Angle-of-Arrival Analysis of Multi-channel Stereo Ultrasonic Signal for Angular Coordinates Positioning

Angular coordinates system requires output from precisely angle measurement to calculate the final coordinates result correctly. Generally, acoustic direction measurement sensors are designed in a pair of sensor or in an array of sensors. To obtain the result, the system must process each pair of stereo signal to find the relationship between left and right channel to find the actual source direction. This procedure is also called Acoustic Angle-of-Arrival (AOA) Analysis. This paper presents an applied Cross-correlation technique of multi-channel stereo ultrasonic signal to achieve the comprehensive horizontal plane AOA result. Factors considered in the solution included precision of direction measurement in each stereo pair and the result after integration. The model building and its efficiency testing indicated that the result after the integration can reach high accuracy rate with an average error rate at 2.65 degrees cover any direction in horizontal plane, and the RMSE at 4.07.