Reducing the Threat to Public Safety: Improved metallic object characterisation, location and detection

The United Nations (UN) have announced that "With more than 30,000 foreign terrorist fighters from some 100 countries around the world, terrorism is a global threat requiring a comprehensive and unified response." This statement followed a spate of recent terrorist attacks, including those in France and Germany (July 2016), and a growing sense of global uncertainty in the western world. Promoting improvements to the identification and location of metallic threat items is an important aspect of the unified response and is an area where engineering and science can make a significant impact. Improvements in metal detection (MD) technology also provides wider benefits to the humanitarian cause of clearing landmines in developing countries. Wider benefits exist for the technology being transferred to MD companies developing devices for the non-destructive testing (NDT) of materials for safe structures, ensuring food safety, improved scrap metal sorting, as well as in medical imaging and archaeological searches.

Of course current metal detectors do find highly conductive objects and their simple design (and portability) has made them a highly cost effective modality for safety and security applications. Unfortunately, current technology is not able (or has limited capability) to distinguish between objects of different shape and materials of objects and can only detect objects within a small stand-off distance (or buried depth).

This proposal is aimed at overcoming these drawbacks through an interdisciplinary approach to improving MD technology, combing engineering, mathematics and scientific computation. Our hypothesis is that the response of metallic items in low frequency electromagnetic fields can be accurately described using a tensor based approximation. To test this hypothesis, we will develop a complete laboratory demonstration of our MD approach. This includes the following novel aspects: an efficient and adaptable software that can compute tensor coefficients for in-homogeneous objects, an algorithm for identifying different targets from field measurements with embedded uncertainty quantification as well as enhancing MD measurements by building new coil arrays based on optimised coil design. The goal is that our complete software and measurement package will lead to a step change in MD.

The potential benefit of this research can be grouped as leading to societal, knowledge, people and economic Impacts and are closely interwoven with EPSRC's ambitions of achieving productive and resilient nations leading to UK prosperity. Societal and economic benefits stem from the improved identification of threat objects through the improvements to metal detection that we will develop. There has been a spate of recent terrorist attacks in France and in Germany and a result the UK threat level has remained as severe, implying that a terrorist attack is likely. Early identification of threat objects may help prevent future attacks.

The eradication of landmines in the developing countries also presents a huge challenge and the Find a Better Way (FABW) charity supported by charitable and government donations was established to aid the development of new technology to assist the clearance of the 1M active mines have clear societal benefits in the developing world as well as in areas of former conflict such as the Falkland Islands.

The UK generates 177M tonnes of waste each year much of which could potentially be recycled. The UK target is to recycle 76% of steel and 52% of aluminum in 2016 with targets set to grow in coming years. There are considerable economic benefits to be had from developing better scrap sorting processes based on improved metal characterisation that will result from our research and this can help reduce wasted resources (Typical recycled prices: aluminum £0.60/kg, stainless steel £0.90-0.75/kg, copper £3.10-3.60/kg).

In 2015, 1,514 food contamination incidents were reported by the Food Standards Authority in the UK. Many of these were associated with contamination resulting from bolts, nuts and wires displaced while food passing through the production line. Improvements in metal detection in the growing climate of mechanized food production will lead to both UK societal benefits (improved quality of life) and reduced potential legal action against food production companies (economic impact).

In this proposal we will work closely with our project partners (DSTL, Rapiscan and Safeline) and representatives from the Clearance of Landmines and Explosives (CIRCLE) and FABW to ensure rapid impact in all these areas.