Synthesis of a semi-active suspension seat for attenuation of Whole-Body Vibration and shock

Abstract

In this study, two semi-active control algorithms are synthesised on the basis of the measured nonlinear force-velocity properties of a Magneto-Rheological (MR) damper, including the current-dependent hysteresis and post yield saturation. The control algorithms employ the well-known sky-hook control condition function, suspension travel limits and a modulation function to compensate for the switching discontinuities. The results show that the proposed semi-active control synthesis could help achieve improved shock isolation while retaining adequate control of continuous WBV. A Hardware-In-the-Loop (HIL) test and simulation platform are developed for tuning of the proposed semi-active controllers and validation of the analytical formulations.Reference to this paper should be made as follows: Ma, X.Q., Rakheja, S. and Su, C-Y. (2008) 'Synthesis of a semi-active suspension seat for attenuation of Whole-Body Vibration and shock', Int. J. Vehicle Design, Vol. 47, Nos. 1/2/3/4, pp.157-175. Biographical notes: Xiao Qing Ma received her MSc and PhD in Mechanical Engineering at Concordia University, Montreal, Canada, in 2001 and 2006.Her research covers vehicle vibration analyses and control, modelling and simulation for mechanical system, robotics and advanced manufacturing technologies, and non-linear or linear control system. She is currently a postdoctoral fellow in robotic mechanical system laboratory, centre for intelligent machines, in McGill University, Montreal, Canada.Subhash Rakheja obtained his BEng and PhD in Mechanical Engineering at Concordia University, Montreal, Canada. His research interests include advanced transportation systems and highway safety, human responses to workplace vibration and driver-vehicle interactions. His research work in this area has evolved to what is called vehicular ergodynamics, a field that involves systematic studies on the dynamics of the transport system coupled with the human operator, with a special emphasis on the dynamic interactions.Chun-Yi Su received his BE degree in Control Engineering from Xian University of Technology in 1982, his ME and PhD degrees in control 158 X.Q. Ma et al. where he is currently a Professor of Mechanical Engineering and holds the Concordia Research Chair in Control. His research covers control theory and its applications to various mechanical systems. His current main research interests are in control techniques for smart material based actuators, vehicle suspension and vibration, robotic and mechatronic systems, and fuzzy control for non-linear systems.

Modeling and validation of off-road vehicle ride dynamics

“…The above coherence function can also be expressed accurately by a second-order function of the form: Eqs. (15) and (17), as shown in Fig. 7.…”

“…The most popular preventive measure of WBV exposure reduction has been the suspension at the seat, which limits only vertical vibration [15][16][17]. A suspension seat, however, yields limited isolation of high intensity vertical vibration encountered in many off-road vehicles, which may in-part be attributed to lack of suspension tuning with regard to the intensity and frequency contents of the target vehicle vibration [17]. A number of studies have also explored different cab suspension designs [18,19].…”

“…These suspensions, however, are not effective in limiting the transmission of fore-aft and lateral vibration, whose magnitudes are known to be either comparable to or exceed that of the vertical vibration [10,20]. In addition, performance of secondary suspensions, generally derived from subsystem models of the seat and cab suspensions [16][17][18][19][20], may be also limited due to lack of consideration of dynamics of the target vehicle [13]. Although axle suspensions offer greater potential to reduce translational as well as rotational vibrations, relatively fewer studies have attempted design and performance analyses of such suspensions, where the enhancements in ride have been clearly demonstrated [21][22][23][24][25][26].…”

Hybrid sensor network control of vehicle ride comfort, handling, and safety with semi-active charging suspension

“…Unsurprisingly, a classical semi-active suspension is characterized by variable damping, the electronic modulation of which is obtained using magnetorheological (MR), electrorheological (ER), or electrohydraulic techniques. 3 An MR/ER damper could be used to provide a variable damping force modulated by varying the command current. As a result, it has attracted considerable interest from both the academic community as well as auto manufacturers.…”

H∞ control for a semi-active scissors linkage seat suspension with magnetorheological damper

“…The vehicle ride quality has attracted increasing attention since its impact on drivers' fatigue, health, and discomfort, due to severe environments such as rough road conditions (Choi and Han, 2003;Gad et al, 2015;Ma et al, 2008;Rakheja and Afework, 1994). The vibration caused by road conditions finally is transferred through chassis and seat to human body.…”