The present disclosure, in general, relates to a wiper system for a vehicle, and in particularly, a wiper assembly having a variable pressure on wiper arm so that wiper blade has variable pressure on windshield of the vehicle.
BACKGROUND
[0002] Background description includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced is prior art.
[0003] Referring to fig. 1, a wiper assembly 100 comprises a wiper arm 101 which is pivotally connected with a wiper head 102 that is rotatably mounted on a pivot shaft 106. The pivot shaft 106 is connected with a wiper lever 108 that receives rotational movement from a wiper motor (not shown in figures) via a wiper linkage 109. The wiper arm 101 has a hook end portion 110 to receive a wiper blade which comprises of rubber portion to clean windshield of the vehicle in wiping range. The wiping range is defined in between upper reverse position and lower reverse position of the wiper blade. The wiper motor has predefined mechanism to rotate the wiper arm 101 in clockwise and anticlockwise direction within the wiping range. The wiper assembly 100 has spring coil 103 that connects the wiper arm 101 and the wiper head 102 and applies pressure on the wiper arm 101 towards the windshield. Further, the tension in the spring 103 is responsible for pressure generation on the wiper arm 101.
[0004] Existing wiper assembly with spring coil has several technical disadvantages:
[0005] Technical problem: The existing wiper assembly with spring does not allow wiper arm pressure adjustment based upon change in vehicle speed. As per the requirement, the wiper arm pressure should increase with increasing vehicle speed to negate the effect of wind-lift. In the absence of increased pressure, the

pressure applied on the windshield by the wiper arm will get reduced resulting in improper cleaning.
[0006] Another technical problem associated with existing wiper assembly is in-efficient cleaning of windshield. During the movement of wiper arm along windshield surface in between the upper reverse position and lower reverse position, the wiper arm moves up and down to match the windshield curvature, due to rotation along pivot joint with wiper arm head. This results in change of length of the spring and consequently change of arm pressure as tension in the spring changes. Generally, a constant wiper arm pressure is required throughout the wiping cycle for proper cleaning of windshield. Hence, the conventional system is flawed.
[0007] Yet another technical problem associated with existing wiper assembly is in-efficient cleaning of windshield when the wiper blade changes direction at the upper reverse position and the lower reverse position. As the spring coil applies continuous pressure on the wiper arm throughout the wiping range, the wiper blade faces high resistance to change of direction at upper and lower reverse position, resultantly, smooth wiping is not achieved at upper and lower reverse position. However, pressure of the wiper arm should be less at the upper and lower reverse position as compared to other positions in the wiping range to allow easy change in direction of the wiper blade.
[0008] Yet another technical problem associated with the existing wiper assembly is damaging of wiper blade during non-use of wiper assembly for a long time. As the spring coil applies continuous pressure on the wiper arm and keep the wiper blade in contact with the windshield during non-use of the wiper assembly. After a time, wiping lip(s) of the wiper blade gets permanently deform due to continuous pressure and environmental effect, such as heat. The deformed wiping lip(s) do not provide efficient wiping performance.
[0009] In the view of the above-cited problems, there is a need for a wiper assembly with variable pressure to provide smooth wiping on the windshield and avoid deformation of the wiper blade during non-use. Accordingly, there is a need

for wiper assembly that can overcome one or more limitations stated above or any other limitation associated with the conventional prior arts.
OBJECTS OF THE DISCLOSURE
[0010] Some of the objects of the present disclosure, which at least one embodiment herein satisfy, are listed hereinbelow.
[0011] It is a general object of the present disclosure to provide a wiper assembly with a pair of magnets to achieve variable pressure on windshield by wiper arm.
[0012] It is another object of the present disclosure to provide a wiper assembly to provide smooth wiping in wiping range of the windshield.
[0013] It is another object of the present disclosure to provide a wiper assembly that can avoid permanent deformation of wiper blade during non-use for long term.
[0014] It is another object of the present disclosure to provide a variable pressure control device to control magnetic field of the pair of magnets provided in the wiper assembly to provide variable pressure.
[0015] 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
[0016] This summary is provided to introduce concepts related to a wiper assembly having a pair of magnets to provide variable pressure on windshield by wiper arm. The concepts are further described below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.

