scholarly journals Experimental attenuation and evaluation of whole body vibration for an off-road vehicle with magnetorheological dampers

2018 ◽  
Vol 38 (2) ◽  
pp. 852-870 ◽  
Author(s):  
Piotr Krauze ◽  
Jerzy Kasprzyk ◽  
Jaroslaw Rzepecki
Keyword(s):  
Ride Comfort ◽  
Health And Safety ◽  
Harmonic Excitation ◽  
Magnetorheological Damper ◽  
Vehicle Body ◽  
Whole Body ◽  
Magnetorheological Dampers ◽  
Passive Suspension ◽  
The Road ◽  
Damper Control

The paper presents an analysis of vehicle vibration, ride comfort and handling which have a decisive influence on health and safety of a driver. Experiments were carried out for a commercially available experimental all-terrain vehicle in the field in hard conditions with retaining the sufficient repeatability. The vehicle is equipped with a complex vibration control system, taking advantage of four automotive magnetorheological dampers. Numerous sensors, which measure acceleration in four points of the vehicle body, near the driver’s seat, feet and hands, body orientation in space and speed of vehicle wheels, are available in the vehicle. They were used for evaluation of magnetorheological dampers’ control signals and analysis of vibration affecting the driver. Constant values of magnetorheological damper control current were used for emulation of different settings of passive suspension. The analysis performed in frequency domain showed how vibration propagates in a medium-sized all-terrain vehicle and indicated that driver’s hands are mostly affected by the road-induced vibration. It was also confirmed that the greatest improvement of ride comfort can be obtained for the soft suspension, i.e. uncontrolled magnetorheological dampers. Furthermore, the Skyhook algorithm was implemented, including the proportional control of the magnetorheological damper force and the inverse Tanh model of the magnetorheological damper. It was validated for the wideband road-induced excitation contrary to the experiments commonly presented in the literature, which are performed only for harmonic excitation. It was shown that the properly tuned Skyhook algorithm enables improving vehicle handling compared to the passive suspension and simultaneously it can maintain the similar or even better results of ride comfort.

A semi-active vehicle suspension based on pneumatic springs and magnetorheological dampers

2016 ◽  
Vol 24 (4) ◽  
pp. 808-821 ◽  
Author(s):  
Angel L Morales ◽  
Antonio J Nieto ◽  
José M Chicharro ◽  
Publio Pintado
Keyword(s):  
Ride Comfort ◽  
Balance Control ◽  
Magnetorheological Damper ◽  
Pneumatic System ◽  
Magnetorheological Dampers ◽  
International Roughness Index ◽  
The Road ◽  
Pneumatic Suspension ◽  
Gps System ◽  
Curve Radius

Semi-active and active suspensions can improve both ride comfort and handling compared to passive suspensions. The authors have proposed a suspension comprising a pneumatic system capable of changing the stiffness of the suspension and a semi-active magnetorheological damper capable of controlling the suspension damping. Eight configurations of this magnetorheological/pneumatic suspension result from combining two possible stiffnesses (compliant and stiff) and four possible means of producing damping (constant low, constant high, on-off skyhook control and on-off balance control). The minimization of a cost function, which considers both ride comfort and handling, leads to decision maps which indicate the most appropriate configuration depending on vehicle velocity and two pieces of information about the road: the international roughness index and the curve radius. All this information can be gathered from a GPS system and toggling between set-ups is fast, efficient, and easily done by simply opening or closing pipes in the pneumatic system and modifying the current supply in the magnetorheological dampers. The proposed magnetorheological/pneumatic suspension achieves the same roll angle levels as in a comparable passive vehicle while improving ride comfort by reducing acceleration by up to 30%.

Self-powered magnetorheological dampers for motorcycle suspensions

2017 ◽  
Vol 232 (7) ◽  
pp. 921-935 ◽  
Author(s):  
Chao Chen ◽  
Yu Shing Chan ◽  
Li Zou ◽  
Wei-Hsin Liao
Keyword(s):  
Laboratory Testing ◽  
Ride Comfort ◽  
Mechanical Energy ◽  
The Self ◽  
Magnetorheological Damper ◽  
System Level ◽  
Magnetorheological Dampers ◽  
Suspension Systems ◽  
Magnetorheological Suspension ◽  
Self Powered

