Antenna positioner with eccentric tilt positioning mechanism

Abstract

To provide methods, systems, and devices for antenna positioning with an eccentric tilt pointing mechanism.SOLUTION: In a radio communication system, an antenna positioner 115-b of an antenna system 105-b includes: a base structure 305-a and an intermediate structure 310-a that is rotatably coupled with the base structure about a tilt axis 306-a being a first axis; an antenna positioner 340-a being a positioning system that is coupled with the intermediate structure and configured to orient an antenna boresight 111-b about at least two angular degrees of freedom with respect to the intermediate structure (e.g., in an elevation angle θE-azimuth angle θA); and an eccentric tilt position mechanism 301-a being an actuator between the base structure and the intermediate structure that is configured to set, change, or maintain an angle θT between the base structure and the intermediate structure. The eccentric tilt position mechanism may include a rotation of an eccentric element 325-a based on a predicted path of a target device.SELECTED DRAWING: Figure 3B

Description

[Background technology]

[0001] cross reference This patent application claims the benefit of U.S. Provisional Patent Application No. 62 / 640,386, filed March 8, 2018, entitled "ANTENNA POSITIONER WITH ECCENTRIC TILT POSITION MECHANISM" by Zimmerman et al., which application is assigned to the assignee hereof and is expressly incorporated herein by reference in its entirety.

[0002] Antenna positioning systems are commonly used in wireless communication systems where an antenna is aligned in a specific orientation to support the establishment and maintenance of a communication link with a target device, such as a satellite, an aircraft, a ground vehicle, a stationary ground target, or the like.

[0003] Positioning systems for aligning antenna boresights with these target devices may require specific performance. For example, to support communication with one or more target devices that may have a wide range of positions relative to the antenna, a positioning system is required to provide a relatively large angular range (e.g., about one or more angular degrees of freedom) for tracking the target devices. In some scenarios, the positioning system must support actuation speeds based on the relationship between the path or position of the target device and the position of the antenna, or the configuration of the positioning axes of the positioning system.

[0004] In one example, when a positioning system is configured to orient the antenna boresight about the azimuth and elevation axes (e.g., in an elevation-azimuth configuration), the overhead passage of a target device can present a problem in tracking the target device. For example, the azimuth velocity associated with tracking the overhead passage of a target device can be infinite (e.g., as the target device passes overhead at an elevation angle of 90 degrees, while the azimuth direction transitions to 180 degrees). If the positioning system cannot support such high azimuth velocities, the associated system may lose communication link with the target device until the positioning system can reposition the antenna boresight along the direction of the target device after the overhead passage. Such communication loss can limit, reduce, or degrade the performance of such antenna systems. Summary of the Invention

[0005] Methods, systems, and apparatuses are described for positioning an antenna using an eccentric tilt pointing mechanism. For example, a system according to the present disclosure can include a base structure and an intermediate structure rotatably coupled to the base structure about a first axis (e.g., a tilt axis). The system can also include a positioning system coupled to the intermediate structure and configured to orient the antenna boresight with respect to the intermediate structure in at least two angular degrees of freedom, which in some examples may generally correspond to an azimuth positioning axis and an elevation positioning axis (e.g., in an elevation-azimuth configuration). The system can also include an actuator (e.g., a tilt actuator) between the base structure and the intermediate structure, which is configured to set, change, or maintain an angle between the base structure and the intermediate structure and, in some examples, can include a control or actuation element based at least in part on a predicted path of a target device.

[0006] The actuator between the base structure and the intermediate structure can include a rotational element configured to rotate about a second axis (e.g., different from the first axis, not coincident with the first axis, not concentric with the first axis), and an eccentric element coupled to the rotational element and the intermediate structure. The eccentric element is attached to or otherwise connected to the rotational element at a location offset from the second axis by an eccentric distance or offset. In some examples, the distance between the base structure and the intermediate structure at the location offset from the first axis can be changed by rotating the rotational element (e.g., by changing the position of the eccentric element relative to the base structure) to change the angle between the base structure and the intermediate structure. In various examples, the eccentric element can include a pin engaged in a slot in the intermediate structure, or the eccentric element is coupled to a first end of a coupler and the intermediate structure is coupled to a second end of the coupler, or the eccentric element takes on other shapes or configurations for adjusting the angle between the intermediate structure and the base structure.

[0007] In some examples, controlling the actuator between the base structure and the intermediate structure includes actuating (e.g., rotating, driving, holding) a rotating element to set, change, or maintain a first angle between the base structure and the intermediate structure about a first axis, where the first angle is determined at least in part based on a predicted path of the target device. The system can then use a positioning system coupled to the intermediate structure to track the target device using antenna boresight while maintaining the first angle (e.g., while maintaining the angular position of the rotating element). The system can select a second angle based at least in part on a second predicted path (e.g., a path of a different target device, a different path of the same target device), and track the target device using antenna boresight while maintaining the second angle.

[0008] Further scope of applicability of the described methods and apparatus will become apparent from the following detailed description, claims, and drawings. The detailed description and specific examples are given for purposes of illustration only, since various changes and modifications within the scope of this description will become apparent to those skilled in the art. [Brief explanation of the drawings]

[0009] A further understanding of the nature and advantages of various aspects of the present disclosure may be realized by reference to the following drawings. In the accompanying drawings, similar components or features have the same reference label. Furthermore, various components of the same type are distinguished by following the reference label with a dash and a second label that distinguishes between the similar components. When only a first reference label is used herein, the description is applicable to any one of the similar components having the same first reference label, regardless of the second reference label.

[0010] [Figure 1] 1 illustrates a simplified diagram of a wireless communication system according to various aspects of the present disclosure.

[0011] [Figure 2] 1 illustrates an example of a target device a passing over an antenna system along a path according to various aspects of the present disclosure.

[0012] [Figure 3A] 1 illustrates an exemplary configuration of an antenna system according to various aspects of the present disclosure. [Figure 3B] 1 illustrates an exemplary configuration of an antenna system according to various aspects of the present disclosure.

[0013] [Figure 4A] 1 illustrates an exemplary configuration of an antenna system according to various aspects of the present disclosure. [Figure 4B] 1 illustrates an exemplary configuration of an antenna system according to various aspects of the present disclosure.

[0014] [Figure 5] 1 illustrates an example of a target device a passing over an antenna system along a path according to various aspects of the present disclosure.

[0015] [Figure 6A] 1 illustrates a diagram of an antenna system using a tilt position mechanism according to various aspects of the present disclosure. [Figure 6B] 1 illustrates a diagram of an antenna system using a tilt position mechanism according to various aspects of the present disclosure.

[0016] [Figure 7] 1 illustrates a diagram of an antenna system using a tilt position mechanism according to various aspects of the present disclosure.

[0017] [Figure 8] FIG. 1 shows a block diagram illustrating a control system for an antenna positioning system according to various aspects of the present disclosure.

[0018] [Figure 9] 1 shows a flowchart illustrating a method for supporting antenna positioning using an off-center tilt pointing mechanism according to an aspect of the present disclosure.

[0019] [Figure 10] 1 shows a flowchart illustrating a method for supporting antenna positioning using a tilt pointing mechanism, according to an aspect of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0020] Aspects of the present disclosure relate generally to antenna positioning devices, and more particularly to antenna positioning devices with an eccentric tilt position mechanism that can set, change, or maintain a relative angle (e.g., tilt angle) between a base structure and an intermediate structure.

[0021] When an antenna positioning system is configured to orient the antenna boresight about one or more positioning axes, a target device moving along a path coincident with one of the positioning axes is difficult for the antenna positioning system to track. For example, when the positioning system is configured to orient the antenna boresight about an azimuth axis and an elevation axis (e.g., in an elevation-azimuth configuration), the azimuth velocity associated with tracking the overhead passage of a target device can be infinite (e.g., during a 180-degree azimuth direction transition as the target device passes overhead at an elevation angle of 90 degrees).

[0022] In accordance with the techniques of the present disclosure, an antenna positioning device with an eccentric tilt positioning mechanism can support reorienting the positioning axis relative to the predicted path of a target device. By providing such control of the relative angle between the base structure and the intermediate structure, systems including the mechanisms of the present disclosure can have superior performance or design characteristics compared to systems lacking such mechanisms or relying on other types of positioners, and can overcome disadvantages associated with positioning systems that orient the antenna boresight with respect to two rotational degrees of freedom.

[0023] Although this disclosure provides examples, they are not intended to limit the scope, applicability, or configuration of embodiments of the principles described herein. On the contrary, the following description will provide those skilled in the art with an enabling description for implementing embodiments of the principles described herein. Various changes may be made in the function and arrangement of elements.

[0024] Accordingly, various embodiments may omit, substitute, or add various operations or components, as appropriate. For example, it should be understood that the methods may be performed in an order different from that described, and that various steps may be added, omitted, or combined. It should also be understood that aspects and elements described with respect to particular embodiments may be combined in various other embodiments. It should also be understood that the following systems, methods, apparatus, and software, individually or collectively, may be components of larger systems, and that other procedures may take precedence or be modified in their application.

[0025] FIG. 1 shows a simplified diagram of a wireless communication system 100 according to various aspects of the present disclosure. The wireless communication system 100 comprises an antenna system 105, which includes an antenna 110 and an antenna positioning device 115. The antenna 110 is associated with an antenna boresight 111, which may point in the direction of the highest signal gain of the antenna 110 or in the nominal pointing direction of the antenna 110. In some examples of the wireless communication system 100, it is desirable to have the antenna boresight 111 pointed in a direction corresponding to the location of a target device 150. The target device 150 may be, for example, a satellite following an orbital path (e.g., geostationary, low Earth, medium Earth, etc.). In other examples, the target device 150 may be a terrestrial target, such as an aircraft in flight, a land or water vehicle, or a moving or stationary terrestrial antenna. The antenna 110 provides communication with the target device 150 via communication link(s) 130, which may be a one-way or two-way communication link.

[0026] In some examples, antenna 110 may be part of a gateway system for a satellite communications system. The gateway system may include a gateway terminal 125 that may be in communication with a network (not shown), such as a local area network (LAN), a metropolitan area network (MAN), a wide area network (WAN), or any other suitable public or private network, and may be connected to other communications networks, such as the Internet, a telephony network (e.g., the public switched telephone network (PSTN), etc.), etc.

[0027] The orientation of the antenna 110 (e.g., of the antenna boresight 111) can be provided by an antenna positioning device 115 (e.g., an antenna positioning system), which can adjust the orientation of the antenna 110 about two or more spatial axes. In some examples, the antenna positioning device 115 can provide azimuth positioning of the antenna 110 (e.g., in a horizontal reference plane, in a tilted reference plane) and elevation positioning of the antenna 110 (e.g., vertically from a horizontal or tilted reference plane). In this manner, the antenna boresight 111 is aimed toward the target device 150 to enhance signal gain along the direction of the antenna 110 and the target device 150.

[0028] In some cases, the antenna positioning device 115 needs to support actuation speeds based on the path of the target device 150 relative to the antenna system 105 (e.g., associated with dynamic movement) or the relationship between the position of the target device 150 relative to the antenna system 105 and the configuration of the positioning axes of the antenna positioning device 115. For example, if the antenna positioning device 115 is configured to orient the antenna boresight 111 about a vertical azimuth axis (e.g., orientation in the horizontal plane) and a horizontal elevation axis (e.g., orientation vertical from the horizontal plane), the azimuth velocity associated with tracking the overhead passage of the target device 150 may be infinite. In other words, when the path of the target device 150 coincides with the azimuth axis of the antenna positioning device 115, the antenna positioning device 115 is required to provide an instantaneous 180-degree shift in azimuth to maintain alignment with the target device 150 as the target device 150 passes the azimuth axis along its path. Such a scenario is particularly true when tracking target devices 150 such as medium Earth orbit (MEO) and low Earth orbit (LEO) satellites in polar orbits, where the lower the Earth orbit of the target satellites and the greater the number of target satellites, the greater the frequency of overhead passes.

