Flexible robot for cleaning solar panels

Abstract

A system and method for cleaning solar panels using a. robot including one or more degrees of freedom configured to withstand deviations in solar panel field geometry.

Description

[0001] FLEXIBLE ROBOT FOR CLEANING SOLAR PANELS

[0002] RELATED APPLICATIONS

[0003] This application claims the benefit of priority under 35 USC §119(e) of U.S. Provisional Patent Application No. 63 / 700,697 filed on September 29, 2024, the contents of which are incorporated herein by reference in their entirety.

[0004] FIELD AND BACKGROUND OF THE INVENTION

[0005] The present invention, in some embodiments thereof, relates to a system and method for cleaning solar panels and, more particularly, but not exclusively, to a robot for cleaning solar panels configured to withstand deviations in field geometry.

[0006] BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Some embodiments of the invention are herein described, by way of example only, with reference to the accompanying drawings. With specific reference now to the drawings in detail, it is stressed that the particulars shown are by way of example and for purposes of illustrative discussion of embodiments of the invention. In this regard, the description taken with the dra wings makes apparent to those skilled m the art how embodim ents of the invention may be practiced.

[0008] In the drawings

[0009] Fig. 1 : Schematic diagram illustrating a solar panel and robot cleaner, in accordance with some embodiments of the current invention.

[0010] Figs. 2A-2D: Schematic diagrams illustrating a rigid robot (Figs. 2A and 2C) and an articulated robot (Figs. 2B and 2D) in alignment (Figs. 2A and 2B) with a panel and out of alignment with the panel (Figs. 2C and 2D), in accordance with some embodiments of the current invention.

[0011] Figs. 3A-D: Schematic diagrams illustrating a connection between a brush unit and a cart, in accordance with some embodiments of the current invention. Figs. 4A-4B are schematic diagrams illustrating exemplary cleaning robots with multiple brush modules and rigid middle wheels, in accordance with some embodiments.

[0012] Figs. 4C-4J are schematic diagrams illustrating exemplary cleaning robots with multiple brush modules and an articulated middle wheel, in accordance with some embodiments.

[0013] Figs. 5A-B: A block diagrams illustrating exemplary robot cleaning systems, in accordance with some embodiment of the current invention.

[0014] Fig. 6: A flow chart illustrating a method for use of a robot cleaning system, in accordance with some embodiment of the current invention.

[0015] Figs. 7A-C: Schematic diagrams illustrating a robot with a degree of rotational rotation, in accordance with some embodiments of the current invention.

[0016] Figs. 8A-C: Schematic diagrams illustrating a side wheel system for use with a cleaning robot, in accordance with some embodiments of the current invention.

[0017] Figs. 9A-D are schematic diagrams illustrating a robot cleaning system, in accordance with some embodiments of the current invention.

[0018] Fig. 10: A block diagram illustrating an exemplary side wheel system, in accordance with an embodiment of the current invention of the current invention.

[0019] Fig. 11: A block diagram illustrating an exemplary robot cleaning system, in accordance with an embodiment of the current invention of the current invention.

[0020] Fig. 12: A flow chart illustrating a method of use of an exemplary system, in accordance with an embodiment of the current invention of the current invention.

[0021] SUMMARY OF THE INVENTION

[0022] A system of one or more computers can be configured to perform particular operations or actions by virtue of having software, firmware, hardware, or a combination of them installed on the system that in operation causes or cause the system to perform the actions. One or more computer programs can be configured to perform particular operations or actions by virtue of including instructions that, when executed by data processing apparatus, cause the apparatus to perform the actions. In one general aspect, system may include a cleaning unit. System may also include running gear maintaining said cleaning unit over a face of the panel. System may furthermore include an articulated joint connecting between the cleaning unit and the running gear. Other embodiments of this aspect include corresponding computer systems, apparatus, and computer programs recorded on one or more computer storage devices, each configured to perform the actions of the methods.

[0023] Implementations may include one or more of the following features. System where said panel includes a solar panel. System where said articulated joint allows rotation of the running gear with respect to the cleaning unit within a plane of the face of the panel. System where said articulated joint is a revolute joint. System where the running gear includes a support wheel resting on said face of said panel. System where said support wheel is a drive wheel of the system. System where said support wheel is a neutral wheel. System where said articulated joint includes a swivel caster. System where the swivel caster has a limited range of rotation. System where the running gear includes a side support configured to run along an edge of the panel for limiting longitudinal movement of the cleaning unit along the face of the panel. System side support includes two side wheels mounted on opposite sides of a rocker beam and where said articulated joint attaches between said rocker beam and said cleaning unit. System where the running gear includes a top carriage and the side wheels are positioned to roll laterally along a top edge of the panel. System where the side support is configured to support at least partially a component of weight of the cleaning unit parallel to the face of the panel. System further including a top carriage and where said top carriage includes said side support and a normal support panel supporting at least partially a component of a weight of the cleaning assembly perpendicular to the face of the panel. System where the normal support includes at least one of a wheel and a continuous track resting on said face of said panel. Implementations of the described techniques may include hardware, a method or process, or a computer tangible medium.

[0024] In one general aspect, system may include a cleaning robot configured clean a panel, where the robot includes an upper driving cart powered by a water motor. System may furthermore include a lower secondary cart attached to the lower edge of the panel. System may in addition include a brush unit connected to the driving cart and the secondary cart via a brush shaft. System may moreover include at least two side wheels with a rotational axis, where the side wheels are attached to the drive cart and are configured to maintain the robot in a position relative to panel, and where the rotational axis is configured to facilitate the robot climbing a step or obstacle without deviating its path. Other embodiments of this aspect include corresponding computer systems, apparatus, and computer programs recorded on one or more computer storage devices, each configured to perform the actions of the methods.

[0025] Implementations may include one or more of the following features. System where the side wheels are mounted to a side wheel arm. System where the side wheel arm includes the rotational axis. System where the rotational axis is connected to the driving cart by a bracket. System where the brush unit is rigid. System where the brush unit includes one or more brush modules and one or more middle carts. System where middle cart is a driven middle cart or a non-driven middle cart. System where the non-driven middle cart includes one or more neutral wheels with a steering rotation axis and a directional stability system. System where the brush unit is connected to the driving cart and the secondary cart by an axial connection. System where the secondary cart includes spring loaded side wheels. Implementations of the described techniques may include hardware, a method or process, or a computer tangible medium.

[0026] In one general aspect, the method may include retaining a cleaning machine over a panel with running gear. The method may also include moving a cleaning machine in a preferred direction across a surface of a panel. The method may furthermore include adjusting an orientation between the running gear and a cleaning unit of the cleaning unit in response to a hinderance to said moving. Other embodiments of this aspect include corresponding computer systems, apparatus, and computer programs recorded on one or more computer storage devices, each configured to perform the actions of the methods.

[0027] Implementations may include one or more of the following features. The method where said panel includes a solar panel and where said cleaning includes increasing an efficiency of said solar panel. The method where said hinderance includes a misalignment of a said cleaning unit with said preferred direction of movement. The method where said hinderance includes an obstacle in a path of said moving. The method where said hinderance includes a misalignment of said panel. Panel. The method where adjusting includes rotation of the running gear with respect to the cleaning unit within a plane of a face of the panel. The method where said rotation is in a plane of a face of the panel. The method where the running gear includes a support wheel resting on a face of said panel, the method may include support a portion of a weight of said cleaning machine normal to a face of said panel. The method where said support wheel is a neutral wheel. The method where said adjusting is via a swivel caster. The method further including driving said moving with said running gear. The method where said running gear includes a support wheel and where said driving is of said support wheel. The method powering said driving with a pressurized water. The method where a source of said pressurized water includes a supply hose and where said hinderance includes drag of said supply hose against said moving. The method where said running gear includes a side support configured to run along an edge of the panel and where said retaining includes limiting longitudinal movement of the cleaning unit along a face of the panel via said side support. The method further including a top carriage and where said top carriage includes said side support and a normal support, the method further including supporting at least partially a component of a weight of the cleaning assembly perpendicular to a face of the panel with said normal support. Implementations of the described techniques may include hardware, a method or process, or a computer tangible medium.

[0028] DESCRIPTION OF SPECIFIC EMBODIMENTS OF THE INVENTION

[0029] The present invention, in some embodiments thereof, relates to a system and method for cleaning solar panels and, more particularly, but not exclusively, to a robot for cleaning solar panels configured to withstand deviations in field geometry,

[0030] OVERMEW

[0031] Introduction to Solar Panel Cleaning Machines

[0032] An aspect of some embodiments of the current invention relates to a system and method for cleaning solar panels. Some embodiments relate to a machine for cleaning solar panels configured to withstand deviations in field geometry. Optionally, the cleaning machine may be water-driven. Additionally, the solar panels may be arranged in an array.

[0033] In some embodiments an automatic solar cell cleaning machine is designed to maintain the efficiency of photovoltaic panels by removing dust dirt bird droppings and other debris that accumulate on the surface. In some cases, a cleaning machine may also be referred to as a robot. For example, a cleaning machine may operate as a rail-mounted and / or self-driving robot that traverses along rows of solar panels. These machines typically use jets, nozzles, or fine mist sprayers to apply water across the surface of the panels, which is then wiped with soft brushes or wipers to remove accumulated dust and dirt. Some systems are fully integrated into the solar farm’s infrastructure with permanent piping, while others are mobile cleaning robots equipped with their own water tanks, allowing flexible deployment across multiple panel arrays.

