Description:TECHNICAL FIELD
[001] The embodiments herein generally relate to braking system in vehicles and more particularly, to a selective braking system for an agricultural vehicle such as a tractor.
BACKGROUND
[002] Generally, tractors have two brake pedals viz. a left side brake pedal and a right side brake pedal, for respective left rear-wheel and right rear-wheel drive. The brake pedals are locked together for smoother braking when the tractor is being used on the road or for transportation. A locking mechanism such as a locking bracket or a locking bolt is used for locking the brake pedals together. When the brake pedals are locked together, the braking system operates in a regular mode, wherein the brake pedals are pressed together by the user.
[003] The two brake pedals of the tractor can be separately operated for field or yard work where sharp, nimble turning is necessary. This feature of the braking system in tractors which allows the left side brake and the right side brake to be operated separately and independent of each other, is commonly referred to as single side braking system or split braking system. This system is often used in agricultural and construction vehicles to assist in making sharp turns, especially while working in confined spaces or when precision in movement is required. The single side braking system allows braking on one side and allowing the other side to rotate freely, which allows the tractor to pivot around the braked wheels, thereby reducing the turning radius. Further, the tractor can make sharper turns when one side brake is operated than it would if both sides were braking simultaneously.
[004] In some tractors, the single side braking system is automated for headland turning. A separate hydraulic braking assembly is provided along with the traditional mechanical braking assembly, wherein the hydraulic braking assembly is actuated to allow automatic actuation of the left side brake and the right side brake to enable headland turning. The hydraulic braking assembly works independently of the mechanical braking assembly and is activated when the automatic single side braking system is activated.
[005] Further, the tractors with automatic single side braking system are usually used in large fields where the gap between two rows of vegetation is considerable, providing substantial area for the tractor to navigate a headland turn. In contrast to agricultural fields, in vineyards, a tractor needs to be driven across permanent structure of narrow rows with vegetation. The preferable driving pattern for the tractor to navigate a turn is to skip a row to minimize the travel path. To cover the rows in the vineyard without damaging the vegetation, the tractor has to navigate a pi (p) shape head turn, which becomes difficult for a tractor designed for operating in the fields. Due to these constraints, a tractor with the conventional automatic single side braking system cannot be easily deployed in a vineyard. Furthermore, most of the tractors used in vineyard are small or medium sized tractors with lower horsepower. Using the conventional automatic single side braking system, which usually have high cost, in such type of tractors would increase the overall cost of the tractor, thereby diminishing the tractors’ economic viability. Also, the existing single side braking systems require factory fitment, making it difficult to retrofit the system in an operational tractor.
[006] Therefore, there exists a need for a single side braking system for a vehicle which obviates the aforementioned drawbacks.
OBJECTS
[007] The principal object of embodiments herein is to provide a selective braking system for an agricultural vehicle.
[008] Another object of embodiments herein is to provide the selective braking system which is configured to facilitate automatic and selective braking of a left side brake and a right side brake of the agricultural vehicle to facilitate headland turning of the vehicle during field work.
[009] Another object of embodiments herein is to provide the selective braking system for the agricultural vehicle which facilitates automatic selective braking to allow the vehicle to navigate between narrow and constricted areas such as between rows of vegetation in a vineyard.
[0010] Another object of embodiments herein is to provide the selective braking system for an agricultural vehicle which is retrofittable, inexpensive and compact.
[0011] These and other objects of embodiments herein will be better appreciated and understood when considered in conjunction with following description and accompanying drawings. It should be understood, however, that the following descriptions, while indicating embodiments 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 DRAWINGS
[0012] The embodiments are illustrated in the accompanying drawings, throughout which like reference letters indicate corresponding parts in various figures. The embodiments herein will be better understood from the following description with reference to the drawings, in which:
[0013] Fig. 1 depicts a perspective view of a selective braking system, according to embodiments as disclosed herein;
[0014] Fig. 2 is another perspective view of the selective braking system, according to embodiments as disclosed herein;
[0015] Fig. 3A is a top view of a brake actuator of the selective braking system, according to embodiments as disclosed herein,
[0016] Fig. 3B is a cross sectional view of the brake actuator assembly, according to embodiments as disclosed herein; and
[0017] Fig. 4 is a flow chart depicting a logic of operation of the selective braking system, according to embodiments as disclosed herein.

