FIELD OF THE INVENTION

[01] The present invention relates to a closed loop feedback control system for cleaning the solar panel by using programmable robotic system. Moreover, the present invention further relates to a method for controlling the robots movement based on its own rechargeable battery power and the present invention is operable by using mobile and/or laptop having WIFI facility.
BACKGROUND OF THE INVENTION
[02] Background description includes information that may be useful in understanding the present subject matter. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed subject matter, or that any publication specifically or implicitly referenced is prior art.
[03] As the background studies, solar parks are becoming more prevalent around the world and has an expected lifetime of 20 – 25 years. The maximum power generated by the solar panels during daytime depends on many factors such as shadow, snow, high temperatures, pollen, bird droppings, sea salt, dust and dirt but the main factor i.e. the accumulation of dust particles and debris on the surface of photovoltaic (PV) panels reduces the power output especially in arid, dusty environments. The accumulation of dust on the surface of the photovoltaic modules decreases the incoming irradiance to the cell and produces power losses.
[04] The common solution is to clean the modules with water, but in large-scale photovoltaic plants this task is often expensive, especially in those areas with water shortage. As a result of continuous soiling, a layer of dirt piles up on top of the glass of the solar panel reducing its transmittance and therefore decreasing the power output of the entire system. It is often difficult and dangerous to reach the solar panels and clean them manually with or without water.
[05] Moreover, to address another solution of the above discussed problem, mobile robots are used to clean the surface of the solar panel. Most mobile robots found in the prior art are limited to cleaning the surface of the solar panels with cleaning brushes and use an additional rails either

mounted on the side of the solar panel rows or along with the solar panel rows to be used as guide rails for the robot to travel. A few prior arts are discussed in below:
[06] The cited patent US 2013/0305474 A1 is titled as Solar Panel Cleaning System and Method, describes a system and method for cleaning rows of solar panels where each solar row has an upper edge elevated above ground level and a lower edge to provide an inclination of the solar row. Operation and movement of the cleaning assembly is controlled so as to clean a surface of the solar panels during downward movement. The cleaning assembly is preferably not operative during upward movement. During downward movement, the cleaning assembly removes dirt, debris and dust from the Surface of the solar panels and generates an air stream to blow off the dirt, debris, and dust. The system further includes a guide system for moving the cleaning assembly to align with successive solar panel rows.
[07] The cited patent EP 2048455A2 is titled automatic solar panel cleaning system, comprises of longitudinal rails, cleaning brushes, a drive unit mounted with possibility of linear displacement along the longitudinal rails and provided with at least one motor element for the rotational actuation of the cleaning brushes and the movement of said cleaning brushes, together with the drive unit, along the longitudinal rails, an electric control panel and a rain sensor for the automatic start-up of the drive unit. This system uses longitudinal rails for the robot to travel.
[08] In cited patent US 20170331418 A1 discloses about cleaning mechanism having water spray function and photovoltaic panel cleaning equipment having same. The cited prior art is claimed a cleaning mechanism having a water spray function, adapted for use on a photovoltaic panel, comprising: a cleaning rack, the cleaning rack comprising a first connecting rod, a second connecting rod, a third connecting rod and a fourth connecting rod which are detachably connected, to control rapidly move to a water tank at a water getting point, and the water suction device.
[09] In cited patent US 2011/0094549 A1 is titled as cleaning system for solar panel, a cleaning system for Solar panels includes a number of solar cells and a transparent protection pane covering the Solar cells. The cleaning device is affixed on the transparent protection panel. The operating device includes a motor, a pulley and a belt. The motor is affixed on one end of the first sidewall. The pulley is affixed on the other end of the first sidewall. The belt is wrapped around the rotating

