Technology: Skin-deep intelligence for the fighter of the future

日期:2019-02-28 04:11:10 作者:袁嗣嚆 阅读:

AMERICAN aerospace companies, the US Air Force, and NASA are pushing for the development of ‘smart structures’ to improve the performance of military aeroplanes and spacecraft. The goal is a ‘smart aerospace vehicle’ which is sufficiently intelligent for the pilot simply to tell it where he wants to go and when he wants to get there. A computer on board monitors the condition of the plane and instructs ground crews about repairs. Internal sensors made from optical fibres could work while the vehicle is in flight, detecting, for example, stresses in components made from plastic composite materials, and relay that data to a central computer. Aerospace engineers would find these particularly suitable for the plastic composite materials that will be used in future vehicles. Similar technology might turn the vehicle’s ‘skin’ into a radar antenna or a communication artery. Eventually, electronic weapons may also be embedded in the structural material. Manufacturers already insert glass or carbon fibres into a plastic matrix to strengthen the composite. Fibre optic sensors can also fit into the matrix. Optical fibre made from glass is the most likely type of sensor because it does not carry electrical current; although small and light, it can withstand the effects of chemicals and temperatures encountered in the manufacture of most composites. The first uses for the technology are likely to be in controlling manufacturing. Conventional electronic sensors cannot monitor internal conditions of plastics, for example, which are strong only if properly cured. Fibre-optic sensors threaded through a composite can monitor temperature and chemical conditions inside the material. A device developed by McDonnell Douglas Astronautics in California detects hardening of the plastic material. This hardening causes tiny bends to form in the optic fibres and the detector can measure the amount of light that is lost when it passes through the material. Another detector from Simmonds Precision in Vermont measures fluorescence which varies as the hardening changes the plastic’s refractive index. Eric Udd of McDonnell Douglas believes the next step is to use embedded sensors to check the ‘health’ of a vehicle before it takes off. At the moment, flight crews now perform exhaustive tests of the space shuttle before launch, and fighter aircraft have strain gauges glued to vital components. The USAF is also interested in using the technology to measure the damage its planes sustain in combat. When on-board computers become available to aid pilots, smart structures could provide real-time data. They could warn of excess strain or icing on wings. Little is being said about the use of similar technology for communications, radar systems, and electronic warfare. Fibre-optic systems appear attractive because they are immune to electromagnetic interference and jamming,