Multi-domain unified modeling and simulation of semi-active suspension in magnerorheological damper
In order to build high-precision and highefficient MR damper system model, a multi-domain unified modeling method was proposed. Firstly, based on the analysis of a MR damper semi-active suspension system model, various fields of MR, such as structure, magnetic field, control and mechanics, were studied to find the main influencing parameters. And then for the multi-domain coupling characteristics of MR damper, a multi-domain unified modeling of MR damper system was established based on Modelica/MWorks platform. By adjusting the main influencing parameters, the relationship diagrams between the parameters and the performances were obtained. Finally, some performance results were compared with the traditional method used Matlab/simulink modeling and the method proposed. The results show that the model based on Modelica can preferably reflect the complex relationship between the MR damper coupling among the parameters within the system, and can get a better simulation result.
Vibration control for a half-car model with adaptation of the magnetorheological damper model
The paper presents vehicle vibration control using magnetorheological (MR) dampers. Typical algorithms to control this semi-active suspension need the inverse model of the damper. Modelling of the damper is not a trivial task because of its highly non-linear behaviour. Also, effectiveness of damping vibrations caused by the road depends significantly on the quality of the model. Therefore, an identification algorithm based on iterative estimation of immeasurable signals is proposed. Two control algorithms are tested - Skyhook and FxLMS (Filtered-x LMS). Simulation experiments for a half-car model excited by road bumps show usefulness of this approach. It was also observed that the FxLMS is not very sensitive to modelling errors as it includes an internal mechanism of adaptation. On the other hand, the Skyhook fails if the model is inaccurate, so it should be used together with the identification of the MR damper.
Analytical and experimental studies on active suspension system of light passenger vehicle to improve ride comfort
This paper describes the development of activesuspension system of light passenger vehicle to improveride comfort of the passengers using PID (Proportional –Integral - Derivative) controller. The system is subjected tobumpy road and its performance is assessed and comparedwith a passive suspension system. Tuning of the controllerparameters is also illustrated. Experimental verification ofanalytical results is carried out. It is found that ride comfortis improved by 78.03%, suspension travel has been reducedby 71.05% and road holding ability is improved by60% with active suspension system when compared withpassive suspension system. Therefore it is concluded thatactive suspension system with PID controller is superior topassive suspension system.