Numerical Prediction of Ride Comfort of Tracked Vehicle Equipped with Novel Flexible Road Wheels

Enhancing ride comfort has always constituted a crucial focus in the design and research of modern tracked vehicles,heavily reliant on the driving system's performance.While the road wheel is a key component of the driving system,traditional road wheels predominantly adopt a solid structure,exhibiting subpar adhesion performance and damping effects,thereby falling short of meeting the demands for high-speed,stable,and long-distance driving in tracked vehicles.Addressing this issue,this paper proposes a novel type of flexible road wheel(FRW)characterized by a catenary construction.The study investigates the ride comfort of tracked vehicles equipped with flexible road wheels by integrating finite element and vehicle dynamic.First,three-dimensional(3D)finite element(FE)models of both flexible and rigid road wheels are established,considering material and contact nonlinearities.These models are validated through a wheel radial loading test.Based on the validated FE model,the paper uncovers the relationship between load and radial deformation of the road wheel,forming the basis for a nonlinear mathematical model.Subsequently,a half-car model of a tracked vehicle with seven degrees of freedom is established using Newton's second law.A random road model,considering the track effect and employing white noise,is constructed.The study concludes by examining the ride comfort of tracked vehicles equipped with flexible and rigid road wheels under various speeds and road grades.The results demonstrate that,in comparison to the rigid road wheel(RRW),the flexible road wheel enhances the ride comfort of tracked vehicles on randomly uneven roads.This research provides a theoretical foundation for the implementation of flexible road wheels in tracked vehicles.

Optimisation of Thermal Comfort of Building in a Hot and Dry Tropical Climate: A Comparative Approach between Compressed Earth/Concrete Block Envelopes

Compressed earth blocks (CEB) are an alternative to cement blocks in the construction of wall masonry. However, the optimal architectural construction methods for adequate thermal comfort for occupants in hot and arid environments are not mastered. This article evaluates the influence of architectural and constructive modes of buildings made of CEB walls and concrete block walls, to optimize and compare their thermal comfort in the hot and dry tropical climate of Ouagadougou, Burkina Faso. Two identical pilot buildings whose envelopes are made of CEB and concrete blocks were monitored for this study. The thermal models of the pilot buildings were implemented in the SketchUp software using an extension of EnergyPlus. The models were empirically validated after calibration against measured thermal data from the buildings. The models were used to do a parametric analysis for optimization of the thermal performances by simulating plaster coatings on the exterior of walls, airtight openings and natural ventilation depending on external weather conditions. The results show that the CEB building displays 7016 hours of discomfort, equivalent to 80.1% of the time, and the concrete building displays 6948 hours of discomfort, equivalent to 79.3% of the time. The optimization by modifications reduced the discomfort to 2918 and 3125 hours respectively;i.e. equivalent to only 33.3% for the CEB building and 35.7% for the concrete building. More study should evaluate thermal optimizations in buildings in real time of usage such as residential buildings commonly used by the local middle class. The use of CEB as a construction material and passive means of improving thermal comfort is a suitable ecological and economical option to replace cementitious material.

Experimental Study on the Ride Comfort of a Crawler Power Chassis Scale Model Based on the Similitude Theory

The ride comfort experimental assessment of crawler off-road vehicle is relatively overlooked, and is expensive and difficult to execute with higher and higher ride comfort performance requirements. To trade off between precise and cost, an experimental method based on the similitude theory is proposed. Under the guidance of the similitude theory, a 1：5 crawler power chassis scale model equipped with a kind of variable stiffness suspension system is used. The power spectrum density（PSD）, the root mean square（RMS） of weighed acceleration, peak factor, average absorbed power（AAP） and vibration dose value（VDV） are selected as ride comfort evaluation indexes, and tests results are transformed via similarity indexes to predict the performance of full-scale power chassis. PSD shows that the low-order natural frequency of the vertical natural frequency（z axis） is 1.1 Hz, and the RMS, AAP and VDV values indicate the ride comfort performance of this kind of power chassis is between the ＂A little uncomfortable＂ and ＂Rather uncomfortable＂. From the results, low-order vertical natural frequency, obtained by PSD, validates that the similarity relationship between two models is satisfied, and 1：5 scale model used in experiment meets the similarity relationship with the full-scale model; consequently, the ride comfort prophase evaluation with the 1：5 scale model is feasible. The attempt of applying the similitude theory to crawler vehicle ride comfort test study decreases the cost and improves the test feasibility with sufficient test precise.

