Study On Dual-Overrunning Clutches Electro-Mechanical Regenerative Damper Concept

Regenerative damper is a new damper concept, which is designed to take place of thetradiational dampers inorder to harness part of the kinetic energy associated with dynamicmotions of the vehicle sprung and un-sprung masses, when traversing randomly roughterrains. In the past two decades, the designs concept, control algorithms and optimizationmethods about the regenerative damper system are proposed. Based on those studies, theelectro-mechanical regenerative solutions are getting more and more popular due to itslight weith, instant response, and reuseable recovered energy. Meanwhile, lots of problemsneed to be resolved about the design of regenerative dampers, such as: the kinetic energyassociate with the low magnitude excitation is hard to be recovered; the recovered energy isdifficult to store in tradiational vehicle solution; the shock caused by the impulse excitationto mechanism components and generator circuit is dramatic. Moreover, energyconsumption is required for the regenerative dampers designed to improve the suspensionisolation performance.Based on the analyze of the designs proposed by other researchers, and the study aboutthe feasibility and potential of regenerative dampers, a new design concept is proposed inthis study, namely the dual-overrunning clutches electro-mechanical regenerative damper,furthermore, two transmission mechanism designs are proposed in this study as well. Theproposed design comprising a worm gear, two overrunning clutches, a planet gearmechanism and an electro-magnetic generator to convert bi-direction linear motion acrossthe damper to a uni-direction rotation of the generator armature. This arrangement resulted in not only relatively higher speed of the generator armature but also asymmetric variations inthe generator speed during compression and rebound damper motions, thus lead to theasymmetric damping. Besides, the"high-low"and"on-off"semi-active damping can also beachieved by taking advantage of the inertia damping and the clutches slippage in a passivemanner. Moreover, the regenerative damper can recover the kinetic energy in full time, andno energy consumption is required.Based on the design concept of the regenerative damper, the asymmetric damping, semi-active damping and the energy recover functions are analyzed. Therefore, the four majorsystem parameters which affect the damper performances are optimized with non-dominatedsorting genetic algorithm. The damping characteristics, energy recover features, the systemisolation features and the effects of the system parameters on the damper performances areanalyzed with the damper model. Meanwhile, the capacitor optimized voltage controlmethod is proposed to enhance the isolation and energy recover ability. According to theanalyzation, the damper response features are mostly dominated by the damper transmissionmechanism and the generator armature circuit parameters, such as the worm gear pitch,mechanism effective inertia, generator torque constant and armature resistance, whichprovide the system design and turning guidance.A prototype regenerative damper is designed and built based on the proposed damperdesign concept. The preliminary laboratory experiments were conducted to characterizeinertial damping properties of the prototype regenerative damper under harmonic excitationsof different magnitudes and frequencies. The testing results verified the method that achivingthe"high-low"semi-active damping in passive manner by taking advantage of the mechanism inertia effect. Such that, the correctness and feasibility of the damper designconcept are also testified.The dual-overrunning clutches electro-mechanical regenerative damper conceptproposed in this study can provide asymmetric damping,"high-low"damping and"on-off"semi-active damping in a passive manner; the energy recover efficiency can also beenhanced.