Resonant force sensor using a PLL electronic

Christine Barthod (1) , Yves Teisseyre (1) , Claudine Gehin (2) , Gérard Gautier (1)

1 SYMME - Laboratoire SYstèmes et Matériaux pour la MEcatronique
2 LGEF - Laboratoire de Génie Electrique et Ferroélectricité

The working principle of resonant force sensors with double ended tuning forks (DETF) consists of measuring one of the resonant frequencies of the vibrating beams which depend on the force applied in the beams. Although the principle is simple, its practical application presents some problems. The principal difficulties in the design of such a structure lie in two principal points dealing with the mounting of the DETF on its support and with the mechanical resistance of the structure. In order to approach the ideal structure, the proposed force sensor is based on a DETF directly machined in a metallic circular plate. The force to be measured is applied on the plate by using a tube. The sensor has been designed using finite element simulations. An electronic circuit including both analog PLL and logic circuitry parts has been developed for frequency shift measurement, dedicated to this sensor. A prototype has been realized and tested which gives promising results; the principal technical features of the prototype are reported.

Mots clés: Force; Resonance; Sensor; Finite element simulation; PLL electronic

Domaines: Matériaux et structures en mécanique [physics.class-ph]; Matériaux et structures en mécanique [physics.class-ph]

Christine Barthod, Yves Teisseyre, Claudine Gehin, Gérard Gautier. Resonant force sensor using a PLL electronic. Sensors and Actuators A: Physical , 2003, 104 (2), pp. 143-150. ⟨10.1016/S0924-4247(03)00005-0⟩. ⟨hal-00258212⟩