Patent Description:
In various applications, it may be desirable to track a star, planet, or other object as it moves across the sky during the course of a day. For example, solar light or radiation may be collected by directing one or more solar panels at the sun. While some solar panels are maintained as stationary objects, others may be configured to track the sun as it moves across the sky, so as to increase the quantity of sunlight or solar radiation collected. Traditional solar tracking mechanisms may operate with one or more axes of movement. Multiple axes of movement may, in some cases, be more efficient than a single axis of movement by allowing for more precise positioning. In some cases, solar panels may be moved on circular or rotational tracks in order to follow the sun's movement across the sky throughout a day. For example, some solar tracking mechanisms may operate with an altazimuth, or altitude/azimuth, motion system. An altazimuth motion system may provide for rotation about a vertical axis, such as a load bearing mast, and separate rotation about a horizontal axis.

Various methods and systems may be used to calculate a location of an object in the sky, such as the sun, at which to direct a device on the earth, such as a solar panel. Often, such systems and methods may be individually designed to operate at a particular location on the earth's surface. In some cases, for example, a system for tracking the sun's movement that is developed for use in the earth's Northern Hemisphere may not function as accurately in the Southern Hemisphere. In some embodiments, tracking mechanisms such as solar tracking mechanisms may track based on polar coordinates, or may use both latitudinal and longitudinal axes, for example. Moreover, some conventional tracking systems may use high cost motors such as digital servo motors to generate motion.

<CIT>discloses a tracking device for tracking the location of a moving object, comprising: two short axles; an upright portion; an arm portion comprising a lateral member and one or more connector arms, wherein the arm portion is coupled to the upright portion by a single axis support comprising a pivoted connection; a first linear actuation assembly causing the payload to rotate about the first axis of rotation; a second linear actuation assembly; and a control module configured to determine a position of a moving object in the sky based on a position of the tracking device on a surface of the Earth, the control module further configured to operate the first and second linear actuation assemblies to direct the payload relative to the moving object.

The following presents a simplified summary of one or more embodiments of the present disclosure in order to provide a basic understanding of such embodiments. This summary is not an extensive overview of all contemplated embodiments, and is intended to neither identify key or critical elements of all embodiments, nor delineate the scope of any or all embodiments.

The present invention relates to a tracking device for tracking the location of a moving object. The tracking device includes a spine portion for carrying a payload, a first linear actuation assembly causing the payload to rotate about a first axis of rotation, a second linear actuation assembly causing the payload to rotate about a second axis of rotation, and a control module comprising a Global Positioning System and configured to determine a position of a moving object in the sky based on a position of the tracking device on a surface of the Earth, the control module further configured to operate the first and second linear actuation assemblies to direct the payload relative to the moving object. In some embodiments, the first and second linear actuation assemblies may each include a linear actuator and a motor. In some embodiments, each linear actuation assembly may further include a linear absolute encoder. The second axis of rotation aligns with a longitudinal axis of the spine portion in the invention. The spine portion is supported by each connector arm by a connector that allows the spine to rotate. Further, the first axis of rotation is orthogonal to the second axis of rotation. In the invention, the tracking device also has an upright portion supporting the spine portion, an arm portion between the spine portion and upright portion, wherein the arm portion comprises a lateral member and one or more connector arms, and a single axis support coupling the spine portion to the upright portion. The first actuation assembly may be coupled to the upright portion and pivotably coupled to the arm portion. Likewise, the second actuation assembly may be coupled to the arm portion and pivotably coupled to the spine portion with a torque arm. The spine portion may remain static with respect to a third axis of rotation defined as a vertical axis aligned with the upright portion. In some embodiments, the tracking device may be configured for wireless communication.

Additionally, the present disclosure, in one or more embodiments, relates to a solar tracking device for tracking the location of the sun over a period of time. The solar tracking device has a spine portion carrying at least one of a solar panel, a solar concentrator, and a heliostat. The tracking device has a first linear actuation assembly causing the one or more solar panels to rotate about a first axis of rotation, a second linear actuation assembly causing the one or more solar panels to rotate about a second axis of rotation, and a control module. The control module may be configured to receive Global Positioning System data comprising the tracking device's location, the time, and the date. The control module is further configured to determine the location of the sun based on the Global Positioning System data, and direct the first and second actuation assemblies to position the one or more solar panels such that the one or more solar panels are directed relative to the sun. In some embodiments, the first and second linear actuation assemblies may each have a linear actuator and a motor. In some embodiments, the first and second linear actuation assemblies may each have a linear absolute encoder. In the invention, the second axis of rotation aligns with a longitudinal axis of the spine portion, and the first axis of rotation is orthogonal to the second axis of rotation. The tracking device further has an upright portion supporting the spine portion, an arm portion between the spine portion and the upright portion, and a single axis support coupling the arm portion to the upright portion. The first actuation assembly may be coupled to the upright portion and pivotably coupled to the arm portion. Similarly, the second actuation assembly may be coupled to the arm portion and pivotably coupled to the torque arm. The spine portion may have a first end and a second end. In some embodiments, the first end may be directed North and the second end may be directed South. In some embodiments, the tracking device may be configured for wireless communication. In some embodiments, directing the first and second actuation assemblies may include referenecing an error correction lookup table.

Additionally, in one or more embodiments, not part of the present invention, the present disclosure relates to a method for directing a payload relative to a moving object. The method may include the steps of receiving Global Positioning System data related to the time, date, and location of a tracking device, determining an azimuth and altitude of the moving object with respect to the tracking device, calculating a first angular motion path corresponding to a first axis of rotation of the payload and a second angular motion path corresponding to a second axis of rotation of the payload, calculating a first linear motion path and a second linear motion path from the first and second angular motion paths, and directing the device to rotate the payload in accordance with the first and second linear motion paths. In some embodiments, not part of the present invention, the method may be repeated at timed intervals over the course of a day. In some embodiments, not part of the present invention, the method may further include calculating an error correction for the first linear motion path and the second linear motion path. The error correction may be determined by referencing an error correction lookup table and using bicubic interpolation to interpolate the error correction.

