scholarly journals Design of a modified linear quadratic regulator for vibration control of suspension systems

2011 ◽  
Vol 2 (1) ◽  
pp. 25-31
Author(s):  
Ş. Yildirim ◽  
M. Kalkat ◽  
İ. Uzmay ◽  
G. Husi

Abstract This paper is concerned with the construction of a prototype active vehicle suspension system for a one-wheel car model by using a modified Linear Quadric Regulator (LQR). The experimental system is approximately described by a non-linear system with two degrees of freedom subject to excitation from a road profile. The active control at the suspension location is designed by using feedback constant gain controller structure. The experimental results show that the active suspension system with LQR more improves the control performance than standard PID controller. On the other hand, the results improved that the modified LQR has superior performance for controlling suspension systems in real time.

2010 ◽  
Vol 1 (1-2) ◽  
pp. 55-60 ◽  
Author(s):  
Y. Şahin ◽  
G. Husi

Abstract The army and the people use many types of vehicles for industrial applications and military applications. This paper is proposed a construction of a prototype active vehicle suspension system for a one-wheel car model by using a modified Linear Quadric Regulator (LQR). The experimental system is approximately described by non-linear system with two degrees of freedom subject to excitation from profile different road disturbance profile. The active control at the suspension location is designed by using feedback constant gain controller structure. Furthermore, the experimental results show that the active suspension system with LQR more improves the control performance than standard PID controller. On the other hand, the results improved that the modified LQR has superior performance for controlling suspension systems in real time.


2020 ◽  
Vol 10 (22) ◽  
pp. 8060
Author(s):  
Ahmad Fares ◽  
Ahmad Bani Younes

In this paper, a controller learns to adaptively control an active suspension system using reinforcement learning without prior knowledge of the environment. The Temporal Difference (TD) advantage actor critic algorithm is used with the appropriate reward function. The actor produces the actions, and the critic criticizes the actions taken based on the new state of the system. During the training process, a simple and uniform road profile is used while maintaining constant system parameters. The controller is tested using two road profiles: the first one is similar to the one used during the training, while the other one is bumpy with an extended range. The performance of the controller is compared with the Linear Quadratic Regulator (LQR) and optimum Proportional-Integral-Derivative (PID), and the adaptiveness is tested by estimating some of the system’s parameters using the Recursive Least Squares method (RLS). The results show that the controller outperforms the LQR in terms of the lower overshoot and the PID in terms of reducing the acceleration.


Author(s):  
O Kavianipour ◽  
M Montazeri-Gh ◽  
M Moazamizadeh

This paper deals with the two degrees of freedom response-type mechanism (2 DOF RTM) designed at Iran University Science and Technology. The applications of the 2 DOF RTM are to measure the longitudinal road profile and assess the vehicle suspension system. When the 2 DOF RTM is connected to a vehicle, it is able to measure the longitudinal road profile and it is capable of assessing the vehicle suspension system while it is perched upon the exciting device. The most important part of the 2 DOF RTM is its hub planned for decreasing the vehicle movement effects on the measurement. Moreover, this paper develops a novel procedure in order to convert the measured profile from the variable speed to the constant speed. To examine the 2 DOF RTM, a profile of a road is measured by the mechanism in the time-domain, and then the highly significant roughness indices such as power spectral density (PSD) of the road unevenness, international roughness index (IRI) and present serviceability index (PSI) are estimated using the measured profile.


2011 ◽  
Vol 141 ◽  
pp. 319-322
Author(s):  
Jun Zhong Xia ◽  
Zong Po Ma ◽  
Shu Min Li ◽  
Xiang Bi An

This paper focuses on the influence of various vehicle suspension systems on ride comfort. A vehicle model with eight degrees of freedom is introduced. With this model, various types of non-linear suspensions such as active and semi-active suspensions are investigated. From this investigation, we draw the conclusion that the active and semi-active suspensions models are beneficial for ride comfort.


Author(s):  
Ali Fellah Jahromi ◽  
A. Zabihollah

A novel semi-active control system for suspension systems of passenger car using Magnetorheological (MR) damper is introduced. The suspension system is considered as a massspring model with an eight-degrees-of-freedom, a passive damper and an active damper. The semi-active vibration control is designed to reduce the amplitude of automotive vibration caused by the alteration of road profile. The control mechanism is designed based on the optimal control algorithm, Linear Quadratic Regulator (LQR). In this system, the damping coefficient of the shock absorber changes actively trough inducing magnetic field. It is observed that utilizing the present control algorithm may significantly reduce the vibration response of the passenger car, thus, providing comfortable drive. The new developed suspension system may lead to design and manufacturing of passenger car in which the passenger may not feel the changes in road profile from highly bumpy to smooth profile.


Author(s):  
Jahangir Rastegar ◽  
Dake Feng

In recent studies, a new class of planar and spatial linkage mechanisms was presented in which for a continuous full rotation or continuous rocking motion of the input link, the output link undergoes two continuous rocking motions. Such linkage mechanisms were referred to as the “motion-doubling” linkage mechanisms. This class of mechanisms was also shown to generally have dynamics advantage over regular mechanisms designed to achieve similar gross output motions. In a recent study, the application of such motion-doubling linkage mechanisms to vehicle suspension system was investigated. In the present study, the performance of a vehicle using such a suspension system is compared to a suspension system regularly used in vehicles. For a typical set of vehicle and tire parameters, the parameters of both suspension systems are optimally determined with a commonly used objective function. The performance of the two systems in the presence of various input disturbances is then determined using computer simulation. It is shown that suspension systems constructed with motion-doubling linkage mechanisms can provide a significantly superior performance as compared to a commonly used suspension system.


Author(s):  
Mohammad Biglarbegian ◽  
William Melek ◽  
Farid Golnaraghi

Semi-active suspension systems allow for adjusting the vehicle shock damping and hence improved suspension performance can be achieved over passive methods. This paper presents the design of a novel fuzzy control structure to concurrently improve ride comfort and road handling of vehicles with semi-active suspension system. A full car model with seven degrees of freedom is adopted that includes the vertical, roll, and pitch motions as well as the vertical motions of each wheel. Four decentralized fuzzy controllers are developed and applied to each individual damper in the vehicle suspension system. Mamdani’s method is applied to infer the damping coefficient output from the fuzzy controller. To evaluate the performance of the proposed controller, numerical analyses were carried out on a real road bump. Moreover, results were compared with well-known and widely used controllers such as Skyhook. It is shown that the proposed fuzzy controller is capable of achieving enhanced ride comfort and road handling over other widely used control methods.


Author(s):  
Eungkil Lee ◽  
Tao Sun ◽  
Yuping He

This paper presents a parametric study of linear lateral stability of a car-trailer (CT) combination in order to examine the fidelity, complexity, and applicability for control algorithm development for CT systems. Using MATLAB software, a linear yaw-roll model with 5 degrees of freedom (DOF) is developed to represent the CT combination. In the case of linear stability analysis, a parametric study was carried out using eigenvalue analysis based on a linear yaw-roll CT model with varying parameters. Built upon the linear stability analysis, an active trailer differential braking (ATDB) controller was designed for the CT system using the linear quadratic regulator (LQR) technique. The simulation study presented in this paper shows the effectiveness of the proposed LQR control design and the influence of different trailer parameters.


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