DETAILED DESCRIPTION
[0018] 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.
[0019] The embodiments herein achieve a selective braking system for an agricultural vehicle which is configured to facilitate automatic and selective braking of a left side brake and a right side brake of the agricultural vehicle to facilitate headland turning of the vehicle during field work. Further, embodiments herein achieve the selective braking system for the agricultural vehicle which facilitates ease in navigating narrow and constricted areas, is retrofittable, inexpensive, and compact. Referring now to the drawings Figs. 1 through 4, where similar reference characters denote corresponding features consistently throughout the figures, there are shown embodiments.
[0020] Fig. 1 and Fig. 2 are perspective views of a selective braking system (100) for an agricultural vehicle, according to embodiments as disclosed herein. The selective braking system (100) includes a left brake actuator (102) connected in line with a left brake linkage (200L) of the vehicle, and a right brake actuator (102R) connected in line with a right brake linkage (200R) of the vehicle. The left brake actuator (102L) and the left brake linkage (200L) have a common braking movement path, and the right brake actuator (102R) and the right brake linkage (200R) have another common braking movement path. The selective braking system (100) is configured to be operated in a mechanical mode and an automatic mode. In the mechanical mode, a left brake and a right brake of the vehicle is manually actuated by a user by pressing a respective left brake pedal (202L) and right brake pedal (202R) of the vehicle. In the automatic mode, the left brake and right brake are selectively and automatically actuated when the user selects the automatic mode of operation of the selective braking system (100). The selective braking system (100) is configured to allow a mechanical movement of the respective brake linkage (200L, 200R) when the respective brake pedal (202L, 202R) is operated by the user in the mechanical mode of operation. Further, in the automatic mode of operation, the selective braking system (100) is configured to selectively actuate the left brake actuator (102L) and the right brake actuator (102R) to operate the respective left brake and right brake by displacing the corresponding brake linkage (200L, 200R). In an embodiment, a selective braking switch is provided in the vehicle, wherein the selective braking switch is operated to an ON position when a user wants to operate the braking system in the automatic mode of operation. For the purpose of this description and ease of understanding, the selective braking system (100) is explained herein with below reference to an agricultural vehicle such as a tractor. However, it is also within the scope of the invention to use/practice the components of the selective braking system (100) for any other vehicle which has a split braking mechanism, without otherwise deterring from the intended function of the selective braking system (100) as can be deduced from the description and corresponding drawings.
[0021] Each of the left brake actuator (102L) and the right brake actuator (102R) are connected between a brake connecting shaft (204) of the vehicle and the respective brake linkage (200L, 200R). Further, each of the left brake actuator (102L) and the right brake actuator (102R) includes an actuating mechanism (104L, 104R), a top end member (106L, 106R) connected towards a first end of the actuating mechanism (104L, 104R), and a bottom end member (108L ,108R) connected between a second end of the actuating mechanism (104L ,104R) and the respective brake linkage (200L, 200R). In an embodiment, the bottom end member (108L, 108R) is connected with the corresponding brake linkage (200L, 200R) through a connector (108C). The actuating mechanism (104L, 104R) is configured to facilitate movement of the respective brake linkage (200L, 200R) upon actuation. The top end member (106L ,106R) of the brake actuator (102L, 102R) is adapted to have a forward movement to allow movement of the respective brake linkage (200L, 200R) when the respective brake pedal (200L, 200R) is operated in the mechanical mode of operation. Further, the top end member (106L, 106R) is adapted to be locked in an initial position to prevent the forward movement of the top end member (106L, 106R) with respect to the actuating mechanism (104L, 104R) and to facilitate displacement of the respective brake linkage (200L, 200R), when the respective brake actuator (102L, 102R) is actuated in the automatic mode of operation. The selective braking system (100) further includes a stopper member (110) which is configured to lock the top end member (106L, 106R) when the selective braking system (100) is operating in the automatic mode. The stopper member (110) is configured to release the top end member (106L, 106R) from the initial position to allow the forward movement of the top end member (106L, 106R) when the brake pedal (202L, 202R) is pressed by a user in the mechanical mode of operation of the selective braking system (100). For the purpose of this description and ease of understanding, the actuating mechanism (104L, 104R) is considered to be a hydraulic mechanism. However, it is within the scope of this invention to have any other mechanism such as, but not limited to, a pneumatic mechanism, an electromechanical linear actuator, and an electric motor driven linear actuator, without otherwise deterring from the intended function of the actuating mechanism, as can be deduced from the description.
