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.     

Simulation and analysis of all terrain vehicle ride comfort

A multi rigid body dynamic model of an all terrain vehicle (ATV) is established in MSC.ADAMS. The model takes into consideration the body, suspension, frame and the steering system. According to the method of superposition of harmonic wave, a Grade B road file is created in ADAMS for the riding comfort test. The engine excitation is analyzed. The infliction for engine excitation to ADAMS is achieved. The ATV ride comfort simulation is carried out with the excitation of the engine, and the seat vibration is evaluated using an evaluation method programmed via MATLAB. It has laid a good foundation for further analysis.     

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.     

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.     

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.     

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.     

Analysis of Fuzzy Control Strategy Based on Energy and Peak Value of Vibration

The effect of damping on vibration is analyzed during the suspension deformation based on the 1/4 vehicle model. The Fuzzy logic control strategy for the semi-active suspension was proposed. By means of dissipating the energy of vibration and decreasing the peak value of the body acceleration via the action of damping, the parameter-self-adjust fuzzy controller was established. The united simulation of ADAMS and Matlab/Simulink were used for demonstrating the efficiency of the controller. Comparing with the practical passive suspension possessing the nonlinear character and the present fuzzy controller, the control system based on the new-style strategy provides better ride comfort and road handling.     

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.     

插电式混合动力汽车纯电动行进间启动发动机的平顺性控制

针对单电机插电式混合动力汽车在纯电动行进间电动机启动发动机时由于系统输出转矩变化进而引起整车冲击的问题,分析得到发动机点火时刻的不同及离合器接合状态的不同是造成转矩波动的原因。在此基础上,提出了基于离合器主、从动盘转速差和电机角加速度为输入量的离合器压力模糊控制的混合动力汽车模式切换动态协调控制策略,并对比了发动机目标转速点火和怠速转速点火的控制效果。最后通过台架试验以及实车道路试验对提出的控制策略进行了验证。结果表明,基于目标转速点火的协调控制策略能减小整车的冲击度。     

Monitoring of Vibration Exposure for Taxi Drivers

Vibration Exposure of taxi driver has not only impact on driverg health but the safety of driving. The constantspeed running test and a monitoring test in actually situationare done. The taxi driver vibration exposure testing data is analyzed, and it is found that the vibration exposure evaluation of constant speed test cant satisfy the actually situation. At last, animpersonalassessment is done according to the vibration exposure evaluation standard of ISO2631.     

Discussion on the Application Range of the PMV Equation

With the attention to the comfort degree of living environment, the phenomenon of making use of the PMV -PPD index within the ISO7730 standard to evaluate the indoor thermal comfort degree is more and more widespread. Many papers about indoor thermal environment are based on the PMV - PPD index as the reference or basis to research and analyze. But few people understand and pay attention to the application range of the PMV - PPD index. So some people misuse and abuse the PMV index and deduce some inaccurate conclusions. In this thesis, based on the analysis of the process of deducing PMV equation, the phenomenon that PMV index is different from the fact in the high temperature condition is explained; furthermore the application range of the PMV equation is confirmed. So to obtain the scientific and reasonable evaluation and conclusion in the process of research of the thermal comfort degree can be ensured.     

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.     

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.     

体育馆大跨度预应力次梁楼盖竖向振动模态分析

以重庆市铜梁县新城核心区小学建设项目3^#楼（体育馆）工程为背景,对其大跨度预应力次梁楼盖竖向振动模态进行模拟分析,并与实测结果相比较,评价其控制竖向振动舒适度的效果。根据建模思路精确建立的该大跨楼盖有限元模型,其模态分析结果与模态实测结果接近,相对误差约为5%;模拟分析及工程实测结果表明,该大跨楼盖前三阶振型均以竖向振动为主,结构自振基频满足我国现行相关规范的要求,竖向振动舒适度符合标准;与无底板的大跨次梁楼盖相比,增加底板后,其增幅最小的一阶频率增长了19.9%,表明增加底板可有效地控制大跨度预应力次梁楼盖的竖向振动。     

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.     

