2getthere’s vehicles use virtual routes, defined in software. Vehicles follow the routes by continuously calculating their position relative to their origin. The distance is measured by counting the number of wheel revolutions, while direction of travel is measured via the steering angle and the information from a gyro.
The position is calibrated using external reference points. These reference points are simple, passive magnets embedded in the road surface. The small cylindrical magnets are spaced 2 meters and ensure the accuracy is within 2 centimeters on straight sections.
Each vehicle has a Vehicle Control System (VCS). The VCS communicates with subsystems dedicated to control or messaging tasks according to a master-servant relationship. The subsystems operate as independently as possible, enabling exchange without high impact.
The guidance control system (GCS) is a component of the VCS. It keeps an up-to- date estimation of the current position and generates set-points for steering, driving, and braking. These are based on a given target destination, its current position, and a definition of predefined paths.
To continuously calculate the position of the vehicle, the navigation software needs to know the steering angle, the wheel revolutions and orientation of the vehicle. For redundancy multiple wheel revolution sensors, steering angle sensors and orientation sensors are mounted to both the driven and steered wheels.
The patented Magnet Measurement System (MMS) is installed to detect reference markers (magnets embedded in the road surface) to calibrate the calculated vehicle position. The MMS in mounted behind the front wheels and is able to detect magnets over its full width.
The main benefit of the Free Ranging On Grid navigation technology is that physical guidance (such as rail or cable) is avoided, considerably reducing the infrastructure costs of the system. The technology is the most robust navigation technology as it avoids having to depend on line-of-sight to ensure its position on the track.