HK1180387A - Heliostat repositioning system and method - Google Patents

Abstract

A system and method for providing real time control of a heliostat array or CPV/PV module that reduces actuation cost, the disclosure reduces the fixed cost of calibrating and repositioning an individual surface. This simultaneously removes the core engineering assumption that drives the development of large trackers, and enables a system and method to cost effectively track a small surface. In addition to lower initial capital cost, a small heliostat or solar tracker can be pre-assembled, mass-produced, and shipped more easily. Smaller mechanisms can also be installed with simple hand tools and do not require installers to rent expensive cranes or installation equipment.

Description

Heliostat repositioning system and method

RELATED APPLICATIONS

This application claims priority to U.S. provisional application No.61/349697 filed on 28/5/2010, U.S. provisional application No.61/364729 filed on 15/7/2010, and U.S. provisional application No.61/419685 filed on 3/12/2010, all of which are incorporated herein by reference in their entirety.

Technical Field

The present invention relates to solar tracking and calibration devices, and in particular to a concentrating photovoltaic tracking system that requires constant repositioning to maintain alignment with the sun.

Background

In an attempt to reduce the price of solar energy, there has been much development in reducing the cost of precisely repositioning and calibrating surfaces in two degrees of freedom. In concentrated solar thermal systems, heliostat arrays utilize a two-axis repositioning mechanism to redirect sunlight to a central tower by making the normal vector of the heliostat bisect the angle between the current sun position and the target. The heat generated by the central tower can then be used to generate steam for industrial applications or electricity for utility grids.

Concentrating Photovoltaic (CPV) systems use a two-axis mechanism to obtain the position where the vector normal to the CPV surface coincides with the solar position vector. When the CPV surface is aligned to the sun, the internal optics are able to concentrate sunlight to a small high efficiency photovoltaic cell.

The dual axis positioning system also enables flat panel Photovoltaic (PV) systems to generate more power through solar tracking. Compared to fixed, inclined systems, dual-axis PV systems produce 35-40% more energy on an annual basis. While this increase in energy production appears attractive, current technology ignores the value of enabling dual-axis solar tracking by adding 40-50% to the total system capital and maintenance costs.

Conventional solutions to the problem of controlling and calibrating individual surfaces fall into one of three main strategies: active individual actuation, modular or mirror linkage, and passive control. In active individual actuation mode, each two-axis system requires two motors, a microprocessor, and a rearWith power supplies, field wiring, and an electronic system to control and calibrate each surface. Furthermore, all components must carry over a 20 year life and the system requires sealing against the harsh installation environment. In an attempt to amortize the fixed cost of controlling an individual surface, the traditional engineer's view in the individual actuation paradigm is to establish 150 square meters (m)²) And a 225 square meter PV/CPV tracker. While control costs are reduced at this size, large trackers have increased requirements for steel, mounts, and installation.

Another approach attempts to solve the fixed control cost problem by ganging together multiple surfaces with cables or mechanical links. While this effectively amortizes motor actuation costs, its requirement for ground flatness is severe, greatly complicates the installation process, and entails significant steel costs due to the required stiffness of the mechanical linkage. Heliostats and CPV systems require separate adjustments that add to system complexity and maintenance costs due to common ground subsidence and imperfections in manufacturing and installation.

Passive systems that track the sun using hydraulic fluid, bimetallic strips, or biomimetic materials are limited to flat panel photovoltaic applications and do not perform well when compared to individually actuated or ganged systems. Furthermore, these systems cannot perform a back tracking algorithm that optimizes the solar field for energy production and ground coverage ratio.

Disclosure of Invention

It is a general object of some embodiments to provide a low cost solar tracking system that can accurately control and calibrate a surface in two degrees of freedom without a separate microprocessor, azimuth drive, elevation drive, central control system, or backup power supply. These components are replaced by a single robotic controller with adjustably oriented mechanical position locking mechanisms and autonomously adjusting a long row (100+) of individual mirrors, CPV modules or flat panel solar panels.

A second general object of some embodiments is to eliminate the need for a separate solar calibration sensor by coupling a calibration sensor system with a robotic controller so that the device can determine the precise orientation of the mirror, CPV module or solar panel and adjust it according to the field layout, known target and/or current sun position.

A third general object of some embodiments is to lock the position of the mechanical position lock mechanism when the robotic controller is not repositioning the mechanical position lock mechanism. At its least complex level, the mechanical position locking mechanism comprises a single deformable coupling or a joint with high friction.

A fourth general object of some embodiments is to utilize a gear or gear train system in a mechanical position locking mechanism to translate rotational repositioning of two input shafts into two degrees of freedom of a surface. The orientation of the surface can be locked by using an external braking system or by designing the gear or gear train system such that it cannot be back driven.

A fifth general object of some embodiments is to adjust a separate mechanical position locking mechanism using a magnetic or electromagnetic interface that eliminates the need for the robot controller to directly contact the mechanical interface supporting a precisely controlled surface.

A sixth general object of some embodiments is to significantly reduce installation costs and complexity by pre-assembling multiple rows of position locking mechanisms, and by using a pole base to eliminate the need for flat installation sites.

A seventh general object of some embodiments is to provide power to a robot controller using an on-board energy storage system in conjunction with a charging mechanism.

An eighth general object of some embodiments is to provide power to a robot controller using a live rail or tethered wire system that eliminates the need for on-board energy storage.

A ninth general object of some embodiments is to utilize the heliostat repositioning system in conjunction with a central receiver for solar thermal power, a central photovoltaic receiver, a central receiver for water desalination and industrial steam applications, or to cost-effectively track CPV modules or PV panels.

