scholarly journals Fuzzy Hybrid Control of Off-Road Vehicle Suspension Fitted With Magnetorheological Dampers

Author(s):  
W. G. Ata ◽  
S. O. Oyadiji

The vibration caused by severe road excitation influences off-road vehicle suspension performance. The vibration control of the suspension system is a crucial factor for modern vehicles. Smart control devices (magnetorheological dampers) are proposed as a first step to handle a multiple suspension system of off-road vehicles. The magnetorheological (MR) dampers can be employed as smart dampers for vibration suppression of the suspension system; this is done by varying the produced damping force. In this paper an investigation is presented on the effectiveness of such smart dampers in attenuating the vibration of a multiple suspension system. This goal is accomplished by designing a new fuzzy hybrid controller and studying its effectiveness on the suspension performance. The multiple suspension system considered here comprises a chassis, five wheels and three MR dampers. The chassis is suspended over the five wheels through five compression springs. Three MR dampers are attached to the first, second and the fifth wheel. The stiffness of the wheels is represented by five compression springs. Only the bounce and the pitch of the chassis are considered. The assessment of the proposed model is carried out through a simulation scheme under bump and sinusoidal excitations in the time domain. The excitation of the five wheels is done independently. The simulation is accomplished using the MATLAB/SIMULINK software. The simulation results show the effectiveness and robustness of the new controller in conjunction with MR dampers in vibration suppression. Compared to the passive suspension, the body bounce, body displacement, angular acceleration and pitch angle can be well controlled.

2021 ◽  
pp. 107754632110396
Author(s):  
Fei Ding ◽  
Jie Liu ◽  
Chao Jiang ◽  
Haiping Du ◽  
Jiaxi Zhou ◽  
...  

The vibration suppression of the proposed pitch-resistant hydraulically interconnected suspension system for the tri-axle straight truck is investigated, and the vibration isolation performances are parametrically designed to achieve smaller body vibration and tire dynamic load using increased pitch stiffness and optimized pressure loss coefficient. For the hydraulic subsystem, the transfer impedance matrix method is applied to derive the impedance matrix. These hydraulic forces are incorporated into the motion equations of mechanical subsystem as external forces according to relationships between boundary flow and mechanical state vectors. In terms of the additional mode stiffness/damping and suspension performance requirements, the cylinder surface area, accumulator pressure, and damper valve’s pressure loss coefficient are comprehensively tuned with parametric design technique and modal analysis method. It is found the isolation capacity is heavily dependent on installation scheme and fluid physical parameters. Especially, the surface area can be designed for the oppositional installation to separately raise pitch stiffness without increasing bounce stiffness. The pressure loss coefficients are tuned with design of experiment approach and evaluated using all conflict indexes with normalized dimensionless evaluation factors. The obtained numerical results indicate that the proposed pitch-resistant hydraulically interconnected suspension system can significantly inhibit both the body and tire vibrations with decreased suspension deformation, and the tire dynamic load distribution among wheel stations is also improved.


1978 ◽  
Vol 100 (3) ◽  
pp. 500-506 ◽  
Author(s):  
E. Esmailzadeh

The suspension system of a vehicle provides the means by which forces and movements are transferred from the body to the wheels and vice versa. While the general outline of vehicle suspension behavior is fairly well known, little interest has been shown in the detailed dynamic performance of the various components. Air springs are perhaps the most versatile and adaptable type of suspension element. They provide practically frictionless action, adjustable load capacity and simplicity of height control. Initially, a vehicle suspension system with a pneumatic isolator connected to a fixed volume tank via parallel plate restrictor is considered. Here the damping is provided by the flow of air through the restricted passage which has an advantage over the conventional viscous shock absorber. Body movements are only considered to be vertical harmonic displacement. An optimization technique is applied to evaluate the optimum values of many parameters involved for which the maximum transmitted motion to the body would be minimum over the broad frequency range. Theoretical expressions for the transmissibility of the body and the wheel, optimum values of mass ratio, stiffness ratio and damping ratio are presented. Design data are presented nondimensionally for parameter variations which are sufficiently broad to encompass a wide range of practical engineering problems.


Author(s):  
Jahangir Rastegar ◽  
Kavous Jorabchi ◽  
Hee J. Park

In recent studies, a new class of planar and spatial linkage mechanisms was presented in which for a continuous full rotation or continuous rocking motion of the input link, the output link undergoes two continuous rocking motions. Such linkage mechanisms were referred to as the “motion-doubling” linkage mechanisms. This class of mechanisms was also shown to generally have dynamics advantage over regular mechanisms designed to achieve similar gross output motions. In the present study, the use of the motion-doubling linkage mechanisms in the construction of vehicle suspension systems is investigated. The performance of the resulting vehicle suspension system is compared to that of a suspension system regularly used in vehicles. For a typical set of vehicle and tire parameters, the parameters of both suspension systems are optimally determined with a commonly used objective function, which is defined as the standard deviation of the vertical acceleration of the vehicle. Using numerical simulation, it is shown that the suspension system constructed with a motion-doubling linkage mechanism has a significantly better performance as compared to a standard suspension system.


2011 ◽  
Vol 148-149 ◽  
pp. 516-519
Author(s):  
Jun Tao Fei ◽  
Jing Xu

This paper attempts to establish the vibration control technology based on neural network control. First, the dynamic model of vehicle suspension system is discussed, and the linear passive suspension model and nonlinear spring suspension model of the vertical acceleration are compared. It is shown that the performance of nonlinear spring suspension is better than that of the linear passive suspension model. Because of the great advantages of the neural network in dealing with the nonlinear property, secondly, model reference neural control module is introduced in the suspension system to realize the optimization of the body vertical acceleration. Simulation results demonstrate the effectiveness of the neural network adaptive controller with application to vehicle suspension.


2011 ◽  
Vol 383-390 ◽  
pp. 2012-2017 ◽  
Author(s):  
Guo Quan Yang ◽  
You Qun Zhao

In this paper, a semi-active suspension system has been proposed to improve the ride comfort, and a 2 DOF vehicle system is designed to simulate the actions of vehicle suspension system. The purpose of a suspension system is to support the vehicle body and increase ride comfort. The aim of the work described in the paper was to illustrate the application of fuzzy logic technique to the control of a continuously damping automotive suspension system. The ride comfort is improved by means of the reduction of the body acceleration caused by the car body when road disturbances from smooth road and real road roughness. Based on MATLAB fuzzy control toolbox, fuzzy controller is designed. Simulation analysis of suspension system is preceded by using MATLAB/Simulink7.0. The result shows that this control can improve the body acceleration, suspension distortion etc.


1999 ◽  
Vol 33 (sup1) ◽  
pp. 3-22 ◽  
Author(s):  
Massimiliano Gobbi ◽  
Giampiero Mastinu ◽  
Carlo Doniselli ◽  
Luca Guglielmetto ◽  
Enrico Pisino

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