Pyroelectric Generators to Harvest Energy from Disc Brake Pads for Wireless Sensors in Electric Vehicles

There is a large amount of thermal energy wasted during the driving cycle of all kinds of vehicles. In this paper, a pyroelectric harvester system, based on temperature change, is designed for low-powered sensors for a reliable Electronic/Electric architecture development of autonomous vehicles. For this proposed approach, three main elements are required: Pyroelectric energy harvest module, energy conversion module and power storage module. The energy harvest module includes a pyroelectric material, which captures the temperature of the braking system, and harvests the wasted heat energy during the contact process. In the energy conversion module, the temperature variation through the pyroelectric material generates electricity, given the cooling phenomena with the ambient air. The energy potentially available in the form of heat produced by the friction involved in braking was evaluated using finite element analysis on the Multiphysics software environment. Therefore, we present stimulations of disc heating and cooling during the braking process at different speeds. Moreover, the potential for energy recovery in multiple rolling conditions is discussed, such as the braking cycles and the effect of the material thickness, used in the conversion module. The proposed system has undergone simulation analysis, which shows that the system can generate a voltage of 10.8 V and a power of 7.0 mW for a cycle of one braking process and around 9.5 mW for a cycle containing two successive braking. This result illustrates the feasibility of energy-autonomous applications in low-power sensors for new vehicle generations.