LAUSR

In this article, a model-based cooperative navigation system for a group of quadrotors, while no absolute position data is accessible, is proposed. The growth of position errors in a GNSS-denied condition is such that the navigation methods are not reliable. In the proposed method, instead of the conventional inertial navigation equations, a different dynamic equation based on drag forces is used. Together with the relative position measurements between agents, the acceleration measurements on the plane of the rotors of at least one of the agents are also used in the observation process. For evaluation of the proposed method, an algorithm-in-loop 6DOF simulation environment is developed. The results illustrate that the growth rate of navigation errors is significantly reduced; 97% in the horizontal plane and 40% in the vertical one. In short, integrating the proposed model-based and cooperative navigation methods is more effective than using each of them separately.