Study of Suspension Parameters Matching to Enhance Vehicle Ride Comfort on Bump Road

In this study, the parameters of the MacPherson front suspension and the E-type multilink rear suspension are matched to enhance the vehicle ride comfort on bump road. Vehicle vibration and suspension stiffness are analyzed theoretically. In the simulation study, the influence of the front and rear wheels on the vehicle vibration is considered, so the time-domain curves of the front and rear seat rail accelerations are processed by adding windows with two different window functions. The resulting ΔRmsLocal and ΔRmsGlobal are used as evaluation indexes of the vehicle ride comfort. The sensitivity analysis yields the magnitude of the influence of the suspension parameters on the evaluation indexes. In addition, the trends of ΔRmsLocal and ΔRmsGlobal with bushing stiffness at different vehicle speeds are discussed. The results show that longitudinal ΔRmsLocal and ΔRmsGlobal of the seat rails are influenced by the bushings mostly, while the vertical ΔRmsLocal and ΔRmsGlobal of the seat rails are influenced by the spring and shock absorber mostly. The trends of ΔRmsLocal and ΔRmsGlobal with bushing stiffness are influenced by the speed of the vehicle. Finally, the vehicle ride comfort is enhanced after optimization and matching of the suspension parameters by NSGA-II optimization algorithm.

DYNAMIC ANALYSIS OF BOGIE WHEELSET- A REVIEW

The dynamic of railway vehicle wheelsets is influenced by the actions of the conicity of the wheels and the creep forces acting between the wheels and rails. In this review paper, the dynamics analysis of wheelset has investigated, equations of motion have formulated and stability criteria obtained which indicate the effects of varying the various parameters of the system. The nature of the motion at the critical speed is investigated and the mode of energy conversion between the forward motion of the vehicle and the lateral motion of the wheelset is explained. From a dynamic analysis, it is shown how the critical speed of the wheelset slips and suspension stiffness relates to the kinematic motion.

Possibility of using gas lubricant in the cylinders of internal combustion engines of transport vehicles

The prospects of using the gas-static suspension of the internal combustion engine piston in transport vehicles and power plants are considered. The diagram of the piston and the method for calculating the stiffness and bearing capacity of the gas layer surrounding the piston are presented, as well as the results of experiments that showed the relevance of this method. The possibility of gas and static centering of the engine piston is confirmed. Keywords: internal combustion engine, piston, gasstatic suspension, stiffness, bearing capacity, gas medium. [email protected]

Selection of the characteristics of the suspension system of the high-speed tracked robot

Currently, the field of mechanical engineering is rapidly developing, including the creation of robotic high-speed vehicles. The design of suspension systems for such vehicles must be accompa-nied by the fulfillment of certain requirements, which are currently not formulated. Considering the thing that there is no person in the body of a high-speed robot, the application of the requirements for the suspensions of crew vehicles is not justified. In order to develop recommendations on the choice of characteristics of suspension systems for high-speed tracked robots, the research objects, which mass is in the range from 1000 to 10000 kg are determined. No suspension system is required for objects weighing less than 1000 kg. Objects weighing more than 10,000 kg will be created on the basis of existing serial vehicles. The study is based on the provision that the considered class of vehicles is not subject to re-strictions on the range of natural frequencies of body vibrations. Considering that one of the main requirements remains for high-speed tracked robots - ensuring a high average speed, it is proposed to increase the suspension stiffness in order to exclude resonance from the range of possible travel speeds. Using the accepted provisions, a study of the suspension system of increased stiffness is carried out. The movement along the tracks of a harmonic profile in resonance mode and a broken dirt road is simulated. The results of the study show that the characteristics of the suspension system, selected accord-ing to the proposed method, make it possible to move along the line of the harmonic profile in the resonant mode without suspension breakdowns. The speed of movement on a broken dirt road is limited to a value, which exceeding leads to sig-nificant vibrations of the body and an increase in the load on the elements of the suspension system. The absence of breakdowns leads to a decrease in the loading of the suspension, which makes it possible to reduce the mass of its elements.

Inverse Filtering for Frequency Identification of Bridges Using Smartphones in Passing Vehicles: Fundamental Developments and Laboratory Verifications

This paper puts forward a novel methodology of employing inverse filtering technique to extract bridge features from acceleration signals recorded on passing vehicles using smartphones. Since the vibration of a vehicle moving on a bridge will be affected by various features related to the vehicle, such as suspension and speed, this study focuses on filtering out these effects to extract bridge frequencies. Hence, an inverse filter is designed by employing the spectrum of vibration data of the vehicle when moving off the bridge to form a filter that will remove the car-related frequency content. Later, when the same car is moving on the bridge, this filter is applied to the spectrum of recorded data to suppress the car-related frequencies and amplify the bridge-related frequencies. The effectiveness of the proposed methodology is evaluated with experiments using a custom-built robot car as the vehicle moving over a lab-scale simply supported bridge. Nine combinations of speed and suspension stiffness of the car have been considered to investigate the robustness of the proposed methodology against car features. The results demonstrate that the inverse filtering method offers significant promise for identifying the fundamental frequency of the bridge. Since this approach considers each data source separately and designs a unique filter for each data collection device within each car, it is robust against device and car features.

Quantitative Research on Contribution Degree of Vibration Affecting Factors of Vehicle Suspension System Based on Robustness Analysis

Suspension system is the key component affecting vehicle ride comfort and finding out the main factors affecting suspension system vibration is the precondition of controlling suspension system vibration and improving vehicle comfort. Based on the principle of robustness analysis, the robustness analysis process of suspension system vibration influencing factors is constructed, in order to solve the problem, the three levels of front suspension stiffness, front suspension damping, rear suspension stiffness and rear suspension damping are selected, the experiment design scheme is adopted, power Spectrum of Class A road is used as input excitation source for suspension system simulation, the weighted acceleration root mean square simulation experiment of suspension system vibration under the influence of multiple factors is carried out.

Architecture and Optimization of a Low-Frequency Maglev Energy Harvester

Low-frequency harvesters are attractive due to their availability in the ambient environment. The paper presents the design, analysis and optimization of the magnetic levitation harvester. A new nonlinear model of the electromechanical coupling, depending on the magnet position versus coil is proposed. Additionally, the influence of magnetic suspension (stiffness), load resistance and magnet-coil configuration on the foldover effect is shown.

Analisis Getaran Kendaraan Sistem Satu Roda dalam tinjauan Dua Derajat Kebebasan

The comfort of the vehicle passenger of the vehicle and its stability are the important variables that are always needed by everyone who uses transportation. In order to achieve this goal, the suspension of the vehicle will play an important role because its function is to isolate passengers from the effects of excitation from outside the vehicle and also to control the wheels attached to the road surface. Therefore in this study, the influence of various types of suspensions on vehicle vibrations is observed in terms of comfort and stability. The type of suspension in this study is related to the level of suspensión stiffness namely the spring and the damper. Vehicle modeling to be applied in a one-wheeled vehicle with two degrees of freedom. The experimental study is conducted by loading of vehicle body weight and passengers to three type of suspension, soft, medium and hard. Vibration responses to be analyzed on the vehicle equation using Matlab to obtain the acceleration response of the displacement and the defelction. This research obtains a vibration response graph for each type of suspension for some kind of road profile.