A system for hill hold control in a vehicle and a method for the same

Abstract

A system (122) for hill hold control in the vehicle is disclosed. The system (122) comprises at least one hydraulic circuit (106) fluidly connecting the brake actuator (104) to brake (108) of the wheel through the master cylinder (102) and the proportionate valve (112), characterized in that, a switching valve 118 positioned between the master cylinder (102) and the proportionate valve (112). The switching valve (118) operable by a controller (120) in a closed position and an open position to hold and release the brake (108). The driver / rider usually builds up pressure for hill hold function as appropriate (user driven) and is locked by the controller (120) for the hill hold function. Post locking of pressure, driver no longer need to apply sustained force on the brake lever / pedal for the hill hold function.

Description

FORM 2THE PATENTS ACT, 1970(39 of 1970) & The Patents Rules 2003COMPLETE SPECIFICATION(SECTION 10 and Rule 13)1. Title of the invention:A SYSTEM FOR HILL HOLD CONTROL IN A VEHICLE AND A METHOD FOR THE SAME2. Applicants: a. Name: Bosch Global Software Technologies Private Limited Nationality: INDIAAddress: 123, Industrial Layout, Hosur Road, Koramangala, Bangalore - 560095, Karnataka, India b. Name: Robert Bosch GmbHNationality: GERMANYAddress: Postfach 30 02 20, 0-70442, Stuttgart, GermanyComplete Specification:The following specification describes and ascertains the nature of this invention and the manner in which it is to be performed.Field of the invention:

[0001] The present invention relates to a system for hill hold control in a vehicle and a method for the same.Background of the invention:

[0002] According to a prior art WO2014044147, method, system, and vehicle for implementing hill hold control based on ABS is disclosed. Provided are a method, a system and a vehicle for implementing hill hold control based on ABS, wherein the method comprises the steps of: providing a check valve having a return spring in the ABS; keeping an inlet valve and an outlet valve being closed and by means of a force of the return spring of the check valve, maintaining a pressure of a wheel cylinder under a target pressure to keep the vehicle stopped on a slope within a preset period of time, when it is determined that the vehicle has been braked and stopped on the slope and a brake pedal has been fully released; and opening the outlet valve so that the pressure of the wheel cylinder is reduced to zero, when it is determined that a accelerator pedal has been pushed and a current driving torque is greater than a rolling torque on the slope. This method achieves HHC function in a vehicle equipped merely with ABS. It is not only easy to be implemented, but also reliable to operate with high efficiency and helpful to enhance a comfort and safety for driving.Brief description of the accompanying drawings:

[0003] An embodiment of the disclosure is described with reference to the following accompanying drawings,

[0004] Fig. 1 illustrates a block diagram of a system for hill hold control in a vehicle, according to an embodiment of the present invention, and

[0005] Fig. 2 illustrates a flow diagram of a method for facilitating hill hold control in the vehicle, according to the present invention.Detailed description of the embodiments:

[0006] Fig. 1 illustrates a block diagram of a system for hill hold control in a vehicle, according to an embodiment of the present invention. In Fig. 1 two systems are shown. A conventional setup 100 shows the hill hold control with as known in the art. A system 122 shows the hill hold control with new design or setup. The conventional setup 100 comprises two channels for a two-wheeler vehicle. One channel is for hand brake and other channel is for foot brake, however only one is take for explanation throughout this disclosure. The conventional setup 100 comprises a hydraulic circuit 106 (or brake circuit) fluidly connecting / coupling a brake actuator 104, i.e. brake lever or brake pedal, to a brake 108 of a wheel 110. The brake 108 is either a drum brake or disc brake. The hydraulic circuit 106 comprises a master cylinder 102 which carries the brake fluid and a proportionate valve 112 which in turn is connected to the brake 108 comprising the calipers and brake pads. The proportionate valve 112 is connected with a check valve 114 in parallel. Thus, in case of braking on a slope the proportionate valve 112 offers restricted flow and the check valve 114 also restricts to the flow back to the master cylinder 102. However, the check valve 114 being mechanical valve is designed to restrict flow only few seconds / bars and then the fluid starts flowing back thereafter causing improper hill hold control and only for very short duration. The other components of the hydraulic circuit 106 such as the motor 116 which is connected to the pump of bot channels, accumulator, filters, etc., are not described as being state of the art.

