Recently, industrialized nations’ huge investment in building civil infrastructure sparked researcher’s interest to offer solutions for long-term autonomous monitoring of structures in order to ensure integrity of these valuable assets. On the other hand, it is also realized to continuously monitor aging infrastructure for public safety assurance. Non destructive evaluation of structure through continuous monitoring is most promising way to assess the structure reliability before any unforeseen collapse. Cracks formation and expansion may be the earliest tell-tale signs of possible structure collapse. So, every crack should be monitored when it appear first time. Visual inspection is the most widely used approach for crack monitoring but it can not be used for long-term continuous monito...[ Read more ]

Recently, industrialized nations’ huge investment in building civil infrastructure sparked researcher’s interest to offer solutions for long-term autonomous monitoring of structures in order to ensure integrity of these valuable assets. On the other hand, it is also realized to continuously monitor aging infrastructure for public safety assurance. Non destructive evaluation of structure through continuous monitoring is most promising way to assess the structure reliability before any unforeseen collapse. Cracks formation and expansion may be the earliest tell-tale signs of possible structure collapse. So, every crack should be monitored when it appear first time. Visual inspection is the most widely used approach for crack monitoring but it can not be used for long-term continuous monitoring. There are some displacement sensors capable of precise crack width measurement but these sensors are incapable of large scale deployment because of very high cost, wiring involved in sensing to data logging units and incapability to measure 2-dimensional displacement.

In this thesis, we are proposing energy aware consistent and long-term crack monitoring by using inexpensive optical navigation technology and harvesting solar energy. The sensor is installed across the crack with one end fixed on one side of crack. On the other side of the crack, the optical navigation sensor acquires images through its image acquisition system. In order to estimate crack propagation, relative displacement is computed between sequential images through optical flow algorithm. The major challenge in crack width monitoring with self-sustainable sensor is to consistently perform sensing cycles within limited and unpredictable harvested ambient energy. In order to address this problem, we are presenting efficient solar harvested energy prediction algorithm based on additive decomposition model. This algorithm consists of three terms along with three tuning parameters. First term estimates daily energy prediction based on the previous history. Second term introduces seasonal change and third term establish solar harvested energy trend on current day. Based on this energy prediction algorithm, we are proposing dynamic energy allocation scheme in order to perform consistent crack monitoring over time.