Field study of seasonal thermal comfort and adaptive behavior for occupants in residential buildings of Xi’an,China

The study aims to investigate the thermal comfort requirements in residential buildings and to establish an adaptive thermal comfort model in the cold zone of China.A year-long field study was conducted in residential buildings in Xi’an,China.A total of 2069 valid questionnaires,along with indoor environmental parameters were obtained.The results indicated occupants’thermal comfort requirements varied with seasons.The neutral temperatures were 17.9,26.1(highest),25.2,and 17.4℃(lowest),and preferred temperatures were 23.2,25.6(highest),24.8,and 22.4℃(lowest),respectively for spring,summer,autumn,and winter.The neutral temperature and preferred temperature in autumn are close to the neutral temperature in summer,while the neutral temperature and preferred temperature in spring are close to that in winter.Besides,the 80%and 90%acceptable temperature ranges,adaptive thermal comfort models,and thermal comfort zones for each season were established.Human’s adaptability is related to his/her thermal experience of the current season and the previous season.Therefore,compared with the traditional year-round adaptive thermal comfort model,seasonal models can better reflect seasonal variations of human adaptation.This study provides fundamental knowledge of the thermal comfort demand for people in this region.

Research on the Winter Thermal Comfort of Library's Atrium Reading Space in Harbin Universities

As a transition space,atrium not only organizes traffic,makes the flow line flexible,but also modulates the indoor micro-climate. Because of its good sense of space and lighting performance,designers generally set reading space around the atrium. But nowadays,people are more concerned with the external form of the architecture,rather than the thermal comfort conditions of the atrium reading space. This article chooses the universities' library atrium space of Harbin in typical city in cold regions as the carrier of research,testes the thermal environment of atrium reading space, analyzes the user 's subjective feelings of the thermal environment and establishes climate adaptation model applied to library buildings. This paper aims to study on Winter thermal comfort of universities' library atrium reading space in cold area. Bases on thermal comfort adaptive model,it establishes a reasonable heating methods and design temperature index of indoor thermal environment. Optimum comfort is obtained while achieving building energy efficiency and providing viewers a comfortable reading space.

Effect of the off-road terrains on the ride comfort of construction vehicles

In order to evaluate the impact of off-road terrains on the ride comfort of construction vehicles,a nonlinear dynamic model of the construction vehicles interacting with the terrain deformations is established based on Matlab/Simulink software.The weighted root mean square(RMS)acceleration responses and the power spectral density(PSD)acceleration responses of the driver s seat heave,the pitch and roll angle of the cab in the low-frequency region are chosen as objective functions under different operation conditions of the vehicle.The results show that the impact of off-road terrains on the driver s ride comfort and health is clear under various conditions of deformable terrains and range of vehicle velocities.In particular,the driver s ride comfort is greatly affected by a soil terrain while the comfortable shake of the driver is strongly affected by a sand terrain.In addition,when the vehicle travels on a poor soil terrain in the frequency range below 4 Hz,more resonance peaks of acceleration PSD responses occurred than that on a rigid road of ISO 2631-1 level C.Thus,the driver s health is significantly affected by the deformable terrain in a low-frequency range.

Prediction Research on Ride Comfort of Special Full Trailer used by Precision Equipment

In order to evaluate a full trailer’s vibration performance,lumped mass model of seven degrees of freedom is set up to predict the ride comfort of whole vehicle.The acceleration history and the transfer function of each measuring point can be got from simulation.The analysis results show that the maximum acceleration RMS value of the vehicle mass center is about 0.3g,which satisfies the requirements of attenuating vibration of precision equipment being transported on particular roads and speeds.So the research provides valuable reference for the optimum selection of the suspension system’s parameters.

Effects of personal heating on thermal comfort:A review

Personal conditioning system(PCS)is receiving considerable attention due to its energy-saving potential and the ability to satisfy individual comfort requirements.As a part of PCS,personal heating systems can maintain human thermal comfort in cold environments,which leads to their potential role of important heating mode in cold winter,especially in the Hot Summer and Cold Winter regions of China.In order to better promote the development and application of personal heating systems,this paper reviews the published studies.Personal heating systems can be divided into four types based on the mode of heat transfer:conductive,convective,radiative and combinative type.Characteristics of each category and respective devices are introduced.Furthermore,identifying the effects of personal heating on thermal comfort and the models for predicting or evaluating thermal comfort during local heating.This paper would provide users with a guideline for choosing suitable heating equipment during winter.

Research on Ride Comfort Model of Wheel Motor Driving Vehicle Based on Matlab/Simulink

Simulink is a visual simulation tool in MATLAB;?through Simulink software,?to establish a model can reduce the amount of programming workload,?and?improve the efficiency of the establishment of automotive models.?The ride comfort of the vehicle is a measure of the most basic indicators of a car performance.?By establishing a ride comfort model in Matlab/Simulink, the wheel motor electric vehicle mainly affects the smoothness of the car mainly in the following aspects:?pavement, tire, suspension, motor and so on.?Through the establishment of the above model,?we?can effectively study the wheel motor drive electric vehicle ride comfort research.

