POIS, a Low Cost Tilt and Position Sensor: Design and First Tests

Abstract

An integrated sensor for the measurement and monitoring of position and inclination, characterized by low cost, small size and low weight, has been designed, realized and calibrated at the Geomatics Lab of the University of Calabria. The design of the prototype, devoted to the monitoring of landslides and structures, was aiming at realizing a fully automated monitoring instrument, able to send the data acquired periodically or upon request by a control center through a bidirectional transmission protocol. The sensor can be released with different accuracy and range of measurement, by choosing bubble vials with different characteristics. The instrument is provided with a computer, which can be programmed so as to independently perform the processing of the data collected by a single sensor or a by a sensor network, and to transmit, consequently, alert signals if the thresholds determined by the monitoring center are exceeded. The bidirectional transmission also allows the users to vary the set of the monitoring parameters (time of acquisition, duration of satellite acquisitions, thresholds for the observed data). In the paper, hardware and software of the sensor are described, along with the calibration, the results of laboratory tests and of the first in field acquisitions.

TLS for Dynamic Measurement of the Elastic Line of Bridges

“…In addition to a digital level and a total station; some strain sensors were placed both on the pylon and in various positions on the deck. Furthermore, two inclination sensors provided inclination at different pylon heights in real time, thanks to a wireless connection [35].…”

Monitoring of Structures by a Laser Pointer. Dynamic Measurement of Rotations and Displacements of the Elastic Line of a Bridge: Methodology and First Test

“…For the calibration of the camera, an upgrade of a well-known procedure [22,23], developed using Matlab®, has been used. The procedure has been applied to the NIKON D610 camera with a 55 mm NIKKOR lens configured with a HD frame (1920 x 1080).…”

TLS and GB-RAR Measurements of Vibration Frequencies and Oscillation Amplitudes of Tall Structures: An Application to Wind Towers

“…Among the various techniques proposed for measuring the frequencies of structures, those based on the acquisition of accelerometers and velocimeters have been widely used for decades [4,5]. The use of micro-electro-mechanical systems (MEMS)-based sensors and wireless connected sensors is growing, in order to set up even very dense control networks [6,7]. Global navigation satellite system (GNSS) receivers offer the possibility of extracting vibration frequencies [8]; as for the aforementioned techniques, the limit of GNSS is the point-like property of its measurements; moreover, it is necessary to position the GNSS receiver on the point to be monitored.…”