TECHNICAL FIELD

[001] The present subject matter relates to a vehicle, more particularly, to a braking system for the vehicle.

BACKGROUND [002] Conventional vehicles have a manual braking system which requires the rider to apply brakes manually to the front wheel or rear wheel of a vehicle. However, in recent times, the manual braking systems have been replaced with combination braking systems which are electronically controlled. Even though these electronically controlled brakes are preferable to use, they still include lot of system lag during braking response. Hence, an improved electronically controlled braking system is preferred.

BRIEF DESCRIPTION OF THE DRAWINGS

[003] The present invention is described with reference to a block diagram and a flow chart. This invention is implementable in two-wheeled vehicles/three- wheeled vehicles or four-wheeled vehicles. The same numbers are used throughout the drawings to reference like features and components. Further, the inventive features of the invention are outlined in the appended claims.

[004] Figure 1 illustrates a block diagram of a braking system of a vehicle, in accordance with an embodiment of the present subject matter. [005] Figure 2A and Figure 2B illustrate a flow chart depicting method of braking incorporated by the braking system in the vehicle, in accordance with an embodiment of the present subject matter.

DETAILED DESCRIPTION [006] Pollution from internal combustion engines has become a significant concern in recent times. Road transport vehicles generate large amount of pollutants as well as significant amount of noise. Efforts are being made to provide electric vehicles and hybrid electric vehicles which does not discharge harmful emissions. Electric vehicles provide a means for transportation that do not emit any substantially pollutants and generates much less noise.

[007] Electric vehicles and the hybrid electric vehicles provide the possibility of recovering vehicle kinetic energy. When the vehicle drives in heavy traffic, more than half of the energy is dissipated in the brakes. Therefore, recovering braking energy is an effective approach for increasing the driving range of electric vehicles and hybrid electric vehicles.

[008] In the existing design of hybrid electric vehicles and electric vehicles, a system of combination brakes is used. In such systems, when a front brake is applied, a rear brake is also applied and vice versa. However, during the operation of combination brakes, the mechanical brake may be released after the required duration, but the braking signal to the ECU may still be ON. Hence, this leads to the problem of false brake detection.

[009] A problem of false brake detection arises in a combination brake system when, a brake has been released mechanically, yet the ECU displays braking signal to be ON to the rider. This leads to confusion and unnecessarily application of continuous brakes by the rider which may eventually damage the entire braking system.

[010] In an existing design of a conventional internal combustion engine vehicle with mechanical brake application, the brake is applied when a rider encounters a pothole or a bump or an obstacle. At this instant, the speed of the vehicle is also low in order to cross over the pothole or the bump. This causes simultaneous application of brakes as well as throttle to slow down the vehicle. In such a braking system, the brakes are solely controlled and the vehicle is slowed down after application of the brakes.

[Oil] Additionally, in an existing design of the electric vehicle or the hybrid electric vehicle, the electronically controlled brakes are applied by the rider while encountering a pothole or a bump or during intended stop. Once this electronically controlled braking system receives a brake signal, it sends a braking signal and actuates the brakes to be applied. However, the electronically controlled system further comprehends the application of braking signal with an additional action of cutting off the vehicle power. This may lead to abrupt shut down of the entire vehicle and other vehicle systems. This can cause the vehicle to be disbalanced and therefore the rider may lose the grip, vehicle may topple and fall.

[012] In the scenario described above, in many cases the control unit controlling the electronic braking systems of the electric vehicle or the hybrid electric vehicle is unable to decipher the true braking event and thereby true brake detection does not occur.

[013] Additionally, the determination of braking signal alone to determine the true braking event does not solve the problems of true brake detection. Therefore, there is a need to determine other vehicle parameters along with the braking signal in order to determine the true braking event.