Dampers are the parts of suspensions which improve the ride comfort and the safety of vehicles including motorcycles. Magnetorheological dampers are very attractive for motorcycle suspensions, because of their controllable properties and their fast responses. Considerable energy is wasted owing to the energy dissipation by dampers encountering road irregularities and accelerating processes during everyday use of motorcycles. In addition, the current magnetorheological suspension systems depend on the power supply of batteries. Therefore, in this paper, a self-powered magnetorheological damper for motorcycle suspensions is proposed and implemented for the first time. It can convert the wasted mechanical energy into useful electrical energy to power itself. There are great merits in this such as energy saving, independence of extra batteries and less maintenance in comparison with conventional magnetorheological suspension systems, while keeping controllable performances. A customized prototype of the self-powered magnetorheological damper that is compatible with a motorcycle is developed and actually implemented in a motorcycle. Modelling for the self-powered magnetorheological damper is developed and validated by laboratory testing. Laboratory testing showed that the self-powered feature works well to generate the electrical power and to vary the magnetorheological damping force. Preliminary system-level testing showed that a self-powered magnetorheological suspension results in a better ride comfort, compared with that of a magnetorheological suspension without power generation. The results showed that implementing self-powered magnetorheological dampers in motorcycle suspensions is feasible and beneficial.

scholarly journals Mathematical Modelling of Two-Wheeler Suspension system in a wavy road

2019 ◽  
Vol 8 (11) ◽  
pp. 3630-3635
Keyword(s):  
Ride Comfort ◽  
Health Hazard ◽  
Suspension System ◽  
Vehicle Body ◽  
Continuous Exposure ◽  
Potential Health ◽  
Suspension Spring ◽  
The Road ◽  
Potential Health Hazard ◽  
Two Wheeler

Two wheelers like motorbikes and scooters are one of the major transports in India. In major cities and towns, it is most common private transport as it is fast and easy approach to the destination. But the prolonged drive in the two-wheeler leads to the potential health hazard and musco-skeletal disorder due to continuous exposure to the vibration caused during the ride and force transmitted to the vehicle body due to road irregularities. It is a challenge of automobile engineers to design a promising suspension system to overcome the risk of ride comfort during continuous driving. In this research, two-wheeler suspension system is modelled with a condition of bump and valley in a wavy road. The road surface is assumed to be wavy and the response of new suspension spring with different materials (stainless steel, tungsten and polymeric) along with viscous damper is analyzed and compared. By this analysis, it will be proposed to industry to modify the suspension system to improve its efficiency and reduce force transmitted to the human body to improve the ride comfort

Ride comfort of a higher speed rail vehicle using a magnetorheological suspension system

2017 ◽  
Vol 232 (1) ◽  
pp. 32-48 ◽  
Author(s):  
Sunil Kumar Sharma ◽  
Anil Kumar
Keyword(s):  
Ride Comfort ◽  
Suspension System ◽  
Magnetorheological Damper ◽  
Ride Quality ◽  
Railway Vehicle ◽  
Passive Suspension ◽  
Railway Vehicles ◽  
Rail Vehicle ◽  
Passive Suspension System ◽  
Secondary Suspension

In a railway vehicle, vibrations are generated due to the interaction between wheel and track. To evaluate the effect of vibrations on the ride quality and comfort of a passenger vehicle, the Sperling's ride index method is frequently adopted. This paper focuses on the feasibility of improving the ride quality and comfort of railway vehicles using semiactive secondary suspension based on magnetorheological fluid dampers. Equations of vertical, pitch and roll motions of car body and bogies are developed for an existing rail vehicle. Moreover, nonlinear stiffness and damping functions of passive suspension system are extracted from experimental data. In view of improvement in the ride quality and comfort of the rail vehicle, a magnetorheological damper is integrated in the secondary vertical suspension system. Parameters of the magnetorheological damper depend on current, amplitude and frequency of excitations. Three semi-active suspension strategies with magnetorheological damper are analysed at different running speeds and for periodic track irregularity. The performance indices calculated at different semi-active strategies are juxtaposed with the nonlinear passive suspension system. Simulation results establish that magnetorheological damper strategies in the secondary suspension system of railway vehicles reduce the vertical vibrations to a great extent compared to the existing passive system. Moreover, they lead to improved ride quality and passenger comfort.