Additionally, in one or more embodiments, the present disclosure relates to a tower structure having a tracking device for tracking the location of a moving object. The tracking device includes a spine portion for carrying a payload, a first linear actuation assembly causing the payload to rotate about a first axis of rotation, a second linear actuation assembly causing the payload to rotate about a second axis of rotation, and a control module configured to determine a position of a moving object in the sky. The control module is further configured to operate the first and second linear actuation assemblies to direct the payload relative to the moving object. In some embodiments, the tower structure may be a communication tower or a solar power tower. Where the tower structure is a solar power tower, the payload may include a heliostat in some embodiments.

While the specification concludes with claims particularly pointing out and distinctly claiming the subject matter that is regarded as forming the various embodiments of the present disclosure, it is believed that the invention will be better understood from the following description taken in conjunction with the accompanying Figures, in which:.

The present invention, relates to a device for tracking movement of an object in space. The present invention relates to a device for tracking an object's movement across the sky, based on Global Positioning System (GPS) information. The tracking device functions through the use of two linear actuation assemblies. The tracking device is generally configured to accurately track the location of the sun, or another object in space, from any location on the earth, such that the tracking device directs a payload, such as solar panels, solar concentrators, or heliostats toward the object or at an angle relative to the object. In some embodiments, the tracking device may call for a relatively low power consumption. In some embodiments, the tracking device may have a wireless device such as a Zigbee radio to allow for wireless communication.

Turning now to <FIG>, a dual axis tracking device <NUM> is shown. The tracking device <NUM> is generally configured to track the location of an object in space, such as the sun, such that the device may direct a payload <NUM>, such as solar panels, toward the object or at an angle relative to the object. The tracking device <NUM> may track the location of the object over the course of a day or night, for example, as the object moves across the sky, such that the device may substantially continuously direct its payload <NUM> at the appropriate angle.

<FIG> illustrates the tracking device <NUM> that supports and directs the payload <NUM>. The tracking device <NUM> may have a base <NUM>, and has an upright portion <NUM>, an arm portion <NUM>, a spine portion <NUM>, a first actuation assembly <NUM>, and a second actuation assembly <NUM>.

The upright portion <NUM> may generally support the weight of the tracking device <NUM> and any payload <NUM> the device may be carrying such as solar panels. The upright portion <NUM> may support the tracking device <NUM> high enough off of the ground surface so as to allow for a full range of movement of the payload <NUM> by the first <NUM> and second <NUM> actuation assemblies. In some embodiments, the upright portion <NUM> may generally be constructed of steel, aluminum, or other metals or metal alloys. In other embodiments, the upright portion <NUM> may be constructed of one or more plastics such as PVC, concrete, or any other suitable material. The upright portion <NUM> may generally have any suitable length. The upright portion <NUM> may have a rounded cross section as shown in <FIG>, in some embodiments. In other embodiments, the upright portion <NUM> may have any suitable cross sectional shape. The upright portion <NUM> may have any suitable width or diameter. The upright portion <NUM> may connect with or to the ground surface via a base <NUM>.

With continued reference to <FIG>, the base <NUM> may provide lateral support for the upright portion <NUM>. The base <NUM> may include a foot <NUM> and one or more angular supports <NUM>. In some embodiments, the tracking device <NUM> may be positioned on the ground surface. In other embodiments, the tracking device <NUM> may be positioned on a foundation, such as a concrete foundation, or other surface. The foot <NUM> may be positioned between the upright portion <NUM> and ground surface, foundation, or other surface. The foot <NUM> may have a width or diameter that is larger than that of the upright portion <NUM>, so as to provide lateral support to the upright portion. In some embodiments, the foot <NUM> may be bolted or otherwise coupled to the ground, foundation, or other surface. In other embodiments, the foot <NUM> may be positioned on the ground, foundation, or other surface without a coupling mechanism. Where the foot <NUM> is not bolted or otherwise coupled to the ground, foundation, or other surface, the foot may have a relatively large width or diameter, compared to the upright portion <NUM>. However, where the foot <NUM> is bolted or otherwise coupled to the ground, foundation, or other surface, the foot may have a relatively smaller width or diameter, in some embodiments. In other embodiments, the foot <NUM> may have any suitable width or diameter. As shown in <FIG>, in some embodiments, the foot <NUM> may have a circular shape. In other embodiments, the foot <NUM> may have any suitable shape. The foot <NUM> may generally have any suitable thickness. One or more angular supports <NUM> may strengthen the connection between the foot <NUM> and the upright portion <NUM>. The one or more angular supports <NUM> may have any suitable thickness. In some embodiments, the base <NUM> may be constructed of steel, aluminum, or other metals or metal alloys. In other embodiments, the base <NUM> may be constructed of one or more plastics such as PVC, concrete, or any other suitable material.

With continued reference to <FIG>, an arm portion <NUM> couples to the upright portion <NUM> to provide rotational support to the spine portion <NUM>. The arm portion <NUM> has a lateral member <NUM> and one or more connector arms <NUM>. In some embodiments, the lateral member <NUM> may be positioned parallel to the spine portion <NUM>. In some embodiments, the lateral member <NUM> may have a length that is longer, shorter, or the same as the length of the spine portion <NUM>. Generally, the lateral member <NUM> may have a length sufficient to provide enough support for the length of the spine portion <NUM>, and the length of the lateral member may thus be proportion to the length of the spine portion. The one or more connector arms <NUM> may extend perpendicular from the lateral member <NUM> to connect to the spine portion <NUM>. In some embodiments, as shown in <FIG>, the arm portion <NUM> may have one connector arm <NUM> at each end of the lateral member <NUM>. In other embodiments, the arm portion <NUM> may have any suitable number of connector arms <NUM>. Each connector arm <NUM> couples to the spine portion <NUM> via a connector <NUM>. The connector <NUM> may be or include a clamp, bolts, screws, or any suitable coupling mechanism. According to the invention, the connector <NUM> allows the spine portion <NUM> to rotate or twist. In some embodiments, not part of the invention, the spine portion <NUM> may connect directly to the lateral member <NUM>. For example, in some embodiments, not part of the invention, the spine portion <NUM> may pass through an opening in the lateral member <NUM>. The lateral member <NUM> and connector arms <NUM> may have any suitable cross sectional shape, such as a rectangular shape for example. The arm portion <NUM> may be constructed of steel, aluminum, or other metals or metal alloys. In other embodiments, the arm portion <NUM> may be constructed of one or more plastics such as PVC, or any other suitable material.

