scholarly journals Effects of Tyre Pressure on Vehicle Suspension Performance

Author(s):  
M. Hamed ◽  
B. Tesfa ◽  
F. Gu ◽  
A.D. Ball

Incorrect inflation pressures in tyres affects the vehicle handling, passenger comfort and braking conditions in addition to causing a reduction in fuel efficiency and tyre life. To address this problem, mathematical models have been produced and an experimental validation has been carried out. The models were developed with 7-DOF, for a full car system, using MATLAB programs. In the simulation study, the suspension faults have been considered by running the models with a range of inflation pressures at four conditions i.e. at standard pressure (2.3bar) and 1.5bar on the passenger wheel, driver wheel and front wheels. In each case, an analysis was carried out on the performances of the suspension in terms of ride comfort, road handling and stability of the vehicle followed by the presentation of the results obtained. In addition, the influence of parameter variations on transfer functions as a fault detection of suspension has been introduced. This approach has been used when detecting faults of vehicle tyres being under-inflated 35% and also to detect other suspension faults in the future.

Author(s):  
Peng Li ◽  
Lei Zuo

Conventional vehicle suspensions suppress vehicle vibrations by dissipating the vibration energy into unrecyclable heat with hydraulic dampers. This can be a considerable amount of energy which is worthy of attention for energy recovery. Electromagnetic regenerative dampers, or shock absorbers, are proposed to harvest this dissipated energy and to improve the fuel efficiency. The suspension dynamics with these regenerative dampers can be significantly different from the suspension dynamics with conventional dampers. First, different from conventional hydraulic dampers, the electromagnetic regenerative dampers have a significantly higher inertia, which is introduced by the electromagnetic generator. This has an important impact on the suspension dynamics. Second, the damping coefficient of electromagnetic dampers is related to the electric load connected to the output of the generator and can be controllable. Although various concepts have been proposed, the influences of these types of regenerative damper on the vehicle dynamics have not yet been thoroughly investigated. This paper models two types of rotational electromagnetic regenerative damper, with and without a mechanical motion rectifier, and analyzes their influences on the vehicle suspension performance in comparison with those of the conventional damper. The modeling in this paper also considers the case when the tires lose contact with the ground. Simulations were carried out with step road profile excitations and road profile excitations defined by the International Standardization Organization in order to evaluate the influences of the equivalent inertia mass and the equivalent damping coefficient. The results showed that, with an optimized equivalent inertia mass, both types of electromagnetic damper can achieve better ride comfort performances than a constant damper does. In addition, the mechanical motion rectifier mechanism can significantly improve the ride comfort and the road-handling performance of electromagnetic regenerative dampers by reducing the negative effect of the amplified generator inertia. In addition, the energy-harvesting potential of the presented dampers under road profile excitations defined by the International Standardization Organization was evaluated.


Author(s):  
Marian Sikora ◽  
Janusz Gołdasz

The aim of this work is to provide an insight into the rattle noise phenomena occurring in double-tube (twin-tube) vehicle suspension dampers. In the dampers the particular phenomenon results from interactions between the valve(s) and the fluid passing through them. The rattling noise phenomena is known to degrade the vehicle passenger’s perception of ride comfort as well as to influence the performance of the dampers at low and medium speeds in particular. In the paper the authors reveal the results of a DOE (Design of Experiment) study involving several design parameters known to affect rattling occurrence. By running a series of purpose-designed tests the authors investigate not only the contribution of each particular parameter but the interactions between them. The results are presented in the form of pareto charts, main effect plots as well as interaction plots. It is expected the outcome of the analysis will aid in a better comprehension of the phenomena as well the definition of valve configurations to minimize their performance degradation.


