Rheumatic complaints among Swedish engine drivers in relation to the dimensions of the driver's cab in the Rc engine

This paper compares the occurrence of rheumatic complaints among male engine drivers with their body measurements and with the dimensions of the cab in the Rc Swedish engine. 150 Swedish engine drivers were interviewed regarding symptoms from the musculoskeletal system. Relevant anthropometric measurements were obtained from each subject and compared with similar dimensions on a symptom free group of drivers matched for age. Data concerning the dimensions of the cab in the Rc engine were obtained from drawings and measurements of the cab. The results indicate that engine drivers with complaints in the lower back, neck and/or shoulders and/or the lower extremities were significantly shorter than controls in those anthropometric measurements related to correct sitting posture. Since the cab of the Rc engine is designed for tall engine drivers, the shorter driver appears to be at risk. Recommendations for cab designs suitable for all potential male and female drivers are appended.     

Assessment, re-design and evaluation of changes to the driver's cab in a suburban electric train

A new type of electric train, called the Tangara, began replacing older trains on the Sydney city and suburban network in 1990. Shortly afterwards, some of the train drivers began reporting pain in the arms while driving the new train. The Ergonomics Unit of Worksafe Australia was then engaged to identify and assess ergonomic problems in the driver's cab. This process included direct observation of drivers at work, distribution of a self-administered questionnaire to all drivers, and analysis of anthropometric problems using a computer-aided design package. The analysis of 193 completed questionnaires and the problems shown by the design study were used in developing an improved design. A mock-up of the modified cab was made and tried out by 134 drivers whose comments led to further changes. The modified design was applied to new production, and existing cabs were modified during major maintenance. By 1996, 96% of the driver's cabs were to the new design. An evaluation of the new design was undertaken using written questionnaires, which were completed by 227 drivers. The results were strongly in favour of the new design, showing the effectiveness of the ergonomic modifications.     

视频监测中的驾驶人面部特征点跟踪

由于具备多尺度多方向特性,Gabor小波常常被用于纹理分析及特征提取等方面的研究,并在驾驶人疲劳状态监测技术领域中获得较多的应用。首先介绍了Gabor小波的基本原理及使用方法,然后结合实例重点讨论驾驶人面部特征点跟踪的技术环节,包括Gabor小波的参数确定方法和待跟踪点特征向量提取方法,最后利用最大相识原则确定了3个备选结果。针对不同的图像条件,提出了Gabor小波在实际应用时需要注意的合理建议。实践证明,跟踪算法运算结果准确率较高,效果非常理想,能够为驾驶人疲劳状态分析打下良好的基础。     

虚拟驾驶员视觉感知模型研究

视觉是驾驶员获得驾驶信息的主要通道,虚拟驾驶员的视觉感知模型是驾驶行为建模与仿真的重要内容,直接影响驾驶行为仿真的逼真度。介绍了四种视觉感知建模方法,根据视觉感知系统的反馈性和选择性,建立了视觉感知模型。在模型中,将视觉感知分为感觉和知觉两个过程,并引入了注意力、记忆力、驾驶疲劳和驾驶经验等因素,对每个因素进行分析。通过对虚拟驾驶员视觉感知模型的仿真实验,验证了该模型的可靠性和有效性,为驾驶行为研究提供了基础。     

Analysis of sitting comfortability of driver's seat by contact shape

Abstract

In order to evaluate sitting comfort qualitatively, a flexible and very thin sensor was developed to measure the contact shape between a seated man and the seal surface. Each tape has twenty strain guages on it at regular intervals, and the fourteen tape sensors were arranged on the bottom and back surface of the experimental driver's seat. The contact shapes and postures in thirty two male drivers were measured with two types of seal cushion and sitting posture: free and recommended. Sensory evaluation was made for each experimental condition. The results of the interrelation between the characteristics of the surface deformation, the parameters of body build, sitting posture and feeling of comfort shows that the comfort of each morphological fitting does not correspond to one special and single parameter from those physical factors, but is represented by a function with many parameters related to the deformation, posture and body build. By using these relations, a sensory model for the prediction of the sitting comfort was constructed.     

An analytical investigation of isolation systems for cab ride

The dynamic performance capabilities of heavy duty trucks with suspended cabs are identified using a linearized model of heave-fore-aft-pitch dynamics. Cab acceleration levels and dynamic deflections are determined for vehicle performance on a randomly irregular road surface. The important trade-offs that limit the overall design are illustrated.     

