Computer simulation of all terrain vehicle vibration performance

In order to assess the vibration performance of all terrain vehicles, a half vehicle model with 10 degrees of freedom was built. The model was solved using the time domain method. Road surface irregularity excites the model and was generated by a trigonometric function. Based on this model, the beaming of the frame was analyzed. The results show that the first beaming and second beaming influence the vibration significantly. As a result, a half vehicle model that includes the first two beamings of the frame can satisfy the vehicle vibration analysis precision requirements. Driver ride quality was evaluated according to ISO2631 1.     

Quantitative evaluation of all terrain vehicle mobile platform vibration

对3种气调保鲜箱贮藏环境的气体成分变化及对杨梅保鲜效果进行了研究.试验结果表明,在0℃冷藏条件下,使用气调保鲜箱杨梅适宜贮藏时间为20天,保鲜效果明显好于对照;气调箱-2效果最好.气调箱-2在贮藏6天时O2、CO2含量达到平衡;在贮藏12～15天时CO2含量达到峰值20.65%,O2含量接近2%,该环境条件有利于杨梅贮藏保鲜.     

Dynamic characteristic analysis of an all terrain vehicle body

The body is a key part of all terrain vehicles (ATV). Its dynamic characteristics greatly effect the vibration of the ATV assembly. Simulation and experimental methods are combined to analyze ATV body vibration characteristics. A computer aided design(CAD) model is built using UG4.0. A finite element method(FEM) model of an ATV body and a body with an engine are created using Hypermesh. The FEM model is imported to Msc.Nastran to calculate the free mode. The simulation model is verified by the experimental modal result. The results indicate that after the frame with engine, the first bending mode increases due to the engine increasing the body stiffness, while the first torsion mode decreases due to the engine mass. The effects on the dynamic response of the road and engine excitation are analyzed respectively. Vibration characteristic improvement methods and suggestions regarding the body are provided.     

simulation and improvement of an all terrain vehicle muffler

Aiming at a muffler of a 400 all terrain vehicle(ATV), a vibration model and an acoustics model of the muffler were built by finite element method(FEM). The vibration and acoustics characteristic analysis of the muffler are carried out according these models, it shows the 3D model is exact and it is possible to generate regeneration noise. Acoustics model can help to know further about the characteristic of each chamber and intention of the designer. According the demand of factory, some projects of improvement are offered. The final result of road test proves that he improved muffler is feasible.     

Subjective Evaluation of Motorcycle Ride Comfort

The ride comfort of more than ten representative motorcycles is evaluated by the r. m. s acceleration value through road test. Then the investigation on ride comfort, with five grades, is carried out through these motorcycles rode by a dozen drivers. Using statistics and fuzzy mathematical methods, the fuzzy evaluation model of motorcycles ride comfort is built to discuss the relationship between the vibration magnitude and human reaction. Finally, according to this model, two motorcycles ride quality are evaluated.     

Design of Analysis and Evaluation Application System for Ride Comfort

The stimulation and the optimal design for bus ride comfort have played an importable roles in design and reform of automobile products. The new vibration comfort coefficient is applied to evaluate the ride comfort of automobile, and the software is developed. It is verified that the study has theoretical and practical value significantly.     

热湿工况下工位辐射空调的热舒适实验研究

为研究热湿工况下使用工位辐射空调的人体热舒适情况,在人工环境实验室内,通过改变环境背景温度来影响人体的热感觉,并采用热感觉投票（TSV）作为评价标准,重点研究了人体头部、躯干、上肢、下肢以及整体热感觉情况。实验结果表明,尽管背景环境参数超出舒适范围,但使用工位辐射空调能维持受试者的舒适状态,即背景温度稳定在28 ℃时,平均整体热感觉投票值低于+0.2;背景温度为30 ℃时,受试者热感觉仍能满足ASHRAE规范中规定的80%可接受范围要求。     

Coordinated torque control strategy for driving-mode-switch of strong hybrid electric vehicle

For a new type of strongly hybridized system, the vehicle ride performance is used as the study goal, a coordinated control strategy is put forward to suppress the torque surge after the analysis of the parameters changes of engine, motor, clutch and transmission during the driving-mode-switch process. The strongly hybridized vehicle simulation model is developed based on the coordinated control strategy. The typical drive mode switching process performance simulation and analysis are performed. The results show that introducing the coordinated control strategy reduces the torque surge during the driving-mode-switch process and improves the vehicle drivability.     