A system for controlling a plurality of solar surfaces, comprising: a support beam or rail; a first solar surface of the plurality of solar surfaces coupled to a first end of a first support structure, wherein a second end of the first support structure is coupled to a first location of a track beam and the first support structure comprises a first position locking mechanism; a second solar surface of the plurality of solar surfaces coupled to the first end of the second support structure, wherein the second end of the second support structure is coupled to a second location of the track and the second support structure comprises a second location locking mechanism; and a robotic controller including a drive system for positioning the robotic controller on a track, the drive system modifying an orientation of a first solar surface when the robotic controller is positioned near the first location of the track and modifying an orientation of a second solar surface when the robotic controller is positioned near the second location of the track.

These general objects of the invention as set forth are not exclusive and are not intended to limit the scope of the invention.

The features and advantages described in this specification are not all-inclusive and, in particular, many additional features and advantages will be apparent to one of ordinary skill in the art in view of the drawings and specification. Moreover, it should be noted that the language used in the specification has been principally selected for readability and instructional purposes, and may not have been selected to delineate or circumscribe the inventive subject matter.

Drawings

FIG. 1 is an illustration of an environment in which an embodiment of the invention can operate.

FIG. 2 is an illustration of a Photovoltaic (PV) surface having a mechanical position locking mechanism according to an embodiment.

FIG. 3 is a more detailed illustration of a mechanical position locking mechanism according to an embodiment.

FIG. 4 is an illustration of an exploded view of a mechanical position locking mechanism according to an embodiment.

FIG. 5 is an illustration of a mechanical position locking system attached to a support beam according to an embodiment.

FIG. 6 is a diagrammatic view of a support beam ground mounting system according to an embodiment.

FIG. 7 is a diagram of a two-stage gear train system interfacing with a mechanical position locking mechanism according to an embodiment.

FIG. 8 is a diagrammatic view of another embodiment of a two-stage gear train system interfacing with a mechanical position locking mechanism.

FIG. 9 is a diagram of another embodiment of a two-stage gear train system utilizing an actuated braking mechanism.

FIG. 10 is an illustration of an electromagnetic interface, according to an embodiment.

Fig. 11 is an illustration of a system that provides power to a robot controller via a contact-based charging system, according to an embodiment.

FIG. 12 is a diagram of a system that provides power to a robot controller via a powered rail according to an embodiment.

Fig. 13 is an illustration of a robot controller according to an embodiment.

Fig. 14 is a more detailed illustration of a robot controller with its top housing removed, according to an embodiment.

Fig. 15 is a more detailed illustration of an electromagnetic interface system of a robot controller according to an embodiment.

FIG. 16 is a diagram of a robot controller that calibrates and/or adjusts each position locking mechanism using a mechanical interface, according to an embodiment.

FIG. 17 is a diagram of a robot controller that calibrates and/or adjusts each position locking mechanism using two electromagnetic interfaces, according to an embodiment.

Fig. 18 is an illustration of a robot controller according to an embodiment.

FIG. 19 is a diagram of a robot controller utilizing a mechanical conditioning interface, according to an embodiment.

FIG. 20 is a diagram of a robot controller utilizing two electromagnetic conditioning interfaces, according to an embodiment.

The figures depict various embodiments of the present invention for purposes of illustration only. One skilled in the art will readily recognize from the following discussion that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles of the invention described herein.

Detailed Description

A preferred embodiment of the invention will now be described with reference to the figures, in which like reference numbers indicate identical or functionally similar elements.

Reference in the specification to "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the invention. The appearances of the phrase "in one embodiment" or "an embodiment" in various places in the specification are not necessarily all referring to the same embodiment.

Some portions of the detailed descriptions which follow are presented in terms of algorithms and symbolic representations of operations on data bits within a computer memory. These algorithmic descriptions and representations are the means used by those skilled in the data processing arts to most effectively convey the substance of their work to others skilled in the art. An algorithm is here, and generally, conceived to be a self-consistent sequence of steps (instructions) leading to a desired result. The steps are those requiring physical manipulations of physical quantities. Usually, though not necessarily, these quantities take the form of electrical, magnetic, or optical signals capable of being stored, transferred, combined, compared, and otherwise manipulated. It has proven convenient at times, principally for reasons of common usage, to refer to these signals as bits, values, elements, symbols, characters, terms, numbers, or the like. Furthermore, it is also sometimes convenient to refer to some arrangements of steps requiring physical manipulations or conversion of physical quantities or representation of physical quantities as modules or code devices, without loss of generality.

However, all of these and similar terms are to be associated with the appropriate physical quantities and are merely convenient labels applied to these quantities. Unless specifically stated otherwise as apparent from the following discussions, it is appreciated that throughout the specification discussions utilizing terms such as "processing" or "computing" or "calculating" or "calibrating" or "determining" or "displaying" or the like, refer to the action and processes of a computer system, or similar electronic computing device (such as a particular computing machine), that manipulates and transforms data represented as physical (electronic) quantities within the computer system memories or registers or other such information storage, transmission or display devices.

Certain aspects of the present invention include process steps and instructions in the form of an algorithm as described herein. It should be noted that the process steps and instructions of the present invention could be embodied in software, firmware or hardware, and when embodied in software, could be downloaded to reside on and be operated from different platforms used by a variety of operating systems. The present invention can also be located in a computer program product that is executable on a computer system.

