GB2209611A - Remotely controlled optical test equipment - Google Patents

Abstract

Remotely controlled projection apparatus for testing transparencies, particularly aircraft cockpit transparencies, for optical defects comprises a twin beam optical projector 1 of the type described in our UK patent 1,407,812 rotatably mounted on an elevatable stand 2, the stand being provided with remotely operable actuators 5, 6,7 for effecting rotation and elevation movements thereof and individual tilting of the beams of the projector on receipt of signals from a remote controller 8, 9, 10. Video camera 11 may be mounted above the projector 1 on an adjustable boom 12 to enable projected images from the projector 1 to be viewed remotely. <IMAGE>

Description

P7L; COt:TpOrLF flTCT. tTTw\ fltTtf''-' rE T-,LV Ca59Orln n CAl T < .qV FnTaTdT > '- This invention is an improvement to an opi-icai test system which is already the subject of our earlier granted Ut Patent 1,7,12 and it is intended to provide equipment which can be used to test transparencies fron inside an aircraft cockpit whilst it is being operated from a remote location outside of the aircraft cockpit.

The invention disclosed in the granted specification is for an optical unit which projects two images of red and green light. The rid and green images are superimposed on a test screen until they completely overlap to produce yellow spots and lines. The yellow images are next projected onto an aircraft canopy, when the images are projected onto a damaged canopy the separate out to produce red and green component images the degree of separation of the images is an indication of the degree of distortion of the canopy under test. A disadvantage of this system is that the operator has to climb in and out of the aircraft cockpit to make manual adjustments to the apparatus throughout each test.

It is an object of this invention to provide automated optical test equipment which can be fully controlled from a remote position.

According to one aspect of this invention there is provided remotely controlled projection apparatus for testing transparent members said system comprises an optical unit rotatably mounted on a stand said stand is extendable along its axis and has remotely controlled actuators for moving the projection unit on the stand.

A specific embodiment of the invention will now be described with reference to the figures by way of example nnl of +';!iCh:- Figure 1 is a schematic diagram of the present imtent-or!; Figure 2 is a schematic plan view of the projector unit; Figures 3A - 3F are electrical wiring diagram.

Referring to the Figure 1, the system comprises a projector unit supported on a stand 2 which has a flanged portion 3 for co-operating with a base 4. The base 4 is interchangeable which makes it easier to adapt the stand to fit a wide variety of ejector seats. Motors 5, 6 and a differential gear arrangement 7 enable the optical unit 1 to be elevated and panned-b remote control whilst it is inside an aircraft cockpit. An interface housing 8 is provided at the side of the projection unit 1 to allow a control cable 9 and control console 10 to be connected to the side of the unit 1. The housing 8 contains actuator motors M1 to M4 and a series of relays which effect switching of the motors Ml to M4.A video camera 11 is mounted above the optical unit 1 on an adjustable boors 12 to enable the projected images of the unit 1 to be viewed remotely.

In use the stand 2 is placed inside the cockpit of an aircraft and is fitted to a base of appropriate size for the aircraft ejector seat. The projector unit is operated from a remote location using the keypad 10 the keypad is connected to the projector unit by means of cable 9. The projector unit 1 projects a pair of red and green images onto a viewing screen (not shown) and the images on the screen are viewed from the remote location by means of the video camera 11.

Initially the optical unit 1 is elevated on the stand 2 until it projects an image over the top of the aircraft transparency onto a screen (not shomr) to produce a reference image without the transparency interposed between the projector and screen. The video camera 9 i used to record the projected image. When this has been done the optical unit is retracted, by remote control, back down the stand 2 until it projects an image through the transparency and onto the screen to produce a different set of images which are distorted if damage is present in the transparency. Similarly the optical unit 1 can also be rotated, by remote control, into any desired position.

Referring to Figure 2 the projector unit comprises a pair of bulbs 20 a pair of fans 21, a pair of mirrors 22, a red and a green filter 23, 24 respectively with a pair of lenses 25 and a graticule slide 26. A pair of independently controllable lens systems 27 and 28 are positioned in front of the optical unit and are moveable in elevation and azimuth respectively. The lens system 27 is operable by an arrangement of cam 29 and cam follower 30.

