Low cost sensors data for parameters and trajectory determination

Several applications to determine a moving vehicle trajectory using inexpensive inertial sensors and GPS measurements are emerging. In such systems, a single gyroscope and a vehicle odometer instead of orthogonal set of three gyroscopes and accelerometers are preferred for low cost. Some important factors influencing the accuracy in such configuration are the presumption of the verticality of the gyroscopes, low resolution measurements affected from various environmental and vehicle dynamics, only longitudinal direction linear displacement measurements, residual errors in sensor parameters, etc. Occurrence of GPS data gaps and multi-path errors when driven in urban environment are also sources to make the results unreliable even from integration using Kalman filtering method. Among other, one most important measure to overcome these problems is to determine the parameters with highest accuracy possible. A method called Adaptive Trajectory Segmentation (ATS) has been developed to derive data and use them to determine the parameters easily, accurately and more frequently. Details of this process together with different methods for parameters determination are presented in this paper with some results to illustrate the effectiveness of the methods.