In the invention, the arm portion <NUM> couples to the upright portion <NUM> by a single axis support <NUM>. The single axis support <NUM> comprises a pivoted connection and may provide for rotational movement about one or more axes, and in some cases two axes. According to the invention, the single axis support <NUM> may allow for the arm portion <NUM> to rotate about a first axis of rotation <NUM>, which may be perpendicular to a longitudinal axis of the lateral member <NUM>, and a second axis of rotation <NUM> orthogonal to the first axis. The first and second axes of rotation <NUM>, <NUM> may each pass through the connection point between the arm portion <NUM> and the upright portion <NUM>. In some embodiments, not part of the invention, the spine portion <NUM> may connect directly to the upright portion <NUM> via the single axis support <NUM>.

With continued reference to <FIG>, the spine portion <NUM> provides support and/or alignment for a payload <NUM> held by the tracking device <NUM>. For example, the device may carry one or more solar panels, in which the spine portion <NUM> provides a base for supporting and/or aligning the one or more solar panels. In this way, as the object is tracked across the sky, the spine portion <NUM> serves to align the payload <NUM> with the object or with a point relative to the object. The spine portion <NUM> may be any suitable length and width or diameter so as to provide sufficient support to the payload <NUM>. The spine portion <NUM> may have any suitable cross sectional shape, such as a circular shape for example. The spine portion <NUM> may be constructed of steel, aluminum, or other metals or metal alloys. In other embodiments, the spine portion <NUM> may be constructed of one or more plastics such as PVC, or any other suitable material.

With continued reference to <FIG>, the tracking device <NUM> may have two or more actuation assemblies that facilitate movement of the device. Generally, two or more actuation assemblies facilitate movement of the arm portion <NUM>, spine portion <NUM>, and/or payload <NUM> with respect to the upright portion <NUM> and base <NUM>. In the invention, the tracking device <NUM> has a first actuation assembly <NUM> and a second actuation assembly <NUM>.

The first actuation assembly <NUM> may, in some embodiments, be positioned between the upright portion <NUM> and the arm portion <NUM>. In other embodiments, the first actuation assembly <NUM> may be positioned between the spine portion <NUM> and the upright portion <NUM>, or between the arm portion <NUM> and spine portion <NUM>, for example. Other positioning arrangements of the first actuation assembly <NUM> are contemplated as well. The first actuation assembly <NUM> may facilitate movement of the arm portion <NUM>, spine portion <NUM>, and/or payload <NUM> with respect to the upright portion <NUM> and base <NUM> about a horizontal axis. The first actuation assembly <NUM> may couple to the upright portion <NUM> and arm portion <NUM> using clamps, bolts, screws, or any suitable coupling mechanism. In some embodiments, the first actuation assembly <NUM> may couple to the upright portion <NUM> and/or arm portion <NUM> with a pivoted, hinged, or other movable connection.

In some embodiments, the second actuation assembly <NUM> may be positioned between the arm portion <NUM> and the spine portion <NUM>. In other embodiments, the second actuation assembly <NUM> may be positioned between the arm portion <NUM> and the upright portion <NUM>, or between the spine portion <NUM> and the upright portion <NUM>, for example. Other positioning arrangements of the second actuation assembly <NUM> is contemplated as well. The second actuation assembly <NUM> may facilitate movement of the arm portion <NUM>, spine portion <NUM>, and/or payload <NUM> with respect to the upright portion <NUM> and base <NUM> about the longitudinal axis of the spine. The second actuation assembly <NUM> may couple to the upright arm portion <NUM> and spine portion <NUM> using clamps, bolts, screws, or any suitable coupling mechanism. In some embodiments, the second actuation assembly <NUM> may couple to the arm portion <NUM> and/or spine portion <NUM> with a pivoted, hinged, or other movable connection.

Using the first and second actuation assemblies <NUM>, <NUM>, the tracking device <NUM> operates to position the spine portion <NUM> to direct a payload <NUM> toward or relative to a moving object, such as the sun. In this regard, the first actuation assembly <NUM> provides for movement of the arm portion <NUM>, spine portion <NUM>, and payload <NUM> about a first axis of rotation <NUM>, as shown in <FIG>. The first axis of rotation <NUM> is perpendicular to a longitudinal axis of the spine portion <NUM> and may be generally horizontal. Additionally, in the invention, the second actuation assembly <NUM> provides for movement of the payload <NUM> about a second axis of rotation <NUM>, which is the longitudinal axis of the spine. The two axes of rotation <NUM>, <NUM> allow for the tracking device <NUM> to direct its payload <NUM> at a moving object across the sky, in the invention, while the longitudinal axis of the spine portion <NUM> remains statically pointed in a direction. That is, where a third axis <NUM> aligns with the upright portion <NUM>, the longitudinal axis of the spine portion <NUM> may remain fixed with respect to rotation about the third axis. For example, where the longitudinal axis of the spine portion <NUM> is directed North and South, the third axis <NUM> and rotation about the third axis may be static such that the longitudinal axis of the spine portion may continuously point North and South while movement about the first and second axes <NUM>, <NUM> occurs.

<FIG> illustrates the first actuation assembly <NUM>. The first actuation assembly <NUM> may rotate the arm portion <NUM>, spine portion <NUM>, and/or payload <NUM> about the first axis of rotation <NUM> with two pivot points <NUM>, <NUM>. The first pivot point <NUM> may be located where the first actuation assembly <NUM> couples to the arm portion <NUM>. The second pivot point <NUM> may be located where the arm portion <NUM> connects to the upright portion <NUM> via the single axis support <NUM>. The first actuation assembly may comprise a linear actuator <NUM>, such as a linear slide, and a motor <NUM> that drives the linear actuator. A sliding element of the linear actuator <NUM> may couple to the upright portion <NUM> with a fixed connection. In this way, as the motor <NUM> drives movement along the linear actuator <NUM>, the arm portion <NUM>, spine portion <NUM>, and/or payload <NUM> may pivot about the first and second pivot points <NUM>, <NUM>, and be rotated about the first axis of rotation <NUM>. It may be appreciated that the orientation of the linear actuator <NUM> may be reversed in some embodiments, such that the sliding element may couple to the arm portion <NUM> and a pivot point may be located at the connection between the first actuation assembly <NUM> and the upright portion <NUM>. The linear actuator <NUM> may have any suitable length and range of motion in various embodiments. In some embodiments, the length may depend on where along the arm portion <NUM> and upright portion <NUM> the first actuation assembly <NUM> connects, and may further depend on the range of motion provided about the first axis of rotation <NUM>.

