scholarly journals Study of Viscoelastic Rubber Mounts on Vehicle Suspensions with In-Wheel Electric Motors

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3356
Author(s):  
Santiago D. Puma-Araujo ◽  
Renato Galluzzi ◽  
Xavier Sánchez-Sánchez ◽  
Ricardo A. Ramirez-Mendoza
Keyword(s):  
Viscoelastic Model ◽  
Sensitivity Analyses ◽  
Nonlinear Stiffness ◽  
Automotive Applications ◽  
Rubber Material ◽  
Interface Elements ◽  
Vehicle Suspensions ◽  
Suspension Systems ◽  
Filtering Effect ◽  
Selection Of

Rubber bushings and mounts are vastly used in automotive applications as support and interface elements. In suspension systems, they are commonly employed to interconnect the damping structure to the chassis. Therein, the viscoelastic nature of the material introduces a desirable filtering effect to reduce mechanical vibrations. When designing a suspension system, available literature often deals with viscoelastic mounts by introducing a linear or nonlinear stiffness behavior. In this context, the present paper aims at representing the rubber material using a proper viscoelastic model with the selection of different in-wheels motors. Thus, the mount dynamic behavior’s influence in a suspension is studied and discussed thoroughly through numerical simulations and sensitivity analyses. Furthermore, guidelines are proposed to orient the designer when selecting these elements.

scholarly journals Applications of Approximate Optimal Control to Nonlinear Systems of Tracked Vehicle Suspensions

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Yan-Jun Liang ◽  
You-Jun Lu ◽  
De-Xin Gao ◽  
Zhong-Sheng Wang
Keyword(s):  
Optimal Control ◽  
Vibration Control ◽  
Ride Comfort ◽  
Nonlinear Dynamic System ◽  
Active Suspension ◽  
Nonlinear Damping ◽  
Tracked Vehicle ◽  
Control Approach ◽  
Vehicle Suspensions ◽  
Suspension Systems

AbstractTechnique of approximate optimal vibration control and simulation for vehicle active suspension systems are developed. Considered the nonlinear damping of springs, mechanical model and a nonlinear dynamic system for a class of tracked vehicle suspension vibration control are established and the corresponding system of state space form is described. To prolong the working life of suspension system and improve ride comfort, based on the active suspension vibration control devices and using optimal control approach, an approximate optimal vibration controller is designed, and an algorithm is presented for the vibration controller. Numerical simulation results illustrate the effectiveness of the proposed technique.

Robust Controller Design for Active Suspension Systems of Road Vehicles

2017 ◽  
Author(s):  
Shenjin Zhu ◽  
Yuping He
Keyword(s):  
Controller Design ◽  
Operating Conditions ◽  
Ride Quality ◽  
Vehicle Model ◽  
Linear Quadratic ◽  
Robust Controller ◽  
Baseline Design ◽  
Vehicle Suspensions ◽  
Suspension Systems ◽  
Active Suspension Systems

The Linear Quadratic Gaussian (LQG) technique has been applied to the design of active vehicle suspensions (AVSs) for improving ride quality and handling performance. LQG-based AVSs have achieved good performance if an accurate vehicle model is available. However, these AVSs exhibit poor robustness when the vehicle model is not accurate and vehicle operating conditions vary. The H∞ control theory, rooted in the LQG technique, specifically targets on robustness issues on models with parametric uncertainties and un-modelled dynamics. In this research, an AVS is designed using the H∞ loop-shaping control, design optimization, and parallel computing techniques. The resulting AVS is compared against the baseline design through numerical simulations.

scholarly journals Evolution of the China Railway Express Consolidation Network and Optimization of Consolidation Routes

2019 ◽  
Vol 2019 ◽  
pp. 1-16
Author(s):  
Laijun Zhao ◽  
Zhaolin Cheng ◽  
Huiyong Li ◽  
Qingmi Hu
Keyword(s):  
Complex Network ◽  
Network Evolution ◽  
Profit Margin ◽  
Sensitivity Analyses ◽  
Load Factor ◽  
Belt And Road Initiative ◽  
Management Implications ◽  
Low Load ◽  
Belt And Road ◽  
Selection Of

China Rail Express (CRE) is the international container train line that runs between China and Europe. Since the implementation of China’s Belt and Road initiative, CRE has developed rapidly. As most CRE trains travel directly from source to destination without load consolidation, CRE faces issues such as an insufficient cargo supply, a low load factor, and a low profit margin. To address these problems, we analyzed the selection of potential consolidation centers and the optimization of consolidation routes to these centers from the perspective of complex network evolution. First, we constructed rules for generation and evolution of the complex network. Next, we generated logistics connection topology networks for CRE from 2013 to 2017 using those rules. We then optimized the consolidation routes based on the network structures formed from those rules. Chongqing, Xi’an, Chengdu, Zhengzhou, Shenyang, Lanzhou, Urumqi, and Tianjin were selected as potential consolidation centers. We conclude with a sensitivity analyses and a discussion of management implications for CRE.

