Method of determining range data in a time-of-flight ranging system

Abstract

A time-of-flight range sensing system for a vehicle such as a mobile robot comprised of a number of sensors that are situated at preset locations and aligned with particular orientations on the vehicle. Each sensor may consist of single or multiple transmitting transducers and single or multiple receiving transducers. Each sensor provides a means for changing the effective sensing volume of the sensors or it has two or more separate processing channels for processing the time-of-flight information with several different effective sensing volumes using the sensor signal processor. The sensor signal processor also provides a means for collecting information regarding the echo signal peak value and the noise present in the received signal before reception of the first echo. A sensor array processor excites the transducers, measures the time-of-flight of arrival of the first echo above a predetermined threshold and combines the data from the multiple signal processing channels so as to increase the range data gathering speed and to improve the fidelity of the range data received. The sensor array processor determines from the range data received and the signal and noise information the position and orientation of gross geometric features in the environment (flat surfaces, posts inside corners and outside corners) relative to the sensor array. This information may be used by a navigation control processor to avoid collisions, recognize features in the environment, or map the environment.

Dependencies are inferred from the claim text.