scholarly journals Optimal Control of an 8-DOF Vehicle Active Suspension System Using Kalman Observer

2008 ◽  
Vol 15 (5) ◽  
pp. 493-503 ◽  
Author(s):  
S. Hossein Sadati ◽  
Salar Malekzadeh ◽  
Masood Ghasemi

In this paper, an 8-DOF model including driver seat dynamics, subjected to random road disturbances is used in order to investigate the advantage of active over conventional passive suspension system. Force actuators are mounted parallel to the body suspensions and the driver seat suspension. An optimal control approach is taken in the active suspension used in the vehicle. The performance index for the optimal control design is a quantification of both ride comfort and road handling. To simulate the real road profile condition, stochastic inputs are applied. Due to practical limitations, not all the states of the system required for the state-feedback controller are measurable, and hence must be estimated with an observer. In this paper, to have the best estimation, an optimal Kalman observer is used. The simulation results indicate that an optimal observer-based controller causes both excellent ride comfort and road handling characteristics.

2019 ◽  
Vol 11 (2) ◽  
pp. 55
Author(s):  
Nur Uddin

The optimal control design of the ground-vehicle active suspension system is presented. The active suspension system is to improve the vehicle ride comfort by isolating vibrations induced by the road profile and vehicle velocity. The vehicle suspension system is approached by a quarter car model. Dynamic equations of the system are derived by applying Newton’s second law. The control law of the active suspension system is designed using linear quadratic regulator (LQR) method. Performance evaluation is done by benchmarking the active suspension system to a passive suspension system. Both suspension systems are simulated in computer. The simulation results show that the active suspension system significantly improves the vehicle ride comfort of the passive suspension system by reducing 50.37% RMS of vertical displacement, 45.29% RMS of vertical velocity, and 1.77% RMS of vertical acceleration.


2013 ◽  
Vol 765-767 ◽  
pp. 382-386
Author(s):  
Jian Kun Peng ◽  
Hong Wen He ◽  
Bing Lu

A 7-DOFs vehicle dynamics model which includes active suspension system (ASS) is established, and a LQR controller for active suspension system was designed based on optimal control theory. The simulation models for active suspension system and passive suspension system were built, and a simulation experiment was carried out with MATLAB/Simulink Software. The simulation results show that the optimal control of active suspension system can reduce vertical, roll and pitch accelerations of sprung mass, and the vehicle ride comfort and handling stability were improved effectively.


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.


Author(s):  
Yan-Jun Liang ◽  
You-Jun Lu ◽  
De-Xin Gao ◽  
Zhong-Sheng Wang

AbstractTechnique of approximate optimal vibration control and simulation for vehicle active suspension systems are developed. Considered the nonlinear damping of springs, mechanical model and a nonlinear dynamic system for a class of tracked vehicle suspension vibration control are established and the corresponding system of state space form is described. To prolong the working life of suspension system and improve ride comfort, based on the active suspension vibration control devices and using optimal control approach, an approximate optimal vibration controller is designed, and an algorithm is presented for the vibration controller. Numerical simulation results illustrate the effectiveness of the proposed technique.


Author(s):  
Ahmad A. Fayed ◽  
Mohamed B. Trabia ◽  
Mohamed M. ElMadany

Optimal control schemes are usually employed to minimize different performance criteria of active suspension system of a vehicle such as, ride comfort and road safety. These factors are usually combined into a single quantity using proper weighting parameters that depend on the designer’s preferences. Generally, the selection of these weighting parameters is based on trial and error, which can be a time-consuming and computationally-intensive process. This paper proposes the use of an approach based on nested optimization loops to automate the selection process of these weighting parameters. The objective of the inner optimization loop is to minimize of the quadratic performance index associated with the original active suspension problem while the objective of the outer optimization loop is to minimize driver’s acceleration, for ride comfort, while maintaining both tire deflection and suspension deflection within acceptable limits. The design variables are the weighting parameters associated with the quadratic performance index used in the optimal control of active suspension. A modified form of Hooke-Jeeves algorithm is used to handle this problem while the penalty function method is used to handle the constraints. Simulation results show that this approach can improve the design process for active suspension of vehicles.


