Minimal Control Synthesis-Skyhook Mixed Control for Magneto-Rheological Semi-Active Suspension

2014 ◽  
Vol 1044-1045 ◽  
pp. 811-817
Author(s):  
Jin Qiu Zhang ◽  
Da Shan Huang ◽  
Zhi Zhao Peng ◽  
Guang Lei Zhang

Standard skyhook control algorithm is inefficient in controlling of the parameter-varying magneto-rheological semi-active suspension system. Based on model reference adaptive control theory, a minimal control synthesis-skyhook (MCS-SH) mixed control algorithm was designed. Ideal skyhook control was taken as the reference model; the feedback control law of MCS algorithm was improved based on the feature of magneto-rheological damper (MRD). The results illustrate that the sprung mass acceleration and suspension deflection are decreased through MCS-SH algorithm, the ride comfort of vehicles can be improved significantly, and the MCS-SH algorithm can adapt to the variation of suspension parameters.

Author(s):  
Ruochen Wang ◽  
Fupeng Sheng ◽  
Renkai Ding ◽  
Xiangpeng Meng ◽  
Zeyun Sun

This paper presents a vehicle attitude compensation algorithm based on state observer for vehicle semi-active suspension system equipped with four magneto-rheological dampers (MR dampers). The proposed algorithm including magneto-rheological damper control algorithm, attitude compensation control algorithm, and design method of state observer is to effectively improve ride comfort and control vehicle body attitude. First, the actual equivalent damping of magneto-rheological damper is introduced into state observer, and the parameter matrix of suspension system is updated in real time via precise discretization method to enhance the estimation accuracy of state observer. Then, the velocity signal estimated by state observer is employed as the evidence to realize attitude compensation control for vehicle body. Finally, relevant co-simulations and hardware-in-the-loop test are conducted to verify the validity of the proposed control algorithm. Results of simulations and tests demonstrate that the application of the control algorithm proposed in this paper can significantly improve ride comfort of magneto-rheological suspension and optimize vehicle body attitude.


Author(s):  
Madhavan Sudakar ◽  
Siddharth Sridhar ◽  
Manish Kumar

Abstract Proportional-Derivative (PD) controllers are commonly used in quadrotors due to their simple structure. Tuning of the gains of the PD controller is often cumbersome due to strong coupling of the dynamics between three linear and three angular degrees of freedom. This paper presents a novel method of auto adjusting the proportional and derivative gains of the quadrotor without the use of any stable reference model (unlike model reference adaptive control). The gains are automatically adjusted throughout the flight based on just the state errors. Lyapunov stability analysis and adaptive gain law is used to formulate the control algorithm to achieve way point navigation. It is shown that our proposed controller achieves effective way point navigation even when started off from random gain values.


2012 ◽  
Vol 479-481 ◽  
pp. 1355-1360
Author(s):  
Jian Guo Chen ◽  
Jun Sheng Cheng ◽  
Yong Hong Nie

Vehicle suspension is a MIMO coupling nonlinear system; its vibration couples that of the tires. When magneto-rheological dampers are adopted to attenuate vibration of the sprung mass, the damping forces of the dampers need to be distributed. For the suspension without decoupling, the vibration attenuation is difficult to be controlled precisely. In order to attenuate the vibration of the vehicle effectively, a nonlinear full vehicle semi-active suspension model is proposed. Considering the realization of the control of magneto-rheological dampers, a hysteretic polynomial damper model is adopted. A differential geometry approach is used to decouple the nonlinear suspension system, so that the wheels and sprung mass become independent linear subsystems and independent to each other. A control rule of vibration attenuation is designed, by which the control current applied to the magneto-rheological damper is calculated, and used for the decoupled suspension system. The simulations show that the acceleration of the sprung mass is attenuated greatly, which indicates that the control algorithm is effective and the hysteretic polynomial damper model is practicable.


Author(s):  
Amit Shukla ◽  
Jeong Hoi Koo

Nonlinear active suspension systems are very popular in the automotive applications. They include nonlinear stiffness and nonlinear damping elements. One of the types of damping element is a magneto-rheological fluid based damper which is receiving increased attention in the applications to the automotive suspension systems. Latest trends in suspension systems also include electronically controlled systems which provide advanced system performance and integration with various processes to improve vehicle ride comfort, handling and stability. A control bifurcation of a nonlinear system typically occurs when its linear approximation loses stabilizability. These control bifurcations are different from the classical bifurcation where qualitative stability of the equilibrium point changes. Any nonlinear control system can also exhibit control bifurcations. In this paper, control bifurcations of the nonlinear active suspension system, modeled as a two degree of freedom system, are analyzed. It is shown that the system looses stability via Hopf bifurcation. Parametric control bifurcation analysis is conducted and results presented to highlight the significance of the design of control system for nonlinear active suspension system. A framework for the design of feedback using the parametric analysis for the control bifurcations is proposed and illustrated for the nonlinear active suspension system.