[0007] According to an embodiment of the present invention, the system 122 for hill hold control in the vehicle is disclosed. The system 122 comprises at least one hydraulic circuit 106 fluidly connecting the brake actuator 104 to brake(s) 108 of the wheel 110 through the master cylinder 102 and the proportionate valve 112, characterized in that, a switching valve 118 positioned between the master cylinder 102 and the proportionate valve 112. The switching valve 118 operable by a controller 120 in a closed position and an open position to hold and release the brakes 108. The valves are provide in a hydraulic unit, and the hydraulic unit is connected to the master cylinder 102, brakes 108, accumulator and the like.

[0008] According to an embodiment of the present invention, the fluid pressure build up in the hydraulic circuit 106 for braking is translated through manual depressing of the brake actuator 104. The brake actuator 104 is at least one of the brake lever and the brake pedal.

[0009] According to an embodiment of the present invention, the controller 120 sets the switching valve 118 to the closed position once the brake actuator 104 is depressed to stop the vehicle and released thereafter on a slope. The slope is either an uphill (or positive slope) or downhill (negative slope). The inclination of the vehicle on the surface or road is detected either by an inclinometer connected to the controller 120 or a button in the vehicle which if pressed confirms the presence of the slope. Further, the controller 120 sets the switching valve 118 to the open position when a cancel request is detected. The cancel request is based on input from at least one selected from a condition comprising a drive-off, hold-limit, forcerelease, and deactivation.

[0010] According to an embodiment of the present invention, the hydraulic circuit 106 is part of an Anti-Lock Braking System (ABS). Alternatively, the hydraulic unit of the ABS is used for the enablement of the present invention. According to the present invention, the vehicle is selected from a group comprising the twowheeler, a three-wheeler, a four-wheeler, and multi- wheeler.

[0011] According to the present invention, the controller 120 is refers to computing devices / units comprising components such as memory element such as Random Access Memory (RAM) and / or Read Only Memory (ROM), Analog-to-Digital Converter (ADC), Digital-to-Analog Convertor (DAC), clocks, timers, and a processor (such as Central Processing Unit (CPU)) (capable of implementing machine learning) connected with each other and to other components through communication bus channels in a Printed Circuit Board (PCB). The components mentioned are just for understanding and may have more or less components as perrequirement. The memory element is prestored with map, table, model, modules, logics, instructions, programs, applications, threshold deviation, or values, which is accessed by the at least one processor as per the defined routines. The internal components of the controller 120 are not explained for being state of the art, and the same must not be understood in a limiting manner. The controller 120 is capable to communicate through wired and wireless means such as but not limited to Global System for Mobile Communications (GSM), 3G, 4G, 5G, Wi-Fi, Bluetooth, Ethernet, serial networks, Universal Serial Bus (USB) cable, micro-USB, and the like.

[0012] Further, the processor may be implemented as any or a combination of one or more microchips or integrated circuits interconnected using a parent board, hardwired logic, software stored in the memory element and executed by a microprocessor, firmware, an application specific integrated circuit (ASIC), and / or a field programmable gate array (FPGA). The processor is configured to exchange and manage the processing of various Artificial Intelligence (Al) modules.

[0013] According to the present invention, a working of the system 122 is explained. Consider the two- wheeler vehicle equipped / installed with the second system 122 and is being driven on a road. When the slope is reached and the driver / rider intends to stop on the slope (such as incline), the brake actuators 104 are pressed. The controller 120 has already received the inclined road situation from the inclinometer or a specific button in the vehicle which is manually pressed by the driver / rider. Once the brake actuators 104 are pressed, the brake fluid in the hydraulic circuit 106 are pressurized which applies force on the brakes 108 and the vehicle stops on the slope. The controller 120 sets the switching valve 118 to closed position thereby completely restricting the backflow of the brake fluid even though the proportionate valve 112 is not closed. Now, when the brake actuators 104 are released, the vehicle still stands in braking condition without any effort from the driver / rider. The pressure generated by the manual depressing of the brake actuator 104 is used and not the active pressure build-up by pumps.