shaft of the motor and the pulley. The cleaning device includes an axle connected to the operating device and a washer provided on the axle. The cleaning device is driven by the operating device to clean the Solar panel. This system uses a frame as guide for the robot to travel.
[010] Hence, there is a need of automated system and method for controlling the robots for cleaning the solar panels without water/chemical/other spay and can be operated remotely by using mobile/laptop having Wi-Fi connection.
OBJECTS OF THE INVENTION
[011] In view of the foregoing limitations inherent in the state of the art, some of the objects of the present disclosure, which at least one embodiment herein satisfy, are listed herein below.
[012] It is therefore, the primary object of the invention to propose a closed loop feedback control system for an automated and programmable robotic solar panel cleaning system.
[013] Another object of the proposed invention is to monitor the various parameters of the robot.
[014] Still another object of the proposed invention is that the mobile solar panel cleaning robot operates on its own power source i.e. rechargeable batteries which are charged by an independent solar panel.
[015] Yet another object of the proposed invention is that the mobile solar panel cleaning enables itself at parking station for charging the on-board rechargeable batteries.
[016] Still yet object of the proposed invention is that the mobile solar panel cleaning consumes minimum power while it is not in operation.
[017] Yet another object of the proposed invention is that the HMI (Human Machine Interface) for mobile solar panel cleaning robot can be any mobile or laptop having Wi-Fi facility.

[018] These and other objects and advantages of the present invention will be apparent to those skilled in the art after a consideration of the following detailed description taken in conjunction with the accompanying drawings in which a preferred form of the present invention is illustrated.
SUMMARY OF THE INVENTION
[019] One or more drawbacks of conventional systems for cleaning the solar panel array by controlling robots operation are overcome, and additional advantages are provided through the system in the present disclosure. Additional features and advantages are realized through the technicalities of the present disclosure. Other embodiments and aspects of the disclosure are described in detail herein and are considered to be part of the claimed disclosure.
[020] In the embodiments, the present invention is directed for an automated cleaning apparatus for solar panel, wherein solar panel consisting of parking station and cleaning system cleans the top surface of the solar panels. Moreover, the closed loop feedback control system is used for an automated and programmable robotic solar panel cleaning system, wherein a mobile robot can travel horizontally (X-direction) on the edges of solar panel frame, and during cleaning operation a cleaning device can travel vertically (Y-direction), for cleaning the accumulated dust on the top surface of solar panel, without use of any fluid such as water or without use of any chemical. Further, the mobile robot parks itself at a parking station after the cleaning of entire solar panel array consisting of plurality of solar panels
[021] In the one aspect of the present invention, the automated control system for an automated cleaning apparatus /system for solar panel, wherein solar panel consisting of parking station and cleaning system cleans the top surface of the solar panels, the control system comprising at least one battery charging unit to recharge at least two batteries and at least one power unit to provide power to said control system; at least a system unit to draw minimum current from battery during the cleaning system not in operation; at least a controller to control the speed of DC motor through DC motor drives, wherein controller consisting of at least one Digital Computer, that has multiple inputs and output, at least one transistor based I/O (input/output) module to provide PWM (Pulse Width Modulation) signal to control the motor speed and direction; a plurality of different kind of sensors for automatic ; at least one secured communication media; and at least one HMI (Human

Machine Interface) to monitor various parameters of cleaning system through a secured wireless connectivity wherein, various parameters of cleaning apparatus are like current, voltage, number of panels cleaned, present position of cleaning apparatus, motor conditions and others.
[022] In said aspect of the present invention, the automated control system may include the
following features:
(i) the cleaning apparatus is a mobile robotic solar panel cleaning device, characterized in that the
cleaning device may/can travel vertically (y-direction) for cleaning dust on the top surface of the
solar panel without using water or any other chemical and after cleaning action finished, the mobile
robot moves horizontally (x-direction) on top edges and the bottom edge of solar panel to the new
cleaning position and the cleaning cycle repeats,
(ii) the mobile robot parks itself at a parking station to power up the cleaning apparatus so that it
takes minimum amount of current,
(iii) solar panel array consists of a plurality of solar panels that incorporates a plurality of solar
rows, wherein the solar rows being substantially parallel to each other.
(iv) the power unit of the solar panel cleaning robot entails at least two on board 12V, 24AH sealed
lead acid rechargeable batteries,
(v) battery charging unit consists of 120wp, 19.95V (max) standalone solar panel mounted on
parking station, and charge controller for charging the on-board re-chargeable batteries (11,12)
through the stationery insulated charging contacts,
(vi) controller consists of Digital Computer configured with multiple inputs and outputs interface,
controlled by a simulated program stored in controller’s memory, a transistor based I/O
(input/output) module to provide PWM (Pulse Width Modulation) signal to control the motor
speeds and direction,
(vii) mobile solar panel cleaning robot incorporating a secured 2.4 GHz, IEEE 802.11 wireless
communication protocol, has been used for communication between the robot and HMI using a
router, wherein the WI-FI router is connected with Digital Computer through a network
connectivity.
(viii) HMI is either a portable communication device or personal computer, having the WIFI
connectivity, is used to control various parameters of solar panel cleaning robot like current,