Testing and Modeling of MR Damper and Its Application to SDOF Systems Using Integral Backstepping Technique

2009 ◽  
Vol 131 (2) ◽  
Author(s):  
Sk. Faruque Ali ◽  
Ananth Ramaswamy
Keyword(s):  
Active Control ◽  
Testing Machine ◽  
Mr Damper ◽  
Control Device ◽  
Magnetorheological Damper ◽  
Input Current ◽  
Magnetorheological Dampers ◽  
Damper Control ◽  
Nonlinear Devices ◽  
Current Monitoring

Magnetorheological dampers are intrinsically nonlinear devices, which make the modeling and design of a suitable control algorithm an interesting and challenging task. To evaluate the potential of magnetorheological (MR) dampers in control applications and to take full advantages of its unique features, a mathematical model to accurately reproduce its dynamic behavior has to be developed and then a proper control strategy has to be taken that is implementable and can fully utilize their capabilities as a semi-active control device. The present paper focuses on both the aspects. First, the paper reports the testing of a magnetorheological damper with an universal testing machine, for a set of frequency, amplitude, and current. A modified Bouc–Wen model considering the amplitude and input current dependence of the damper parameters has been proposed. It has been shown that the damper response can be satisfactorily predicted with this model. Second, a backstepping based nonlinear current monitoring of magnetorheological dampers for semi-active control of structures under earthquakes has been developed. It provides a stable nonlinear magnetorheological damper current monitoring directly based on system feedback such that current change in magnetorheological damper is gradual. Unlike other MR damper control techniques available in literature, the main advantage of the proposed technique lies in its current input prediction directly based on system feedback and smooth update of input current. Furthermore, while developing the proposed semi-active algorithm, the dynamics of the supplied and commanded current to the damper has been considered. The efficiency of the proposed technique has been shown taking a base isolated three story building under a set of seismic excitation. Comparison with widely used clipped-optimal strategy has also been shown.

scholarly journals Mixed Skyhook and FxLMS Control of a Half-Car Model with Magnetorheological Dampers

2016 ◽  
Vol 2016 ◽  
pp. 1-13 ◽  
Author(s):  
Piotr Krauze ◽  
Jerzy Kasprzyk
Keyword(s):  
Control Strategies ◽  
Mr Damper ◽  
Front Axle ◽  
Vehicle Body ◽  
Magnetorheological Dampers ◽  
The Road ◽  
Quarter Car Model ◽  
Car Model ◽  
Road Roughness ◽  
Suspension Model

The problem of vibration attenuation in a semiactive vehicle suspension is considered. The proposed solution is based on usage of the information about the road roughness coming from the sensor installed on the front axle of the vehicle. It does not need any preview sensor to measure the road roughness as other preview control strategies do. Here, the well-known Skyhook algorithm is used for control of the front magnetorheological (MR) damper. This algorithm is tuned to a quarter-car model of the front part of the vehicle. The rear MR damper is controlled by the FxLMS (Filtered-x LMS) taking advantage of the information about the motion of the front vehicle axle. The goal of this algorithm is to minimize pitch of the vehicle body. The strategy is applied for a four-degree-of-freedom (4-DOF) vehicle model equipped with magnetorheological dampers which were described using the Bouc-Wen model. The suspension model was subjected to the road-induced excitation in the form of a series of bumps within the frequency range 1.0–10 Hz. Different solutions are compared based on the transmissibility function and simulation results show the usefulness of the proposed solution.

Passive Suspension Optimization Using Teaching Learning Based Optimization and Genetic Algorithm Considering Variable Speed Over a Bump

2014 ◽  
Author(s):  
Bhargav Gadhvi ◽  
Vimal Savsani
Keyword(s):  
Genetic Algorithm ◽  
Ride Comfort ◽  
Optimization Techniques ◽  
Passive Suspension ◽  
The Road ◽  
Quarter Car Model ◽  
Teaching Learning Based Optimization ◽  
Quarter Car ◽  
Vehicle Suspension System ◽  
Teaching Learning

The main objectives of a vehicle suspension system are to isolate the road excitations to reach the sprung mass of the vehicle and proper road holding. This paper proposes a solution to optimize a quarter car linear passive suspension parameters while passing over a bump with variable speeds to improve the ride comfort and road holding. The Teaching-learning based optimization algorithm (TLBO) is used to solve the problem and results are compared to those obtained by Genetic algorithm (GA) technique. The quarter car model presented is simulated in time domain subjected to a Cosine speed bump considering the variable speeds of the vehicle over it. Results show sprung mass acceleration, and tire displacement are reduced by 26.03%, and 23.7% respectively by using TLBO and 22.3%, and 18.52% respectively by using GA, conforming the capabilities of the optimization techniques.

