Robotic Theodolites (RTS)

摘要

Robotic theodolites, the new generation of the well-known surveying theodolite, are used to measure deflections in short-span bridges with millimetre accuracy. This permits the coming true of an old dream for engineers: to be in a position not only to predict, but to measure the excitation of engineering structures due to dynamic loads such as wind and traffic, and hence evaluate their structural health. Electronic theodolites or total-stations (TS) are very common survey instruments used to compute the Cartesian coordinates of selected points marked by a usually prismatic reflector. A TS emits a modulated IR ray to the reflector, measures 'time-of-flight' (TOF) of emitted ray, and reflects back to the TS and computes the distance to the reflector. In addition, it measures zenithal and horizontal angles of the sighting point relative to a selected point. Measured polar coordinates of the point marked by the reflector are subsequently transformed into Cartesian coordinates relative to a selected reference system, with millimetre, and even sub-millimetre accuracy.