Advanced ultrasound object detection in air by intensive use of side lobes of transducer radiation pattern

Abstract

In this paper correlation techniques are discussed to extend the measurement range of an ultrasonic transducer to its side lobes. Broadband coded signals (linear chirps) are used to steer the transducer's radiation pattern. The presented method allows to extend the angle range of the transducer beyond the main lobe for distance measurements and delivers additional information about the angle from the transmitter to the reflecting object.

An accurate compact ultrasonic 3D sensor using broadband impulses requiring no initial calibration

“…20]. If using correlative methods the usage of different templates [19,8] is necessary because of the different impulse response depending on the polar angle. For example see Fig.…”

“…These systems have been improved for more reliability by transducer modeling and by including acoustic propagation and reflection properties in their models [6]. Recently systems have been reported which can obtain 3D position information using only a single sensor [7,8]. In systems employing more than one receiver the binaural configuration is the most common one.…”

“…This work has evolved from two different sensor configurations developed at our group. The sensor presented in [8] uses a broadband ultrasonic transducer with a frequency dependent radiation pattern. This results in a change of phase and amplitude of the perceived signal depending on the direction relative to the transmitter main axis.…”

Digital signal processing in ultrasonic based navigation system for mobile robots

“…• optical markers and automatic vision systems [9][10][11][12][13], • distance measuring transducers (odometry) [4], • onboard accelerometers, gyroscopes, compasses [14][15][16][17], • noncontact distance measuring devices using: radar waves, infrared light, lasers (LIDARs) or ultrasonic waves [18][19][20][21][22][23][24][25].…”

“…Advanced methods of modulating the emitted ultrasound packet and algorithms of processing of received waveforms have been developed [19,20,22,25]. They allow to precisely calculate the distance and direction of arrival of the wave.…”