Papers by Keyword: Active Suspension System

Abstract: 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.

Abstract: This paper presents an evaluation of ride comfort performance of a passenger vehicle when converted into an electric vehicle (EV). The evaluations were done using a validated 7 degrees of freedom of vehicle’s ride model. The developed vehicle’s ride model was used to predict the vehicle’s ride behaviours when subjected to random road profiles. The ride model of EV conversion was then integrated with the active suspension system in order to further improve the EV conversion’s ride comfort performance. It was found that the modifications of a normal passenger vehicle into an EV conversion do not affect vehicle’s ride comfort performance significantly, except the conversion changes only the magnitude of vehicle’s vertical displacement, pitch rate and pitch angle responses. However, the integration of an active suspension system in EV conversions ride model was improves the observed responses of EV conversion’s ride comfort performance by overall improvement of 65.7 percents.

Abstract: This paper presents an estimator for a nonlinear active suspension system considering the hydraulic actuator dynamics. PID controller is used to control the Active suspension system of nonlinear quarter car model. Extended Kalman filter is designed to estimate the states from the measurement model perturbed with noise. Simulation results demonstrate the effectiveness of the PID based active suspension system in reducing the vertical acceleration transmitted to the passengers thereby improving the ride comfort. Also the effectiveness of the Extended Kalman filter in estimating the actual vehicle states is demonstrated.

Abstract: A neuro-fuzzy control (NFC) system is developed to control the suspension system of vehicle due to its nonlinearity and parameter variations. A neural network (NN) is used to adjust the premise parameters and the consequent parameters in fuzzy logic control (FLC). Simulation results by using NFC are compared with those of the conventional PID controller and passive suspension system. Based on the simulation, it can be concluded that the neuro-fuzzy controller shows a good performance in both passenger comfort and vehicle handing in comparison to the conventional PID controller and passive suspension system.

Abstract: In this paper the digital controller design for vehicle suspension system, based on a half-car model using singular perturbed systems is considered. This strategy is based on the slow and fast subsystems controller design. The simulation results show them favorable performance of the controller and achieve fast and good response.

Abstract: In this paper the singular perturbation theory is used to design observer for estimation of state variables for proper control of half-car active suspension system. The liner quadric Gaussian (LQG) controller has been used to obtain feedback gains. The suspension system performance is optimized with respect to ride comfort, tire deflections and front and rear suspension travels. The simulation results show that the proposed approach is highly effective in evaluating the performance of an active suspension system.

Abstract: The main aim of suspension system is to isolate a vehicle body from road irregularities in order to maximize passenger ride comfort and retain continuous road wheel contact in order to provide road holding. 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. The paper describes also the model and controller used in the study and discusses the vehicle response results obtained from a range of road input simulations. In the conclusion, a comparison of active suspension fuzzy control and Proportional Integration derivative (PID) control is shown using MATLAB simulations.

Abstract: The content of this work is the presentation of the prototype of a new active suspension system with an active air spring. As being part of the Collaborative Research Unit SFB805 “Control of Uncertainties in Load-Carrying Structures in Mechanical Engineering”, founded by the Deutsche Forschungsgemeinschaft DFG, the presented active air suspension strut is the first result of the attempt to implement the following requirements to an active suspension system: Harshness and wear: Reduced coulomb friction, i.e. no dynamic seal. Plug and drive solution: Connected to the electrical power infrastructure of the vehicle. Vehicle and customer application by software and not by hardware adaption. These requirements were defined at the very beginning of the project to address uncertainties in the life cycle of the product and the market needs. The basic concept of the active air spring is the dynamic alteration of the so-called effective area. This effective area is the load carrying area A of a roller bellow and defined by A:=F/(p-pa). F denotes the resulting force of the strut, p the absolute gas pressure and pa the ambient pressure. The alteration of this effective area is realized by a mechanical power transmission, from a rotational movement to four radial translated piston segments. Due to the radial movement of the piston segments, the effective area A increases and so does finally the axial compression force F. The prototype presented in this paper serves as a demonstrator to proof the concept of the shiftable piston segments. This prototype is designed to gather information about the static and dynamic behavior of the roller bellows. Measurements show the feasibility of the concept and the interrelationship between the piston diameter and the resulting spring force.

Abstract: This paper describes the development of a controller design for the active control of suspension system, which improves the inherent tradeoff among ride comfort, suspension travel and road-holding ability. The developed design allows the suspension system to behave differently in different operating conditions, without compromising on road-holding ability. The effectiveness of this control method has been explained by data from time domains. Proportional-Integral-Derivative (PID) controller including hydraulic dynamics has been developed. The displacement of hydraulic actuator and spool valve is also considered. The Ziegler – Nichols tuning rules are used to determine proportional gain, reset rate and derivative time of PID controller. Simulink diagram of active suspension system is developed and analysed using MATLAB software. The investigations on the performance of the developed active suspension system are demonstrated through comparative simulations in this paper.