JP6068129B2 - Antenna pointing system - Google Patents

Description

  The present invention relates to the field of antenna systems. In particular, it relates to a pointing system for a directional antenna.

  The use of a directional (or tracking) antenna to communicate with a relatively moving target at a constant scan angle is well known in the art. Especially in the spacecraft industry, when the antenna is mounted on the aircraft, such a directional RF (radio frequency signal) antenna is preferably used with accurate directivity, high gain, low mass and high Must be reliable.

  Artificial satellites often include a two-degree-of-freedom pointing device to communicate, sense, etc. with other satellites or aircraft. Since the distance between the two is long, pointing accuracy and resolution are very important factors.

  The payloads of these pointing devices are variable, such as the loads of crew members and instruments mounted on rockets and spacecrafts. The payload includes the entire antenna, part of the antenna, sensors, and so on.

A variety of different directional devices have been devised in the past. The simplest structure is two rotary actuators (RA) configured in a connected state, for example, holding a payload such as a reflector as shown in FIGS. 1a and 1b. Especially when relatively small scanning angles are required, for example below ± 30 °, these types of pointing devices have many weaknesses. Alternatively, it has at least a few weaknesses. These weak points are, for example, as follows.
·large;
・ Heavy and structurally inefficient;
・ High cost;
・ Low accuracy;
・ Low resolution;
・ Low reliability;
The need for a retention / release mechanism (HRM);
The need for a fixed predetermined storage position for launch;
The need to move harnesses (RF rotary joints, electrical wiring, etc.); and / or
-In the case of a reflector pointing mechanism, the RF performance is degraded.

  Accordingly, there is a need for an improved antenna pointing system.

Japanese Patent Application Laid-Open No. 2012-044596, Abstract

  Accordingly, it is an object of the present invention to provide an improved antenna pointing system.

The advantages of the antenna pointing system of the present invention are as follows.
・ Small;
・ Light and structurally efficient;
·low cost;
·High precision;
·High resolution;
・ High reliability;
The elimination of the need for a retention / release mechanism (HRM);
・ Selectable immediately before storage position for launch;
Eliminates the need to move harnesses (RF rotary joints, electrical wiring, etc.); and / or
・ In the case of a reflector pointing mechanism, RF performance is improved.

  The first three advantages described above are major advantages when using a rotary actuator.

  According to one aspect of the invention, an antenna pointing system for selectively moving a payload relative to a mounting surface is provided. This antenna pointing system includes the following elements. That is, the antenna directing system of the present invention includes at least one rotary actuator having a crank that moves relative to a fixed portion that is designed to be attached to a mounting surface, and a movable portion that is movable at a first end thereof. And a connecting rod designed to be movably connected to the payload at its second end and a flexible mounting structure for movably mounting the payload to the mounting surface.

  The flexible mounting structure may conveniently employ a universal joint, and the universal joint bearing includes bends, etc., and is preferably located near the geometric center of the payload.

  In one embodiment, there are two rotary actuators, essentially the two second ends of the connecting rod are connected adjacent to the periphery of the payload, and these two rotary actuators are flexible mounting structures. With respect to the center of rotation, and typically the angles are such that the range of payload angular movement around the flexible mounting structure can be fully utilized.

  In one embodiment, with the second end of the connecting rod movably connected to the corresponding first and second mounting points of the payload, the first rotary actuator and the second connecting to each connecting rod There are two rotary actuators.

  Typically, the first attachment point and the second attachment point are angularly separated from each other with respect to the center of rotation of the flexible attachment structure, and the first attachment point and the second attachment point are substantially different. Is adjacent to the periphery of the payload.

  Advantageously, the first attachment point and the second attachment point are 90 ° apart from each other with respect to the center of rotation of the flexible attachment structure.

  Other objects and advantages of the present invention will be understood from the following detailed description, taken in conjunction with the accompanying drawings.

  As described above, the antenna directing system of the present invention has at least one rotary actuator having a crank that moves relative to a fixed portion that is designed to be attached to a mounting surface, and is movable to the moving portion at a first end thereof. A connecting rod designed to be movably connected to the payload at its second end, and a flexible mounting structure that movably mounts the payload to the mounting surface. Thus, an improved antenna pointing system was provided.

The antenna pointing system of the present invention has,
・ Small;
・ Light and structurally efficient;
·low cost;
At least three advantages are major advantages when using a rotary actuator.

In the accompanying drawings, the same reference numerals denote the same elements.
It is a side view of the antenna reflector mounted in the conventional 2-axis gimbal pointing system. It is a rear view of the antenna reflector mounted in the conventional 2-axis gimbal pointing system. It is a perspective view showing one Example of the antenna pointing system of this invention which supported the payload of the antenna reflector movably. It is an expansion upper perspective view of the rotary actuator of the Example of FIG. FIG. 3 is an enlarged top perspective view in which the universal joint of the embodiment of FIG. 2 is partially cut away. FIG. 3 is a partially cutaway top view of the embodiment of FIG. 2.

  The preferred embodiments of the present invention described with reference to the accompanying drawings are only for the purpose of illustrating the present invention and are not intended to limit the present invention in any way.

