An innovative tactile sensor roller for composites inspection

A vision-based tactile sensor roller prototype has been designed and developed to detect defects on composite prepreg and dry fabric surfaces. The tactile sensor features an innovative design comprising a transparent acrylic tube encased in a gel elastomer. The outer tube serves as a protective and flexible layer, while the inner structure includes a connecting shaft equipped with a camera, force, and speed sensors. This configuration allows for detailed capture of tactile information, integrating visual and pressure data for comprehensive sensory feedback. The connecting shafts are fitted with wheels and handles at both ends, enabling human manipulation and control. Typical defects such as wrinkles, gaps, overlaps and foreign objects and debris (FOD) can be detected by this prototype. In this study, we assessed the performance of the tactile sensor roller by rolling it across areas affected by human-made composite prepreg and dry fabric defects that include wrinkles and foreign objects. With the comparison of the tactile image results, we have demonstrated that the tactile sensor roller can identify flaws with a precision of 0.125mm. It can efficiently examine a 35cm by 18cm section of woven fabric without compromising the integrity of the 3D data gathered. This innovative tactile sensor is set to enhance the automation of the hand layup process. It enables real-time quality control, substantially reducing the need for extensive manual inspections. This leads to a significant cut in inspection costs, making the manufacturing process both more efficient and cost-effective.