Analysis of Low frequency Noise of Bridge Considering the Vibration of Bridge Deck

Under the dynamic load of vehicle, the bridge will vibrate and radiate low frequency noise which is harmful to human health. A method for predicting the low frequency noise is proposed based on the analysis of vibration of bridge deck. The prediction includes the analysis of vehicle bridge coupling vibration considering the bridge deck and the analysis of sound radiation and propagation in the air. By taking a bridge with low frequency noise as example, the vibration and sound radiation of the bridge are analyzed respectively by the current method and the previous method based on the grillage model. The results show that the prediction based on the vibration of bridge deck is more accurate. Furthermore, the measures to reduce the noise of bridge are explored, and the results indicate that a smoother road surface leads to lower noise. But when the condition of road surface is up to the extremely good standard defined by ISO, the effect of reducing the roughness of surface is not significant. Also, strengthening the crossbeam in the bridgehead is a simple and effective way to reduce the low frequency noise of bridge.     

Fuzzy Control of Vehicle Semi- active Suspension System via Magneto- rheological Fluid Damper

A quarter - car suspension system in which the MR fluid dampers are used as the semi - active control actuators has been proposed and developed based on the theory analysis of MR fluid dampers characteristic. A adaptive fuzzy logic controller is developed. The completed system is simulated via SIMULINK Toolbox of MATLAB 6.1. Compared to the passive suspension system and simple fuzzy logic controller, the adaptive fuzzy logic controller markedly reduces the vertical acceleration of the sprung mass and effectively improves ride comfort of automobile.     

Robust H control for vehicle seat suspension systems with stochastic disturbance

The paper proposes the design method of robust H controller of vehicle seat suspension system. The dynamic model of seat suspension is developed,and the parameters uncertainties (mass, stiffness, damping) and stochastic vibration are introduced into the model system. Based on stochastic differential theory and Lyapunov functional, a semi controller is designed, and the controller parameters are solved by linear matrix inequality (LMI) which guarantees H performance index. The simulation results in time domain and frequency domain show that the controller designed for parameter uncertainties and stochastic vibration can attenuate the vertical acceleration of suspension system and improve riding comfort of human.     

1961-2015年青海省西宁市旅游气候舒适度评价

为解决西宁市旅游资源评价和旅游舒适度预报问题,基于1961—2015 年的地面气象观测资料,计算重点旅游城市度假、人体舒适度、温湿指数的月和年序列资料,利用气候诊断方法分析评估其特征及其变化。结果表明,近55 年青海省西宁市夏季舒适日数呈显著的上升趋势,上升速率为1.1 d/10 a,舒适平均日数为89 天。西宁夏季的寒冷、温湿、度假、人体舒适度指数位于适宜-舒适级别和很适宜-最舒适级别,夏季西宁旅游或居住的气候条件舒适程度与昆明、贵阳、兰州、银川相当。夏季西宁适合旅游度假和休闲养生的气候关联指标在重点旅游城市中占据了优势,而这种优势在近10 年显现得更加明显。评估结果为青藏高原相关部门开展旅游舒适度预报和西宁市旅游气候资源的综合开发提供科学依据。     

基于累积时数的夏季人居环境舒适度评判模型研究—以宁波市为例

舒适度是人居环境的重要评判指标。利用宁波市1957-2016年逐日气象数据和2005-2016年逐时气象数据,对宁波市夏季舒适度变化特征及其对气温要素的响应进行分析,开展了基于舒适等级累积时数的日舒适度评判模型研究。结果表明：宁波市60a夏季舒适日数年际间波动变化不明显,但夏季不舒适日开始时间提前趋势明显;舒适度指数日变化与气温日变化趋势相似,13时最不舒适;宁波市夏季舒适日数与平均气温、平均最低气温、平均最高气温、极端最高气温和高温日数显著相关;利用线性拟合结果,建立了基于舒适等级累积时数的宁波市夏季日舒适度评判模型,对模型分别进行历史资料回代模拟和2016年一致性验证,舒适和不舒适等级历史回代一致率较高,2016年模型验证中各等级一致率均在91.7%以上,表明新模型评判效果较好,能够满足业务服务需求。