There are few test objects suitable for colour-flow ultrasound scanners. An acoustic injection device is described that enables the production of a 2-D region of colour on a colour-flow image. The device involves detection of the transmitted ultrasound pulse from the scanner, followed by the emissio
An acoustic sensor system for object recognition
β Scribed by M. Lach; H. Ermert
- Publisher
- Elsevier Science
- Year
- 1991
- Tongue
- English
- Weight
- 483 KB
- Volume
- 26
- Category
- Article
- ISSN
- 0924-4247
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β¦ Synopsis
Object identification with application to industrial manufacturing processes using acoustic means is an alternative method to optical sensing. A sensor system consisting of a pair of broad-band transducers operating at wavelengths of some millimeters in air can recognize objects with sizes up to 15 mm. Arranged in a side-looking position with respect to the objects, the transducer pair is moved across a linear aperture to give spatial and spectral information. The echo data are processed to calculate an angle-dependent spectrum which allows object displacements to take place. A pattern is generated which is invariant for object rotations of several degrees. During a teach-in procedure, data are collected from an ensemble of interesting objects. A small set of discrimination vectors is calculated using the Karhunen-Loeve expansion. Objects belonging to the ensemble are identified by a k-nearest-neighbour classifier.
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