The assembly automation challenge was to move from a semi-automatic solution and provide a fully automatic solution to build a ‘tile’ consisting of 152 layers of fibre optic wafers. The wafers had to be positioned exactly, each time, otherwise the quality of the final product (display screen) was impaired.
A short Design Study and Risk Assessment determined this application called for a transport and handling system with a high degree of positioning accuracy (in all directions) and tightly controlled accelerations and decelerations, to avoid damaging the product whilst maintaining very short index cycles. Market research determined no suitable commercially available system could be found.
We developed our own.
The system utilised servo positioning, special belts with custom flights, a precision guide rail, easy to set precision stops (independent of the transport conveyor) and low cost pallets with remote ID tags. It was possible to position each pallet within 0.1mm (max) in XY and Z repeatedly at each of the process stations in the system. The ID tag enabled the machine to compensate for variations in the product and individual pallets, whilst the machine recorded the status of the product as it progressed through a number of repeated cycles required during its build. The result was a simple pallet system that decouples the tolerances of the machine and pallets from those of the product.
A bedrock of a complex system utilising robot handling, precision gluing, cutting and an integral vision system for product control. End product quality was improved, with less wastage, and speed of manufacture increased.