[0017] In an embodiment, the present disclosure relates to a wiper assembly for a vehicle. The wiper assembly provides a variable pressure on a wiper arm for uniform cleaning of windshield of the vehicle. The wiper assembly includes the wiper arm that is pivotally connected with a wiper arm head at one end and with a wiper blade at other end. The wiper arm comprises a magnet housing having a pair of magnets where one magnet is connected with the wiper arm and other magnet is connected with the wiper arm head. Each magnet from the pair of magnets are separated by a distance from each other. Further, a wiper arm position sensor is coupled to a pivot shaft which is rotatably coupled with the wiper arm head at one end and connected with a wiper lever at other end to transmit rotational movement from a wiper motor to the wiper arm head. A variable pressure control device that is microcontroller or a system having a processor and a memory is coupled to the pair of magnets, a Body Control Module (BCM) which may comprise Body control module and Electronic Control Unit, and Engine control unit of the vehicle, and the wiper arm position sensor to vary magnetic force between the pair of magnets by changing amount of current flow based on speed of vehicle and curvature of windshield. The variable pressure control device receives electrical power either directly from the battery or from the Body Control Module of the vehicle.
[0018] In an aspect, one of the magnet from the pair of magnets is permanent magnet.
[0019] In an aspect, atleast one magnet from the pair of magnets is an electromagnet.
[0020] In another aspect of the present subject matter, a variable pressure control device is provided to vary pressure on wiper arm of wiper arm assembly for uniform cleaning of windshield of a vehicle. The variable pressure control device comprising a variable pressure micro-controller that is coupled to a Body Control Module (BCM) and a pair of magnets. The variable pressure micro¬controller receives vehicle speed from a vehicle speed sensor coupled to the BCM and receives wiper switch ON/OFF signal from a wiper switch coupled to the

BCM. The variable pressure micro-controller also receives wiper arm position signal from a wiper arm position sensor and determines amount of current to flow in the pair of magnets according to the vehicle speed, the wiper switch ON/OFF signal, and the wiper arm position signal to provide variable pressure on the wiper arm.
[0021] In an aspect, the variable pressure micro-controller determines amount of current to flow in the pair of magnets to vary magnetic field according to the vehicle speed to counter the effect of wind lift on the wiper arm.
[0022] In an aspect, the variable pressure micro-controller determines amount of current to flow in the pair of magnets to vary magnetic field according to position of the wiper arm based on the wiper arm position signals corresponding to predetermined data or lookup table stored in the memory of the variable pressure micro-controller for uniform pressure throughout wiping cycle on the windshield.
[0023] In an aspect, the variable pressure micro-controller reduces the amount of current to vary magnetic field when the wiper arm reaches upper reverse position and lower reverse position during wiping cycle to reduce the wiper blade flip noise.
[0024] In an aspect, the variable pressure micro-controller receives security system ON/OFF signal from the BCM and changes polarity of the pair of magnets when security system is ON to generate a repulsive force to lift the wiper arm away from the windshield.
[0025] In another aspect, the present subject disclosure relates to a method for generating variable pressure on a wiper arm comprises a pair of magnets. The method comprising steps of receiving vehicle speed from a Body Control Module (BCM); receiving the wiper arm position from a wiper arm position sensor; receiving vehicle ignition ON/OFF condition from the BCM; and determining amount of current to flow in the pair of magnets, according to the vehicle speed,