An Accurate Full Car Ride Model Using Model Reducing Techniques

2002 ◽  
Vol 124 (4) ◽  
pp. 697-705 ◽  
Author(s):  
Chul Kim ◽  
Paul I. Ro
Keyword(s):  
Model Complexity ◽  
Ride Quality ◽  
Singular Perturbation Method ◽  
Suspension Systems ◽  
Proposed Model ◽  
Model Size ◽  
Improved Performance ◽  
Accurate Matching ◽  
Multibody Dynamics Model ◽  
Selection Of

In this study, an approach to obtain an accurate yet simple model for full-vehicle ride analysis is proposed. The approach involves linearization of a full car MBD (multibody dynamics) model to obtain a large-order vehicle model. The states of the model are divided into two groups depending on their effects on the ride quality and handling performance. Singular perturbation method is then applied to reduce the model size. Comparing the responses of the proposed model and the original MBD model shows an accurate matching between the two systems. A set of identified parameters that makes the well-known seven degree-of-freedom model very close to the full car MBD model is obtained. Finally, the benefits of the approach are illustrated through design of an active suspension system. The identified model exhibits improved performance over the nominal models in the sense that the accurate model leads to the appropriate selection of control gains. This study also provides an analytical method to investigate the effects of model complexity on model accuracy for vehicle suspension systems.

scholarly journals Application of Hexagonal Fuzzy MCDM Methodology for Site Selection of Electric Vehicle Charging Station

Mathematics ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 393
Author(s):  
Arijit Ghosh ◽  
Neha Ghorui ◽  
Sankar Prasad Mondal ◽  
Suchitra Kumari ◽  
Biraj Kanti Mondal ◽  
...  
Keyword(s):  
Electric Vehicle ◽  
Site Selection ◽  
Distance Measure ◽  
Multiple Criteria Decision Making ◽  
Sensitivity Analyses ◽  
Analytic Hierarchy ◽  
Charging Station ◽  
Electric Vehicle Charging ◽  
Vehicle Charging ◽  
Selection Of

In this paper, the application of hexagonal fuzzy multiple-criteria decision-making (MCDM) methodology for the site selection of electric vehicle charging stations is considered. In this regard, four factors and thirteen sub-factors have been taken into consideration for E-vehicle charging site selection. In this research, the geographic information system (GIS) has been incorporated with MCDM techniques. The fuzzy analytic hierarchy process (FAHP) is used to obtain a fuzzy weight of factors and sub-factors. MCDM tools fuzzy technique for order of preference by similarity to ideal solution (FTOPSIS) and fuzzy complex proportional assessment (FCOPRAS) have been used to rank the selected sites. A centroid-based method for defuzzification and distance measure between two hexagonal fuzzy numbers (HFN) has been developed for this paper. A practical example in Howrah, India, is considered to show the applicability and usefulness of the model. The results depict the suitability of the proposed research. Comparative and sensitivity analyses have been demonstrated to check the reliability, robustness and effectiveness of the proposed method.

scholarly journals Tailoring Strongly Nonlinear Negative Stiffness

2013 ◽  
Vol 136 (2) ◽  
Author(s):  
F. Liu ◽  
S. Theodossiades ◽  
D. M. McFarland ◽  
A. F. Vakakis ◽  
L. A. Bergman
Keyword(s):  
Negative Stiffness ◽  
Nonlinear Stiffness ◽  
Stability Properties ◽  
Strongly Nonlinear ◽  
Or Groups ◽  
Forcing Functions ◽  
Linear Spring ◽  
Reduced Space ◽  
The Stability ◽  
Selection Of

Negative, nonlinear stiffness elements have been recently designed as configurations of pairs or groups of linear springs. We propose a new design of such a system by using a single linear spring with its moving end rolling on a path described by an equation of varying complexity. We examine the effect that the selection of the path has on the size of the deflection regime where negative stiffness is achieved. The stability properties of the equilibrium positions of the system are also investigated, highlighting the influence that the complexity of the path equation brings. The latter naturally affects the characteristics of the forcing functions around these positions. It is demonstrated that the properties of the system can be tailored according to the nature of the equation used and we show how essentially nonlinear negative stiffness elements, (i.e., with no linear parts) can be designed. These results provide a useful standpoint for designers of such systems, who wish to achieve the desired properties in reduced space, which is a common requirement in modern applications.

