DESC:FIELD OF INVENTION
[0001] The invention generally relates to solar panel cleaning robot. In particular, the present technique relates to system and method for integrated on-demand cleaning of photovoltaic (PV) panels.
BACKGROUND
[0002] Solar power is one of the most widely available sources of non-conventional energy across the globe. Solar panels also called photovoltaic (PV) panels, are used to generate solar power. The output delivered from these solar panels depends on the amount of irradiance, which reaches the solar cells. Many factors determine the optimum yield in the solar panel, the hardest to control being the environment. The environment contributes to soiling which causes large reductions in solar panel efficiency and power production. The soiling is commonly caused by snow, dust, salt, bird dropping, and rain. Hence, it is essential to clean the solar panels regularly. Large solar panel facilities are often located in remote desert areas, with conditions that are too hot and presently it is a labor intensive cleaning operations and monotonous in nature. The soiling threatens the productivity of the solar panels and requires scheduled cleaning. Hence the cleaning of the solar panel is challenging as it is predominately done in field and under sun. The present labor intensive cleaning process is inefficient, expensive and consumes higher efforts.
[0003] The prior art discloses various methods of cleaning the solar panels, the manual cleaning with water and wiping is the most effective way of cleaning, however the bird and bee droppings still remained on the panel. Initial dry cleaning for the entire solar panel followed by spraying water and wiping gave the best results. To achieve the best quality of cleaning there is a need to remove the top layer of dirt along the length of the solar panel arrays, perform selective wet cleaning to achieve high quality cleaning and wet cleaning to easily clean tough spots. The cleaning systems available in market do not provide all the required features with optimum use of resources like power and water. Hence there is a need to overcome the above drawbacks and to develop a solar panel cleaning system with advanced features.
[0004] Hence, there is a need of a method, system and computer program product which can overcome the above mentioned problems.
SUMMARY
[0005] Embodiments of the present invention provides a method and system for on-demand cleaning of solar panels. The method comprising sending an input commands for cleaning the solar panel by a user interface, receiving the input commands by a controller on the solar panel cleaning robot, capturing images by a vision module after dry cleaning and identifying if wet cleaning is required to be initiated, processing the images by a spot detection unit to identify one or more spot location on the solar panel for selective cleaning, identifying by an encoder co-ordinates of the one or more spots for wet cleaning and storing in a database, moving the solar panel cleaning robot to one or more spot location detected by vision system for wet cleaning by a programmable logic controller (PLC) and monitoring health of the robot by extracting data from a cloud server and displaying in a health dashboard.
[0006] The system for on-demand cleaning of solar panel according to an embodiment comprising a modular frame with supporting wheels for mounting the solar panel cleaning robot. A dry cleaning unit coupled to traction motor and supported with wheels for cleaning accumulated dust particle. A wet cleaning unit with wiper roller for on demand cleaning of solar panels. The integrated dry and wet cleaning unit moves in three dimension. A vision module for capturing images of the solar panel. A user interface for remotely connecting with solar panel cleaning robot and monitoring heath of the robot.
[0007] A control unit, comprises a controller, for processing the images to identify the dirt spots location for selective cleaning of the solar panel in a solar panel array on-demand basis. An encoder to identify the co-ordinates of the dirt spots for wet cleaning and a programmable logic controller (PLC) for receiving the detected spots locations form the controller and moving the solar panel cleaning robot to the dirt spot location for selective cleaning of solar panel after dry cleaning.
[0008] The method and system of the present invention provides both wet and dry cleaning options with fast and efficient dry cleaning along the span of the solar panel array. The complete system with detachable cleaning head is provided to navigate on the entire solar panel arrays providing a thorough clean of the solar panel. An adjustable wet cleaning head is provided to optimize the load on solar panels. According to an embodiment, an advanced user interface is provided which allows the user to communicate with run diagnostics and monitor the health of the solar panel cleaning systems. It allows large solar farms to remotely monitor the status of the solar panel cleaning systems as well as efficient operation of the system for rooftop solar farm users who are currently not being able to easily access their solar panels to check the health. The integrated dry and wet cleaning head utilizes optimal amount of water to deliver an effective cleaning with a solar powered battery. The integrated smart cleaning system offers an economical and high quality solution. The system offers optimum cleaning options based on the demand and extent of soiling with vision based wet cleaning optimizing water usage and requiring minimal maintenance.
[0009] The method, the system, and/or the apparatus computer readable storage medium disclosed herein may be implemented in any means for achieving various aspects, and may be executed in a form of a machine-readable medium embodying a set of instructions that, when executed by a machine, cause the machine to perform any of the operations disclosed herein. Other features will be apparent from the accompanying drawings and from the detailed description that follows.
BRIEF DESCRIPTION OF THE FIGURES
[0010] Example embodiments are illustrated by way of example and not limitation in the figures of the accompanying drawings, in which like references indicate similar elements and in which:
[0011] Figure 1 shows a system for on-demand cleaning of solar panels, according to an embodiment of the invention.
[0012] Figure 2a and 2b shows a schematic view of a replaceable brush arrangement for dry cleaning based on the solar panel type, according to embodiment of the present invention.