The motor <NUM> may be a relatively inexpensive motor in some embodiments. For example, the motor <NUM> may be a low cost stepper motor. In other embodiments, a DC motor or servo motor may be used. In other embodiments, the motor <NUM> may be any suitable motor. The motor <NUM> may rotate a gear screw or lead screw, for example, with each step. The gear screw or lead screw may operate to drive the sliding element along the linear actuator <NUM>. In this way, the gear screw or lead screw may translate the rotational motion of the motor <NUM> into linear motion of the linear actuator <NUM>. In some embodiments, the gear screw or lead screw may couple to a gearbox, which may operate to drive the sliding element along the linear actuator <NUM>. The gearbox may provide for additional torque to the linear actuator <NUM> in some embodiments. A gearbox may include one or more gears arranged in any suitable configuration. In some embodiments, a planetary gearbox may be used. In other embodiments, any suitable gearbox may be used to assist with moving the sliding element along the linear actuator <NUM>. In some embodiments, any suitable gear reduction of the gearbox may be used to increase the motor and gearbox output torque.

In some embodiments, the motor <NUM>, linear actuator <NUM>, and/or other components may be configured for use in harsh conditions or otherwise outdoor use. For example, mechanical components may be configured to operate without lubricating agents. In some embodiments, for example, the gear screw or lead screw may connect to the linear actuator <NUM> with a plastic bearing or other element that may function without lubrication, such as for example an IGUS DRYLIN bearing or other device to assist with movement. In some embodiments, the gear screw or lead screw or one or more other components may be constructed of a material such as that used in the IGUS DRYLIN devices. In other embodiments, similar materials or any suitable material may be used to provide for operation without lubricating agents.

<FIG> illustrates the second actuation assembly <NUM>. The second actuation assembly <NUM> twists the spine portion <NUM> so as to rotate the payload <NUM> about the second axis of rotation <NUM>. Like the first actuation assembly <NUM>, the second actuation assembly <NUM> may comprise a linear actuator <NUM> and a motor <NUM> that drives the linear actuator. The second actuation assembly <NUM> may further comprise a torque arm <NUM> in some embodiments. The torque arm may connect the linear actuator to the spine portion <NUM>. The second actuation assembly may connect to the upright portion <NUM> with a fixed connection, in some embodiments. In this way, the second actuation assembly <NUM> may rotate the spine portion <NUM> and/or payload <NUM> about the second axis of rotation <NUM> with two pivot points <NUM>, <NUM>. The first pivot point <NUM> may be located where the second actuation assembly <NUM> couples to the torque arm <NUM>. The second pivot point <NUM> may be located where the torque arm <NUM> couples to the spine portion <NUM>. A sliding element of the linear actuator <NUM> may couple to the upright portion <NUM> with a fixed connection. In this way, as the motor <NUM> drives movement along the linear actuator <NUM>, the spine portion <NUM> and/or payload <NUM> may pivot about the first and second pivot points <NUM>, <NUM>, and be rotated about the second axis of rotation <NUM>. It may be appreciated that the orientation of the linear actuator <NUM> may be reversed in some embodiments, such that the sliding element may couple to the spine portion <NUM> and a pivot point may be located at the connection between the second actuation assembly <NUM> and the upright portion <NUM>. The linear actuator <NUM> may have any suitable length and range of motion in various embodiments. In some embodiments, the length may depend on where along the spine portion <NUM> and upright portion <NUM> the second actuation assembly <NUM> connects, and may further depend on the range of motion provided about the second axis of rotation <NUM>.

Like motor <NUM> of the first actuation assembly <NUM>, the motor <NUM> of the second actuation assembly <NUM> may be a relatively inexpensive motor in some embodiments. For example, the motor <NUM> may be a low cost stepper motor. In other embodiments, a DC motor or servo motor may be used. In other embodiments, the motor <NUM> may be any suitable motor. The motor <NUM> may rotate a gear screw or lead screw, for example, with each step. The gear screw or lead screw may operate to drive the sliding element along the linear actuator <NUM>. In this way, gear screw or lead screw may translate the rotational motion of the motor <NUM> into linear motion of the linear actuator <NUM>. As with motor <NUM>, in some embodiments, the gear screw or lead screw may couple to a gearbox, which may operate to drive the sliding element along the linear actuator <NUM>. The gearbox may provide for additional torque to the linear actuator <NUM> in some embodiments. A gearbox may include one or more gears arranged in any suitable configuration. In some embodiments, a planetary gearbox may be used. In other embodiments, any suitable gearbox may be used to assist with moving the sliding element along the linear actuator <NUM>. In some embodiments, any suitable gear reduction of the gearbox may be used to increase the motor and gearbox output torque.

In some embodiments, the tracking device <NUM> may be connected to a power source. The power source may operate the motors <NUM>, <NUM> of the first and second actuation assemblies <NUM>, <NUM>. The power source may consist of AC and/or DC power, such as battery power, or other power sources in some embodiments. The power source may additionally power a control module in some embodiments.

In the invention, the tracking device <NUM> is connected to a control module. The control module may consist of hardware and/or software components. The control module may be connected to the motors <NUM>, <NUM> in some embodiments. In the invention, the control module determines an approximate position of an object moving across the sky, such as the sun. The control module includes a GPS system in the invention, which may include hardware and/or software, such that the control module can determine where on the earth it is located and the local time of day and date. The control module may use hardware and/or software to determine the position of an object in space, such as the sun, from the GPS information. For example, the control module may be configured to determine the azimuth and altitude of the sun from the location of the tracking device <NUM>, as discussed more fully below. The control module may additionally or alternatively be configured to send instructions to the motors <NUM>, <NUM> to drive the first and second actuation assemblies <NUM>, <NUM>. For example, the control module may instruct the motors <NUM>, <NUM> to position the payload <NUM> to be directed toward or relative to the moving object, such as the sun. In some embodiments, the control module may include any or all of the elements shown in <FIG>. It should be understood that the particular elements shown in <FIG> are illustrated as examples. In other embodiments, the control module may include elements similar or related to those shown in <FIG> or other elements not depicted in <FIG>.