[014] As explained above for energy conservation for the electric and hybrid vehicles, after the determination of the true braking intent, in order to recover the braking energy, a regenerative braking mechanism is activated to regenerate the energy produced during braking. Many methods and systems for regeneration of braking energy are available in the existing technology. For example, one system for controlling regenerative braking is disclosed in a prior art which explains a regenerative braking control system which individually controls braking force and recharging energy. In this system, optimal braking force and optimal charging current are set based on the charge of the battery and motor speed. However, in the existing electric vehicle, once the brake switch is sensed, electric power train is disabled and regeneration is enabled. Sometimes, this may lead to problems like on- slope traffic mishandling of the vehicle and to additional inaccurate reading of braking signals which hampers the detection of the true braking event.

[015] Hence, it is an object of the present invention to overcome all the above stated and other related problems in the braking system of the electric vehicles or the hybrid electric vehicles as well as other problems of known art.

[016] It is further an object of the present invention to resolve the problems of brake signal malfunctions and determine the true braking intent in consideration with other vehicle parameters. [017] It is further an object of the present invention to provide good control over the vehicle in slope as well as in traffic.

[018] It is further an object of the present invention to provide active regeneration of braking system after sensing additional vehicle parameters along with the braking signal.

[019] As per an aspect of the present invention, an improved braking system is disclosed which is configured to provide a method for braking in a vehicle comprising the steps of detecting, using one or more sensors, one or more vehicle parameters and determining, using a control unit, a true braking event based on said one or more vehicle parameters. Said method also include the step of initiating a braking signal, using the control unit in the true braking event.

[020] The said one or more vehicle parameters detected are vehicle real time RPM (Revolutions per minute) value, real time throttle position value, real time vehicle speed value, real time brake signal value generated by a brake module and a deceleration rate value of the vehicle.

[021] As per the further embodiment, the true braking event is determined by comparing, using the control unit, the vehicle RPM (Revolution per minute) with a predefined threshold vehicle RPM value and comparing, using the control unit the throttle position value with a predefined throttle position value if the vehicle RPM value is more than the predefined threshold vehicle RPM value. Thereafter the control unit checks the availability of the brake signal, in the event if the throttle position value is more than the predefined throttle position value and then calculates a real time deceleration rate of the vehicle if the brake signal is available. Further the control unit compares the real time deceleration rate with a predetermined threshold deceleration rate value to identify the true braking event if the deceleration rate is more than the predetermined threshold deceleration rate value. The real time deceleration rate is estimated by the electronic control unit using the real time vehicle speed values over an interval of time.

[022] Further, the claimed method includes the step of generating a no brake application signal using the electronic control unit, when the real time vehicle RPM (Revolution per minute) is less than the predefined threshold vehicle RPM value. Subsequently, if the real time throttle position value is less than the predefined throttle position value the vehicle is stopped by the electronic control unit.

[023] Further, if the real time throttle position value is more than the predefined throttle position value, the no brake application signal is generated.

[024] It is another objective of the present invention to provide, a braking system comprising the brake module and the electronic control unit in which, the electronic control unit is configured to activate the brake module only in a true braking event using the method as discussed above

[025] In accordance with this configuration, one of the advantages of the present invention is that the true braking event occurs and no irregularity of braking signals and braking mechanism occurs further.

[026] In accordance with this configuration, one of the advantages of the present invention is that it provides good control during brake signal malfunction for example when someone keeps his finger on brake lever while going on a rough road. [027] In accordance with this configuration, one of the advantages of the present invention is that it gives good control over the vehicle in slope as well as traffic and further prevents signal losses during communication of ECU with other vehicle components.

[028] In accordance with this configuration, one of the advantages of the present invention is that in a vehicle with combination braking system, the kinetic energy from the braking is not wasted as active regeneration occurs once the brake signal is applied. Further, the braking of the front wheel and the rear wheel occurs at the same time.

[029] In accordance with this configuration, one of the advantages of the present invention is that it provides higher performance, comfort and braking ability to the rider while riding the vehicle.

[030] The present subject matter is further described with reference to accompanying figures. It should be noted that the description and figures merely illustrate the principles of the present subject matter. Various arrangements may be devised that, although not explicitly described or shown herein, encompass the principles of the present subject matter. Moreover, all statements herein reciting principles, aspects, and examples of the present subject matter, as well as specific examples thereof, are intended to encompass equivalents thereof.

