Implementation and performance evaluation of an inertial navigation system/global navigation satellite system real‐time kinematic Ntrip navigation system aided by a robot operating system‐based emulated odometer for high‐accuracy land vehicle navigation in urban environments

Abstract

AbstractAdvanced land‐vehicle navigation commonly uses integrated systems to counteract global navigation satellite system (GNSS) solution degradation. This occurs mainly in urban environments due to blockage of the satellite signals. This paper presents a loosely coupled inertial navigation system/GNSS navigation system that combines an attitude and heading reference system (AHRS) device with a dual‐frequency dual‐antenna GNSS heading receiver. The integrated navigation system is aided by a low‐cost odometer which replaces external wheel speed sensors usually installed in autonomous vehicles. The proposed odometer extracts the anti‐lock braking system‐generated pulses of rear wheels from vehicle controller area network messages. Following, it converts them into software‐generated signal pulses which are sent to the AHRS device through the serial port. The system platform uses a mobile internet data link to get differential GNSS corrections in real‐time from a public Ntrip—networked transport of Radio Technical Commission for Maritime Services via internet protocol—broadcaster in order to allow the GNSS receiver to operate in differential global positioning system/real‐time kinematic (RTK) modes. Thus, the integrated navigation system provides centimeter‐level positioning accuracy at 100 Hz. Since the positioning accuracy is severely affected by numerous factors, this work proposes a replicated 24 full factorial design with the purpose of evaluating the in‐field obtained positioning performance under different factors combinations. The experimental design chosen allows to know under which conditions it is feasible to replace the available GNSS velocity by the proposed odometry solution, when they are used as navigation aids, and knowing that the proposed odometry has a low resolution. The analysis of 32‐runs factorial design results, using a significance level of .05, demonstrated that the proposed odometry can overcome GNSS/RTK velocity.