Autonomous robots and vehicles need to be able to navigate their surroundings with high accuracy, safety, and continuity. This means they must have continuous access to a reliable position and navigation solution. Satellite navigation systems (e.g. GPS) are the standard source of position data outdoors, but such systems are sensitive to interference due to weak signal strength. In addition, satellite navigation systems do not work indoors. Alternative sources of position are therefore needed to be able to guarantee such systems. Phased-array radio system (PARS) is a possible alternative positioning source.
In this project, together with partners Nordic Semiconductors, AutoStore and Zeabuz, NTNU will research and test solutions where autonomous robots and vessels are positioned with PARS. Zeabuz is a spinoff company from NTNU that develops solutions for autonomous passenger ferries. AutoStore supplies solutions for fully automated warehouses. Nordic Semiconductor develop integrated circuits for use in wireless technology.
The project's main purpose is: To investigate reliable positioning and navigation solutions based on PARS modules. Central planned activities are:
- Use commercially available low-cost radio modules that support direction and distance determination to estimate the position of robots and vehicles.
- Study and analyze PARS and environmental disturbances in relevant scenarios for the partners and research methodologies that prevent such errors and error sources from negatively affecting the positioning.
- Use sensor fusion with other sensors to improve the integrity and reliability of the radio positioning systems.
- Deploy and use the solutions in relevant environments and areas of use for the project partners. For example, docking of autonomous passenger ferries, automatic landing of drones and monitoring of robots in autonomous warehouses.
Although Global Navigation Satellite Systems (GNSS) have a global coverage, there are many so-called GNSS-denied environments where GNSS is not available, is degraded, or unreliable due to signal blockage, electromagnetic interference, or cyber-security threats such as jamming and spoofing. These include indoor environments, urban areas, industrial sites, and battlefields. There is a clear need and strong business case for alternative technologies that can replace or complement GNSS in such cases. Many applications of autonomous systems, service robotics, and localization and tracking of assets are currently limited by this technology gap and concerns related to the security and vulnerability of GNSS.
This project will therefore develop improved algorithms and systems for resilient localization and navigation without GNSS, by instead using phased-array radio systems (PARS). A typical setup consists of a radio system with multiple antennas assembled in an array at a fixed location, and a single antenna radio on the node that shall be localized. The direction of arrival or departure of radio signals can be computed from measured phase differences of the signals from the different antennas arranged in the array. In this project, we will investigate PARS based on low-cost and open COTS technologies, primarily Bluetooth antenna arrays. We will also reap the benefits of multi- sensor fusion with inertial navigation and other aiding sensors such as altimeters and lidars in some navigation applications. The developments will be tested and validated in selected environments, together with industrial partners (Nordic Semiconductor, Zeabuz and AutoStore). These use cases include automatic docking of urban ferries, automatic landing of multi-rotor drones on small ships, automatic recovery of fixed-wing unmanned aerial vehicles in the field, and tracking of autonomous warehouse robots.