Fastener identification and assembly verification via IR tracking

Abstract

Purpose -The purpose of this paper is to create an assembly verification system that is capable of verifying complete assembly and torque for each individual fastener. Design/methodology/approach -The 3D position of the tool used to torque the fastener and the assembly pallet will be tracked using an infrared (IR) tracking system. A set of retro-reflective markers are attached to the tool and assembly while being tracked by multiple IR cameras. Software is used to triangulate the relative position of the tool in order to identify the fastener being torqued. The torque value is obtained from the tool controller device. By combining the location of the tool and the torque value from the tool controller, assembly of each individual fastener can be verified and its achieved torque recorded. Findings -The IR tracking is capable of tracking within 2-3 mm for each tracking ball, with a resulting practical resolution of 24 mm distance between fasteners while maintaining 99.9999 per cent reliability without false positive fastener identification. Research limitations/implications -This experiment was run under simulated assembly line lighting conditions. Practical implications -By being able to verify assembly reliably, the need for manual torque check is eliminate and hence yield significant cost savings. This will also allow programming electric tools according in real time based on the fastener in proximity identification. Originality/value -Currently, assembly verification is only done using the torque values. In automated assembly line, each process might involve fastening multiple fasteners. Using this system, a new level of assembly verification is achieved by recording the assembled fastener and its associated torque.

Optimised multi-camera systems for dimensional control in factory environments

“…As an example, an OptiTrack system has been employed to identify fastener locations for assembly verification in the automotive industry. 24 Static error levels are reported as 60.1 mm for spherical targets; however, the performance deteriorates to 62-3 mm for dynamic tracking.…”

Study on fatigue life of ballastless track fastener springs based on a fatigue test

“…The spring strip is one of the core components of the fastener system, and it is also the most vulnerable component to fatigue damage in the fastener system (Bösterling, 2011(Bösterling, /2013Koh et al, 2016;Zhao, 2005;Wang et al, 2015). When the train is running on the ballastless track of high-speed railway, it will produce working load and vibration load on the lower part, as well as their joint action, and then these loads are transmitted to the fastener elastic strip through the rail, which is the source of the fatigue cycle load on the elastic strip (Zhao et al, 2012;Sol-Sánchez et al, 2015;Krüger, 2000;Koh et al, 2016;Diego et al, 2010;Ren et al, 2016;Rusli and Luscher, 2012).…”

Fastener identification and assembly verification via machine vision

“…A similar need for indoor tracking in assembly environment was addressed using an infrared (IR) tracking system to track the position and orientation of the tool in 3D space (Rusli and Luscher, 2012). By matching the tracking data with known positions of the fasteners, the identification data was used to complete the assembly verification system.…”