In use, the tracking device operates to track the location of an object and direct the payload toward or relative to that object. For example, in some embodiments, the tracking device may use GPS information to determine the location of the device, and from that information, the location of the sun. For example, the tracking device may use such GPS information as a triangulated location, time, and date to determine an altitude and azimuth of an object in space, such as the sun. The tracking device operates to direct its payload, such as one or more solar panels, toward the determined location of the object in space by way of the first and second actuation assemblies. In other embodiments, not part of the invention, the tracking device may operate to direct its payload toward a location or object relative to the determined location of the object ins pace by way of the first and second actuation assemblies. Various algorithms may be used to determine an altitude and azimuth based on GPS information. Once the azimuth and altitude are known, the location can be converted into a first motion path, performed by the first actuation assembly, and a second motion path, performed by the second actuation assembly. <FIG> illustrates a method <NUM>, not part of the present invention, that the tracking device may perform. The method may include a calibration step (<NUM>), receiving GPS information (<NUM>), determining location of the object in space, such as the sun (<NUM>), determining positioning of the device (<NUM>), and positioning the device (<NUM>).

The device may perform a calibration step (<NUM>). In some embodiments, the calibration step may be performed automatically. For example, the calibration step may be performed automatically when the tracking device initially powers on at a location. The calibration may be performed based on some user input. The calibration step may be performed partially or entirely manually. The calibration step may include determining one or more assumptions. That is, the tracking device may operate, at least in part, based on one or more assumptions. For example, an assumption may be that the longitudinal axis of the spine portion <NUM> is directed North at one end and directed South at an opposing end. Such assumptions may provide for more accurate positioning of the spine portion and/or payload. Based on these assumptions, the tracking device may be used to track the location of an object from any location on the earth's surface. A correct assumption (such as a first end of the longitudinal axis of the spinal portion is directed North in the Northern Hemisphere) may allow the tracking device to accurately track the location of a moving object and direct its payload accordingly. In this way, it may be appreciated that the tracking device may be able to track the location of an object from any location on the earth's surface merely by changing the assumption(s). For example, an assumption in the Northern Hemisphere may be that a first end of the spinal portion is directed North. For operation in the Southern Hemisphere, the assumption may be changed to reflect that the first end of the spinal portion is directed South.

The calibration step (<NUM>) may additionally or alternatively include homing the first and second actuation assemblies. Homing an actuation assembly may include operating the motor, such as a stepper motor, to one end of travel until the motor reaches a limit switch, such as an electromechanical limit switch, defining a limit of travel for the linear actuator. The tracking device may register the point of the limit switch as a zero point of motion of the actuation assembly. Positioning of the device may then be determined based on the zero points of motion for each actuation assembly. This may allow the control module to more accurately determine the relationship between the motor operation and the positioning of the spine portion and/or payload. Once the calibration step is completed, the tracking device may be able to power off and on without the need for recalibration. The tracking device may know its position each time it turns on after calibration because the actuation assemblies may have a zero back drive. That is, each actuation assembly may have sufficient forces preventing the linear actuator and/or drive screw or lead screw from moving without the motor drive enabled. Where for example the motors are stepper motors, the motors may additionally or alternatively help to prevent the linear actuators and/or drive screws or lead screws from moving during shut off. Further, the gearbox may additionally or alternatively help to prevent the linear actuators and/or drive screws or lead screws from moving during shut off.

A device such as a rotary encoder or linear absolute encoder may be used to determine a position of the linear actuator with respect to the motor operation. A linear absolute encoder or other similar device may provide a location of the linear actuator to the tracking device, such that the tracking device may know the position of the linear actuator with respect to the motor. In this way, the linear absolute encoder may, at least in part, reduce or obviate the need for homing an actuation assembly. For example, the linear absolute encoder may provide a position of a linear actuator when the tracking device powers on, when the device begins a tracking routine, at the request of the tracking device or a user, and/or at any other suitable time. Each actuation assembly may operate using a linear absolute encoder. The use of one or more linear absolute encoders or similar device may allow the tracking device to correct for any intentional or unintentional movement of the actuation assemblies that may occur during power shut offs or between tracking routines, for example.

As shown in <FIG>, the tracking device may receive GPS information (<NUM>). The GPS information may be received at the tracking device from a source. For example, the GPS information may be sent to the tracking device over a wired or wireless network. The device may have GPS hardware and/or software, as discussed above, and may determine the GPS information internally using, for example, data transmitted by a GPS satellite constellation and received by onboard GPS antenna and hardware. GPS information may include location information such as triangulated coordinates, date, and time, each related to the tracking device's current location. Using the GPS information, the tracking device may determine its exact or approximate location on the surface of the earth.

Based on the received GPS information, the tracking device may determine the location of a moving object in space, such as the sun (<NUM>). For example, the tracking device may determine an azimuth and altitude of an object in relation to the device's position. Where the moving object is the sun, the azimuth and altitude may be calculated from the GPS information based on a Solar Position Algorithm, provided by the U. Department of Energy, for example. Other calculations or methods may be used to determine the azimuth and altitude of an object or other location information. <FIG> graphically illustrates the location of an azimuth <NUM> and altitude <NUM> in relation to a location <NUM> of an object in space, such as the sun, and the location <NUM> of the tracking device <NUM>. Both locations <NUM>, <NUM> are shown in relation to North, South, East, and West directions and in relation to a vertical Z axis. The azimuth <NUM> and altitude <NUM> combine to provide the location vector <NUM> of the sun or other object. <FIG> graphically illustrates the angle of the first motion path M1, related to the first actuation assembly <NUM>, and the angle of the second motion path M2, related to the second actuation assembly <NUM>. <FIG> graphically illustrates the variables used to calculate the angles of the first motion path M1 and the second motion path M2, according to some embodiments. The angles of the motion paths M1, M2 may be calculated by the following:
<MAT>
<MAT>
<MAT>
<MAT>
<MAT>
<MAT>
<MAT>.

