Strategy of Finding the Travelable Area for Autonomous Mobile Robot Using Distance and Integration Value Obtained By Ultrasonic Wave Sensor

The ultrasonic TOF (Time-of-flight) ranging system is today the most common sensing system employed in indoor mobile robotic systems, primary due to the ready availability of low-cost systems, their small size, simple circuits, and their ease of interfacing with computers. TOF ranging systems measure the round-trip time required for a pulse of emitted energy to travel to a reflecting object, then echo back to a receiver. However, ultrasonic TOF ranging systems tend to neglect minute reflected waves below the threshold level. In this paper, we propose a novel approach to utilize the minute reflected waves by integrating the reflected waves. It is implemented using a transducer with scanning system, and has a great ability of finding the travelable area for a robot in environments in which the distance cannot be obtained precisely. The proposed system is constructed by simple way so as to improve the utility value of sonar. The validity of the proposed method is investigated by applying this method to autonomous mobile robot in various environments such as environment with multiple obstacles, in the end of the hall, and so on.