Car Suspension

The study demonstrates a significant advancement in vehicle suspension testing by utilizing the Taguchi method for optimization. The suspension system determines a vehicle’s performance, directly affecting ride comfort, handling, and safety. The research presented in this study highlights a potentially effective method for enhancing suspension testing. The research systematically investigates the complex network of factors influencing suspension behavior using the Taguchi method, a robust optimization technique. The analysis includes examining road surface conditions, passenger weight variations, and tire pressure fluctuations. The objective is to design a suspension system that provides both comfort and stability without making any concessions, regardless of the obstacles encountered on the road. The car utilized for this research is an Altis sedan equipped with tires with a 205/55 R16 profile. The study’s findings indicate that factor A, which represents embankment height, signifi...

The study demonstrates a significant advancement in vehicle suspension testing by utilizing the Taguchi method for optimization. The suspension system determines a vehicle’s performance, directly affecting ride comfort, handling, and safety. The research presented in this study highlights a potentially effective method for enhancing suspension testing. The research systematically investigates the complex network of factors influencing suspension behavior using the Taguchi method, a robust optimization technique. The analysis includes examining road surface conditions, passenger weight variations, and tire pressure fluctuations. The objective is to design a suspension system that provides both comfort and stability without making any concessions, regardless of the obstacles encountered on the road. The car utilized for this research is an Altis sedan equipped with tires with a 205/55 R16 profile. The study’s findings indicate that factor A, which represents embankment height, signifi...

It can be considered that the suspension system is one of the most important systems in the VEHICLE. Where it is responsible for the stability and balance of the vehicle’s structure on the roads and curves to ensure the comfort of passengers. Also, it absorbs the shocks resulting from the unevenness of the road and prevents it from reaching the wheelhouse. The influence of the suspension constructive parameters in order to obtain the smallest level of displacements of the sprung mass has been investigated. The following control parameters are the stiffness of the sprung, unsprung mass, and the damping of the sprung mass. The parameter which affects most displacements of the sprung mass was determined by applying the analysis of variance (ANOVA). The investigation was conducted using MATLAB/SIMULINK software, and a line model of a quarter of the vehicle was created. It was determined that the stiffness of sprung has the most significant influence on the displacement of the sprung-mas...

The study demonstrates a significant advancement in vehicle suspension testing by utilizing the Taguchi method for optimization. The suspension system determines a vehicle’s performance, directly affecting ride comfort, handling, and safety. The research presented in this study highlights a potentially effective method for enhancing suspension testing. The research systematically investigates the complex network of factors influencing suspension behavior using the Taguchi method, a robust optimization technique. The analysis includes examining road surface conditions, passenger weight variations, and tire pressure fluctuations. The objective is to design a suspension system that provides both comfort and stability without making any concessions, regardless of the obstacles encountered on the road. The car utilized for this research is an Altis sedan equipped with tires with a 205/55 R16 profile. The study’s findings indicate that factor A, which represents embankment height, signifi...

The aircraft is a means of transportation that operates mainly in the air; however, it starts and ends its journey on the ground. Due to the aircraft’s structural complexity, simulation tools are used to understand and to predict its behavior in its movements on the ground. Simulation tools allow adjusting the observation parameters to gather a greater amount of data than real tests and explore interactions of the aircraft and their individual components with external objects such as pavement imperfections. This review aims to collect information on how to simulate the aircraft interaction with traffic-dependent energy harvesting systems. The specifications and framework to be met by a conceptual design are explored. The different configurations for simulating the aircraft configuration result in the selection of the two-mass-spring-damper model. For the components, especially the landing gear, a deployable element for on-ground movements, several existing models capable of translat...

The aircraft is a means of transportation that operates mainly in the air; however, it starts and ends its journey on the ground. Due to the aircraft’s structural complexity, simulation tools are used to understand and to predict its behavior in its movements on the ground. Simulation tools allow adjusting the observation parameters to gather a greater amount of data than real tests and explore interactions of the aircraft and their individual components with external objects such as pavement imperfections. This review aims to collect information on how to simulate the aircraft interaction with traffic-dependent energy harvesting systems. The specifications and framework to be met by a conceptual design are explored. The different configurations for simulating the aircraft configuration result in the selection of the two-mass-spring-damper model. For the components, especially the landing gear, a deployable element for on-ground movements, several existing models capable of translat...

