| 主权项 |
1. A micro-machined inertial angular sensor comprising:
two vibrating masses, machined in a generally plane support wafer, which are mobile with respect to the wafer and mobile with respect to one another, suspended from fixed anchoring points of the wafer by suspension springs and coupled together by coupling springs so as to vibrate in phase opposition, at least one transducer for exciting a vibration motion of one of the masses along a direction X in the plane of the wafer, a transducer for exciting this mass along a direction Y perpendicular to the direction X and in the plane of the wafer, a transducer for detecting a vibration of one of the masses along the direction X and a transducer for detecting a vibration of one of the masses along the direction Y, the excitation transducers and detection transducers each comprising a pair of interdigitated combs having a mobile comb formed of a row of teeth fastened to the vibrating mass and a fixed comb formed of a row of teeth fastened to a fixed electrode, the interdigitation of the teeth at rest being dissymmetric, and at least one first frequency adjustment electrostatic transducer, as interdigitated combs with symmetric interdigitation at rest, able to apply an adjustable electrostatic stiffness to the vibrating mass along the direction X, and a second frequency adjustment electrostatic transducer similar to the first and able to apply to the vibrating mass an adjustable electrostatic stiffness along the direction Y, wherein the two mobile vibrating masses are disposed one around the other, as an inner mass and an outer mass, and their centres of gravity coincide at rest, wherein the coupling springs are each linked on one side to the inner mass and on the other to the outer mass and they have identical stiffnesses along the direction X and along the direction Y, wherein the stiffnesses of the springs for suspending the inner mass are identical along the direction X and along the direction Y and the stiffnesses of the springs for suspending the outer mass are identical along the direction X and along the direction Y, and they are proportional to the values of the respective masses, and wherein the mobile assembly consisting of a vibrating mass and the parts of transducers fastened to this mass has a structure which is generally symmetric with respect to an axis of symmetry OX parallel to the direction X and passing through the centre of gravity of the mass, and also generally symmetric with respect to an axis of symmetry OY parallel to the direction Y and passing through the centre of gravity of the mass. |
