Modeling and design of a motion converter for utilization as a vibration energy harvester

This paper presents the analysis and design of a mechanism to be utilized as a regenerative shock absorber. The device consists of an algebraic screw mechanism, a planetary gearhead, and a DC rotary machine. The algebraic screw is a kinematic mechanism that converts the translational vibration motion into a reciprocating rotary motion which drives a rotary generator. The energy generated by the rotary machine is converted into the battery charge through a power electronic converter. In this study, the amount of damping provided by the shock absorber is analyzed using the dynamic analysis of a quarter car system. To this end, expressions for the input, captured, and lost power are presented in terms of the parameters of the shock absorber and road excitation profile. Simulations are carried out to study the characteristics of design in terms of converting vibration energy into rotary motion. Validation of the model is demonstrated by comparing the simulation and numerical results.