I certify that this thesis satisfies the requirements as a thesis for the degree of Master of Science in Mechanical Engineering. Assoc. Prof. Dr. Uğur Atikol Chair, Department of Mechanical Engineering I certify that I have read this thesis and that in our opinion it is fully adequate in scope and quality as a thesis for the degree of Master of Science in Mechanical Engineering.

The pneumatic elastic elements are widely used in the secondary suspension of modern railway vehicles due to their important advantages compared to the conventional ones. In the present paper, the modelling and analysis of the pneumatic suspension is approached, taking into account the main elements, pneumatic enclosures and rubber elements. The analysis performed investigates the influence of relevant parameters on suspension stiffness and on its dynamic response.

Suspension system is the necessary part in the automobile vehicle. Suspension system provide comfort ride to the passengers. Suspension system absorbs the unnecessary vibration which applied on the upward from road irregularities. Here in this paper we will find deflection of existing car with the existing suspension system and going to modified suspension system and find deflection for modified design. Also, we are going to compare deflection for existing and modified design.

This study aims to examine more about the effect of vertical dynamic load of vehicles and changes in dimensional barriers on the road surface in its path. Experimentally this fluctuating load is replaced by a pneumatic force change based on the regulation of air pressure on the regulator. The deviations generated by the varying load work are measured by placing a proximity sensor along the spring movement. The amount of vertical load transformation reaches the road surface is measured by using Load cell. Characteristics of vertical dynamic vibration occurring due to several dimensional barriers, U (cm) obtained using mathematical modeling method with 2 DOF suspension system transfer function.  The results showed a condition on the body and wheels of vehicles experienced a brief overshot for 0.14 seconds with deviation of 0.178 m. From the graph shows that the rate of deviation that occurs is large enough that Y2d = 1.03 m / s caused by a sudden shock that occurred on the wheels of t...

This paper gives an insight on the suspension dynamics of the two most widely used models for vehicle dynamics with their complete state space analysis, simulated by using Mat Lab platform. In this paper we investigate the responses of the quarter car and a half car model as the vehicle ride performance is generally assessed at the design stage by simulating the vehicle response to road excitation. This requires the development of a vehicle model to analysis its responses. The time responses and frequency responses of the sprung and unsprung masses have been studied. The optimal solution here is the damping, which has been optimized with the given set of fixed parameters.

The pneumatic elastic elements are widely used in the secondary suspension of modern railway vehicles due to their important advantages compared to the conventional ones. In the present paper, the modelling and analysis of the pneumatic suspension is approached, taking into account the main elements, pneumatic enclosures and rubber elements. The analysis performed investigates the influence of relevant parameters on suspension stiffness and on its dynamic response.

Vibration are harmful in number of ways to machines and equipment. To control vibration, study and analysis is pivotal. Vibration protecting mechanisms or Vibration Isolators are designed based on analysis of vibration behaviour. MATLAB computer program is used in this research to fulfil the design and analysis goals. A Mathematical Model is developed, which defines system and provides output in terms of isolator properties based on input signal. MATLAB is known for its applications in all of engineering fields. A script in MATLAB is used for input signal processing and equation solving and another Simulink model is used for simulation and comparison of optimized solution. In this research mechanical theories, mathematics, calculus, signal processing tools and knowledge of MATLAB program are applied.

Active and semi-active control of oscillating devices and structures is a challenging field and this paper proposes an original investigation based on variational controls that can be successfully applied to mechanical systems. The method produces a general class of new controllers, named VFC -Variational Feedback Controllers, that is the main theoretical contribution of the paper. The value of the theory relies on using a reformulation of the Variational Optimal Control Theory, that has in general the limit of producing control program strategies and not directly feedback control methods. The difficulties are in fact related to the intrinsic nature of the variational optimal control, that must solve initial and final boundary conditions. A special definition of the class of the considered objective functions, permits to skip this difficulty, producing a pure feedback control. The presented theory goes beyond with respect to the most acknowledged LQR variational-based techniques, in that VFC can be applied to more general nonlinear dynamical systems, even with finite time horizon. To test the effectiveness of the novel approach in real engineering problems, a deep investigation on nonlinear suspension systems treated by VFC is proposed in this paper. To this aim, VFC is systematically compared with the most recent methods available in this field and suitable to deal with nonlinear system control of car suspensions. In particular, the comparative analysis is made in terms of both comfort and handling key performance indexes, that permits to easily and significantly compare different control logics, such as the Sky-hook and Ground-hook control families, the Acceleration and Power Driven Dampers. The results of this comparison are collected in a performance plane, having comfort and handling indexes as coordinate axes, showing that VFC controllers completely cover the regions reached by the other mentioned control logics in this plane, but reveal to have access to new valuable areas of unexplored different performance combinations.

