Opto-mechanical tilt sensor using moiré effect for slope movement remote sensing

Novel moiré‐based crack monitoring system with smartphone interface and cloud processing

“…The idea of using moiré patterns as sensors was extended to slope movement sensing in several interrelated works. [19][20][21][22] A novel tilt sensing device was designed and developed for sensing tilt in any arbitrary plane. The sensor composed of two overlapping pitch mismatched gratings mounted inside a water-filled sealed chamber.…”

“…Various experiments were carried out, such as repeatability of moiré patterns when using different types of liquids in the chamber 19 and study of relationship between the peak-to-valley height of the transformed polar curve and tilt angle. 20 In a recently published work, 22 a method to automatically analyze the moiré fringes and extract features that can be used to sense tilt angles was proposed. The moiré patterns were subjected to several sequential image processing operations, such as low-pass filtering, polar transformation, column-wise polynomial fitting, fringe center tracking, unwrapping, and sine function fitting.…”

“…The idea of using moiré patterns as sensors was extended to slope movement sensing in several interrelated works . A novel tilt sensing device was designed and developed for sensing tilt in any arbitrary plane.…”

“…One of the gratings was fixed, whereas the other was mounted on a float and attached to ball joint that can rotate about any arbitrary plane. Various experiments were carried out, such as repeatability of moiré patterns when using different types of liquids in the chamber and study of relationship between the peak‐to‐valley height of the transformed polar curve and tilt angle . In a recently published work, a method to automatically analyze the moiré fringes and extract features that can be used to sense tilt angles was proposed.…”