The influence of company identity on the perception of vehicle sounds

In order to determine how the interior of a car should sound, automotive manufacturers often rely on obtaining data from individual evaluations of vehicle sounds. Company identity could play a role in these appraisals, particularly when individuals are comparing cars from opposite ends of the performance spectrum. This research addressed the question: does company identity influence the evaluation of automotive sounds belonging to cars of a similar performance level and from the same market segment? Participants listened to car sounds from two competing manufacturers, together with control sounds. Before listening to each sound, participants were presented with the correct company identity for that sound, the incorrect identity or were given no information about the identity of the sound. The results showed that company identity did not influence appraisals of high performance cars belonging to different manufacturers. These results have positive implications for methodologies employed to capture the perceptions of individuals. STATEMENT OF RELEVANCE: A challenge in automotive design is to set appropriate targets for vehicle sounds, relying on understanding subjective reactions of individuals to such sounds. This paper assesses the role of company identity in influencing these subjective reactions and will guide sound evaluation studies, in which the manufacturer is often apparent.     

The impact of artificial vehicle sounds for pedestrians on driver stress

Electrically based vehicles have produced some concern over their lack of sound, but the impact of artificial sounds now being implemented have not been examined in respect to their effects upon the driver. The impact of two different implementations of vehicle sound on driver stress in electric vehicles was examined. A Nissan HEV running in electric vehicle mode was driven by participants in an area of congestion using three sound implementations: (1) no artificial sounds, (2) manually engaged sounds and (3) automatically engaged sounds. Physiological and self-report questionnaire measures were collected to determine stress and acceptance of the automated sound protocol. Driver stress was significantly higher in the manually activated warning condition, compared to both no artificial sounds and automatically engaged sounds. Implications for automation usage and measurement methods are discussed and future research directions suggested.

Practitioner Summary: The advent of hybrid- and all-electric vehicles has created a need for artificial warning signals for pedestrian safety that place task demands on drivers. We investigated drivers’ stress differences in response to varying conditions of warning signals for pedestrians. Driver stress was lower when noises were automated.     

A fuzzy multi-objective covering-based vehicle location model for emergency services

Timeliness is one of the most important objectives that reflect the quality of emergency services such as ambulance and firefighting systems. To provide timeliness, system administrators may increase the number of service vehicles available. Unfortunately, increasing the number of vehicles is generally impossible due to capital constraints. In such a case, the efficient deployment of emergency service vehicles becomes a crucial issue. In this paper, a multi-objective covering-based emergency vehicle location model is proposed. The objectives considered in the model are maximization of the population covered by one vehicle, maximization of the population with backup coverage and increasing the service level by minimizing the total travel distance from locations at a distance bigger than a prespecified distance standard for all zones. Model applications with different solution approaches such as lexicographic linear programming and fuzzy goal programming (FGP) are provided through numerical illustrations to demonstrate the applicability of the model. Numerical results indicate that the model generates satisfactory solutions at an acceptable achievement level of desired goals.     

The discomfort produced by noise and whole-body vertical vibration presented separately and in combination

This study investigated the prediction of the discomfort caused by simultaneous noise and vibration from the discomfort caused by noise and the discomfort caused by vibration when they are presented separately. A total of 24 subjects used absolute magnitude estimation to report their discomfort caused by seven levels of noise (70–88 dBA SEL), 7 magnitudes of vibration (0.146–2.318 ms^? 1.75) and all 49 possible combinations of these noise and vibration stimuli. Vibration did not significantly influence judgements of noise discomfort, but noise reduced vibration discomfort by an amount that increased with increasing noise level, consistent with a ‘masking effect’ of noise on judgements of vibration discomfort. A multiple linear regression model or a root-sums-of-squares model predicted the discomfort caused by combined noise and vibration, but the root-sums-of-squares model is more convenient and provided a more accurate prediction of the discomfort produced by combined noise and vibration.     

基于混合整数规划的智能车横纵向一体化滚动优化决策

本文针对智能车辆的行为决策问题, 设计了基于混合整数规划的智能车横纵向一体化滚动优化决策方法. 该方法首先将纵向车速表示为非整数, 将期望车道表示为整数控制量, 建立了混合整数智能车决策简化模型; 然后, 设计了横纵向一体化滚动优化决策方法, 决策出纵向车速和换道动作, 根据系统输出与非线性约束的时域关系证明 了优化问题的递归可行性并通过遗传算法求解非线性混合整数规划优化问题. 基于车辆动力学仿真软件veDYNA 和Simulink进行了联合仿真, 并在红旗E-HS3智能车上开展了实车试验, 结果表明, 本文提出的基于混合整数规划的 智能车横纵向一体化决策方法能够实现超车、避障、跟车、停车和弯道工况下的行为决策.     