[0034] To navigate effectively across solar panels, various embodiments may employ running gear. The running gear may include a variety of support and / or guide configurations. For example, the running gear may include a normal support that runs across a face of the solar panel and / or supports a portion of the weight of the machine normal to the face of the panel. Optionally, the normal support may include carts and / or support wheels and / or a continuous track configured to roll across the glass surface of a solar panel. Optionally, the running gear may include carts and / or wheels. In some embodiments, the running gear may include a side support and / or a normal support. For example, the normal support may support a portion of the weight of the machine normal to the face of the panel. For example, the side support may retain the position of the cleaning machine along the face of the panel and / or support a portion of the weight of the machine parallel to the face of the panel. In some embodiments, the side support and / or the normal support may include wheels, linear tracks, and / or rails. For example, rails may be mounted along the panel edges. Alternatively or additionally, the cleaner may use a continuous tread (e.g., similar to those of a small excavator).

[0035] Powering these water-based cleaning machines may employ electric motors. Alternatively or additionally, hydraulic motors may be used. Hydraulic motors may be advantageous in heavy-duty cleaning systems and / or in rugged utility-scale solar farms. Hydraulics provide high torque and durability, which is advantageous for moving larger systems and / or powering multiple cleaning brushes and water pumps simultaneously. Hybrid systems also exist, combining electric drive for locomotion with hydraulic assistance for brush and pump operation. In practice, the selection between electric and hydraulic power depends on the scale of the solar farm, the availability of maintenance staff, and the frequency of cleaning required. For example, desert-based solar farms where daily or weekly cleaning is critical may opt for rugged hydraulic systems with track-based guidance, while smaller rooftop setups benefit from compact electric wheeled cleaning robots that can be operated on demand.

[0036] In some embodiments, the solar panels may be arranged in one or more rows. For example, a row may include a plurality of similar solar panels, each panel arranged with its length perpendicular to the row. Optionally, each solar panel along its length may be angled with respect to the horizontal direction, for example, to increase the exposure of the face of the panel to the sun. Commonly, a solar panel may have a length of about two meters. Optionally, the machine progresses along a row, cleaning a row and / or a number of rows as it progresses. For example, the progress along the row may be automatic and / or robotically controlled. Optionally, the solar panel (e.g., row of solar panels) may be tilted at a slight angle a, which may facilitate that the solar panel receives the incoming solar radiation throughout the day through the various seasons.

[0037] In some cases, one cart on one side of a solar panel may lag relative to a cart on the other side of the solar panel. For example, in a rigid cleaning machine, this may cause the entire cleaning machine (cleaning unit and carts) to deviate from the direction of movement. These deviations may result in a fall from the row of solar panels and / or stopping the cleaning machine’s movement, e.g., as a result of a clamping effect. For example, such lags and / or deviations may be caused as a result of sliding, some obstacle, or any other reason.

[0038] In some embodiments, side supports may be included in a driving cart (the upper cart) of the robot. For example, side supports may inhibit the cleaning machine from sliding off the tilted solar panel due to the weight component W sin a of the machine.

[0039] Exemplary Dimensions and Weights

[0040] According to some embodiments, the cleaning machine may be configured to clean a row of solar panels whose width is greater than the length of one solar panel (e.g., about 2 m), such as a row consisting of 2, 3, or 4 solar panels (e.g., having a width of about 4 m, 6 m, 8 m, etc.). According to some embodiments, the weight component (W sin a) of the cleaning machine may range between about 10 kg to about 15 kg and / or about 15 kg to about 20 kg, about 20 kg to about 50 kg e.g., for a machine of between 6-8 m.

[0041] According to some embodiments, the cleaning unit may consist of one or more modules. Optionally, each module may cover one solar panel (e.g., about 2 m in length). Optionally, a middle cart may be located between every 2 modules. Optionally, a cleaning unit may include 1, 2, 3, 4, etc. modules. Optionally, the middle cart may be driven in a synchronized manner to the driving cart.

[0042] Optionally, the middle cart may be driven in a synchronized manner to the driving cart through the axis of the cleaning unit. Optionally, the axis of the cleaning unit may serve as the axis about which the brush is built and / or as a shaft that drives the wheels of the middle cart connected to it. Optionally, the mechanical system that transfers power from the brush shaft to the wheels of the drive cart may have the same gear ratio and / or operational method as the transmission in the driving cart.

[0043] Structural Components of a Solar Panel Cleaning Machine

[0044] Cleaning Units

[0045] In some embodiments, a machine designed for cleaning solar panels may include one or more modules. For example, for a solar array with multiple rows, the machine may include a module for each row of the array. For example, a top end extreme module may pass along the top row of the array, a middle module may pass along an intermediate row of the array, and / or a bottom extreme module may pass along a bottom row of the array. The modules may optionally progress together along the array.

[0046] Optionally, a module may include one or more cleaning units and / or one or more carts. Some cleaning units (e.g., an extreme unit) may include a side support. Herein, a cleaning unit refers to the components that clean the face of a solar panel. Optionally, a longitudinal axis of the cleaning unit may run along the length of a solar panel. For example, the cleaning unit may include a brush unit. Optionally, a set of cleaning units may be connected axially by link rods.

[0047] Normal Supports

[0048] In some embodiments, a cart may support a cleaning unit and / or a portion of a cleaning unit over the face of the solar panel. Optionally, the cleaning unit may be supported on the face of a solar panel by carts and / or support wheels. For example, support wheels may include drive wheels (e.g., wheels used to propel the cart along the panel). For example, a drive wheel may be connected to a drive system and / or propel the machine laterally along a panel and / or a row of panels. Support wheels may include neutral wheels (e.g., idler wheels that passively support the machine but do not contribute to propulsion). Optionally, support wheels may be connected to a cart and / or support wheels may be directly connected to a cleaning unit and / or another element of the machine.

[0049] In some embodiments, a module may include a cleaning unit with an extreme cart at each end. For example, each cart may support one end of the cleaning unit above the face of the panel. Carts may be driven or neutral. Optionally, driven carts are synchronized along the machine. For example, synchronization may be via an axis of the cleaning units. Optionally, synchronization contributes to the uniform movement of the robot.

[0050] Side Supports

[0051] In some embodiments, a top extreme cart will have drive wheels. For example, the top extreme cart may include drive support wheels and / or a side wheel. For example, the side wheel on a top cart may hold the cleaning machine from sliding down the panel. Optionally, a bottom extreme cart will have drive wheels. For example, the bottom extreme cart may include drive support wheels and / or a side wheel. For example, the side wheel on a bottom cart may preserve the orientation of the cleaning machine along the longitudinal axis of the panel. Alternatively or additionally, an extreme cart may include a neutral support wheel.

[0052] "Side supports" are configured to maintain the position of the cleaning machine relative to the solar panels. For example, a top side support may prevent the robot from sliding off tilted panels. For example, a bottom side support may encourage a desired orientation of the machine along the length of a panel. Passage of the side supports over an obstacle and / or step may tilt the entire robot and / or divert the robot from its path.

[0053] Machines with Multiple Cleaning Units

[0054] According to some embodiments, the cleaning machine may include one or more carts connected by one or more cleaning units. Optionally, the carts and cleaning units may be connected axially by link rods. Optionally, the carts, link rods, and cleaning unit may be one rigid unit. Optionally, the cleaning unit may include the link rods and the brush.

[0055] Articulated Connections

[0056] In some embodiments, the support of a cleaning machine may be configured to withstand various hinderance. For example, hinderances may include obstacles in a path of movement, misaligned panels and / or misaligned portions of the machine (e.g., cleaning units that are misaligned to the panel). For example, an articulated connection between a cleaning unit and running gear may facilitate a desired motion of the machine even cleaning unit becomes misaligned to the solar panel and / or another unit of the machine). For example, an outer cart (e.g., extreme cart) may be connected to a cleaning unit with a connection which allow the outer carts and / or wheels to pivot in the plane of the face of the panel with respect to the cleaning unit.

[0057] In some embodiments, interconnections between components are designed to facilitate the machine’s stability and / or continuous movement along the solar panels. For example, freedom of movement of articulated connections between the cleaning units and the carts, and freedom of movement of articulated connections between modules and / or between a cleaning and wheel and / or between a cleaning unit and a side support and / or between a normal support and a side support may reduce deviation and jamming. For example, articulated connection may be able to rotate over a range of 0 to 2 degrees and / or over a range of 2 to 5 degrees and / or over a range of 5 to 10 degrees and / or over a range of 10 or more degrees.

[0058] Articulated Connections to Normal Supports

[0059] In some embodiments, a cleaning machine may include flexible articulated connections. Optionally, flexible connections between a cleaning unit and carts allow for a degree of axial rotation within the plane of the panels. This design feature may facilitate carts preserving a direction of movement and / or a preferred path even if there is a misalignment of cleaning units and / or obstacles. Optionally, link rods and a brush form a single rigid cleaning unit which is flexibly connected to the carts.