[0029] In another example, tracking a geostationary satellite (e.g., another example of target device 150) is associated with similar problems when a terminal (e.g., including antenna system 105) is located directly beneath the satellite. In such an example, wind or base station keeping motion can cause the satellite to drift, thereby necessitating pointing corrections by antenna positioning device 115 (e.g., at a ground station). In various examples at the zenith, the azimuth axis cannot provide the capability to support pointing corrections. Conversely, under such a scenario, corrections are provided only by the elevation axis, and the azimuth angle is used to move the elevation angle between two orthogonal axes for correction.

[0030] If the antenna positioner 115 cannot support such a high azimuth rate or elevation range, the communication link 130 with the target device 150 may be lost (e.g., may cause an outage of communication) until the antenna positioner 115 can reposition the antenna boresight 111 along the direction of the target device 150 (e.g., after reorienting the axis of the antenna positioner 115 after an overhead pass). Such a loss of communication limits, reduces, or degrades the performance of the antenna system 105. While some systems can overcome the limitations of such positioning systems (e.g., X / Y positioners, tilted wedges or train axes under azimuth positioners, or three-axis elevation and cross elevation-azimuth) using various techniques, such techniques are associated with various drawbacks, such as relatively high cost, complexity, or inaccuracy (e.g., due to component backlash).

[0031] According to aspects of the present disclosure, antenna system 105 (e.g., antenna positioning device 115) may include a base structure and an intermediate structure rotatably coupled to the base structure about a first axis (e.g., a tilt axis). Antenna system 105 may also include an actuator between the base structure and the intermediate structure, the actuator configured to set, change, or maintain an angle between the base structure and the intermediate structure. In some examples, the actuator may include control or actuation based at least in part on a predicted path of target device 150. In some examples, the angle between the base structure and the intermediate structure may be selected from a set of angles (a discrete set of tilt angles), such as a discrete number of angular positions between the intermediate structure and the base structure.

[0032] In some examples, controlling the actuators can correspond to a first mode of the antenna system 105 (e.g., tilt mode, train mode, reposition mode, idle mode not supporting communication), and tracking the target device 150 can correspond to a second mode of the antenna system 105 (e.g., tracking mode, active mode supporting communication). In some examples, the antenna system 105 (e.g., antenna positioner 115) can maintain the relative angle between the intermediate structure and the base structure during the second mode or otherwise refrain from rotating the rotational element during the second mode. In some examples, the antenna system 105 can refrain from tracking the target device 150 during the first mode (e.g., when changing to a new tilt angle between a tracking pass associated with the same or a different target device 150). However, the antenna system 105 can actuate other positioning axes (e.g., with respect to the elevation axis, with respect to the azimuth axis) during the first mode. This may be, for example, actuating to a nominal position (e.g., nominal elevation, nominal azimuth), actuating to a predicted position for another pass of the target device 150 (e.g., an elevation or azimuth associated with the target device 150 that returns observation or supports communication along a different next predicted path), or other actuation (e.g., to manage twists or curls in cable bundles associated with the antenna system 105).

[0033] By including actuators of the present disclosure between the base structure and the intermediate structure, the antenna system 105 may provide improved support for maintaining the communication link 130 with the target device compared to other systems. For example, the antenna system 105 may adjust the antenna positioner to accommodate a different predicted path of the target device 150, where such adaptation may reduce motion demands on the antenna positioner 115. In some examples, by setting the angle between the base structure and the intermediate structure, the antenna system 105 may support a reduced elevation angle or a reduced azimuth rate of the antenna positioner 115 while tracking the target device 150 using the antenna boresight 111, thereby improving the ability of the antenna system 105 to maintain the communication link 130 with the target device 150.

[0034] While the disclosed techniques for antenna positioning are described in connection with a terrestrial gateway system, they are also applicable to mobile applications, such as vehicle-mounted antennas or satellite-mounted antennas 110, which may or may not be in communication with a gateway terminal 125. For example, the disclosed mechanisms for selectively tilting an intermediate structure or for selectively tilting an axis of an antenna positioner 115 otherwise associated with a positioning degree of freedom (e.g., in a non-tracking mode) may also be used on an aircraft or satellite passing a stationary or moving target device 150 equipped with an antenna 110. Thus, the disclosed tilt mechanisms may generally be applied in a variety of applications to selectively tilt the positioning axes of an antenna positioner based on the predicted path or position of the target device 150 relative to the antenna system 105, thereby preventing or reducing communication outages associated with target devices 150 that are coincident or aligned with the positioning axes.

[0035] 2 illustrates an example 200 of a target device 150-a passing overhead of an antenna system 105-a along a path 205-a in accordance with various aspects of the present disclosure. In example 200, target device 150-a may be an MEO or LEO satellite, and antenna system 105-a may be a ground facility, such as a component of a gateway system. Path 205-a associated with target device 150-a may follow a generally or primarily north-south orientation, which is an example of a polar orbit.

[0036] To track target device 150-a along path 205-a, antenna positioning device 115 of antenna system 105-a is configured to point antenna boresight 111 (not shown) of antenna system 105-a along different elevation and azimuth angles over time. In example 200, antenna positioning device 115 can be configured with the azimuth axis pointed straight up (e.g., perpendicular to the horizontal plane), so that path 205-a coincides with the azimuth axis. In other words, the position of target device 150-a is determined by the time t for antenna system 105-a configured with its azimuth axis pointed straight up. O This coincides with the azimuthal axis at

[0037] In example 200, the elevation angle of antenna boresight 111 for tracking target device 150-a over time may be shown by elevation angle graph 210, and the azimuth angle of antenna boresight 111 for tracking target device 150-a over time may be shown by azimuth angle graph 220. Elevation angle graph 210 and azimuth angle graph 220 are plotted over time t O The angle is expressed based on the time t O corresponds to the time when the target device 150-a passes directly overhead. The antenna boresight 111 starts in a northerly direction, which has an initial azimuth angle of zero degrees (e.g., θ A,1a ) The azimuth angle can be maintained at the initial azimuth angle until overhead passes at t0. As target device 150-a travels along path 205-a, the elevation angle is increased upfront and then accelerated as target device 150-a approaches the overhead position.

[0038] When target device 150-a reaches an overhead position, it is aligned with the azimuth axis of antenna system 105-a. At this time, in order to track target device 150-a, the elevation angle is increased to a maximum value θ E,max,1 , the maximum of which may be equal to 90 degrees. O , any azimuth angle may support tracking of target device 150-a because antenna borehole 111 aligns with target device 150-a at a 90 degree elevation angle. However, to support tracking along path 205-a, time t O is the time t O The initial azimuth angle θ just before A,1a From time t O The final azimuth angle θ immediately after A,1b , which in the example 200 is 180 degrees. O is also associated with infinite directional acceleration about one or both of the azimuth and elevation axes of the antenna system 105-a (e.g., t O To support the instantaneous transition from positive to negative elevation velocity at t O (to support instantaneous transitions from one azimuth position to another in

[0039] The antenna system 105-a (e.g., the antenna positioning device 115) A,1a From θ A,1b or may not be able to support the azimuth rate required to maintain communication link 130 during the transition to the maximum elevation angle θ E,max,1 (e.g., it may not be possible to support 90 degrees of elevation), or in other cases, t OTherefore, according to examples of the present disclosure, antenna system 105-a (e.g., antenna positioner 115 of antenna system 105-a) may be equipped with an off-center tilt positioning mechanism to selectively or appropriately avoid the conditions illustrated by elevation graph 210 and azimuth graph 220 when target device 150-a follows path 205-a.

[0040] 3A and 3B illustrate example configurations 300-a and 300-b of an antenna system 105-b according to various aspects of the present disclosure. The antenna system 105-b includes an antenna 110-b having an antenna boresight 111-b and an antenna positioning device 115-b configured to orient the antenna boresight 111-b (e.g., toward a target device 150).

[0041] In example antenna system 105-b, antenna positioner 115-b includes antenna positioner 340-a (e.g., a positioning system, a tracking system) configured to orient antenna boresight 111-b with respect to two rotational degrees of freedom (e.g., about first positioning axis 341-a and second positioning axis 342-a relative to intermediate structure 310-a). In some examples, first positioning axis 341-a may be described as an azimuth axis and second positioning axis 342-a may be described as an elevation axis, although other nomenclature and configurations are possible in accordance with the described techniques. In some examples, antenna positioner 340-b may include an elevation positioner and an azimuth positioner between the elevation positioner and the intermediate structure (e.g., in an elevation-azimuth configuration). In some examples, the antenna positioner 340-a may be further configured to rotate elements of the antenna 110-b about an axis (e.g., a third rotational degree of freedom) that is parallel to the antenna borehole 111-b to align the antenna 110-b according to vertical, horizontal, or other signal polarization.

[0042] In an embodiment of antenna system 105-b, antenna positioner 115-b also includes an embodiment of eccentric tilt position mechanism 301-a (e.g., actuator, tilt actuator). For example, antenna system 105-b (e.g., antenna positioner 115-b) comprises base structure 305-a and intermediate structure 310-a, where intermediate structure 310-a is rotatably coupled to base structure 305-a about axis 306-a. The rotatable coupling provides a rotational degree of freedom between base structure 305-a and intermediate structure 310-a and may include any of a ball bearing, roller bearing, journal bearing, bushing, spherical bearing, ball-and-socket joint, etc. Base structure 305-a may be fixedly coupled, for example, to the ground or any other stationary or moving assembly, where the fixed coupling provides a fixed relationship between the structures or objects. In various examples, axis 306-a may or may not be horizontal (eg, when illustrating an embodiment of a fixed terrestrial antenna system 105).

[0043] Eccentric tilt position mechanism 301-a includes a rotational element 320-a rotatably coupled to a base structure about axis 321-a. In various examples, axis 321-a may or may not be horizontal, and axis 321-a may or may not be parallel to axis 306-a. Rotational element 320-a includes an eccentric element 325-a at an offset distance from axis 321-a, which in the example of antenna system 105-b is a coupling attached to a first end of coupler 330. A second end of coupler 330-a is attached to intermediate structure 310-a at coupling location 331-a, which is offset from axis 306-a. In other words, the coupler 330 is shown supporting the eccentric element 325-a, which is coupled to the intermediate structure 310-a (e.g., indirectly via the coupler 330-a) at a location offset from the axis 306-a. While the rotating element 320-a is shown as being rotatably coupled to the base structure 305-a, in other examples, the rotating element 320-a of the eccentric tilt positioning mechanism 301-a may alternatively be rotatably coupled to the intermediate structure 310-a (e.g., by swapping the relative position of the rotating element 320-a and the coupler 330-a between the base structure 305-a and the intermediate structure 310-a). Rotation of the rotating element 320-a may be provided by any suitable mechanism (e.g., a drive element) coupled to the rotating element 320-a, such as an electric motor, a gear motor, a hydraulic motor, and the like.

[0044] Configuration 300-a in FIG. 3A illustrates a neutral or zero tilt position (e.g., of eccentric tilt positioning mechanism 301) of antenna positioner 115-b. In other words, first positioning axis 341-a may be in a vertical position, with antenna positioner 340-a providing control over a rotational degree of freedom measured in illustrated plane 365-a-1 (e.g., a horizontal plane perpendicular to first positioning axis 341-a). Such a configuration is illustrative of a typical or conventional orientation of antenna positioner 340-a to provide azimuth control about first positioning axis 341-a and elevation control about second positioning axis 342-a. For example, azimuth angle θ of antenna positioner 340-a may be adjusted to a value greater than 0.05.A can be measured between the projection of antenna boresight 111-b in plane 365-a-1 and any suitable reference, such as nominal direction 370-a-1 in plane 365-a-1, and the elevation angle θ of antenna positioner 340-a E can be measured as the angle between the antenna boresight 111-b and the plane 365-a-1.

[0045] 3A is an example configuration associated with elevation graph 210 and azimuth graph 220 of example 200 described with reference to FIG. 2 (e.g., when tracking target device 150-a through an overhead pass of path 205-a). For example, during the overhead pass of target device 150-a in example 200, path 205-a may coincide with first positioning axis 341-a. Thus, in configuration 300-a of antenna system 105-b (e.g., of antenna positioning device 115-b), tracking target device 150-a along path 205-a is associated with infinite positioning velocity about first positioning axis 341-a or infinite angular acceleration about one or both of first positioning axis 341-a or second positioning axis 342-a to maintain tracking of target device 150-a in antenna borehole 111-b.