2015 ◽  
Vol 1115 ◽  
pp. 440-445 ◽  
Author(s):  
Musa Mohammed Bello ◽  
Amir Akramin Shafie ◽  
Raisuddin Khan

The main purpose of vehicle suspension system is to isolate the vehicle main body from any road geometrical irregularity in order to improve the passengers ride comfort and to maintain good handling stability. The present work aim at designing a control system for an active suspension system to be applied in today’s automotive industries. The design implementation involves construction of a state space model for quarter car with two degree of freedom and a development of full state-feedback controller. The performance of the active suspension system was assessed by comparing it response with that of the passive suspension system. Simulation using Matlab/Simulink environment shows that, even at resonant frequency the active suspension system produces a good dynamic response and a better ride comfort when compared to the passive suspension system.


Energies ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 5560
Author(s):  
Jarosław Konieczny ◽  
Marek Sibielak ◽  
Waldemar Rączka

In the paper authors consider the active suspension of the wheeled vehicle. The proposed controller consists of a sliding mode controller used to roll reduction and linear regulators with quadratic performance index (LQRs) for struts control was shown. The energy consumption optimization was taken into account at the stage of strut controllers synthesis. The studied system is half of the active vehicle suspension using hydraulic actuators to increase the ride comfort and keeping safety. Instead of installing additional actuators in the form of active anti-roll bars, it has been decided to expand the active suspension control algorithm by adding extra functionality that accounts for the roll. The suggested algorithm synthesis method is based on the object decomposition into two subsystems whose controllers can be synthesized separately. Individual suspension struts are controlled by actuators that use the controllers whose parameters have been calculated with the LQR method. The mathematical model of the actuator applied in the work takes into account its nonlinear nature and the dynamics of the servovalve. The simulation tests of the built active suspension control system have been performed. In the proposed solution, the vertical displacements caused by uneven road surface are reduced by controllers related directly to suspension strut actuators.


Author(s):  
Hemanth Porumamilla ◽  
Atul G. Kelkar

This study presents an H∞-based robust control design for an active automobile suspension system and compares its performance with a previously designed robust LQG controller and a well tuned PI controller from contemporary literature. The robustness of the controller designs is assessed by performing μ analysis of the closed loop system. The H∞ problem is formulated as a stacked nominal performance problem. The weighting functions on complementary sensitivity, sensitivity, and controller transfer functions are chosen to obtain desirable trade-off in performance and robustness. The main objective of the controller design is to provide ride comfort for passengers. The controller design presented in this paper is shown to provide robust stability as well as desirable robust performance which is an improvement over the previously designed robust LQG controller and a PI controller chosen from contemporary literature.


Author(s):  
Olugbenga M. Anubi ◽  
Carl D. Crane

A new variable stiffness suspension system based on a recent variable stiffness mechanism is proposed. The overall system is composed of the traditional passive suspension system augmented with a variable stiffness mechanism. The main idea is to improve suspension performance by varying stiffness in response to road disturbance. The system is analyzed using a quarter car model. The passive case shows much better performance in ride comfort over the tradition counterpart. Analysis of the invariant equation shows that the car body acceleration transfer function magnitude can be reduced at both the tire-hop and rattle space frequencies using the lever displacement transfer function thereby resulting in a better performance over the traditional passive suspension system. An H∞ controller is designed to correct for the performance degradation in the rattle space thereby providing the best trade-off between the ride comfort, suspension deflection and road holding.


2013 ◽  
Vol 456 ◽  
pp. 189-192 ◽  
Author(s):  
Xiao Zhen Qu ◽  
Guang Quan Hou ◽  
Hao Liu ◽  
Hui He

One new negative stiffness suspension is introduced in this paper. The vehicle with negative stiffness suspension has good ride comfort and handling stability. The natural frequency of system could be reduced in vertical direction by applying negative stiffness suspension. The vehicle model with negative stiffness suspension or not is built in ADAMS. The comparison of simulation results show that the vehicle with negative stiffness suspension could reduce the natural frequency of system and vibration transmissibility, and also improve the vehicle ride comfort and vehicle handling stability.


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