2015 ◽  
Vol 11 (2) ◽  
pp. 151-158 ◽  
Author(s):  
Wissam Al-Mutar ◽  
Turki Abdalla

The objective of this paper is to design an efficient control scheme for car suspension system. The purpose of suspension system in vehicles is to get more comfortable riding and good handling with road vibrations. A nonlinear hydraulic actuator is connected to passive suspension system in parallel with damper. The Particles Swarm Optimization is used to tune a PID controller for active suspension system. The designed controller is applied for quarter car suspension system and result is compared with passive suspension system model and input road profile. Simulation results show good performance for the designed controller.


2021 ◽  
Vol 2129 (1) ◽  
pp. 012014
Author(s):  
M H Ab Talib ◽  
I Z Mat Darus ◽  
H M Yatim ◽  
M S Hadi ◽  
N M R Shaharuddin ◽  
...  

Abstract The semi-active suspension (SAS) system is a partial suspension device used in the vehicle system to improve the ride comfort and road handling. Due to the high non-linearity of the road profile disturbances plus uncertainties derived from vehicle dynamics, a conventional Skyhook controller is not deemed enough for the vehicle system to improve the performance. A major problem of the implementation of the controller is to optimize a proper parameter as this is an important element in demanding a good controller response. An advanced Firefly Algorithm (AFA) integrated with the modified skyhook (MSky) is proposed to enhance the robustness of the system and thus able to improve the vehicle ride comfort. In this paper, the controller scheme to be known as MSky-AFA was validated via MATLAB simulation environment. A different optimizer based on the original firefly algorithm (FA) is also studied in order to compute the parameter of the MSky controller. This control scheme to be known as MSky-FA was evaluated and compared to the proposed MSky-AFA as well as the passive suspension control. The results clearly exhibit more superior and better response of the MSky-AFA in reducing the body acceleration and displacement amplitude in comparison to the MSky-FA and passive counterparts for a sinusoidal road profile condition.


2013 ◽  
Vol 313-314 ◽  
pp. 382-386
Author(s):  
Wen Kui Lan ◽  
Er Dong Ni

A fuzzy-PID controller is developed and applied to the active suspension system for the ride comfort enhancement of a half-vehicle model. A four degree-of-freedom vehicle model with active suspension system is proposed, which focused on the passenger’s ride comfort performance, and a fuzzy-PID controller is developed by incorporating the fuzzy logic control mechanism into the modifications of the PID structure. The performance of the proposed controller has been verified by comparing it with passive control method in MATLAB/Simulink. The simulation results indicate that the developed fuzzy-PID controller enhances the ride comfort performance of the vehicle active suspension system by reducing the body acceleration and pitch angle significantly.


Author(s):  
Alireza Rezaee ◽  
Mazyar Pajohesh

In this paper, fuzzy logic is used to control active suspension of one-quarter car model. The main role of a car suspension system is to improve the ride comfort and to better the handling property. It usually consists of a spring and a damper to improve the properties of suspension system. The fuzzy logic method is one of the most active research and developments areas on artificial and intelligence at the present time, particularly in the automobile industry. One quarter of car if modeled by springs, masses, dampers and force actuator and the state space equations are derived by lagrangian method. The ride comfort is improved by means of the reduction of the body acceleration caused by the car body when road disturbance from uneven road surfaces, pavement point etc. act on the tires of running car. Here, a logic fuzzy controller is designed in which, the number of rule bases are reduced in comparison with some traditional one which have been introduced in other papers. At the end, a comparison of active suspension fuzzy control and traditional passive suspension is shown using MATLAB simulations. Results show that, active suspension improves the ride comfort by reducing acceleration, compared with the performance of passive suspension.


Author(s):  
N.M. Ghazaly ◽  
A.S Ahmed ◽  
A.S Ali ◽  
G.T Abd El- Jaber

In recent years, the use of active control mechanisms in active suspension systems has attracted considerable attention. The main objective of this research is to develop a mathematical model of an active suspension system that is subjected to excitation from different road profiles and control it using H∞ technique for a quarter car model to improve the ride comfort and road handling. Comparison between passive and active suspension systems is performed using step, sinusoidal and random road profiles. The performance of the H∞ controller is compared with the passive suspension system. It is found that the car body acceleration, suspension deflection and tyre deflection using active suspension system with H∞ technique is better than the passive suspension system.


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