voltage, number of panels cleaned, present position of the robot, motor conditions and other, and operates in two mode as manual or automatic.
[023]The preferred embodiment of the present invention is having other features and advantages which are disclosed in the appended dependent claims.
[024] Other objects, features, and advantages of the present disclosure will become apparent from the following detailed description. It should be understood, however, that the detailed description and the specific examples, while indicating specific embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.
[025] Various objects, features, aspects and advantages of the inventive subject matter will become more apparent from the following detailed description of preferred embodiments, along with the accompanying drawing figures in which like numerals represent like components.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
[026] The illustrated embodiments of the subject matter will be best understood by reference to the drawings, wherein like parts are designated by like numerals throughout. The following description is intended only by way of example, and simply illustrates certain selected embodiments of apparatus that are consistent with the subject matter as claimed herein, wherein:
[027] Figure-1 illustrates the mobile solar panel cleaning robot mounted on a solar panel and parking station.
[028] Figure-2 illustrates a controls block diagram for solar panel cleaning robot
[029] Figure-3 illustrates the flow diagram of the control system.
[030] Figure-4 illustrates the 360 degree rotating encoder.
[031] Figure-5 illustrates the wiring diagram of the control system.

[032] Figure-6 illustrates the battery parameters monitoring.
[033] Figure-7a and Figure 7b illustrate the front views of the HMI (Human Machine Interface) which can be operated by using communication media either a mobile phone/ tablet PC or a personal computer.
[034] Figure-8a and Figure-8b illustrate both the manual mode and automatic mode of operation in detailed as explained in the flow charts. These mode of operations are performed by using a user friendly HMI.
[035] The figures depict embodiments of the disclosure for purposes of illustration only. One skilled in the art will readily recognize from the following description that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles of the disclosure described herein.
DETAILED DESCRIPTION OF THE INVENTION
[036] The detailed description of various exemplary embodiments of the disclosure is described herein with reference to the accompanying drawings. It should be noted that the embodiments are described herein in such details as to clearly communicate the disclosure. However, the amount of details provided herein is not intended to limit the anticipated variations of embodiments; on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the present disclosure as defined by the appended claims.
[037] It is also to be understood that various arrangements may be devised that, although not explicitly described or shown herein, embody the principles of the present disclosure. Moreover, all statements herein reciting principles, aspects, and embodiments of the present disclosure, as well as specific examples, are intended to encompass equivalents thereof.
[038] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments. As used herein, the singular forms “a”, “an”, and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises”, “comprising”, “includes”, “consisting” and/or “including” when used herein, specify the presence of stated features, integers,

