Design and Implementation of a Regenerative Shock Absorber

In this thesis, the development of a novel regenerative shock absorber sized for a passengercar suspension system is studied. In the first phase, DC and AC rotary machines along with charging circuits, to be used in the energy conversion stage of the proposed shock absorber are analyzed. In this analysis, the rotary damping coefficients provided by these systems are obtained following by experimental results.In the second phase, the development of a novel regenerative shock absorber in a proof of concept setting is presented. This system consists of a new linear-to-rotary conversion mechanism called algebraic screw, a gearhead, and a rotary machine. The design and analysis of this system is presented. The linear damping coefficient provided by this shock absorber is obtained. Experimental results are presented that evaluate performance of the proposed system on a small-scale suspension system.In the third phase, the development of a novel regenerative shock absorber sized for a passenger car is presented. The shock absorber includes a simple and highly efficient motion converter stage called ”two-leg mechanism”, a planetary gearhead, and a brushless three-phase rotary machine. The design and analysis of the regenerative shock absorber is presented by considering the linear damping coefficient and efficiency of the electromechanical device. The performance of the regenerative shock absorber is evaluated under sinusoidal excitation inputs for typical amplitudes and frequencies in a vehicular suspensionsystem.In the fourth phase, the effect of nonlinear terms of the shock absorber on linear dampingcoefficient provided by this system is studied. Next, the idea of using a variable externalresistance, provided by the charging circuit, to compensate the nonlinear terms is presented.