[031] The foregoing disclosure is not intended to limit the present disclosure to the precise forms or particular fields of use disclosed. As such, it is contemplated that various alternate embodiments and/or modifications to the present disclosure, whether explicitly described or implied herein, are possible in light of the disclosure. Having thus described embodiments of the present disclosure, a person of ordinary skill in the art will recognize that changes may be made in form and detail without departing from the scope of the present disclosure. Thus, the present disclosure is limited only by the claims.

[032] Additionally, all numerical terms, such as, but not limited to, “first”, “second”, “third”, “primary”, “secondary”, “main” or any other ordinary and/or numerical terms, should also be taken only as identifiers, to assist the reader's understanding of the various elements, embodiments, variations and/or modifications of the present disclosure, and may not create any limitations, particularly as to the order, or preference, of any element, embodiment, variation and/or modification relative to, or over, another element, embodiment, variation and/or modification.

[033] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[034] Figure 1 illustrates a block diagram of a braking system in a vehicle, in accordance with an embodiment of the present subject matter. The braking system involves interaction of a battery (9), a motor (10), a throttle position sensor (1), a brake module (2), and a vehicle speed signal sensor (3) with an electronic control unit (hereinafter ECU) (7). The said throttle position sensor (1), said brake module (2), said battery (9), said motor (10) and the said vehicle speed signal sensor (3) are configured to be communicatively connected to the Electronic Control Unit (ECU)

(7).

[035] The battery (9) supplies power to drive the motor (10) to run the vehicle. The throttle position sensor (1) determines the current status of a throttle which signals the status of the throttle to the said ECU (7). The brake module (2) is configured to provide a brake signal to start or stop the vehicle, based on the application of brakes by the user to the ECU (7) which after receiving the brake signal and based on other parameters of the vehicle determines the true braking event and reduces the supply from battery to motor, in order to reduce the speed of the vehicle.

[036] The ECU (7) includes an accelerometer (6), a logic unit for accelerator sensing (5), a secondary logic unit (11), a control module (4), and an inverter block (8).

[037] The accelerometer (6) is configured to determine the vehicle acceleration and send the determined value to the logic unit for acceleration sensing (5) to proceed received value. In an embodiment, if the accelerometer is not present in the vehicle, the logic unit for acceleration sensing (5) determines the deceleration of the vehicle based on the vehicle traction parameter using any known method.

[038] The secondary logic unit ( 11 ) is configured to determine a deceleration rate value of the vehicle by calculating the average vehicle speed over time based on inputs received from the vehicle speed sensor unit (3).

[039] The control module (4) is configured to receive inputs from the logic unit for acceleration sensing (5), the secondary logic unit (11), the throttle position sensor (1) and the brake module (1). The control module (4) is configured to identify the true baking event and false braking events, based on one or more inputs received from the logic unit for acceleration sensing (5), the secondary logic unit (11), the throttle position sensor (1) and the brake module (2) and send an output to the inverter block (8).

[040] The inverter block (8) is configured to analyze the received input from the control module (4) and commands the ECU (7) to perform the braking operations if the true braking event is determined by controlling the battery (9) output to the motor (10) or directly controlling the motor (10) speed and initiates a regeneration mode to regenerate the brake energy.

[041] When the brake is pressed, the kinetic energy is generated, which generally gets wasted. Regenerative braking is an energy recovery mechanism that slows down the moving vehicle or object by converting its kinetic energy into a form that can be either used immediately or stored until needed. In this mechanism, the electric traction motor uses the vehicle's momentum to recover energy that would otherwise be lost to the brake discs as heat. Therefore, as an objective of the present invention, in the regeneration mode, the kinetic energy generated during braking is given back to the battery (9) to replenish the energy.