steps, operations, elements and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components and/or groups thereof.
[039] It should also be noted that in some alternative implementations, the functions/acts noted may occur out of the order noted in the figures. For example, two figures shown in succession may, in fact, be executed concurrently or may sometimes be executed in the reverse order, depending upon the functionality/acts involved.
[040] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which example embodiments belong. It will be further understood that terms, e.g., those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.
[041] The present invention relates to invention of a descent and precise closed loop feedback control system for an automated and programmable robotic solar panel cleaning system wherein a mobile robot that can that travel horizontally (X-direction) on the edges of solar panel frame, a cleaning device that can travel vertically (Y-direction), cleaning the accumulated dust on the top surface of solar panel, without use of any fluid such as water or without use of any chemical. Further, the mobile robot parks itself at a parking station after the cleaning of entire solar panel array consisting of plurality of solar panels
[042] One embodiment of the present invention, the mobile solar panel cleaning robot consists of a metallic or non-metallic frame 2 on which a bottom drive 4, a top drive 3, two right limit switches or proximity sensors 5, two left limit switches or proximity sensors 6, a cleaning trolley 7, a motorized winch 8 with a wire rope 9, a control system 10, rechargeable batteries 11, 12 and a parking station 13 are mounted. The mobile solar panel cleaning robot travels laterally on the frame of top and bottom edges of the solar panel 1 as shown in the figure-1.
[043] In this embodiment of the present invention as shown in figure 1 and figure-3, the control system 10 consists of a digital computer (20) with high repeatability and accuracy, a power unit

15 to power the system, a battery charging unit 16 to re charge the batteries, plurality of different kind of sensors for automated operation, motor control unit 17, a secured communication media 18 and a user friendly HMI (Human Machine Interface) 19.
[044] In another embodiment of the present invention as shown in figure-3 and figure-5, the controller consists of digital computer 20 that has multiple inputs and outputs interface, controlled by a simulated program (such as a ladder diagram, a structural text and a functional block diagram) designed in a computer which can be stored in the controller’s memory, a transistor based I/ O module 21 to provide PWM signal to control the motor speeds and direction.
[045] In this embodiment of the present invention as shown in the figure1 and 3 and figure 5, the power unit of the solar panel cleaning robot entails two numbers of on-board 12V, 24AH Sealed Lead Acid Rechargeable batteries 11,12 which are connected in parallel, a 12 -24 V DC 28 converter which comprises of a transformer to step up the voltage level from 12 V to 24V that is utilized by various sensors, a 5 V voltage regulator 29 to regulate the higher voltage levels to 5 V which is utilized by motor driver and other sensors.
[046] Further, in the embodiment of the present invention as shown in fig-3 and fig-5, the battery charging unit consists of 120Wp, 19.95V(max) standalone solar panel 25 mounted on parking station 13 is used for charging the on-board rechargeable batteries 11,12 through the stationary insulated charging contacts.
[047] In the embodiment of the mobile solar panel cleaning robot a specially devised circuit is used to power-up the solar panel cleaning robot so that it takes minimum amount of current while it is in parking station. The digital computer 20 gets continuous power from power unit 15 which in-turn power-up other components like motors 31 and sensors through one of its outputs so that these components get power only when the digital computer 20 receives an input as shown in figure-3.
[048] Another embodiment of the present invention as shown in fig-4, the mobile solar panel cleaning robot has at least one of the drive wheel at top and bottom drive each, is attached to a 360-degree high precision rotary encoder disc having number of holes 35 to detect the rotational