[0014] When the driver / rider intends to proceed, the accelerator or throttle is increased and the controller 120 sets the switching valve 118 to open position, thereby allowing the brake fluid to stabilize to normal / regular pressure. Any other vehicle signal / condition to cancel the hill hold control is also possible to be used.

[0015] According to an embodiment of the present invention, the system 122 for hill hold control in the vehicle is disclosed. The system 122 comprises at least one hydraulic circuit 106 fluidly connecting the brake actuator 104 to brake 108 of the wheel through the master cylinder 102 and the proportionate valve 112, and the switching valve 118 positioned between the master cylinder 102 and the proportionate valve 112, characterized in that, the switching valve 118 operable by the controller 120 in the closed position and the open position to hold and release the brakes 108 without active pressure build-up. The fluid pressure is build solely by the manual depressing of the brake actuator 104.

[0016] According to an embodiment of the present invention, the system 122 for hill hold control in the vehicle is disclosed. The system 122 comprises at least one hydraulic circuit 106 fluidly connecting the brake actuator 104 to brakes 108 of the wheel through the master cylinder 102 and the proportionate valve 112, the switching valve 118 positioned between the master cylinder 102 and the proportionate valve 112, characterized in that, the proportionate valve 112 is replaced by the switching valve 118 which is operable by the controller 120 in the closed position and the open position to hold and release the brakes 108. The fluid pressure is generated solely by the manual depressing of the brake actuator 104.

[0017] The present invention is explained with single channel only as an example, where there is a passive (not active) pressure build up in the hydraulic unit, and is applicable to any number of channels. The hill hold control function is offered in pumpless manner using the switching valve 118 in the hydraulic unit. The presentinvention also holds good for passenger cars (and other types of vehicles mentioned below) installed with or without ABS units.

[0018] Also, the valve combination of switching valve 118 and the proportionate valve 112 together offer failsafe safety concept for quick return of brake fluid from wheel brake caliper to main cylinder / reservoir when driver releases brake lever / pedal for ABS / Normal braking functional safety requirements on the vehicle.

[0019] Fig. 2 illustrates a flow diagram of a method for facilitating hill hold control in the vehicle, according to the present invention. The vehicle comprises at least one hydraulic circuit 106 fluidly connecting the brake actuator 104 to brakes 108 of the wheel through the master cylinder 102 and the proportionate valve 112. The method is characterized by plurality of steps of which a step 202 comprises closing the switching valve 118 positioned between the master cylinder 102 and the proportionate valve 112 on detecting the braking operation on the slope. A step 204 comprises opening the switching valve 118 after receiving cancel request for the brakes 108.

[0020] According to the method, the cancel requests is at least one selected from the condition comprising the drive-off, hold-limit, force-release, and deactivation. Also, the method comprises pressure build up in the hydraulic circuit 106 for applying the brakes 108. The pressure build-up is due to the force received from manual depressing of the brake actuator 104. The brake actuator 104 is at least one of the brake lever and the brake pedal. The hydraulic circuit 106 is part of the Anti- Lock Braking System (ABS) and pressure build-up is by the manual press of brake actuator 104 and is held at the increased pressure by the switching valve 118 in closed position.

[0021] According to the present invention, the vehicle is selected from the group comprising the two-wheeler, the three-wheeler, the four-wheeler, and multiwheeler.

