Award Date


Degree Type


Degree Name

Master of Science (MS)


Electrical Engineering

First Committee Member

Sahjendra N. Singh

Number of Pages



In this thesis the problem of control of semi-active devices (MR damper, MR elastomer) for shock isolation systems are considered. Semi-active control systems combine the best features of both the passive and active control systems, offering the reliability of passive devices, yet maintaining the versatility and adaptability of fully active devices. First the question of stability and control of a two degree-of-freedom magnetorheological (MR) fluid damper shock isolation system is considered. It is shown that for any arbitrarily time varying input current, the system is absolutely stable. This explains the shock isolation capability of the MR damper system even with control laws clamped in an ad hock way to limit the control magnitude. Then a nonlinear inverse (feedback linearizing) control law and a nonlinear suboptimal control law based on the state-dependent Riccati equation (SDRE) method are designed for the shock isolation of the payload mass. For the inverse control law derivation, the inertial position of the payload is chosen as the controlled output variable. For the design via the SDRE method, constraint on the input current is introduced and a quadratic performance index is chosen for minimization. It is shown that in the closed-loop system the inverse and suboptimal control laws are effective in shock isolation of the payload mass; Secondly, the mathematical modeling and predictive control of a magnetorheological fluid damper system is considered. (Abstract shortened by UMI.).


Active; Control; Isolation; Semi; Shock; Techniques

Controlled Subject

Electrical engineering

File Format


File Size

1617.92 KB

Degree Grantor

University of Nevada, Las Vegas




If you are the rightful copyright holder of this dissertation or thesis and wish to have the full text removed from Digital Scholarship@UNLV, please submit a request to and include clear identification of the work, preferably with URL.


IN COPYRIGHT. For more information about this rights statement, please visit