Localization and Place Recognition Using an Ultra-Wide Band (UWB) Radar

This paper presents an approach to mobile robot localization, place recognition and loop closure using a monostatic ultra-wide band (UWB) radar system. The UWB radar is a time-of-flight based range measurement sensor that transmits short pulses and receives reflected waves from objects in the environment. The resulting echo waveform is the sum of the reflected waves, and the delay of each component reflected wave depends on the distance between the sensor and the object. Consequently, the received waveform is a superposition of individual echoes that depend on ranging distance, material, shape and radar reflectance of the obstacles in the environment. The echo waveform measured by the UWB radar has more information than what can be provided by an optical sensor of comparable range, as it provides data from inside and beyond obstacles. At the same time, the sensor data is consistent and repeatable for a given location and a static environment. This paper proposes a waveform matching method for place recognition, presents a number of experiments that illustrate the high position estimation accuracy of our UWB radarbased localization system, and shows the resulting loop detection performance in a typical indoor office environment and forest.