the wiper switch ON/OFF signal, and the wiper arm position to provide variable pressure on the wiper arm.
[0026] In an aspect, the method further includes determining amount of current to flow in the pair of magnets to vary magnetic field according to the vehicle speed to counter effect of wind lift on the wiper arm.
[0027] In an aspect, the method further includes determining amount of current to flow in the pair of magnets to vary magnetic field according to predetermined data corresponding to position of the wiper arm and amount of current for uniform pressure on the windshield by wiper arm throughout wiping cycle on the windshield.
[0028] In an aspect, the method further includes reducing the amount of current to vary magnetic field when the wiper arm reaches upper reverse position and lower reverse position based on the wiper position during wiping cycle to reduce the wiper blade flip noise.
[0029] In an aspect, the method further includes changing polarity of the pair of magnets when the vehicle security system is ON to generate a repulsive force to lift the wiper arm away from the windshield.
[0030] 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.
[0031] It is to be understood that the aspects and embodiments of the disclosure described above may be used in any combination with each other. Several of the aspects and embodiments may be combined to form a further embodiment of the disclosure.
[0032] The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS
[0033] The accompanying drawings, which are incorporated in and constitute a part of this disclosure, illustrate exemplary embodiments and, together with the description, serve to explain the disclosed principles. In the figures, the left-most digit(s) of a reference number identifies the figure in which the reference number first appears. The same numbers are used throughout the figures to reference like features and components. Some embodiments of system and/or methods in accordance with embodiments of the present subject matter are now described, by way of example only, and with reference to the accompanying figures, in which:
[0034] FIG. 1 illustrates conventional wiper assembly with spring coil as known in the art;
[0035] FIG. 2 illustrates a wiper assembly with a pair of magnets, in accordance with an embodiment of the present disclosure;
[0036] FIG. 3 illustrates bottom view of the wiper assembly with magnet housing of fig. 2, in accordance with an embodiment of the present disclosure;
[0037] FIG. 4 illustrates a wiper assembly having a pair of magnets where both magnets are electromagnets, in accordance with an embodiment of the present disclosure;
[0038] FIG. 5 and 6 illustrate a wiper assembly having a pair of magnets where one magnet is electromagnet and other is permanent magnet, in accordance with an embodiment of the present disclosure;
[0039] FIG. 7 illustrates a system architect of the variable pressure control device coupled with wiper assembly and the Body Control Module (BCM), in accordance with an embodiment of the present disclosure;
[0040] FIG. 8 illustrates a method for working of the variable pressure control device of the fig. 7, in accordance with an embodiment of the present disclosure;

[0041] FIG. 9 illustrates a method for varying magnetic force based on wiper position on windshield of the method of fig. 8, in accordance with an embodiment of the present disclosure;
[0042] Fig. 10 illustrates a method for varying magnetic force based on vehicle speed on windshield of the method of fig. 8, in accordance with an embodiment of the present disclosure; and
[0043] Fig. 11 illustrates a method for generating repulsive magnetic force in between the pair of magnets when vehicle security system is in ON condition, in accordance with an embodiment of the present disclosure.
[0044] It should be appreciated by those skilled in the art that any block diagrams herein represent conceptual views of illustrative systems embodying the principles of the present subject matter. Similarly, it will be appreciated that any flow charts, flow diagrams, state transition diagrams, pseudo code, and the like represent various processes which may be substantially represented in a computer-readable medium and executed by a computer or processor, whether or not such computer or processor is explicitly shown.
DETAILED DESCRIPTION
[0045] 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.
[0046] 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.
[0047] 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" 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.
[0048] 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.
[0049] 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.
[0050] Body Control Module (BCM): Body Control Module (BCM) is a central processor-based power distribution center that supervises and controls functions related to the car body, such as lights, wiper switch, windows, security, door locks and access control, and various comfort controls, such as HVAC and infotainment system. The central BCM also operates as a gateway for bus and network interfaces to interact with remote electronic control units (ECU) for other

