WO1993011407A1

WO1993011407A1 - A device for giving a pilot information about the attitudes of a vehicle

Info

Publication number: WO1993011407A1
Application number: PCT/SE1992/000806
Authority: WO
Inventors: Torbjörn SEGERSTRÖM
Original assignee: Saab Missiles Aktiebolag
Priority date: 1991-11-25
Filing date: 1992-11-24
Publication date: 1993-06-10
Also published as: SE9103475D0

Abstract

A device for direction of the attitudes of especially an air vehicle is described. A navigation equipment, designating the current attitudes of a vehicle in an earth-related coordinate system is understood. The device comprises a source of light such as a laser (6), furthermore a first direction means (7, 14) directing a light beam (4) forward according to a reference direction, and a second direction means (9, 10, 14) which directs a light beam (5) in a direction given by the navigation equipment (11). The device is so arranged that the operator can see in line with the reference direction (4) and the direction given by the navigation equipment (11) and thereby obtain steering information. The first and second direction means can be combined (14).

Description

A DEVICE FOR GIVING A PILOT INFORMATION ABOUT THE ATTITUDES OF A VEHICLE.

The present invention relates to a device for directing the attitude of a vehicle, especially an air vehicle, especially in heading and pitch, the vehicle being provided with navigation equipment, designating the current attitudes of the vehicle in an earthrelated coordinate system.

An operator of an air vehicle, i.e. an aircraft or a helicopter must today fetch steering information from a number of instruments located in the cockpit, such_ s compass and various equipment that works with radiσwaves within the VHF range, such as VOR, Glidbane-Loc.finder, or within the MW/LW range, such as ADF.

It is extremely demanding for the operator to interpret the information from the instruments and to transfer it to steering deflections, at the same time as his vision must be directed out in the direction of the vehicle. In the end phase of an IFR (=Instrument Flying Rule) flight the operator must go from IFR to VFR (Visual Flying Rule) Approach, which is very exacting.

There are other systems for navigation information, e.g. a presentation on the cockpit screen or some sort of sight line indicator, a so-called Head Up display or a presentation built in a helmet to be carried by the operator. Such devices have hitherto been very expensive and thereby available only to military aircraft and helicopters.

There is a need for a simpel, reliable device of the kind mentioned in the introduction. According to the invention such a device is characterized by a combination of:

- at least one source of light, preferably a laser,

- a first direction means, directing a light beam from said source of light forward according to a reference direction,

- a second direction means, arranged to direct a light beam frcm the light source in accordance with at least one attitude direction, in relation to a direction given by said navigation equipment,

SUBSTITUTE SHEET ISA/SE the device being so arranged that the operator can see in line with the reference direction and attitude direction, and thereby receive steering information.

The reference direction can be parallel with the longitudinal axis of the vehicle, but depending on the actual flight case, taking in account the velocity of the vehicle and wind direction, the reference direction can deviate considerably from a direction parallel with the longitudinal direction of the vehicle. The reference direction shall therefore be adjustable.

The source of light is suitably located in front of the operator, outside cockpit, and directs as mentioned a light beam preferably in the reference direction, i.e. in its heading attitude. The operator sees this light beam, if it is dark and especially if it is scmewhat foggy or rainy weather, i.e. particularly when the need for safe navigation information is great.

The operator so acts upon the vehicle attitudes with his steering means that the light beam in the direction of the vehicle coincides with a second light beam, whose direction is decided by the navigation equipment mentioned in the introduction, which gives attitude directions related to an earthrelated coodinate system, through which arrangement the vehicle will travel along the intended flight path, which has been programmed in the navigation equipment.

If the navigation equipment gives information on both heading and pitch attitudes, i.e. is three-dimensionally designed, all the required steering information can be obtained.

In a preferred embodiment of the device according to the invention the light source is followed by a beam expander for expanding the light beam. By this arrangement observation of the two light beams is facili¬ tated. In a preferred embodiment of the device the first direction means consists of a first, semi-opaque mirror and the second direction means of a second mirror, arranged to be adjusted by an adjustment means, acted upon by said navigation equipment.

