Three Different Approaches for Localization in a Corridor Environment by Means of an Ultrasonic Wide Beam

Abstract

In this paper the authors present three methods to detect the position and orientation of an observer, such as a mobile robot, with respect to a corridor wall. They use an inexpensive sensor to spread a wide ultrasonic beam. The sensor is rotated by means of an accurate servomotor in order to propagate ultrasonic waves towards a regular wall. Whatever the wall material may be the scanning surface appears to be an acoustic reflector as a consequence of low air impedance. The realized device is able to give distance information in each motor position and thus permits the derivation of a set of points as a ray trace-scanner. The dataset contains points lying on a circular arc and relating to strong returns. Three different approaches are herein considered to estimate both the slope of the wall and its minimum distance from the sensor. Slope and perpendicular distance are the parameters of a target plane, which may be calculated in each observer's position to predict its new location. Experimental tests and simulations are shown and discussed by scanning from different stationary locations. They allow the appreciation of the effectiveness of the proposed approaches.

New Methods for Robotic Perception by Using in-Air Sonar Data

“…The sonar sensor array used in all the tests is described in [4][5][6][7][8][9][10][11] and is reproduced here for clarity. It is composed of two types of ultrasonic sensors: the Hagisonic AniBat HG-M40DAI and the HG-M40DNI [12].…”

“…The same sensor array has also been used for evaluating the orientation of a wall; in this case, the tripod has been rotated in such a way that the array rotation axis z is perpendicular to the xy plane to obtain a right-handed orientation (as in Figure 2). All the technical details of the electronic boards that were realized -the sensor electrical connections and rectangular driving signal generation with a frequency of 12.5 Hz, the duty cycle of 4% and the amplitude of 4 V -are fully described in [4][5][6][7][8][9][10][11]. The TOF is estimated by the period that elapsed from the rising edge of the input pulse to the rising edge of the output pulse, while all the output signals were acquired by the acquisition board NI-USB 6210 [14].…”

“…The authors dealt with this problem by developing and testing algorithms for obstacle detection and reconstruction using in-air sonar sensors [4][5][6][7][8][9][10][11]. The present article involves recently published studies and summarizes all the significant findings in a unique contribution.…”

“…They realized an array of four ultrasonic sensors moved by a digital modular actuator [4] and utilized it to scan corners, planes, corridors and rooms [4][5][6][7][8][9][10][11]; the reconstruction algorithms used the digital sonic signals and the analogue full-waveforms. Moreover, they carefully examined the physical phenomenon of multiple reflections in the zone close to the intersection, introducing new reconstruction strategies based on powerful mathematical tools, such as Fuzzy C-Means (FCM) algorithm [4][5][6][7][8][9][10][11], RANdom SAmple Consensus (RANSAC) fitting [4][5][6]9], Principal Component Analysis (PCA) [7][8]9,11] and a function inspired by the Gibbs entropy [10].…”

“…Moreover, they carefully examined the physical phenomenon of multiple reflections in the zone close to the intersection, introducing new reconstruction strategies based on powerful mathematical tools, such as Fuzzy C-Means (FCM) algorithm [4][5][6][7][8][9][10][11], RANdom SAmple Consensus (RANSAC) fitting [4][5][6]9], Principal Component Analysis (PCA) [7][8]9,11] and a function inspired by the Gibbs entropy [10].…”