[0060] "Extreme carts" are the carts located at the ends of the machine. In some embodiments, extreme carts may be configured to allow articulation of the wheels and / or the cart with respect to the extreme cleaning unit. For example, the cart may be connected to the cleaning units via a connection that allows rotation in the plane of the solar panels. Rotation of the cart and / or wheels may help maintain the direction of movement of the robot along the row of solar panels even if there is a mis-synchronization between the progress of the carts on either side due to obstacles or other reasons. Optionally, the system may include "Middle carts" positioned between cleaning modules. Middle carts may support the cleaning unit and / or facilitate directional stability. Optionally, the cleaning unit may be rigid. Optionally, the cleaning unit may be connected to a cart by an articulated connection. Optionally, the articulated connection may have a degree of rotation in the plane of the solar panels. Optionally, the side supports of the cart may include a degree of rotational freedom.

[0061] According to some embodiments, an added degree of freedom may prevent the cart from deviating from the direction of movement on the ends of the solar panels in the row, in some cases even when there is a mis-synchronization between the progress of the cart on one side of the row of panels and the progress of the cart on the other side of the row of solar panels.

[0062] In situations where one cart lags behind the other while the cleaning unit may be angled to the direction of movement, flexible connections between the carts and the cleaning unit may allow a cart to rotate with respect to the cleaning unit and / or to remain aligned in the direction of movement. Optionally, this allows the cart to continue moving straight in the preferred direction and / or without deviating from a track. This may be a significant improvement over rigid robots, which may deviate from the track and potentially fall off the panels or stop moving due to a clamping effect.

[0063] In some embodiments, a cleaning machine incorporates a universal joint to connect the drive shaft across cleaning units and / or across carts and / or between a cleaning unit to a cart. For example, a universal joint may connect a drive shaft of a cart to a brush shaft of a cleaning unit. This facilitates the brush unit in receiving rotary motion and / or driving wheels while accommodating the inclination between the drive shaft axis and the brush shaft axis. In some embodiments, the drive shaft is driven by a water motor through a gear system.

[0064] When it comes to cleaning rows of solar panels that are wider than a single panel (e.g., approximately 2 meters), multiple modules may be used. Optionally, each module covers one panel. In some embodiments, a middle cart is placed between modules.

[0065] In some embodiments, the middle carts are driven in a synchronized manner. For example, power may be directed to the wheels using a drive shaft of the carts and / or brush shaft of a cleaning unit. A transmission may be supplied between the brush shaft and the driven wheels. A connection between the cleaning unit and the two extreme carts may be flexible (e.g., allowing for a degree of rotation in the plane of the panels to prevent deviation if there is a misalignment of the cleaning panels). The driven middle carts optionally contribute to the uniform progress of the cleaning machine. Alternatively or additionally, a middle cart may be neutral (e.g., include an unpowered idle wheel or free wheel). For example, each middle cart includes two neutral wheels designed to support the cleaning unit between each pair of carts. Optionally, the neutral wheels feature a steering rotation axis allowing them to turn right or left in the plane of the solar panel. For example, the pivot may be translated away from the wheels, creating a caster effect. For example, the wheels may realign with the direction of movement even if a module is out of alignment. For example, frictional force between the neutral wheels and the panels may create a restoring torque helping to maintain the wheels' alignment with the direction of progress. For example, the wheels may be able to rotate over a range of 0 to 2 degrees and / or over a range of 2 to 5 degrees and / or over a range of 5 to 10 degrees and / or over a range of 10 or more degrees.

[0066] Articulated Connections to Side Supports

[0067] According to some embodiments, the cleaning machine may include side supports. For example, the side support may include side wheels running along the top edge of a solar panel and / or along the top edge of a row of solar panels. Optionally, the side support may inhibit the machine from sliding down a tilted face of a solar panel.

[0068] In some cleaning machines (e.g., with side wheels rigidly connected to the machine), when the side wheels pass over an obstacle and / or pass over a step, they may cause a deviation in the movement of the cleaning machine. For example, deviation of movement of the side wheels may tilt the entire cleaning machine and / or divert the cleaning machine from its path. For example, the obstacle may be a misalignment between adjacent solar panels and / or an object, etc. A degree of freedom may be added to the side wheels (rotation axis).

[0069] In some embodiments, a side support may include a degree of freedom allowing it to pass obstacles with reduced deviation of the robot from its path. For example, a side support may include a side wheel mounted on an arm that can rotate with respect to the axis of the cleaning unit. For example, the arm may be able to rotate over a range of 0 to 2 degrees and / or over a range of 2 to 5 degrees and / or over a range of 5 to 10 degrees and / or over a range of 10 or more degrees. This rotation may allow the side support to pass over an obstacle with reduced deviation of the position of the cleaning unit and / or the cleaning machine. For example, this reduced deviation may reduce the need to overcome the weight component (W sin a) of the machine in order to continue forward in the direction of movement.

[0070] In some embodiments of the current invention, a degree of freedom may be added to the side supports to allow the side supports to climb a step and / or pass over an obstacle with reduced deviation of the cleaning machine from its path. Optionally, the side supports may rotate about the rotation axis to adjust an orientation with respect to a cleaning unit and / or an angle with respect to the solar panel (e.g., slightly lift the side support over an obstacle or step) while the cleaning machine continues forward in the direction of movement.

[0071] According to some embodiments, a side support system may be mounted on a rotation axis. Optionally, the rotational axis may connect the side wheel to a cart of the cleaning machine and / or to a cleaning unit. Optionally, the rotational axis may connect the side support system to the cleaning machine using a dedicated bracket used to fix the side supports to the driving cart. Alternatively or additionally, a side support may include a side wheel having an individual suspension that allows it to move with respect to the cleaning machine, for example, when traversing a step and / or an obstacle.

[0072] In some embodiments, one portion (e.g., one module) of a cleaning machine may move faster than another. For example, an unhampered driving cart may move faster than a driving cart pulling a water supply hose. Optionally, the system may include an elastic connection to side supports configured to provide a restoring moment (e.g., pulling the machine to align perpendicular to the edges of the panel). For example, the elastic connection may include an elastic suspension on the side supports (e.g., springs).

[0073] In summary, the articulated connections within the cleaning machine, including those to normal supports and side supports, provide the necessary degrees of freedom to navigate obstacles, maintain alignment, and ensure continuous, efficient cleaning of solar panels. The integration of these features supports the claims for a cleaning machine capable of overcoming misalignments, obstacles, and other hindrances while maintaining the desired path and cleaning efficiency.

[0074] SPECIFIC EMBODIMENTS

[0075] Before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not necessarily limited in its application to the details of construction and the arrangement of the components and / or methods set forth in the following description and / or illustrated in the drawings and / or the Examples. The invention is capable of other embodiments or of being practiced or carried out in various ways. Reference is now made to the figures.

[0076] Fig. 1 is a schematic diagram illustrating a solar panel 10 and cleaning machine 13, in accordance with some embodiments of the current invention. In the exemplary embodiment, there is a single row of solar panels 10 and the machine 13 includes one module. Optionally, the module includes a cleaning unit 14. The machine 13 includes normal supports. For 4example, the normal supports include a top support cart 18a and a bottom support cart 18b. and a cleaning unit 14. Optionally, each cart 18a, 18b runs laterally across the panel 10 on support wheels 17. Optionally, support wheels 17 of both the upper cart 18a and lower cart 18b are powered (drive wheel).

[0077] For example, a solar panel 10 (e.g., one of a row of solar panels) is tilted at an inclination angle a. Optionally, solar panel 10 is supported by frame 12. Angle a may be selected to increase the exposure of solar panel 10 to solar radiation (e.g., throughout the day and / or through the various seasons). The inclination angle depends on the latitude (e.g., in Israel, the latitude is 32°, the inclination angle is generally chosen as approximately 15°). Additionally or alternatively, solar panels 10 are inclined at inclination angle a for additional reasons, such as constructive reasons, compliance with wind standards, self-cleaning by rain, preventing water from pooling on the solar panel, avoiding shading of adjacent panels etc.

[0078] In some embodiments, carts 18a and 18b and / or support wheels 17 support a component 19 of the weight (W) 11 of the cleaning unit 14 perpendicular to the face of the solar panel 10 (e.g., W cos a where W is the weight 11 of the machine 13).

[0079] In some embodiments, a side support (e.g., side wheels 16) is included in upper cart 18a of cleaning machine 13. For example, side wheels 16 may inhibit the cleaning machine 13 from sliding off solar panel 10 due to the component 15 of the weight 11 of the cleaning machine 13 parallel to the face of the solar panel (e.g., W sin a). For example, the weight W 11 of machine 13 may be about 15-20 kg in the cleaning machine of 6-8 meters length. Side wheels 16 optionally, maintain the position of machine 13 relative to solar panels 10 on the Y axis (parallel to the face of the solar panel and / or perpendicular to the cleaning machine's lateral axis of advancement across the solar panel and / or row). Alternatively or additionally, a side support may be including in a botom cart 18b. For example, a lower side support may include a lower side wheel. For example, tension between the upper side wheel 16 and the lower side wheel may help preserve the orientation of the machine 13 perpendicular to the lateral direction of movement.