The present invention also relates to apparatus for performing the operations herein. The apparatus may be specially constructed for the purposes of example, a particular computer, or it may comprise a general purpose computer selectively activated or reconfigured by a computer program stored in the computer. Such a computer program may be stored in a computer readable storage medium, such as, but is not limited to, any type of disk including floppy disks, optical disks, CD-ROMs, magnetic-optical disks, read-only memories (ROMs), Random Access Memories (RAMs), EPROMs, EEPROMs, magnetic or optical cards, Application Specific Integrated Circuits (ASICs), or any type of media suitable for storing electronic instructions, and each coupled to a computer system bus. The memory can include any of the above devices and/or other devices capable of storing information/data/programs. Further, the computers referred to in the specification may include a single processor or may be architectures employing multiple processor designs for increased computing capability.

The algorithms and displays presented herein are not inherently related to any particular computer or other apparatus. Various general-purpose systems may also be used with programs in accordance with the teachings herein, or it may prove convenient to construct more specialized apparatus to perform the method steps. The structure for a variety of these systems will appear from the description below. In addition, the present invention is not described with reference to any particular programming language. It will be appreciated that a variety of programming languages may be used to implement the teachings of the invention as described herein, and any references below to specific languages are provided for disclosure of enablement and best mode of the present invention.

Moreover, the language used in the specification has been principally selected for readability and instructional purposes, and may not have been selected to delineate or circumscribe the inventive subject matter. Accordingly, the disclosure of the present invention is intended to be illustrative, but not limiting, of the scope of the invention.

Depending on the wasted actuation costs incurred by real-time control of the heliostat array or CPV/PV module, embodiments of the invention seek to eliminate the fixed costs of calibrating and repositioning the individual surfaces. This also eliminates the need for core engineering to drive the development of large trackers and enables the present invention to cost effectively track small surfaces. In addition to lower initial capital costs, small heliostats or solar trackers can be more easily preassembled, mass produced, and shipped. Smaller mechanisms can also be installed with simple hand tools and do not require installers to rent expensive cranes or installation equipment.

Referring now to the drawings, FIGS. 1-6 show one configuration for a pre-assembled mechanical position locking mechanism row capable of maintaining the position of multiple separate surfaces with two degrees of freedom. These surfaces, such as solar surfaces, can be curved mirrors, flat mirrors, Photovoltaic (PV) modules that can include Concentrating Photovoltaic (CPV) modules, or flat panel solar panels. For ease of discussion, these surfaces will be referred to as PV surfaces.

FIG. 1 is an illustration of an environment in which an embodiment of the invention can operate. Fig. 1 depicts one possible configuration of a design in which the orientation of a separate surface 101 is adjustable relative to a rigid support beam 102 (also referred to herein as a "rail"). The support beam can be made of steel, aluminum, plastic, fiberglass, or a material that can provide sufficient rigidity to support a solar surface. The figure shows each surface attached to the beam via a mechanical position locking mechanism 103. In one embodiment, the independent robotic controller 104 moves along a rigid support beam and interfaces with a separate mechanical position locking mechanism to adjust the biaxial orientation of the different surfaces. The robotic controller paradigm weighs the fact that the solar position vector moves only 15 degrees per hour and thus can minimize its cost by adjusting multiple surfaces. Basically, a better robot-without reducing motor, controller, power supply or wiring costs-would enable a more attractive system economy, as the devices can be continuously upgraded to move faster between stations, adjust faster and carry a longer life span.

In an alternative embodiment, the only functional task of the rigid support beam (track) is to transport the robotic controller between solar surfaces. In this embodiment, each mechanical position locking mechanism has a separate base. The rigid support beam thus acts as a lightweight rail, which may be made of plastic (e.g., polyvinyl chloride (PVC) tubing), fiberglass aluminum, steel, or any material capable of supporting the weight of the robotic controller. The track may be disposed adjacent to a plurality of mechanical position locking mechanisms. The rails may also be flexible to allow for installation tolerances of the individual mounts used to support each mechanical position locking mechanism. For photovoltaic applications requiring a large amount of space between solar surfaces, the use of rigid support beams as non-structural members is preferred.

FIG. 2 is an illustration of a Photovoltaic (PV) surface having a mechanical position locking mechanism according to an embodiment. Fig. 2 shows surface 101 attached to mechanical position locking mechanism 103, and the mechanism is attached to beam 102. The figure also shows a plurality of calibration points 201 on the repositionable surface. The general purpose of these points is to enable the robot controller 104 to sense the orientation of the surface by determining the distance from its calibration sensor or sensors 202 to the plurality of calibration points. The robot controller may then use the onboard computer to fit these found positions of the points to the geometric plane. These calibration points can be virtual nodes generated by the robot controller or physical marks on the surface. Note also that these points are primarily for visual purposes and do not necessarily have physical calibration points. In one embodiment, the calibration system of the robot controller comprises a structured light emitting device and a collocated camera capable of detecting the structured light. The onboard image processing unit uses triangulation of the detected features to determine depth from the camera. A depth map is then formed which fits the detected features to the geometric plane. The kinematics of the aforementioned planes determine the relative orientation.

FIG. 3 is a more detailed illustration of a mechanical position locking mechanism according to an embodiment. FIG. 3 is a close-up view of the mechanical position locking mechanism. The mechanism may include a gear train that controls the orientation of the surface in two degrees of freedom. It comprises an inner coupling structure 301, an outer tubular coupling structure 302 enclosing the inner coupling, and right angle gearboxes 303A, 303B mounted to a shaft 304 fixed to the inner tubular coupling structure. In the most basic functional form of the system, a single gear is fixed to the internal coupling structure 305. Rotation of the gear directly adjusts the azimuthal orientation of surface 101.

