Designs and optimizations of active and semi-active non-linear suspension systems for a terrain vehicleShpetim Lajqi
, Stanislav Pehan
, 2012, izvirni znanstveni članek
Opis: This paper introduces a design and optimization procedure for active and semi-active non-linear suspension systems regarding terrain vehicles. The objective of this approach is the ability to quickly analyze vehicles' suspension performances resulting from passive, active, or semi-active systems. The vehicle is represented by a mathematical model regarding a quarter of it, and equations for motion are derived and solved by using MATLAB/Simulink. In order to verify the reliability of the derived computer program, a comparison is made with one of the comprehensive commercial software packages. The decision parameters of the active damping device are optimized by using the Hooke-Jeeves method, which is based on non-linear programming. The usefulness of the treated active and semi-active systems on a concrete terrain vehicle is presented and compared with the presented passive systems by analyzing the vehicle's body acceleration, velocity, displacement, and vertical tire force, namely those aspects that directly influence driving comfort and safety.
Ključne besede: terrain vehicles, vehicle design, suspension system, semi-active
Objavljeno v DKUM: 10.07.2015; Ogledov: 901; Prenosov: 115
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Design of independent suspension mechanism for a terrain vehicle with four wheels drive and four wheels steeeringShpetim Lajqi
, Stanislav Pehan
, Naser Lajqi
, Afrim Gjelaj
, Jože Pšeničnik
, Sašo Emin
, 2013, izvirni znanstveni članek
Opis: In this paper a terrain vehicle with four wheels drive and four wheels steer intended to use for recreational purpose is presented. The main purpose is to design the suspension mechanism that fulfills requirements about stability, safety and maneuverability. Nowadays, as well as in the past, the development of the suspension systems of the vehicle has shown greater interest by designers and manufacturers of the vehicles. Research is focused to do a comprehensive study of different available independent suspension system (MacPherson, double wishbone, multi-link) and hence forth develop a methodology to design the suspension system for a terrain vehicle. Few chosen suspension systems are analyzed into the very details in order to find out the optimal design of it. During development process of the suspension system should be considered design constraints and requirements provided in the checklist. Afterwards the simulation results for kinematics analyses of suspension mechanism are performed in Working Model 2D and MATLAB environments. Achieved results are discussed in detail in order to find the best solution that will fulfill pretentious requirement from developed suspension system. All these investigations and reviews related to the suspension system will be exploited in order to obtain the optimal suspension geometry to equip a terrain vehicle, with such system.
Ključne besede: terrain vehicle, design, suspension mechanism, suspension geometry
Objavljeno v DKUM: 10.07.2015; Ogledov: 1357; Prenosov: 67
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SUSPENSION AND STEERING SYSTEM DEVELOPMENT OF A FOUR WHEEL DRIVE AND FOUR WHEEL STEERED TERRAIN VEHICLEShpetim Lajqi
, 2013, doktorska disertacija
Opis: The key goal of doctoral thesis was to conceive, design, optimize, and analyze the suspension and steering systems for a four wheel drive and four wheel steered terrain vehicle. The common characteristic of a terrain vehicle is the greater motion of the wheels in order to protect the vehicle from rollover risk when running over rough terrain. Known suspension and steering systems have serious weaknesses. In order to ensure good driving comfort, efficient driving safety, and higher maneuverability, new principles of suspension and steering systems are proposed.
The proposed suspension system has been successfully derived from a classical double wishbone control arm. The control arms are long but both equal. Greater wheel motion has been ensured without reducing driving performance. In order to improve the comfort and safety an optimal active damping force has been determined by the active and semi-active systems. On the basis of comprehensive analysis, active system adequacy has been achieved. The proposed suspension design provides relatively small lateral wheel motion, zero camber angles, and it effectively absorbs the vibrations caused by ground configurations.
The goal of the developed steering system for this terrain vehicle was to design a new steering mechanism that would provide maneuverability at low speed and suitable stability at higher speed. This has been ensured by two modes of steering, all wheel steer and front wheel steer. The proposed steering mechanisms conform to Ackermann steering geometry for all modes and situations. A totally new steering concept has been developed. This effective design consists of special pairs of gears, known as’ non-circular gears’.
Ključne besede: Terrain vehicle, suspension system, steering system, four wheels steering
Objavljeno v DKUM: 18.03.2013; Ogledov: 3864; Prenosov: 394
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