counts, by a proximity sensor 36, to obtain the position of wheel indicating travel of the mobile solar panel cleaning robot. The encoder senses the distance travelled by the solar panel cleaning robot and feeds it to the digital computer. The digital computer generates an error signal using the programmed value and encoder feedback and feeds this error signal to the drive wheels to self-correct the travelled distance.
[049] Moreover in the embodiment of the present invention as shown in the figure 3 and figure-5, the bottom drive and top drive of the mobile solar panel cleaning robot consists of two drive wheels (not shown) each and plurality of support wheels (not shown) arranged in a specific manner to cross the panel to panel gap. The drive wheels consist of High torque geared DC motors 31 with Metal Gearbox and Metal Gears. The motors are controlled through a precise controller 20 using a highly accurate dual dc motor driver 30 through PWM (Pulse Width Modulation). The digital computer gives PWM signal through its high speed counter. After converting the voltage level of the PWM signal as per the motor driver requirement, the PWM signal is fed to the motor driver 30 to regulate the speed of the motor 31. The motor driver also has direction and break signals with a simple TTL/CMOS based interface that can be connected directly to the digital output of the controller.
[050] In the embodiment of the present invention, in the mobile solar panel cleaning robot, there are different type of sensors 32 are used for automatic operation. There are total four limit switches 5, 6, used in Solar Panel Cleaning Robot, wherein two at left side frame of the robot and two at right side of the frame to sense the start and stop position of the solar panel cleaning robot. As soon as the roller of limit switch gets activated (while hitting the hard stop) it sends a signal to the digital computer. Further, there are in total four numbers of 24V DC proximity sensors 33,36 used, of which two are used to detect trolley top and bottom position and other two are used to count the number revolutions of the encoder disc for top and bottom drive. One number of 24V DC photoelectric switch 37 is an infrared used to detect the gap between solar panels. A 5 V DC rain sensor 34 is used to detect the rainy weather which consists of Raindrops module and Electronics module as shown in fig-5. Whenever the water drops fall on the rain drop module, the electronic module sends a signal to digital computer and the Solar Panel Cleaning Robot either does not start if at home position or returns to home position, if it is executing the cleaning process. One 5V DC current sensor is used to sense the load current. As soon as the current drawn by Solar Panel

Cleaning Robot from the batteries 11, 12 is more than a threshold value, the robot may automatically stop, and an error signal is generated.
[051] Another embodiment of the present invention, to control and/or monitor the function of the mobile solar panel cleaning robot, an HMI 19 is used to control the solar panel cleaning robot through a secured wireless connection as shown in fig-3. The HMI uses a user-interface (UI) to control the solar panel cleaning robot. Various parameters of the solar panel cleaning robot like current, voltage, no. of panels cleaned, present position of the robot, motor conditions can also be monitored using the HMI. Using the HMI, the robot can move in either auto 39 or manual mode 40. In the embodiment of the mobile solar panel cleaning robot a secured 2.4 GHz IEEE 802.11 wireless communication protocol 18 has been used for communication between the robot and HMI using a router 23 as shown in the fig-3. The front end of the HMI 19 is shown in the figure 2, which can be operated by using communication media either a mobile phone/ tablet PC or a personal computer. Additionally, in the monitor of mobile phone/tablet PC or a personal computer, various parameters of the cleaning robot is monitored as shown in fig 7a and fig 7b.
[052] In another embodiments of the present invention, the cleaning cycle consists of the mobile robot moving from its parked position to the desired cleaning position. In the cleaning position, the cleaning trolley 7 is pulled up by wire rope winch (8, 9), while the cleaning devices are rotating. The cleaning trolley after reaching the top position, is released by the motorized winch 8 and descends down the metal bar at a controlled speed, while the cleaning devices are rotating. The frictional action of the cleaning devices on the solar panel top surface removes the accumulated dust particles on the surface. After this cleaning action, the mobile robot moves horizontally on two top edges and the bottom edge of the solar panel to the new cleaning position and the cleaning cycle repeats.
[053] In another embodiment of the present invention as shown in the fig-6, the battery parameters are being monitored continuously 42. Initially, there are two reference points for voltage considered and named as Vref1 and Vref2. While running state of the robot, if the battery voltage falls below Vref2, then the robot stops its cleaning operation and returns to the parking station for charging the batteries. If, in case, the voltage falls below Vref1 then it is safe to power off the robot for safety purposes, so it sends an error signal to the HMI 19 and shuts down. Moreover, a reference