An additional gear 306 is fixed to the outer tubular coupling. Rotation of this gear adjusts the position of the input gear 303A of the right angle gearbox. The shaft 304 of the output gear 303B in the right angle gear box is fixed to the internal coupling structure. The gears fixed to the inner link 305 can thereby control the azimuthal orientation of the surface, and the gears fixed to the outer link 306 can control the elevation or tilt of the repositionable surface. The right angle gearboxes 303A, 303B may utilize bevel gears, constant diameter bevel gears, face gears, magnetic gears, or a turbine system. Similarly, the gears 305, 306 fixed to the inner and outer couplings may be spur, constant diameter bevel, worm, face, harmonic, magnetic, or helical gear systems or gear trains. These gears may serve as interfaces for the robot controller, but are not necessary from a functional point of view. As an example, the robot controller may engage the inner and outer links 301, 302 and directly rotate them.

The high level of the gear train system is intended to convert the rotation of two input links with fixed axes of rotation into two axis control of the surface. This mechanism greatly reduces the complexity of the robot controller because the two input links remain in the same position during adjustment. The restriction that both input links must have a fixed axis of rotation can be removed in order to reduce the complexity of the mechanical position locking mechanism. In these systems, the robot controller needs to compensate for input links that do not remain in the same position during adjustment.

Taking the distributed actuation paradigm of the present invention to the extreme, the mechanical position locking mechanism may comprise a single joint, lockable or flexible, that is fixed to a repositionable surface. In this type of solution, the robot would need to be able to unlock the joint, adjust the surface using an on-board actuation system that can directly contact the surface, and lock the joint before moving to another mechanical position locking mechanism.

FIG. 4 is an illustration of an exploded view of a mechanical position locking mechanism according to an embodiment. Fig. 4 is an exploded view of fig. 3. The outer tubular coupling structure 302 and the two gears fixed thereto are shown as separate components. This view shows that input gear 303A in the right angle gearbox is fixed to outer coupling structure 302 and thereby rotates about inner coupling 301. The output gear 303B of the right angle gearbox is free to rotate about a shaft 304 fixed to the internal coupling structure. The particular configuration of the gears in the gear train of the mechanical position locking mechanism will allow the system to be back driven by torsional or uneven surface loading. This can be prevented by introducing a high degree of friction in the system or by selecting gear systems such as turbine or harmonic gear sets that cannot be back driven.

FIG. 5 is an illustration of a mechanical position locking system attached to a support beam according to an embodiment. Fig. 5 shows the mechanical position locking mechanism attached to the support beam 102. It also shows how one gear 305 can be attached to the inner coupling 301 and the other gear 306 can be attached to the outer coupling 302. In one embodiment, the internal coupling structure may have a flange 501 at its base. The flange will prevent twisting or other forces from pulling the mechanical position locking mechanism away from the support beam. The internal coupling structure may also interface with bearings 502 fixed to the support beam 102 in order to reduce friction.

FIG. 6 is a diagrammatic view of a support beam ground mounting system according to an embodiment. Fig. 6 shows how the beam 102 may be securely mounted in a ground mounting system. In one embodiment, the rod 601 may be driven into the ground and secured to the beam by mounting clips 602, which may or may not allow adjustment. Fig. 6 depicts the mounting clip as a standard U-bolt. These rods may also be placed in concrete or attached to weighted ballast that prevents twisting of the dumping system. In one embodiment, the ballast may be secured directly to the beam by mounting clips or standard bolt patterns. The driven bars provide the greatest degree of system flexibility as they can be mounted in a manner that changes depth to account for local variations in field height, although in some embodiments the beams 102 need not be leveled. The system may be configured with multiple support beams connected together to form one extended row for the robotic controller.

Fig. 7-9 show other possible configurations for the mechanical position locking mechanism. This configuration introduces additional gears to the gear train and a braking mechanism that maintains the position of the system when the robotic controller is not adjusting the surface. The brake mechanism is particularly useful for gear train systems that do not have inherent anti-backdrive capability.

FIG. 7 is a diagram of a two-stage gear train system interfacing with a mechanical position locking mechanism according to an embodiment. Fig. 7 illustrates one embodiment of a two-stage gear train system interfacing with the input gears 305, 306 of the mechanical position locking mechanism 103 shown in fig. 1-6. The purpose of the additional gear system is to make the control of the separate surface 101 more accurate and/or to provide direct gear train locking. In one embodiment, the robotic controller interfaces with one or more final stage components in the gear train system to minimize the amount of torque required to reposition the surface. In the gear train configuration depicted, the fixed link 704 supports a two-stage gear train system. The gear train includes a top final stage gear 701 that interfaces with a gear 306 fixed to the outer coupling and a bottom final stage gear 702 that interfaces with a gear 305 fixed to the inner coupling. These final gears may also interface with a brake mechanism. The brake mechanism is designed to lock the position of the gear, for example, when the robot controller is not adjusting a separate mechanical position locking mechanism, in order to prevent any significant or significant movement of the gear and thus any significant movement of the surface based on gear slippage, for example. One such braking mechanism incorporates a gear (such as a worm drive) that cannot be back driven into any stage of the gear train. This type of gear can passively lock the position of the individual surfaces without adding additional braking.

Other braking mechanisms can function by actively engaging and disengaging any gear in the gear train system, or directly with the inner and outer couplings. In the depicted mode, two springs force the top and bottom final stage gears 701, 702 into the gear locking mechanism 703 in order to prevent the gear train from back driving. In other configurations, the top and bottom final stage gears may have fixed vertical positions, and the gear locking mechanism may be spring-loaded. The gear locking mechanism may utilize friction pads and/or positive engagement 705 to prevent rotation of the final stage gear. To adjust the rotation of the final gear and reposition the surface, the robotic controller first needs to deactivate the braking mechanism.

