Using MEMS Sensors to Enhance Positioning When the GPS Signal Disappears

This paper presents the concept of using embedded MEMS sensors position objects especially when the GPS signal is weak, e.g. in underground car parks, tunnels. Such an approach is important for controlling indoor objects or autonomous vehicles. The signals are acquired by a Raspberry Pi platform with external sensors such as an accelerometer, gyroscope and magnetometer. A self-propelled vehicle was used and several exemplary paths were designed for acquiring signals. It was proven that appropriate signal filtering allows a position to be determined with a small error at a constant velocity condition. Comparing filters such as the moving average, median, Savitzky-Golay and Hampel filters were investigated. Moreover, the system offers a high degree of accuracy in a short time for indoor hybrid positioning systems that also have video processing capabilities. The cyber-physical system can also be used with the existing infrastructure in a building, such as Wi-Fi access points and video cameras.