COMPACT FIBER-OPTIC UNIT SENSING 3 ORTHOGONAL DIRECTIONS SIMULTANEOUSLY

摘要

Each fiber-optic gyroscope unit is shaped like a tetragonal cone. A square plate (51) is used as a base which holds a light source module (52), a light receiving unit (detector) (53) and an optical fiber coil (54). Directional couplers (56) are also mounted on the base (51). A phase modulator (55) which includes a piezoelectric element is disposed inside the optical fiber coil (54). A signal processing circuit board (58) which has pedestals (59) stands on the base (51) such that it positions above the optical fiber coil (54). A polarizer (510) is wound around the optical fiber coil (54). A reinforcement member (511) is also provided. All these components are so arranged as not to extend out of the tetragonal cone (OABCO*) which defines its own unit region. Three identical fiberoptic gyroscope units are combined by connecting members (512, 513, 514) to form a single fiber-optic gyroscope to detect rotational angular velocities about three orthogonal axes. Since identical units (50) are used, the assembly is easy, and since the three units (50) are combined with respect to the axis of symmetry, the combined units (50) form a compact gyroscope.