[0046] In some examples, antenna system 105-b (e.g., antenna positioning device 115-b) can be configured to selectively avoid conditions indicated by elevation angle graph 210 and azimuth angle graph 220 by actuating eccentric tilt position mechanism 301 (e.g., rotating rotational element 320-a). For example, to change from configuration 300-a shown in FIG. 3A to configuration 300-b shown in FIG. 3B, antenna system 105-b can include a controller that controls the rotation of rotational element 320-a (e.g., via drive elements, not shown) based at least in part on various conditions related to the predicted path. In various examples, the rotation of rotational element 320-a is adjusted to a maximum elevation angle θ associated with tracking along the predicted path. E , the azimuth angle θ associated with tracking along the predicted path Athe rate of change of (e.g., the maximum rate of change, t O ), angular acceleration (e.g., maximum acceleration, time t O ), the deviation between the first positioning axis 341-a and the direction along the predicted path (e.g., the deviation between the first positioning axis 341-a and the direction along the predicted path at time t O The predicted path 205 direction may be based at least in part on one or more of: the angular deviation between the direction of path 205 at (the ...

[0047] Configuration 300-b in FIG. 3B illustrates a tilted or non-zero tilt position (e.g., of eccentric tilt position mechanism 301-a) of antenna system 105-b. For example, by rotating rotational element 320-a from the position illustrated by configuration 300-a in FIG. 3A to the position illustrated by configuration 300-b in FIG. 3B, eccentric element 325-a, and thus coupler 330-a, can be moved vertically (e.g., upward), correspondingly changing the distance between base structure 305-a and intermediate structure 310-a at coupling location 331-a. In other words, by moving coupling location 331-a upward relative to base structure 305-a, intermediate structure 310-a rotates about axis 306-a, adjusting the tilt of the intermediate structure by tilt angle θ as shown. T can only be generated.

[0048] In the example of antenna system 105-b, the tilt angle θ Tcan be measured between a base structure reference line 307-a associated with (e.g., fixed, aligned) the base structure 305-a and an intermediate structure reference line 311-a associated with (e.g., fixed, aligned) the intermediate structure 310-a. The base structure reference line 307-a is shown as a line passing through the axis 306-a, and the intermediate structure reference line 311-a is shown as a line passing through the axis 306-a and the bonding location 331-a, while the tilt angle θ T can be measured or described with respect to any reference point on the intermediate structure 310-a and the base structure 305-a, or other reference point, line, or plane for conveying rotational or angular change of the intermediate structure 310-a about the axis 306-a (e.g., relative to the base structure 305-a).

[0049] In some examples, one or both of the base structure reference line 307-a or the intermediate structure reference line 311-a may be perpendicular to the axis 306-a. In some examples, the base structure reference line 307-a may be coplanar with the intermediate structure reference line 311-a (e.g., in a plane that is perpendicular to the axis 306-a). In some examples (e.g., when the antenna system 105-b is associated with a terrestrial-based system), the base structure reference line 307-a may be horizontal. In some examples, the intermediate structure reference line 311-a also corresponds to the tilt angle θ when the intermediate structure 310-a is in a particular orientation (e.g., when the positioning axis 341-a is aligned vertically in the neutral tilt position). T = 0), it may be horizontal.

[0050] In another example (not shown), the intermediate structure reference line 311-a may be parallel to or coincident with the positioning axis 341-a, and the base structure reference line 307-a may be parallel to or coincident with the intermediate structure reference line 311-a when the intermediate structure 310-a is at a particular orientation (e.g., a neutral tilt angle or position). For example, if the antenna system 105-b is associated with a terrestrial-based system, the base structure reference line 307-a may be a vertical line, and one or both of the intermediate structure reference line 311-a or the positioning axis 341-a may also be aligned vertically at a neutral or neutral tilt position or angle. However, various other standard conventions can be used to express the rotation or angle between the intermediate structure 310 and the base structure 305. For example, the intermediate structure reference line 311-a is more generally associated with a reference direction, where when the intermediate structure 310-a is in a particular orientation (e.g., an intermediate tilt position or angle, the position or angle associated with the first positioning axis 341-a is in a particular orientation), the intermediate structure reference line 311-a is parallel to or coincident with the base structure reference line 307-a (e.g., corresponding to a zero or neutral tilt angle).

[0051] Rotation of intermediate structure 310-a about axis 306-a causes a corresponding tilt of first positioning axis 341-a, which may be fixed relative to intermediate structure 310-a. Thus, antenna positioner 340-a can provide control with respect to a rotational degree of freedom measured in a non-horizontal plane 365-a-2 (e.g., perpendicular to first positioning axis 341-a). Such a configuration is illustrative of a tilted orientation (e.g., of antenna positioner 340-a) to provide azimuth control about first positioning axis 341-a and elevation control about second positioning axis 342-a. For example, according to configuration 300-b of FIG. 3B , azimuth angle θ of antenna positioner 340-a is Acan be measured between the projection of antenna borehole 111-b on plane 365-a-2 and nominal direction 370-a-2, and the elevation angle of antenna positioner 340-a can be measured between antenna borehole 111-b and plane 365-a-2, where plane 365-a-2 is at an angle θ from the horizontal. T Plane 365-a-2 may be tilted at the same angle as intermediate structure 310-a, but second positioning axis 342-a may or may not be parallel to axis 306-a. For example, when viewed along first positioning axis 341-a, second positioning axis 342-a may be spaced apart from axis 306-a by an angle corresponding to a positioning angle about first positioning axis 341-a (e.g., an azimuthal positioning angle). In other words, positioning about first positioning axis 341-a can change the angular orientation of second positioning axis 342-a relative to axis 306-a.

[0052] 3B is an example of a configuration of antenna positioning device 115-b that can avoid certain characteristics of elevation graph 210 and azimuth graph 220 when tracking target device 150-a through an overhead pass. For example, with configuration 300-b of FIG. 3B, when axis 306-a is aligned along the north-south direction, tilt angle θ T Using the tilted first positioning axis 341-a, the first positioning axis 341-a can be tilted in an east or west direction. Thus, the tilted first positioning axis 341-a may not be aligned with the path 205-a, and the tilt of the antenna positioner 340-a can support gentler operation of the antenna positioner 340-a. For example, with respect to example 200, the tilted orientation of configuration 300-b may result in a reduced elevation angle (e.g., θ ) compared to the neutral orientation of configuration 300-a. T(by an amount equal to θ) and a reduced rate of change of azimuth angle θ. Thus, based on various conditions, antenna system 105-b (e.g., antenna positioner 115-b) can rotate rotational element 320-a based on a prediction or other knowledge of path 205 to provide a tilted orientation of configuration 300-b, thereby avoiding the conditions shown in elevation graph 210 and azimuth graph 220 of configuration 300-a.

[0053] 3A and 3B, can be configured according to various design characteristics that are advantageous for the operation of antenna system 105-b. For example, it can be advantageous to track target device 150 when eccentric element 325-a is held in a vertically upward position (e.g., when eccentric element 325-a is vertically above axis 321-a, as shown in configuration 300-b of FIG. 3B) or a vertically downward position (e.g., when eccentric element 325-a is vertically below axis 321-a, not shown, such as when rotating element 320 is rotated 180 degrees from configuration 300-b of FIG. 3B). In various examples, the rotating element 320-a may be held in an operating position for a specific time interval, such as a duration or mode associated with tracking the target device 150 using the antenna positioner 340-a, where such holding can be supported passively (e.g., by friction) or actively (e.g., by a controllable brake or lock). In some examples, such a configuration of the eccentric element 325-a can reduce the effects of backlash on pointing accuracy. For example, if the eccentric tilt position mechanism 301-a includes a drive element or other mechanism associated with rotational backlash of the rotating element 320-a, the effects of such backlash on pointing accuracy can be minimized when the eccentric element 325-a is aligned perpendicular to the axis 321-a. This is because primarily side-to-side movement of the eccentric element 325-a in such a position (e.g., in response to toggling within the backlash) results in relatively little rotation of the intermediate structure 310-a about the axis 306-a. In contrast, when eccentric element 325-a is aligned horizontally with axis 321-a (e.g., as shown in configuration 300-a in FIG. 3A ), the primarily up-and-down movement of eccentric element 325-a in such a position, corresponding to the backlash of rotating element 320-a, results in a relatively large rotation of intermediate structure 310-a about axis 306-a.

[0054] Furthermore, eccentric geometries, such as the geometry illustrated in antenna system 105-b, are associated with relatively small angular velocities of intermediate structure 310-a at positions where eccentric element 325-a is near perpendicular alignment with axis 321-a. In other words, movement of eccentric element 325-a (e.g., due to the driven rotation of rotating element 320-a) is primarily in the side-to-side direction at such positions, such that rotation (e.g., angular velocity) of rotating element 320-a translates into a relatively slow rotation of intermediate structure 310-a. In contrast, movement of eccentric element 325-a (e.g., due to the driven rotation of rotating element 320-a) is primarily in the up-down direction when eccentric element 325-a is aligned approximately horizontally with axis 321-a, such that rotation of rotating element 320-a translates into a relatively fast rotation of intermediate structure 310-a. Thus, the illustrated geometry can facilitate smoothly guiding intermediate structure 310-a to an operating position (e.g., at or near where eccentric element 325-a is vertically aligned with axis 321-a) with a relatively small angular velocity of intermediate structure 310-a.

[0055] Such a geometry can also provide a favorable mechanical advantage for a drive element configured to drive the rotating element 320-a to move away from, approach, or maintain a particular operating point. In other words, when the eccentric element 325-a is vertically aligned with the axis 321-a, the intermediate structure 310-a and any components attached thereto present a relatively small resistance to the driven rotation of the rotating element 320-a. For example, the drive element can be configured with a relatively small torque to provide an angular acceleration of the intermediate structure 310-a (e.g., about the axis 306-a), an angular deceleration of the intermediate structure 310-a, or to maintain the angular position of the intermediate structure 310-a near an operating point where the eccentric element 325-a is vertically aligned with the axis 321-a compared to a position where the eccentric element 325-a is horizontally aligned with the axis 321-a. That is, the torque is a torque associated with a relatively small angular acceleration of the intermediate structure 310-a (e.g., because the angular velocity of the intermediate structure 310-a may already be developed when the rotating element 320-a passes through such an orientation between one operating position and the other operating position).

[0056] Therefore, for these and other reasons, the antenna positioning device 115-b can be configured (e.g., by a control algorithm) to select to operate the eccentric tilt position mechanism 301-a in one of two positions (e.g., a set of discrete positions) in which the eccentric element 325-a and axis 321-a are vertically aligned or nearly vertically aligned.

[0057] In some examples, backlash of the eccentric tilt positioning mechanism 301-a can be further limited by providing a preload to the eccentric tilt positioning mechanism. In one example of such a preload, the angular movement of the rotating element 320-a can be limited by a physical stop, which can correspond to a position where the eccentric element 325-a is vertically aligned or nearly vertically aligned with the axis 321-a. In various examples, the rotating element 320-a is loaded against such a physical stop either passively (e.g., as driven by gravity acting on various components of the antenna system 105-b), actively (e.g., as driven by a drive element or other power train that imparts torque to the rotating element 320-a), or a combination thereof. For example, a degree of backlash in eccentric tilt positioning mechanism 301-a can be forced by the weight of intermediate structure 310-a and its attached components when axis 306-a is vertically aligned with the center of gravity of such components, and the angular position of rotating element 320-a can be maintained by torque biasing rotating element 320-a against a physical stop. In some examples, such loads can be directed to compliant members that can store potential energy in the form of compressive, tensile, or torsional preloads (e.g., storing preloads), which can mitigate backlash between various components in antenna system 105-b. In some examples, such techniques are associated with improved repeatability or pointing accuracy because the described travel limits (e.g., preloads or travel limits to mechanical stops) are associated with increased mechanical stiffness or reduced backlash. In contrast, antenna systems that include train axes such as rotating wedges do not have a weight bias to eliminate backlash, and wind loading of such antenna systems can cause the backlash of such systems to toggle, resulting in pointing inaccuracies that can be avoided by using the techniques of the present disclosure to tilt the antenna positioner 340-a.