一种红外图像条件下的驾驶人眼睛定位算法

利用机器视觉对驾驶人面部器官状态进行监测和分析处理是安全辅助驾驶领域内的研究热点之一。首先介绍了驾驶人驾驶行为监测及预警系统的原理和结构,然后讨论了系统中驾驶人眼睛定位的技术要点。通过人类眼睛虹膜对不同波长的红外光吸收能力的不同,利用特制的红外光源获取到驾驶人面部的两种红外反射图像,利用图像处理算法进行处理从而获得驾驶人的眼睛位置,从而为下一步的眼睛状态及信息提取打下了良好的基础。实践证明,算法的实时性高,效果非常理想。     

Lorry driver's time habits in work and their involvement in traffic accidents

Abstract

Using representative samples of drivers operating in freight transportation, the sociological features of lorry drivers, the process of formation of this group, and their work conditions are described. In many ways they are similar to other blue collar workers. The analysis of career evolution shows the existence of social processes of selection, whereby some people leave this sort of work, while others stay in it but try to improve their working conditions by migrating to firms offering better salaries and/or easier conditions.

As ‘normal’ durations and rhythms of work are known, it was possible to calculate the risk exposure to road accident involvement (according to the time at which the drivers are at the wheel and in relation to the amount of work already carried out) and to compare it, using a representative sample of the drivers involved, to the time features of the driver's activities prior to the accident. This demonstrated that the risk of involvement in an accident increases with the number of hours carried out, and according to the time at which the drivers are at the wheel (at the end of a normal working day and at night).

However, the relation between the duration of the work periods and the accident risk is not the same for different types of drivers. Younger drivers, and those in the Transportation Branch, are exposed to a higher global risk level, but apparently find various ‘resources’ to fight fatigue for the most dangerous threshold periods. Thus it is necessary to take account of physiological mechanisms on the one hand, and acquisition modes of ‘know-how’ which may compensate for fatigue, on the other.     

高速列车司机室三明治板的耐碰撞性能仿真

为验证高速列车司机室三明治板的被动安全设计是否符合要求,参照UIC 651标准运用MSC Dytran软件对某高速列车司机室三明治板的耐碰撞性能进行仿真,分析碰撞后三明治板的变形、应力、能量吸收以及弹头的速度曲线,表明司机室三明治板的耐碰撞结构能满足设计要求.     

Noise exposed of the operators of combine harvesters with and without a cab

A considerable number of the combine harvesters in Turkey are rather old and used without cabs resulting in unhealthy working conditions for their operators. Noise is one of the detrimental factors. This study deals with determining and comparing the noise exposed on the operators of the combines with and without a cab used for wheat harvesting in Turkey. The sound pressure levels (dB) at octave band center frequencies (31.5–8000 Hz) and the sound levels (dBA) at the ear level of the operators were measured on 37 different combine harvesters with four different makes and different years from 1976 to 2001. Fifteen of the combines were without a cab, another 15 had original cabs while remaining seven combines had cabs mounted on them after manufacturing.

The sound pressure levels were in a decreasing trend from the lower frequencies to higher frequencies. This trend was more noticeable for the combines with original cab and with the cab mounted after manufacturing compared to the ones without cab. The use of a cab was more effective in the insulation of the noise at the medium and higher frequencies, which have more bothersome effect compared to the lower frequencies. The sound pressure levels were 75–102 dB and 46–89 dB at low (31.5–500 Hz) and high (500–8000 Hz) frequencies for all combines, respectively. The sound pressure levels at the frequency of 4000 Hz at which the human ear is most sensitive were 6–17 dB lower for the combines with the cabs mounted after manufacturing and 9–28 dB lower for the ones with the original cabs compared to the combines without cab. The sound levels were 85–90, 81–83, and 76–81 dBA for the combines without cab, with cab mounted after manufacturing, and with original cab, respectively.

The study showed that the use of a cab was useful in the insulation of the noise, particularly at higher frequencies. In addition, it protects the operator from the factors having detrimental effects on the working efficiency such as high temperature and dusty environment. The authors strongly recommend mounting of a cab on to the combines currently being used without a cab in rental system in Turkey to provide healthy working conditions for their operators.     

Evaluation of lubricant condition and engine health based on soft computing methods

Neural Computing and Applications - Evaluating the condition of the lubricant plays an influential role in the maintenance engineering of mechanical systems. This study has several objectives and...     

Effect of button location on driver's visual behaviour and safety perception

Although buttons are a frequently used type of control in car interiors, little research has been undertaken on how the usage of buttons affects the visual behaviour of the driver. In this study, the aim was to analyse the effect of push button location and auditory feedback on drivers' visual time off road and safety perception when driving in a real traffic situation. The effect of six button locations (five on the centre stack, one near the gear stick) was tested. Drivers' visual behaviour was studied in real traffic on a motorway. An eye tracking system recorded the visual behaviour of eight drivers who, in 96 repeated trials each, were instructed to press a specific button. Data analysis focused on the drivers' visual time off road and safety perception in relation to the location of the button to be pressed. Auditory feedback did not show a significant effect on visual time off road. The time off road increased significantly as the angle increased between the normal line of sight and button location for the five buttons placed on the centre stack. Results for the button located close to the gear stick, with the highest eccentricity, produced a short time off road. This unexpected finding is discussed in terms of three potential explanations: 1) the role of perceptual discrimination; 2) risk perception; and 3) motor control.     