set point for current drawn from batteries is considered and named Iref. If, in case, the current drawn from the battery exceeds this set point, to safe keep the other equipment on the robot, the Digital computer 20 halts the current operation and sends report to the HMI 19.
[054] In this embodiment of the present invention as shown in fig- 8a, in the manual operation or other mode of operation 39, 43 the mobile robot is moved manually to the left or to the right directions, using a mobile phone, tablet PC or a computer connected wirelessly to the digital computer that is housed in the control panel 17. The similar manual operation is also done for the cleaning trolley to move it up or down and cleaning devices to rotate them clockwise or counter-clock wise. The manual mode of solar panel cleaning robot is also stated as either debugging mode of robot or malfunction of the robot as shown in fig-8a.
[055] In this embodiment of the present invention as shown in fig- 8b, in the automatic operation 40, 44 mode, the mobile robot moves automatically at a programmed time from its parked position to the desired cleaning position. In the cleaning position, the cleaning trolley 7 is pulled up by wire rope winch 8, while the cleaning devices are rotating. The cleaning trolley 7 after reaching the top position, is released by the motorized winch and descends down the metal bar at a controlled speed, while the cleaning devices are rotating. After the first cleaning cycle, the mobile robot moves horizontally on two top edges and the bottom edge of the solar panel to the new cleaning position and the automatic operation of new cleaning cycle begins. This operation is repeated till all the solar panels in an entire array are cleaned, the end position of which is detected by the two sensors 5 mounted at the top and bottom of the mobile robot as shown in fig-1. After the mobile robot reached its end position of the cleaning process, it automatically travels back to the parking position, where the end position is detected by the two sensors 6 mounted at the top and bottom of the mobile robot. After the mobile robot reaches its parked position in the parking station, it is automatically connected to a charging circuit 16 to charge the on-board batteries 11,12.
[056] Reference No. Patent Application 201931044665: the cited patent application claimed the cleaning robot and its function applicable to clean solar panels.

WE CLAIM:
1. An automated control system for an automated cleaning apparatus /system for solar panel,
wherein solar panel consisting of parking station (3) and cleaning system cleans the top
surface of the solar panels, the control system comprising:¬
- at least one battery charging unit (16) to recharge at least two batteries (11,12) and
at least one power unit (15) to provide power to said control system;
- at least a system unit to draw minimum current from battery during the cleaning system not in operation;
- at least a controller to control the speed of DC motor (31) through DC motor drives (30), wherein control unit (17) consisting of at least one Digital Computer (20), that has multiple inputs and outputs interface, at least one transistor based I/O (input/output) module (21) to provide PWM (Pulse Width Modulation) signal to control the motor speeds and direction;
- a plurality of sensors used for automatic and other mode of operation;
- at least one secured communication media (18); and
- at least one HMI (Human Machine Interface) to monitor various parameters of cleaning system through a secured wireless connectivity wherein, various parameters of cleaning apparatus are like current, voltage, number of panels cleaned, present position of cleaning apparatus, motor conditions and others.
2. The control system for cleaning apparatus as claimed in claim 1, wherein the
cleaning apparatus is a mobile robotic solar panel cleaning device, characterized in

that the cleaning device may travel vertically (Y-direction) for cleaning dust on the top surface of the solar panel without using water or any other chemical and after cleaning action finished, the mobile robot moves horizontally (X-direction) on top edges and the bottom edge of solar panel to the new cleaning position and the cleaning cycle repeats.
3. The cleaning apparatus as claimed in claim 2, wherein the mobile robot is configured
by consisting an encoder used for verifying the movements of the robot.
4. The cleaning apparatus as claimed in claim 2, wherein the mobile robot parks itself at least one parking station (13) to power up the cleaning apparatus so that it takes minimum amount of current.
5. The control system for an automated cleaning apparatus for solar panel as claimed in claim 1, wherein solar panel array consists of a plurality of solar panel 25 that incorporates a plurality of solar rows, wherein the solar rows being substantially parallel to each other.
6. The power unit used in the control system as claimed in claim 1, wherein the power unit of the solar panel cleaning robot entails at least two on board 12V, 24AH sealed lead acid rechargeable batteries (11, 12) which are connected in parallel at least one 12-24V DC converter that comprises of a transformer of step up the voltage level from 12V to 24V, that is utilized by a plurality of sensors, at least a voltage regulator (29) to regulate the higher voltage levels to 5V, that is utilized by motor driver circuit (30) and DC motors (31) and other sensors.