Optimisation of Climate Robust Buildings under Summer Conditions with ＂Primero-Comfort＂ Simulation Software Including Detailed User Behaviour and Comfort Expectance

In this paper the possibilities for avoiding active air conditioning by all means of the room itself （window size, glazing, shading system, natural ventilation, and furniture）, artificial light and control strategy of these systems are investigated. A very important component of the system is the user with his ability to adapt to changing conditions in his surrounding and with his possibilities to manipulate the window, the shading system, the light switch etc. All these aspects interact together. It is necessary to optimize them simultaneously. But real planning often separates them into single sections. Simulation tools also handle normally only one or a few aspects, we know for example the thermal simulation or the daylight simulation. Primero-Comfort （2009） is a simulation tool based on energy＋, what is able to consider thermal simulation as well as daylight simulation as well as user behaviour in regard to the probability of window openings. The resulting thermal comfort is rated by an adaptive comfort model, the Dutch ISSO 74 （2004）. This allows designing office rooms more realistic. And it shows that an optimized solution has to include the interactions of aU mentioned aspects. Investigations with Primero-Comfort for a moderate European climate （Hamburg） show that a very good comfort can be reached only by passive means of building design also for hot summer weather just like the summer in the year 2003. The keys for such hot-summer-robust-buildings are night ventilation with height difference, heat protection glazing and good shading system, reduced internal heat gains for artificial light by accepting a threshold of 300 lx of daylight as comfortable and a reduced window size oriented on daylighting and the view out of the window.

Human Comfort Evaluation of a Steel-Concrete Composite Building Subjected to Aerobics

The current steel-concrete composite floors design might be susceptible to the resonance phenomenon, causing undesirable vibrations in the frequency range that is the most noticeable to humans, i.e., 4 Hz to 8 Hz. This way, the main objective of this work is to investigate the dynamic structural behaviour of a steel-concrete composite multi-storey building when subjected to human rhythmic activities （aerobics）. The studied structural model represents a typical interior floor bay of a commercial building used for gym and is composed by three floor levels spanning 20 m by 20 m, with a total area of 3×400 m2. An extensive parametric study was developed aiming to obtain the peak accelerations, RMS （root mean square） accelerations and VDV （vibration dose value） values, based on two different mathematical formulations. The human comfort of the building was analysed and the vibration transmissibility related to the steel columns was verified. Based on the found results, the investigated structural model presented high vibration levels that compromise the human comfort.

The Effects of Building Form on Microclimate and Outdoor Thermal Comfort in a Tropical City

The urban microclimate has direct implications with regards to thermal comfort indoors as well as outdoors. In the tropics, the outdoor thermal comfort conditions during daytime are often far above acceptable comfort standards due to intense solar radiation and high solar elevations. This study aims to know effects of simple and fundamental building forms on microclimate and outdoor thermal comfort in a high dense tropical city, focusing on Dhaka, Bangladesh as a study city. Investigations are carried out on existing area and model areas with modified building forms （in respect of height and shape） on the microclimate as well as on outdoor thermal comfort during daytime in summer. This study has demonstrated that the model using less ground coverage and higher buildings can offer a better thermal climate than the models using maximum ground coverage in a high-density tropical city.

Comparative Study of the Thermal Comfort of Four Materials Type Used in the Construction of a Building

This research work consisted in making a comparative study of the thermal comfort of four materials types used in the construction of a building.A simulation of the building with the various materials on the KoZiBu software in reference and optimized situation was carried out.A study on the sensitive and air-conditioning loads as well as the curves of temperatures on a building of type F2 in situation of reference and in optimized situation was made on the one hand and the other hand a study on the same building without air-conditioning in reference and optimized situation.Finally,the analysis of the results favorizes the choice of the material having the best thermal comfort.The conclusions of these works show that the material that can give the best comfort and the most economics in terms of energy is the adobe which offers temperatures(301.40K or 28.40°C)and a good indoor thermal environment compared to BLT(blocks of cut laterite),BTC(blocks of compressed earth)and cinder block.Dwellings built with earthen materials offer a better indoor thermal environment than those built with modern construction materials,which are used more and more in the construction of houses in Burkina Faso.