[0013] Figure 3a and 3b shows a schematic view of a replaceable brush arrangement for wet cleaning, according to an embodiment of the invention.
[0014] Figure 4a, 4b, 4c shows a schematic view of the system movement in X and Y direction and wet cleaning brush movement in Z direction to achieve precise cleaning at point of interest, according to an embodiment of the present invention.
[0015] Figure 5 shows a schematic view of the system with modular spring loaded replaceable wheel assembly based on location and environment, according to an embodiment of the present invention.
[0016] Figure 6a and 6b shows a schematic view of modular frame structure with cross member designed to reduce overall structural deformation, according to embodiment of the present invention.
[0017] Figure 7 shows a schematic view of a docking station for end-end cleaning the solar panel arrays, according to an embodiment of the present invention.
[0018] Figure 8 shows a schematic view of a dual cellulose sponge wiper roller for removing the dirt after the water based scrubbing process, according to an embodiment of the present invention.
[0019] Figure 9 shows a schematic view of the integrated dry and wet cleaning system with advanced vision and deep learning based artificial intelligence to identify location of the dirt on solar panels, according to an embodiment of the present invention.
[0020] Figure 10 shows a schematic view of the wet cleaning unit with in-built controller to spray water and scrub the solar panel on-demand, according to an embodiment of the present invention.
[0021] Figure 11 shows a block diagram of a smart system with cloud data connectivity, electrical and control system for wet cleaning and predictive health management according to an embodiment of the present invention.
[0022] Figure 12 shows a schematic diagram illustrating various components for on-demand cleaning of solar panels, according to an embodiment of the invention.
[0023] Figure 13 shows a flowchart illustrating a method for integrated dry and wet cleaning of photovoltaic (PV) panel’s on-demand basis, according to an embodiment of the invention.
[0024] Figure 14 shows a flowchart illustrating a method for spot detection for cleaning of photovoltaic panel, according to embodiment of the invention.
[0025] Figure 15 shows a schematic diagram illustrating a health dashboard, according to an embodiment of the invention.
[0026] Other features of the present embodiments will be apparent from the accompanying drawings and from the detailed description that follows.
DETAILED DESCRIPTION
[0027] Embodiments of the present invention provide a system and method for integrated on-demand cleaning of solar panels. The system of the present invention provides both dry and wet cleaning options with fast and efficient cleaning along the span of the solar panel array.
[0028] According to an embodiment, an advanced user interface is provided which allows the user to communicate with run diagnostics and monitor the health of the solar panel cleaning systems. It allows large solar farms to remotely monitor the status of the solar panel systems as well as efficient operation of the system for rooftop solar farm users who are currently not being able to easily access their solar panels to check the health. The invention provides a smart cleaning systems, vision based cleaning patterns and Internet of Things (IOT) data analytics.
[0029] The system and method of the present invention may be used in the dry, arid climates that require frequent cleanings and dusty climates that suffer more from stubborn soiling like bird dropping rather than having to combat frequent dust storms. The integrated dry and wet cleaning head utilizes optimal amount of water to deliver an effective cleaning with a solar powered battery. The integrated smart cleaning system offers an economical and high quality solution. It offers optimum cleaning options based on the demand and extent of soiling with vision based wet cleaning optimizing water usage and requiring minimal maintenance.
[0030] Figure 1 shows a solar panel cleaning system or robot 100 for on-demand cleaning of solar panels 704, according to an embodiment of the invention. The system 100 comprises a dry cleaning unit 102, a wet cleaning unit 104, a control unit 106, traction wheels 112, supporting wheels 114a, 114b, 114c and 114d, traction motor 110, vision module 108 and a battery 116. The system 100 is designed to move on the solar panel frame 704 in longitudinal direction (X-Axis) on the rows of solar panel 704. The dry cleaning is done in the longitudinal direction and wet cleaning unit 104 moves in vertical direction (Y-Axis). The wet cleaning head is armed and dis-armed by actuator 402 (Z-Axis). The system 100 is programmable to position itself at any point on the solar panel 704 array using X and Y axis control.
[0031] The dry cleaning unit 102 comprises a dry brush 103 with helical bristle arrangement for self-cleaning of accumulated dust particle. The dry cleaning unit 102 has an inner core 201 made of nylon and an aluminum shaft coupled with pin1 202 and pin2 204 running through the brush core, the shaft is coupled to the brush motor 110 using couplers 208 at both the ends. Traction wheels or driving wheels 112 on both ends are driven by a single shaft which is coupled to the traction motor 110. Speed of the traction motor 110 is equal to the dry cleaning rate. The wet cleaning unit 104 according to an embodiment comprises a timing belt pulley 122 driven by a motor 110 and a timer belt for its lateral movement (Y Axis). The wet cleaning unit 104 is guided with nylon supporting wheels 404 at corners. The wet cleaning head is armed and dis-armed with a motorized actuator 402 (Z-Axis) to optimize the pressure exerted by the circular wet cleaning brush 302 on to the solar panel 704. The wet cleaning head movement is controlled in Z axis to exert optimal pressure based on the type of solar panel 704 array.