Improvement of vehicle air-conditioning duct and analysis of its impact on occupant thermal comfort

A numerical simulation on the air flow in vehicle air-conditioning duct is conducted by applying computational fluid dynamics（CFD）code Fluent and its result is compared to test result within a very small difference. Besides, the result shows that the distribution of air flow is so uneven that the thermal comfort of driver is rather poor. To improve it, the air-conditioning duct system is optimized by response surface methodology which took three structural dimensions of the deflector attached to it as design variables and considered the airflow ratio of the driver side and the overall airflow as optimized purposes, and then the thermal comfort analysis of the driver was performed to the improved air-conditioning system. As a result, the airflow ratio of the driver side is improved to 51.3% from 44.9% due to the optimized air-conditioning duct, as well as that the thermal comfort of the driver is obviously improved.     

Study on Ride Comfort of Motorcycle Based on Virtual Prototyping

A kind of useful virtual dynamic model of motorcycle is established with dynamic analysis software ADAMS. Some related key problems regarding dynamical modeling is researched. By inputting road load spectrum, the ride comfort of motorcycle is analyzed and the simulating results are evaluated. Based on the evaluating results, the strength of front and rear damping springs are optimized and the performance of the redesigned product is improved.     

应用STATCOM的DFIG风力发电机低电压穿越能力分析

针对DFIG（double fed induction generator）风电机组低电压穿越能力（LVRT,low voltage ride through）问题,笔者基于STATCOM研究了一种电压外环与电流内环相结合的双闭环反馈控制策略,并仿真验证了所提出方法的有效性。将STATCOM分别安装风电机组机端、并网点高压侧和低压侧,且设置不同电压跌落深度,比较其补偿效果。实验结果表明,安装在风电机组机端时补偿效果最好。在电网电压跌落时,STATCOM能快速为电网输入无功,抬高风力机的机端电压,从而提高风电场的LVRT能力,从STATCOM输出无功大小和风电场机端电压被抬升的比例两方面分析,对于不同深度的电压跌落,STATCOM补偿效果都较为显著。     

Fuzzy Comprehensive Evaluation of Human Thermal Comfort

The human thermal comfort is influenced by many factors, and it is fuzzy, so it is a kind of stochastic fuzzy variable. So the evaluation of human thermal comfort is fuzzy also. and the method assessing the human thermal comfort with fuzzy mathematics is reliable. The factor affecting the human thermal comfort is analysed and predigested. Based on the analysis above,the methodology of assessing the thermal comfort is presented. The methodology resolves the decision_making continuum, so it lightens uncertainty of traditional method. The simulation results are compared with the Predicted Mean Vote index, and they are in good agreement. The study shows that the methodology of assessing the thermal comfort is reliable,and it presents a new approach for studying the human thermal.     

青海乡域中小学教室内学生冬季的热舒适性

对青海乡域4所典型中小学校10间教室冬季室内温湿度、风速、黑球温度等热环境参数进行现场测试,同时对420余名青少年学生的衣着情况、热感觉评价等进行了主观问卷调查。对测试和调查结果进行统计分析,得到实测和预测热中性温度分别为13.8和14.5℃,热期望温度为16.2℃,90%的学生感到满意的舒适温度范围为15.8~18.7℃。在当地寒冷的气候条件、学生衣着习惯、心理期望及生理特性等因素影响下,中小学生形成了对偏冷环境的适应性,提出可利用适应性PMV模型（aPMV）对中小学生平均热感觉进行准确预测。可为乡域中小学教室冬季热环境设计提供依据。     

The Simulation of Comfort of Nine DOF of Automobile

Automobile comfort dynamic simulation is necessary when we predict and evaluate the comfort of a automobile or optimize performance of automobile. The nine DOF vibration model of automobile is established , which acts root mean square value of body in multiple work conditions as comfort evaluation indices. Based on the comfort simulation, the Hongyan 1160 is predicted in the way of comfort. The programmes can be used in many different automobiles . The computational result indicates that the model can simulate vibration of automobile truly. It is significant to research automobile comfort evaluation to optimize performance of automobile and comfort simulation .The computational program can be applied to optimize or simulate which has some reference value.     

