GAIKER continues the analysis of the WEEE management scheme to detect which actions of the human-robot collaboration can be more relevant saving time and reducing efforts to workers
GAIKER is completing additional analysis of the WEEE management scheme by studying the details associated to the involved classification, dismantling and sorting steps. Every activity is being described based on its specific characteristics, as the necessary time to pick waste equipment from piles and place it on classified batches or the required tools to release joining systems and dismantle selected parts and components. The primary information, that was provided by the end-users, related to aspects as overall material flows inside the plants or to specific disassembly sequences of every equipment type, is being processed to detect which activities can be more relevant to turn from manual to human-robot collaborative. The obtained data will be further used in the project to tune the HR-RECYCLER approach accordingly, to maximize the benefits achieved from the implementation of the human-robot collaboration.The material flow analysis confirmed that 65-75 % of the WEEE arriving to the plants needs selective treatment. It was also stated that, depending on the characteristics of each unit or the layout of the plant and the technologies that incorporates, a person, during one hour of work, can classify 200-500 kg of appliances and generate 80-400 kg of decontaminated devices and separated parts.The study of dismantling sequences, that are mainly focused on the extraction of potentially hazardous components and the recovery of valuable parts, showed that, in all cases, the removal of the external covers demands the unscrewing of joining systems and the grasping of the liberated elements to be sorted. On the other hand, the release of internal components or parts can involve diverse actions as a gentle detach from connectors (case of mercury lamps in flat panel displays and emergency lighting devices), the cutting of cables (case of capacitors in microwave ovens) or the vigorous extraction of batteries (case of PC towers).After completing the analysis, the use of the pallet-truck and the robotic arm in the classification area, the development of the unscrewing action using the collaborative-robot in the dismantling area and the use of the AGV with a built-in robotic arm in the sorting area have been identified as priorities.Additionally, the screening of several videos, showing the current applied procedures, allowed the calculation of processing times for each of the dismantling steps with the following results:
Grab a tool: 1.1 ± 0.3 s (n 13)
Release a tool: 1.0 ± 0.2 (n 12)
Extract the objective components: 14.2 ± 13.8 s (n 9)
Loose a screw with an automatic screwdriver: 2.9 ± 0.8 s (n 21)
Cut connecting cables: 3.9 ± 2.1 s (n 4)
Remove housing with no screws: 4.6 ± 2.0 s (n 9)
Figure 1. Selected sequences during the manual disassembling of WEEE
It has been found that the most time demanding operation is the extraction of a component of interest (e.g., capacitor, battery, lamp) as it involves considerable handling work. In addition, it is also the operation whose duration varies the most because some components require skilful and delicate handling because they contain hazardous substances and/or are fragile.Further manual dismantling trials are planned to be performed at GAIKER in the following months, parallel to the initial human-robot collaborative system tests that are taking place at real scenarios. That additional experiments will help to analyse more deeply the manual tasks that are more time demanding and require more effort to workers and will be used to model a realistic collaborative WEEE recycling process with improved technical performance and better working conditions.
