The Visual Navigation System improves navigation in GNSS-denied environments by means of visual odometry techniques
Photo: UAV Navigation
UAV Navigation has released its new Visual Navigation System (VNS), a new capability for manufacturers and end users of NATO Category I and II unmanned aerial systems (UAS).
The compact and lightweight device — provided as an optional peripheral to the main flight control system — enables the safe and efficient navigation of UAVs in GNSS-denied environments. The VNS combines visual odometry techniques and pattern identification with the rest of the sensors onboard the aircraft to ensure that the absolute position, orientation and relative movement of the aircraft over the ground is calculated with extremely high accuracy.
The planning and execution of UAV missions in environments in which the GNSS signal is either unavailable or unreliable is becoming more critical. For some missions, the datalink to the ground control station may be subject to interference, or the operation dictates that the flight must be performed without a datalink from the outset.
Under these circumstances, UAS traditionally rely on an inertial navigation system (INS) to complete the mission. However, all such inertial systems accumulate navigational drift due to sensor noise, propagation models and the difficulty in characterizing external forces. This positional error limits any such UAS operation because an accurate position cannot be guaranteed.
The new VNS, combined with the company’s Vector range of flight control systems, effectively addresses this problem by using data independent from GNSS and more accurate than INS. The system identifies patterns in the terrain below to assist in canceling out any accumulated error, allowing the UAS to operate for long periods without losing positional precision.
Because of its reduced size and weight, the VNS can be installed in Category I and II UAS, enabling them to take advantage of this navigation technique without penalizing autonomy or payload capacity.
The new VNS — developed entirely by the Spanish company UAV Navigation, part of the Oesía Group — has produced outstanding results during flight testing, both on fixed-wing platforms (typically with higher airspeeds and greater service ceilings) and rotary-wing platforms (where high vibrations and hover maneuvers are typically a problem). The new VNS has proved its ability to provide accurate navigation information for flights where there may be an intermittent loss of GNSS signal, and also when a flight must be executed from the outset without GNSS data.
Download the Visual Navigation System brochure here.