A tracking sonar sensor for vehicle guidance

A sonar sensor capable of focus of attention which tracks environment features moving with relative angular velocities up to 0.6 rad/s and linear speeds up to 2.4 m/s is described. The sonar uses a monopulse arrangement of a single transmitter and spaced receiver pair to provide both range and differential target bearing information. The monopulse arrangement is mounted on a high-speed servo which is used to null the monopulse signal and continuously aim the sonar at the center of a region of constant depth. It is shown that the sensor can provide accurate and reliable relative location information for a platform moving at speed through typical indoor environments. The implementation of a localization algorithm which uses this information to enable the device to act as a stand-alone guidance sensor for an associated mobile platform is described