Augmented reality and deep learning based system for assisting assembly process

In Industry 4.0, manufacturing entails a rapid change in customer demands which leads to mass customization. The variation in customer requirements leads to small batch sizes and several process variations. Assembly task is one of most important steps in any manufacturing process. A factory floor worker often needs a guidance system due to variations in product or process, to assist them in assembly task. Existing Augmented Reality (AR) based systems use markers for each assembly component for detection which is time consuming and laborious. This paper proposed utilizing state-of-the-art deep learning based object detection technique and employed a regression based mapping technique to obtain the 3D locations of assembly components. Automatic detection of machine parts was followed by a multimodal interface involving both eye gaze and hand tracking to guide the manual assembly process. We proposed eye cursor to guide the user through the task and utilized fingertip distances along with object sizes to detect any error committed during the task. We analyzed the proposed mapping method and found that the mean mapping error was 1.842 cm. We also investigated the effectiveness of the proposed multimodal user interface by conducting two user studies. The first study indicated that the current interface design with eye cursor enabled participants to perform the task significantly faster compared to the interface without eye cursor. The shop floor workers during the second user study reported that the proposed guidance system was comprehendible and easy to use to complete the assembly task. Results showed that the proposed guidance system enabled 11 end users to finish the assembly of one pneumatic cylinder within 55 s with average TLX score less than 25 in a scale of 100 and Cronbach alpha score of 0.8 indicating convergence of learning experience.