systems. Therefore, the BCM is in direct communication with the ECU via LIN or CAN communication mode to control other loads of the vehicle.
[0051] Micro-Controller: It is a compact integrated circuit designed to govern a specific operation in an embedded system. A typical microcontroller includes a processor, memory and input/output (I/O) peripherals on a single chip. Generally, microcontrollers are designed to be readily usable without additional computing components because they are designed with sufficient onboard memory as well as offering pins for general I/O operations, so they can directly interface with sensors and other components.
[0052] Embodiments explained herein pertain to a wiper assembly of a vehicle in which the wiper blade is provided for wiping windshield of the vehicle.
[0053] FIG. 2 illustrates wiper assembly with variable pressure on windshield by wiper arm. As shown in FIG. 2, the wiper assembly 200 comprises a wiper arm 201 and a wiper arm head 202. The wiper arm 201 is pivotally connected with the wiper arm head 202 at one end and a wiper blade (not shown in figures). The wiper blade is pivotally connected with the wiper arm. The wiper arm head 202 is rotatably connected with a pivot shaft 207 using nut 206. The pivot shaft 207 is provided in a pivot holder 208 which allows rotation of the pivot shaft 207. The pivot shaft 207 is connected with a wiper lever 210 that is connected with the wiper motor (not shown in figures) via a wiper linkage 211. The wiper linkage 211 transfers the rotatable motion of the wiper motor to the pivot shaft 207 that is connected with the wiper arm head 202 to transfer the motion.
[0054] A wiper arm position sensor 209 is coupled to the pivot shaft 207 to measure rotational movement of the pivot shaft 207 which is rotatably coupled with the wiper arm head 202. The wiper arm position sensor 209 is positioned along pivot shaft holder 208 and transmits measured rotational movement to a variable pressure control device 300 (as shown in figure 7). With movement of the wiper arm head 202, the wiper arm 201 moves accordingly, therefore, movement of the wiper arm 201 can be recorded by the wiper arm position sensor 209.

[0055] As shown in the fig.2 and fig. 3, the wiper arm 201 comprises a magnet housing 203 comprising a pair of magnets 204, 205 where one magnet 204 from the pair of magnets 204, 205 is connected with the wiper arm 201 and other magnet 205 from the pair of magnets 204, 205 is connected with the wiper arm head 202.
[0056] Referring to fig. 4, as per one embodiment of the present disclosure, both magnets in the pair of magnets 204, 205 are electromagnets. Both the magnets receive current from the variable pressure control device 300 which is coupled with a body control module (BCM) of the vehicle.
[0057] Referring to fig. 5 and 6, as per another embodiment of the present disclosure, one magnet from the pair of magnets 204, 205 is permanent magnet.
[0058] As shown in the figures, both the magnets are spaced apart from each other by a distance. During attractive magnetic force, both the magnets have opposite polarity and magnitude of magnetic force is controlled by varying amount of current flow in atleast one electromagnet in the pair of magnets 204, 205. Further, generation of magnetic force by electromagnets is well known.
[0059] Referring to fig. 7, the variable pressure control device 300 can be implemented in Body Control Module 400. In another embodiment, the variable pressure control device 300 can be a standalone device system that is in communication with the BCM 400, the wiper arm position sensor 600, and a pair of electromagnets 700 via CAN bus or direct connection. The variable pressure control device 300 (hereinafter can be referred as device 300) includes variable pressure micro-controller 301 and a data 302.
[0060] In an embodiment, implementation of the present subject matter is not limited to micro-controller, it can be implemented in other processing units. In place of micro-controller 301, the device 300 may have a processor(s), an interface(s), and a memory which are working together to achieve the function, i.e., varying magnetic force between the pair of magnets.