The basic purpose of a damper is to reduce the vibration and to have a better ride comfort, road handling and safety to the rider. Recent developments show that an active vibration damper can effectively work much better than a passive damper. The effectiveness and reliability can be further enhanced by using hybrid dampers, which is a combination of active and passive dampers. But the need to have energy optimization in any field need not be stressed. Consequently, novel suspension concepts are required, not only to improve the vehicle's dynamic performance, but also to see that the energy generated during vibration can be harvested by utilizing regeneration functions. Hence if a hybrid damper with energy harvesting capability be designed, it would serve both purposes. In the hybrid damper a combination of hydraulic damper to act as a passive damper and an electromagnetic (EM) damper to act as an active damper is considered. The hydraulic system has more reliability and is time tested and the EM system acts as a dynamic vibration system as well as energy harvester. In this study a hybrid EM damper is modeled, analyzed and validity is shown for frequency response functions and energy balance for its active use. It is also shown how the effectiveness of the suspension system can be enhanced by using a hybrid damper.

This paper investigates the GENSIS air spring suspension system equivalence to a passive suspension system. The SIMULINK simulation together with the OptiY optimization is used to obtain the air spring suspension model equivalent to passive suspension system, where the car body response difference from both systems with the same road profile inputs is used as the objective function for optimization (OptiY program). The parameters of air spring system such as initial pressure, volume of bag, length of surge pipe, diameter of surge pipe, and volume of reservoir are obtained from optimization. The simulation results show that the air spring suspension equivalent system can produce responses very close to the passive suspension system.

This study aims to examine more about the effect of vertical dynamic load of vehicles and changes in dimensional barriers on the road surface in its path. Experimentally this fluctuating load is replaced by a pneumatic force change based on the regulation of air pressure on the regulator. The deviations generated by the varying load work are measured by placing a proximity sensor along the spring movement. The amount of vertical load transformation reaches the road surface is measured by using Load cell. Characteristics of vertical dynamic vibration occurring due to several dimensional barriers, U (cm) obtained using mathematical modeling method with 2 DOF suspension system transfer function.  The results showed a condition on the body and wheels of vehicles experienced a brief overshot for 0.14 seconds with deviation of 0.178 m. From the graph shows that the rate of deviation that occurs is large enough that Y2d = 1.03 m / s caused by a sudden shock that occurred on the wheels of t...

Shock absorbers allow the damping of suspension vibrations, by dissipating kinetic energy. This energy theoretically can be harvested; however, practical solutions are not easily obtainable. This paper is dedicated to analyzing and evaluating the vibration energy in a vehicle's suspension that is generated by road excitations. Also, it estimates the possible amount of harvested energy required to diminish accelerations of the vehicle body, the driver, or the passenger center of mass. The control of damper is realized by optimizing the best damping coefficient for different road roughness. Analytical results, obtained from the proposed dynamic model of the car, were compared with experimental data, showing a good coherence between them. These results allow us to evaluate the amount of energy circulating within shock absorbers and give information about the amount of the possible harvested energy. There is a very good relationship between energy needed for control and gained energy.

This paper investigates the GENSIS air spring suspension system equivalence to a passive suspension system. The SIMULINK simulation together with the OptiY optimization is used to obtain the air spring suspension model equivalent to passive suspension system, where the car body response difference from both systems with the same road profile inputs is used as the objective function for optimization (OptiY program). The parameters of air spring system such as initial pressure, volume of bag, length of surge pipe, diameter of surge pipe, and volume of reservoir are obtained from optimization. The simulation results show that the air spring suspension equivalent system can produce responses very close to the passive suspension system.

This paper investigates the GENSIS air spring suspension system equivalence to a passive suspension system. The SIMULINK simulation together with the OptiY optimization is used to obtain the air spring suspension model equivalent to passive suspension system, where the car body response difference from both systems with the same road profile inputs is used as the objective function for optimization (OptiY program). The parameters of air spring system such as initial pressure, volume of bag, length of surge pipe, diameter of surge pipe, and volume of reservoir are obtained from optimization. The simulation results show that the air spring suspension equivalent system can produce responses very close to the passive suspension system.

