Development of a relative localization scheme for ground-aerial multi-robot systems

In this paper we demonstrate a design and experimentation of a relative localization solution for a multi robot team involving both ground and aerial robots. The relative localization method proposed in this paper has the ability to localize a dynamic agent with respect to only one leader ground robot in a GPS denied environment. The sensor solution proposed in the study employs a combination of an acoustic sensor and an infra-red(IR) based vision sensor for relative range and bearing estimations respectively. An extended Kalman filter performs the sensor fusion using a four degree of freedom kinematic model. Numerical simulations validate the sensor fusion scheme for both ground and aerial robotic relative localization. An experimental test-bed of the system with the hardware implementation of the sensors were developed. For comparison purposes the self localization modules of the robots are further integrated into the experimental setup. Realtime experiments were performed where 5-10 cm mean accuracy of pose estimation was achieved in multiple experiments.