Next force sensing technology for robots: multi-axis resonant sensors

The aim of this paper is to present a novel resonant multi-axis force sensor with applications in robotics. A resonant force sensor is characterized by the use of a frequency output signal to estimate the applied forces, instead of using its amplitude as it is often the case for the other existing technologies used in robotics. The advantages of resonant force sensing for robotics are discussed, especially for the safety requirements in the collaborative field. We extend our analysis to show the main similarities and differences between more classical sensors (based on strain gages for instance) and resonant ones, with a focus on their design. More specifically, we detail the way the design of the sensitive element, which essentially transduces the applied forces into frequencies, plays a major role on its performances.