[0022] In an embodiment, as shown in Figs. 3A and 3B, the top end member (106L, 106R) is connected to a cylinder head (104H) of the hydraulic actuating mechanism (104L, 104R). The bottom end member (108L, 108R) is connected to a piston seal (104S) of the hydraulic actuating mechanism (104L ,104R). The hydraulic actuating mechanism (104L,104R) is adapted to receive a fluid when the respective brake actuator (102L, 102R) is actuated in the automatic mode of operation. When the hydraulic actuating mechanism (104L, 104R) receives the fluid, the piston head (104H) moves forward. Since the top end member (106L, 106R) is locked in the initial position, the forward movement of the piston head (104H) causes the bottom end member (108L, 108R) to move forward, thereby resulting in a forward displacement of the respective brake linkage (200L, 200R).
[0023] The selective braking system (100) further includes a sensing unit, and a controller unit provided in communication with the sensing unit. The sensing unit is configured to sense a wheel angle of a right wheel and a left wheel of the vehicle, detect whether the right brake pedal (202R) and the left brake pedal (202L) are connected via a latch bracket, and send corresponding output signals to the controller unit. The sensing unit includes a wheel angle sensor, and a latch sensor. The wheel angle sensor is configured to sense the wheel angle of the right wheel and the left wheel to detect a right turn and a left turn of the vehicle. In an embodiment, the wheel angle sensor is mounted on a kingpin axis of the vehicle. The latch sensor is configured to detect the position of a latch bracket to determine whether the left brake pedal (202L) and the right brake pedal (202R) are connected via the latch bracket.
[0024] Fig. 4 is a flowchart depicting the logic of operation of the selective braking system. The controller unit is configured to check whether the selective braking switch is ON. On detecting that the selective braking switch is ON, the controller unit is configured to check whether the latch bracket is disconnected based on the corresponding output signal received from the latch bracket sensor. On detecting that the latch bracket is disconnected, the controller unit is configured to check whether the wheel angle of the right wheel and the wheel angle of the left wheel is respectively above a right wheel angle threshold TR and a left wheel angle threshold TL. The value of the wheel angle enables in determining whether the vehicle is navigating a turn. If the controller unit detects the right wheel angle is greater than the right wheel angle threshold TR, the controller unit is configured to actuate the right brake actuator (102R), thereby operating the right brake of the vehicle. If the controller unit detects that the left wheel angle is greater than the left wheel angle threshold TL, the controller unit is configured to actuate the left brake actuator (102L), thereby operating the left brake of the vehicle.
[0025] The controller unit is further configured to check whether the right wheel angle is increasing at a predetermined value Ti, to determine whether the vehicle is still navigating the turn or the turn has been completed. On detecting that the right wheel angle is above the right angle threshold TR and the right wheel angle is increasing at the predetermined value Ti, the controller unit is configured to continue actuation of the right brake actuator (102R). The controller unit is further configured to check whether the right wheel angle is decreasing at the predetermined value Ti and discontinue actuation of the right brake actuator (102R) on detecting that the right wheel angle is decreasing at the predetermined value Ti. Similarly, the controller unit is configured to check whether the left wheel angle is increasing at the predetermined value Ti on detecting that left wheel angle is above the left angle threshold TL, and continue actuation of the left brake actuator (102L) on detecting the left wheel angle is increasing at the predetermined value Ti. Further, the controller is configured to discontinue actuation of the left brake actuator (102L) on detecting the left wheel angle is decreasing at the predetermined value Ti. In an embodiment, the value of the right angle threshold TR is between 20 degrees to 40 degrees, value of the left angle threshold TL is between 15 degrees to 35 degrees, and the predetermined angle value Ti is between 3 degrees to 10 degrees. This logic of operation of the selective braking system (100) ensures Pi shape headland turning as it allows the vehicle to pivot for some time by actuating the brake at the side of turning and releases the brake once steering tries to make straight line, and again actuates the brake when the vehicle navigates turning in the opposite side.