[0058] In some examples, the eccentric tilt position mechanism 301-a may be configured to operate at one of two tilt angles, either holding at one tilt angle or changing to another tilt angle based at least in part on the predicted path of the target device 150. In one embodiment, the eccentric tilt position mechanism 301-a can be configured to operate at a tilt angle θ of either 7.5 degrees or −7.5 degrees. T The tilt angle may be configured to operate at a tilt angle that, in some examples, may correspond to an angular position of the rotating element 320-a where the eccentric element 325-a and axis 321-a are vertically aligned or nearly vertically aligned. In an embodiment in which the eccentric tilt position mechanism 301 supports a tilt rate of 6 degrees per second, the antenna positioner 340-a can be tilted from one tilt position to another in 2.5 seconds (e.g., by rotating the rotating element 320-a by 180 degrees or nearly 180 degrees in 2.5 seconds). In contrast, an antenna system including a rotating wedge may require 30 seconds or more to effect such a change in tilt position (e.g., to rotate the rotating wedge by 180 degrees about a vertical axis).

[0059] In various examples, the disclosed techniques for eccentric tilt positioning include other advantages. For example, providing a small angular range for tilt motion is advantageous for high-reliability cable routing, such as azimuth cable loops, compared to other techniques. Furthermore, the pivoting clevis associated with axis 306-a may be configured to withstand radial thrust moment loads and may utilize low-cost, readily available bearings, such as automotive tapered roller bearings. In contrast, antenna systems involving train axes with rotating wedges may require much larger hollow ring bearings in the drives that rotate the wedges.

[0060] 4A and 4B illustrate example configurations 400-a and 400-b of an antenna system 105-c according to various aspects of the present disclosure. The antenna system 105-c includes an antenna 110-c having an antenna boresight 111-c and an antenna positioning device 115-c configured to orient the antenna boresight 111-c (e.g., toward a target device 150).

[0061] In example antenna system 105-c, antenna positioning device 115-c includes antenna positioner 340-b (e.g., a positioning system, a tracking system) configured to orient antenna boresight 111-c with respect to two rotational degrees of freedom (e.g., about first positioning axis 341-b and second positioning axis 342-b). In some examples, first positioning axis 341-b can be described as an azimuth positioning axis, and second positioning axis 342-b can be described as an elevation positioning axis, although other nomenclature and configurations are possible consistent with the techniques of this disclosure. In some examples, antenna positioner 340-b can include an elevation positioner and an azimuth positioner between the elevation positioner and an intermediate structure (e.g., in an elevation-azimuth configuration). In some examples, the antenna positioner 340-b may be further configured to rotate the antenna 110-c about an axis (e.g., a third rotational degree of freedom) that is parallel to the antenna boresight 111-c to align the antenna according to vertical polarization, horizontal polarization, or other signal polarization.

[0062] Although configurations 400-a and 400-b are illustrated as having antenna boresights 111-c pointed in opposite azimuth directions, in various embodiments, configurations 400-a and 400-b may or may not be associated with a capability or configuration for tracking target device 150 over the full range of azimuth angles. For example, each of configurations 400-a and 400-b can support pointing of antenna boresights 111-c in 360 degrees of azimuth, as long as the elevation angle required to track target device 150 is supported by antenna positioner 340-a and positioning axis 341-a is separated from path 205 of target device 150 by less than a threshold value. If such conditions are not met for one of configurations 400-a or 400-b, the controller of antenna system 105 can selectively transition to the other of configurations 400-a or 400-b.

[0063] In the example antenna system 105-c, the antenna positioner 115-c includes an embodiment of the eccentric tilt position mechanism 301-b (e.g., actuator, tilt actuator). For example, the antenna system 105-c (e.g., the antenna positioner 115-c) includes a base structure 305-b and an intermediate structure 310-b, where the intermediate structure 310-b is rotatably coupled to the base structure 305-b about an axis 306-b. The rotatable coupling provides a rotational degree of freedom between the base structure 305-b and the intermediate structure 310-b. In various examples, the axis 306-b may or may not be horizontal (e.g., when illustrating an embodiment of a fixed terrestrial antenna system 105).

[0064] In the example of antenna system 105-c, the tilt angle θ Tcan be measured between a base structure reference line 307-b associated with (e.g., fixed, aligned) the base structure 305-b and an intermediate structure reference line 311-b associated with (e.g., fixed, aligned) the intermediate structure 310-b. Although shown as being measured between a predetermined positioned base structure reference line 307-b and a predetermined positioned intermediate structure reference line 311-b, the tilt angle θ T can be measured or illustrated with respect to any reference point on the intermediate structure 310-b and the base structure 305-b, or other reference point, line, or plane to convey the rotation or angular change of the intermediate structure 310-b about the axis 306-b (e.g., relative to the base structure 305-b).

[0065] The eccentric tilt position mechanism 301-b also includes a rotation element 320-b that is rotatably coupled to the base structure about an axis 321-b. In various examples, the axis 321-b may or may not be horizontal, and the axis 321-b may or may not be parallel to the axis 306-b. The rotation element 320-b includes an eccentric element 325-b at an offset distance from the axis 321-b, which in the example of the antenna system 105-c is a coupling portion attached to a first end of a coupler 330-b. The second end of the coupler 330-b is attached to the intermediate structure 310-b at a coupling location 331-b that is offset from the axis 306-b. In other words, coupler 330-b is shown supporting eccentric element 325-b (e.g., indirectly via coupler 330-b) coupled to intermediate structure 310-b at a location offset from axis 306-b. Although rotating element 320-b is shown as being rotatably coupled to base structure 305-b, in other examples, rotating element 320 of eccentric tilt position mechanism 301 may be rotatably coupled to intermediate structure 310-b in another manner (e.g., swapping the relative positions of rotating element 320-b and coupler 330-b between base structure 305-b and intermediate structure 310-b).

[0066] In the example of antenna system 105-c, the relative rotation or angle between base structure 305-b and intermediate structure 310-b about axis 306-b is adjusted to a first angle (e.g., a negative tilt angle, −θ 1 , as shown in configuration 400-a of FIG. 4A ) by physical contact between contact point 405-a-1 of base structure 305-b and corresponding contact point 410-a-1 of intermediate structure 310-b. T ) relative rotation or angle between base structure 305-b and intermediate structure 310-b about axis 306-b can be limited at a second angle (e.g., a positive tilt angle, θ , as shown in configuration 400-b in FIG. 4B ) by physical contact between contact point 405-a-2 of base structure 305-b and corresponding contact point 410-a-2 of intermediate structure 310-b. T). In some examples, intermediate structure 310-b can be preloaded at one of contact points 405-a-1 or 405-a-2 by active means, passive means, or a combination thereof, which can reduce or eliminate pointing errors associated with backlash (e.g., of eccentric tilt positioning mechanism 301-b). In some examples, providing contact points 405-a or 410-a can improve the repeatability or precision of tilt positioning, and therefore improve the tracking accuracy of antenna borehole 111-c, by supporting the rotation of intermediate structure 310-b relative to base structure 305-b to a repeatable position. For example, the described extremes of travel (e.g., when preloaded between contact points 405-a and 410-a) are associated with increased mechanical stiffness or reduced backlash. In some examples, antenna system 105-c can be configured to select one of configurations 400-a or 400-b (e.g., based on predicted or otherwise determined path 205) for positioning operations associated with actively tracking target device 150. In some examples, antenna system 105-c can be configured to selectively avoid holding a position between configurations 400-a or 400-b (e.g., selectively avoid a neutral or zero tilt configuration) while tracking target device 150.

[0067] Example antenna system 105-c illustrates an example in which eccentric element 325-b is coupled to intermediate structure 310-b via compliant element 420-a. For example, compliant element 420-a may be a subcomponent of coupler 330-b or a spring integrally molded with the coupler. While compliant element 420 according to the disclosed technology is shown as forming an intermediate portion of coupler 330-b, it may be physically located anywhere between eccentric element 325-b and coupling location 331-b, including a direct physical connection with either or both of eccentric element 325-b and coupling location 331-b. In various examples, the compliant element 420-a includes a coil spring, a beam spring, a leaf spring, a rubber bushing, an air spring, or any other component or combination of components that provides an adjustable force (e.g., based at least in part on the relative displacement between the eccentric element 325-b and the coupling location 331-b or other displacement between the eccentric element 325-b and the intermediate structure 310-b). In various examples, the coupler 330-b is configured to be or otherwise considered to be, in whole or in part, the compliant element 420-a (e.g., the coupler 330-b and the compliant element 420-a may be the same thing). For example, the coupler 330-b may be formed in whole or in part using rubber or another compliant or deformable material or component.

[0068] In various examples, the compliant element 420-a may be configured to accumulate a preload (e.g., a compressive preload, a tensile preload, a bending preload, or a torsional preload) based at least in part on the angular displacement of the rotational element 320-b about the axis 321-b. For example, when the rotational element 320-b is rotated (e.g., by actuating the eccentric tilt position mechanism 301-b) to reach the configuration 400-a shown in FIG. 4A , the coupler 330-b can press the coupling location 331-b upward, causing the intermediate structure 310-b to rotate about the axis 306-b until the intermediate structure 310-b (e.g., contact point 410-a-1) contacts the contact point 405-a-1 of the base structure 305-b. Intermediate structure 310-b may reach contact point 405-a-1 before eccentric element 325-b is aligned perpendicular to axis 321-b (e.g., directly upward), and further rotation of rotating element 320-b toward such alignment compresses compliant element 420-a (e.g., due to a reduced separation between eccentric element 325-b and coupling location 331-b) while maintaining physical contact between contact point 405-a-1 of base structure 305-b and corresponding contact point 410-a-1 of intermediate structure 310-b. Thus, in configuration 400-a shown in FIG. 4A , compliant element 420-a can build up a compressive preload in response to rotating element 320-b driving contact point 410-a-1 toward contact point 405-a-1.

[0069] In another example, when rotating the rotating element 320-b (e.g., by actuating the eccentric tilt position mechanism 301-b) to reach the configuration 400-b shown in FIG. 4B, the coupler 330-b can pull the coupling position 331-b downward (or, if driven by gravity, can resist the downward movement of the intermediate structure 310-b), causing the intermediate structure 310-b to rotate about the axis 306-b until the intermediate structure 310-b (e.g., contact point 410-a-2) contacts the contact point 405-a-2 of the base structure 305-b. Intermediate structure 310-b may reach contact point 405-a-2 before eccentric element 325-b is aligned perpendicular to axis 321-b (e.g., directly downward), and further rotation of rotating element 320-b toward such alignment may stretch or lengthen compliant element 420-a (e.g., due to the increased separation between eccentric element 325-b and coupling location 331-b) while maintaining physical contact between contact point 405-a-2 of base structure 305-b and corresponding contact point 410-a-2 of intermediate structure 310-b. Thus, in configuration 400-b shown in FIG. 4B , compliant element 420-a can build up a tensile preload in response to rotating element 320-b driving contact point 410-a-2 toward contact point 405-a-2.

[0070] In various examples, storing a preload in compliant element 420-a can reduce the effects of backlash in various components of antenna positioning device 115-c. For example, loose physical contact (e.g., “play”) between components may exist at any one or more of axis 306-b (e.g., direct coupling between base structure 305-b and intermediate structure 310-b), axis 321-b (e.g., direct coupling between rotating element 320-b and base structure 305-b), eccentric element 325-b (e.g., direct coupling between eccentric element 325-b and rotating element 320-b, direct coupling between eccentric element 325-b and coupler 330-b), or coupling location 331-b (e.g., direct coupling between coupler 330-b and intermediate structure 310-b). By storing a preload in compliant element 420-a, physical contact between components can bias or load a particular position so that such components cannot move freely or can resist at least some loads, forces, or other toggling motions. For example, such a preload can prevent toggling between components of eccentric tilt position mechanism 301 under operational wind forces likely encountered with antenna system 105-c.

