The real “golden age” of electronic suspension can be probably located in the 1980s; during that decade the exceptional potential of replacing a traditional spring-damper system with a fully fledged electronically controllable fast-reacting hydraulic actuator was demonstrated. High costs, significant power absorption, bulky and unreliable hydraulic systems, and uncertain management of the safety issues: the fatal attraction for fully active electronic suspensions lasted only a few years. In the second half of the 1990s, a new trend emerged: it became increasingly clear that the best compromise of cost (component cost, weight, electronics and sensors, power consumption, etc.) and performance (comfort, handling, safety) was to be found in the technology of electronically controllable suspensions: the variable-damping suspension or, in brief, the semi-active suspension. After a decade this technology is still highly promising and attractive: it has been introduced in the mass-market production of cars; it is entering the motorcycle market; a lot of special vehicles or niche applications are considering this technology; many new variable-damping technologies are being developed. Semi-active suspensions are expected to play an even more important role in the emerging trend of electric vehicles with in-wheel motors: in such a vehicle architecture the role of suspension damping is more crucial, and semi-active suspensions can significantly contribute to reduce the negative effects of the large unsprung mass. As in many other electronically controlled systems, the actuator is not “smart itself”: it simply inherits the smartness (or dumbness) of its control algorithm designer. The key of semi-active suspensions is in the algorithm. For the discussed reasons, this paper briefly reviews the basic theoretical concepts for variable-damping shock absorber technologies and the available control algorithms.

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Abstract:In this paper a modified parametric algebraic model was proposed to capture the hysteretic behaviour of the Magnetorheological (MR) damper. The superiority of the proposed modified model was shown by comparing it with the algebraic model. It is observed that although two models are comparable at lower voltage inputs of 1V, 2V and 3V the modified algebraic model is remarkably successful at higher voltage inputs of 5V and 7V at the highest excitation velocity of 200m/s over the algebraic model. Apart from its accuracy, modified algebraic model is also more preferable in terms of its low computational expenses compared to differential modified Bouc-Wen's model which is highly computationally demanding. Therefore it was concluded that the proposed modified algebraic model can be used to develop more effective control algorithms for such devices.

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