The robot controller does not have to rotate both final gears in order to control the surface in both axes. For example, if the top final gear 701 in this configuration is locked and the bottom final gear 702 is rotated, the azimuthal orientation and tilt of the surface will be adjusted simultaneously. A robotic controller that takes advantage of this effect needs to be able to disengage the top final gear from its brake and rotate the bottom final gear to change only the azimuthal orientation of the surface.

FIG. 8 is a diagrammatic view of another embodiment of a two-stage gear train system interfacing with a mechanical position locking mechanism. Fig. 8 shows a simpler two-stage gear train system that takes advantage of this effect. A fixed coupling 704 may support the two-stage gear train system. In the depicted embodiment, the gear lock mechanism 703 only works in conjunction with the bottom final gear 702. The top final gear 701 shown in fig. 7 is replaced by an actuated brake mechanism 801. One end of the actuated post is equipped with a brake pad 802, which brake pad 802 can actively engage the external coupling structure 302 or engage a gear 306 fixed to the external coupling structure. The brake pads may utilize friction and/or positive engagement to prevent rotation of the engaged system. The other end 803 of the actuated cylinder may contain a metal or magnetic material to enable magnetic or electromagnetic adjustment. By actuating the system, the robot controller is able to effectively lock and unlock the external coupling structure. The brake actuator may be spring loaded in order to reduce the complexity of the robot controller.

FIG. 9 is a diagram of another embodiment of a two-stage gear train system utilizing an actuated braking mechanism. The two-stage gear train system utilizing the actuated brake mechanism 801 simultaneously locks the position of the gears fixed to the inner and outer linkages 305, 306. Similar to the actuated brake depicted in fig. 8, the brake mechanism may be spring loaded. The brake pad 802 may also be actuated by the screw drive system 901. To engage and disengage the brake mechanism, the robot controller must be able to rotationally control the input shaft 902 of the actuator. The input shaft may comprise a metal or magnetic material to enable magnetic or electromagnetic adjustment.

The robot controller interfaces with a mechanical position locking mechanism (depicted in fig. 1-9) to adjust the orientation of the repositionable surface. There are many such interfaces that can be used to accomplish this goal. One type of solution includes, but is not limited to, utilizing mechanical engagement to adjust the position of the input gear and/or the braking mechanism. This can be done using friction and/or positive engagement. Another type of solution includes, but is not limited to, using magnetic and/or electromagnetic engagement to adjust the position of the input gear and/or the braking mechanism. This type of solution has the potential to greatly increase the rated life of the robot controller, since it enables adjustment without physical contact. This type of engagement also seals the robotic controller and mechanical position locking mechanism from each other and the installation environment. Accurate station alignment is also less important for electromagnetic systems because magnetic couplings can inherently account for misalignment.

FIG. 10 is an illustration of an electromagnetic interface, according to an embodiment. FIG. 10 depicts one embodiment of a magnetic or electromagnetic interface. For ease of discussion, the term "electromagnetic" is used herein to include both electromagnetic and magnetic interfaces and effects. In this mode, the top final gear 701 and the bottom final gear 702 are equipped with a plurality of metal discs or magnets 1001. These disks interact with a magnetic or electromagnetic system on a robot controller (not shown). The magnetic or electromagnetic system of the robotic controller may provide normal forces on the top and bottom final gears. This effect is desirable because it can be utilized to disengage the final gear from its braking mechanism prior to and throughout the adjustment process. This may be accomplished by spring loading the final stage gear into the gear locking mechanism 702 that prevents rotation of the final stage gear as a default state. When the magnetic or electromagnetic system of the robotic controller is activated, it provides a normal force that disengages the top and bottom final stage gears from the gear locking mechanism. This in turn allows the robot controller to directly control the position of each final gear.

From a functional perspective, the final gear in the gear train system can behave as if it were half of an axial flux motor. The robotic controller may contain the other half of the axial flux motor envisioned and distribute this complexity-along with the complexity of individual calibration, wiring, and surface control-among many position locking mechanisms. However, the scope of the present invention is not meant to be limited to repositioning via rotational motion input. While these systems are envisioned as being easier to understand, the present invention may utilize a variety of input motions including linear or non-linear mechanisms to actuate the repositionable surfaces in two degrees of freedom.

Fig. 11 and 12 show various methods of providing power to a robot controller. The robot controller may require energy to power the electronic components and/or an on-board drive system capable of transporting the controller between conditioning stations. The robot controller may also require power to adjust the various position locking mechanisms.

Fig. 11 shows a system for providing power to a robot controller via a contact-based charging system, according to an embodiment. The purpose of the system is to charge an energy storage system onboard the robot controller. Charging system may include support arm 1101 that holds positive contact patch 1102 and negative contact patch 1103. The robot controller may engage these contact patches with metal brushes and/or wheels. The charging system may be arranged at any point along the beam. In a preferred embodiment, it is arranged at the end of a long row comprising a plurality of support beams 102 and position locking mechanisms 103. The robotic controller may use the charging system to recharge its energy storage system at any time. If it carries an on-board energy storage system with a small capacity, it can be recharged during or at the end of each row regulation cycle. In one embodiment, it will carry enough energy storage capacity for a full day to regulate and recharge during the night. The charger may utilize direct contact or electromagnetic induction to transfer power to the robot controller. The source of charging energy may be a battery that itself is charged using solar energy.