[0071] By storing a preload on the compliant element 420-a, relative motion between the intermediate structure 310-b and the base structure 305-b can be reduced or eliminated (e.g., at operating points where the preload is stored, such as configurations 400-a and 400-b shown in FIGS. 4A and 4B ), thereby improving the pointing accuracy of the antenna boresight 111-c due to the more stable platform (e.g., intermediate structure 310-b) provided for the antenna positioner 340-b. Because such a system is less vulnerable to backlash in the various components, such an arrangement can enable the use of simplified or lower-cost components, such as bearings, couplings, or bushings with tighter tolerances, at the various connection points. Furthermore, by including a soft preload on the contact points 405 or 410, the antenna system 105-c can have an improved safety factor against operational factors, such as extreme wind forces that exceed normal wind loads.

[0072] 4A and 4B are illustrative of two different configurations of antenna positioning device 115-c that can avoid certain characteristics of elevation graph 210 and azimuth graph 220 described with reference to FIG. 2 when tracking target device 150-a through an overhead pass. For example, when axis 306-b is aligned along a north-south direction (e.g., when looking northward into the page of FIG. 4A or 4B), the tilt angle θ of configuration 400-a is T eastward, or tilt angle θ of configuration 400-b. T may be used to tilt first positioning axis 341-b toward the west. Thus, using either configuration in connection with example 200, tilted first positioning axis 341-b may not be aligned with path 205-a, and therefore the tilt of antenna positioner 340-b may support gentler operation of antenna positioner 340-b.

[0073] An eccentric tilt position mechanism, such as eccentric tilt position mechanism 301-b described with reference to Figures 4A and 4B, can be configured according to various design characteristics that are advantageous in the operation of antenna system 105-c. For example, having eccentric element 325-b held in a vertically upper position (e.g., as shown in configuration 400-a of Figure 4A) or a vertically lower position (e.g., as shown in configuration 400-b of Figure 4B) is advantageous in tracking target device 150 for at least the reasons described with reference to antenna system 105-b of Figures 3A and 3B.

[0074] Furthermore, with respect to antenna system 105-c including contact point 405 or 410, an eccentric geometry such as that illustrated for antenna system 105-c is associated with a relatively small angular velocity of intermediate structure 310-a when the physical contact point is reached (e.g., at a position where eccentric element 325-b is approximately perpendicularly aligned with axis 321-b). Thus, the illustrated geometry can facilitate intermediate structure 310-b loosely contacting contact point 405 of base structure 305-b with a relatively small angular velocity of intermediate structure 310-b.

[0075] Furthermore, in the context of antenna system 105-c including eccentric element 325-b, such a geometry can also provide an advantageous mechanical advantage for a drive element configured to drive rotating element 320-b to accumulate a preload on adaptive element 420-a. In other words, when eccentric element 325-b is aligned perpendicular to axis 321-b, compressing or extending adaptive element 420-a can present relatively little resistance to the driven rotation of rotating element 320-a. Therefore, for these and other reasons, antenna positioning device 115-c may be configured (e.g., within a control algorithm) to operate eccentric tilt position mechanism 301-b in either configuration 400-a or configuration 400-b (e.g., a discrete set of tilt angles, a discrete set of angles of rotating element 320-b), where in each configuration eccentric element 325-b and axis 321-b may be aligned perpendicular or near perpendicular.

[0076] 5 illustrates example 500 of target device 150-d passing over antenna system 105-d along path 205-b in accordance with various aspects of the present disclosure. In example 500, target device 150-d may be an MEO or LEO satellite, and antenna system 105-d may be a ground facility such as a component of a gateway system. Path 205-b associated with target device 150-d is an example of a predicted path, which may be predicted or otherwise known by antenna system 105-d before target device 150-d passes antenna system 105-d, before target device 150-d comes into view of antenna system 105-d, or before antenna system 105-d actively tracks target device 150-d. In example 500, path 205-b follows a generally or primarily north-south orientation (e.g., along a polar orbit), and target device 150-a follows a t O 105-d.

[0077] To track target device 150-d along path 205-b, antenna positioning device 115 of antenna system 105-d can be configured to point antenna boresight 111 (not shown) of antenna system 105-d along different elevation and azimuth angles over time. However, unlike example 200 described with reference to FIG. 2 , antenna positioning device 115 of antenna system 105-d in example 500 can be configured to select a tilt angle (e.g., by actuating off-center tilt positioning mechanism 301) so that a positioning axis (e.g., first positioning axis 341, azimuth axis) is not pointed directly upward. In other words, based at least in part on path 205-d, antenna system 105-d can orient a positioning axis (e.g., azimuth axis) such that the positioning axis does not coincide with path 205-d. For example, to support an orbital path 205 of target device 150 primarily along a north-south direction, antenna system 105-d can include axis 306 that is also oriented along a north-south direction. However, in various other examples, the axis 306 of the antenna system 105 may be oriented in other directions, and the direction may be selected to align along the main direction of the path 205.

[0078] If axis 306 of antenna system 105-d is aligned north-south, points 505-a-1 and 505-2 may indicate locations where the positioning axis of a particular tilt configuration may intersect with the elevation angle corresponding to path 205-b. For example, the positioning axis of antenna system 105-d may emanate from the position of antenna system 105-d, and for a given configuration, points 505-a-1 or 505-a-2 may be at time t O , or point 505-a-1 or point 505-a-2 may represent the intersection of the horizontal reference plane coincident with target device 150-d at time t O may represent the intersection of the positioning axis with a spherical reference plane having the same elevation angle as target device 150-d.

[0079] Referring to the example of antenna system 105-c described with reference to FIGS. 4A and 4B, point 505-a-1 is in accordance with configuration 400-a of FIG. 4A (e.g., at a negative tilt angle of −θ T ) corresponds to an intersection of first positioning axis 341-b, where the top of intermediate structure 310-b, and therefore positioning axis 341-b, is tilted toward the east. Further, referring to the example of antenna system 105-c described with reference to FIGS. 4A and 4B, point 505-a-2 ... T ) corresponds to an intersection of first positioning axis 341-b, where the top of intermediate structure 310-b, and therefore positioning axis 341-b, is tilted toward a westward direction. Thus, referring to the example of antenna system 105-c, configuration 400-a or configuration 400-b can be selected by antenna system 105-c based at least in part on path 205-b, which can help avoid adverse performance characteristics associated with first positioning axis 341-b being aligned with path 205-b.

[0080] In example 500, the elevation angle of antenna boresight 111 for tracking target device 150-d over time is shown by elevation angle graph 510, and the azimuth angle of antenna boresight 111 for tracking target device 150-d over time is shown by azimuth angle graph 520. Elevation angle graph 510 and azimuth angle graph 520 are plotted against time t, which corresponds to the time when target device 150-d passes directly overhead. O The angle is indicated based on the angle.

[0081] In comparison to the elevation angle graph 210 and azimuth angle graph 220 described with reference to example 200, the selection of a tilted positioning configuration (e.g., configuration 400-a or configuration 400-b) illustrated by example 500 is associated with looser performance requirements for the associated antenna positioner 340. For example, the maximum elevation angle θ of example 500 E,max,2 is the maximum elevation angle θ of Example 200 E,max,1 may be smaller than (e.g., θ E,max,2 may be less than 90 degrees and may be between 90 degrees and θT For azimuth positioning of example 500, to support tracking along path 205-d, time t O The initial azimuth angle θ A,2a to the final azimuth angle θ A,1b t O azimuth angle θ (with a finite peak azimuth velocity at θ ) A,2a ~θ A,2b The range of the azimuth angle θ of example 200 A,1a (for example, the azimuth angle θ A,2a ~θ A,2b (The range of t may be less than 180 degrees.) Furthermore, in contrast to example 200, time t O may not be associated with infinite directional acceleration about either the azimuth or elevation axis of the antenna system 105-d (e.g., t O does not require an instantaneous transition from a positive to a negative elevation velocity at t O (These do not require an instantaneous transition from one azimuth position to another in the

[0082] Therefore, according to various examples of the present disclosure, the antenna system 105-d (e.g., antenna positioning device 115) of example 500 including the eccentric tilt position mechanism 301 can avoid the adverse conditions indicated by the elevation graph 210 and the azimuth graph 220 when the target device 150-d follows the path 205-d, thereby improving the ability of the antenna system 105-d to maintain the communication link 130 with the target device 150-d.

[0083] Antenna system 105 (e.g., a controller associated with antenna system 105, a controller of a gateway system in communication with antenna system 105) can perform various operations, calculations, or decisions to support selecting a particular tilt configuration for antenna system 105 (e.g., configuration 400-a or configuration 400-b in the context of antenna system 105-c) based on conditions associated with the predicted path. In some examples, such selection may be based at least in part on which side of axis 306a the predicted path 205 passes. The configuration associated with point 505-a-1, for example, may be selected whenever path 205 is west of antenna system 105-d, and in some examples, the configuration associated with point 505-a-1 is associated with an azimuth angle that tracks within an angular range of 180 degrees to 360 degrees. The configuration associated with point 505-a-2 may be selected, for example, whenever path 205 is east of antenna system 105-d, and in some examples, the configuration associated with point 505-a-1 is associated with an azimuth angle that tracks within an angular range of 0 to 180 degrees. The configuration associated with either point 505-a-1 or 505-a-2 may be used for directly overhead path 205, although in various examples, one configuration or another may be assigned to the directly overhead pass, or the controller may decide to maintain a particular configuration (e.g., refrain from changing the configuration and maintain the angular rotation of intermediate structure 310 relative to base structure 305) based on detecting the directly overhead pass.

[0084] Additionally or alternatively, the selection between each tilt configuration may be determined by the maximum elevation angle θ E , azimuth θ AThe calculation may be based at least in part on one or more of the rate of change of the tilt angle, the angular acceleration about one or both of the first positioning axis 341 or the second positioning axis 342, the separation between the first positioning axis 341 and the direction along the predicted path, or some other characteristic associated with tracking along the path 205 in one or more tilt configurations, including a comparison between the current tilt configuration and the new tilt configuration. For example, a controller associated with the antenna system 105 may perform such calculations at each of a set of tilt configurations of the antenna system 105 and may command the antenna system 105 to maintain the tilt angle unless a particular calculation at the current tilt configuration exceeds a threshold (e.g., within a threshold deviation between the first positioning axis 341 and the path 205 and outside a threshold elevation angle or operating range of the elevation positioner).

[0085] In an example of selection based on the capabilities of antenna positioner 340, the selection between each tilt configuration is based at least in part on the elevation capabilities of antenna positioner 340 (e.g., the angular range about positioning axis 342). For example, if antenna positioner 340 is associated with elevation control relative to intermediate structure 310 in the range of 0 to 90 degrees, terrestrial antenna system 105 may be unable to track target device 150 near the western horizon when operating in the tilt configuration associated with point 505-a-1 (e.g., because target device 150 is below the minimum elevation angle supported by the associated antenna positioner 340). Thus, under some circumstances, if path 205 is particularly far from the west of antenna system 105-d, the tilt configuration associated with point 505-a-2 may be selected even though path 205 is west of antenna system 105-d. In other words, in some examples, one tilt configuration or another may be selected based at least in part on where the path 205 is located within one or more angular ranges about the axis 306, which may take into account or compensate for the angular range about the positioning axis 342 (e.g., positioner capability).

[0086] Additionally or alternatively, antenna positioner 340 may be designed or configured to compensate for aspects of off-center tilt positioning mechanism 301. For example, a ground antenna system 105 associated with a tilt configuration (e.g., about axis 306) with a tilt of ±7 degrees can be configured with an elevation positioner (e.g., of antenna positioner 340) having a range for intermediate structure 310-a (e.g., about positioning axis 342) between −7 degrees or less and 83 degrees or more, which elevation positioner can support an extended tracking range of antenna positioner 340 in each of a set of tilt configurations.

[0087] 6A and 6B illustrate an example of an antenna system 105-e according to various aspects of the present disclosure. The antenna system 105-e includes an antenna 110-e having an antenna boresight 111-e and an antenna positioning device 115-e configured to orient the antenna boresight 111-e (e.g., toward a target device 150).

