Measuring device and measuring method using tape core wire
An object of the present disclosure is to provide a method and an apparatus for acquiring curvature and torsion using an inexpensive sensor medium. Disclosed is a measurement apparatus including a fiber ribbon including a plurality of coated fibers arranged in parallel, a strain measurement unit that measures strain amounts of the plurality of coated fibers, and an arithmetic processing unit that calculates curvature and torsion of the fiber ribbon using a strain amount of a coated fiber arranged in a middle portion of the plurality of coated fibers and a strain amount of a coated fiber arranged in a marginal portion of the plurality of coated fibers.
1. A measurement apparatus comprising:
a fiber ribbon including a plurality of coated fibers arranged in parallel;
a strain measurement unit configured to measure strain amounts of the plurality of coated fibers; and
an arithmetic processing unit configured to calculate curvature and torsion of the fiber ribbon using a strain amount of a coated fiber arranged in a middle portion of the plurality of coated fibers and a strain amount of a coated fiber arranged in a marginal portion of the plurality of coated fibers.
2. The measurement apparatus according to claim 1 , further comprising
a storage unit configured to store a relationship between curvature and a strain amount and a relationship between torsion and a strain amount, wherein
when a variation in the strain amount of the coated fiber arranged in the middle portion of the plurality of coated fibers is substantially equal to a variation in the strain amount of the coated fiber arranged in the marginal portion of the plurality of coated fibers, the arithmetic processing unit derives curvature corresponding to the strain amounts measured by the strain measurement unit using the relationship between the curvature and the strain amount stored in the storage unit, and
when the variation in the strain amount of the coated fiber arranged in the middle portion of the plurality of coated fibers is different from the variation in the strain amount of the coated fiber arranged in the marginal portion of the plurality of coated fibers, the arithmetic processing unit derives torsion corresponding to the strain amounts measured by the strain measurement unit using the relationship between the torsion and the strain amount stored in the storage unit.
3. The measurement apparatus according to claim 1 , wherein
the fiber ribbon is preliminarily twisted,
the measurement apparatus further comprises a storage unit configured to store a relationship between torsion and a strain amount of the fiber ribbon and a reference value of strain caused by the preliminary twisting, and
the arithmetic processing unit determines that twisting is added in a direction identical to a direction of the preliminary twisting of the fiber ribbon when the strain amounts of the plurality of coated fibers are each more than the reference value, and determines that twisting is added in a direction opposite to the direction of the preliminary twisting of the fiber ribbon when the strain amounts of the plurality of coated fibers are each less than the reference value.
4. A measurement method performed by a measurement apparatus, the measurement apparatus being connected to a fiber ribbon including a plurality of coated fibers arranged in parallel, the measurement method comprising:
measuring, by the measurement apparatus, strain amounts of the plurality of coated fibers; and
calculating, by the measurement apparatus, curvature and torsion of the fiber ribbon using a strain amount of a coated fiber arranged in a middle portion of the plurality of coated fibers and a strain amount of a coated fiber arranged in a marginal portion of the plurality of coated fibers.