[0032] According to an embodiment, the main drive control unit 106 is mounted on top of modular solar panel frame 118. The system 100 gets power from the battery 116 to protect the system 100 from any internal failure due to short circuit before it reaches to the main drive. The battery 116 power system enables the movement of motorized traction wheels 112 of the motor 110. When a traction motor 110 starts rotating, the traction wheels 112 gets momentum and moves the system 100 in forward direction. When system 100 moves forward, the dry brush motor 110 starts to spin at desired high speed to remove the dust particles from solar panel 704. The excess soiling on the solar panel 704 is removed by wet cleaning unit 104 through light scrubbing and will be wiped away by the wipers 306a and 306b attached to the wet cleaning unit 104. The main drive comprises a forward/reverse (FWD/REV) limit switches to stop the system 100 operation upon reaching the end limits of the traction or solar panel assembly end frames.
[0033] The wet cleaning unit 104 is integrated with the solar panel cleaning system 100, according to embodiment of invention. The wet cleaning motor drives the wet cleaning unit 104 vertically along the solar panel 704. The wet brush motor within the system operates the disk brush to remove tough soiling. The wet cleaning drive includes the FWD/REV limit switches to identify and stop the wet cleaning unit 104 operation when the end limits of the traction is reached. The vision module 108 is an on demand unit of the solar panel cleaning robot 100, it continuously captures images of the cleaned solar panel 702. These images are passed through pipeline, which performs pre-processing, followed by spot detection and identification. The final identified spots are then passed to control unit 106 for wet-cleaning.
[0034] Figure 2a and 2b shows a replaceable brush arrangement for dry cleaning based on the solar panel type, according to embodiment of the present invention. As shown in figure 2, the dry Brush 103 includes helical bristle arrangement for self-cleaning of accumulated dust particles. The dry brush 103 includes an inner core 201 member with provision for Pin1 202 and another Pin2 204 mounted on the motor 110. Both the Pin1 202 and Pin2 204 are engaged with aluminum key way 206 and coupled with coupler 208 for assembling and disassembling during brush replacement. Both the ends of the brush have same arrangement for coupling.
[0035] Figure 3a and 3b shows a replaceable brush arrangement for wet cleaning, according to an embodiment of the invention. The wet cleaning circular brush 302 is mounted on the shaft of the motor and is fastened by grub screw 304. The grub screws 304 enables user to replace the wet brush easily without removing the entire system, based on the solar panel type. The excess soiling on the solar panel 704 will be removed by the wet cleaning unit 104 through light scrubbing and will be wiped away by the wipers 306a, 306b attached to the wet cleaning unit 104.
[0036] Figure 4a, 4b, and 4c shows system 100 movement in X and Y direction and brush movement in Z direction to achieve precise cleaning at point of interest, according to embodiment of the present invention. As shown in figure 4, the solar panel 704 cleaning system is designed to move in a longitudinal direction (X Axis) on the rows of the solar panel and the wet cleaning unit 104 moves in lateral direction (Y Axis). The wet cleaning head is be provided with actuators 402 (Figure 4c) for movement in vertical direction (Z Axis). The system 100 is programmed to control the movement at any point on the array of the solar panels 704 using X and Y axis. The system is programmed to control the movement of wet brush in Z direction to exert optimal pressure on the solar panel array. The wet cleaning head is armed and dis-armed with a motorized actuator 402 (Z Axis).
[0037] Figure 5 shows the system 100 with easily replaceable supporting wheels 114a, 114b, 114c, 114d based on location and environment, according to an embodiment of the present invention. Figure 5b shows an adjustable wheel mounting support, with at least one nylon wheel rolling over the solar panel edge and are easily replaceable based on the location and environment. At least one nylon wheel rolling over the solar panel bottom support and are replaceable based on the location and environment. The supporting wheels 114a, 114b, 114c, 114d rolls on the top and side of the solar panel 704. The supporting wheels 114a, 114b, 114c, 114d are mounted on the solar panel frame with T-nut 502 and screw 504 assembly. The supporting wheels 114a, 114b, 114c, 114d can be adjustable through the length by loosening the screw 504, as shown in the figure 5.
[0038] Figure 6a and 6b shows a modular frame structure 118 with cross member designed to reduce the overall structural deformation, according to embodiment of the present invention. The cross member includes a modular aluminum extrusion profile 602 at all the corners with internal stiffener and external braces to reduce structural deformation of the longitudinal members, it is cost effective and ease to assemble.
[0039] Figure 7 shows a docking station 702 provided for end to end cleaning of the solar panels 704. A dry brush cleaning rod is provided for self-cleaning of dry brush 103, it ensures that the brush is cleaned on every run. The dock station 702 includes a charging unit 700, whenever the battery 116 drains, the system 100 moves towards the docking station 702 and auto plugged to charging unit 700.
[0040] Figure 8 shows a dual cellulose sponge wiper roller 306a and 306b for removing the dirt post the water based scrubbing process by circular brush 302, according to an embodiment of the present invention. The dual cellulose sponge wiper rollers 306a and 306b are mounted at the rear and front end of the system for wiping after the wet cleaning. The dual cellulose sponge wiper roller 306a and 306b are also water absorbent and absorbs excess water after the scrubbing operation.