Analysis of Thermal Behavior of Materials in the Building Envelope Using Building Information Modeling (BIM)—A Case Study Approach

Building envelope is a fence that controls heat exchange between interior and exterior and plays an essential role in providing thermal comfort conditions of residents. In recent years, due to the necessity of conserving energy and also preventing increased environmental pollution, the importance of sustainable construction has been doubled. Checking the problems of thermal behavior of the building envelope materials, and what influences in the heating and cooling loads exerted and energy consumption of buildings, are the questions that this research seeks to answer. In this regard, building information modelling analysis (BIM) has worthy contribution in the completion process of sustainable design;thus using software Design Builder, it is paid attention to simulation of the thermal behavior of two types of defined materials for the building envelope that was designed as a Research Institute of Renewable Energy of Yazd University. For Type 1 materials, two layers of brick have been selected, and for Type 2 a thermal insulation layer also added it. Results of the analysis showed that the use of materials Type 2 in the cooling load %4.8 and in the thermal load %62.5 reduction can be achieved which means reducing the load on active system and thus reducing the initial cost of building. Also reduction in annual energy consumption by almost %2.4 for cooling and %62.9 for heating buildings have been achieved, which makes saving non-renewable energy consumption, and consequently reducing environmental pollution as well as reducing current costs will be established.

共享汽车驾驶员适宜H点和座椅参数实验研究

共享汽车具有车型统一、用户多变且使用频率高的特点,为提升共享汽车使用效率和驾乘体验,研发一种能根据驾驶员特征自动调节舒适坐姿的智能座椅意义重大。本文针对用户座椅调节存在的主观任意性导致的座椅舒适性问题,结合共享汽车智能座椅项目,以座椅H点前后位置、H点高低位置、坐垫角和靠背角4个变量为研究因子进行台架实验,分别研究5th、50th和95th百分位驾驶员的座椅舒适性受座椅参数的影响规律。首先,每个研究因子在参考车型范围内均匀选取3个实验水平,采用正交实验表对实验次数进行简化,确定正交实验须进行的组数并进行正交台架实验。实验人员对每组的座椅舒适性进行主观评价,同时通过压力测量仪和数显角度尺测量实验人员的体压分布信息和关节角度信息;其次,通过聚类分析确定了本文采用的以关节角度为客观参数的主客观舒适性评价体系,通过正交实验分析,得出了不同座椅参数对座椅舒适性的影响存在差异的结论,且随着驾驶员百分位的变化,对座椅舒适性造成影响的参数也在发生变化;最后,对正交实验所得数据进行修正拟合,构建了座椅适宜H点位置预测模型和靠背角度预测模型。

考虑驾驶风格和舒适性的电动汽车制动能量回收策略

现有的制动能量回收策略未充分考虑驾驶风格对前、后轴制动力矩分配的影响,降低了能量回收率,增加了制动减速度。为此,提出了一种考虑驾驶风格和制动舒适性的再生能量回收策略,对不同驾驶风格的驾驶员采用不同的权重系数去权衡制动能量回收效率与制动舒适性。设计模糊规则控制器对驾驶员舒适性权重进行分配,建立包含舒适性和制动能量回收效率的多目标优化模型。最后结合考虑电池、电机特性和紧急工况等影响因素确定制动力矩分配策略。仿真结果表明,与其他控制策略相比,所提出的控制策略使驾驶员处于舒适与轻微不适的占比分别增加3.4%和1.58%,并消除严重不适,电池SOC值损失0.3183%。

移乘背抱护理机器人舒适性生物力学模型分析

为探索移乘背抱护理机器人人机交互力学特性与被护理人舒适性感受的潜在关联,研究显性的人机接触力相对于人体生物力学特性的映射关系,揭示影响被护理人舒适性的主要作用肌群,提出了舒适性测试试验与AnyBody背抱运动人体生物力学模型相结合的方法.从被护理人的肌肉激活程度入手,对移乘背抱护理机器人背抱运动舒适性特征进行了分析.首先,介绍了移乘背抱护理机器人典型结构工作原理并进行了运动学分析,在此基础上搭建了舒适性测试试验系统,基于主观舒适性评分规划了服务于试验的基础运动轨迹,并通过试验得到了人机主要接触部位力学信息.然后,以试验数据为边界条件构建了基于AnyBody的背抱运动人体生物力学模型,依托逆动力学仿真分析得到了肌肉激活程度,并对比舒适性测试肌肉激活程度验证了仿真模型的有效性.最后,结合人机主要接触部位受力、肌肉激活程度及主观舒适性评分综合分析了移乘背抱护理机器人背抱运动舒适性特征,明确了影响被护理人舒适性的主要作用肌群.结果表明:影响被护理人舒适性的主要作用肌群有7个,且被护理人胸部压力与腋下压力值大小分别与影响其躯干和上肢舒适性的肌肉激活程度呈正相关.可通过建立胸部压力与腋下压力值相关的加权函数有效描述不同被护理人整体舒适性特征,为移乘背抱护理机器人舒适性运动控制提供了理论依据.

