Flight Control for Rotary Wing UAVs

Protection against sensor failure

A high level of safety is provided because the autopilot is designed from the beginning to be able to survive individual and even multiple sensor failures. The autopilot will continue to function correctly even if GPS or the magnetometer is lost. The autopilot will adapt the performance of the aircraft to the conditions to ensure the filght safety.

Online Hard Iron Calibration

The OLHIC algorithm ensures that the built-in magnetometer is constantly being monitored and calibrated during flight. This means that accumulated in-flight error due to magnetic drift is minimized.                                                                                     

Use of an integrated ADS

The use of a built-in Air Data System (ADS) allows the autopilot to fly according to airspeed instead of GPS speed; this results in a more efficient flight under all possible scenarios. Also, in case of GPS signal loss (dead reckoning) or magnetometer failure, the ADS allows the aircraft to continue the operation safely. Additionally, the ADS allows barometric altitude control.

Multiple gains settings

The autopilot can be loaded with more than one set of gains (i.e. 'gains banks'). This allows automatic interpolation of gains depending on airspeed. This capability guarantees the best possible control under all flight conditions.                                                                                                                                                                                                                                                                                           

Altitude protection                     

By taking advantage of readings from a radar or laser altimeter unit, the autopilot is able to maintain accurate height above ground, which can be critical for low altitude operations of hover manoeuvres where a precise height must be maintained.

Autorotation

UAV Navigation has developed a fully-functional and proven autorotation capability for helicopter UAV platforms. This highly advanced feature allows the autopilot to land the aircraft safely in case of a loss of engine power or tail rotor failure. A safe descent is performed, followed by a flare manoeuvre. UAV Navigation's VECTOR autopilot is one of very few autopilots to have a fully functional autorotation capability.

Since 2004 UAV Navigation has provided complete flight control solutions for all configurations and sizes of rotary wing platforms. Current clients include manufacturers of conventional helicopers, intermeshing blade designs, coaxials, tandem rotors and multirotor designs. The system is capable of controlling all size of rotary wing design, from small <20kg platforms up to the largest current helicopter which has an MTOW of 1,361kg (of course larger helicopters are possible). UAV Navigation autopilots can be used for many different platform types; the same hardware is used but different software is loaded.

UAV Navigation has developed an advanced Hardware In the Loop (HIL) simulator to minimize risk during the development phase of a project. Our engineers will develop a 6DOF model of the client's platform in order to produce a set of gains specifically tailored to its flight characteristics. If necessary any special requirements from the client can be developed at this stage (e.g. integration of a particular camera or other payload).

The autopilot takes care of all the basic tasks of flying the platform safely, including fully auto take-off and landing, Return-To-Base, multiple waypoints, hover etc. In addition to the basics, the autopilot can also interact with a wide variety of payloads, including complex gyro-stabilized gimbals (DST, UAV Vision, Octopus, etc.), transponders, laser altimeters, radar altimeters and laser designators for advanced functions such as geo-referenced pointing and target tracking.

Despite its small size UAV Navigation's product is a complete autopilot, meaning that the unit contains all of the sensors required to fly the helicopter; no extra sensors or boxes are required other than the servos to move the control surfaces.

Other Special Features for Rotary Wing Platforms

   Compact unit. No external sensors, Inertial Measurement Unit (IMU) or Mission Management Computer are required - they are integrated within the same box.

   Capable to fly similarly to a fixed wing platform. The autopilot takes account of the prevailing wind condition and controls the helicopter to follow the track whilst maintaining the most efficient profile, pointing the nose into the wind.

   Integrated governor. The autopilot features a built-in governor which is able to take readings directly from an RPM sensor. This allows the autopilot to manage engine power in order to maintain optimum RPM in all flight modes and phases of the mission. This function also allows the autopilot to manage completely automatic spool up of the rotor before take-off and also slow down before engine stop at the end of a mission. 

   Certified Hardware. The hardware is certified to MIL-STD-810F and MIL-STD 461F.

For the most demanding rotary wing applications where ultimate performance, reliability and connectivity are required, the VECTOR autopilot is the natural choice for the professional.