[0041] Figure 9 shows an advanced vision and deep learning based artificial intelligence system to identify location of the dirt on solar panels, according to an embodiment of the present invention. As shown in figure, the vision module 108 is embedded on the system 100. The vision module 108 comprises at least one vision camera (refer figure.12 1216a and 1216b) and at least one IR array sensor (figure.12 1218a and 1218b). The fusion sensors are located at equidistant location to scan the solar panel 704 while performing the dry cleaning cycle. The system 100 will identify appropriate cleaning pattern, with the help of vision module 108. The system 100 further connects with internet of things (IOT) devices for providing comprehensive data analytics on the performance of identified systems. The system 100 is further integrated with network protocols for building management systems for data analytics and monitoring.
[0042] Figure 10 shows an integrated dry and wet cleaning system 100 with in-built controller unit 110 to spray water and scrub the solar panel 704 on demand, according to an embodiment of the present invention. The data collected from the fusion sensors 1218a, 1218b are analyzed by a single board computer 1206 to identify the dirt spots, which required regressive wet cleaning. The dirt spot location will be registered in the local memory of the computer in the form of X and Y coordinates. On demand, the complete system 100 traverse to the specific location, activate the wet cleaning unit 104, open the nozzle 1002 and jet spray 1004 the water for efficient cleaning with less resource utilization.
[0043] Figure 11 shows a smart system with cloud data connectivity 1124, according to an embodiment of the present invention. The single board computer 1206 on the system is connected with cloud data connectivity 1124 using onboard GSM modem network 1120 to enable remote connectivity, remote control and data logging. It enables to integrate the system with energy management system to estimate and improve operational efficiency of the solar plant. The predictive health management system data will enable the optimization of system utilization and perform maintenance management with lesser failure cases.
[0044] An electrical and control system for solar panel cleaning system, is as shown in Figure 11. The main drive control system 1112 of the present invention comprises a system 100 mounted on top of the solar panel 704 array with integrated battery 116 power system. The system 100 gets power from the battery 116 which utilizes a fuse 1104 and a breaker 1106 to protect the system 100 from any internal failure due to short circuit before it reaches to the main drive 1108. The battery power system 116 enables the movement of motorized traction wheels 112 of the motor and drive system. The strobe light indicates the operation of the system. When a traction motor 110 starts rotating, the traction wheels 112 gets momentum and moves the system in forward direction. When system moves forward, the dry brush motor 1114 starts to spin at desired high speed, which removes the dust particles from solar panel. The excess soiling on the panel is removed by wet cleaning unit 104 and wiped by the wipers 306a and 306b attached at the back end of the system 100. The main drive PLC 1108 comprises a FWD/REV limit switches 1116, which is enabled to stop the system 100 operation upon reaching the end limits of the traction or solar panel assembly end frames.
[0045] The wet cleaning unit 104 is integrated with the solar panel cleaning system 100 to protect from any internal failure due to short circuit. The power system enables the wet cleaning motor, the wet brush motor 1112 and the PLC main drive systems 1108. When the system 100 initiates its operation, the wet cleaning motor drives the wet cleaning unit 104 vertically along the panel. The wet brush motor 1112 within the system operates the disk brush which is used to remove tough soiling. The wet cleaning drive also has FWD/REV limit switches 1116 to identify and stop the wet cleaning system operation when the end limits of the traction have been reached.
[0046] Figure 12 shows a schematic diagram illustrating method for integrated dry and wet cleaning for on-demand cleaning of solar panels, according to an embodiment of the invention. The on-demand cleaning of solar panels comprises various modules such as user interface 1202, commands 1204, single board computer (SBC) 1206, controller 1208, database 1224, vision module 108a and 108b, spot detection module 1210, sensors 1218a and 1218b, a programmable logic controller (PLC) 1222, an encoder 1220, battery module 1212, cloud server 1504 and a health dashboard 1610.
[0047] The user interface 1202 is a web based application which works on a local network, where user can select the robot ID and the solar panel ID in the interface before starting the cleaning cycle. Once user inputs commands 1204 from the user interface 1202 to the solar panel cleaning robot 100 a signal is sent to the single board computer (SBC) 1206 over the network in the form of JavaScript Object Notation (JSON). The commands 1204 are send to controller 1208 through network using MQTT protocol 1207.
[0048] The user is provided with an option to toggle between on or off for the wet cleaning through user interface 1202. Once the dry cleaning operation is completed by the solar panel cleaning robot 100 the user get an images of the spots detected by the vision module 108a and 108b. At this point user has control to mark the spots that need wet cleaning or the user can simply command the robot to go back to the dock-station 702 without cleaning any spots that need wet cleaning.
[0049] The user interface 1202 is provided with features such as running cleaning cycle, either dry only or both dry and wet, scheduling cleaning cycle, either dry only or both dry and wet, confirming spots which needs cleaning after viewing actual spots images, reject spots for cleaning if required, cancelling cleaning cycle at any stage, viewing status of robot in a cycle, check battery 116 status and check history of previous cycles.