In another preferred embodiment of the device according to the invention the first and second direction means are combined to one optoacoustical modulator for deflecting the light beam.

The invention is described in the following with reference to three accompanying figures, of which

Figure 1 shows schanatically a plan view of a part of a helicopter provided with a device according to the invention,

Figure 2 shows schematically a plan view of a first embodiment of the device according to the invention, whereas

Figure 3 shows schanatically a plan view of a second embodiment of the device according to the invention.

In Figure 1 a helicopter is designated by 1 with an operator outlined, designated by 2. A source of light is suggested, and is marked by 3. A light beam 4 goes out in the direction of the horizontal direction of the vehicle, showing the heading attitude, while a light beam 5 shows the attitude given and decided by the navigation equipment. In order that the vehicle shall be brought on the correct heading the operator must by acting on the steering means bring the light beams 4 and 5 to coincide.

Figure 2 shows schematically a device to achieve the light beams 4 and 5 in Figure 1. A source of light comprises a laser 6, which can be a 5 mW Argon laser with the wavelength 543 nm. A rigid semi-opaque first mirror 7 reflects some of the incident laser light beam 8 in the form of said light beam 4, whereas the rest of the laser light beam (8) goes on and is reflected by a second mirror 9, arranged movable by means of an adjustment means 10, which is acted upon by the navigation equipment 11 to set the mirror 9 so that the light beam 5 is directed in the direction that the actual attitude, in this case heading, is desired to take. The operator thus controls the steering means, not shown, to steer in the vehicle, so that the light beam 4 coincides with the light beam 5, at which point the vehicle is on the correct heading.

When landing in the dark, the device points out the landing ground on the change over from_IFR-VRF, and designates the glidepath.

In another embodiment of the device according to the invention, which is shown schanatically in Figure 3, there is a laser 6, followed by a radiation expander 12, which expands the light beam ccming from the laser. In this embodiment the aforementioned first and second direction means have been combined and consist in this case of an optoacoustical modulator (14) for deflecting the light. With this construction the advantage is gained, that the deflection of the light beam ccming from the laser can be deflected without any movable parts. The function is that the lasers are rapidly set on and off synchronically with two input signal values to the optoacoustic modulator, i.e. values partly corre¬ sponding to said reference direction, and partly the desired direction value given by the navigation equipment. The quich change between laser on and laser off is not possible for the eye to perceive, and therefore during observation the eye perceives two different beams.

The device according to the invention can also be used to warn other vehicles, especially air vehicles in the vicinity of an airport, and can also serve to identify vehicles.

Claims

A device for directing the attitudes of a vehicle, especially an air vehicle, especially in heading and pitch, the vehicle being provided with navigation equipment, designating the actual attitudes of the vehicle in an earthrelated coordinate system, c h a r a c t e r i z e d by the combination of a) at least one source of light (6), preferably a laser, b) a first direction means (7, 14) directing a light beam (4) from said source of light forward according to a reference direction, c) a second direction means (9, 10, 14) arranged to direct a light beam (5) frcm the source of light in accordance with at least one attitude direction, in relation to a direction given by said navigation equipment (11) , the device being so arranged that the operator can see in line with the reference direction (4) and attitude direction (5) , and thereby obtain steering information.

2. A device according to claim 1, the source of light consisting of a laser, c h a r a c t e r i z e d in that the source of light

(6) is followed by a beam expander (12) for expanding the light beam.

3. A device according to claim 1 or claim 2, c h a r a c t e r i z e d in that the first direction means (7) consists of a first semi-opaque mirror, and the second direction means (9, 10) consists of a second mirror (9) arranged to be adjusted by an adjustment means (10) acted upon by said navigation equipment (11) .

4. A device according to claim 1 or claim 2, c h a r a c t e r i z e d in that the first and the second direction means are combined to an optoacoustic modulator (14) for deflection of the light beam.