An Inertial Navigation System for Autonomous Outdoor Robots

Abstract

Advances in MEMS technology have given rise to low-cost Inertial Measurement Units (IMU) that are key to many navigation applications. Due to common challenges in IMUs (e.g. scale-factor/bias stability, noise, etc.), often Inertial Navigation Systems (INS) are combined with additional sensors and estimation algorithms for corrections and drift mitigation. As the systems become more sophisticated, development and practical implementations become increasingly challenging. In this paper, we present a preliminary framework for the design of an aided INS on a Field Programmable Gate Array (FPGA) suitable for outdoor robotic applications. Such a framework will provide a flexible and hardware reconfigurable solution that is efficient. To further enhance the design process, a simulation environment is presented to assist in the development and testing of the entire system preceding migration to real-time hardware. A certain level of parallelism is maintained in the development of the code for the simulation and for the FPGA to provide a more realistic representation of the actual system and to improve on the implementation. Within this simulation environment, a measure of system observability is used to quantitatively characterize the benefit of the aiding sensors during GPS dropouts.