Calibration and interface of a polaroid ultrasonic sensor for mobile robots

Abstract Ultrasonic range-finders, referred also as sonars, are known as robust and cheap distance measurement devices suitable for various applications including gathering of information from environment for real-world modeling as well as for navigating in mobile robotics. The ultrasonic range finders, based on POLAROID ranging modules, are the most widely found in mobile robotics literature. These ultrasonic ranging systems are low cost and their parameters satisfy the requirements of the most applications in mobile robotics. In this paper, a calibration model of an ultrasonic range-finder from a POLAROID ultrasonic ranging system is presented. It is built based on the experimental results. The calibration model includes: (1) probability directional diagram of the sensor and (2) probability estimation of the sensor measurements. An interface, which enables an external microprocessor system to read correctly the information from a POLAROID ultrasonic ranging system, is presented as well. In accordance with the accomplished research, an implementation of the developed means in mobile robot map building is described.