The other lens system 28 is pivotally mounted inside the projection unit housing and is rotated in azimuth by means of drive M1. Different azimuthal positions of the system 28 are represented in dotted outline.

Pack and pinion mechanisms 31 and 32 are used to adjust the position of each lens in sliding relationship to the projector housing.

The mechanisms described are similar to those of the manual projection system except the drive shafts are driven by electrical motors. The motors M to M4 are housed inside the detachable housing 8 which is mounted on the side of the projector unit 1. The motors are coupled to the ends of the drive shafts and enable the projection unit to be operated electrically from a remote position via cable 9. Both of the lens systems 27 and 28 are adjustable along axis X1 and X2 so their focus may be independently changed. Lens system 27 can be raised or lowered by remote control to adjust the elevation of its projected image this is achieved by operating motor M4.When the motor rotates it drives the cam 29 around via a drive shaft the rotating cam 29 co-operates with the cam follover 30 to raise or lower the lens system 27 by an amount dependent upon cam angularity. The rotation of the cam can be reversed when required, by reversing the polarity of the voltage applied to the motor this is done by a switching technique disclosed later.

The focus of the lens system 27 is adjusted by operating motor M2, the motor M2 drives a rack and pinion system 31 which moves the lens system on a slideably mounted platform 33. The lens system 28 is pivoted about its centre and the azimuthal position of the lens is adjustable by means motor Ml. The drive shaft of motor M1 operates a worm drive mechanism to convert rotation of the drive shaft into a linear movement to push or pull against one end of the lens system 28, causing the lens system to rotate azimuthally about its pivot. The lens system is mounted on a slideable platform 34 and is adjustable along axis Z2 by operation of motor M3. The motor M3 drives a rack and pinion assembly 32 to move the slideable platform 34 along axis X2. The servo motors described until now can be switched between forward and reverse directions by reversing the polarity of the voltage applied to the motors. Projector bulbs 20 can also be individually controlled so the apparatus can be switched from a binocular test mode to a monocular test r:' & ge. Suitaijle s > itcleJng apparatus is disclosed in Figures 3A to 3F.

Figures 3A to 3F are schematic circuit diagrams and shows how the various servo motors can be switched by remote control. The control console comprises electrical snitches which are connected to relays, the relays are connected to the poles of the different electric motors which are used to drive the projection unit around on the stand and to operate the projection unit controls - such as projector lamps and lenses.

Figure 3A shows how each of the electric motors is connected to a system of relays so it may be switched to run in opposite directions the relays are operated, by remote control, in such a way that the polarity of the voltage across each motor can be reversed thereby causing the motor to turn in the opposite direction. The arrangement of Figure 3A is that required to operate a single motor. The configuration is replicated up to six times, ie, a set of relays is used for each of the six motors in the overall system. Figure 3B shows how the mains electricity supply is stepped down to a 24V DC supply by three transformers before being supplied to the projector lamps and relay control system.

Figure 3C shows the overall control circuit for operating focus, pan and elevation of the optical elements of the projection unit relays are represented in block form with the prefix RL.

Figure 3D is a detailed view of the arrangement of function switches on the control console and the arrangement of their terminals - the terminals are labelled H to S to correspond with the labelling of the terminals shown in Figure 3C.

The Figures of 3E show how the servo motors Ml to M4 are connected to a socket the terminals of the socket are labelled A to M to correspond with the wires and terminals shown in the other Figures.

Figure 3F shows how limit switches are connected to the pan and elevation motors to prevent them from rotating beyond pre-determined limits. The limit switches could be microswitches which are physically switched by the motors or optical elements driven by the motors.

Figure 3G show the switching and fusing of the projector fans and projector lights respectively.

Figure 3E shows the wiring arrangement of a fan step down transformer.

Although only one specific embodiment of the invention has been described so far other embodiments are possible without departing from the scolds of the invention.

Claims (1)

1. CLEW1

   Remotely controlled projection apparatus for testing transparent members said system comprising an optical unit rotatably mounted on a stand said stand is extendable along its axis and has remotely controlled actuators for moving the projection unit on the stand.