FIG. 12 is a diagram of a system that provides power to a robot controller via a powered rail according to an embodiment. Fig. 12 shows a system capable of providing continuous power to a robot controller via a live rail 1201. The system may be used to recharge an on-board energy storage system of the robotic controller or to power the robotic controller directly. The live rail may include a positive contact bar 1202 and a negative contact bar 1203, and the robot controller may engage the positive contact bar 1202 and the negative contact bar 1203 with brushes and/or wheels. The joint 1205 between the support beams requires an electrical path connector 1204 to form a continuous row of live tracks for the robot controller. The functional task of providing continuous power may also be accomplished by connecting wires from a power supply to the robot controller. In a tether system, the robot controller requires a mechanism such as a cable carrier to manage the excess wire.

Fig. 13-15 illustrate one embodiment of a robot controller that individually calibrates and/or adjusts each mechanical position locking mechanism. The purpose of a robotic controller is to aggregate the many complex control elements required to properly position the individual surfaces in one field-replaceable part. At its most basic functional level, the robot controller must be able to move between the mechanical position locking mechanisms, properly align itself to the adjustment station, disengage the braking mechanism (if needed), manipulate the mechanical position locking mechanism, and re-engage the braking mechanism (if needed). Additional calibration sensors may be attached to the robot controller to enable the robot to determine how the repositionable surface should be oriented for various solar applications. Fig. 13-15 show how the robot controller can adjust and calibrate the mechanical position locking mechanism in two degrees of freedom that transmits rotational input motion to a surface using a gear train system (see fig. 8).

Fig. 13 is an illustration of a robot controller according to an embodiment. Fig. 13 depicts an overview of a system that may be incorporated into the robot controller 104 to achieve the foregoing basic functional goals. These systems may include, but are not limited to: a drive system 1301 to transport the collection of systems between the mechanical position locking mechanisms; a power supply interface 1302 capable of receiving power from the live rail 1201, tethered cable, or static charging system; an energy storage system 1303 (see fig. 14) capable of receiving energy from the power source interface and providing power to the onboard systems; a central or distributed processing system 1304 (see FIG. 14) capable of giving and/or receiving instructions from the various components; a data recording system 1305 (see fig. 14) capable of storing information from the onboard sensors; a magnetic, electromagnetic or mechanical adjustment interface 1306 (see FIG. 14) capable of operating a mechanical position locking mechanism; a mechanical adjustment interface 1307 capable of engaging and/or disengaging the braking system; an internal wiring system to connect the system components; a rack 1308 to house system components; and a calibration system 1309 capable of characterizing the surface in two degrees of freedom. The calibration system includes a number of components, which may include but are not limited to: cameras, separate processing units, structured light emission and detection systems, laser distance sensors, and position location systems capable of determining the global or relative positioning of the robot controller.

In an alternative embodiment, multiple robot controllers may be included in a single track. This can increase the frequency of adjustment of the solar surface and also provide a failsafe system in the event that one or more of the robotic controllers cease to operate. The robot controller can include a computer (or other processing device, for example) that allows wireless or wired communication to other robot controllers and/or to a central station (not shown). The central station (or central stations) can include a processor, memory, storage, wireless communication means to provide a centralized system that can transmit and receive information to the robot controller and provide software/hardware updates and database updates. The centralized station can be local to the robot controller, for example within a few hundred meters. Additionally, the centralized station may communicate with a remote headquarters server that is able to maintain status and provide instructions to a number of remote solar energy collection systems.

Fig. 14 is a more detailed illustration of a robot controller with a top housing of the robot controller removed, according to an embodiment. Figure 14 shows the robot controller with the top housing removed. The depicted configuration uses two electromagnetic interfaces to adjust the mechanical position locking mechanism. An electromagnetic interface 1307 is used to adjust the position of the actuated brake mechanism 801. If the actuated brake mechanism is spring loaded and contains metal or magnetic material, the robot controller can engage and disengage the brakes by activating and deactivating simple electromagnets. If the actuated brake system utilizes a screw drive mechanism 901 for actuation, the electromagnetic interface of the robot controller provides a rotational action to the input shaft 902 of the actuator. This can be done by turning the interface towards the envisaged axial flux motor, where one end of the screw actuated braking mechanism comprises a metal or magnetic material and the interface 1307 of the robot controller comprises an electromagnet and control electronics.

Another electromagnetic interface 1306 is used to regulate the rotation of the final gear of the mechanical position lock mechanism. The interface may include a static or movable electromagnet that interacts with a metal or magnetic disk 1001 attached to the bottom final gear 702 of the mechanical position locking mechanism. The interface may behave as if it were an axial flux or induction motor, with complex components incorporated in the robot controller and a minimal number of passive components incorporated in the mechanical position locking mechanism.

A power supply connected to a powered rail (not shown) may transmit energy to the robot controller. The robot controller receives this power through a power interface 1302 which may include a wiper 1401 or wheels. The robot controller may store this electrical energy using its on-board energy storage system 1303.

A drive system 1301 onboard the robot controller can transport the collection of systems between the position lock mechanisms. This may be accomplished using a drive motor and drive wheel 1402. This object is also achieved by using an external drive mechanism such as a belt, chain or cable drive system.

Fig. 15 is a more detailed illustration of an electromagnetic interface system of a robot controller according to an embodiment. Figure 15 shows a close-up view of the electromagnetic interface system. One system 1307 is used to actuate the brake mechanism and the other active electromagnetic system 1306 is used to adjust the rotation of the bottom final gear of the position lock mechanism. The interface controlling the actuated braking mechanism may comprise a single electromagnet which interacts with the spring loaded braking mechanism via a magnetic engagement.