[0080] Figs. 2A-D are schematic diagrams illustrating a rigid cleaning machine 19a (Figs. 2A, 2C) and a cleaning machine 19b (Fig. 2B, 2D) which allow'S rotation between a cleaning unit (e.g., brush unit 24) and a normal support (e.g., carts 20 and 25), in accordance with some embodiments of the current invention. In the exemplary embodiment, the cleaning machine is meant to travel in a lateral direction of travel (in the direction of the x-axis).

[0081] In the exemplary embodiment of Figs. 2A and 2C, the cleaning machine 19a is rigid. For example, the cleaning unit 24, link rod 22 and normal support (e.g., the carts 20, 26) are one rigid unit. The carts 20, 26 and cleaning unit (e.g., cleaning unit 24) may be connected axially by a link rod 22. The system works well when the cleaning unit 24 is aligned with the Y-axis, perpendicular to the direction of travel (e.g., the brush is directed along the length of the solar panel 30) as illustrated in Fig. 2A.

[0082] When one cart 26 on one side of solar panel 30 were to lag relative to the cart 20 on the other side of solar panel 30 then the cleaning unit 24 becomes out of alignment (in the exemplary’ embodiment cleaning unit 24 is not aligned with the y-axis, perpendicular to the direction of the x-axis as illustrated for example, in Figs. 2C and 2D).

[0083] In a rigid cleaning machine 19a, the carts 20 and 26 wheels 21 are constrained to remain perpendicular to the axis of cleaning unit 24. Accordingly, when the cleaning unit 24 deviates from its orientation perpendicular to the direction of movement, the carts 20 and 26 and the wheels 21 deviated from the lateral direction of travel (parallel to the x-axis). As a result, in some cases, the entire machine may deviate to the side and / or fall from the row of solar panels 30. In other cases, (for example, when the support wheels 21 are running on a track 23) the deviation from the direction of travel will stop progress of the machine 19a, e.g., as a result of a clamping effect between the wheels and the track 23.

[0084] In the exemplary' embodiment of Figs, 2B and 2C, the cleaning machine 19b is flexible. For example, the cleaning unit 14 unit may be connected to carts 20, 26 and support wheels 21 by articulated connections 28. Articulated connection 28 may have a degree of axial rotation in the plane of solar panels 30. For example, the carts may be able to rotate over a range of 0 to 2 degrees and / or over a range of 2 to 5 degrees and / or over a range of 5 to 10 degrees and / or aver a range of 10 or more degrees. Optionally, the side wheels 21 of the cart may include a degree of rotational freedom. When one cart 26 on one side of solar panel 30 were to lag relative to the cart 20 on the other side of solar panel 30 for some reason, articulated connections 28 adjusts an angle between carts 20, 26 on the cleaning units (e.g., cleaning unit 24) of the solar panel. Thus, even when the cleaning machine 19b and / or cleaning unit 24 is misaligned with the direction of travel (e.g., is not oriented along the length of the panel (parallel to the y-axis) and / or is not perpendicular to the lateral direction of travel (e.g., the x-axis)) the carts 20 and 26 and / or support wheels 21 remain oriented in preferred the direction of travel (e.g., laterally along the panel 30 parallel to the x-axis). In some embodiments, this facilitates the continuous straight movement of cleaning machine 19b including carts 20, 26 in the direction of movement even when the cleaning machine 19b and / or cleaning unit is misaligned with the direction of travel.

[0085] Advantageously, according to some embodiments, the added degrees of freedom may prevents the cart from deviating from the direction of movement on the ends of the solar panels in the row' if there is a ims-synchronization between the progress of the cart on one side of the row' of panels and the progress of the cart on the other side of the row of solar panels as a result of sliding, some obstacle or any other reason.

[0086] Figs. 3A-D are schematic diagrams illustrating an articulated connection between a cleaning unit 40 and normal support (e.g., a cart 34), in accordance with some embodiments of the current invention. For example, the articulated connection between the cart 34 and the cleaning unit 40 may include a revolute joint. For example, a hinge pin 32 connects an eye channel 33 through cleaning unit 40 to a bearing 31 on the cart 34. The articulated connection may facilitate cleaning unit 40 rotating relative to the direction of movement of cart 34. For example, the connection between cart 34 and cleaning unit 40 may allow mutual pivoting around hinge pin 32. Optionally, this may allow the direction of movement of cart 34 to continue in a preferred direction even when the cleaning unit becomes misaligned.

[0087] In some embodiments, cart 34 will include support wheels 35. For example, support wheels may run along a face of a solar panel and / or support a portion of the weight of cart 34 and / or cleaning unit 40. For example, the support wheels 35 may support a portion of the normal component of the weight of cart 34 and / or cleaning unit 40 normal to the face of the solar panel. Optionally, support wheels 35 are configured to roll laterally across a face of a solar panel. Optionally, cleaning unit 40 is configured to be oriented with its longitudinal axis perpendicular to the lateral direction of the panel. For example, the support wheels 35 may be oriented to roll in a direction perpendicular to the longitudinal axis of the cleaning unit 40. In some embodiments, the cleaning unit will include an elongated brush having a longitudinal brush axis and / or brush shaft 44 directed along the longitudinal axis of the cleaning unit.

[0088] In some embodiments, the robot may include drive wheels. For example, support wheels 35 are driven by a water motor 42. Optionally, a drive shaft of the motor 42 and / or cart 34 is connected to a brush may be a universal joint 38 (e.g., universal coupling, U-joint, constant- velocity joint, Rzeppa joint, tripod joint, double cardan joint, etc.). Universal joint 38 may connect a drive shaft of motor 42 and / or cart 34 with the brush shaft 44 (e.g., link rod). Optionally, universal join 38 passes rotation motion between cart 34 and brush shaft 44 brush shaft 44 and / or cleaning unit 40 is inclined with respect to cleaning to the cart 34 and / or drive shaft axis of motor 42. Optionally, motor 42 may be driven by the passage of water through a gear system.

[0089] In some embodiments, cart 34 includes a sides support (e.g., side wheels 36). Optionally, side wheels 36 are mounted on side wheel arms 37. Side wheels 36 may facilitate maintaining the position of the cleaning machine relative to the solar panels. For example, side wheels 36 are be oriented for lateral travel along the edge of the solar panel and / or perpendicular to the support wheels 35 and / or perpendicular to the axis of the cleaning unit 40. This orientation may be modified dependent on the articulation of the side wheel arms 37,

[0090] In some embodiments, the side wheel arms 37 may be cantilevered beams. Additionally, the side wheel arms 37 may be articulated. Articulation may facilitate the side wheels 36 passing over obstacles, such as misaligned panel edges. This articulation allows the cart 34 and / or cleaning unit 40 and / or support wheels 35 to maintain the desired orientation and position, even when side wheels 36 encountering obstacles and / or deviate from their linear lateral path. For instance, the side wheels 36 may be mounted on arms that can rotate with respect to the axis of the cleaning unit 40. This rotation can occur over a range of angles, such as 0 to 2 degrees, 2 to 5 degrees, 5 to 10 degrees, or even 10 or more degrees. This rotational capability allows the side wheels 36 to climb steps or pass over obstacles while minimizing deviation from the machine's intended path. In some embodiments, the side wheels 36 may be mounted on a rotation axis that connects them to the cart 34 or the cleaning unit 40. This rotational axis may be part of a dedicated bracket used to fix the side wheels 36 to the driving cart. Alternatively, the side wheels 36 may include individual suspensions that allow them to move independently with respect to the cleaning machine, providing additional flexibility when traversing steps or obstacles.

[0091] In some embodiments the side wheels 36 are configured to prevent the cleaning machine from sliding off tilted panels and / or to encourage a desired orientation along the length of a panel. For example, when cart 34 is a top cart, side wheel 36 may prevent the robot from sliding down a tilted face of a solar panel. Alternatively or additionally, for example when cart 34 is a bottom cart, side wheel may help maintain the machine’s alignment along the panel’s length.

[0092] The cleaning machine may also include an elastic connection to the side wheels 36, configured to provide a restoring moment that helps align the machine perpendicular to the edges of the panel. This elastic connection may include an elastic suspension on the side wheels 36, such as springs, which help maintain the machine’s alignment and stability’ during operation.

[0093] Figs. 4A and 4B are schematic diagrams illustrating various exemplary cleaning robots with multiple brush modules, having rigid middle carts in accordance with some embodiments of the current invention.

[0094] Optionally, a middle cart 52 is positioned between every’ two cleaning units 48. The middle cart 52 is driven in a synchronized manner with the driving cart through the axis of the cleaning unit 48. This cleaning unit 48 serves both as the axis on which the brush is built and as a shaft 56 that drives the middle wheels 51 of the middle cart 52 located behind it. The transmission between the brush shaft 56 and the driven middle wheels 51 of the middle cart 52 is designed to be identical to the transmission present in the driving cart. This facilitates consistent and reliable movement of the middle cart 52 in conjunction with the cleaning units 48. In some embodiments, middle wheels 51 are rigidly fixed in cart 52. For example, 36 may be fixed to travel at an angle perpendicular to the axis of the cleaning unit 48. In some embodiments the middle wheels 51 may be directly connected to the cleaning unit 48. In some embodiments, the cleaning unit 48 and / or the cart 52 may include a power source e.g., a hydraulic motor.