[0088] In example antenna system 105-e, antenna positioning device 115-e includes antenna positioner 340-c (e.g., a positioning system, a tracking system) configured to orient antenna boresight 111-e with respect to two rotational degrees of freedom (e.g., about first positioning axis 341-c and second positioning axis 342-c). In some examples, first positioning axis 341-c may be described as an azimuth positioning axis, and second positioning axis 342-c may be described as an elevation positioning axis, although other nomenclature and configurations are possible depending on the technology being described. In some examples, antenna positioner 340-c includes elevation positioner 640 and azimuth positioner 630 between elevation positioner 640 and intermediate structure 310-c (e.g., in an elevation-azimuth configuration). In some examples, the antenna positioner 340-c may be configured to rotate the antenna 110-e (e.g., a radiating element or a receiving element of the antenna 110-e) about an axis (e.g., a third rotational degree of freedom) that is parallel to the antenna boresight 111-e to align the antenna according to vertical polarization, horizontal polarization, or other signal polarization.

[0089] In the example antenna system 105-e, the antenna positioning device 115-e also includes an embodiment of an eccentric tilt position mechanism 301-c (e.g., an actuator, a tilt actuator). For example, the antenna system 105-e (e.g., the antenna positioning device 115-e) includes a base structure 305-c and an intermediate structure 310-c, where the intermediate structure 310-c is rotatably coupled to the base structure 305-c about an axis 306-c. The rotatable coupling provides a rotational degree of freedom between the base structure 305-c and the intermediate structure 310-c. In various examples, the axis 306-c may or may not be horizontal.

[0090] The eccentric tilt positioning mechanism 301-c also includes a rotational element 320-c that is rotatably coupled to the base structure about an axis 321-c. In various examples, the axis 321-c may or may not be horizontal, and the axis 321-c may or may not be parallel to the axis 306-c. The rotational element 320-c includes an eccentric element 325-c at an offset distance from the axis 321-c, which in the antenna system 105-e is a coupling attached to a first end of a coupler 330-c. A second end of the coupler 330-c is attached to a compliant element 420-b, which in the example of the eccentric tilt positioning mechanism 301-c may be a beam spring fixedly coupled to the intermediate structure 310-c at a coupling location 331-c that is offset from the axis 306-c. In other words, coupler 330-c illustrates an embodiment that supports eccentric element 325-c (e.g., indirectly via coupler 330-b and adaptive element 420-b) that is coupled to intermediate structure 310-c at a position offset from axis 306-c.

[0091] In the example antenna system 105-e, the drive element 610 is shown as a slewing drive, which includes a worm gear driven by a motor that rotates a gear perpendicular to the worm gear's axis (e.g., the axis is coupled to the rotating element 320-c). The slewing drive is an example of a gearbox or gear motor used to support the controlled rotation of the rotating element 320-c. Slewing drives have particular advantages in the eccentric tilt position mechanism 301 of the present disclosure. For example, the slewing drives in the disclosed system can support gear ratios of 60:1 to 80:1, which can adequately resist reverse drive. Therefore, the slewing drive can support lower-cost gear motors and drive weight. Furthermore, with a relatively small travel range and near-zero backlash, the resulting higher ratios can support a single drive operation for lower cost (e.g., compared to other technologies that may require multiple motors to compensate for backlash). Furthermore, the slew drive and gear motor are relatively compact and do not impede full azimuth motion (e.g., 360 degrees in azimuth) and full elevation motion (e.g., 90 degrees in elevation). While other actuators can be used to provide tilt drive, such other actuators cannot be miniaturized to generate the same amount of drive force.

[0092] In the example of antenna system 105-e, eccentric tilt position mechanism 301-c includes encoder 620, which can provide a signal indicative of the current tilt position (e.g., about axis 306-c), which is provided to a controller for various tilt positioning or borehole tracking operations described herein. Encoder 620 can be any suitable encoder for determining the relative angular orientation between intermediate structure 310-c and base structure 305-c, which can measure the angular orientation directly or take another suitable measurement from which the angular orientation can be determined. In various examples, encoder 620 can be any of a magnetic encoder, an optical encoder, a conductive encoder, a resolver, a synchro, etc. The eccentric tilt position mechanism 301 may include an encoder 620 to indicate the tilt position (e.g., about axis 306-c), but the eccentric tilt position mechanism 301 may additionally or alternatively include an encoder that provides an indication of the angular position of the rotating element 320 (e.g., about axis 321), which indication is provided to a controller for various tilt positioning or aim tracking operations described herein.

[0093] In the example of antenna system 105-e, the relative rotation or angle between base structure 305-c and intermediate structure 310-c about axis 306-c is limited at a first angle or position by physical contact between contact point 405-b-1 on base structure 305-c and corresponding contact point 410-b-1 on intermediate structure 310-c. Further, the relative rotation or angle between base structure 305-c and intermediate structure 310-c about axis 306-b is limited at a second angle or position by physical contact between contact point 405-b-2 on base structure 305-c and corresponding contact point 410-b-2 on intermediate structure 310-c. In some examples, intermediate structure 310-c can be preloaded at one of contact points 405-b-1 or 405-b-2 by active means (e.g., using drive element 610), passive means, or a combination thereof, which can reduce or eliminate pointing errors associated with backlash (e.g., of eccentric tilt positioning mechanism 301-c). In some examples, providing contact points 405-b or 410-b can improve the repeatability of tilt positioning and therefore improve tracking accuracy of antenna boresight 111-e by supporting the rotation of intermediate structure 310-c relative to base structure 305-c in a repeatable position.

[0094] In the example of eccentric tilt position mechanism 301-c, adaptive element 420-b can be configured to accumulate a bending preload based at least in part on the angular displacement of rotational element 320-c about axis 321-c. For example, rotating rotational element 320-c in a clockwise direction in the illustration of FIG. 6B (e.g., by driving drive element 610) can cause coupler 330-c to press upward against coupling location 605, which can correspondingly press upward against coupling location 331-b, thereby rotating intermediate structure 310-c about axis 306-c until intermediate structure 310-c (e.g., contact point 410-b-1) contacts contact point 405-b-1 of base structure 305-c. Intermediate structure 310-c can reach contact point 405-b-1 before eccentric element 325-b is aligned perpendicularly (e.g., directly upward) to axis 321-c, and further rotation of rotating element 320-c into such alignment can cause compliant element 420-b to bend (e.g., due to upward movement of coupling location 605 while coupling location 331-c maintains a position corresponding to contact between contact point 410-b-1 and contact point 405-b-1). Thus, in a configuration in which contact point 405-b-1 and contact point 410-a-1 are driven into physical contact, compliant element 420-b can accumulate a first bending preload in response to the driven contact (e.g., corresponding to a configuration in which eccentric element 325-c is vertically aligned about axis 321-c).

[0095] In another example, rotating the rotation element 320-c in a counterclockwise direction in the view of FIG. 6B (e.g., by driving the drive element 610) can cause the coupler 330-c to pull the coupling location 605 downward, which can correspondingly pull the coupling location 331-b downward, thereby rotating the intermediate structure 310-c about the axis 306-c until the intermediate structure 310-c (e.g., the contact point 410-b-2) contacts the contact point 405-b-2 of the base structure 305-c. Intermediate structure 310-c can reach contact point 405-b-2 before eccentric element 325-c is aligned perpendicularly (e.g., directly downwardly) to axis 321-c, and further rotation of rotating element 320-c into such alignment can cause compliant element 420-b to bend (e.g., due to downward movement of coupling location 605 while coupling location 331-c maintains a position corresponding to contact between contact point 410-b-2 and contact point 405-b-2). Thus, in a configuration in which contact point 405-b-2 and contact point 410-a-2 are driven into physical contact, compliant element 420-b can accumulate a second bending preload in response to the driven contact (e.g., corresponding to a configuration in which eccentric element 325-c is vertically aligned about axis 321-c). The second bending preload can be considered a negative or opposite bending compared to the first bending preload.

[0096] In various examples, storing a preload on compliant element 420-b can reduce the effects of backlash in various components of antenna positioning device 115-e. For example, loose physical contact (e.g., “play”) between components may exist at any one or more of axis 306-c (e.g., a direct connection between base structure 305-c and intermediate structure 310-c), axis 321-c (e.g., a direct connection between rotation element 320-c and base structure 305-c), eccentric element 325-c (e.g., a direct connection between eccentric element 325-c and rotation element 320-c, a direct connection between eccentric element 325-c and coupler 330-c), coupling location 605 (e.g., a direct connection between coupler 330-c and compliant element 420-b), or coupling location 331-c (e.g., a direct connection between compliant element 420-b and intermediate structure 310-c).

[0097] By storing a preload on the compliant element 420-b, physical contact between components can bias or load a specific position so that such components cannot move freely or can at least resist some load, force, or other toggling motion. For example, such a preload can prevent toggling between components of the eccentric tilt positioning mechanism 301-c due to operational wind forces likely to occur with the antenna system 105-e. Thus, by storing a preload on the compliant element 420-b, relative movement between the intermediate structure 310-c and the base structure 305-c can be reduced or eliminated (e.g., at the operating point where such a preload is stored), which can improve the pointing accuracy of the antenna boresight 111-e due to a more stable platform (e.g., a more stable position of the intermediate structure 310-c) provided for the positioning system 340-c. Such an arrangement allows for the use of simplified or lower cost components, such as tight tolerance bearings, couplings, or bushings, at the various connection points, because such a system is less vulnerable to backlash in the various components.

[0098] Although the drive element 610 of antenna system 105-e is shown as a pivot drive, various other types of drive elements 610 can be used to support the disclosed techniques for tilt positioning, which may be used in combination with physical stops (e.g., contact points 405, 410). Additionally, such other types of drive elements 610 can be used in combination with various types of compliant elements 420 to build up preload, which can reduce the effects of backlash and improve accuracy for pointing or positioning the antenna borehole 111.

[0099] 7 shows a diagram of an antenna system 105-f employing an antenna positioner 340-d and an eccentric tilt positioning mechanism 301-d according to various aspects of the present disclosure. The antenna positioner 340-d can provide positioning of the antenna boresight 111 (not shown) about first and second positioning axes 341-d, 342-d (e.g., relative to the intermediate structure 310-d). The eccentric tilt positioning mechanism 301-d can be configured to rotate the intermediate structure 310-d, and thus the antenna positioner 340-d, relative to the base structure 305-d about axis 306-d.

[0100] The eccentric tilt position mechanism 301-d illustrates an example in which the relative rotation or angle between the base structure 305-d and the intermediate structure 310-d is controlled, set, or maintained by actuating the rotation element 320-c (e.g., rotating the rotation element 320-c about the axis 321-d) using an eccentric element 325-d (e.g., a pin) engaged in a slot 710 of the intermediate structure 310-d. In other words, the eccentric tilt position mechanism 301-d illustrates an example in which the eccentric element 325-d is supported on the intermediate structure 310-d at a position offset from the axis 306-d (e.g., directly via the slot 710). In some examples, such actuation may include using drive element 610-b (e.g., a pivoting drive) to rotate rotational element 320-c such that eccentric element 325-d is in a particular position (e.g., such that eccentric element 325-d is vertically aligned or nearly vertically aligned with axis 321-d). In some examples, such an embodiment may be used to omit coupler 330 from the tilt positioner.

[0101] Although contact point 405, contact point 410, or compliance element 420 are not shown in antenna system 105-f, an eccentric tilt position mechanism 301 including an eccentric element 325-d (e.g., a pin) engaged in slot 710 may include one or more of contact point 405, contact point 410, or compliance element 420 in accordance with the techniques described herein (e.g., as described with reference to antenna system 105-c in the diagrams of Figures 4A and 4B).

