Trajectory tracking of an oscillating movement with a low-cost IMU in geodetic surveying applications

In this paper, we design a method to use a low-cost IMU (Inertial Measurement Unit) sensor for the absolute positioning of an oscillating object and for improvement of the kinematic RTS (Robotic Total Station) high-precision trajectory tracking accuracy. Typically when using standard methods for position estimation based on IMU measurements, a drift of several hundred meters occurres after only 1 min of operation. When processing IMU measurements with our proposed method, which is based on the Zero-Phase filter (ZPF), the accuracy of the oscillating object’s position improved to a few centimeters. We used our method to improve the RTS trajectory tracking system. By combining low-cost IMU and RTS measurements, we were able to obtain highly accurate trajectory at a frequency of IMU measurements. We improved the accuracy of the trajectory tracking compared to linear interpolation between measured RTS samples by 40% and the SNR (Signal-to-Noise Ratio) was more than three times higher