[0095] In some embodiments, the connection between the cleaning unit 48 (e.g., a rotating brush) and the two extreme carts 54 and / or 58, which include the driving cart and the secondary cart, is an articulated connection 60. This articulated connection 60 allows for a degree of rotation in the plane of the solar panels 50. This feature facilitates the two extreme carts 54 and / or 58 in maintaining the preferred path of progress on the panels, which is lateral to the solar panel 50. This may be particularly beneficial in cases where there is a miss- synchronization between the progress of the robot on one side of the row of panels and the progress of the robot on the other side. Such miss-synchronization may occur due to obstacles, sliding, or other reasons.

[0096] In some embodiments, when there is a lag in the progress of one side of the robot relative to the other side, the two extreme carts 54 and / or 58, due to the axial connection 60, will continue straight in the direction of the row of panels. Meanwhile, the middle cart 52, or middle carts in the case of more than two modules, e.g., in between the rigid cleaning units 48, will deviate from the original direction of movement 70. This deviation occurs in the direction of deviation 72. In some cases, driven middle carts 52 contribute to the uniform progress of the robot.

[0097] For example, in scenarios where the robot encounters an obstacle or experiences sliding, the articulated connection 60 allows the extreme carts 54 and / or 58 to maintain their lateral movement along the row of panels. This facilitates that the cleaning process continues effectively despite the deviation of the middle cart 52. This design provides a balance between maintaining uniform progress and adapting to unforeseen circumstances that may affect the movement of the robot.

[0098] In some embodiments, middle cart 52 may be driven in a synchronized manner to extreme carts 54 and / or 58. Optionally, middle cart 52 may be driven via brush shaft 56. Optionally, the brush shaft 56 may serve as the axis about which a brush revolves, cleaning the solar panel 50 and / or as a shaft that drives the middle wheels 51 of middle cart 52. Optionally, the mechanical system that transfers power from the brush shaft to the wheels of the drive cart may include a transmission. For example, the transmission may have the same gear ratio and / or operational method as the transmission in the extreme carts 54 and / or58.

[0099] Figs. 4C-4J are schematic diagrams illustrating various exemplary cleaning robots with multiple brush modules, having articulated middle carts in accordance with some embodiments of the current invention. In some embodiments, the cleaning machine may consist of several modules and / or brush units 48. Optionally, each module and / or brush unit 48 may cover one panel (e.g., about 2 m in length). The extreme ends of extreme brush units 46 may be connected by an articulated connection 60 to a normal support (e.g., the extreme carts 54 and 58). Articulated connection 60 may facilitate angular movement of the brush unit relative to cart 54 and / or cart 58. The normal support may include a middle cart 53. For example, middle cart 53 may be located between pairs of cleaning units 48 (e.g., between every two cleaning units 48). Optionally, a cleaning machine may include 1, 2, 3, 4, etc. modules. Optionally, the middle carts 53 may not be driven. Optionally, each cart may include includes 2 or more neutral wheels 62. Optionally, neutral wheels 62 may be configured to support the cleaning machine in the region between the brush units 48. The neutral wheels may include a steering rotation axis 64 (e.g., the neutral wheel may turn to the right and / or left). Optionally, the neutral wheels 62 may include a sliding mechanism 66. For example, sliding mechanism 66 may be configured to place the point of contact of the wheel with the solar panel 50 behind the rotation axis in accordance with the direction of movement 70. Optionally, this mechanism may facilitate directional stability of the neutral wheels 62 while moving in a particular direction. Optionally, the distance between the axis of rotation and the point of contact of the neutral wheels with the solar panels may result in the frictional force 68 between the neutral wheels 62 and the solar panels 50. Optionally, the frictional force 68 may create a restoring torque, which may aid in realigning the neutral wheels 62 to the direction of movement 70 (e.g., similar to a caster). For example, even when the middle cart / s 53 body deviates from the preferred direction (e.g., with its axis perpendicular to the direction of motion 70) along solar panels 50 neutral wheels 62 may remain stable and / or directed in the preferred direction of movement 70 (e.g., laterally along solar panels 50). Optionally, a brush unit 46 may include a driven middle cart and / or a non-driven middle cart. The nondriven middle cart may include one or more neutral wheels with a steering rotation axis and a directional stability system.

[0100] Fig. 5A is a block diagram illustrating an exemplary robot cleaning system, in accordance with an embodiment of the current invention. In some embodiments, the system 74 for cleaning solar panels includes a cleaning unit 82 and running gear 76 (e.g., a cart and or wheels and / or a continuous track). The cleaning unit 82 may be connected to the running gear 76 via an articulated connection 80. The running gear 76 is designed to maintain the cleaning unit 82 over the face of the solar panel, ensuring effective cleaning.

[0101] Optionally, the running gear 76 may be powered by a motor 88, which could be a water motor 88. This motor 88 may drive the running gear 76 along the surface of the solar panel, providing the necessary movement for the cleaning process. In some embodiments, the running gear 76 may include support wheels that rest on the face of the solar panel. These support wheels can be either drive wheels or neutral wheels. For example, the support wheels may be configured to support at least partially a component of the weight of the cleaning unit 82 perpendicular to the face of the solar panel.

[0102] The articulated connection 80 between the cleaning unit 82 and the running gear 76 may allow for a degree of axial rotation within the plane of the solar panels. This feature can enhance the maneuverability of the cleaning unit 82, allowing it to adapt to the contours and angles of the solar panel surface. In some embodiments, the articulated connection 80 may be a revolute joint, providing a specific type of rotational freedom.

[0103] Additionally, in some embodiments, the running gear 76 may include side wheels configured to run along the edge of the solar panel. These side wheels can limit the longitudinal movement of the cleaning unit 82 along the face of the solar panel, ensuring that the cleaning unit 82 remains aligned and does not deviate from its path. In some embodiments, the side wheels may be mounted on opposite sides of a rocker beam, providing stability and balance to the running gear 76. The side wheels may also be configured to support at least partially a component of the weight of the cleaning unit 82 parallel to the face of the solar panel.

[0104] Alternatively or additionally, the side wheels may include a rotational axis that facilitates the robot climbing a step or obstacle without deviating from its path. This feature can be particularly useful in environments where the solar panels are installed on uneven surfaces.

[0105] In some embodiments, the system 74 may include a secondary cart attached to the lower edge of the solar panel. The cleaning unit 82 may be connected to both the driving running gear 76 and the secondary cart via a brush shaft. The brush unit 82 may be a rigid unit, including one or more brush modules and one or more middle carts. The middle carts can be either driven or non-driven. Non-driven middle carts may include neutral wheels with a steering rotation axis and a directional stability system, enhancing the overall stability and maneuverability of the cleaning unit 82.

[0106] Optionally, the secondary cart may include spring-loaded side wheels, providing additional support and stability to the cleaning unit 82. These spring-loaded side wheels can help maintain the position of the cleaning unit 82 relative to the solar panel, ensuring consistent and effective cleaning.

[0107] In some embodiments, the articulated connection 80 may include a swivel caster with a limited range of rotation. This feature can provide additional flexibility and maneuverability to the cleaning unit 82, allowing it to navigate around obstacles and adapt to the contours of the solar panel surface.

[0108] Fig. 5B is a block diagram illustrating an exemplary robot cleaning system, in accordance with an embodiment of the current invention. For example, in system 84, cleaning unit 82 may be connected to running gear for example carts 86, 100 by articulated connections 90, 98. Optionally, driving cart 86 may be powered by the passage of water. Optionally, the cleaning unit 82 may be a rigid unit including a one or more cleaning units 96 and / or middle carts 94. The running gear may include a middle cart 94 which may be a driven middle cart and / or a non-driven middle cart. The non-driven middle cart may include one or more neutral wheels with a steering rotation axis and a directional stability system. Optionally, each cleaning unit 96 may include a brush and a link rod. Articulated connection 80 may have a degree of axial rotation in the plane of solar panels. Optionally, side wheels of the cart may include a degree of rotational freedom. When secondary cart 100 on one side of solar panel lags relative to driving cart 86 on the other side of solar panel for some reason, articulated connections 90, 98 adjust an angle between carts 86, 100 on the sides of the solar panel and brush unit 92, thereby facilitating the continuous straight movement of carts 86, 100 along the solar panel. Carts 86, 100 and / or the robot may continue straight in the preferred direction of movement.

[0109] Fig. 6 is a flow chart illustrating a method 102 for use of a robot cleaning system, in accordance with an embodiment of the current invention. The method illustrated in flow chart 6 involves a systematic approach to cleaning panels, specifically solar panels, using a specialized cleaning machine. The process includes retaining 103 the cleaning machine over the face of the panel. This retaining 103 is facilitated by running gear, which includes various support and guide configurations to ensure stability and proper alignment. The running gear may include normal support, for example support wheels that rest on the face of the panel, providing a portion of the weight of the cleaning machine normal to the panel's surface. Additionally or alternatively, retaining 103 may also include side supports. For example, side supports may retain 103 the cleaning machines longitudinal position along the face of a panel.

[0110] In some embodiments, the cleaning machine is moved 104 along the face of the panel and / or a row of panels. This movement is driven by the running gear, which may include drive wheels connected to a drive system. Optionally, the drive wheels propel the machine laterally across the panel, ensuring thorough cleaning of the entire surface. The movement is typically in a preferred direction, which lateral with respect to the panel.

