Optical azimuth sensor for indoor mobile robot navigation

A new type of azimuth angular sensor for an indoor mobile robot navigation is developed. This is a kind of optical sensors using infrared linear polarization. Since an angle is measured without contact, it is applicable to the navigation of an autonomous mobile robot. In the indoor environment, the navigation system by using GPS cannot be used. In dead reckoning, the accumulation of measurement error occurs a serious problem. If we use this sensor, we can measure a position only by installing one landmark all over the working space. We can acquire simultaneously not only the distance from a landmark but an angle of direction. Like a gyroscope or a geomagnetism sensor, the large drift depending on environment or time does not occur by this sensor. We make a prototype of the sensor based on this technique and conduct the measurement experiment. The accuracy of azimuth angle error is about 4% and the radial error is 93(mm) at 3(m) distance from the landmark.