  2 and 3 are schematic views of an embodiment of a small high resolution / high torque antenna pointing system 10. In the case of the present embodiment, the antenna pointing system 10 is directed to the reflector, but this reflector is attached to the part represented by the mounting surface 14 on another spacecraft existing in the satellite orbit. Part of an RF (Radio Frequency Signal) antenna 12.

  The antenna pointing system 10 includes a rotary actuator 20 together with a crank 22 and a connecting rod 24 to move a payload structure 26 such as an antenna reflector structure, and the payload structure 26 is a flexible mounting structure such as a universal joint structure. The part 28 is held movably on the spot. An example of a completed antenna pointing system 10 is illustrated in FIG.

  In the antenna pointing system 10 of this embodiment, as shown in FIG. 4, the first rotating shaft 30 and the second rotating shaft 31 that are orthogonal to each other in the mounting structure portion 28 that is generally a universal joint are a payload structure portion that is a reflector. The RF performance is improved because it intersects at a point near the 26 geometric centers and defines its center of rotation R. This antenna directing system 10 is driven with two rotational degrees of freedom using two rotary actuators 20. Both of these rotary actuators 20 have their own fixed parts fixed to the base plate (mounting surface 14), and exclude moving harness elements such as RF rotary joints, electrical wiring, and the like. A crank 22 is provided at the output of both rotary actuators 20. A rotary actuator 20 with a crank 22 is shown in FIG.

  As shown in FIG. 3, the long connecting rod 24 includes a first end 32 movably connected to a position near the shaft 23 of the crank 22 and an opposite side movably connected to the payload structure 26 ( The second end 34 is connected to the payload structure 26 at a mounting point 27 around the second end 34 as shown in FIG. The Typically, the first end 32 and the second end 34 are connected via a spherical bearing 35, a flexure, etc. to allow angular movement between the respective connecting elements.

  The payload structure 26 typically includes one or two stationary brackets 36 that can be secured to a surface (mounting surface 14), as shown in FIG. It is movably supported by the cross section 38 around the first rotation shaft 30 via a body, etc. The payload structure 26 is movably supported by the cross 38 around the second rotation shaft 31 via at least one bearing 44, a bent body, etc. extending from or fixed to the payload structure 26. Has been. Further, the payload structure 26 is movably attached to the surface (attachment surface 14) using a universal joint (attachment structure 28) that includes one or two moving brackets 42.

  As clearly shown in FIG. 5, the two attachment points 27 connecting the two second ends 34 of each connecting rod 24 are typically the center of rotation of the flexible attachment structure 28 as indicated by the corner A. They are angularly separated from each other. Typically, the corner A is large enough to utilize the entire angular travel range of the payload structure 26 around the flexible mounting structure 28. For this purpose, the angle A is preferably about 90 °.

  Although this antenna pointing system has been described with a certain range of specificity, the disclosure is merely illustrative of the invention, and the invention is not limited to the features of the embodiments described and illustrated herein. It is to be understood that the invention includes the scope of the claims and their variations and modifications within the spirit of the invention.

DESCRIPTION OF SYMBOLS 10 Antenna pointing system 12 Antenna 14 Mounting surface 20 Rotary actuator 22 Crank 23 Shaft 24 Connecting rod 26 Payload structure 27 Attachment point 28 Mounting structure 30 1st rotating shaft 31 2nd rotating shaft 32 1st end 34 2nd end 35 Spherical Bearing 36 Stationary bracket 38 Cross section 40/44 Bearing 42 Moving bracket A Angle R Center of rotation

Claims (8)

An antenna pointing system that selectively moves the payload relative to the mounting surface,
At least one rotary actuator having a moving part that is rotatable and movable with respect to a fixed part that is attached to the attachment surface, and wherein the moving part supports a crank ;
Is connected to the movable to the crank at a first end, a applied connecting rod to be connected to the movable to the payload at a second end, said first end to said crank A connecting rod that is angularly moved in all directions, and wherein the second end of the connecting rod is angularly moved in all directions with respect to the payload;
A flexible mounting structure for movably mounting the payload on the mounting surface;
An antenna pointing system characterized by comprising:   The antenna pointing system according to claim 1, wherein the number of the rotary actuators is two, and the second end of each connecting rod is movably connected to each corresponding attachment point of the payload.   The antenna pointing system according to claim 2, wherein the attachment points are angularly separated from each other with respect to the rotation center of the attachment structure portion.   The antenna pointing system according to claim 3, wherein each of the attachment points is adjacent to the periphery of the payload.   3. The antenna pointing system according to claim 2, wherein the attachment points are separated from each other by approximately 90 degrees with respect to the rotation center of the attachment structure portion.   The antenna directing system according to claim 1, wherein the mounting structure is disposed adjacent to a geometric center of the payload.   The antenna pointing system according to claim 1, wherein the attachment structure portion is a universal joint. The antenna pointing system according to claim 1, wherein the first end and the second end of the connecting rod are angularly moved with respect to the crank and the payload via respective spherical bearings.