Distributed Cooperative Localization Based on Bearing-Only Sensors

We consider a distributed cooperative localization (CL) algorithm for a group of mobile robots in GPS-denied environments. Each robot is equipped with IMU and optical cameras. Using the CL method, mobile robots in a group achieve stable self-localization by communicating and processing interrobot relative measurements with sparse absolute positioning information such as a few identifiable landmarks. This paper provides a fully-distributed algorithm for bearing-only cooperative localization in a form of stepwise update, in which each agent plays as both the observer and the observed to update its states in two steps. It’s an iterative algorithm that requires less memory, and does not need all-to-all communication. In the proposed method, the covariance intersection (CI) is generalized to a bearing measurement model and it can be applied in switching topology. The simulation result shows the feasibility of the present method.