[0061] The data 302 may include data that is either stored or generated as a result of functionalities implemented by the variable pressure micro-controller 301. Additionally, data 302 can be organized using data models, such as relational or hierarchical data models. The data 302 may store data, including temporary data and temporary files, generated by the variable pressure micro-controller for performing the various functions of the device 300.
[0062] As shown in the fig. 7, the device 300 is coupled with a body control module (BCM) 400, the wiper arm position sensor 600, and the wiper assembly 700 (same as wiper assembly 200) having a pair of magnets. The device 300 receives electrical power from the auxiliary battery of the vehicle via direct connection. In another embodiment, the device 300 receives electrical power from the auxiliary battery of the vehicle via BCM 400.
[0063] In operation, the variable pressure microcontroller 301 receives inputs vehicle speed signal 401, vehicle security system ON/OFF signal 402, wiper switch ON/OFF signal 403 from the BCM 400. The BCM 400 is coupled with the vehicle speed sensor, security system and wiper switch to control their functions. The variable pressure microcontroller 301 also receives wiper arm position signal from the wiper arm position sensor 600.
[0064] Based on the vehicle security system ON/OFF signal 402, the variable pressure microcontroller 301 determine whether vehicle is in use or idle. In an aspect, the variable pressure microcontroller 301 may take vehicle ignition ON/OFF signal to determine whether vehicle is in use or idle condition. Both the vehicle security system ON/OFF signal and vehicle ignition ON/OFF signal can be used together or separately or individually to determine whether vehicle is in use or in idle condition.
[0065] When vehicle is in use, based on vehicle security OFF signal, the variable pressure microcontroller 301 receives vehicle speed signal 401 from the BCM 400. Based on the vehicle speed, the variable pressure microcontroller 301 determines the amount of current to flow in the pair of magnets 204, 205 to generate magnetic force of attraction to provide pressure on the wiper arm 201 to

nullify the effect of wind lift on the wiper arm 201. A lookup table is stored in the variable pressure microcontroller 301 having information about the amount of current flow with respect to vehicle speed. Based on the vehicle speed, the variable pressure microcontroller 301 determine the current to flow in the pair of magnets by referring the above mentioned lookup table.
[0066] When vehicle is in use and wiper switch is ON based on the wiper switch ON signal, the variable pressure microcontroller 301 detects the wiper arm 201 position on the windshield based on the inputs received from the wiper arm position sensor 600. A lookup table corresponding to inputs from the wiper arm position sensor 600 and curvature of the windshield is pre-stored in memory of the variable pressure microcontroller 301 for processing. Further, the lookup table have information of the wiper arm position along with the vehicle speed and curvature of windshield. The variable pressure microcontroller 301 determine the amount of current to flow in the pair of magnets to generate magnetic force to provide pressure on the wiper arm 201 according to curvature of the windshield to achieve smooth wiping of windshield by applying same pressure throughout the wiping range.
[0067] The variable pressure microcontroller 301 determines upper reverse position and lower reverse position of the wiper blade on the windshield based on the inputs from the wiper arm position sensor 600 and referring the pre-stored look-up table. The variable pressure microcontroller 301 determines the current flow in the pair of magnets, at the upper reverse position and at the lower reverse position of the wiper blade on the windshield, to vary the magnetic force to reduce the pressure on the wiper arm 201 for smooth reversing of the wiper blade. With present reducing pressure at the upper reverse position and at the lower reverse position of the wiper blade on the windshield, the wiper blade flip over noise may be reduced. Further, the smooth wiping may be achieved at the upper reverse position and at the lower reverse position of the wiper blade on the windshield.
[0068] The variable pressure micro-controller 301 determines that the vehicle is not in use based on the vehicle security system ON signal or Vehicle ignition

OFF signal. Upon determining that vehicle is not in use, the variable pressure micro-controller 301 changes flow of current in one of the magnets from the pair of magnets to change its polarity resultantly generating a repulsive magnetic force between the pair of magnets. The repulsive force provides pressure on the wiper arm 201 in opposite direction to lift-up the wiper arm 201 and the wiper blade away from the windshield. By lifting up the wiper blade away from the windshield, permanent deformation of wiping lip(s) of the wiper blade which is rubber element can be prevented during no use of vehicle for long duration.
[0069] FIG. 8 illustrates a method 800 for implementing a variable pressure control device 300 with a wiper assembly 200 (700 of fig. 7), according to an embodiment of the present disclosure. The order in which the method 800 is described is not intended to be construed as a limitation, and any number of the described method blocks can be combined in any appropriate order to carry out the method 800 or an alternative method. Additionally, individual blocks may be deleted from the method 800 without departing from the scope of the subject matter described herein.
[0070] At block 802, the method includes determining, by the variable pressure microcontroller 301, whether the vehicle is in Idle condition or in use based on inputs received from the vehicle security system ON/OFF signal. When the vehicle security system is in OFF condition which means the vehicle is in use, the method proceeds to block 808 and when the vehicle is not in use, the method proceeds to block 804.
[0071] At block 804, the method includes ensuring such polarity of the pair of magnets 204 to generate a repulsive force to provide pressure on the wiper arm to lift away from the windshield.
[0072] At block 808, the method includes detecting whether wiper switch is ON or OFF. When the wiper switch is ON, the method proceeds to block 810. When the wiper switch is OFF, the method proceeds to block 806.