Other equations, calculations, or other methods may be used to determine the angles of the motion paths M1, M2. For example, the calculation of M2 (i.e., the day axis angle) may be adjusted to accommodate the reference angle established by M1 (i.e., the season axis angle). This may be performed by transforming the M2 back to an offset cylindrical coordinate system based on M1. This transform would allow for higher accuracy at higher latitudes. Accordingly, by using a trigonometric transform to transform M2 back to an offset cylindrical coordinate system based on M1 and then calculating the M2 angle, the effect on M2 results in higher accuracy across a range of latitudes and seasons.

With continued reference to <FIG>, from the angles of the motion paths M1, M2, the tracking device may determine where to direct the spine portion and/or payload, such that they are directed toward the object (<NUM>). For example, the tracking device may determine a linear distance for each actuation assembly <NUM>, <NUM> to direct the spine portion and/or payload toward the object. <FIG> graphically illustrates the variables used to calculate the first linear motion b3. The first linear motion b3 may be calculated by the following:
<MAT>
<MAT>
<MAT>
<MAT>
<MAT>.

<FIG> illustrates the locations of the torque arm length b2 and the pivot support length b1 in relation to the first actuation assembly <NUM>. The first linear motion b3 may be determined using other equations, calculations, or method.

Graphically illustrates the variables used to calculate the second linear motion c2. The second linear motion c2 may be calculated by the following:
<MAT>
<MAT>
<MAT>
<MAT>
<MAT>.

<FIG> illustrates the locations of the torque arm length c1 and the pivot support length c3 in relation to the second actuation assembly <NUM>. The second linear motion c2 may be determined using other equations, calculations, or methods. It may be appreciated that the tracking device <NUM> may determine a direction for the payload by means other than linear motion. For example, the tracking device may angle the spine portion and/or payload from the ground surface, based on the first and second motion paths M1, M2.

It may be appreciated that the tracking device may be configured to direct its payload at an angle relative to the object moving across the sky. For example, the payload may be a heliostat or similar device having a mirror or other reflective surface. The mirror or other reflective surface may be directed at an angle relative to the sun's location, such that it may reflect the sunlight toward another point which may be a stationary point. In such cases, the first and second linear motions may be calculated differently than above. That is, after determining the sun's azimuth and altitude, the tracking device may determine the first and second linear motions based on the location of the sun in the sky and an angle between the sun's location and the location of the point onto which the sunlight is to be reflected. Generally, the tracking device may be configured to direct its payload at any angle relative to the moving object's location. In this way, it may be appreciated that the tracking device may receive instructions to direct the payload toward generally any vector which may or may not depend on the location of the object being tracked. The instructions may be received locally or remotely over a wired or wireless network. The positioning of the tracking device may be fully controlled remotely.

With the first and second linear motions b3, c2, the tracking device may instruct the motors to position the actuation assemblies so as to direct the payload toward the moving object or toward a different position (<NUM>). Where the motors are stepper motors, for example, the tracking device may determine a number of steps to operate on each motor, so as rotate the payload about the first and second axes of rotation <NUM>, <NUM> to a desired position.

The tracking device may repeat steps <NUM> through <NUM> intermittently or continuously. For example, the tracking device may operate continuously to determine the location of the object in space and continuously update the device's positioning. The tracking device may determine the object's location and reposition the device at intervals. For example, the tracking device may recalculate location and position every hour. The tracking device may recalculate location and position every <NUM>-<NUM> minutes. The tracking device may recalculate location and position every <NUM>-<NUM> minutes in some embodiments. Particularly, the tracking device may recalculate location and position every <NUM>-<NUM> minutes. In this way, the device may take advantage of an object's relatively slow movement across the sky during the course of a day or night. For example, the location of the sun, may not move very far relative to the device over the course of a <NUM>-<NUM> minute interval. The system may update location and position at different intervals. In this way, for example where the device is directing a payload of solar panels at the sun, the device may be able to recalculate intermittently without substantial solar collection efficiency loss. In addition, the ability to operate intermittently may allow the device to operate with relatively low power consumption. A low power timer may operate to power the device on at intervals and then the device may power off after adjusting. The process of determining the sun's location and repositioning the device may be a relatively fast process, such that the device does not require much power when it powers on at intervals. For example, over a twelve hour period of tracking the sun across the sky, the device may be powered off approximately <NUM>% of the time.

The tracking device may reference a calibration lookup table automatically or manually for purposes of error correction. A calibration lookup table may include a plurality of angles or motion paths relating to directing the payload and corresponding correction angles or correction paths, for example. That is, the lookup table may include error corrections to be performed by the first and/or second actuation assemblies for various calculated motion paths, angles, or object locations. The error corrections of the lookup table may allow the device to correct for various sources of error inherent in or otherwise found in the device. For example, error may be introduced by small inconsistencies in machining, motion of the linear actuator in response to each motor step, small calculation inaccuracies, which may relate to index of refraction of the atmosphere or other atmospheric conditions for example, and/or other sources of error. The lookup table may include a plurality of calculated positions or other calculations as performed by the tracking device, along with corresponding error corrections. The lookup table may be determined based on actual device calculations performed over time, such as over the course of a day, month, or year, for example. The corresponding error corrections may be determined automatically or manually. Likewise, the lookup table may be populated automatically or manually. The error corrections may be determined and/or populated in the lookup table using an application such as a mobile phone application. In some embodiments, error corrections may be determined for a limited number of location or position calculations, or for a period of time such as a day, for example, and additional error corrections may be extrapolated. Such calculations and extrapolations may be performed remotely using an application, such as a mobile phone or computer application. An error correction lookup table or a portion thereof may be directly sent or supplied to the tracking device. The tracking device may be automatically or manually directed to reference the lookup table periodically, such as after each location and position recalculation. Where a required error correction is not found on the lookup table for a particular calculated location, direction, or motion, bicubic interpolation or another interpolation method may be used to interpolate the needed error correction between two similar correction errors found in the lookup table.

<FIG> illustrates a method <NUM> for populating a lookup table with error corrections. As shown, the tracking device may receive GPS information (<NUM>), determine a location of the moving object (<NUM>), and determine a linear motion needed to direct the payload (<NUM>), as described above with respect to method <NUM>. Additionally, an error correction for the linear motion may be determined (<NUM>). The error correction may be determined automatically or manually, such as through the use of a mobile phone application or other application, locally or remotely. A lookup table may be populated with the determined error correction (<NUM>). In some embodiments, steps <NUM> through <NUM> may be repeated until a plurality of data points are populated in the lookup table. Additional error corrections may be extrapolated to expand the lookup table (<NUM>). Various extrapolation methods may be used.

