Investigation of dual varying area flapping actuator of a robotic fish with energy recovery

Autonomous under-water vehicles (AUV) performing a commanded task require toutilize on-board energy sources. At the time when on-board power source runs low duringoperation, the vehicle (AUV) is forced to abort the mission and to return to a charging station.The present work proposes the technique of an energy recovery from surrounding medium. Thiseffect is studied for dual action actuator movement that obtains energy from fluid. It is realizedthat a flapping or vibrating actuator can be used for energy extraction phenomenon apart from thenon-traditional propulsive technique. In the present work a simple dual flapping actuator that canswitch between simple flat plate and perforated plate at extreme end positions (angles) by usingan efficient mechatronic mechanism that would help in overcoming viscous forces of theoperating medium is extensively studied. The main objective of the present article is to developa new approach for energy gain and recharge power pack of on-board sources from thesurrounding medium and to create a robotic fish that would work autonomously by usingunconventional drive along with the possibility of energy restoration by using dual varying areatype vibrating actuator. At the time of recharge, the robotic fish would project its tail (actuator)out of water and use surrounding medium (air) to scavenge the energy. All the equationsdescribing the process are formed according to classical laws of mechanics. The mechatronicsystem is explained and the results obtained are discussed in detail for air as the operating fluidto scavenge energy.