Speed control of a sonar-based mobile robot with considering the self-localization

The ultrasonic TOF (time-of-flight) ranging system is the most common sensing system employed in indoor mobile robotic systems, primarily due to the easy availability of low-cost systems, their compact size, simple circuits, and their ease in interfacing with computers. However, ultrasonic TOF ranging systems tend to neglect infinitesimal reflected waves below the threshold level. We have proposed a new approach to utilize the infinitesimal reflected waves by integrating the reflected waves. This is implemented using a transducer with a scanning system, and has a great ability of obtaining the travelable area for a robot in environments in which the distance cannot be precisely measured. However, it is very difficult for this sensing system to resolve more higher task such as navigation problem or global map generation because it uses only local information. This paper introduces gyroscope sensor in addition to sonar and PSD, and perform self-localization. The validity of the proposed method is investigated by applying this method to an autonomous mobile robot in various environments such as one with multiple obstacles, at the end of the hall, and so on.