Robbe Helicommand Rigid V2
Many attempts have been made to build a stabilisation system for untethered helicopters. Existing control aids designed for models are either just a supplementary x-y gyro system, or a circuit based on simple light or infra-red sensors, which only work if the horizon is absolutely level, and there are no visual obstructions. Until now it has only been possible to provide genuine autonomous control at great expense whilst incurring considerable compromises. The unavoidable fact is that inclination measurement with gravitation is impossible when we are dealing with a helicopter; with conventional systems at least one GPS system has to be included in the on-board equipment if geographical stability is required. If a normal helicopter is left alone for just a few seconds, it quickly drifts off in an arbitrary direction, accelerating continuously - which means, it would not survive for long.
The Helicommand unit stabilises the helicopter's position as well as its attitude.
It incorporates a new form of ground sensing which works incomparably more accurately than a GPS system when at very low altitude, i.e. the helicopter's movements can be measured and corrected more finely. In contrast to GPS, the new process also works even when there are buildings or trees in the immediate vicinity, and in indoor locations - provided that the lighting conditions and contrast are adequate.
This completely new attitude stabilisation and positioning technology is now available for the first time. It was developed primarily for professional and industrial applications, but now includes a version specifically for modelling use. The system contains multiple control and measuring circuits which provide impressively reliable results.
Characteristics are not previously achieved quality of regulation, compact architecture and low weight, and all this for an affordable price.
- Dual independent instrument systems and sophisticated software for excellent reliability
- New type of sensing process provides stable positional monitoring, completely independently of the visible horizon
- Electronic triple-axis gyro with accurate attitude control and artificial horizon
- Instruments can be activated individually; variable stabilisation level
Method of working:
The system contains two independent instrument systems for excellent reliability in conjunction with the sophisticated software. The professional version contains additional instruments which provide autonomous control of all functions.
The position is measured by sensing the ground, using a principle similar to that of the optical computer mouse; the difference is that the positioning system continues to work at altitudes of up to 3 meters or more depending on lighting conditions even at the onset of dusk. A movement sensor senses the ground in flight, i.e. it virtually replaces the eyes of an airborne pilot. Almost every ground surface exhibits contrast, and this allows the system to detect all relative movements in the horizontal direction, just as accurately as a computer mouse on its mat. The supplementary attitude stabilisation features an artificial horizon and three electronic gyros, and works completely independently of the prevailing visual conditions.
As a result, the Helicommand is capable of stabilising the helicopter in the horizontal attitude independent of the visual circumstances (in contrast to previous types of stabilisers). When in Position mode it can also stabilise the machine's position above the ground.
Of course, in exceptional visual conditions, e.g. in the dark, above water, over smooth floor coverings or a featureless snow blanket, the visual sensing systems are unable to supply a signal. If this should occur, the other airborne instruments automatically assume the stabilising role. Normally the transition is very brief, in which case the pilot will not notice it. If it lasts longer, the stabilisation automatically switches from "position mode" to "horizontal mode". In this case the pilot will notice the difference, as he has to compensate for any slow drift by giving straightforward control commands. Even in this situation the level of stabilisation is equivalent to that provided by conventional "inertial control" technology, i.e. it provides tilt stabilisation.