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A vehicle must be designed in such a way that it guarantees its occupants safety and comfort in the face of various situations, such as a sudden lane change, something that can happen at any time during a trip or even a military operation. In this situation, the car must react to this excitement without compromising the car's stability. In this context, the present work aims to study the application of semi active suspension with magnetorheological dampers assisted by an embedded electronics system in order to improve the dynamic behavior of the vehicle, whose suspension springs are modeled in a non-linearly way using polynomials. To this end, this study performs an analysis of the vertical and lateral dynamics of a 4 x 4 vehicle with 10 degrees of freedom. The model construction uses the power flow methodology to establish the relationship between the kinematics and the dynamics of the chassis.

The combat cars design seeks to balance mobility and fire power, in order to enable the vehicle to shot with accuracy, although running on rough roads. The gun follows the chassis movement, as well as the cannon shots produce forces that change the car dynamics. Because of that, the suspension system of military vehicles has not only to reduce the oscillations caused by the terrain but also has to damper the gun recoil after each shot, preventing misalignment between the tube and the target. Therefore, the present study goal is to evaluate how semiactive dampers could reduce the chassis pitch motion of the Armored Personnel Carrier 6x6 Guarani, from the Brazilian Army, equipped with magnetorheological dampers, while running on a rough road and shooting with the 30 mm cannon at the same time. The proposed model uses the power flow concept to establish the kinematics relationships of the vehicle subsystems, and thus determinate the causality relationships among the components.

The suspension system of a vehicle has the main objective of dampening the transmission of irregularities in the terrain to the chassis. This is necessary to preserve the vehicle's internal components and to ensure greater comfort for the occupants of the car. For that, several studies were carried out in the area, proposing modifications in the passive and active suspensions, resulting in a greater dynamic stability of the vehicle. In military vehicles, the importance of these studies grows as they have larger dimensions and a greater mass, making damping more difficult. Analyzing this damping will be the basis for analyzing of this paper. Whose main analysis tool will be the improvement in performance by replacing the traditional passive suspension by a magnetorhelogic active suspension. For this, a MATLAB / Simulink model will be used by means of a block diagram.

The purpose of this work is to model the dynamics of a three-dimensional three-axle vehicle subjected to certain excitations from the ground and considering the geometry and inertia of the suspension elements according to the “kinematic transformers” method. The chassis is considered a rigid body with six degrees of freedom (three positions and rotations). The tire is a compliant element, which receives vibration from the ground and transmits to the wheel. Unlike simpler computational models, which make a direct connection between the wheel and the chassis by means of a spring and damper, the influence of the suspension geometry and inertia of its elements are considered. In this case of study, the suspension studied is the independent MacPherson in each wheel, although the methodology would be applied to other kind of suspensions, once its geometry is known. The kinematic transformers method is applied to study the cinematics of the suspension.

While traveling on any type of ground, the damper of a vehicle has the critical task of attenuating the vibrations generated by its irregularities, to promote safety, stability, and comfort to the occupants. To reach that goal, several passive dampers projects are optimized to embrace a bigger frequency range, but, by its limitations, many studies in semiactive and active dampers stands out by promoting better control of the vehicle dynamics behavior. In the case of military vehicles, which usually have more significant dimensions than the common ones and can run on rough or unpaved lands, the use of semi-active or active dampers reveals itself as a promising alternative. Motivated by that, the present study performs an analysis of the vertical dynamics of a wheeled military vehicle with four axles, using magnetorheological dampers. This study is made using a configuration of the distances between the axles of the vehicle, which is chosen from five available options.

The ride comfort study has become increasingly important in vehicle designs. This paper analyzes the ride comfort of an all-wheel drive (AWD) vehicle on different types of pavements. The modeling process of an AWD vehicle is presented at this work, as well as a brief discussion of the international standards on evaluation of human exposure to whole-body vibration (WBV). Numerical simulations of the vertical vehicle dynamics, considering ride quality, are performed in different types of pavements. Accuracy, efficiency and efficacy in all cases are compared to the limits set by international standards for whole-body vibration. Throughout this process, the performance of a light vehicle suspension system is validated within the established limits.

In this work, an inverse problem approach is employed to estimate the suspension parameters of a light vehicle based on field tests. The modeling process of a rear-wheel drive (RWD) vehicle is depicted. The model considers only the vertical dynamics of the vehicle. The experimental data were measured by sensors installed on the vehicle during specific road tests in a proving ground. The inverse problem is solved by using the Particle Swarm Optimization (PSO), minimizing the quadratic error between experimental data and numerical results of the vehicle simulation. Accuracy, computational time, efficiency and efficacy of the model were compared regarding the behavior of the performance responses of the vehicle measured on the road tests. Throughout this process, the vehicle model was validated to be used in future studies of vehicle dynamics.

This paper uses an inverse problem approach to estimate parameters of a tire model based on Julien’s Theory (JT). The modeling process of an all-wheel drive (AWD) vehicle is presented in this work, as well as JT and Pacejka’s Magic Formula (MF) tire models. Numerical simulations of the longitudinal vehicle dynamics, considering MF, provide pseudo-experimental data to the inverse problem. Particle Swarm Optimization (PSO), Random Restricted Window (R2W) and Differential Evolution (DE) are used to estimate the parameters of the JT tire model. Accuracy, computational time, efficiency and efficacy of the models are compared regarding the behavior of the performance responses of the vehicle. Throughout this process, Julien’s Theory is validated for use in future studies of vehicle dynamics.