In this configuration, the active electromagnetic system includes four electromagnets 1501 on a rotating platform 1502. The platform is connected to a drive mechanism 1503 capable of providing sufficient torque to rotate the system. The four electromagnets are activated simultaneously and interact with the four metal or magnetic discs 1001 on the bottom final gear 702 of the mechanical position locking mechanism. As the drive system rotates the active electromagnetic system 1306, which in turn rotates the bottom final gear, which is now electromechanically coupled to the four electromagnets 1501. This enables the active electromagnetic system of the robot controller to adjust the positioning of the bottom final gear in the mechanical position locking mechanism.

FIG. 16 is a diagram of a robot controller that calibrates and/or adjusts each position locking mechanism using a mechanical interface, according to an embodiment. The mechanical adjustment interface physically engages a final gear of the mechanical position lock mechanism. This may be accomplished by positive engagement and/or friction. The depicted system utilizes two adjustment gears 1601 that cooperate with the final gear of the mechanical position locking mechanism. An on-board motor 1602 is attached to the adjustment gears 1601 and is able to rotate them precisely and individually. The onboard motor is thus able to control the position of the solar surface when the adjustment gear 1601 is engaged with the final gear of the mechanical position locking mechanism.

FIG. 17 is a diagram of a robot controller that calibrates and/or adjusts each position locking mechanism using two electromagnetic interfaces, according to an embodiment. Fig. 17 shows one embodiment of a robot controller that uses two static electromagnetic interfaces 1701 to calibrate and/or adjust each mechanical position locking mechanism. Each interface includes a plurality of electromagnetic coils 1702 that can be individually activated. These coils interface with metal or magnetic disks 1001 embedded in the final gears 701, 702 of the mechanical position locking mechanism. When properly started, the system can behave as if it were an axial flux or induction motor. These solenoids may be powered by the on-board energy storage system and/or power interface of the robot controller.

Fig. 18 is an illustration of a robot controller according to an embodiment. Fig. 18 combines the systems described in fig. 13-15 and fig. 8 to better illustrate how a robotic controller may be used to calibrate and/or adjust a plurality of mechanical position locking mechanisms. The process may start with the start-up of the central processing unit of the robot controller. The computing system determines at a high level how the robot controller should interact with the system of mechanical position locking mechanisms. It is also capable of sending low level instructions to the on-board components to perform the aforementioned high level functions. In one embodiment, a step in the calculation process is to extract information from the past operating history and/or on-board calibration sensors 1309. This helps the robot controller to determine its current position on the support beam. The next step is to determine how the robot should transport itself to the next conditioning station. Once the calculations are made, the robot controller may start its drive system (which may include, for example, a single drive motor attached to the drive wheel) until it reaches the conditioning station. To identify the station, the robot controller may use any of a variety of methods for identifying the appropriate location. Examples include camera systems capable of detecting features of mechanical position locking mechanisms. Its drive system may also utilize prior knowledge of the system to move the robot controller a pre-calculated distance. The robotic controller may also use a metal or magnetic material detection system capable of sensing a piece of metal or magnet disposed at each mechanical position locking mechanism. Once at the position locking mechanism, the central processor may again send instructions to the drive system to achieve accurate station alignment.

Before the adjustment process begins, the robot controller may extract additional information from its past operational history and/or calibration sensors to better determine the current orientation of the repositionable surface and/or to calculate the required amount of adjustment. Once this is done, the robot controller may activate its electromagnetic interface 1307 that controls the position of the actuated brake mechanism 801. This effectively unlocks the position of gear 306, which is fixed to the external coupling structure.

The electromagnet 1501 in the active electromagnetic system 1306 can now be activated. This activation provides a normal force on the bottom final gear 702 of the mechanical position locking mechanism to release it from the gear locking mechanism 703. Once disengaged, the system is unlocked and can be repositioned by activating the drive mechanism 1503 which controls the rotational position of the active electromagnetic system. Rotation of the bottom final gear to adjust disengagement of the brake adjusts only the azimuthal orientation of the surface. To change the inclination of the surface, the robot controller can reengage the braking mechanism by deactivating its electromagnetic braking interface 1307. Adjusting the lower final gear of the engaged brake will adjust the pitch and azimuth orientation.

After the relocation process is completed, the central processing unit may record adjustment data for use during future relocations. It may also extract data from its calibration sensor to verify that the surface has been correctly repositioned. The validation process may use any of a variety of methods. Examples include the use of onboard light emitting mechanisms that project structured light onto the underside of the solar surface and side-by-side cameras that are capable of detecting the pattern of structured light on the solar surface. The onboard processing unit of the robot controller may then process this information to fit the plurality of detected points to the geometric plane. To verify that the surface is correctly positioned, the software of the robot controller checks that the desired orientation of the surface matches the measured orientation.

FIG. 19 is a diagram of a robot controller utilizing a mechanical conditioning interface, according to an embodiment. Fig. 19 combines the systems described in fig. 16 and 3 to better illustrate how a robotic controller may be used to calibrate and/or adjust multiple position locking mechanisms using a mechanical adjustment interface. The process of the robot controller is very similar to the process depicted in fig. 18. However, instead of actuating the electromagnetic interface to adjust the position of the position locking mechanism, this configuration uses a direct mechanical engagement.

After the robot controller itself has been properly aligned to the adjustment station and has calculated the adjustments needed to reposition the surface, it may have its adjustment gear 1601 physically engage the input gears 305, 306 of the mechanical position locking mechanism. The engagement process can be as simple as pulling accurately into the adjustment station and allowing the gear sets to mate. This simple engagement process demonstrates one of the major advantages of selecting a gear train system with an input shaft that remains in the same position throughout all travel points. Once engaged, the robotic controller may activate its on-board motor 1602 to rotate the input shaft of the mechanical position locking mechanism.