[0050] According to an embodiment, the SBC 1206 on solar panel robot includes controller 1208, spot detection module 1210, battery module 1212 and health module 1502. The controller 1208 interacts with other sub-systems in the solar panel cleaning robot and give required command to PLC 1222. All communications are done through MQTT protocol 1207. The controller 1208 receives commands 1204 from user interface 1202 which are processed and calls subsequent sub-systems, sends and receives data from spot detection module 1210 to identify the dirt spots for cleaning the solar panels, reads information from battery module 1212 and sends instructions to charge battery 116 if battery is low, and reads and writes information in to the database 1224. The battery module 1212 reads voltage and current data from battery 116 using analog to digital converter and converted to readable data. The health module 1502 reads status of all the modules in solar panel robot to monitor the health of the robot.
[0051] The controller 1208 in the SBC 1206 receives the javascript object notation (JSON) data from the user interface 1202 and checks whether the wet cleaning is required or not. If the wet cleaning is required then the wet cleaning unit 104 is initiated. If the wet cleaning cycle is not required, the SBC 1206 sends signal to the programmable logic controller (PLC) 1222 to start the motors for dry cleaning. Once the list of dirt spot location for the wet cleaning is identified, the PLC 1222 takes one spot at time after which it make the robot go to that location. Using the time based method a limited amount of water is sprayed followed by the brushing and wiping of the solar panel. The time measurement for these operation were done by performing these operation on multiple spots at different scenarios.
[0052] The dry cleaning is the default step that is done before vision module 108a and 108b data to work. The dry brush 103 of the robots are designed in a way that they efficiently clean the loose dust particle off the panels. The remaining spots on panels which are left after dry cleaning are considered for wet cleaning, the dirt spots are detected after processing the frame needs only wet cleaning. If the wet cleaning cycle is not required, the SBC 1206 sends signal to programmable logic controller (PLC) 1222 to start the motors 110. The motor 110 rotates till end point of the dry cleaning is reached. The endpoint is determined by the left proximity sensor placed on the robot. As soon as the dry cleaning cycle is completed the robot goes back to the docking station 702. The dry cleaning and vision capturing stops when the left proximity sensor get activated and the robot wait for the frames to process.
[0053] The wet cleaning is an on demand functionality that is followed by the dry cleaning. If the wet cleaning is required then the wet cleaning module is initiated. The vision module 108 captures the images and thermal data of the solar panel after the dry cleaning. The spot detection module 1210 receives data from vision module 108 to detect spots. The images are taken which are then processed using various techniques to detect dirt spots. Once dirt spots are detected, its co-ordinates (X, Y) are generated based on encoder data and stored in database 1224. A signal is sent to controller 1208 once it is completed for further execution.
[0054] Once the image data is received from vision module 108, the spot detection module 1210 separates the thermal image and red green blue (RGB) image and stores in a database 1224. Further the color of RGB image is changed to grayscale, user selects the region of interest on the processed image, normalize the image, identify binary threshold, and perform morphological operation to remove noise, set a threshold for the area and shape of the acceptable dirt spot. A blob detector is used to detect the coordinate of the spot and performs the scaling on the detected coordinates, so as to convert them into panel frame.
[0055] Iterate each detected coordinate, if the area of coordinate is greater than the threshold area, then calculate the center of the pixel, if the area of coordinate is not greater than the threshold area then discard and continue to detect the coordinate. Perform the scaling of the pixel using blob detector and store the information if the frame with its coordinates in the form of Json to the list of position that needs wet cleaning. solar panel cleaning robot first perform the dry cleaning using the brush and then go to the exact spot detected by the vision system by its advanced vision based technology, and then spray calculated amount of water followed by brushing and wiping it of the panel.
[0056] For every 600 mm the SBC 1206 triggers vision module 108 to capture image and send data. Whenever the data is received from the vision module 108 the SBC 1206 process the frame using advance computer vision techniques to detect dirt spots. After processing the data the system stores the location of the detected spots in a database 1224 and wait for the cycle to get completed. Once the dry cycle is completed the detected list of spots is send to the PLC 1222. The PLC 1222 makes the robot to go to those location one at a time and perform wet cleaning. As soon as all the spots are processed the robot goes back to the docking station 702. The information from the controller 1208, spot detection module 1210, battery module 1212 and health module 1502 are sent to cloud server 1504 on continuous time interval using MQTT protocol 1207.
[0057] According to an embodiment, the logs of all the operation that takes places while the cleaning is performed is stored in the database 1224 for later study and debugging. The database 1224 has schema to store the details of the cycle logs along with status, information collected from vision module 108, spot detected after processing of images, time for which the operation was performed , battery details and user inputs.
[0058] According to an embodiment, the encoder 1220 is a feedback sensor provides data for localizing the robot on the solar panel. The encoder 1220 is connected to the motor of the robot, as the motor rotates user gets the data from the encoder 1220 which helps in determining the location as well direction of the robot. When the dirt spot location is given to PLC 1222, PLC 1222 rotates the motor and takes feedback from the encoder 1220 till the time it reaches the desired location.
[0059] According to an embodiment a cloud server 1504 stores all the data sent by various robots in the network. This would act as single place for all the data which would later be used for creating dashboard.
[0060] According to an embodiment health dashboard is a web based application which extracts data from cloud server 1504 and display charts and other visualization. The charts may include robot status, robot usage, robot health and robot predictive health care. The robot status display current status, current position, user messages. The robot usage shows history of robot usage. The robot health 1506 visualizes health of robot such as component failure, battery 116 status, next recharge summary, water refill alert. The robot predicative health care data is provided based on the data history and provide alert to user for changing parts or battery.
