Patent GB-1008375-A (GB)
Title: Guidance system test apparatus
Inventor: YAMRON JOSHEPH
IPC: F41G7/00
Filed: 1962-09-27
Abstract: 1,008,375. Testing inertial navigation apparatus. UNITED AIRCRAFT CORPORATION. Sept. 27, 1962, No. 36709/62. Heading G1C. [Also in Division H4] Testing apparatus for an inertial guidance system includes a platform 24 on which the guidance system is mounted, the platform being mounted for rotation with three degrees of freedom and for translation with one degree of freedom. The platform 24 is mounted on an air bearing, 16 Fig. 3, 40 Fig. 2 allowing it to move with the three degrees of rotation freedom and the guidance system labelled 26 in Fig. 3 moves with the platform in simulation of flight conditions. For translation, means are provided to shake the platform with up to 3.5G acceleration in a vertical direction through the air support bearing, the bearing being protected by removing the air pressure, thus allowing the bearing to be clamped on to a "Teflon" (Registered Trade Mark) ring by a clamp. For acceleration forces of up to 0. 5G the bearing need not be clamped. The platform 24 also carries a power supply 28, a flight computer 14 which feeds and is fed with data from the guidance system 26 through digital to analog and analog to digital equipment 30. There are no physical connections to the platform 24 and data is coded and transmitted from and received by the platform by a telemetry link 22 which is connected to a digital equipment 34 (Dig I) mounted on the platform. Off the platform a further digital equipment 44 (Dig II) is provided and this serves a general purpose computer 12 through a digital equipment 46 (Dig m) and a display and control console 54. The platform may be positioned by gas jet reactors controlled by the guidance system and a platform follow-up system comprising three gimbals 38 (Fig. 2) is provided, there being no physical connection between the inner gimbal and the platform under normal conditions. Three antocollimators are provided to ensure that the gimbal system follows the platform so that measurement can be made. For certain conditions it is desirable to drive the platform 14 with the gimbal system and this is effected by clamping the platform to the inner gimbal. The air pressure to the support bearing may be removed and the bearing lowered slightly so that the weight of the platform is taken solely by the gimbal system. If the guiding system is provided with a star sensor, then a star simulator comprising a frame 20 rotatable about a polar axis and carrying optical collimators 18 directing light through the centre of the platform 24 is utilized. The star simulator is driven with an Earth rate motion so that the collimators 18 effectively remain fixed in space so far as the platform 24 is concerned, but the simulator may be driven at higher speed if required. A unit 36 mounted on the platform 24 is used to transmit additional information e.g. pressure or temperature to the console 54 or to the computer 12 via Dig II preferably by use of a telemetry link. The unit 56 may be a tape recorder and may be used to record data from the console control unit 52 or to feed additional data to the system via a direct link to Dig I on the platform. This direct link would preferably be a physical connection which is easily disconnectable.