[0111] During the movement of the cleaning machine, various hinderances may be encountered. These hinderances can include obstacles in the path of movement, misalignment of the cleaning unit with the preferred direction of movement, or misalignment of the panel itself. To address these hinderances, the method includes adjusting 106 an angle between the cleaning unit and the running gear. This is achieved through articulated connections that allow rotation within the plane of the face of the panel. These connections provide the necessary degrees of freedom to navigate obstacles and maintain alignment.

[0112] One common hinderance is the misalignment of the cleaning unit with the preferred direction of movement. This misalignment can cause deviation from the intended path and reduce cleaning efficiency. By adjusting 106 an angle between the cleaning unit and the running gear, the articulated connections allow the cleaning unit to realign with the preferred direction, ensuring continuous movement and effective cleaning. This adjustment is crucial for maintaining the machine's stability and preventing any clamping effects that could halt its progress.

[0113] Another hinderance that may be encountered is an obstacle in the path of movement. Obstacles can include physical objects on the panel or irregularities in the panel's surface. The articulated connections enable the cleaning machine to navigate these obstacles by allowing the running gear to pivot with respect to the cleaning unit. This pivoting action helps the machine to climb over obstacles or pass through irregularities without deviating from the intended path. This capability is essential for maintaining the machine's efficiency and preventing interruptions in the cleaning process.

[0114] Misalignment of the panel itself is another hinderance that can affect the cleaning machine's movement. Panels may be tilted or positioned at varying angles, which can cause deviations in the machine's path. For example, misalignment of the top or bottom of the frames of different panels may hinder movement of a side support. The articulated connections between the cleaning unit and the running gear allow for adjustments in the machine's orientation, accommodating the panel's angle and ensuring continuous movement. This flexibility is vital for cleaning panels arranged in rows with different orientations.

[0115] Powering the movement of the cleaning machine can be achieved using pressurized water. The pressurized water drives the running gear, providing the necessary force to propel the machine across the panel. This method of powering is advantageous for heavy-duty cleaning systems and rugged utility-scale solar farms. The supply hose for the pressurized water may create drag against the movement, which is another hinderance that can be addressed by the articulated connections. These connections allow the machine to adjust its orientation and continue moving despite the drag.

[0116] The running gear may include side supports configured to run along the edge of the panel. These side supports limit longitudinal movement of the cleaning unit along the face of the panel, ensuring that the machine remains aligned with the panel's edges. The side supports may include wheels or tracks that provide additional stability and prevent the machine from sliding off the panel. This feature may be particularly important for panels that are tilted, as it helps maintain the machine's position and prevents any lateral deviation.

[0117] In some embodiments, the cleaning machine may include a top carriage with side supports and / or normal supports. The top carriage supports a portion of the weight of the cleaning assembly perpendicular to the face of the panel, providing additional stability. For example, the side supports on the top carriage may inhibit the machine from sliding down the panel due to the weight component of the machine. Optionally, the orientation of the carriage to the cleaning unit may be adjusted 106. Optionally, the orientation of the side support to the cleaning unit may be adjusted 106. Optionally, the orientation of the side support to the carriage may be adjusted 106. This configuration ensures that the cleaning machine remains aligned with the panel's edges and continues moving in the preferred direction.

[0118] The articulated connections within the cleaning machine, including those to normal supports and side supports, provide the necessary degrees of freedom to adjust 106 the orientation between the running gear and the cleaning unit. This may facilitate navigating obstacles, maintaining alignment of the running gear, and / or maintaining continuous efficient cleaning of solar panels. These features facilitate a cleaning machine overcoming misalignments, obstacles, and other hinderances while maintaining the desired path and cleaning efficiency. The integration of these articulated connections and support mechanisms is essential for the effective operation of the cleaning machine in various field conditions.

[0119] Figs. 7A-B are schematic diagrams illustrating a rigid robot, in accordance with some embodiments of the current invention. For example, the cleaning robot may include a cleaning unit 112, link rod 118. Optionally, the cleaning unit is connected to running gear via an articulated connection to the running gear. For example, the running gear may include a normal support including carts 116, 120 and / or side wheels 114 as one rigid unit. The carts

[0120] 116, 120 and cleaning unit 112 may be connected axially by a link rod 118. Alternatively, or additionally, the cleaning unit 112, and link rod 118 may be one rigid brush unit.

[0121] When side wheels 114 are rigidly connected to the cleaning unit 112, passage of the side wheels 114 over an obstacle and / or step may tilt the entire robot and / or divert the robot from its path. The obstacle may be a misalignment between adjacent solar panels and / or an object, etc.

[0122] Figs. 7C is a schematic diagram illustrating a flexible robot, in accordance with some embodiments of the current invention. A degree of freedom may be added to the side wheels 1 14. For example, an articulated connection (a rotation hinge 122) may be added between the side wheels 114 and cart 116, For example, in the embodiment of Fig. 7C, sides wheels 114 run along the edge of the panels 110. The side wheels 114 are mounted on a rocker beam 117. Optionally, rocker beam 1 17 is mounted on a hinge 122 allowing rotation of the rocker beam

[0123] 1 17. For example, rotation of the rocker beam 117 allow relative raising and lowering of side wheels 114 with reduced or no change in orientation of the cart 116 and / or cleaning unit 112. Optionally hinge 122 is located approximately in the center of the rocker beam 117 and / or bisects between the side wheels 114. In some embodiments, the rocker beam 117 may be free to rotate over a range of 2 degrees and / or over a range of 5 degrees and / or over a range of 10 degrees and / or over a range of 30 degrees.

[0124] A degree of freedom may be added to the side wheels 1 14 (rotation hinge 122) to allow the robot to continue closer to a preferred path and / or preferred orientation while the side wheels 114 climb a step and / or obstacle. For example, as side wheels 114 traverse and obstacle, hinge 122 rotates reducing deviation of the robot from its path. Side wheels 114 may rotate about rotation hinge 122 to open an angle with respect to solar panel 110 to slightly lift the driving cart 116 while the robot continues forward in the direction of movement. Side wheels 114 climbing the obstacle and / or step may overcome a component of the robot's weight W sin a and / or the torque developed by this component against the deviation. Side wheels 114 open an angle by rotation about rotation hinge 122, slightly lifting the driving cart, against the weight component W sin a, whereby the rotation about the rotation axis facilitates moving the robot forward in the direction of movement (X axis).

[0125] Advantageously, according to some embodiments, the added degrees of freedom may prevents the cart from deviating from the direction of movement on the ends of the solar panels in the row if there is a mis-synchronization between the progress of the cart on one side of the row- of panels and the progress of the cart on the other side of the row' of solar panels as a result of sliding, some obstacle or any other reason.

[0126] Figs. 8A-C are schematic diagrams illustrating a side support system for use with a cleaning robot, in accordance with some embodiments of the current invention. Fig. 8A illustrates the side support system detached from the driving cart. Fig. 8B and Fig. 8C illustrate the side support system attached to the driving cart from various perspective views.

[0127] For example, the cleaning robot may include a brush with a link rod, carts, support wheels 115. Driving cart 130 may include side wheels 134. For example, side wheels 134 may be mounted perpendicular to support wheels 115. If side wheels 134 were mounted rigidly to the cleaning unit and / or drive cart than when sides wheels 115 pass over an obstacle and / or step the support wheels and / or the entire robot may be tilted and / or diverted its preferred path. In some cases (e.g., when support wheels 115 run over a track 119) the system to jam (e.g., as support wheels are jammed against the track 119). The obstacle may be a misalignment between adjacent solar panels and / or an object, etc.

[0128] In some embodiments, a degree of freedom may be added to the side wheels 134. A degree of freedom may be added to the side wheels 134 by and articulated coupling (e.g., hinge 124). Hinge 124 may facilitate the side wheels 134 climbing a step and / or obstacle with reduced deviation of the robot (e.g., a cleaning unit and / or cart 130) from its path. Side wheels 134 may rotate about hinge 124 to open an angle with respect to the solar panel to slightly lift the driving cart 130 while the robot continues forward in the direction of movement. Side wheels 134 climbing the obstacle and / or step may overcome a component of the robot's weight W sin a and / or the torque developed by this component against the deviation. Side wheels 134 open an angle by rotation about hinge 124, slightly lifting the driving cart, against the weight component W sin a, whereby the rotation about the rotation axis facilitates moving the robot forward in the direction of movement (X axis).