汽车姿态感知与状态预测平台的研究

设计了集成加速度计、角速度计和磁力计的MEMS汽车姿态感知平台,并通过单片机对感知信息进行数据滤波、数据融合以及姿态解算等步骤,获得汽车的实时姿态信息。在PC机上建立了自回归模型,用于对汽车运动姿态的实时感知和短期预测。     

智能车载感知与侧翻预警系统的设计

为了防止汽车在行驶过程中发生侧翻,使汽车始终处在安全工况下行驶,减少交通事故,设计了一种基于ARM9的智能车载感知和侧翻预警系统,对汽车在途行驶时的侧倾角和侧倾角速度进行监测,并采用多阶递推模型对汽车侧倾姿态进行预测,当预测到侧倾达到极限工况时发出报警信息,提醒驾驶人员注意并采取相应减少侧向加速度的措施,从而达到预防汽车侧翻事故的发生,并基于VB2005,Matlab和NIMeasurement Studio开发了车载感知与侧翻预警系统软件,进行了系统仿真。实车道路试验与系统仿真实验进行了比较,结果表明:车载感知和预警系统能够及时准确预测汽车侧翻,提高汽车主动安全。     

车载感知与智能终端的硬件设计

以S3C2440为核心,以WinCE操作系统作为平台,设计了基于CAN总线的车载感知硬件电路,运用微惯性测量单元实现对汽车自身运动状态的在线测量,并实现信息在智能终端的显示。融合当前流行的智能车载终端模块,实现GPS车载导航、GPRS无线通信、无线上网和智能报警等功能。     

利用人眼感知视觉模型的车型动态定位

通过对实时汽车图像的大量研究，提出基于人眼感知视觉模型的自适应汽车车体定位算法。在HSI彩色图像空间，根据人眼分辨率的视觉感知模型分别在色度、亮度和饱和度空间进行自适应的边缘检测，将3个空间得到的图像边缘合并以得到整个车体在实际影像序列中的边缘，最后利用投影知识原理，分别利用边缘的垂直投影图和水平投影图来定位车体的左右边界和上下边界。实验结果表明，该算法具有较快的速度和较好的准确性，能满足实时的车型识别系统的要求。     

The analysis of vehicle sounds for recognition

The problem of classifying vehicles on the basis of the acoustic waveform obtained from them has been approached by calculating various central moments of the short term power spectrum of a sample of the signal. It has been found that classification can be performed using two moment measurements, giving good results with vehicles operating under steady running conditions. With a burst of acceleration included in the sample, however, discrimination becomes much more difficult. In the moment space under consideration, it became evident that the movement of sample points with changes of engine speed was itself characteristic of the vehicle class, and this consideration amongst others suggested that the engine speed (or, in practice, the firing rate of the engine) was an important parameter that needs to be determined automatically.

The first attempt at finding the fundamental frequency of the waveform was based on autocorrelation, but this gave very unsatisfactory results. The technique of “cepstrum” analysis, however, is shown to give a reliable indication of the firing rate even when the engine sound is deeply embedded in noise. This is in contrast to results obtained by some earlier workers using this analysis in speech studies.     

特种车辆驾驶人机界面匹配评价系统的研究

特种车辆驾驶人机界面匹配问题是复杂而重要的问题.根据人机工程学原理和研究方法,对特种车辆驾驶人机界面匹配问题进行了系统研究,提出了一套定量化的驾驶人机界面综合评价计算模型.以此为依据研发了特种车辆驾驶人机界面的计算机评价计算系统,介绍了系统的设计思想及数据处理方法.运用该系统对某军用车辆进行了评价,得出了与实际情况非常吻合的评价结果.     

两级车辆路径问题下的应急物资配送策略与绩效

研究应急物资配送中的两级车辆路径决策策略与应急物资配送绩效问题。首先以最后完成任务的最小时间为目标,建立了两级车辆路径模型;然后针对主仓库恢复配送时间不确定性问题,提出了4种应对策略：独立策略、乐观协同策略、悲观协同策略和折中协同策略,设计了多起点迭代局部搜索算法和仿真程序;最后通过数值算例比较了4种策略对应急物资配送绩效的影响,比较结果表明,折衷协同策略的表现效果最好。     

基于无线传感器网络的车辆检测识别算法研究

针对无线传感器网络(WSNs)的特点,利用车辆发出的声音信号,提出并研究了一种改进的信号检测算法,能够有效地从被噪声严重污染的声音信号中提取出车辆信号。使用小波包变换提取16维信号特征,支持向量机进行目标分类,得到单节点识别结果。提出了基于能量的全局决策融合算法,对多个节点做出的决策进行融合,得到网络的最终识别结果。为了评估算法,使用了来自DARPA SensIT实验中的真实数据,其中包含了履带车和重型卡车的大量声音信号。实验结果表明:该算法用于WSNs中的车辆识别方面是有效的。     

On determining optimal fleet size and vehicle transfer policy for a car rental company