[0102] 8 shows a block diagram 800 illustrating a control system 810 for the antenna positioning device 115 according to various aspects of the present disclosure. The control system 810 can be configured to control one or both of the tilt positioner (e.g., eccentric tilt position mechanism 301) or antenna borehole positioner (e.g., antenna positioner 340) described with reference to FIGS. 1-6. For example, the control system 810 can include a tilt position controller 830 for controlling the alignment of the intermediate structure 310 or the antenna positioner 340 about a tilt axis (e.g., about axis 306 based on a predicted or future path or position of the target device 150), and a target device tracking controller 840 for actively tracking the target device 150 by positioning the antenna borehole 111 with respect to two or more rotational degrees of freedom (e.g., about the first positioning axis 341 or the second positioning axis 342 based on the current position of the target device 150). The control system 810 can be configured to set an initial position (e.g., initial tilt position, initial aim alignment) after installation or start-up, correct various predicted or current target paths (e.g., path 250) or positions of the target device 150, position the antenna aim 111 toward a new target device 150 or target path 205, or respond to any other control commands.

[0103] The control system 810 may include a positioning axis controller 820 for defining or monitoring various states of the antenna positioner 115 or for providing other high-level functions of the antenna positioner 115. The states of the antenna positioner 115 may include an initialization state, an operating state, or a fault state, and the positioning axis controller 820 may change between states or maintain a particular state in response to signals from outside the control system 810, such as pre-programmed commands or signals received from a path finding component 850, a tilt position controller 830, a target device tracking controller 840, or a position detector, encoder, sensor, relay, user command, or any other control signal. In some examples, the positioning axis controller 820 can manage operation according to different modes, such as a first mode corresponding to a repositioning mode, a tilt mode, or a retraining mode (e.g., when tilting the intermediate structure 310 or the antenna positioner 340 from one angular position to another relative to the base structure 305, when not actively tracking the target device 150, and when a communication link 130 has not been established with the target device 150), or a second mode corresponding to a tracking mode or a tracking pass (e.g., when tracking the position of the target device 150 to support active communication via the communication link 130). The positioning axis controller 820 can also generate various control signals that are delivered to the tilt position controller 830 or the target device tracking controller 840 in response to pre-programmed commands or signals received from the path detection component 850, the tilt position controller 830, the target device tracking controller 840, or signals from components external to the control system 810, such as position detectors or encoders, resolvers, synchros, sensors, relays, input devices (e.g., user commands or automated control commands), or other control systems.

[0104] The positioning axis controller 820 can receive signals or commands related to the predicted path 205 of the target device 150, the current position of the target device 150, the current tilt position, the current alignment of the antenna boresight, and others for providing commands or signals to the tilt position controller 830 or the target device tracking controller 840. For example, the positioning axis controller 820 can provide commands to the tilt position controller 830 to rotate the intermediate structure 310 or the antenna positioner 340 to a particular angular orientation (e.g., a tilt angle) and then maintain the angular orientation (e.g., a first mode of operation of the positioning axis controller 820, the control system 810, or the associated antenna system 105). While the intermediate structure 310 or the antenna positioner 340 is maintained at a constant angular orientation (e.g., by the tilt position controller 830), the positioning axis controller 820 can provide commands to the target device tracking controller 840 to operate the antenna positioner 340 to provide a selected antenna positioning (e.g., to actively track the target device 150).

[0105] In various examples, the control provided by the positioning axis controller 820 (e.g., selection of operating modes, commands, or parameters provided to the tilt position controller 830 or the target device tracking controller 840) may be based on various conditions, characteristics, or capabilities of the associated antenna system 105. For example, various aspects of the control may be based on or otherwise responsive to the azimuth capabilities of the antenna positioner 340, the elevation capabilities of the antenna positioner 340, or a combination thereof. In some examples, various aspects of the control may be based on or otherwise responsive to the angular deviation between the positioning axes of the angular degrees of freedom of the positioning system (e.g., first positioning axis 341, second positioning axis 342) and the predicted path 205 of the target device 150 (e.g., the angle about axis 306 or second positioning axis 342 between the orientation of the first positioning axis 341 and the predicted path 205 meeting or below a threshold). In some examples, various aspects of the control may be based on, or may otherwise respond to, a predicted angular rate (e.g., azimuth or elevation velocity or acceleration meeting or exceeding a threshold) of the positioning system 340 associated with (e.g., required for) tracking the target device 150 along the predicted path 205 of the target device 150. In some examples, various aspects of the control may be based on, or may otherwise respond to, a predicted angle (e.g., elevation angle meeting or exceeding a threshold) of the antenna positioner 340 associated with (e.g., required for) tracking the target device 150 along the predicted path 205 of the target device 150.

[0106] The path detection component 850 can be configured to identify or determine a predicted path of the target device. In some examples, the path detection component 850 can receive information corresponding to an orbital path or information associated with a satellite, such as the longitude or other orientation or position of the satellite's path relative to the antenna system 105, the tilt axis (e.g., axis 306), or the positioning axis (e.g., first positioning axis 341). In some examples, the path detection component 850 can receive or determine position information about the target device 150 over time and can calculate (e.g., by estimation) a predicted path of the target device 150 from such information. Such calculations can be useful in scenarios where the described tilt positioner is used to reorient one or more axes of the antenna positioner 340 in response to a moving target device 150 or mobile antenna system 105 that does not have a predetermined path, such as an airplane, ground vehicle, or other such target device 150 or antenna system 105. The path detection component 850 can pass various information to the positioning axis controller 820, which can make various calculations or decisions based on such information (e.g., whether to hold or activate a tilt positioner).

[0107] The tilt position controller 830 can be configured to control a tilt actuator (e.g., the eccentric tilt position mechanism 301) based at least in part on the predicted path 205 of the target device 150. In some examples, such an actuator can be coupled between the base structure 305 and an intermediate structure 310 that is rotatably coupled to the base structure 305 about an axis 306. In some examples, this control includes powering or otherwise actuating a drive element 610 (e.g., a swivel drive, a motor, a drive train) that can rotate a rotation element 320 to set, change, or maintain the angle between the base structure 305 and the intermediate structure 310. In some examples, such actuation can include or otherwise cause rotation of the intermediate structure 310 until physical contact is achieved between the intermediate structure 310 and the base structure 305. In some examples, such actuation may include or otherwise cause a preload of the compliant element 420 between the actuator (e.g., between the drive element) and one of the base structure 305 or intermediate structure 310. In some examples, such actuation may include changing to or maintaining a particular angular position selected from a set of discrete angular positions (e.g., one of two angular positions, such as the tilt angle corresponding to one of configurations 400-a or 400-b described with reference to FIGS. 4A and 4B ).

[0108] In some examples, the tilt position controller 830 can generate control signals for the tilt position drive elements based on pre-programmed instructions or other instructions or signals received from outside the control system 810, such as other signals from the positioning axis controller 820 or the target device tracking controller 840, feedback signals from the tilt position drive elements, or encoder signals or any other signals. The tilt position controller 830 can deliver commands or signals to the tilt position drive elements regarding the magnitude and direction of movement for the tilt positioner (e.g., the eccentric tilt position mechanism 301). The tilt position drive elements can include power transistors for generating drive currents for motors or other actuators from a power source according to the commands or signals to provide a selected angular position of the intermediate structure 310 relative to the base structure 305.

[0109] The target device tracking controller 840 can be configured to track the target device 150 using the antenna boresight 111, which can be tracking while the tilt position controller 830 maintains (e.g., holds) the relative angle between the intermediate structure 310 and the base structure 305. In some examples, the target device tracking controller 840 can be configured to control a positioning system (e.g., antenna positioner 340) coupled to the intermediate structure 310, which is capable of orienting the antenna boresight 111 with respect to at least two angular degrees of freedom relative to the intermediate structure 310.

[0110] The target device tracking controller 840 can generate control signals for one or more antenna positioner drive elements based on preprogrammed instructions from, or other signals received from, the positioning axis controller 820 or the tilt position controller 830, feedback signals from one or more antenna positioner drive elements, or other instructions or signals received from outside the control system 810, such as encoder signals or any other signals. The target device tracking controller 840 can deliver commands or signals to the one or more antenna positioner drive elements regarding the magnitude and direction of movement of the antenna borehole 111 (e.g., to position the antenna positioner 340). The one or more antenna positioner drive elements can include power transistors for generating drive currents for one or more motors or other actuators from a power source according to the commands or signals to provide a selected borehole orientation, such as an orientation of the antenna borehole 111 about the first positioning axis 341 or the second positioning axis 342.

[0111] In some examples, the positioning axis controller 820, path finding component 850, tilt position controller 830, and target device tracking controller 840 may be separate devices or may be separate parts of an integrated control system 810. In other examples, the positioning axis controller 820, path finding component 850, tilt position controller 830, and target device tracking controller 840 may be integrated into the same component or module.

[0112] In some examples, control system 810 may also include an antenna signal feedback information measurement component, which may be configured to measure characteristics of the antenna signal at various locations, including identifying or estimating signal strength, interference, dropped data packets, etc. In some examples, the measured antenna signal feedback information may be sent to positioning axis controller 820 or another controller processor (e.g., tilt position controller 830, target device tracking controller 840) internal or external to control system 810. Additionally or alternatively, the measured signal feedback information may be used by the antenna signal feedback information measurement component.

[0113] The control system 810 includes a positioning axis controller 820, a tilt position controller 830, a target device tracking controller 840, and a path detection component 850, and may be implemented or performed using a processor, a digital signal processor (DSP), an ASIC, an FPGA, a state machine, or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. The processor may also be implemented as a combination of computing devices, such as a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

[0114] FIG. 9 shows a flowchart illustrating a method 900 for supporting antenna positioning with an off-axis tilt pointing mechanism according to an aspect of the present disclosure. The operations of method 900 may be performed by a system or components thereof, as described herein. For example, the operations of method 900 may be performed by antenna positioner 115, as described with reference to FIGS. 1-8. In some examples, a system (e.g., control system 810) may execute a set of instructions to control functional elements of antenna positioner 115 to perform the described functionality. Additionally or alternatively, the system may use dedicated hardware to perform aspects of the described functionality.

[0115] At 905, the system may determine a predicted path for the target device. The operations of 905 may be performed according to methods described herein. In some examples, aspects of the operations of 905 may be performed by a path detection component 850, as described with reference to FIG. 8.

[0116] At 910, the system can control an actuator based on the predicted path of the target device. The actuator can be coupled between a base structure and an intermediate structure rotatably coupled to the base structure about a first axis. The actuator can include a rotational element configured to rotate about a second axis and an eccentric element coupled to the rotational element and the intermediate structure. In some examples, controlling the actuator rotates the rotational element to set a first angle between the base structure and the intermediate structure about the first axis. The operations of 910 can be performed according to methods described herein. In some examples, aspects of the operations of 910 can be performed by tilt position controller 830, as described with reference to FIG. 8.

[0117] At 915, the system can use a positioning system coupled to the intermediate structure to track the target device with the antenna borehole while maintaining the first angle. In some examples, the positioning system can be configured to orient the antenna borehole with respect to at least two angular degrees of freedom relative to the intermediate structure. The operations of 915 can be performed according to methods described herein. In some examples, aspects of the operations of 915 can be performed by target device tracking controller 840, as described with reference to FIG. 8.

[0118] In some examples, the apparatus described herein can perform a method or methods, such as method 900. The apparatus can include features, means, or instructions (e.g., a non-transitory computer-readable medium storing instructions executable by a processor) for determining a predicted path of a target device, controlling an actuator based on the predicted path of the target device to set a first angle between a base structure and an intermediate structure rotatably coupled to the base structure about a first axis, and using a positioning system coupled to the intermediate structure to track the target device with an antenna borehole while maintaining the first angle. In some examples, an actuator is coupled between the base structures, and the actuator can include a rotating element configured to rotate about a second axis and an eccentric element coupled to the rotating element and the intermediate structure. In some examples, controlling the actuator rotates the rotating element. In some examples, the positioning system is configured to orient the antenna borehole with respect to at least two angular degrees of freedom relative to the intermediate structure.

[0119] Some examples of method 900 and the apparatus described herein may further include operations, features, means, or instructions for determining a second predicted path of another target device, controlling an actuator based on the second predicted path of the second target device, where the control maintains a first angle between the base structure and the intermediate structure about a first axis, and tracking the other target device with the antenna boresight while continuing to maintain the first angle using the positioning system. In various examples, the other target device may be the same as the target device or may be different from the target device.

