Study On Ride Comfort Based On A Car

Cars have become necessities of each family with the rapid development of China's automobile industry.Ride comfort has become an important reference while consumers plan to buy a car.Cars with better ride comfort will be competitive in automotive markets.Vehicle ride comfort is not only related to passengers' comfort and security but also related to the goods' completeness when the car is used as a means of transportation.Thus,now ride comfort design has been regarded as an important part in automotive research and development processes.This paper focuses on the study of the evaluation method for static and dynamic comfort based on a car.First,the establishment of three dimensional model of Chinese adults for ergonomics analysis.We chose Chinese adults'measurement data based on body dimensions of existing national standard,estimated some Chinese adults' dimensions data with the model of regression equations,and did some amendment on several dimensions related to clothing state based on the real driving condition.Then we established body dimensions database files,and after imported the files into CATIA the human body model was generated.Second,study of static comfort with fuzzy comprehensive evaluation method.Made human models ride on seat model with loop interference detection method,then joints angle values collection of different gender and body percentile could be extracted in CATIA.We established three-level of gender,body percentile,and joint angle fuzzy evaluation model and programmed fuzzy comprehensive evaluation in Matlab.In order to make a fully evaluation of static comfort of the car,we did some work to check its vision and hand reach scope.Third,after discussed common methods for establishment of bio-mechanical vibration model of human body we built four degrees model of freedom upper body systems.In regards of pros and cons of various kinds of models nine degrees of freedom model for"human-vehicle-Chair" dynamic system was established.The partial differential equations of motion were built with the application of Lagrange's equations method,and at last,we set up corresponding Simulink models according to the equations.Finally,based on the enhanced features and functionality of Simulink dynamic simulation,we obtained vibration response of the various parts of the body after simulation with the input of road roughness random excitation.Simulation results indicated that the vibration comfort of body in the car was getting worse with the increase of road roughness and vehicle speed in time-domain analysis;And the frequency domain analysis results has shown that the resonance frequency is matched with the driving point impendence standard;Finally we drew a conclusion according to the root mean square of acceleration of parts of the human body that vibration comfort of the target vehicle is good.Static and dynamic comfort evaluation results in this paper indicated that methods of evaluation used in the text to can be used to evaluate the target car's ride comfort quickly and effectively.Quick evaluation of riding comfort in the vehicle development process,particularly in reverse engineering,can provide good feedback to comfort design,reduce the design cycle,and has a certain practical value.