[0022] According to the present invention, the Normally Open (NO) switching valve 118 (or any other type) offers the pumpless hill hold function. The driver / rider presses brake lever / pedal and builds up the pressure at standstill and the switching valve 118 is closed to hold the pressure in the hydraulic circuit 106 for the brake 108. The “intention to brake” for hill hold control / function is usually sensed by the controller 120 via the pressure sensor in the hydraulic unit containing the valves. The “intention to brake” is also possible by using signal from stop / brake lamp instead of the pressure sensor. The Stop / Brake lamp switch signal in the vehicle is used as input to the controller 120 and to sense the driver intent, and absolute pressure measurement is not needed. The driver / rider usually builds up pressure for hill hold function as appropriate (user driven) and is locked by the controller 120 for the hill hold function. Post locking of pressure, driver no longer need to apply sustained force on the brake lever / pedal for the hill hold function. The present invention provides a solution using of the switching valve 118 in the Hydraulic Unit and with or without active pressure build up in the configuration for ABS or independently to fulfill / offer the pumpless vehicle / hill hold function. The use of the brake lamp switch signal (available in two, three, four wheelers, etc.,) and the elimination of the pressure sensor further results in extremely low cost option for the hill hold control functions.

[0023] According to the present invention, a pumpless method / system for vehicle / hill hold control / function with or without ABS in automotive vehicles is disclosed. The driver / rider does not have to hold the brake actuator 104 after the lock in of pressure has happened. The brake pressure is released by opening the switching valve 118 triggered by any of the following conditions and not limited to these only. The driver can also indicate intention to start by cadencing the brake channel pedal / lever an alternate time to stop / release the hill hold control function. The conditions comprises drive-off, hold-limit is over, force-release and deactivation. In hold-limit, when the driver does not input brake some time, thebrakes are released. In force-release, the hill hold control is released by side stand or gear neutral.

[0024] It should be understood that the embodiments explained in the description above are only illustrative and do not limit the scope of this invention. Many such embodiments and other modifications and changes in the embodiment explained in the description are envisaged. The scope of the invention is only limited by the scope of the claims.

Claims

We Claim:

1. A system (122) for hill hold control in a vehicle, said system (122) comprises at least one hydraulic circuit (106) fluidly connecting a brake actuator (104) to brakes (108) of a wheel (110) through a master cylinder (102) and a proportionate valve (112), characterized in that, a switching valve (118) positioned between said master cylinder (102) and said proportionate valve (112), said switching valve (118) operable by a controller (120) in a closed position and an open position to hold and release said brakes (108).

2. The system (122) as claimed in claim 1, wherein fluid pressure build up in said hydraulic circuit (106) for braking is translated through manual depressing of said brake actuator (104), wherein said brake actuator (104) is at least one of a brake lever and a brake pedal.

3. The system (122) as claimed in claim 1, wherein said controller (120) sets said switching valve (118) to said closed position once said brake actuator (104) is depressed to stop said vehicle and released thereafter.

4. The system (122) as claimed in claim 1, wherein said controller (120) sets said switching valve (118) to said open position when a cancel request is detected, wherein said cancel requests is at least one selected from a condition comprising a drive-off, hold-limit, force-release, and deactivation.

5. The system (122) as claimed in claim 1, wherein hydraulic circuit (106) is part of an Anti-Lock Braking System (ABS).

6. A method for operating hill hold control in a vehicle, said vehicle comprises at least one hydraulic circuit (106) fluidly connecting a brake actuator (104) to brake (108) of a wheel (110) through a master cylinder (102) and a proportionate valve (112), characterized by,closing a switching valve (118) positioned between said master cylinder (102) and said proportionate valve (112), on detecting a braking operation on a slope, and opening said switching valve (118) after receiving cancel request for said brake (108).

7. The method as claimed in claim 6, wherein said cancel requests is at least one selected from a condition comprising a drive-off, hold-limit, forcerelease, and deactivation.

8. The method as claimed in claim 6 comprises pressure build up in said hydraulic circuit (106) for braking, said pressure build-up is due to force received from manual depressing of said brake actuator (104), wherein said brake actuator (104) is at least one of a brake lever and a brake pedal.

9. The method as claimed in claim 6, wherein hydraulic circuit (106) is part of an Anti-Lock Braking System (ABS).

10. The method as claimed in claim 6, wherein said vehicle is selected from a group comprising a two-wheeler, a three-wheeler, a four-wheeler, and multi-wheeler.Dated 28 August 2024 (Digitally signed)Siddharth Karkhanis (IN / PA- 1195) On-behalf of the Applicants

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