Ambidextrous robots

Citation

Loughlin, C. (2008), "Ambidextrous robots", Industrial Robot, Vol. 35 No. 1. https://doi.org/10.1108/ir.2008.04935aaa.001

Ambidextrous robots

Manufacturing involves holding a part while some action is undertaken on it and then passing it on to the next process until finally the completed product is boxed up and sent to the customer.

Grasping parts that may be presented to you in any orientation or attitude is no simple matter and one of the golden rules of manufacturing is that once you have grasped and aligned a part you do everything you cannot to let go of it again. If you do let go you are then faced with the expensive and time-consuming task of re-grasping it before the next process can be performed.

However, parts do need to be moved between processes and so all sorts of fixtures and molded trays have been developed on which to transport parts while more or less keeping their position and orientation defined.

Imagine that you are tasked with whittling a piece of wood (not an everyday industrial task but I hope it will serve to illustrate the general idea). You will happily sit with the piece of wood in one hand and a pocket knife in the other and beaver away quietly, probably moving the piece from one hand to the other as you modify your grasp to admire your handicraft and position the piece so another area can be whittled.

Now imagine that you only had one arm and were tasked with the same activity. The only way forward would be if the wood could be secured in a vice or some other fixture while the single arm whittled away for a while before having to put down the knife and reposition the part in the vice before continuing.

Clearly this second way of working would be much more time consuming. We would think a two-armed person crazy if they had the ability to use two arms but decided to only use one as outlined above.

However, this is precisely the way we have been using robots for the last 30 or so years.

Henry Ford introduced us to the production line and it was a major revelation at the time. Prior to Ford's innovation manufacturing was centred on the product – be it a table, chest of drawers, or a ship or a train. The product more or less stood still while additional materials and a variety of tools were brought to bear.

The advantage of the production line is that effectively a large number of parts can be worked on at the same time as each resides briefly at a particular workstation before moving on inexorably towards the end of the line. The disadvantage of the production line is that it takes up a lot of room, requires a great deal of capital equipment and normally time is lost as the parts move in transit between one station and the next.

Given today's trend towards mass customization and short production runs perhaps it is now time to rethink at least some of our manufacturing methods in case the product centred craftsman approach is the best and most cost effective solution.

While we do this we should also consider the merits of this issue's theme which is “Co-operative and two-arm robots”. Two robots working in harmony can be used to great effect and with great flexibility as they whittle away at our manufacturing challenges.

Clive Loughlin