[0129] Side wheel system equipped with a rotational hinge 124 may include a permanently fixed bracket 128 connected to the driving cart 130, a rotational hinge 124 and a side wheel arm 126. Optionally, the side wheels may be mounted to the side wheel arm 126. The side wheel arm 126 may include a hinge 124. For example, side wheel arm 126 may have the form of a rocker beam rotating around hinge 124 which is located between the side wheels 134. Optionally, the rotational hinge 124 may connect the side wheel system to driving cart 130. Optionally, the rotational hinge 124 may connect the side wheel system to driving cart 130 using the dedicated bracket 128, which may be used to fix the side wheels 134 to driving cart 130. Optionally, driving cart 130 may be powered by a water motor 132. Optionally, the drive cart 130 includes a hose fitting 127, For example, cart 130 may receive pressurized water that drives the drive wheels 115 and / or supplies cleaning water. For example, exhaust water from the to connect to a water source

[0130] Figs. 9A-D are schematic diagrams illustrating a robot cleaning system, in accordance with some embodiments of the current invention. For example, driving cart 142 may include side wheels 136. Passage of the side wheels 136 over an obstacle and / or step may tilt the entire robot and / or divert the robot from its path. The obstacle may be a misalignment between adjacent solar panels and / or an object, etc. A degree of freedom may be added to the side wheels 136. A degree of freedom may be added to the side wheels 136 by rotation axis 140. Rotation axis 140 may facilitate the side wheels 136 climbing a step and / or obstacle without deviating the robot from its path. Side wheels 136 may rotate about rotation axis 140 to open an angle with respect to solar panel 144 to slightly lift the driving cart 142 while the robot continues forward in the direction of movement. Side wheels 136 climbing the obstacle and / or step may overcome a component of the robot's weight W sin a and / or the torque developed by this component against the deviation. Side wheels 136 open an angle by rotation about rotation axis 140, slightly lifting the driving cart, against the weight component W sin a, whereby the rotation about the rotation axis facilitates moving the robot forward in the direction of movement (X axis).

[0131] Side wheel system equipped with a rotational axis 140 may include a permanently fixed bracket (not shown) connected to the driving cart 142, a rotational axis 140 and a side wheel arm 138. Optionally, the side wheels 136 may be mounted to the side wheel arm 138. The side wheel arm 138 may include a rotation axis 140. Optionally, the rotational axis 140 may connect the side wheel system to driving cart 142. Optionally, the rotational axis 140 may connect the side wheel system to driving cart 142 using the dedicated bracket (not shown), which may be used to fix the side wheels 136 to driving cart 142. Optionally, driving cart 142 may be powered by a water motor 156.

[0132] The rate of forward movement rate of the carts (driving cart 142 and secondary cart 152) may not always the same, even when the robot is moving in a straight line without any obstacles, and even though the carts are driven simultaneously via the brush shaft of cleaning unit 146. Optionally, the difference in the rate of forward movement may be due to slip and / or drag forces acting on the driving cart 142 which pulls a pressurized water supply hose (not shown). Optionally, the hose may be full of water at working pressure, which may exert a force, a drag. Optionally, the drag force may range between about 5 kg to about 10 kg, and / or about 10 kg to about 15 kg, and / or about 15 kg to about 30 kg. A deviation angle P may develop since the secondary' cart 152 may move faster than the driving cart 142 pulling the water supply hose. The system may include a side support which applies a restoring force. For example, the side support may include an elastic member that tends to pull the cleaning machine to its preferred orientation (e.g,, longitudinally along the panel). For example, spring-loaded bottom side wheels 148 may pull against axially restoring the robot to is preferred longitudinal orientation. The spring-loaded side wheels may include a spring 150 biased towards solar panel 144 configured to provide a restoring moment in the direction opposite to the deviation angle p. Additionally, or alternatively, the weight component in the plane of the solar panels (W sin a) may provide a restoring moment in the direction opposite to the deviation angle p. In some embodiments, the side wheels are mounted on an arm 154 and / or a cantilever beam connected to a bottom extreme cart 152.

[0133] In some embodiments, a system may include multiple degrees of freedom. For example, side wheels with a spring A longer robot may be composed of multiple and / or heavier modules. Optionally, the need for sprung-loaded side wheels on the secondary cart 152 in longer robots (e.g., I, 2, 3, 4, etc. solar panels in length) may be eliminated due to the weight of the longer robot. Optionally, fixed side wheels 148 which are not in constant contact with the solar panel 144 may be used to limit the size of the deviation angle P which may develop. As the robot becomes longer (e.g., composed of multiple cleaning units 146) and heavier, the restoring torque resulting from the weight component in the plane of the solar panels (W sin a) may be greater, since for the same deflection angle P, W is larger and L is larger. Optionally, the need for spring-loaded side wheels 148 on the secondary cart 152 may be smaller. Optionally, driving cart 142 and / or secondary cart 152 may include fixed side wheels 136 which are not in contact with the solar panel 144. Optionally, the non-contacting side wheels 148 may serve as a type of constraint for the deflection angle p which may develop.

[0134] Fig. 10 is a block diagram illustrating an exemplary side support system, in accordance with an embodiment of the current invention. In some embodiments, a side support 158 is an of a cleaning robot 162 may be designed to enhance the robot’s ability to navigate and clean surfaces efficiently. In some embodiments, the side support is connected to the cleaning robot via an articulated connection 160. This connection allows for a degree of flexibility and movement, may facilitate maintaining the robot's alignment and path, especially when encountering obstacles or irregularities on the cleaning surface. In some embodiments, the side support facilitates that the cleaning robot 162 can maintain its position longitudinally and / or maintain its orientation while traversing laterally across the surface of a panel.

[0135] In some embodiments, the articulated connection 160 may connect the side support 158 to a cart, such as a driving cart, of the cleaning robot 162. The articulated connection provides a degree of freedom that enables the side support to adjust its position relative to the cart, thereby reducing the likelihood of tilting or deviation from the intended path. Alternatively or additionally, the articulated connection 160 may connect the side support 158 to a cleaning unit of the robot.

[0136] For example, the side support 158 may include side wheels mounted on opposite sides of a fulcrum of a rocker beam. For example, the articulated connection may include a hinge that serves as the fulcrum of the rocker beam. The articulated connection 160 optionally attaches between the rocker beam and the cleaning unit. In some embodiments, (e.g., when the side support is on an upper cart and / or upper side of the panel) the side support 158 is configured to support at least partially a component of the weight of the cleaning unit parallel to the face of the panel. For example, the side support 158 may support at least partially the component of the weight of the machine parallel to the face of the panel.

[0137] In some embodiments, the articulated connection 160 may be a revolute joint, allowing rotation of the side support 158 with respect to the cleaning unit within the plane of the face of the panel. For example, the side wheels of the side support 158 may be equipped with a rotational hinge that allows them to climb steps and obstacles with reduced deviation of the robot from its path. The side wheels can rotate about the hinge to open an angle with respect to the solar panel, slightly lifting the driving cart while the robot continues forward. This mechanism helps to overcome the weight component and torque developed by the obstacle, ensuring smooth and continuous movement.

[0138] In some embodiments, the side support 158 may include an elastic mechanism that provides a restoring force to pull the cleaning robot 162 back to its preferred orientation. This feature is particularly useful when the robot encounters drag forces or other factors that cause deviation from its intended path. For example, spring-loaded side wheels can help to realign the robot and / or maintain efficiency and / or effectiveness.

[0139] Fig. 11 is a block diagram illustrating an exemplary robot cleaning system, in accordance with an embodiment of the current invention of the current invention. For example, in system 164, module 172 may be connected to carts 168, 182. Optionally, driving cart 168 may be powered by the passage of water. Optionally, the module 172 may be a rigid unit including a one or more cleaning units 176 and / or middle carts 174. Module 172 may include a middle cart 174 which may be a driven middle cart and / or a non-driven middle cart. For example, a non-driven middle cart may include one or more neutral wheels with a steering rotation axis and / or a directional stability system. Optionally, each cleaning unit 176 may include a brush and a link rod (brush shaft 180).

[0140] Driving cart 168 may include side supports 166. Passage of the side supports 166 over an obstacle and / or step may tilt the entire robot and / or divert the robot from its path. The obstacle may be a misalignment between adjacent solar panels and / or an object, etc. A degree of freedom may be added to the side supports 166 (e.g., a rotation axis). A degree of freedom may be added to the side supports 166 to allow the side supports 166 to climb a step and / or obstacle without deviating the robot from its path. Side supports 166 may rotate about rotation axis to open an angle with respect to the solar panel to slightly lift the driving cart 168 while the robot continues forward in the direction of movement. Side supports 166 climbing the obstacle and / or step may overcome a component of the robot's weight W sin a and / or the torque developed by this component against the deviation. Side supports 166 open an angle by rotation about the rotation axis, slightly lifting the driving cart, against the weight component W sin a, whereby the rotation about the rotation axis facilitates moving the robot forward in the direction of movement (X axis). Optionally, the robot may be powered by a water motor 170.

[0141] In some embodiments, robot may include a secondary cart 182. Optionally, secondary cart may be an end cart (e.g., a bottom cart) of the cleaning machine. Alternatively or additionally, secondary cart 182 may be unpowered. When secondary cart 182 on one side of solar panel lags relative to driving cart 168 on the other side of solar panel for some reason, a rotational axis of side supports 166 may open an angle between driving cart 168 and the side of the solar panel, thereby facilitating the continuous straight movement of the robot along the solar panel.