[0120] In some examples of method 900 and the apparatus described herein, controlling includes an action, feature, means, or instruction for selecting a first angle from a set of a first angle and a second angle, or from some other set of discrete angles.

[0121] In some examples of the method 900 and apparatus described herein, the controlling may be based on the azimuth capabilities of the positioning system, the elevation capabilities of the positioning system, or a combination thereof.

[0122] In some examples of the method 900 and devices described herein, the controlling may be based on an angular deviation between one axis of at least two angular degrees of freedom and a predicted path of the target device that satisfies a threshold.

[0123] In some examples of the method 900 and the devices described herein, the controlling may be based on a predicted angular velocity of a positioning system associated with tracking the target device along a predicted path of the target device that satisfies a threshold.

[0124] In some examples of method 900 and the devices described herein, the controlling may be based on a predicted elevation angle of a positioning system associated with tracking a target device along a predicted path of the target device that satisfies a threshold.

[0125] In some examples of the method 900 and apparatus described herein, controlling may include actions, features, means, or instructions for rotating the rotating element until physical contact is achieved between the contact point of the intermediate structure and the contact point of the base structure.

[0126] In some examples of method 900 and the apparatus described herein, controlling may include an action, feature, means, or instruction for rotating a rotational element after physical contact is achieved between a contact point of the intermediate structure and a contact point of the base structure, where the rotation after physical contact is achieved preloads a compliant element between the actuator and one of the base structure or intermediate structure.

[0127] FIG. 10 shows a flowchart illustrating a method 1000 for supporting antenna positioning using a tilt pointing mechanism according to an aspect of the present disclosure. The operations of method 1000 may be performed by a system or components thereof, as described herein. For example, the operations of method 1000 may be performed by antenna positioning device 115, as described with reference to FIGS. 1-8. In some examples, a system (e.g., control system 810) may execute a set of instructions to control functional elements of the system to perform the described functions. Additionally or alternatively, the system may perform aspects of the described functions using dedicated hardware.

[0128] At 1005, the system may determine a predicted path for the target device. The operations of 1005 may be performed according to methods described herein. In some examples, aspects of the operations of 1005 may be performed by path detection component 850, as described with reference to FIG. 8.

[0129] At 1010, the system can control an actuator based on the predicted path of the target device. The actuator is coupled between a base structure and an intermediate structure that is rotatably coupled to the base structure about a first axis. In some examples, controlling the actuator sets a first angle between the base structure and the intermediate structure about the first axis. In some examples, the control includes actuation until physical contact is achieved between the connection point of the intermediate structure and the connection point of the base structure. In some examples, the control further includes actuation after physical contact is achieved between the connection point of the intermediate structure and the connection point of the base structure, which actuation can create or accumulate a preload in a compliant element between the actuator and one of the base structure or the intermediate structure. The operations of 1010 can be performed according to methods described herein. In some examples, aspects of the operations of 1010 can be performed by tilt position controller 830, as described with reference to FIG. 8.

[0130] At 1015, the system can use a positioning system coupled to the intermediate structure to track the target device with the antenna borehole while maintaining the first angle. In some examples, the positioning system can be configured to orient the antenna borehole with respect to at least two angular degrees of freedom relative to the intermediate structure. The operations of 1015 can be performed according to methods described herein. In some examples, aspects of the operations of 1015 can be performed by target device tracking controller 840, as described with reference to FIG. 8.

[0131] At 1020, the system may determine a second predicted path for the second target device. The operations of 1020 may be performed according to methods described herein. In some examples, aspects of the operations of 1020 may be performed by path detection component 850, as described with reference to FIG. 8.

[0132] At 1025, the system can control the actuator based on a second predicted path of the second target device, where the control maintains a first angle between the base structure and the intermediate structure about the first axis. In some examples, the control can maintain physical contact between the connection point of the intermediate structure and the connection point of the base structure. In some examples, the control can further include maintaining a preload of a compliant element between the actuator and one of the base structure or the intermediate structure. The operation of 1025 can be performed according to methods described herein. In some examples, aspects of the operation of 1025 can be performed by tilt position controller 830, as described with reference to FIG. 8.

[0133] At 1030, the system can use the positioning system to track the second target device using the antenna boresight while maintaining the first angle. The operations of 1030 can be performed according to methods described herein. In some examples, aspects of the operations of 1030 can be performed by target device tracking controller 840, as described with reference to FIG. 8.

[0134] It should be noted that the above-described methods illustrate possible implementations, and that the operations and steps may be rearranged or modified, and other implementations are possible. Furthermore, two or more methods may be combined.

[0135] Thus, methods 900 and 1000 can provide antenna positioning in systems that use multiple assembly antenna positioners. It should be noted that methods 900 and 1000 are considered exemplary implementations, and that the operations of methods 900 or 1000 can be rearranged or modified to enable other implementations. For example, aspects of two or more of methods 900 or 1000 can be combined.

[0136] The detailed description set forth above in connection with the accompanying drawings describes exemplary embodiments and does not necessarily represent the only embodiments that may be practiced or are within the scope of the claims. As used throughout this specification, the term "example" means "serving as an example, instance, or illustration" and does not mean "preferred" or "advantageous over other embodiments." The detailed description includes specific details for the purpose of providing an understanding of the described technology. However, these technologies can be practiced without these specific details. In some instances, well-known structures and devices are shown in block diagram form to avoid obscuring the concepts of the described embodiments.

[0137] The foregoing description and claims may refer to elements or features as being "connected" or "coupled" together. As used herein, unless expressly stated otherwise, "connected" means that one element / feature is directly or indirectly connected to another element / feature. Similarly, unless expressly stated otherwise, "coupled" means that one element / feature is directly or indirectly coupled to another element / feature.

[0138] As used herein, unless expressly stated otherwise, "rotationally coupled" refers to a coupling between objects that has a positional constraint between the objects at the coupling location and at least one rotational degree of freedom between the objects, where the at least one rotational degree of freedom is about at least one axis that passes through the coupling location. For example, objects may be rotationally coupled by any of a ball bearing, roller bearing, journal bearing, bushing, spherical bearing, ball-and-socket joint, etc. A description of objects as being "rotationally coupled" does not exclude a linear degree of freedom between the objects. For example, rotationally coupled objects may be coupled by a cylindrical journal bearing that provides a rotational degree of freedom about the axis of the cylinder as well as a linear degree of freedom along the axis of the cylinder. In such an example, the positional constraint between the objects would exist in a radial direction from the axis of the cylinder.

[0139] As used herein, unless expressly stated otherwise, "rigidly coupled" refers to a connection between objects that has no linear or rotational degrees of freedom between them. For example, objects may be rigidly coupled by any one or more of screws, bolts, clamps, magnets, or by processes such as welding, brazing, soldering, gluing, or fusing. A description of objects as "rigidly coupled" does not completely preclude movement between the objects. For example, rigidly coupled objects may have looseness or wear at the connection location that allows some movement between the objects. Furthermore, rigidly coupled objects may experience a degree of movement between the objects as a result of compatibility within or between the objects. Furthermore, two objects that are rigidly coupled may not be in direct contact; instead, there may be other components rigidly coupled between the two objects.

[0140] Thus, while the various schematic diagrams shown in the figures depict exemplary arrangements of elements and components, additional intervening elements, devices, features, or components may be present in an actual embodiment (provided the functionality of the illustrated circuitry is not adversely affected).

[0141] Information and signals may be represented using any of a variety of different technologies and techniques. For example, the data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

[0142] The functions described herein may be implemented in a variety of ways, using different materials, features, shapes, sizes, etc. Other examples and embodiments are within the scope of this disclosure and the appended claims. Also, features that implement a function may be physically located in various locations, including being distributed so that some of the functions are implemented in different physical locations. Also, as used herein, including the claims, "or" when used in a list of items (e.g., a list of items preceded by phrases such as "at least one of" or "one or more of") indicates a disjunctive list, so that, for example, "at least one of A, B, or C" means A or B or C, or AB or AC or BC, or ABC (i.e., A and B and C).

[0143] The previous description of the disclosure is provided to enable any person skilled in the art to make or use the disclosure. Various modifications to the disclosure will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other variations without departing from the scope of the disclosure. Thus, the disclosure is not intended to be limited to the examples and designs described herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A structure mounted on a base and configured to rotate about an axis of rotation, the structure including a contact point at a position different from the axis of rotation; a positioning system coupled to the structure and configured to track movement of an object moving along an object path in at least two angular degrees of freedom relative to the structure away from the axis of rotation; an actuator configured to rotate the structure about the axis of rotation; The actuator is a coupler coupled to the structure at a location offset from the axis of rotation; a drive element configured to move the coupler and change a relative angle between the structure and the base about the axis of rotation in response to movement of the coupler, wherein change in the relative angle between the structure and the base is limited to a first angle by physical contact between the contact point of the structure and the base. system.

2. The system of claim 1 , wherein the coupler is coupled to the structure via a compliant element.

3. 3. The system of claim 2, wherein the compliant element is configured to accumulate a preload based at least in part on the displacement of the drive element while a change in the relative angle between the structure and the base is limited to the first angle by physical contact between the contact point of the structure and the base.

4. 2. The system of claim 1, wherein a change in the relative angle between the structure and the base is limited to a second angle by physical contact between a second contact point on the structure, located differently from the contact point, and the base.

5. The system of claim 1 , further comprising a controller configured to control the actuator based at least in part on a predicted path of the object.

6. The controller The system of claim 5 , configured to determine whether to activate the drive element or hold the drive element based at least in part on the predicted portion of the object path.

7. The controller further comprises: holding the drive element so as to maintain physical contact between the contact point of the structure and the base; The system of claim 5 , further comprising controlling the positioning system to track movement of the object along the object path while maintaining physical contact between the contact points of the structure and the base.

8. The system of claim 1 , further comprising a controller configured to control the actuator based at least in part on a predicted position of a target relative to the system.

9. The positioning system includes: an elevation positioner; 10. The system of claim 1, further comprising: an azimuth positioner between the elevation positioner and the structure.

10. The system of claim 9 , wherein the elevation positioner is configured to track movement of the object along the object path about a positioning axis parallel to the rotation axis.

11. Align the mounted device with the target object, an elevation / azimuth positioning system configured to maintain alignment of the mounted device with the target object while tracking the target object as it moves along an object path, and to rotate the mounted device about an azimuth axis within a range of azimuth angles and an elevation axis within a range of elevation angles; a rotational positioning system coupled to the elevation / azimuth positioning system and configured to rotate the elevation / azimuth positioning system to a first position within a range of motion about a rotational axis independent of the azimuth axis and the elevation axis; the rotational positioning system is configured to rotate the elevation / azimuth positioning system based at least in part on the azimuth capability of the elevation / azimuth positioning system, the elevation capability of the elevation / azimuth positioning system, or a combination thereof. system.

12. The system of claim 11 , wherein the elevation / azimuth positioning system at the first location is configured to track the target object along the object path at an elevation positioning angle of less than 90 degrees.

13. The system of claim 11 , wherein the elevation / azimuth positioning system at the first location is configured to track the target object along the object path at an azimuth positioning angle less than 180 degrees.

14. 12. The system of claim 11, wherein a peak azimuth velocity associated with tracking the target object along the object path has a finite value based at least in part on the rotational positioning system rotating the elevation / azimuth positioning system to the first position.

15. The system of claim 11 , wherein the rotational positioning system is configured to maintain the rotation of the elevation / azimuth positioning system while the elevation / azimuth positioning system tracks the target object along the object path.

16. The system of claim 11 , wherein the rotational positioning system is configured to rotate the elevation / azimuth positioning system based at least in part on a predicted portion of the object path.

17. 12. The system of claim 11, wherein the rotational positioning system is configured to rotate the elevation / azimuth positioning system based at least in part on an angular deviation between an azimuth axis of the elevation / azimuth positioning system and a predicted portion of the object path.

18. The system of claim 11 , wherein the elevation axis of the elevation / azimuth positioning system is parallel to the rotation axis.

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