GENERATION OF FOCAL REGIONS OF COMPLICATED CONFIGURATIONS USING 2-D PHASED ARRAYS: POSSIBLE FIELDS OF PRACTICAL APPLICATIONS

In the last years, new methods for robotics, sensors and automated control systems based, in particular, on the use of tactile sensations in the human-machine interface are actively developed. One of the perspective directions of investigations is the development of tactile displays intended for transfer of touch information to a person using the acoustic method based on the radiation pressure effect. In practice, it is necessary to synthesize with high speed on such the display different patterns (symbols, letters, numbers, etc.), sometimes of complicated configuration. It is shown that it is possible to create such patterns by synthesizing multiple foci using two-dimensional phased arrays with random distribution of elements over the array surface. The parameters of such random array are presented. It is shown, that random arrays allow creating the regions of action of focused ultrasound of various required shapes and configurations with the intensity levels in the grating lobes and other secondary maxima of the intensity which are appropriate for the practical applications. With the use of these arrays, it is possible to steer the multiple foci off the array axis at the distance equal to, at least, ± 5 mm. On the screen of the tactile display, it is possible to generate regions of action of rather complicated configuration, for example, letters of the Latin alphabet, etc. Such the opportunity can be of interest for the development of devices allowing blind persons, using touch sense, to perceive textual information presented on the display.