[0061] As shown in the figure 12, the PLC 1222 controls all robot movements including horizontal and vertical movement, wet module cleaning, wiper system cleaning, control commands from radio frequency module and user interface 1202. It also controls dry brush actuation movement to ensure all time contact of dry brush 103 with solar panel 704 surface for efficient cleaning. The SBC 1206 module includes complete backend logic including communication with PLC 1222 using Modbus protocol and user interface 1202 using application programming interface (API). This can be implemented in both C++ programming language and python. The C++ is used for faster communication with PLC 1222 and python for rest of functionality. The vision data is collected from vision module 108 and processed data with spot position defined in X, Y is passed using MQTT protocol 1207. These points are then passed sequentially, closest point first, to robot for cleaning using water. Once cleaned wiper system 306a and 306b is activated for cleaning excess water from panel surface. All data collected from camera and thermal sensor are stored locally in Sqlite3 database 1224 in form of files. The data dump is later transferred to webserver over network for data analytics.
[0062] The webserver is the main module for user interaction and robot management. It is implemented in html, css, java script and boot strap for user friendly interaction. The web server module controls all operation of robot including on demand dry cleaning cycle, scheduled dry cleaning cycle, auto wet cleaning. It also displays real time status, robot battery 116 status and performance in form of dashboards. The user can easily schedule cleaning or start immediately. The cleaning can be scheduled in advance. Once process is started, user can view current status of robot under status tab which depicts completed, in progress and not started steps. The vision system is an on demand unit of solar panel cleaning robot, which continuously captures images of cleaned panel. These images are passed through pipeline, which performs pre-processing, followed by spot detection and identification. Final identified spots are then passed to controller 1208 for wet-cleaning processing.
[0063] Figure 13 shows a flowchart illustrating a method for integrated dry and wet cleaning of photovoltaic (PV) panel’s on-demand basis, according to an embodiment of the invention. During solar panel cleaning process, user inputs commands from the user interface (1304) to the solar panel robot to start the cleaning cycle (1302). Once user press the start button, a signal is sent to single board computer over the network in the form of JSON (1306). The SBC 1406 receives the JSON data and checks whether the wet cleaning is required or not (1308). If the wet cleaning is required then the wet cleaning module is initiated. For every 600 mm the SBC 1406 triggers vision module 108 to capture image and send data (1314). Whenever the data is received from the vision module 108 the SBC 1206 process the frame using advance computer vision techniques to detect spots (1316). After processing the data the system stores the location of the detected spots in a database 1224 and wait for the cycle to get completed (1318). Once the dry cycle is completed the detected list of dirt spots are send to the PLC (1320). The PLC 1222 makes the robot to go to those location one at a time and perform wet cleaning (1326). If dry cleaning cycle not completed (1322), capture data (1224) and check if the frame is available.
[0064] Once the list of location for the wet cleaning spot is given by the SBC 1206 to PLC 1222, PLC 1222 takes one spot at time after which it make the robot go to that location (1326). After which using the time based method limited amount of water is sprayed and then followed by the brushing and wiping of the panel (1328) and stop the cleaning (1330). The time measurement for these operation were done by performing these operation on multiple spots at different scenarios.
[0065] If the wet cleaning cycle is not required, the SBC 1206 sends signal to programmable logic controller (PLC) 1222 to start the motors (1310). The Motors rotates till end point of the dry cleaning is reached. The endpoint is determined by the left proximity sensor placed on the robot (1312). As soon as the dry cleaning cycle is completed the robot goes back to the docking station and stopped (1313).
[0066] Figure 14 shows a method for spot detection for cleaning of photovoltaic panel, according to embodiment of the invention. The spot detection module receive image data from the vision module (1404), once the image data is received, spot detection module separates the thermal image and RGB image (1406) and stores in a database (1408). Further the color of RGB image is changed to grayscale (1410), user selects the region of interest on the processed image (1412), normalize the image (1414), identify binary threshold (1416), and perform morphological operation to remove noise (1418), set a threshold for the area and shape of the acceptable dirt spot (1420). A blob detector is used to detect the coordinate of the spot and performs the scaling on the detected coordinates, so as to convert them into panel frame (1422).
[0067] Iterate each detected coordinate (1424), if the area of coordinate is greater than the threshold area, then calculate the center of the pixel (1430), if the area of coordinate is not greater than the threshold area then discard (1426) and continue to detect the coordinate (1428). Perform the scaling of the pixel using blob detector (1432) and store the information if the frame with its coordinates in the form of Json to the list of position that needs wet cleaning (1434) and stop the spot detection process (1436).
[0068] Figure 15 shows a schematic diagram illustrating the health dashboard 1510, according to an embodiment of the invention. The robot health data 1506 and robot data 1508 is sent to cloud from SBC 1206 through MQTT Protocol 1207. The data from battery module 1212 and health module 1502 in SBC 1206 is stored in the data base 1224 and is regularly updated to cloud server 1504. The health dashboard 1510 is a web based application which extracts data from cloud server 1504 and display charts and other visualization through Mqtt protocol 1207. The charts may include robot status, robot usage, robot health and robot predictive health care. The robot status display current status, current position, user messages. The robot usage shows history of robot usage. The robot health 1506 visualizes health of robot such as component failure, battery 116 status, next recharge summary, water refill alert. The robot predicative health care data is provided based on the data history and provide alert to user for changing parts or battery.
