Attitude Observers for Accelerated Vehicles Without Accelerometer Measurements

In this paper, we present two nonlinear attitude observers for accelerated vehicles moving in 3-D space using a global positioning system, a gyroscope and a magnetometer. These observers are developed based on the idea that for highly dynamic motions, the acceleration or the error affecting acceleration can be strongly related to dynamic changes in velocity errors. The observer error signals are converged to zero in very short time and for any almost initial conditions. Conditions are given to guarantee the asymptotic stability of the system. Simulation results have proven the best performance of the proposed observers compared to results obtained by other observers recently developed in the literature.