Pharmacoeconomics for Dermatologists: An Introduction

1997 ◽  
Vol 1 (3) ◽  
pp. 185-189
Author(s):  
Aditya K. Gupta ◽  
Paul I. Oh ◽  
Neil H. Shear
Keyword(s):  
Health Care ◽  
Medical Literature ◽  
Treatment Options ◽  
Decision Makers ◽  
Sensitivity Analyses ◽  
Economic Evaluations ◽  
Therapeutic Decision ◽  
Therapeutic Decision Making ◽  
Care Decision ◽  
Selection Of

Background: The budgets available for health care are becoming constrained and health care decision makers have increasingly begun to scrutinize cost along with efficacy, tolerability, and cost of the different treatment options for each disease state. In keeping with the above, there has been a marked increase in the number of pharmacoeconomic evaluations published in the medical literature, including dermatology journals. Methods: Comprehensive economic evaluations systematically consider the following: statement of question, defining relevant costs, perspective and time-horizon, synthesis of data on efficacy and effectiveness, and selection of the appropriate analytic type and framework. The conclusions should be tested through extensive sensitivity analyses. Conclusions: Economic evaluations are becoming more prevalent in the field of dermatology. A well-constructed analysis may be an aid to more rational therapeutic decision-making.

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

2021 ◽  
Vol 1 (2) ◽  
pp. 63-70
Author(s):  
YE.B. Sarach ◽  
◽  
YA.A. Tkachev ◽  
M.E. Krokhin ◽  
◽  
...  
Keyword(s):  
High Speed ◽  
Natural Frequencies ◽  
Resonant Mode ◽  
Suspension System ◽  
The Body ◽  
Suspension Systems ◽  
A Value ◽  
Dirt Road ◽  
Suspension Stiffness ◽  
Selection Of

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.

Comparative Study on the Hysteresis Performance of the Metal Rubber Vibration Isolating Bearing with Different Height-Width Ratio Parameter

2014 ◽  
Vol 1079-1080 ◽  
pp. 191-194
Author(s):  
Yan Guo Zhou ◽  
Jian Jiang
Keyword(s):  
Seismic Isolation ◽  
Shear Stiffness ◽  
Width Ratio ◽  
Damping Capacity ◽  
Dynamic Shear ◽  
Rubber Material ◽  
Model Method ◽  
Metal Rubber ◽  
Hysteresis Properties ◽  
Selection Of

A new kind of Metal Rubber material vibration isolating bearing is developed and the MR bearings with three different height-width ratio are manufactured. The dynamic shear hysteresis properties of the MR bearings are tested. The theoretical dynamic model method is adopted for the comparative analysis. The experimental results shows that with the H-W ratio decrease, the effective shear stiffness and the effective damping capacity of MR vibration isolating bearing will increase, and the total energy dissipation increases greatly. The selection of the H-W ratio of the MR vibration isolating bearing become an important issue in the structural seismic isolation design.

scholarly journals A novel stiffness model for a wall-climbing hexapod robot based on nonlinear variable stiffness

2018 ◽  
Vol 10 (1) ◽  
pp. 168781401775248 ◽  
Author(s):  
Bin He ◽  
Shoulin Xu ◽  
Zhipeng Wang
Keyword(s):  
Structural Parameters ◽  
Variable Stiffness ◽  
Load Force ◽  
Nonlinear Stiffness ◽  
Hexapod Robot ◽  
Maximum Stiffness ◽  
Stiffness Model ◽  
Linear And Nonlinear ◽  
Serial Mechanism ◽  
Selection Of

In this article, the most contribution is to propose a novel general stiffness model to analyze the stiffness of a wall-climbing hexapod robot. First, we propose a new general stiffness model of serial mechanism, which includes the linear and nonlinear stiffness models. By comparison, the nonlinear stiffness model is a variable stiffness model which introduces the external load force as a variable, obtaining that the nonlinear stiffness model can greatly improve the accuracy of stiffness model than linear stiffness model. Then, the stiffness model of one leg of the robot and the overall stiffness model of the robot are derived based on the general stiffness model. Next, to improve the stiffness of the robot, a new minimum and maximum stiffness are introduced, which provide with effective reference for the selection and optimization of the structural parameters of the robot. Finally, we develop a new wall-climbing hexapod robot based on selection and optimization of the structural parameters, then the experiments are used to show that the selection of structure parameters of the robot effectively improve the stiffness of the robot.

Sign in / Sign up

Export Citation Format

Share Document