Effect of button location on driver's visual behaviour and safety perception

Although buttons are a frequently used type of control in car interiors, little research has been undertaken on how the usage of buttons affects the visual behaviour of the driver. In this study, the aim was to analyse the effect of push button location and auditory feedback on drivers' visual time off road and safety perception when driving in a real traffic situation. The effect of six button locations (five on the centre stack, one near the gear stick) was tested. Drivers' visual behaviour was studied in real traffic on a motorway. An eye tracking system recorded the visual behaviour of eight drivers who, in 96 repeated trials each, were instructed to press a specific button. Data analysis focused on the drivers' visual time off road and safety perception in relation to the location of the button to be pressed. Auditory feedback did not show a significant effect on visual time off road. The time off road increased significantly as the angle increased between the normal line of sight and button location for the five buttons placed on the centre stack. Results for the button located close to the gear stick, with the highest eccentricity, produced a short time off road. This unexpected finding is discussed in terms of three potential explanations: 1) the role of perceptual discrimination; 2) risk perception; and 3) motor control.     

Modeling of driver's collision avoidance maneuver based on controller switching model.

This paper presents a modeling strategy of human driving behavior based on the controller switching model focusing on the driver's collision avoidance maneuver. The driving data are collected by using the three-dimensional (3-D) driving simulator based on the CAVE Automatic Virtual Environment (CAVE), which provides stereoscopic immersive virtual environment. In our modeling, the control scenario of the human driver, that is, the mapping from the driver's sensory information to the operation of the driver such as acceleration, braking, and steering, is expressed by Piecewise Polynomial (PWP) model. Since the PWP model includes both continuous behaviors given by polynomials and discrete logical conditions, it can be regarded as a class of Hybrid Dynamical System (HDS). The identification problem for the PWP model is formulated as the Mixed Integer Linear Programming (MILP) by transforming the switching conditions into binary variables. From the obtained results, it is found that the driver appropriately switches the "control law" according to the sensory information. In addition, the driving characteristics of the beginner driver and the expert driver are compared and discussed. These results enable us to capture not only the physical meaning of the driving skill but the decision-making aspect (switching conditions) in the driver's collision avoidance maneuver as well.     

恶劣光照下驾驶人疲劳及注意力视觉监测算法

驾驶人驾驶行为监测及预警系统对于提高行车安全性及降低交通事故等问题具有重要作用,而利用机器视觉对驾驶人疲劳状态及注意力状态进行监测和分析是安全辅助驾驶领域内的研究热点之一。机器视觉受光照条件影响非常严重,甚至直接影响到图像处理算法的可靠性。在弱光和强光两种特殊照明条件下,介绍了驾驶人疲劳状态的检测思路,提出利用普尔钦斑点及投影曲线极点位置分割面部器官独立区域,最终获得眼睛的轮廓状态,利用PERCLOS判断驾驶人的疲劳状态。在驾驶人面部及面部器官定位的基础上,对驾驶人的头部旋转运动进行分析,提出了计算驾驶人头部旋转角度的计算方法,以驾驶人头部旋转角度为依据判断驾驶人的注意力是否分散。实践证明,在弱光和强光两种特殊照明条件之下,算法实时性好,准确率较高,效果非常理想,能够为驾驶人疲劳状态及注意力状态分析提供较为准确的依据。     

Measuring the effects of visual demand on lateral deviation: a comparison among driver's performance indicators

In this study we compare the efficacy of three driver's performance indicators based on lateral deviation in detecting significant on-road performance degradations while interacting with a secondary task: the High Frequency Component of steering wheel (HFC), and two indicators described in ISO/DIS 26022 (2007): the Normative and the Adapted Lane Change Test (LCT). Sixteen participants were asked to perform a simulated lane-change task while interacting, when required, with a visual search task with two levels of difficulty. According to predictions, results showed that the Adapted LCT indicator, taking into consideration individual practices in performing the LCT, succeeded in discriminating between single and dual task conditions. Furthermore, this indicator was also able to detect whether the driver was interacting with an easy or a difficult secondary task. Despite predictions, results did not confirm Normative LCT and HFC to be reliable indicators of performance degradation within the simulated LCT.