Author(s):  
S¸ahin Yıldırım ◽  
I˙kbal Eski

This paper investigates a new robust model based neural controller for active suspension system’s vibrations via feedback control approach. The proposed model reference adaptive control system consists of a neural controller, a robust feedback controller, a third-order linear reference model and dynamics of active suspension system. The simulation examples with various standard input signals are included to demonstrate the effectiveness of the proposed control method and show significant improvement over the existing PID controller method. The robustness of the proposed neural controller is also analyzed with white noise disturbances on the suspension system. It is shown that the control system is robustly stable for all road disturbances. Finally, this kind of control approach could be employed in real time vehicle applications.


2016 ◽  
Vol 138 (4) ◽  
Author(s):  
Michael Z. Q. Chen ◽  
Yinlong Hu ◽  
Chanying Li ◽  
Guanrong Chen

This paper investigates the application of semi-active inerter in semi-active suspension. A semi-active inerter is defined as an inerter whose inertance can be adjusted within a finite bandwidth by online control actions. A force-tracking approach to designing semi-active suspension with a semi-active inerter and a semi-active damper is proposed in this paper. Two parts are required in the force-tracking strategy: a target active control law and a proper algorithm to adjust the inertance and the damping coefficient online to track the target active control law. The target active control law is derived based on the state-derivative feedback control methodology in the “reciprocal state-space” (RSS) framework, which has the advantage that it is straightforward to use the acceleration information in the controller design. The algorithm to adjust the inertance and the damping coefficient is to saturate the active control force between the maximal and the minimal achievable suspension forces of the semi-active suspension. Both a quarter-car model and a full-car model are considered in this paper. Simulation results demonstrate that the semi-active suspension with a semi-active inerter and a semi-active damper can track the target active control force much better than the conventional semi-active suspension (which only contains a semi-active damper) does. As a consequence, the overall performance in ride comfort, suspension deflection, and road holding is improved, which effectively demonstrates the necessity and the benefit of introducing semi-active inerter in vehicle suspension.


Author(s):  
Ardeshir Karami Mohammadi

A Variable Structure Model Reference Adaptive Controller (VS-MRAC) is proposed for Active control of vehicle suspension. One DOF quarter car model has been considered. The reference model is a one DOF vibrating system with skyhook damper. The structure of the switching functions is designed based on global exponential stability requirements, and shows perfect model following at a finite time. Sliding surfaces are independent of system parameters and therefore VS-MRAC is insensitive to system parameter variations. Simulation is presented for some road irregularities, and compares to active suspension with fixed structure MRAC, and passive suspension. VS-MRAC shows the best performance on ride and working space


Author(s):  
M. A. Ajaj ◽  
A. M. Sharaf ◽  
S. A. Hegazy ◽  
Y. H. Hossamel-deen

This paper presents a comprehensive investigation of automotive semi-active suspension control algorithms and compares their characteristics in terms of ride comfort and tire-road holding ability. Particular attention has been paid to the semi-active suspension systems fitted with a shock absorber of dual damping characteristics. Different mathematical models are presented to investigate the ride response considering both simplified and complex vehicle models. Numerical simulation has been carried out through the MATLAB/SIMULINK environment which aids the future development of controllable suspension systems to improve vehicle ride comfort. The results show a considerable improvement of the vehicle ride response using different schemes of semi-active suspension system in particular the modified groundhook control algorithm.


Author(s):  
Baek-soon Kwon ◽  
Daejun Kang ◽  
Kyongsu Yi

This article deals with the design of a partial preview active suspension control algorithm for the improvement of vehicle ride comfort. Generally, while preview-controlled active suspension systems have even greater potential than feedback-controlled systems, their main challenge is obtaining preview information of the road profile ahead. A critical drawback of the “look-ahead” sensors is an increased risk of incorrect detection influenced by water, snow, and other soft obstacles on the road. In this work, a feasible wheelbase preview suspension control algorithm without information about the road elevation has been developed based on a novel 3-degree-of-freedom full-car dynamic model which incorporates only the vehicle body dynamics. The main advantage of the employed vehicle model is that the system disturbance input vector consists of vertical wheel accelerations that can be measured easily. The measured acceleration information of the front wheels is used for predictive control of the rear suspension to stabilize the body motion. The suspension state estimator has also been designed to completely remove the effect of unknown road disturbance on the state estimation error. The estimation performance of an observer is verified via a simulation study and field tests. The performance of the proposed suspension controller is evaluated on a frequency domain and time domain via a simulation study. It is shown that the vehicle ride comfort can be improved more by the proposed wheelbase preview control approach than by the feedback approach.


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