[0142] The rate of forward movement rate of the carts (driving cart 168 and secondary cart 182) may not always the same, even when the robot is moving in a straight line without any obstacles, and even though the carts are driven simultaneously via the brush shaft 180 of module 172. Optionally, the difference in the rate of forward movement may be due to slip and / or drag forces acting on the driving cart 168 which pulls a pressurized water supply hose (not shown). Optionally, the hose may be full of water at working pressure, which may exert a force, a drag. Optionally, the drag force may range between about 5 kg to about 10 kg, and / or about 10 kg to about 15 kg, and / or about 15 kg to about 30 kg. A deviation angle p may develop since the secondary cart 180 may move faster than the driving cart 168 pulling the water supply hose. The system may optionally include elastic side supports 184 (e.g., spring loaded wheels). The elastic side supports 184 may include a spring biased towards the solar panel configured to provide a restoring moment, in the direction opposite to the deviation angle p. Additionally, or alternatively, the weight component in the plane of the solar panels (W sin a) may provide a restoring moment in the direction opposite to the deviation angle p. Fig. 12 is a flow chart illustrating a method of use of an exemplary system, in accordance with an embodiment of the current invention of the current invention. For example, in method 186, the driving cart may move 188 the cleaning robot across the surface of the solar panels. The driving cart may be powered by the passage of water. The rotational axis of the side wheels may provide a degree of freedom between the cart and the solar panel. Rotational axis may open 190 an angle between the cart and the solar panel. The robot may continue 192 straight with reduced deviation from the direction of movement.

[0143] These embodiments are provided by way of example and are in no means intended to limit the scope of the invention.

[0144] While the invention has been described in its preferred form or embodiment with some degree of particularity, it is understood that this description has been given only by way of example and that numerous changes in the details of construction, fabrication, and use, including the combination and arrangement of parts, may be made without departing from the spirit and scope of the invention.

[0145] GENERAL

[0146] It is expected that during the life of a patent maturing from this application many relevant building technologies, artificial intelligence methodologies, computer user interfaces, image capture devices will be developed and the scope of the terms for design elements, analysis routines, user devices is intended to include all such new technologies a priori.

[0147] Unless otherwise defined, all technical and / or scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the invention pertains. Although methods and materials similar or equivalent to those described herein may be used in the practice or testing of embodiments of the invention, exemplary methods and / or materials are described below. In case of conflict, the patent specification, including definitions, will control. In addition, the materials, methods, and examples are illustrative only and are not intended to be necessarily limiting.

[0148] As used herein the term "about" refers to ± 10%

[0149] The terms "comprises", "comprising", "includes", "including" having" and their conjugates mean "including but not limited to".

[0150] The term "consisting of means "including and limited to".

[0151] The term "consisting essentially of means that the composition, method or structure may include additional ingredients, steps and / or parts, but only if the additional ingredients, steps and / or parts do not materially alter the basic and novel characteristics of the claimed composition, method or structure.

[0152] As used herein, the singular form "a", "an" and "the" include plural references unless the context clearly dictates otherwise.

[0153] As used herein, the term plurality may relate to 1, 2, 5, 10, 20, 50, 100, 500, or more.

[0154] Throughout this application, various embodiments of this invention may be presented in a range format. It should be understood that the description in range format is merely for convenience and brevity and should not be construed as an inflexible limitation on the scope of the invention. Accordingly, the description of a range should be considered to have specifically disclosed all the possible subranges as well as individual numerical values within that range. For example, description of a range such as from 1 to 6 should be considered to have specifically disclosed subranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6 etc., as well as individual numbers within that range, for example, 1, 2, 3, 4, 5, and 6. This applies regardless of the breadth of the range.

[0155] Whenever a numerical range is indicated herein, it is meant to include any cited numeral (fractional or integral) within the indicated range. The phrases "ranging / ranges between" a first indicate number and a second indicate number and "ranging / ranges from" a first indicate number "to" a second indicate number are used herein interchangeably and are meant to include the first and second indicated numbers and all the fractional and integral numerals therebetween.

[0156] It is appreciated that certain features of the invention, which are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the invention, which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable subcombination or as suitable in any other described embodiment of the invention. Certain features described in the context of various embodiments are not to be considered essential features of those embodiments, unless the embodiment is inoperative without those elements.

[0157] Although the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art. Accordingly, it is intended to embrace all such alternatives, modifications and variations that fall within the spirit and broad scope of the appended claims.

[0158] All publications, patents and patent applications mentioned in this specification are herein incorporated in their entirety by reference into the specification, to the same extent as if each individual publication, patent or patent application was specifically and individually indicated to be incorporated herein by reference. In addition, citation or identification of any reference in this application shall not be construed as an admission that such reference is available as prior art to the present invention. To the extent that section headings are used, they should not be construed as necessarily limiting.

Claims

CLAIMSWhat is claimed is:

1. A system for cleaning panels comprising: a cleaning unit; running gear maintaining said cleaning unit over a face of the panel; and an articulated joint connecting between the cleaning unit and the running gear.

2. The system of claim 1, wherein said panel includes a solar panel.

3. The system of claim 1, wherein said articulated joint allows rotation of the running gear with respect to the cleaning unit within a plane of the face of the panel.

4. The system of claim 3, wherein said articulated joint is a revolute joint.

5. The system of claim 1, wherein the running gear includes a support wheel resting on said face of said panel.

6. The system of claim 5, wherein said support wheel is a drive wheel of the system.

7. The system of claim 5, wherein said support wheel is a neutral wheel.

8. The system of claim 7, wherein said articulated joint includes a swivel caster.

9. The system of claim 8, wherein the swivel caster has a limited range of rotation.

10. The system of claim 1, wherein the running gear includes a side support configured to run along an edge of the panel for limiting longitudinal movement of the cleaning unit along the face of the panel.

11. The system of claim 10, side support includes two side wheels mounted on opposite sides of a rocker beam and wherein said articulated joint attaches between said rocker beam and said cleaning unit.

12. The system of claim 11, wherein the running gear includes a top carriage and the side wheels are positioned to roll laterally along a top edge of the panel.

13. The system of claim 12, wherein the side support is configured to support at least partially a component of weight of the cleaning unit parallel to the face of the panel.

14. The system of claim 13, further including a top carriage and wherein said top carriage includes said side support and a normal support panel supporting at least partially a component of a weight of the cleaning assembly perpendicular to the face of the panel.

15. The system of claim 14, wherein the normal support includes at least one of a wheel and a continuous track resting on said face of said panel.

16. The system of claim 1, wherein said running gear includes a normal support and a side support and said articulated joint connects between said normal support and said side support.

17. The system of claim 16, wherein said normal support is rigidly connected to said cleaning unit.

18. A system for cleaning panels comprising: a cleaning robot configured clean a panel, wherein the robot includes: an upper driving cart powered by a water motor; a lower secondary cart attached to the lower edge of the panel a brush unit connected to the driving cart and the secondary cart via a brush shaft; and at least two side wheels with a rotational axis, wherein the side wheels are attached to the drive cart and are configured to maintain the robot in a position relative to panel, and wherein the rotational axis is configured to facilitate the robot climbing a step or obstacle without deviating its path.

19. The system according to claim 18, wherein the side wheels are mounted to a side wheel arm.

20. The system according to claim 19, wherein the side wheel arm includes the rotational axis.

21. The system according to claim 19, wherein the rotational axis is connected to the driving cart by a bracket.

22. The system according to claim 18, wherein the brush unit is rigid.

23. The system according to claim 18, wherein the brush unit includes one or more brush modules and one or more middle carts.

24. The system according to claim 23, wherein middle cart is a driven middle cart or a nondriven middle cart.

25. The system according to claim 24, wherein the non-driven middle cart includes one or more neutral wheels with a steering rotation axis and a directional stability system.

26. The system according to claim 18, wherein the brush unit is connected to the driving cart and the secondary cart by an axial connection.

27. The system according to claim 18, wherein the secondary cart includes spring loaded side wheels.

28. A method for cleaning panels, the method comprising: retaining a cleaning machine over a panel with running gear; moving a cleaning machine in a preferred direction across a surface of a panel; adjusting an orientation between the running gear and a cleaning unit of the cleaning unit in response to a hinderance to said moving.

29. The method of claim 28, wherein said panel includes a solar panel and wherein said cleaning includes increasing an efficiency of said solar panel.

30. The method of claim 28, wherein said hinderance includes a misalignment of a said cleaning unit with said preferred direction of movement.

31. The method of claim 28, wherein said hinderance includes an obstacle in a path of said moving.

32. The method of claim 28, wherein said hinderance includes a misalignment of said panel.

33. The method of claim 28, wherein adjusting includes rotation of the running gear with respect to the cleaning unit within a plane of a face of the panel.

34. The method of claim 33, wherein said rotation is in a plane of a face of the panel.

35. The method of claim 28, wherein the running gear includes a support wheel resting on a face of said panel, the method further comprising support a portion of a weight of said cleaning machine normal to a face of said panel.

36. The method of claim 35, wherein said support wheel is a neutral wheel.

37. The method of claim 36, wherein said adjusting is via a swivel caster.

38. The method of claim 28, further including driving said moving with said running gear.

39. The method of claim 38, wherein said running gear includes a support wheel and wherein said driving is of said support wheel.

40. The method of claim 38, powering said driving with a pressurized water.

41. The method of claim 40, wherein a source of said pressurized water includes a supply hose and wherein said hinderance includes drag of said supply hose against said moving.

42. The method of claim 28, wherein said running gear includes a side support configured to run along an edge of the panel and wherein said retaining includes limiting longitudinal movement of the cleaning unit along a face of the panel via said side support.

43. The method of claim 42, further including a top carriage and wherein said top carriage includes said side support and a normal support, the method further including supporting at least partially a component of a weight of the cleaning assembly perpendicular to a face of the panel with said normal support.

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