The aim of this project is to develop, for leather shoe upper parts, an automated lay planning system which will be interfaced to manual cutting system and offers scope for linking to numerically controlled cutting systems. It will be computer-based, targeted specifically at the requirements of SMEs and aimed to cope with their typical product mix, shoe order quantities, size distributions and range of materials. The project is particularly relevant to the SMEs. It brings pre-planning and computer technology into the traditional area of leather cutting. The benefits of a successful conclusion to this project will be a reduction in manufacturing costs through improved material utilisation. Better productivity through shorter training periods for operatives and an improved man/machine interface through modernisation of the workplace. The approach will also lead to improved consistency of product by enhancing the skills of poorer operatives. Upper leather accounts for up to 40% of the cost of a shoe and a substantial proportion of the leather skin ends up as waste on the cutting room floor. It is an expensive material and a small improvement in the utilisation of the material can make a large improvement in the overall profitability of a footwear manufacturer. Traditional leathercutting is a manual process involving a hand positioned knife and a press. There is no pre-planning before cutting and the results are dependent on the skill of the operative. In this project we are proposing a means of automatically laying out and interlocking complex pattern pieces with varied requirements onto a leather skin; giving consideration to the size and shape of the skin, its directional properties and any flaws in the leather. The main innovation lies in the proposed use of fuzzy logic controlled computer based methods of grouping components in a similar way to manual methods attempted by the best cutting operatives, taking into account the relevant direction, quality and production constraints. Unlike traditional methods, the complete lay can be planned before a single cut is made, thus adding flexibility. Furthermore, a target yield calculation will be generated to judge each lay plan before proceeding with cutting. Apart from guidance and control of leather cutting to achieve improved utilisation of materials, it is envisaged that the computer-based system will be a powerful training aid which will reduce both training times and variations between individual cutting operatives through raising the standard of the poorer ones by using technology to enhance human skills. The lay plans that are produced can be used in a variety of ways. For manual cutting, a paper print-out, screen display or projected image may be used as a guide for achieving good material utilisation. For numerically controlled cutting, each lay plan may be developed into a cut file and input to a variety of machines.
Funding SchemeCRS - Cooperative research contracts
3700-018 S.joao Da Madeira
3700 121 S.joao Da Madeira
BB1 1TZ Blackburn
NN16 9JH Kettering