Vehicle attitude compensation control of magneto-rheological semi-active suspension based on state observer

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):  
Hao Chen ◽  
Mingde Gong ◽  
Dingxuan Zhao ◽  
Jianxu Zhu

This paper proposes an attitude control strategy based on road level for heavy rescue vehicles. The strategy aims to address the problem of poor ride comfort and stability of heavy rescue vehicles in complex road conditions. Firstly, with the pressure of the suspension hydraulic cylinder chamber without a piston rod as the parameter, Takagi–Sugeno fuzzy controller classification and adaptive network-based fuzzy inference system controller classification are used to recognise the road level. Secondly, particle swarm optimisation is adopted to obtain the optimal parameters of the active suspension system of vehicle body attitude control under different road levels. Lastly, the parameters of the active suspension system are selected in accordance with the road level recognised in the driving process to improve the adaptive adjustment capability of the active suspension system at different road levels. Test results show that the root mean square values of vertical acceleration, pitch angle and roll angle of the vehicle body are reduced by 59.9%, 76.2% and 68.4%, respectively. This reduction improves the ride comfort and stability of heavy rescue vehicles in complex road conditions.


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.


2014 ◽  
Vol 668-669 ◽  
pp. 474-477
Author(s):  
Qi Hua Ma ◽  
Jing Luo ◽  
Chun Yan Zhang

The suspension system is one of the most important parts of the automobile. The suspension system has an important influence on the ride comfort and maneuverable stability of the automobile. As structure parameters of traditional passive suspension cannot adaptively change with external conditions, the improvement of dynamic performance is difficult. Tow-DOF and four-DOF suspension of vehicle model is set up in this paper. Under random profiled road input simulated by using Runge-Kutta method, the control laws of fuzzy controller are adjusted by using different weight coefficients and use Matlab software to simulate the performances. Then, the results are compared and the performances are analyzed between passive suspension and semi-active suspension. The simulation results show the semi-active suspension is more effective for decreasing the vibration of vehicle body than the passive suspension, and designed fuzzy controller is effective for controlling the active controller of the semi-active suspension.


2013 ◽  
Vol 340 ◽  
pp. 631-635
Author(s):  
Yong Fa Qin ◽  
Jie Hua ◽  
Long Wei Geng

Vehicles with active suspension systems become more ride comfort and maneuverable stability, many types of active suspensions have been applied to passenger vehicles, but one of the shortcomings of an active susupension system is that the additional control power consumption is needed. The core issues of designing an active suspension system are to minimiaze vibration magnitute and control energy comsuption of the active suspension system. A new mathematic model for an active suspension system is established based on vehicle dynamics and modern control theory. An optimal control law is constructed through solving the Riccati equation, and then the transfer function is deduced to describe the relationship between the vetical velosity of the road roughness and the output of suspension system. Three typical parameters of vehicle ride comfort are researched, such as vertical acceleration of vehicle body, dynamic deflection of suspension system and dynamic deformation of tires. A case of a quarter vehicle model is studied by simulation to show that the proposed method of modeling and designing optimal controller are suitable to develop active suspension systems.


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.


Author(s):  
Beibei Liu ◽  
Lin Xu ◽  
Zhen Zhao ◽  
Mohamed A. A. Abdelkareem ◽  
Junyi Zou ◽  
...  

Active suspension can adapt itself to the rigidity and the damping characteristics based on the vehicle dynamic state and the road condition, making the suspension in the best state of shock absorbing, which can increase the handling stability, the ride comfort and the passing ability of vehicles. As for strikingly rugged roads like off-road conditions, the traditional active suspension can hardly balance the contradiction between the wheel adhesion and the vertical accelerated speed of the body. In this paper, an active suspension in which the position of the vehicle body can be adjusted is proposed. In the proposed suspension, a series of electric cylinders are installed, which can actively adjust the position between the vehicle body and the suspension in order to achieve the purpose of controlling the relative body-wheels position. In this manner, AMESim is used to set up three suspension designs which include suspension supporter adaptation equipment with different locations in the system. Through simulation analysis, the paper has explored the feasibility of the vehicle attitude control of the three suspension designs under off-road conditions. The results proved that the active suspension system with adjustable body position can restrain the body roll or pitch efficiently in which this technology can be applied to the body attitude control when ORVs are at high speed.


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.


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