This paper investigates the GENSIS air spring suspension system equivalence to a passive suspension system. The SIMULINK simulation together with the OptiY optimization is used to obtain the air spring suspension model equivalent to passive suspension system, where the car body response difference from both systems with the same road profile inputs is used as the objective function for optimization (OptiY program). The parameters of air spring system such as initial pressure, volume of bag, length of surge pipe, diameter of surge pipe, and volume of reservoir are obtained from optimization. The simulation results show that the air spring suspension equivalent system can produce responses very close to the passive suspension system.

As vibration control requirements become increasingly stringent, designers and users of vibration control equipment turn to devices and systems combining various physical mechanisms. Subsystems based on different physical effects can be combined to achieve the optimal performance for the application. Building an optimal product line that would cover a wide field of applications by combining several products, as opposed to creating one optimal device for a particular application, presents an optimum vibration control problem. This paper reviews optimum vibration control problems based on the idea of limiting performance, and discusses recent development of vibration control devices.

Pneumatic vibration isolation is the most widespread effective method for creating vibration-free environments that are vital for precise experiments and manufacturing operations in optoelectronics, life sciences, microelectronics, nanotechnology and other areas. The modeling and design principles of a dual-chamber pneumatic vibration isolator continue to attract attention of researchers. On the other hand, behavior of systems of such isolators was never explained in the literature in sufficient detail. After a brief summary of the theory and a model of a single standalone isolator, the dynamics of a system of isolators supporting a payload is considered with main attention directed to three aspects of their behavior: first, the static stability of payloads with high positions of the center of gravity; second, role of gravity terms in the vibration transmissibility; third, the dynamic stability of the feedback system formed by mechanical leveling valves. The direct method of calculating the maximum stable position of the center of gravity is presented and illustrated by three-dimensional stability domains. A numerical method for feedback stability analysis of self-leveling valve systems is provided, and the results are compared with the analytical estimates for a single isolator. The relation between the static and dynamic phenomena is discussed.

This paper deals with the theoretical aspects combined with experimental analysis regarding early damage identification in passive vibro-isolation devices. Basically, this research presents the relevant results obtained for a singular element. Rubber based on elements is discussed especially. This study was a naturally fall-back of the authors large analysis regarding the dynamic behaviour of the passive isolation devices against vibration, shocks and seismic waves. Main hypothesis supposed that on the exploitation time, all technical devices and systems acquire different levels of wearing because of the dynamic overloads and their derivative influences (aging, fatigue, energy dissipation, external heating or cooling, etc.). Hereby the performance characteristics changes and the system becomes working improperly. Numerical simulations were developed for simple spatial configuration of isolation device. Stochastic approach of essential results was briefly presented nearby the relevan...

The process of (modeling, simulation and control of linear quarter car active suspension system) is the proposed model in which the coil spring was replaced by air spring of the type of Nishimura and hydraulic damper with the use of air actuator getting to the final mathematical equalization which represent such model, aiming firstly to obtain (smart suspension system) the purpose behind is to have a better response for that systemization to active the best (handling, rid comfort and stability). The car through using such systemization and compare the response with the normal suspension systemization which are used in coil spring hydraulic damper and actuator whereas it is depended on the Displacement of the car body resulted from car effectiveness of the road circumstances as a standard in the process of outline the results from this paper with applying the rules of fuzzy controller that can be shown in item (IV).

The aim of this special issue was to gather specialists of different areas working on the nonlinear dynamics and vibration control of engineering problems. Due to the actual demands of the modern technology and the increasing slenderness of structural elements, it is unavoidable to take into account nonlinearities of the basic equations in their mathematical modeling. New phenomena in dynamics as well as new approaches to older ones are expected to be discovered in the theoretical, numerical and experimental investigations of these structures. The various current and potential applications of the knowledge about nonlinear systems in engineering sciences are being intensively demonstrated by ongoing research activities worldwide.

This paper investigates the effect of the calculation of the longitudinal location of a wheel rail contact point on the wheelset’s motion in a vehicle dynamic simulation. All current vehicle dynamic software programs assume that the contact between wheel and rail takes place in the vertical plane through the wheelset’s rolling axis. However, when the yaw angle of the wheelset is nonzero, the contact point is situated up to 10 mm from that plane. This difference causes a difference in the yaw moment on the wheelset which is used in the vehicle dynamic simulation. To such an end, an existing analytical method to determine the longitudinal method was validated using a numerical approach. Then vehicle dynamic simulations with both the classic and the new contact location were performed, concluding that using a more accurate contact point location results in a smaller wheelset yaw angle in a vehicle dynamic simulation, although the effect is small.

