Semi-active suspension with semi-active inerter and semi-active damper

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 on-line control actions. A force-tracking approach to designing semi-active suspension with a semi-active inerter and a semi-active damper is proposed, where the target active control force derived by LQR control in the 'Reciprocal State-Space' (RSS) framework is tracked by controlling the semi-active damping coefficient and semi-active inertance. One of the advantages of the proposed method is that it is straightforward to use the acceleration information in the controller design. 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.preprin

Skyhook surface sliding mode control on semi-active vehicle suspension systems for ride comfort enhancement

A skyhook surface sliding mode control method was proposed and applied to the control on the semi-active vehicle suspension system for its ride comfort enhancement. A two degree of freedom dynamic model of a vehicle semi-active suspension system was given, which focused on the passenger’s ride comfort perform-ance. A simulation with the given initial conditions has been devised in MATLAB/SIMULINK. The simula-tion results were showing that there was an enhanced level of ride comfort for the vehicle semi-active sus-pension system with the skyhook surface sliding mode controller

Robust vehicle suspension system by converting active and passive control of a vehicle to semi-active control ystem analytically

This research article deals with a simplified translational model of an automotive suspension system which is constructed by considering the translation motion of one wheel of a car. Passive Vehicle Suspension System is converted into Semi Active Vehicle System. Major advantage achieved by this system is that it adjusts the damping of the suspension system without the application of any actuator by using MATLAB® simulations. The semi-active control is found to control the vibration of suspension system very well

Prototyping a new car semi-active suspension by variational feedback controller

New suspension systems electronically controlled are presented and mounted on board of a real car. The system consists of variable semi-active magneto-rheological dampers that are controlled through an electronic unit that is designed on the basis of a new optimal theoretical control, named VFC-Variational Feedback Controller. The system has been mounted on board of a BMW Series 1 car, and a set of experimental tests have been conducted in real driving conditions. The VFC reveals, because of its design strategy, to be able to enhance simultaneously both the comfort performance as well as the handling capability of the car. Preliminary comparisons with several industrially control methods adopted in the automotive field, among them skyhook and groundhook, show excellent results

Evaluation of a semi-active gravity gradient system. Volume II - Appendices

Evaluation of semi-active gravity gradient system - appendixe

Evaluation of a semi-active gravity gradient system. Volume I - Technical summary

Semi-active gravity gradient system for attitude control of earth oriented spacecraf

Delevolpment of semi active suspension system

The suspension of the car plays a very important role in the safety and the comfort of the vehicle and for absorbing the shock waves and give comfort for the driver and passenger. There are different classifications of suspension, which are passive, semi-active and active suspension. There is potential for improve the model of the shock absorber, by developing electronically controllable semi active shock absorber. However, semi-active absorber been chosen for modification due better efficiency and providing different characteristic of damping ratio when compares to the passive shock absorber and low cost when compare with active shock absorber. Therefore, a controller was developed to be attached with the absorber to the control the degree of softness and hardness. The level of softness and hardness of shock absorbers play an important role in giving comfort to the driver and passengers while driving. The level of hardness can be changed by controlling the flow of hydraulic oil flow in the shock absorbers between piston during the process of compression and rebound. There will be a control unit to control the damping ratio. It adjusted to 4 different levels of hardness. The modifications on inner parts of the shock absorber was done to meet the requirements of the design. Several test procedures have been chosen to evaluate the dynamic behavior of the vehicle. The tests were done bumpy, straight line and roundabout road, these tests used to make objective measurements for evaluation of the acceleration and ride quality performance. Data was analyzed in effectiveness on vehicle acceleration. Ride quality and comfort was considered as well. the result shows the range is fallen in area of little uncomfortable

Oscillatory behavior of chromospheric fine structures in a network and a semi-active regions

In the present work, we study the periodicities of oscillations in dark fine structures using observations of a network and a semi-active region close to the solar disk center. We simultaneously obtained spatially high resolution time series of white light images and narrow band images in the H$\alpha$ line using the 2D G\"ottingen spectrometer, which were based on two Fabry-Perot interferometers and mounted in the VTT/Observatorio del Teide/Tenerife. During the observations, the H$\alpha$ line was scanned at 18 wavelength positions with steps of 125 m\AA. We computed series of Doppler and intensity images by subtraction and addition of the H$\alpha$ $\pm$ 0.3 \AA\ and $\pm$ 0.7 \AA\ pairs, sampling the upper chromosphere and the upper photosphere, respectively. Then we obtained power, coherence and phase difference spectra by performing a wavelet analysis to the Doppler fluctuations. Here, we present comparative results of oscillatory properties of dark fine structures seen in a network and a semi-active region.Comment: 8 pages, 5 figures, accepted for publication in MNRA