Photovoltaic bracket bolt tightening detection

What is the importance of bolt tightening force measurement & loosening detection?

The identification of bolt tension is therefore of great significance for monitoring the health of existing structures. This paper reviews state-of-the-art research on bolt tightening force measurement and loosening detection, including fundamental theories, algorithms, experimental set-ups, and practical applications.

How can we detect loosening severities in in-situ bolted connections?

Loosened bolts in the lab-scale and real-scale joints are well detected with precisely-estimated loosening severities, even for a sharp perspective angle. The method also shows a high level of adaptability with low-brightness images. Therefore, the method has great potentials for autonomous monitoring of in-situ bolted connections. 1. Introduction

What are the results of detecting bolts using the Faster RCNN?

The results include (i) detecting bolts using the Faster RCNN; (ii) detecting four corners of the boundary formed by the centres of detected bolts; (iii) correcting perspective distortion; (iv) detecting bolts in the corrected image; (v) cropping detected bolts; and (vi) estimating the angle of detected bolts.

Can autonomous vision-based bolt-looseness detection be used for splice bolted connections?

This study presents a novel autonomous vision-based bolt-looseness detection method for splice bolted connections. The method is sequentially designed with a Faster regional convolutional neural network-based bolt detector, an automatic distortion corrector, an adaptive bolt-angle estimator, and a bolt-looseness classifier.

Can a bolt-loosening angle be detected with a UAV?

The method can detect a minor bolt-loosening degree of 5 o and the allowable perspective angle can be up to 40 o [19, 21]. Moreover, the method has great potentials to integrate with a UAV for monitoring inaccessible bolted connections in the field .

How do vibration-based methods correlate with bolt clamping tightness?

Other vibration-based methods correlate the local mode frequency of bolted joints or the signature parameters from PDF or FRF analysis to bolt clamping tightness. Some pattern recognition techniques were employed to improve the identification ability of these indicators.