A sensorized wheel coated by solid piezoelectric elastomer

Acquiring mechanical information about the state and the mechanical conditions of wheels, rollers or tyres in real-time working conditions is still a significant challenge in transportation and industrial applications. Non-real-time tests represent the most prevalent method for gathering data about rolling element conditions such as applied load, internal strain and stresses. This study proposes a novel solution to sensorize solid wheels, introducing the use of an innovative piezoelectric elastomer already developed and tested by the authors. Its main characteristics, such as softness and intrinsic sensing capability, make it a good candidate for this type of application. We adapted the fabrication process of the elastomer to the realization of a solid wheel coating, through an ambient temperature over moulding process. A custom dedicated testbench was designed and fabricated to test the prototype wheel under rolling at constant vertical load conditions, in a matrix of different test configurations. Results show that output signals are strongly dependent on load, but also on the velocity due to the system design. A juxtaposed FE analysis integrates test results relating the output voltage signals obtained to the mechanical stress condition of the studied wheel.