7. The battery charging unit used in control system as claimed in claim 1, wherein said battery charging unit consists of 120wp, 19.95V (max) standalone solar panel (25) mounted on parking station (13), and charge controller (27) for charging the on-board re-chargeable batteries (11,12) through the stationery insulated charging contacts.
8. The controller (17) used to control the speed of the DC motor as claimed in claim 1, wherein controller consists of Digital Computer (20) configured with multiple inputs and outputs interface, controlled by a simulated program stored in controller’s memory, a transistor based I/O (input/output) module (21) to provide PWM (Pulse Width Modulation) signal to control the motor speeds and direction,
characterized in that the Digital Computer (20) gets continuous power from power unit (15) which in turn power up other components like DC motors (31) and sensors (32) through one of its outputs so that these components get power only during the Digital Computer (20) receives an input.
9. The system unit to draw minimum current used in control system as claimed in claim 1, wherein the system unit defines a current sensor (41) connected with Digital Computer (20).
10. The communication media used in control system as claimed in claim 1, wherein the mobile solar panel cleaning robot incorporating a secured 2.4GHz, IEEE 802.11 wireless communication protocol (18) , has been used for communication between the robot and HMI (19) using a router (23), wherein the WI-FI router (23) is connected with Digital Computer (20) through a network connectivity.
11. The HMI unit used in the control system as claimed in claim 1, wherein a user friendly HMI (19) is either a portable communication device or personal computer, having the WIFI connectivity, is used to control various parameters of solar panel cleaning robot like current, voltage, number of panels cleaned, present position of

the robot, motor conditions and other, and operates in two mode as manual or automatic.
12. The control system as claimed in claim 1, wherein a rain sensor module (34) is used to detect the rain and during the raining, the mobile solar panel cleaning robot stops its functioning and return back to home position.
13. A method to monitor or control various parameters of solar panel robot by using HMI 19 automatically, as claimed in claim 11, wherein the method comprising the steps of:
- checking the battery parameters by:
a) comparing the battery voltage with Vref2 during running status of the cleaning apparatus and if battery voltage falls below Vref2, then robot stops its cleaning operation and returns to the parking station for charging the batteries, wherein reference point for voltage is considered and named Vref2;
b) comparing the battery voltage with Vref1, if battery voltage falls below Vref1, then it is safe to power off the robot for safety purposes, so it sends an error signal to HMI and shuts down, wherein reference point for voltage is considered and named Vref1;
c) comparing current drawn from the battery Iref, in case current exceeds this set
point Iref, the digital computer (20) halts the current operation and sends reports to
the HMI;
- moving the mobile robot in backward direction;
- checking if top and bottom backward limit switches are on, if both switches are in “ON” state, then send a report to HMI “cleaning Done” else again check the battery parameters; and
- connecting batteries to the solar panel 25 through the charge controller 27 to get re-charged.

14. The method for monitoring of solar panel robot by using HMI in manual or other
mode of operation as claimed in claim 11, wherein the method comprising the steps of ;
a) powering up the robot;
b) checking the battery parameters;
c) checking the rain sensors, in case it is raining, send information to HMI(19) to stop the cleaning robot and return back to home position, else check if top and bottom backward limit switches are ON;
i) in case said switches are ON, check if bottom sensor is ON or OFF;
ii) in case the top and bottom backward limit switches are OFF, move the
robot in backward direction;
d) in case bottom sensor is ON, then check the battery parameters;
e) initiating the rotation of the brushes;
f) moving the trolley (7) up and check if top sensor fixed in the cleaning robot, is ON or OFF;
- in case top sensor is in ON state, moving the trolley (7) downward direction, else move the trolley (7) upward direction;
g) moving trolley 7 down once checking the top sensor, fixed in the cleaning robot,
is in ON state;
h) checking if top and bottom forward limit switches are ON/OFF, and in case if both the switches are in ON state, check the battery parameters and repeat the steps as claimed in claim 13, else checking the battery parameters and move the robot in forward direction for the set number of counts in the encoder and repeat the steps of (d) to (h).