[0026] The selective braking system (100) further includes a flow control unit (300) provided in communication with the controller unit and the actuating mechanism (104L, 104R) of each of the left brake actuator (102L) and the right brake actuator (102R). The flow control unit (300) is configured to receive the fluid from a hydrostatic unit (302) of the vehicle, selectively direct the fluid to the actuating mechanism (104L, 104R) via a respective pressure line (304L, 304R) based on the input received from the controller unit. In an embodiment, the hydraulic actuating mechanism (104L, 104R) includes an inlet to receive the fluid from the respective pressure line (304L, 304R). The flow control unit (300) is further configured to direct the fluid received back from the hydraulic actuating mechanism (104L, 104R) to a transmission unit (306) of the vehicle. The flow control unit (300) includes a direction control valve (300V) which is configured to be actuated by the controller unit to allow the flow of fluid to actuating mechanism (104L, 104R) of any one of the left brake actuator (102L) and right brake actuator (102R). In an embodiment, the direction control valve (300V) is a solenoid valve.
[0027] The technical advantages of the selective braking system (100) for an agricultural vehicle are as follows. Auto engagement disengagement of selective braking, no major change in existing brake system, logic followed to maintain pi shape headland turn to fulfill the requirement in vineyard, add on kit as replacement to existing brake linkage sold vehicle, integration of actuating mechanism with brake linkage, low cost operator assist which encourages non skill labor to perform farm operations without damage to any crops/ structures, and enables autonomous navigation for tight headland turn.
[0028] 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, those skilled in the art will recognize that the embodiments herein can be practiced with modifications within the spirit and scope of the embodiments as described herein.
, Claims:We claim:
1. A selective braking system (100) for a vehicle, said braking system (100) comprising:
a left brake actuator (102L) and a right brake actuator (102L) connected respectively in line with a left brake linkage (200L) and a right brake linkage (200R) of the vehicle;
wherein,
said braking system (100) is configured to:
allow a mechanical movement of the respective brake linkage (200L, 200R) when a respective brake pedal (202L ,202R) is operated by a user, in a mechanical mode of operation; and
selectively actuate said left brake actuator (102L) and said right brake actuator (102R) to operate a respective left brake and right brake of the vehicle by moving/displacing the corresponding brake linkage (104L ,104R), in an automatic mode of operation.
2. The braking system (100) as claimed in claim 1, wherein,
said left brake actuator (102L) and said right brake actuator (102R) are connected between a brake connecting shaft (204) and the respective brake linkage (200L, 200R);
said left brake actuator (102L) and left brake linkage (200L) have a common braking movement path; and
said right brake actuator (102R) and the right brake linkage (200R) have another common braking movement path.
3. The braking system (100) as claimed in claim 2, wherein each of said left brake actuator (102L) and said right brake actuator (102R) comprises:
an actuating mechanism (104L, 104R) configured to facilitate movement of the respective brake linkage (102L, 102R) upon actuation;
a top end member (106L, 106R) connected towards a first end of said actuating mechanism (104L, 104R); and
a bottom end member (108L, 108R) connected towards a second end of said actuating mechanism (104L, 104R) and connected with a respective brake linkage (200L, 200R).
4. The braking system (100) as claimed in claim 3, wherein said top end member (106L, 106R) is adapted to:
have a forward movement, thereby allowing movement of the respective brake linkage (200L, 200R) when the respective brake pedal (202R, 202L) is operated in the mechanical mode of operation; and
to be locked to prevent the forward movement of said top end member (106L, 106R) with respect to said actuating mechanism (104L, 104R), thereby facilitating displacement of the respective brake linkage (102L, 102R), when said actuation mechanism (104L, 104R) of said respective brake actuator (102L ,102R) is actuated in the automatic mode of operation.
5. The braking system (100) as claimed in claim 4, wherein said braking system (100) includes a stopper member (110), wherein said stopper member (110) is configured to:
lock said top end member (106L, 106R) when said braking system (100) is operating in the automatic mode, and
release said top end member (106L, 106R) to allow the forward movement of said top end member (106L, 106R) when the brake pedal (202) is pressed by a user in a mechanical mode of operation of said braking system (100).