Simulation analysis on braking system of hybrid vehicle with ISG

A hydraulic braking system of the hybrid vehicle is designed based on braking force distribution and brake pressure coordination control strategy of integrated startor and generator(ISG) hybrid electric vehicle(HEV). Simulation model of hydraulic braking system has been established using AMESim software platform. Dynamic performance simulation and analysis to the key components and systems are performed. The results verify the correctness and feasibility of system program and provide evidence for designing and optimizing of HEV braking system.     

Objective evaluation methods of automobile riding comfort

There is much difference between GB4970 1996 Method of random input running test Automotive ride comfort and international evaluation methods, and the characters of automobile riding comfort is not discussed in detail. The measurement and evaluation methods are discussed. The ten axis vibrations exposed to human body in automobile are measured throughout road testing, and then the characteristic of automobile riding comfort is analyzed. An objective measurement and evaluation method of automobile riding comfort are presented. The results show that the difference generated by frequency weighting factors ωk and ωb is very little. The crest factor of vibration in automobiles is about 4~8 by time domain analysis. The percentage of each axis vibration is calculated, the results show that vertical vibration (z axis) at seat surface, horizontal vibration (x axis) at backrest and pitch vibration (rx axis) at seat surface are most important for comfort. The evaluation method in GB4970 1996 underestimates the vibration expose on the human body about 3 dB, which should be revised. Based on the results, a simple and convenient method for measuring vibration on automobiles is presented.     

The optimization for vibration comfort of commercial vehicle cab based on road test

The vibration comfort of commercial vehicle is improved in two ways where the data for the road-test are used as excitation and validation signals. The cab structure is optimized in HYPERMESH.At different speeds,acceleration RMS of the driver’s seat is reduced by 6% on average compared with the previous structure in ADAMS. In terms of the cab suspension,a multi-body dynamics model based on flexible cab is built. Taking the acceleration RMS as the evaluation target,the orthogonal test for optimizing the stiffness and damping of the suspension is conducted in the frequency domain. The different dynamic deflections are compared in time domain..At different speeds,acceleration RMS of the driver's seat is reduced by 10% on average after optimization of the cab suspension,dynamic deflection is reduced by 21% on average.     

Simulation analysis of control strategy for electric power steering system

The mathematical model of the electric power steering (EPS) system is developed,and control strategy is designed by the way of frequency analysis using Bode diagram,on a basis of steering feel expression．A complete model used for analysis of automotive steering characteristic,with four tire and three freedom vehicle models is built．In order to meet optimal goals,including steering agility,return ability and steering effort requirements of drivers, the rule of controller parameter values under the condition of different speeds and steering torques is concluded through numerous simulation tests．     

Simulation analysis of the thermal-electric analogy calculation model of transformer winding hot-spot temperature

The winding hot-spot temperature is one of the most critical parameters that determines the power transformer overloading capability and the aging rate of the oil-paper insulation. Based on the traditional thermal theory, the paper proposes a simulation model to predict transformer winding hot spot temperature taking into account oil viscosity changes with temperature, and combined with the thermal-electric analogy method and hot spot temperature rise model recommended by IEEE. The Runge-Kutta method is used to calculate top-oil temperature and winding hot-spot temperature of the transformer, and then compare them with the measured data obtained from the 100 kVA/5 kV (ONAN) experimental transformer. The simulation results are in good agreement with experimental data.     

Application of Index Evaluation Method: an Interior Integrated Evaluation to Business Halls of China Construction Bank in Shenzhen

From the view of clients and staffs of China Construction Bank in Shenzhen,through establishing comfort index by Likert scale,an integrated evaluation on the comfort of the business halls is carried out by questionnaire.It was shown that there were several factors affecting the interior design: for clients,the sense of comfort involved temperature,atmosphere quality,illumination,dimension of furniture and spaciousness etc.,but the staffs more cared for the crowded degree of indoor environment and the comfort of furniture.The research shows that the Methods of Index Evaluation are easy for handling and transverse comparison.