The Influence of Road Bumps Characteristics on the Chaotic Vibration of a Nonlinear Full-Vehicle Model with Driver

2016 ◽  
Vol 26 (09) ◽  
pp. 1650151 ◽  
Author(s):  
J. Fakhraei ◽  
H. M. Khanlo ◽  
M. Ghayour ◽  
Kh. Faramarzi
Keyword(s):  
Nonlinear Vibration ◽  
Ride Comfort ◽  
Chaotic Behavior ◽  
Speed Control ◽  
Vehicle Body ◽  
The Road ◽  
Chaotic Vibrations ◽  
Vehicle System ◽  
Road Speed ◽  
The Relationship

In this paper, the chaotic behavior of a ground vehicle system with driver subjected to road disturbances is studied and the relationship between the nonlinear vibration of the vehicle and ride comfort is evaluated. The vehicle system is modeled as fully nonlinear with seven degrees of freedom and an additional degree of freedom for driver (8-DOF). The excitation force is the road irregularities that are assumed as road speed control bumps. The sinusoidal, consecutive half-sine and dented-rectangular waveforms are considered to simulate the road speed control bumps. The nonlinearities of the system are due to the nonlinear springs and dampers that are used in the suspension system and tires. The governing differential equations are extracted under Newton–Euler laws and solved via numerical methods. The chaotic behaviors were studied in more detail with special techniques such as bifurcation diagrams, phase plane portrait, Poincaré map and Lyapunov exponents. The ride comfort was evaluated as the RMS value of the vertical displacement of the vehicle body and driver. Firstly, the effect of amplitude (height) and frequency (vehicle’s speed) of these speed control bumps on chaotic vibrations of vehicle are studied. The obtained results show that various forms of vibrations, such as periodic, subharmonic and chaotic vibrations, can be detected in the system behavior with the change of the height and frequency of speed control bumps and present different types of strange attractors in the vehicle with and without driver. Then, the influence of nonlinear vibration on ride comfort and the relationship between chaotic vibrations of the vehicle and driving comfort are investigated. The results of analyzing the RMS diagrams reveal that the chaotic behaviors can directly affect the driving comfort and lead to the driver’s comfort being reduced. The obtained results can be used in the design of vehicle and road bumps pavement.

Improvement of Ride Comfort with Active Suspension System Using Preview Control Law

1995 ◽  
Vol 7 (4) ◽  
pp. 307-311
Author(s):  
Hideo Tobata ◽  
◽  
Takeshi Kimura ◽  
Yohsuke Akatsu
Keyword(s):  
Ride Comfort ◽  
Vertical Motion ◽  
Active Suspension ◽  
Road Surface ◽  
Vehicle Body ◽  
Vertical Acceleration ◽  
Control Force ◽  
Preview Control ◽  
Rear Suspension ◽  
The Road

It is known that the ride comfort of a vehicle equipped with active suspension can be further improved if a priori information about the road surface, i.e., preview control, is used. This paper discusses the application of preview control to the rear wheels of a vehicle with active suspension. Information about the front wheels' vertical motion is used to estimate the vertical travel of the rear wheels. Vibration transmitted from the road surface to the vehicle body through the rear suspension can be estimated from the vertical motion of the wheels. Thus, the control force that should be generated by the rear suspension actuators can be obtained. Simulation results reveal that preview control provides an accurate estimate of road force inputs, enabling the vertical acceleration of the vehicle body to be reduced for further improvement in ride comfort. The results of vehicle driving tests also confirm that the preview-control force serves to reduce the vertical acceleration of the vehicle body. Cooperation between preview control and a skyhook damper is also discussed and shown to be effective in reducing vehicle body vibration.

Ride Comfort Optimisation of Passenger Car Passive Suspension Systems Using ADAMS/ Insight

2013 ◽  
Vol 395-396 ◽  
pp. 1142-1145 ◽  
Author(s):  
Ai Hua Tang
Keyword(s):  
Multibody Dynamics ◽  
Ride Comfort ◽  
Optimal Designs ◽  
Test Rig ◽  
Passenger Cars ◽  
Passenger Car ◽  
Passive Suspension ◽  
The Road ◽  
Suspension Systems ◽  
Iso 2631

The arising health problems of ride comfort of passenger cars point out that a lot of effort still has to be put into the design of passive suspension systems.The comfort problem originates from the vibrations transmitted to the driver and passengers caused by the unevenness of the road. This paper reports on an investigation to determine the spring and damper settings that will ensure optimal ride comfort of a passenger car at different speeds. D-optimal designs are developed via multibody dynamics software (ADAMS/Insight) with a model. Evaluation of the comfort improvement was done using an objective function according to the international organisation for standardisation (ISO)2631(1997). The optimised passive suspensions equipped in a passenger car were tested on a test rig in ADAMS/Car. The results show that the vibration levels can be reduced by 47%, generating a drastic comfort improvement.

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