Power harvesting in a helicopter lag damper

Currently the lifespan of rotor blades is determined based on a conservative lifetime calculation. This leads to blades being discarded while they still possess a significant residual amount of flight-hours. Blade health monitoring systems are desired to actively track the strains in the blade thereby drastically extending the technical life expectancy. A major drawback is in the need for an electrical infrastructure to transmit all the signals to and from the rotor hub to aircraft body. It would be advantageous if the required power could be generated locally. Within the European Clean Sky project vibration-based power harvesting is chosen as a solution to powering in-blade health monitoring systems. In this paper a new power harvesting application is developed and simulated. Local generation of power will allow for a ‘plug and play’ rotor blade and signals may be logged or transmitted wirelessly to the body of the aircraft. Examples are the blade strains, hinge forces, vibrations and so on.