FIG. 20 is a diagram of a robot controller utilizing two electromagnetic conditioning interfaces, according to an embodiment. Fig. 20 combines the systems described in fig. 17 and 7 to better illustrate how a robotic controller may be used to calibrate and/or adjust multiple mechanical position locking mechanisms using two electromagnetic adjustment interfaces 1701. The process of the robot controller is very similar to the process depicted in fig. 18. However, instead of using an electromagnetic system to control the actuated braking mechanism, this configuration uses two static electromagnetic systems that can disengage the top and bottom final stage gears 701, 702 from the gear locking mechanism 703. These static electromagnetic systems are also capable of adjusting the rotation of the top and bottom final gears to effectively reposition the mechanical position locking mechanism.

After the robot controller itself has been properly aligned to the adjustment station and has calculated the required adjustment of the repositioning surface, it may start two static electromagnetic interfaces. This activation causes a normal force on the top final gear 701 and the bottom final gear 702 releasing them from the gear locking mechanism 703. Once the gear lock has been disengaged, the coils 1702 contained in each static electromagnetic interface may be individually activated to rotate the top and bottom final stage gears. After the final gear has been properly repositioned, the robot controller may deactivate its static electromagnetic system. This removes the normal force on the gear and allows the spring loaded system to return the gear to the locked position.

The robot controller adjustment process is simpler in a gear train system with inherent anti-backdrive capability. These systems do not require the robot controller to operate the brake mechanism during adjustment.

Although specific embodiments and applications have been illustrated and described herein, it is to be understood that the invention is not limited to the precise construction and components disclosed herein and that various modifications, changes, and variations may be made in the arrangement, operation, and details of the method and apparatus of the present invention without departing from the spirit and scope of the invention as set forth in the appended claims.

Claims (25)

1. A system for controlling a plurality of solar surfaces, comprising:

a rail for supporting the controller;

a first solar surface of the plurality of solar surfaces coupled to a first end of a first support structure, wherein a second end of the first support structure is adjacent a first location of the track and the first support structure comprises a first position locking mechanism;

a second solar surface of the plurality of solar surfaces coupled to the first end of the second support structure, wherein the second end of the second support structure is adjacent to a second location of the track and the second support structure comprises a second location locking mechanism; and

a robotic controller comprising a drive system for positioning the robotic controller on the track and correcting an orientation of the first solar surface when the robotic controller is positioned near the first position of the track, and correcting an orientation of the second solar surface when the robotic controller is positioned near the second position of the track.

2. The system of claim 1, wherein the first solar surface is less than 4 square meters in size and the second solar surface is less than 4 square meters in size.

3. The system of claim 1, wherein the robot controller further comprises:

a position sensing device to identify when the robotic controller is positioned near the first or second position;

an alignment module configured to interact with the first position locking mechanism when near the first position and configured to interact with the second position locking mechanism when near the second position.

4. The system of claim 3, wherein the first position locking mechanism comprises:

a first internal coupling structure for moving the first solar surface in response to interaction with the alignment module;

a first external coupling structure positioned about a portion of the first internal coupling structure for moving the first solar surface in response to interaction with the alignment module.

5. The system of claim 4, wherein the first and second sensors are arranged in a single package,

wherein the first internal coupling structure adjusts an azimuthal orientation of the first solar surface; and is

Wherein the first external coupling structure adjusts a rising orientation of the first solar surface.

6. The system of claim 5, wherein the first internal coupling structure includes a first internal coupling gear that interacts with the alignment module.

7. The system of claim 6, wherein the first external coupling structure includes a first external coupling gear that interacts with the alignment module.

8. The system of claim 3, wherein the alignment module interacts with the first position locking mechanism using a mechanical interface.

9. The system of claim 8, wherein the alignment module includes an alignment gear coupled to a gear in the first position locking mechanism to modify an orientation of the first solar surface when the robotic controller is positioned near the first position.

10. The system of claim 9, wherein the alignment module includes an alignment gear coupled to a gear in the second position locking mechanism to modify the orientation of the second solar surface when the robotic controller is positioned near the second position.

11. The system of claim 3, wherein the alignment module interacts with the first position locking mechanism using an electromagnetic interface.

12. The system of claim 11, wherein the first position locking mechanism comprises at least one first electromagnetic device, and wherein the alignment module comprises at least one second electromagnetic device, wherein the electromagnetic interface comprises the first electromagnetic device and the second electromagnetic device.

13. The system of claim 12, wherein the second electromagnetic device causes the first electromagnetic device to move and modify the orientation of the first solar surface.

14. The system of claim 1, wherein the first position locking mechanism prevents any significant movement of the first support structure when in a locked position.

15. The system of claim 1, further comprising:

a ground fixture coupled to the track to fixedly position the track.

16. The system of claim 15, wherein the track is not horizontal.

17. The system of claim 15, wherein the track is substantially horizontal.

18. The system of claim 1, wherein the robotic controller is positioned within the track.

19. The system of claim 1, wherein the track comprises a cover, the cover and track forming a closed path and the robotic controller traveling along the closed path.

20. The system of claim 1, wherein the robot controller comprises:

a calibration sensor to detect a first orientation of the first solar surface when positioned near the first location and to detect a second orientation of the second solar surface when positioned near the second location.

21. The system of claim 20, wherein the robot controller comprises:

a charging mechanism for charging the internal power storage device.

22. The system of claim 20, wherein the robot controller comprises:

a power input device connected to an external power source.

23. The system of claim 22, wherein the track is electrically charged and is the external power source.

24. The system of claim 1, wherein the track comprises a plastic pipe.

25. The system of claim 1, further comprising a second robot controller, wherein the first and second robot controllers communicate with each other using a wireless communication system.