This paper presents a multirobot cooperative event based localization scheme with improved bandwidth usage in a heterogeneous group of mobile robots. The proposed method relies on an agent based framework that defines the communications between robots and on an event based Extended Kalman Filter that performs the cooperative sensor fusion from local, global and relative sources.The event is generated when the pose error covariance exceeds a predefined limit. By this, the robots update the pose using the relative information available only when necessary, using less bandwidth and computational resources when compared to the time based methods, allowing bandwidth allocation for other tasks while extending battery life. The method is tested using a simulation platform developed in the programming language JAVA with a group of differential mobile robots represented by an agent in a JADE framework. The pose estimation performance, error covariance and number of messages exchanged in the communication are measured and used to compare the traditional time based approach with the proposed event based algorithm. Also, the compromise between the accuracy of the localization method and the bandwidth usage is analyzed for different event limits. A final experimental test with two SUMMIT XL robots is shown to validate the simulation results.
KEYWORDScooperative localization, cooperative sensor fusion, distributed kalman filtering, event based communication, event based estimation, mobile robots ities, which can produce great uncertainty in the pose estimation if not taken into account.A single robot can estimate its pose using sensors with Local information (encoders, gyroscopes, etc.) via Dead Reckoning [1] with an unbounded estimation error growth over time [2], or with Global information (GPS, zenithal camera, etc.) with direct pose measurement but slow response time and limited environment applicability