DESC:CROSS REFERENCE TO RELATED APPLICATION
This application is based on and derives the benefit of Indian Provisional Application no 201641040978, the contents of which are incorporated herein by reference.

TECHNICAL FIELD
[001] Embodiments herein generally relate to braking systems in vehicles and more particularly, but not exclusively to electronic low residual drag caliper for disc brake in vehicles.
BACKGROUND
[002] Generally, a disc brake is a type of brake that uses calipers to squeeze pairs of pads against a disc in order to create friction that retards the rotation of a shaft, such as a vehicle axle, either to reduce its rotational speed or to hold it stationary. During each brake application, the piston in the caliper moves the pads. When the brake is released, the clearance between the brake pad and the brake disc is reduced as the retraction is only due to seal roll back. Currently all brake manufacturers are producing low drag calipers by increasing the seal roll back chamfer angle. This affects the volume consumption of the caliper thereby causing higher pedal travel in pedal feel.

OBJECTS
[003] The principal object of embodiments herein is to disclose an electronic low residual drag caliper for a brake unit of a vehicle.
[004] Another object of embodiments herein is to disclose an electronic low residual drag caliper for a brake unit of a vehicle, without compromising the pedal feel.
[005] These and other aspects of the embodiments herein will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. It should be understood, however, that the following descriptions, while indicating at least one embodiment and numerous specific details thereof, are given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the embodiments herein without departing from the spirit thereof, and the embodiments herein include all such modifications.

BRIEF DESCRIPTION OF FIGURES
[006] Embodiments herein are illustrated in the accompanying drawings, through out which like reference letters indicate corresponding parts in the various figures. The embodiments herein will be better understood from the following description with reference to the drawings, in which:
[007] FIG. 1 depicts a brake assembly in a vehicle, according to embodiments as disclosed herein;
[008] FIG. 2 depicts an example perspective view of the brake assembly 100, according to embodiments as disclosed herein;
[009] FIG. 3 is a flowchart depicting the process of maintaining a pre-defined clearance between brake pads and brake disc present in the vehicle and/or the brake pads and the pistons, when the brake is on, according to embodiments as disclosed herein; and
[0010] FIG. 4 is a flowchart depicting the process of maintaining a pre-defined clearance between brake pads and brake disc present in the vehicle and/or the brake pads and the pistons, when the brake is off, according to embodiments as disclosed herein.