This paper considers how to determine the optimal fleet size and vehicle transfer policy for a rental-car company that serves two cities. In each city, there are single-trip and round-trip customers, where the former is given a higher priority. Because of the single-trip traffic, the number of cars at these two cities may become unbalanced. Hence, the central planner in each day needs to decide whether to transfer any cars from one city to the other. We develop a two-stage dynamic programming model, in which we determine the vehicle transfer policy in the second stage and the optimal fleet size in the first stage. Although the objective function could be neither concave nor quasi-concave due to lost sales, we can find the optimal fleet size and vehicle transfer policy by solving a series of linear programming problems. We propose a heuristic solution, which is based on a special case analysis, for the fleet size problem. A numerical study reveals that our heuristic solution for the fleet size performs well. However, if the corresponding vehicle transfer policy is not appropriate, the overall performance can drastically deteriorate even with the optimal fleet size. Several extensions of our basic model are also analyzed.     

Noise effect on comfort in open-space offices: development of an assessment questionnaire

It is currently accepted that noise is one of the most important annoyance factors in open-space offices. However, noise levels measured in open spaces of the tertiary sector rarely exceed 65 dB(A). It, therefore, appears necessary to develop a tool that can be used to assess the noise environment of these offices and identify the parameters to be taken into consideration when assessing the noise annoyance. This article presents a questionnaire to be filled by people working in such environment, and a case study in different open plan offices. The majority of the 237 respondents consider that the ambient noise level in their environment is high and that intelligible conversations between their colleagues represent the main source of noise annoyance. This annoyance was significantly correlated with their evaluation of sound intensity, which could not be represented by A-weighted level measurements.     

基于前景理论的交互式群组风险决策方法

为了克服现有方法因立论假设过于理想而存在决策结果的科学性和满意性较差以及决策过程效率低下等缺陷,基于前景理论构建了能够吸纳多种模糊信息且能从中识别有效前景的优选模型及判别定理,并针对结果价值的交互学习提出了具有收敛性的交互式决策方法。数值模拟分析表明,所提出的方法既能反映群组成员风险偏好,保证决策结果具有科学性、满意性,又能平衡信息完善程度与其获取成本之间的矛盾关系,保证决策过程具有有效性和可行性。     

Effect of noise on comfort in open-plan offices: application of an assessment questionnaire

Abstract

Open-plan offices account for 60% of French office workspaces. The noise levels recorded in this type of environment are much lower than those encountered in industrial workplaces. Nevertheless, surveys show that noise is considered by employees as the main source of discomfort. A first questionnaire dedicated to noise discomfort was produced in 2013 and tested on a panel made up of 217 people working in 7 French companies. Today, it also makes it possible to address the issues of fatigue related to ambient sound, but above all, the survey aims to study the differences in how ambient noise is perceived depending on the type of open-plan office. On the basis of that new version, a second survey has been conducted in 23 open-plan offices, making it possible to collect the responses from 617 employees. Most of the results of the first survey have been confirmed, with an increase in the significance of the statistical analyses. Moreover, French Standard NF S 31-199, which is currently being drafted, establishes a typology of open-plan office spaces according to the types of work done in them. Based on this typology, it appears that when dealing with the impact on noise on workers, a distinction has to be made between the types of open plan offices.

Practitioner Summary: Surveys conducted in open-plan offices show that noise is considered by employees as the main source of discomfort even if the noise recorded in this type of environment is not hazardous. This work presents the result of a large survey dedicated to noise discomfort conducted in 23 open-plan offices.     

基于车辆任务可靠性的协同车辆路径问题

研究一类属于不同公司的配送中心共享车队、仓储等资源为客户协同配送货物的协同车辆路径问题, 将之视为“部分客户被一车辆访问”的集合划分问题。考虑车辆容量、车辆行驶最大里程、车辆配送任务的可靠性概率、时间窗等约束条件, 建立以车辆配送总费用最小为目标的混合整数规划模型, 并设计了求解该问题的遗传算法求解该问题。最后, 通过一个算例验证了模型的正确性和合理性。     

用Bark频谱投影识别低信噪比动物声音

复杂环境声影响低信噪比动物声音的自动识别。为解决这一问题,本文提出一种不同声场景下低信噪比动物声音识别的方法。该方法把声音信号进行Bark尺度的小波包分解,再使用分解系数生成重构信号的频谱,并对频谱进行投影生成Bark频谱投影特征,通过随机森林分类器实现低信噪比动物声音的识别。该文分别在流水声环境、公路环境、风声环境和嘈杂说话声环境下,以不同的信噪比,对40种动物声音进行识别实验。结果表明,结合短时谱估计法、Bark频谱投影特征和随机森林的方法对不同信噪比的各种环境声音中动物声音的平均识别率可以达到80.5%,且在-10 dB的情况下依然保持平均60%以上的识别率。