Unmanned Systems Technology 006 | ECA Inspector Mk2 USV | Antenna systems | Northwest UAV NW-44 | Unmanned ground vehicles | Navigation systems | Lunar X challenge

58 Insight | Unmanned ground vehicles Mass transport Transport of all kinds is the application with the biggest potential for unmanned ground vehicles, but there are many different approaches to implementing systems, from mass-transit pods to driverless trucks and cars. “Google found that autonomous operation needs a separate development process,” says Prof Nick Reed at the UK’s Transport Research Laboratory (TRL). Along with several other companies such as Navya and 2getthere, Google has been developing ‘pods’ that have no user controls in them, and operating them in restricted areas. The development process is then to expand the environments the pods can operate in, rather than the technology, he says. Autonomous pods such as the those in the GATEway project and Lutz Pathfinder programme in London and Milton Keynes, UK, respectively, and the WEpod in Gelderland, in the Netherlands, have been focusing on level 4 autonomy (see figure), one step below full autonomous operation, and will be on public roads for the first time during 2016. The WEpod was designed by French manufacturer EasyMile for the Citymobil2 EU project, which has already transported more than 19,000 passengers in Vantaa, Finland, and Lausanne, Switzerland. Pods from French developer Navya have already transported 15,000 passengers over 10,000 km in 25 projects around the world. Automated mass-transit vehicles from Dutch systems maker 2getthere have been on the road for five years in the Dutch city of Masdar, carrying up to 43,000 passengers a month. The vehicles use routes defined in software that continuously calculates the pods’ position relative to their origin. The distance from the origin is measured by counting the number of wheel revolutions, while the direction of travel is measured via the steering angle and information from a gyroscope. Their position is calibrated using external reference points from passive magnets embedded in the road surface. The small cylindrical magnets are spaced 2 m apart and ensure a positional accuracy within 2 cm on straight sections of the route. The main benefit of this technology, called Free Ranging On Grid (FROG) navigation, is that it avoids the cost of physical guides such as rail or cables, and having to depend on line of sight to determine the vehicle’s position on the track. Each vehicle has a Vehicle Control System (VCS), which communicates with subsystems dedicated to control or messaging tasks in a master-slave architecture. The guidance control system (GCS) is a component of the VCS and keeps an estimate of the current position and generates set-points for steering, driving and braking. These set-points are based on a given target destination, its current position and a definition of predefined paths. To calculate the position of the vehicle February/March 2016 | Unmanned Systems Technology Levels of automation in unmanned ground vehicles Passive magnets embedded in the road ensure a positional accuracy of within 2 cm, and avoid the cost of physical guides such as cables