基于驾驶模拟的隧道照明对行车安全及舒适度评价影响研究

随着交通运输基础设施建设发展模式由追求速度规模向更加注重质量效益转变,精细化、因地制宜地设定隧道照明环境需求日益增多.隧道照明系统设计应以保证驾驶员行车的安全性与舒适度为前提,因此需要对隧道照明如何影响驾驶员隧道行车的安全性与舒适度进行量化评估.基于隧道照明理论和驾驶员行车基础研究,选取影响驾驶员安全性与舒适度的8项指标,建立驾驶员安全性与舒适度评价体系,并通过隧道驾驶仿真环境与硬件设施实现室内仿真研究:基于UC-win/Road软件建立隧道虚拟仿真模型,通过驾驶模拟器和生理仪器获取8项指标对应的数据,对数据进行处理后通过熵权法确定指标权重,评估不同照明亮度与色温环境下的隧道安全性与舒适度.以驾驶员的行车安全及舒适评价值最优为目的,得出隧道内亮度和色温的最佳设定值.实验结果验证了驾驶员行车安全与舒适度评价体系的有效性,提出了改进的照明方案,为隧道运营方提供参考.

萧氏舒适护理模式联合加速康复外科理论在肝癌手术患者中的应用价值研究

目的:探讨萧氏舒适护理模式联合加速康复外科理论在肝癌手术患者中的应用价值。方法:选取2021年1月—2022年12月在桂林医学院附属医院行肝癌手术的90例患者按照就诊顺序机械分为(就诊先后顺序123循环分组)舒适护理组、加速康复组、联合组,分别给予萧氏舒适护理、加速康复外科理论指导下的护理模式、萧氏舒适护理模式联合加速康复外科理论指导下的护理模式,比较三组术后恢复指标、术后并发症发生情况、入院时及出院前焦虑自评量表(SAS)评分、抑郁自评量表(SDS)评分、生存质量、护理服务满意度。结果:三组术后首次排气时间、排便时间、术后住院时间、住院费用对比差异均有统计学意义(P<0.05),联合组首次排气时间、排便时间均早于舒适护理组、加速康复组,术后住院时间较舒适护理组、加速康复组显著短,住院费用较舒适护理组、加速康复组显著少,差异均有统计学意义(P<0.05)。术后联合组并发症发生率为6.67%,较舒适护理组(53.33%)、加速康复组(50.00%)显著低,差异均有统计学意义(P<0.05)。入院时三组SAS、SDS评分差异均无统计学意义(P>0.05),出院前联合组SAS、SDS评分较舒适护理组、加速康复组均显著低,差异均有统计学意义(P<0.05)。入院时三组卡氏功能状态(KPS)评分差异无统计学意义(P>0.05),出院前三组KPS评分均显著提高,且出院前联合组KPS评分较舒适护理组、加速康复组均显著高,差异均有统计学意义(P<0.05)。术后联合组对护理服务满意率为93.33%,较舒适护理组(63.33%)、加速康复组(56.67%)均显著高,差异均有统计学意义(P<0.05)。结论:萧氏舒适护理模式联合加速康复外科理论应用于肝癌患者可改善胃肠功能,缩短住院时间,减轻负性情绪,降低并发症,提高生活质量及护理服务满意度。

Plan-Do-Check-Act模式联合舒适化护理对肝硬化并腹水患者的影响

目的:探讨Plan-Do-Check-Act(PDCA)模式联合舒适化护理对肝硬化并腹水患者心理状态、并发症及生存质量的影响.方法:选取2021年8月至2023年3月本院收治的104例肝硬化并腹水患者作为研究对象.根据护理方案,将其分为实验组(n=54,给予PDCA模式联合舒适化护理)和对照组(n=50,给予舒适化护理).比较两组患者汉密尔顿焦虑量表(HAMA)、汉密尔顿抑郁量表(HAMD)、世界卫生组织生存质量测定量表简表(WHOQOL-Bref)评分及并发症发生率.结果:干预后,实验组患者HAMA、HAMD评分低于对照组,WHOQOL-Bref量表各方面评分高于对照组,差异均有统计学意义(P<0.05);实验组并发症总发生率低于对照组,差异具有统计学意义(P<0.05).结论:PDCA模式联合舒适化护理干预可改善肝硬化并腹水患者心理状态,降低并发症发生率,提高生存质量.