This paper describes SHAPE TAPE , a thin array of fiber optic curvature sensors laminated on a ribbon substrate, TM arranged to sense bend and twist. The resulting signals are used to build a three dimensional computer model containing six degree of freedom position and orientation information for any location along the ribbon. The tape can be used to derive dynamic or static shape information from objects to which it is attached or scanned over. This is particularly useful where attachment is only partial, since shape tape "knows where it is" relative to a starting location. Measurements can be performed where cameras cannot see, without the use of magnetic fields. Applications include simulation, film animation, computer aided design, robotics, biomechanics, and crash testing.

No abstract

No abstract

No abstract

Measurement of sub-millimetre-level deformations of structures in the presence of ambient temperature changes can be challenging. This paper describes the measurement of a structure moving due to temperature changes, using two ShapeAccelArray (SAA) instruments, and verified by a geodetic monitoring system. SAA is a geotechnical instrument often used for monitoring of displacements in soil. SAA uses micro-electromechanical system (MEMS) sensors to measure tilt in the gravity field. The geodetic monitoring system, which uses ALERT software, senses the displacements of targets relative to control points, using a robotic total station (RTS). The test setup consists of a central four-metre free-standing steel tube with other steel tubes welded to most of its length. The central tube is anchored in a concrete foundation. This composite “pole” is equipped with two SAAs as well as three geodetic prisms mounted on the top, in the middle, and in the foundation. The geodetic system uses multiple control targets mounted in concrete foundations of nearby buildings, and at the base of the pole. Long-term observations using two SAAs indicate that the pole is subject to deformations due to cyclical ambient temperature variations causing the pole to move by a few millimetres each day. In a multiple-day experiment, it was possible to track this movement using SAA as well as the RTS system. This paper presents data comparing the measurements of the two instruments and provides a good example of the detection of two-dimensional movements of seemingly rigid objects due to temperature changes.