Ultrasound reflection tomography for industrial processes

Abstract The use of ultrasound reflection mode tomography has mainly been investigated with a reduced number of transducers, often just two. In a typical configuration one sensor is stationary while a second sensor is rotated around a circular arc taking a number of tomographic measurements which are used to reconstruct an image. While this arrangement allows measurements to be made from a large number of positions around an object (sometimes over 100 positions), it is not fast enough to provide the real-time information which is required by many industrial processes. This work describes an ultrasound reflection mode system with a circular array of 36 transducers that is able to generate reconstructed images at an average of 30 frames per second. To achieve this speed of image reconstruction an intensive use of processing resources is required. A parallel processor array is employed for the reconstruction of the image frames and the data acquisition is assisted by a dedicated digital signal processor (DSP). The results obtained by this system in the form of images of test objects, with a resolution of 100 × 100 pixels, show that reasonably good results can be obtained with ultrasonic tomography systems in the explored configuration.