[0073] At block 806, the method includes determining amount of current supplied in the pair of magnets to ensure force of attraction between the magnets based on the speed of vehicle to negate the effect of wind-lift on the wiper arm.
[0074] At the block 810, the method includes receiving vehicle speed and wiper arm position on the windshield based on the inputs received from the wiper arm position sensor 600. The amount of current supplied in the pair of magnets is determined by referring the lookup table corresponding to signals from the wiper arm position sensor and vehicle speed.
[0075] At block 812, the method includes determining the amount of current to flow in the pair of magnets by referring the pre-stored lookup table corresponding to current vehicle speed and the wiper position on the windshield. Based on the amount of current flow, the magnetic attractive force is generated to provide pressure on the wiper arm according to curvature of the windshield and vehicle speed.
[0076] Referring to fig. 9, illustrating a method for providing same pressure on the wiper arm along complete wiping range on the windshield.
[0077] At block 902, the method includes receiving vehicle speed from the Body Control Module (BCM).
[0078] At block 904, the method includes receiving wiper switch ON signal from the BCM.
[0079] At block 906, the method includes receiving wiper arm position from the wiper arm position sensor. The variable pressure micro-controller 301 determines wiper arm position on the curvature of the windshield by mapping the inputs received from the wiper arm position sensor with the pre-stored lookup table having information about the windshield curvature corresponding the wiper arm position sensor signals.
[0080] At block 908, the method includes determining amount of current to flow in the pair of magnets to generate magnetic attractive force to provide variable pressure on the wiper arm on the curvature of the windshield. The

variable pressure micro-controller 301 refers the lookup table using vehicle speed and the wiper arm position to determine the amount of current to flow in the pair of magnets based on the position of the wiper arm on the windshield.
[0081] With the present method, a uniform pressure is applied on the windshield by the wiper arm during wiping cycle for uniform cleaning of the windshield.
[0082] Referring to fig. 10, illustrating a method for providing pressure on the wiper arm during no use of wiper to negate the wind-lift effect on the wiper assembly.
[0083] At block 1002, the method includes receiving vehicle security system OFF condition to ensure that the vehicle is being used. Further, the vehicle ignition ON/OFF signals can be used to determine vehicle condition.
[0084] At block 1004, the method includes receiving vehicle speed signal from the Body control module (BCM) to determine speed of the vehicle.
[0085] At block 1006, the method includes determining amount of current flow in the pair of magnets to generate magnetic attractive force to provide pressure on the wiper arm to negate/nullify the wind lift effect. The variable pressure micro-controller refers a pre-stored lookup table having information about vehicle speed versus amount of current to flow to determine the amount of current to generate magnetic attractive force.
[0086] With the present method 1000, necessary pressure is provided on the wiper arm so that pressure on the windshield is not reduced due to wind pressure (wind lift phenomenon).
[0087] Referring to fig. 11, illustrating a method 1100 for reducing pressure on the wiper arm during idle condition or parking of vehicle for long duration to prevent permanent damage of wiper blade.
[0088] At block 1102, the method includes receiving vehicle security system ON signal to determine whether the vehicle is in Idle condition.