The air spring is one of the components that affects vehicle comfort. This element usually makes up the main part of the secondary suspension, which introduces both stiffness and damping between the bogie and the car body. Therefore, a deep understanding of this element is necessary in order to study the comfort of a vehicle, the influence of different parameters and the ways to improve it. In this work, the effect that the air spring system has on comfort is studied. To accomplish this, first a typical pneumatic suspension composition is briefly studied. Then, the test bench developed to study this system is described, presenting experimental results. Correlation of the results with some theoretical models is also addressed. Then, the effect of the air spring system on comfort is analysed and finally, it is discussed the improvements from introducing a variable area orifice in the pipe that joints the air spring and the surge reservoir.

This paper investigates the GENSIS air spring suspension system equivalence to a passive suspension system. The SIMULINK simulation together with the OptiY optimization is used to obtain the air spring suspension model equivalent to passive suspension system, where the car body response difference from both systems with the same road profile inputs is used as the objective function for optimization (OptiY program). The parameters of air spring system such as initial pressure, volume of bag, length of surge pipe, diameter of surge pipe, and volume of reservoir are obtained from optimization. The simulation results show that the air spring suspension equivalent system can produce responses very close to the passive suspension system.

Active and semi-active control of oscillating devices and structures is a challenging field and this paper proposes an original investigation based on variational controls that can be successfully applied to mechanical systems. The method produces a general class of new controllers, named VFC-Variational Feedback Controllers, that is the main theoretical contribution of the paper. The value of the theory relies on using a reformulation of the Variational Optimal Control Theory, that has in general the limit of producing control program strategies and not directly feedback control methods. The difficulties are in fact related to the intrinsic nature of the variational optimal control, that must solve initial and final boundary conditions. A special definition of the class of the considered objective functions, permits to skip this difficulty, producing a pure feedback control. The presented theory goes beyond with respect to the most acknowledged LQR variational-based techniques, in that VFC can be applied to more general nonlinear dynamical systems, even with finite time horizon. To test the effectiveness of the novel approach in real engineering problems, a deep investigation on nonlinear suspension systems treated by VFC is proposed in this paper. To this aim, VFC is systematically compared with the most recent methods available in this field and suitable to deal with nonlinear system control of car suspensions. In particular, the comparative analysis is made in terms of both comfort and handling key performance indexes, that permits to easily and significantly compare different control logics, such as the Sky-hook and Ground-hook control families, the Acceleration and Power Driven Dampers. The results of this comparison are collected in a performance plane, having comfort and handling indexes as coordinate axes, showing that VFC controllers completely cover the regions reached by the other mentioned control logics in this plane, but reveal to have access to new valuable areas of unexplored different performance combinations.

This paper analyses, from a control perspective, two physically different dampers for the semi-active control of ride: the magnetorheological damper (`conventional') and the friction damper (`non-conventional'). An in-depth analysis will show that the latter damper has modelling and control analogies with the magnetorheological damper and has the potential to be a low-cost alternative to a controlled viscous damper in particular areas of application. A general variable structure algorithm targeted to achieve ride control has been designed and implemented on both dampers. A variety of automotive applications have been investigated to offer a more well-rounded vision of the applicability of such dampers.

In this paper, a new strategy to design static output-feedback controllers for a class of vehicle suspension systems is presented. A theoretical background on recent advances in output-feedback control is first provided, which makes possible an effective synthesis of static output-feedback controllers by solving a single linear matrix inequality optimization problem. Next, a simplified model of a quarter-car suspension system is proposed, taking the ride comfort, suspension stroke, road holding ability, and control effort as the main performance criteria in the vehicle suspension design. The new approach is then used to design a static output-feedback ∞ controller that only uses the suspension deflection and the sprung mass velocity as feedback information. Numerical simulations indicate that, despite the restricted feedback information, this static output-feedback ∞ controller exhibits an excellent behavior in terms of both frequency and time responses, when compared with the corresponding state-feedback ∞ controller.

The paper had at least three topical way of reading. One was a proposal of a novel human motion trajectory principle. Second, it was a introduction of a way to enlarge the solution class of a given functional variation problem. Lastly, it was a description of a long left it's meanings never shown, the Lagrangian. In this document, we will try to give more insight into the second part.