End Effector Development for Automated Sandwich Assembly

The food industry is the largest manufacturing sector in the EU, with an annual turnover of €836 billion. The are 290,000 food manufacturing sites spread across the EU and these employ a total of some 3.8 million people. The European farming industry sells a large proportion of its produce to food manufacturers. This, along with the sophisticated distribution network further adds to the number of people who rely on the food industry for employment. As a result of its vast size the food industry has been identified as a major growth area for the application of automation systems. However, unlike the more traditional manufacturing sectors food products vary enormously, both in ingredients and more crucially between different examples of the same product. This makes producing automated systems to handle food products extremely difficult and as a result less automation is found in the food industry than in many other sectors. The level of automation found in food factories varies enormously, ranging from completely manual operations to the use of highly advanced technology. Typically food factories in the EU use a mix of both manual operators and some automated machinery. The continued use of manual operators is due in part to the investment policy of manufacturers operating in a low margin industry and in part due to the flexibility provided by human workers. The use of manual operators is particularly high for tasks that involve the handling and manipulation of food products. Automation on the other hand is typically found where products are homogeneous i.e. final packing. The majority of food products are non rigid meaning their characteristics change during handling, they also vary in texture, colour, shape and sizes. Humans are able adapt to this product variability with ease by using their senses, typically vision and touch, and through accumulated knowledge and experience of the behaviour of a particular product. The ingredients used in the production of triangular sandwiches are a good example of this. For example the amount a loaf of bread rises when baked is affected by weather conditions and the firmness of a tomato reduces continually after it is harvested. Due to this variability no single end-effector, or indeed end-effector technology, can handle all food substances. Typically custom designed grippers are needed for each new project. This paper considers the end-effectors required to automate the manufacture of sandwiches. The paper begins by analysing current sandwich production processes. This is then followed by descriptions of the design and implementation of three end effectors developed for use on an automated sandwich assembly line. Finally conclusions are presented. End Effector Development for Automated Sandwich Assembly