[0089] At block 1104, the method includes supplying current to the pair of magnets to create repulsive force to provide pressure in opposite direction so that the wiper blade lift away from the windshield. Keeping the wiper blade away from the windshield during idle condition for long duration prevent the permanent damage of the wiper blade.
[0090] With the present wiper assembly with variable pressure control device, a uniform wiping performance by the wiper blade can be achieved.
[0091] The above description does not provide specific details of the manufacture or design of the various components. Those of skill in the art are familiar with such details, and unless departures from those techniques are set out, techniques, known, related art or later developed designs and materials should be employed. Those in the art can choose suitable manufacturing and design details.
[0092] It should be understood, however, that all of these and similar terms are to be associated with the appropriate physical quantities and are merely convenient labels applied to these quantities. Unless specifically stated otherwise, as apparent from the discussion herein, it is appreciated that throughout the description, discussions utilizing terms such as "receiving," or "determining," or "retrieving," or "controlling," or "comparing," or the like, refer to the action and processes of an electronic control unit, or similar electronic device, that manipulates and transforms data represented as physical (electronic) quantities within the control unit's registers and memories into other data similarly represented as physical quantities within the control unit memories or registers or other such information storage, transmission or display devices.
[0093] Further, the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. It will be appreciated that several of the above-disclosed and other features and functions, or alternatives thereof, may be combined into other systems or applications. Various presently unforeseen or unanticipated alternatives, modifications, variations, or improvements therein may subsequently be made by

those skilled in the art without departing from the scope of the present disclosure as encompassed by the following claims.
[0094] It will be appreciated that variants of the above-disclosed and other features and functions, or alternatives thereof, may be combined into many other different systems or applications. Various presently unforeseen or unanticipated alternatives, modifications, variations, or improvements therein may be subsequently made by those skilled in the art which are also intended to be encompassed by the following claims.
[0095] The claims, as originally presented and as they may be amended, encompass variations, alternatives, modifications, improvements, equivalents, and substantial equivalents of the embodiments and teachings disclosed herein, including those that are presently unforeseen or unappreciated, and that, for example, may arise from applicants/patentees and others.

We claim:

1. A wiper assembly (200) with a variable pressure on windshield by a wiper
arm (201) for uniform cleaning of the windshield of a vehicle, the wiper
assembly (200) comprising:
the wiper arm (201) pivotally connected with a wiper arm head (202) at one end and a wiper blade provided at other end, the wiper arm (201) comprises:
a magnet housing (203) comprising a pair of magnets (204, 205)
where one magnet (204) from the pair of magnets (204, 205)
connected with the wiper arm (201) and other magnet (205) from the
pair of magnets (204, 205) connected with the wiper arm head (202);
a wiper arm position sensor (209) coupled to a pivot shaft (207) which
is rotatably coupled with the wiper arm head (202) at one end and connected
with a wiper lever (210) at other end to transmit rotational movement from a
wiper motor;
a variable pressure control device (300) including a variable pressure micro-controller (301), the variable pressure control device (300) coupled to the pair of magnets (204, 205), a Body Control Module (BCM) of the vehicle, and the wiper arm position sensor (209) to:
vary magnetic force between the pair of magnets (204, 205), by changing amount of current flow in between the pair of magnets (204, 205), based on speed of vehicle and curvature of windshield to provide variable pressure on the wiper arm (201).
2. The wiper assembly (200) as claimed in claim 1, wherein one of the magnet from the pair of magnets (204, 205) is permanent magnet.
3. The wiper assembly (200) as claimed in claim 1, wherein atleast one magnet from the pair of magnets (204, 205) is an electromagnet.
4. A variable pressure control device (300) for variable pressure on a wiper arm (201) for uniform cleaning of windshield of a vehicle, the variable pressure control device (300) comprising:

a variable pressure micro-controller (301) coupled to a Body Control Unit (BCM) (400) and a pair of magnets (204, 205), the variable pressure micro-controller (301):
receives vehicle speed signal (401) from the BCM (400);
receives wiper switch ON/OFF signal (403) from a wiper switch coupled to the BCM (400);
receives wiper arm position signal from a wiper arm position sensor (600); and
determines, amount of current to flow in the pair of magnets to generate magnetic field, according to the vehicle speed, the wiper switch ON/OFF signal (403), and the wiper arm position to vary pressure on the wiper arm (201).
5. The variable pressure control device (300) as claimed in claim 4, wherein the variable pressure micro-controller (301) determines amount of current to flow in the pair of magnets (204, 205) to vary magnetic field according to the vehicle speed to counter effect of wind lift on the wiper arm (201).
6. The variable pressure control device (300) as claimed in claim 4, wherein the variable pressure micro-controller (301) determines amount of current to flow in the pair of magnets (204, 205) to vary magnetic field according to position of the wiper arm (201) on the windshield and predetermined data corresponding to position of the wiper arm (201) on the windshield stored in memory for uniform pressure throughout wiping cycle on the windshield.
7. The variable pressure control device (300) as claimed in claim 4, wherein the variable pressure micro-controller (301) reduces the amount of current flow in the pair of magnets (204, 205) to vary magnetic field when the wiper arm (201) reaches upper reverse position and lower reverse position during wiping cycle to reduce the wiper blade (201) flip noise.
8. The variable pressure control device (300) as claimed in claim 4, wherein the variable pressure micro-controller (301):
receives vehicle security system ON/OFF signal (402) from the BCM (400); and

supply current to the pair of magnets (204, 205) when the vehicle security system is ON condition to generate a repulsive force to lift the wiper arm (201) away from the windshield.
9. The variable pressure control device (300) as claimed in claim 4, wherein atleast one magnet from the pair of magnets (204, 205) is electromagnet.
10. A method (800, 900, 1000, 1100) for generating variable pressure on a wiper arm (201) of a vehicle, the wiper arm (201) comprises a magnet housing (203) including a pair of magnets (204, 205) where one magnet (204) from the pair of magnets (204, 205) connected with the wiper arm (201) and other magnet (205) from the pair of magnets (204, 205) connected with the wiper arm head (202) to generate variable pressure on the wiper arm (201), the method (800, 900, 1000, 1100) comprising:
receiving (902), by variable pressure micro-controller (301), vehicle speed from a Body Control Module (400);
receiving (906), by the variable pressure micro-controller (301), the wiper arm position from a wiper arm position sensor (600);
receiving (1002), by the variable pressure micro-controller (301), vehicle security system ON/OFF signal from the Body Control Module (BCM); and
determining (908, 1006), by the variable pressure micro-controller (301), amount of current to flow in the pair of magnets (204, 205), according to the vehicle speed, the wiper switch ON/OFF signal, and the wiper arm position to generate magnetic force to provide variable pressure on the wiper arm (201).
11. The method (800, 900, 1000, 1100) as claimed in claim 10, wherein the method (800, 900, 1000, 1100) includes determining (1006), by the variable pressure micro-controller (301), amount of current to flow in the pair of magnets (204, 205) to vary magnetic field according to the vehicle speed to counter effect of wind lift on the wiper arm (201).
12. The method (800, 900, 1000, 1100) as claimed in claim 10, wherein the method (800, 900, 1000, 1100) includes determining (908) amount of

current to flow in the pair of magnets (204, 205) to vary magnetic field according to predetermined data corresponding to position of the wiper arm (201) and amount of current for uniform pressure on the wiper arm (201) throughout wiping cycle on the windshield.
13. The method (800, 900, 1000, 1100) as claimed in claim 10, wherein the method (800, 900, 1000, 1100) includes reducing the amount of current to vary magnetic field when the wiper arm (201) reaches upper reverse position and lower reverse position based on the wiper position during wiping cycle to reduce the wiper blade flip noise.
14. The method (800, 900, 1000, 1100) as claimed in claim 10, wherein the method (800, 900, 1000, 1100) includes changing (1104) polarity of the pair of magnets (204, 205) when the vehicle security system is in OFF condition to generate a repulsive force to lift the wiper arm (201) away from the windshield.