Loosely Coupled Integrated Navigation System for Excavators

On the way to autonomous excavators the knowledge of its position and attitude is necessary to fulfill planned tasks. The current position and attitude of the excavator is mandatory to approach specified positions and perform an excavation task, i.e., to control the excavator. The usage of an inertial measurement unit (IMU) and global navigation satellite system (GNSS) is a common choice to obtain estimates of the position and the attitude. In this paper a dual antenna real time kinematic (RTK) GNSS setup and an IMU on the upper structure of the excavator are integrated with a loosely coupled closed loop architecture. The measurements from the GNSS and the IMU are integrated with an error state Kalman filter and nonholonomic constraints on the excavator are considered. The performance is evaluated on an experimental excavator.