<FIG> illustrates a method <NUM>, not part of the invention, that the tracking device may perform in order to position the payload with consideration of the lookup table error corrections. As shown, the method <NUM> may include a calibration step (<NUM>), receiving GPS information (<NUM>), determining a location of a moving object (<NUM>), and determining a linear motion needed to direct the payload (<NUM>), as described above with respect to method <NUM>. Additionally, the method <NUM> may include referencing an error correction lookup table (<NUM>). The tracking device may be directed automatically or manually to reference the lookup table. Additionally, where needed, for example if the particular location or positioning does not fall within the error correction lookup table, the tracking device may interpolate an error correction (<NUM>). Generally, any suitable interpolation method may be used, and bicubic interpolation may be employed. Taking into account the error correction, the tracking device may direct its payload (<NUM>) using one or more actuation assemblies. Steps <NUM> through <NUM> may be repeated intermittently or continuously, as described above in order to recalculate location of the tracked object and positioning of the tracking device.

It may be appreciated that the first and second actuation assemblies may relate generally to a season axis and a day axis. That is, the first actuation assembly, first axis of rotation, and first linear motion may be related to a seasonal position of the object being tracked. For example where the object being tracked is the sun, the sun's location may depend in part on the time of year. The positioning of the first actuation assembly may correlate with the sun's location during a particular time of year. Similarly, it may be appreciated that the second actuation assembly, second axis of rotation, and second linear motion may be related to a daily position of the object being tracked. For example where the object being tracked is the sun, the sun's location may depend in part on the time of day. The positioning of the second actuation assembly may correlate with the sun's location at a particular time of day. It may additionally be understood that while the first and second actuation assemblies may correlate generally with time of year and time of day, both actuation assemblies and axes of rotation may be used to direct the payload at any time of day or year. For example, although the first actuation assembly may generally correspond with seasonal location, the first actuation assembly may additionally rotate the payload about the first axis of rotation to track the object based on the time of day. That is, both actuation assemblies may be used to track the object's movement across the sky during the course of a day, for example.

In various embodiments, a tracking device of the present disclosure may be mounted to or generally located on a ground surface, a platform surface, or a tower surface or other structure, such as a cell phone or other communication tower or a solar power tower. For example, where the tracking device is mounted on a cell phone or other communication tower, the tracking device may track the location of a satellite and/or may direct its payload toward the satellite. In other embodiments, the tracking device may be located on a solar power tower, where the device may track the location of the sun and/or may direct its payload, such as mirror or other reflective surface, at an angle relative to the sun such that sunlight may be reflected toward a power collector or other device on the power tower. In such tower embodiments, the tracking device may be controlled or directed automatically and/or remotely, in some embodiments.

In some embodiments, the tracking device may operate, at least in part, over a wired or wireless network. A wireless connection may be, for example, an internet, Wi-Fi, Bluetooth, or other wireless connection. In some embodiments, the device may have a digital radio such as a Zigbee radio, which may allow the tracking device to communicate with one or more additional tracking devices or other communication devices over a wireless network. In this way, one or more tracking devices may be configured to share information, such as GPS information, tracking and positioning information, power consumption information, efficiency information, and/or other information over a wireless network. In some embodiments, the network and communication link may be maintained during power shut offs.

In some embodiments, the tracking device may receive an instruction to turn away from the object being tracked across the sky or otherwise away from its point of direction. For example, where the tracking device is tracking the sun to collect solar light or radiation, if the tracking device reaches some input or output limit or it is otherwise determined that solar light or radiation need not be collected for a period of time, the tracking device may be configured to receive an instruction to direct the payload away from the sun. Such an instruction may be received locally or remotely over a wired or wireless connection. For example, the instruction may be received from a device having a Zigbee radio. In some embodiments, the instruction may be received automatically when a sensor, for example, determines that the tracking device should stop collecting solar light or radiation. In other embodiments, the instruction may be input into the tracking device manually or may be received based on some user input.

In some embodiments, one tracking device may operate as a node to control one or more additional tracking devices. For example, one tracking device may aggregate the information received from multiple tracking devices. The single tracking device may direct and control positioning of the additional tracking devices, in some embodiments.

In some embodiments, a software application may allow a computing device to communicate with one or more tracking devices. A computing device may be a desktop or laptop computer, tablet, or mobile phone, for example. The software application may be used to communicate with one or more tracking devices over a wired or wireless network. The software application, such as a mobile device application for example, may allow a user to calibrate the tracking device locally or remotely. The application may further allow a user to collect data and/or provide user inputs locally or remotely.

In the foregoing description, a tracking device has been described. The tracking device is configured to track an object in space, such as the sun, as the object moves across the sky. The tracking device is further configured to direct a payload toward the object in space or toward an angle relative to the object in space. The tracking device may continuously or intermittently determine the location of the moving object, and adjust the position of the payload accordingly. The tracking device may calculate the position of the moving object based on GPS information, such as triangulated coordinates of the tracking device, date, and time. Generally, the tracking device may be capable of tracking an object such as the sun from anywhere on the earth's surface. The tracking device employs one or more actuation assemblies to position the payload toward or relative to the moving object. The one or more actuation assemblies operate through linear motion. Moreover, the tracking device may operate with relatively low power consumption. The tracking device may communicate with one or more additional tracking devices or other communication devices over a wired or wireless network.