,CLAIMS:What is claimed is:
1. A method for on-demand cleaning of solar panels (704), comprising;
sending, by a user interface (1202), an input commands (1204) for cleaning the solar panels (704);
receiving the input commands (1204), by a controller (1208) on the solar panel cleaning robot (100); wherein the solar panel cleaning robot (100) comprises a dry cleaning unit (102) and a wet cleaning unit (104);
capturing images, by a vision module (108) after dry cleaning, to identify if wet cleaning is required to be initiated by the user interface (1202);
processing the images, by a spot detection module (1210), to identify one or more spot location on the solar panel (704) for selective cleaning;
identifying, by an encoder (1220), co-ordinates of the one or more spots for wet cleaning and storing in a database (1224);
initiating, by the solar panel cleaning robot (100), wet cleaning of the identified spot based on the co-ordinates.
2. The method according to claim 1, initiating the wet cleaning comprising moving, by a programmable logic controller (PLC) (1222), the solar panel cleaning robot (100) to one or more spot location detected by vision module (108) for wet cleaning.
3. The method according to claim 1 further comprising monitoring health, by controller (1208), the solar panel cleaning robot (100) by extracting data from a cloud server (1504) and displaying in a health dashboard (1510).
4. The method according to claim 1, wherein the user interface (1202) is a web based application, comprising:
selecting one or more robot identity (ID) and one or more solar panel ID for cleaning in the solar panel (704) array;
running and scheduling cleaning cycle, either only dry or both dry and wet cleaning;
identifying dirt spots for cleaning after viewing actual images captured from the vision module (108);
cancelling cleaning cycle at any stage,
viewing status of robot and its battery level, and
commanding the robot to go back to the dock-station (702) without cleaning any spots.
5. The method according to claim 1, wherein receiving the input commands (1204) from the user interface (1202) to the controller (1208) in a single board computer (SBC) (1206) over the network in the form of JavaScript Object Notation (JSON).
6. The method according to claim1, wherein the sending input commands (1204) over the communication network through a message queuing telemetry transport (MQTT) protocol (1207).
7. The method according to claim 1, wherein the vision module (108) comprises atleast one camera module (1216) for capturing images and atleast one sensor module (1218) for capturing thermal data from the solar panel.
8. The method according to claim 1, wherein the vision module (108) is activated only when wet cleaning is required during the cleaning cycle.
9. The method according to claim 1, wherein the controller (1208), comprising:
receiving the input commands (1204) from the user interface (1202);
receiving information captured from the vision module (108) and a spot detection module (1210) to identify dirt spots for cleaning of solar panels;
sending instructions to the programmable logic controller (PLC) (1222) to start motors for the dry cleaning, if the wet cleaning is not required;
monitoring a battery (116) status;
reading and writing information related to the battery status, health status, dirt spots, static information and results in to database (1224), and
reading voltage and current data from battery module (1212) using analog to digital converter and converting to readable data.
10. The method according to claim 1, wherein the PLC (1222), comprising:
receiving list of selected dirt spots for wet cleaning from SBC (1206);
sending instruction to move the solar panel cleaning robot (100) to go to the dirt spot location based on the encoder value;
controlling an actuator (402) for spraying limited amount of water on the identified dirt spot; and
brushing and wiping at multiple spots on the solar pane (704);
11. The method according to claim 1, wherein the method for dry cleaning, comprising:
sending input commands (1204) to the SBC from the user interface (1202) to initiate cleaning;
receiving the images from the spot detection module (1210) to identify dirt spots for cleaning of solar panels;
processing the images and identifying if the wet cleaning is required;
starting dry cleaning motor if wet cleaning is not required by sending signal from SBC (1206) to PLC (1222);
identifying the end point on the solar panel for the dry cleaning based on sensor data; and
moving robot to docking station (702) till further frames are processed.
12. The method according to claim 1, wherein the method for on-demand wet cleaning of solar panel, comprising:
sending input commands (1204) from the user interface (1202) to the SBC (1206);
initiating dry cleaning of solar panel from dry cleaning unit (102);
capturing the images and the thermal data from the vision module (108) after the dry cleaning;
processing the images and the thermal data by the spot detection module (1210) to detect the dirt spots;
identifying the co-ordinates of the dirt spots based on the encoder data,
storing the location of dirt spots in the database (1224),
sending the detected dirt spot location to the PLC (1222), and
moving the solar panel cleaning robot to the dirt spot detected by the vision module (108), and
spraying water followed by brushing and wiping of the solar panel (704).
13. The method according to claim 1, wherein the method for identifying dirt spot from spot detection module (1210), further comprising:
receiving the image data from the vision module (108);
separating the thermal image and Red Green Blue (RGB) image format and storing in the database (1224);
changing the color of the RGB image to grayscale;
selecting the region of interest on the processed image through the user interface (1202)s;
normalizing the image,
identifying binary threshold of the image,
performing morphological operation to remove noise,
setting a threshold for the area and shape of the acceptable dirt spot;
identifying atleast one coordinates of the dirt spot by a blob detector, and
scaling the detected coordinates to convert into panel frame (118).
