Antenna positioning system
An Antenna Positioning System for missile seeker and system development and test comprises an antenna module, and a plurality of tethers, wherein the antenna module is suspended in a position by the tethers and the position is capable of being changed and the antenna module manoeuvred by pulling at least one tether and simultaneously releasing at least one tether. The system is useful for testing and developing Radio Frequency (RF) missile technology in a controlled, simulated environment rather than by live missile firings.
1 . An antenna positioning system which comprises:
an antenna module; and
a plurality of tethers, wherein the antenna module is:
suspended in a position by the plurality of tethers, and wherein:
(a) the antenna module is manoeuvred in response to pulling at least one tether and simultaneously releasing at least one other tether;
(b) the antenna module provides a base for an antenna array assembly, and the antenna module is a rigid structure designed to handle acceleration loads imposed on the antenna module by the plurality of tethers;
(c) the antenna module is constructed from one or more of the materials selected from a group consisting of: plywood, blockboard or particle board, metal fabrication, metal castings, plastic fabrication, plastic moulding, composite fabrication, and composite moulding; and wherein:
i. the antenna array assembly is placed centrally in the antenna module; or
the antenna array assembly is attached to a face of the antenna module which faces a Unit Under Test (UUT).
2 . The antenna positioning system of claim 1 , wherein each tether is attached to the antenna module via an articulated joint; wherein:
the articulated joint has a limited number of degrees of freedom; or
the plurality of tethers are attached around a periphery and a length of the antenna module at positions optimised to provide necessary motion and positional accuracy of the antenna module; or
the antenna module has limited or substantially no roll freedom.
3 . The antenna positioning system of claim 1 , wherein the antenna module has one or more attachment points for attaching to one or more RF cables, wherein the plurality of tethers comprises the one or more RF cables.
4 . The antenna positioning system of claim 1 , wherein the antenna module has frontal dimensions and a shape to suit requirements of the antenna array assembly; wherein:
(i) the antenna module comprises a triangular plate having three corners wherein a tether of the plurality of tethers is attached at each of the three corners.
5 . The antenna positioning system of claim 1 , wherein:
(a) the antenna module has a face which is circular or polygonal; or
(b) the antenna module has three to thirty sides.
6 . The antenna positioning system of claim 1 , wherein:
(a) the antenna module is manufactured of aluminium, synthetic material or composite material; or
(b) the antenna module comprises a transmission device which transmits a signal, wherein the signal is a radio frequency (RF) signal, an infrared signal or a laser signal; or
(c) the antenna module comprises a space frame or is fabricated or moulded.
7 . The antenna positioning system of claim 1 , wherein:
(a) each tether comprises a length of flexible material or components having a first end which is attached to the antenna module and a second end which is attached to a winch or pulley; or
(b) each tether is of suitable materials or components that can be drawn into a winch or through pulleys whilst maintaining the tension as required to manoeuvre the antenna module, the suitable materials or components selected from a group consisting of: (i) single strand metal or polymeric material, (ii) metal, polymeric or composite multistrand cable, (iii) metal, polymeric or composite multistrand flat braid, (iv) single or double sided polymeric toothed belt reinforced with steel or polyparaphenylene terephthalamide fibres, or (v) metal, polymeric or composite chains; or
(c) a tether of the plurality of tethers positioned above the antenna module has a greater cross section than a tether of the plurality of tethers positioned below the antenna module.
8 . The antenna positioning system of claim 1 , wherein the antenna positioning systems comprises:
(a) a minimum of three tethers, each of which are positioned about 120 degrees apart radially; or
(b) a minimum of six tethers; or
(c) each tether is in tension to hold the antenna module in position; or
(d) three to 30 tethers.
9 . The antenna positioning system of claim 1 , wherein;
(a) at least one tether is multistranded; or
(b) at least one tether comprises a flat braid; or
(c) at least one tether comprises a belt, wherein the belt is a toothed belt.
10 . The antenna positioning system of claim 1 , wherein a support structure is provided and winches are arranged around the support structure, wherein:
(a) the support structure comprises a frame having a front side and a rear side, opposite the front side; or
(b) a radial position of the winches on the support structure matches a radial arrangement of tether attachment points on the antenna module; or
(c) a longitudinal spacing of the winches for tethers of the front side and for tethers of the rear side is sufficient to provide 3 degrees of motion, the 3 degrees of motion comprising Surge, Heave and Sway, or 5 degrees of motion, the 5 degrees of motion comprising Surge, Heave, Sway, Pitch and Yaw.
11 . The antenna positioning system of claim 10 , wherein a longitudinal position of the winches is fixed, fixed but adjustable, or dynamically variable.
12 . The antenna positioning system of claim 10 , wherein a longitudinal position of the winches is fixed with a tether passing through an adjustable or dynamically variable position pulley.
13 . The antenna positioning system of claim 12 , wherein a dynamically variable position pulley is positioned longitudinally using a linear servo motor mounted on a linear track with an integrated position feedback device.
14 . The antenna positioning system of claim 1 , further comprising:
a multi axis control system for controlling servo driven winches; and
linear servo motors to adjust a length of each tether between the antenna module and the servo driven winches to position the antenna module in the required position and orientation.
15 . The antenna positioning system of claim 1 , further comprising a control system.
16 . The antenna positioning system of claim 15 , wherein the control system is a multi-axis servo system providing co-ordinated control of a winch and linear motor to wind in, or to let out tethers to position the antenna module at the required azimuth and elevation position and at the required orientation.
17 . The antenna positioning system of claim 15 , wherein the control system receives a series of data from a Hardware in the Loop (HWIL) host computer, including but not limited to position, rate and acceleration, defining a required motion profile of the antenna module.
18 . The antenna positioning system of claim 15 , further comprising a safety system which shuts down the Antenna Positioning System in the event that an error is detected by the control system.
19 . The antenna positioning system of claim 1 , wherein:
the antenna array assembly comprises a plurality of antennae and each antenna of the plurality of antennae is angled to point at the centre of the Unit Under Test (UUT), and the antenna array assembly comprises:
up to 5 antennae representing, in a simulated environment, up to five targets and or jammers, or up to 3 antennae representing, in the simulated environment, up to three targets and or jammers,
the tether is attached to the antenna module via a single axis rotational joint, or
the antenna module comprises a tube closed at an end of the tube to form a face onto which the antenna array assembly is mounted, or
the tube is hexagonal, or
a first set of three tethers of the plurality of tethers are attached to a periphery of the tube near a front of the face and spaced 120 degrees apart, or
a second set of three tethers, that are different than the three tethers in the first set are attached to the periphery of the tube near an end of the tube opposite the front of the face, and spaced 120 degrees apart but offset 60 degrees in relation to the first set of tethers, or
each tether is attached to the module via a dual axis articulated joint.