IR-UWB 레이더를 이용한 3차원 위치 측위에 관한 연구

Abstract

Nowadays, researches on locating systems have been actively conducted in various fields such as security, military and smart devices. A typical system used in smart devices and automobiles is Global Positioning System (GPS). This system finds a destination based on signals from satellites. In an emergency, one can also communicate one’s position so that others can respond. However, GPS has its weak points. With GPS it is not possible to track location indoors, and if a disturbance occurs, it is difficult to detect the object again. Ultrasonic sensors, cameras and infrared sensors are typically used to detect objects. But since these sensors are highly affected by their surrounding environment, there are many errors caused by the environment, and detection distance is very limited. This paper uses IR-UWB to detect objects. The IR-UWB radar system radiates regular impulse signals from TX antennas and checks the times to receive the impulse signals that are reflected from the target to measure the Time of arrival (TOA). It has low power consumption and high energy efficiency, and has a very wide spectrum band. To remove unwanted signals, the average value of the Raw-data is removed and a band-pass filter is used. The coordinates of the target is found by measuring the distance values. Two distance values (X, Y) are required to find two dimensional coordinates. Three distance values (X, Y, Z), using the Pythagorean theorem, are required to find three dimensional coordinates. This is called Trilateration. The experimental results in this paper had ranging errors of 3~10cm. These errors were caused by the process of moving one radar to each position. The results confirm that three dimensional coordinate measurement using IR-UWB is possible.