6. The braking system (100) as claimed in claim 1, wherein said braking system (100) comprises:
a sensing unit; and
a controller unit provided in communication with said sensing unit,
wherein,
said sensing unit is configured to:
sense a wheel angle of a right wheel and a left wheel of the vehicle;
detect whether the right brake pedal (202R) and the left brake pedal (202L) are connected via a latch bracket (202B); and
send corresponding output signals to said controller unit; and
said controller unit is configured to:
check whether a selective braking switch is on, wherein said selective braking switch is operated to an ON position when a user wants to operate said braking system (100) in the automatic mode of operation;
on detecting that the selective braking switch is ON, check whether the latch bracket (202B) is disconnected;
on detecting that the latch bracket (202B) is disconnected, check whether the wheel angle of the right wheel and the left wheel is respectively above a right wheel angle threshold TR and a left wheel angle threshold TL;
actuate said right brake actuator (102R) on detecting the right wheel angle to be greater than the right wheel angle threshold TR, thereby operating the right brake of the vehicle; and
actuate said left brake actuator (102L) on detecting the left wheel angle to be greater than the left wheel angle threshold value TL, thereby operating the left brake of the vehicle.
7. The braking system (100) as claimed in claim 6, wherein said controller unit is configured to:
check whether the right wheel angle is increasing at a predetermined value Ti on detecting that the right wheel angle is above the right angle threshold TR;
continue actuation of said right brake actuator (102R) on detecting the right wheel angle to be increasing at the predetermined value Ti;
check whether the right wheel angle is decreasing at the predetermined value Ti;
discontinue actuation of said right brake actuator (102R) on detecting the right wheel angle decreasing at the predetermined value Ti;
check whether the left wheel angle is increasing at the predetermined value Ti on detecting the left wheel angle is above the left angle threshold TL;
continue actuation of said left brake actuator (102L) on detecting the left wheel angle is increasing at the predetermined value Ti;
check whether the left wheel angle is decreasing at the predetermined value Ti; and
discontinue actuation of said left brake actuator (102L) on detecting the left wheel angle decreasing at the predetermined value Ti.
8. The braking system (100) as claimed in claim 6, wherein said sensing unit comprises:
a wheel angle sensor configured to sense the wheel angle of the right wheel and the left wheel to detect a right turn and a left turn of the vehicle, said wheel angle sensor adapted to be mounted on a kingpin axis of the vehicle; and
a latch sensor configured to detect whether the latch bracket (202B) is connecting the left brake pedal (202L) and the right brake pedal (202R).
9. The braking system (100) as claimed in claim 6, wherein said actuating mechanism (104L, 104R) comprises a hydraulic mechanism, wherein,
said top end member (106L, 106R) is connected to a cylinder head (104H) of the hydraulic mechanism;
said bottom end member (108L, 108R) is connected to a piston seal (104S) attached to a piston (104P) of the hydraulic mechanism;
said hydraulic mechanism is adapted to receive a fluid when said respective brake actuator (102L, 102R) is actuated in the automatic mode of operation, causing a forward movement of the piston (104P) of the hydraulic mechanism, thereby resulting in a forward displacement of the respective brake linkage (200L, 200R).
10. The braking system (100) as claimed in claim 9, wherein said braking system (100) comprises:
a flow control unit (300) provided in communication with said controller unit and said actuating mechanism (104L, 104R) of each of said left brake actuator (102L) and right brake actuator (102R),
wherein,
said flow control unit (300) is configured to:
receive the fluid from a hydrostatic unit (302) of the vehicle;
selectively direct the fluid to said actuating mechanism (104L, 104R) via a respective pressure line (304L, 304R), based on an input received from said controller unit; and
direct the fluid received back from said actuating mechanism (104L, 104R) to a transmission unit (306) of the vehicle.
11. The braking system (100) as claimed in claim 9, wherein said flow control unit (300) includes a direction control valve (300V), wherein said direction control valve (300V) is configured to be actuated by said controller unit to allow the flow of fluid to said actuating mechanism (104L, 104R) of any one of said left brake actuator (102L) and said right brake actuator (102R).
12. The braking system (100) as claimed in claim 8, wherein said direction control valve (300V) is a solenoid valve.
13. The braking system (100) as claimed in claim 6, wherein a value of the right-angle threshold TR is between 20 degrees to 40 degrees, a value of the left angle threshold TL is between 15 degrees to 35 degrees, and the predetermined angle value Ti is between 3 degrees to 10 degrees.
14. The braking system (100) as claimed in claim 3, wherein said bottom end member (108L, 108R) is connected with the corresponding brake linkage (200L, 200R) through a connector (108C).