DETAILED DESCRIPTION
[0011] The embodiments herein and the various features and advantageous details thereof are explained more fully with reference to the non-limiting embodiments that are illustrated in the accompanying drawings and detailed in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.
[0012] The embodiments herein disclose an electronic low residual drag caliper for a brake unit of a vehicle. Referring now to the drawings, and more particularly to FIGS. 1 through 4, where similar reference characters denote corresponding features consistently throughout the figures, there are shown embodiments.
[0013] Embodiments herein maintain a pre-defined clearance between brake pads and brake disc present in the vehicle and/or the brake pads and the pistons. On sensing that the brake has been released, the piston can be retracted by pumping the fluid back to the brake reservoir to maintain the pre-defined clearance. When the brake is pressed, during a first stage of the brake light switching on, the piston can be pushed by reducing the clearance of the pad disc, hereby reducing the pedal travel and also achieving low residual drag caliper.
[0014] FIG. 1 depicts a brake assembly in a vehicle. The vehicle, as disclosed herein, can be any vehicle equipped with at least one disc brake. Examples of the vehicles can be, but not limited to, scooters, motorcycles, cars, vans, trucks, utility vehicles, buses, farm equipment, and so on. The brake assembly 100, as depicted, comprises of a caliper 101, a plurality of brake pads 102, a brake disc 103, a piston 105, a control unit (CU) 106, a brake light switch 107 and at least one brake light 108. The caliper 101 can further comprise of a sensor 102. In an embodiment herein, the sensor 102 can be a proximity sensor. The CU 106 can be a unit, which can control the brakes of the vehicle. The CU 106 can be any module that can monitor the brakes of the vehicle. The CU 106 can be a dedicated module or a module present in the vehicle that has been modified to perform the functions as described herein. In an embodiment herein, the CU 106 can be an electro-hydraulic unit. In an embodiment herein, the CU 106 can be the ABS (Anti-lock Braking System) motor present in the vehicle. In an embodiment herein, the CU 106 can be an ESP (Electronic Stability Program) motor. In an embodiment herein, the CU 106 can be an ABS/ESP motor. FIG. 2 depicts an example perspective view of the brake assembly 100.
[0015] In an embodiment, the CU 106 can determine the condition of the brake based on the position of the switch plunger of the brake light switch 107. In an embodiment herein, the CU 106 and the brake light switch 107 can be connected using a CAN (Controller Area Network) bus.
[0016] The sensor 102 can measure the clearance between two components in the brake assembly 100. In an embodiment herein, the sensor 102 can determine the clearance/gap between the pad 103 and the disc 104. In an embodiment herein, the sensor 102 can determine the clearance/gap between the caliper 101 and the piston 105. The gap can be maintained at a pre-defined level. The pre-defined level can be based on the required residual drag. The gap can be such that no or very minimal contact occurs between the components during maneuvering without braking of the vehicle. The CU 106 can maintain the gap by pushing/retracting the piston 105, as required.
[0017] When the brake in the vehicle is pressed (brake-on condition) and a brake light switch plunger of the brake light switch 107 travels a pre-determined distance (for example, 2.5mm), the CU 106 can push the piston 105 to maintain the clearance between the pad 103 and the disc 104 at the pre-defined level. This can improve the pedal feel.
[0018] When the brake is off or the brake is released, based on the plunger position of the brake light switch 107, the CU 106 can retract the piston, thereby increasing the clearance between the pad 103 and the disc 104 to maintain the pre-defined level. The CU 106 can retract the piston 105 by pumping fluid back to the brake reservoir. Hence achieving low residual drag in the brake caliper 101.
[0019] The sensor 102 can continuously provide feedback to the CU 106, about the current gap. Based on this feedback, the CU 106 can maintain the clearance at the re-defined level by controlling the piston 105.
[0020] FIG. 3 is a flowchart depicting the process of maintaining a pre-defined clearance between brake pads and brake disc present in the vehicle and/or the brake pads and the pistons, when the brake is on. The sensor 102 measures (301) the clearance between two components in the brake assembly 100. The sensor 102 can determine the clearance/gap between the pad 103 and the disc 104 and/or the clearance/gap between the caliper 101 and the piston 105. The gap can be maintained at the pre-defined level. On determining (302) that the brake light switch plunger of the brake light switch has travelled the pre-determined distance, the CU 106 pushes (303) the piston 105 to maintain the gap between the pad 103 and the disc 104 at the pre-defined level. The various actions in method 300 may be performed in the order presented, in a different order or simultaneously. Further, in some embodiments, some actions listed in FIG. 3 may be omitted.
[0021] FIG. 4 is a flowchart depicting the process of maintaining a pre-defined clearance between brake pads and brake disc present in the vehicle and/or the brake pads and the pistons, when the brake is off. The sensor 102 measures (401) the clearance between two components in the brake assembly 100. The sensor 102 can determine the clearance/gap between the pad 103 and the disc 104 and/or the clearance/gap between the caliper 101 and the piston 105. The gap can be maintained at the pre-defined level. On determining (402) that the brake is off or the brake is released (which can be based on the plunger position of the brake light switch 107), the CU 106 retracts (403) the piston by pumping fluid back to the brake reservoir, thereby increasing the clearance between the pad 103 and the disc 104 to maintain the pre-defined level. The various actions in method 400 may be performed in the order presented, in a different order or simultaneously. Further, in some embodiments, some actions listed in FIG. 4 may be omitted.
[0022] Embodiments herein result in a low residual drag caliper without compromising the pedal feel. Embodiments herein can lead to better fuel economy in the vehicle. Embodiments herein facilitate ease in meeting emission norms. Embodiments herein can result in avoidance of off brake Disc Thickness Variation (DTV) issues that can lead to brake judder. As the gap level can be adjusted, embodiments herein can be calibrated for vehicle-to-vehicle and caliper-to-caliper also. Embodiments herein can determine pad worn out condition and can provide corresponding indications to the driver.
[0023] The embodiments disclosed herein disclose maintaining a pre-defined clearance between brake pads and brake disc present in the vehicle and/or the brake pads and the pistons. Therefore, it is understood that the scope of the protection is extended to such a program and in addition to a computer readable means having a message therein, such computer readable storage means contain program code means for implementation of one or more steps of the method, when the program runs on a server or mobile device or any suitable programmable device. The method is implemented in at least one embodiment through or together with a software program written in e.g. Very high speed integrated circuit Hardware Description Language (VHDL) another programming language, or implemented by one or more VHDL or several software modules being executed on at least one hardware device. The hardware device can be any kind of portable device that can be programmed. The device may also include means, which could be e.g. hardware means like e.g. an ASIC, or a combination of hardware and software means, e.g. an ASIC and an FPGA, or at least one microprocessor and at least one memory with software modules located therein. The method embodiments described herein could be implemented partly in hardware and partly in software. Alternatively, the invention may be implemented on different hardware devices, e.g. using a plurality of CPUs.
[0024] The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of embodiments and examples, those skilled in the art will recognize that the embodiments and examples disclosed herein can be practiced with modification within the spirit and scope of the embodiments as described herein.

,CLAIMS:STATEMENT OF CLAIMS
I/We claim:
1. A brake assembly (100) in a vehicle, the assembly (100) comprising at least one caliper (101), at least one brake pad (103), at least one brake disc (104), a piston (105), and a brake light switch (107), wherein the caliper (101) comprise of a proximity sensor (102), the assembly configured for
monitoring a gap by the proximity sensor (102) between at least one of
the brake pad (103) and the brake disc (104); and
the caliper (101) and the piston (105);
pushing the piston (105) by a control unit (106) to maintain the gap at a pre-defined level, on the control unit (106) determining that the brake is on; and
retracting the piston (105) by the control unit to maintain the gap at the pre-defined level, on the control unit (106) determining that the brake is off.
2. The brake assembly as claimed in claim 1, wherein the pre-defined level depends on a required residual drag.
3. The brake assembly as claimed in claim 1, wherein the gap can be such that no or very minimal contact occurs between the brake pad (103) and the brake disc (104); and the caliper (101) and the piston (105); during maneuvering without braking of the vehicle.
4. The brake assembly as claimed in claim 1, wherein the control unit (106) determines that the brake is on by determining that the brake light switch (107) has travelled a pre-determined distance.

5. The brake assembly as claimed in claim 1, wherein the control unit (106) retracts the piston (105) by pumping fluid to a brake reservoir.

Dated: 27th November 2017
Signature:
Name of Signatory: Somashekar Ramakrishna