14. The method according to claim 1, where in method for identifying the coordinate for wet cleaning, comprising:
identifying threshold for atleast one coordinate on the solar panel (704);
calculating if center of pixel area is greater than threshold;
discarding if the pixel area is less than threshold, and
storing the details of the frame with its coordinates in the form of Json if the pixel area is greater than threshold for wet cleaning.
15. The method according to claim 1, wherein the encoder (1220) is a feedback sensor which provides data for localizing the robot on the solar panel, the encoder comprises:
coupling with motor of the solar panel cleaning system (100);
tracking the location and direction from the encoder (1220) as the motor rotates on the solar panel (704);
sending the location details to the PLC (1222), and
guiding the solar panel cleaning system (100) to move to the specific location on the solar panel.
16. The method according to claim 1, wherein displaying health of solar panel cleaning robot (100) in a health dashboard (1510) comprising:
displaying current status, current position, user messages, history of robot usage, health of component failure, battery status , next recharge summary, water refill alert, predicative health care based on history of data, alert to user for changing battery 116.
17. The method according to claim 1, wherein the information from the controller (1208), spot detection module (1210), battery module (1212) and health module (1502) are sent to cloud server (1504) on continuous time interval through MQTT protocol (1207).
18. The method according to claim 1, wherein the details captured in the database (1224) comprises;
storing cycle logs and status information;
extracting information from vision module (108), and
extracting data for the user interface (1202) operations.
19. A system for on-demand cleaning of solar panels (704), comprising;
a modular frame (118) with supporting wheels (114) for mounting the solar panel cleaning robot (100);
a dry cleaning unit (102) coupled to traction motor (110) and traction wheel (112) for cleaning accumulated dust particle;
a wet cleaning unit (104) with wiper roller (306a, 306b) for on demand cleaning of solar panels (704); wherein the integrated dry and wet cleaning unit (104) moves in three dimension.
a vision module (108) for capturing images of the solar panel (704);
a user interface (1202) for remotely connecting with solar panel cleaning robot (100) and monitoring heath of the robot (100);
a control unit (106), comprising:
a controller (1208), for processing the images to identify the dirt spots location for selective cleaning of the solar panel in a solar panel (704) array on-demand basis,
an encoder (1220), to identify the co-ordinates of the dirt spots for wet cleaning;
a programmable logic controller (PLC) (1222), receives the detected spots locations form the controller (1208) and moves the solar panel cleaning robot to the dirt spot location for selective cleaning of solar panel after dry cleaning.
20. The system according to claim 19, wherein a power system in the wet cleaning unit (104), comprises;
a wet cleaning motor for driving the wet cleaning unit (104) vertically along the solar panel (704);
a wet brush motor to operate a brush for removing tough soiling;
an forward reverse (FWD/REV) limit switches to identify and stop the wet cleaning unit (104) operation when the end limits of the traction wheels (112) are reached.
21. The system according to claim 19, wherein the dry brush (103) is replaceable.
22. The system according to claim 19, wherein the dry cleaning unit (102), comprises:
a dry brush (103) with helical bristle and an inner core (201);
a shaft running through the inner core (201);
the shaft connected with aluminum key (206) and coupled with the dry brush motor 110 at both the ends for assembling and disassembling during brush replacement; and
a traction wheels (112) connected at both ends of the dry brush (103) are driven by a single shaft (202) which is coupled to the traction motor (110);
23. The system according to claim 19, wherein the wet cleaning unit (104), comprises;
a circular brush (302) mounted on the motor shaft;
an actuator (402) coupled to motor shaft to exert optimal pressure in z-axis based on solar panel type;
Wherein the circular brush (302) is fastened with motor shaft using a grub screw (304) to replace the wet brush easily without removing the entire system.
24. The system according to claim 19, wherein the supporting wheel 114a, 114b, 114c, 114d is mounted on solar panel frame with T-nut (502) and screw (504) assembly.
25. The system according to claim 19, wherein the supporting wheels (114a, 114b, 114c, 114d) mounted on the solar panel are adjustable through the length by releasing the screw (504).
26. The system according to claim 19, wherein the modular frame structure (118) comprises an aluminum extrusion profile (602) at corners of the frame with internal stiffener and external braces to reduce structural deformation.
27. The system according to claim 19, wherein the docking station (702) includes a charging unit (700) for auto plugging and charging the solar panel cleaning robot whenever battery (116) drains.
28. The system according to claim 19, wherein the wet cleaning unit (104) comprises a dual cellulose sponge wiper roller (306a, 306b) for removing the dirt post the water based scrubbing process.
29. The system according to claim 19, wherein the vision module (108) comprises at least one vision camera (1216) and at least one infrared sensor (IR) array sensor (1218) to scan the solar panel during the dry cleaning cycle.
30. The system according to claim 19, wherein the single board computer (1206) on the solar panel robot is connected with cloud server (1504) using onboard Global System for Mobile Communications (GSM) modem network to enable remote connectivity, remote control and data logging.