For purposes of this disclosure, any system described herein may include any instrumentality or aggregate of instrumentalities operable to compute, calculate, determine, classify, process, transmit, receive, retrieve, originate, switch, store, display, communicate, manifest, detect, record, reproduce, handle, or utilize any form of information, intelligence, or data for business, scientific, control, or other purposes. For example, a system or any portion thereof may be a personal computer (e.g., desktop or laptop), tablet computer, mobile device (e.g., personal digital assistant (PDA) or smart phone), server (e.g., blade server or rack server), a network storage device, or any other suitable device or combination of devices and may vary in size, shape, performance, functionality, and price. A system may include random access memory (RAM), one or more processing resources such as a central processing unit (CPU) or hardware or software control logic, ROM, and/or other types of nonvolatile memory. Additional components of a system may include one or more disk drives or one or more mass storage devices, one or more network ports for communicating with external devices as well as various input and output (I/O) devices, such as a keyboard, a mouse, touchscreen and/or a video display. Mass storage devices may include, but are not limited to, a hard disk drive, floppy disk drive, CD-ROM drive, smart drive, flash drive, or other types of non-volatile data storage, a plurality of storage devices, or any combination of storage devices. A system may include what is referred to as a user interface, which may generally include a display, mouse or other cursor control device, keyboard, button, touchpad, touch screen, microphone, camera, video recorder, speaker, LED, light, joystick, switch, buzzer, bell, and/or other user input/output device for communicating with one or more users or for entering information into the system. Output devices may include any type of device for presenting information to a user, including but not limited to, a computer monitor, flat-screen display, or other visual display, a printer, and/or speakers or any other device for providing information in audio form, such as a telephone, mobile phone, a plurality of output devices, or any combination of output devices. A system may also include one or more buses operable to transmit communications between the various hardware components. A device or system of the present disclosure may include or operate using a field programmable gate array or other hardware having reconfigurable electrical circuitry such as one or more programmable logic blocks.

One or more programs or applications, such as a web browser, and/or other applications may be stored in one or more of the system data storage devices. Programs or applications may be loaded in part or in whole into a main memory or processor during execution by the processor. One or more processors may execute applications or programs to run systems or methods of the present disclosure, or portions thereof, stored as executable programs or program code in the memory, or received from the Internet or other network. Any commercial or freeware web browser or other application capable of retrieving content from a network and displaying pages or screens may be used. In some embodiments, a customized application may be used to access, display, and update information. In some embodiments, a software application may be used to update or upgrade operational code, programming, and/or firmware of systems or devices of the present disclosure. Such a software application may be a mobile phone application, a computer application, and/or may be accessible remotely via a wired or wireless data link.

Hardware and software components of the present disclosure, as discussed herein, may be integral portions of a single computer or server or may be connected parts of a computer network. The hardware and software components may be located within a single location or, in other embodiments, portions of the hardware and software components may be divided among a plurality of locations and connected directly or through a global computer information network, such as the Internet.

necessary tasks defined by a computer-executable program code. Computer-executable program code for carrying out operations of the present disclosure may be written in an object oriented, scripted or unscripted programming language such as Java, Perl, PHP, Visual Basic, Smalltalk, C++, C#, VHDL, Verilog, or the like. However, the computer program code for carrying out operations of the present disclosure may also be written in conventional procedural programming languages, such as the C, programming language, assembly language, or similar programming languages. A code segment may represent a procedure, a function, a subprogram, a program, a routine, a subroutine, a module, an object, a software package, a class, or any combination of instructions, data structures, or program statements. A code segment may be coupled to another code segment or a hardware circuit by passing and/or receiving information, data, arguments, parameters, or memory contents. Information, arguments, parameters, data, etc. may be passed, forwarded, or transmitted via any suitable means including memory sharing, message passing, token passing, network transmission, etc..

In the context of this document, a computer readable medium may be any medium that can contain, store, communicate, or transport the program for use by or in connection with the systems disclosed herein. The computer-executable program code may be transmitted using any appropriate medium, including but not limited to the Internet, optical fiber cable, radio frequency (RF) signals or other wireless signals, or other mediums. The computer readable medium may be, for example but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device. More specific examples of suitable computer readable medium include, but are not limited to, an electrical connection having one or more wires or a tangible storage medium such as a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), a compact disc read-only memory (CD-ROM), or other optical or magnetic storage device. Computer-readable media includes, but is not to be confused with, computer-readable storage medium, which is intended to cover all physical, non-transitory, or similar embodiments of computer-readable media.

Various examples of the present disclosure may be described herein with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products. It is understood that each block of the flowchart illustrations and/or block diagrams, and/or combinations of blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer-executable program code portions. These computer-executable program code portions may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a particular machine, such that the code portions, which execute via the processor of the computer or other programmable data processing apparatus, create mechanisms for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks. Alternatively, computer program implemented steps or acts may be combined with operator or human implemented steps or acts.

Additionally, although a flowchart may illustrate a method as a sequential process, many of the operations in the flowcharts illustrated herein can be performed in parallel or concurrently. In addition, the order of the method steps illustrated in a flowchart may be rearranged. Similarly, a method illustrated in a flow chart could have additional steps not included therein or fewer steps than those shown. A method step may correspond to a method, a function, a procedure, a subroutine, a subprogram, etc..

Claim 1:
A tracking device (<NUM>) for tracking the location of a moving object, comprising:
a spine portion (<NUM>) for carrying a payload (<NUM>);
an upright portion (<NUM>) supporting the spine portion (<NUM>);
an arm portion (<NUM>) between the upright portion (<NUM>) and the spine portion (<NUM>), wherein the arm portion (<NUM>) comprises a lateral member (<NUM>) and one or more connector arms (<NUM>), wherein the arm portion (<NUM>) is coupled to the upright portion (<NUM>) by a single axis support (<NUM>) comprising a pivoted connection and
wherein the spine portion (<NUM>) is supported by each connector arm (<NUM>) a connector (<NUM>) that allows the spine portion (<NUM>) to rotate, the spine portion (<NUM>) defining a second axis of rotation (<NUM>), wherein the second axis of rotation (<NUM>) aligns with a longitudinal axis of the spine portion (<NUM>), and wherein a first axis of rotation (<NUM>) is orthogonal to the second axis of rotation (<NUM>);
a first linear actuation assembly (<NUM>) causing the payload (<NUM>) to rotate about the first axis of rotation (<NUM>);
a second linear actuation assembly (<NUM>) causing the payload (<NUM>) to rotate about the second axis of rotation (<NUM>); and
a control module comprising a Global Positioning System and configured to determine a position of a moving object in the sky based on a position of the tracking device on a surface of the Earth, the local time of day and date, the control module further configured to operate the first and second linear actuation assemblies (<NUM>, <NUM>) to direct the payload (<NUM>) relative to the moving object.