[042] The ECU (7) is configured to receive one or more vehicle parameters from one or more sensors employed with different vehicle components as stated above. Said one or more vehicle parameters includes a real time vehicle RPM (Revolutions per minute) value, a real time throttle position value, a real time vehicle speed value, a real time brake signal value generated by a brake module (2) and a real time deceleration rate value of the vehicle.

[043] The ECU (7) is configured to determine the true braking event based on said one or more vehicle parameters using the steps as explained using the flow chart of Figure 2A and 2B.

[044] Figure 2A and 2B illustrate the flow chart depicting method of braking incorporated by the braking system of the vehicle, in accordance with an embodiment of the present subject matter. The method for braking in the vehicle includes detection and calibration of numerous vehicle parameters to determine a true braking event of the vehicle.

[045] In order to determine the true braking event, in step (002), the ECU (7) detects of the one or more vehicle parameters using one or more sensors. The one or more vehicle parameters includes the real time vehicle RPM (Revolutions per minute) value, the real time throttle position value, the real time vehicle speed value, the real time brake signal, and the real time deceleration rate value of the vehicle. [046] After detecting the abovementioned vehicle parameters in the step (003), the ECU (7) compares the real time vehicle RPM (Vrpm) with a predefined vehicle RPM value (RPM th). The predefined vehicle RPM value (RPM th) is pre-fed to the control module (4) of the ECU (7)

[047] If the vehicle RPM value (Vrpm) is less than the predefined vehicle RPM value (RPM_th), in step (004), the ECU (7) generates a no brake application signal and the motor continues with the existing speed thereby avoiding wastage of energy which would have otherwise been applied in known art.

[048] If the vehicle RPM value (Vrpm) is greater than the predefined vehicle RPM value (Vrpm th), the ECU (7) further compares the real time throttle position value (TPS) with a predefined throttle position value (TPS th) in step (005). The predefined vehicle RPM value (Vrpm th) is pre-fed to the control unit (4) of the ECU (7).

[049] Further, if the ECU (7) determines that the real time throttle position value (TPS) is less than the predefined throttle position value (TPS th), then in step 006, the ECU (7) again generate the no braking application signal and the motor continues with the existing speed.

[050] Further, if the real time vehicle throttle position value (TPS) is greater than the predefined throttle position value (TPS_th), in step 007, the ECU (7) determines if the brake application signal generated and sent by the brake module (2).

[051] If the brake application signal is OFF then in step (008), again the ECU will generate the no brake application signal and the motor will continue to rotate on the same speed to retain the vehicle current speed.

[052] If the brake application signal is ON, then in step (009) the ECU (7) determines the deceleration of the vehicle using the accelerometer (6) and the logic unit for accelerator sensing (5). The ECU (7) calculates the deceleration rate value of the vehicle based on the real time vehicle speed values over an interval of time. The real time vehicle speed values are received by the ECU (7) from the vehicle speed sensor unit (3) continuously.

[053] In step 010, the ECU (7) compares the calculated deceleration rate value (DEC) with a predefined deceleration value (DEC th). The predefined deceleration value (DEC th) is pre-fed with the control module (4) of the ECU (7).

[054] If the deceleration rate value (DEC) is lesser than the predefined deceleration value (DEC_th), then in step (008) again the no brake application signal will be generated and the motor will continue to rotate on the same speed to retain the vehicle current speed. [055] Further, if the ECU (7) determines that the deceleration rate value (DEC) is greater than or equal to the predefined deceleration value (DEC_th), then in step (Oil), the true braking event is identified. Upon identification of the true braking event, the braking signal will be generated by the ECU (7) and the motor speed will be reduced gradually as required by the user. Additionally, regeneration of kinetic energy generated during the braking event is initiated to recharge the battery.

[056] While the present invention has been shown and described with reference to the foregoing preferred embodiments, it will be apparent to those skilled in the art that changes in form, connection, and detail may be made therein without departing from the spirit and scope of the invention.

Reference Numerals:

1 throttle position sensor

2 brake module

3 vehicle speed signal sensor 4 control module

5 accelerometer

7 Electronic control unit

8 inverter block 9 battery 10 motor 11 secondary logic unit