marking have a significant impact on the driver's stimulus of subjectively equal speed and reaction time. The subjects have the highest speed overestimation and an easy speed judgment with the red–white combined sidewall marking. Within the temporal frequency range of 4.45–7.01 Hz, the subjects have a certain degree of speed overestimation (less than 20%), and the speed perception is sensitive to the temporal frequency changes. Copyright © 2016 John Wiley & Sons, Ltd.     

Integrated optimization of bus priority operations in connected vehicle environment

Most previous works associated with transit signal priority merely focus on the optimization of signal timings, ignoring both bus speed and dwell time at bus stops. This paper presents a novel approach to optimize the holding time at bus stops, signal timings, and bus speed to provide priority to buses at isolated intersections. The objective of the proposed model is to minimize the weighted average vehicle delays of the intersection, which includes both bus delay and impact on nearby intersection traffic, ensuring that buses clear these intersections without being stopped by a red light. A set of formulations are developed to explicitly capture the interaction between bus speed, bus holding time, and transit priority signal timings. Experimental analysis is used to show that the proposed model has minimal negative impacts on general traffic and outperforms the no priority, signal priority only, and signal priority with holding control strategies (no bus speed adjustment) in terms of reducing average bus delays and stops. A sensitivity analysis further demonstrates the potential of the proposed approach to be applied to bus priority control systems in real‐time under different traffic demands, bus stop locations, and maximum speed limits. Copyright © 2016 John Wiley & Sons, Ltd.     

基于 GT-Crank 仿真的柴油机气缸磨损时瞬时转速分析

利用 GT‐Crank 软件对柴油机曲轴瞬时转速进行仿真分析计算,研究了正常状态、单缸磨损、多个相邻缸磨损和多个非邻缸磨损状态下瞬时转速的变化规律,提取了状态特征参数,并分析了气缸磨损对其他缸的影响,为深入研究瞬时转速在柴油机状态检测诊断中的应用提供了理论依据。