Claims:WE CLAIM:
1. A driving assist system (300) for an off-road vehicle, the system comprising:
a sensor (310) for monitoring position of a steering system of the vehicle;
an actuator (320) having a cylinder configured to move between an extended position and a retracted position depending upon position of the steering system;
a linkage mechanism assembly (500) interconnecting the cylinder with a left brake rocker (200L) and a right brake rocker (200R), the cylinder in the extended position causes the linkage mechanism assembly to operate the right brake rocker interconnected with a right brake, and in the retracted position causes the linkage mechanism assembly to operate the left brake rocker interconnected with a left brake; and
a control unit (330) configured to:
receive position information of the steering system; and
operate the actuator whereby the cylinder moves between the extended position and the retracted position depending upon the position information of the steering system to operate the linkage assembly and thereby the left brake or the right brake.

2. The driving assist system as claimed in claim 1, wherein the linkage mechanism assembly comprising:
a base plate (510);
a rod (502) rotatably mounted on the base plate and extending perpendicularly from the base plate;
a top rocker plate (520) and a bottom rocker plate (530) mounted on the rod, the top rocker plate connected with the cylinder, movement of the cylinder cause the top rocker plate and the bottom rocker plate to move; and
a LH push link (540L) and a RH push link (540R) extending from each end of the bottom plate, the LH push link coupled with the left brake rocker and the RH push link coupled with the right brake rocker, whereby movement of the bottom plate moves the LH push link or the RH push link.

3. The driving assist system as claimed in claim 1, wherein the system comprises a control unit (330) configured to:
receive position information of the steering system; and
operate the cylinder between the extended position and the retracted position depending upon the position information of the steering system.

4. The driving assist system as claimed in claim 1 or 3, wherein the cylinder is movable in plurality of extended positions and plurality of retracted positions.

5. The driving assist system as claimed in claim 1 or 4, wherein for each extended position and each retracted position the brake is applied in pre-set amounts/ratios.

6. The driving assist system as claimed in claim 1, wherein the sensor is provided adjacent to a king-pin of the steering system

7. A driving assist method for an off-road vehicle, the method comprising the steps of:
monitoring position of a steering system of the vehicle;
receiving position information of the steering system at a control unit; and
operating an actuator to actuate a linkage mechanism assembly, the linkage mechanism assembly interconnects a cylinder of the actuator with a left brake rocker and a right brake rocker, the cylinder movable between an extended position and a retracted position depending upon position information of the steering system, whereby the cylinder in an extended position causes the linkage mechanism assembly to operate the right brake rocker interconnected with a right brake, and in a retracted position causes the linkage mechanism assembly to operate the left brake rocker interconnected with a left brake, thereby applying the left brake or the right brake.
, Description:FIELD OF THE INVENTION
[001] The invention generally relates to a driving assist system and method, particularly the invention relates to the driving assist system and method for an off-road or work vehicle.

BACKGROUND OF THE INVENTION
[002] Off-road or work vehicles such as tractors are equipped with various implements to perform tasks such as plowing, tilling, harrowing, planting, etc. Certain type of fields have several rows of crops with minimal space between such rows to maximize crop yield in a given area. For tractors to turn easily from one row to other for performing various field operations, empty spaces - headland is provided at end of the agricultural field.
[003] Figure 1 shows an illustrative representation of a tractor T turning from a row R1 to an adjacent row R2. As can be seen from the figure, the tractor has to take a large turn between the rows R1 and R2. Thus, a large headland space is required to be left vacant for allowing the tractor to turn between these rows. In this regard, if such area is unavailable, the driver may have to go back and forth to turn the tractor from one row to another. Experienced and skilled drivers use braking for turning the tractor from one row to another.
[004] What is illustrated herein above by way of figure 1 is undesirable for many reasons. Firstly, the movement of the tractor will be more time consuming. Moreover, if headland space available is less, then the tractor will require more skillful maneuvering. Secondly, crops planted near the headland are likely to be damaged by the turning of tractors. This is because the crops may get trampled under the wheels of tractors or get caught in the sides of tractors.
[005] Accordingly, there is a need to address at-least the aforementioned problems.

SUMMARY OF THE INVENTION
[006] Accordingly, the present invention in one aspect provides a driving assist system for a vehicle, the system comprising a driving assist system for an off-road vehicle, the system comprising a sensor for monitoring position of a steering system of the vehicle; an actuator having a cylinder configured to move between an extended position and a retracted position depending upon position of the steering system; a linkage mechanism assembly interconnecting the cylinder with a left brake rocker and a right brake rocker, the cylinder in the extended position causes the linkage mechanism assembly to operate the right brake rocker interconnected with a right brake, and in the retracted position causes the linkage mechanism assembly to operate the left brake rocker interconnected with a left brake; and a control unit configured to: receive position information of the steering system; and operate the actuator whereby the cylinder moves between the extended position and the retracted position depending upon the position information of the steering system to operate the linkage assembly and thereby the left brake or the right brake.
[007] In another aspect, the present invention provides a driving assist method for an off-road vehicle, the method comprising the steps of monitoring position of a steering system of the vehicle; receiving position information of the steering system at a control unit; and operating an actuator to actuate a linkage mechanism assembly, the linkage mechanism assembly interconnects a cylinder of the actuator with a left brake rocker and a right brake rocker, the cylinder movable between an extended position and a retracted position depending upon position information of the steering system, whereby the cylinder in an extended position causes the linkage mechanism assembly to operate the right brake rocker interconnected with a right brake, and in a retracted position causes the linkage mechanism assembly to operate the left brake rocker interconnected with a left brake, thereby applying the left brake or the right brakes.

BRIEF DESCRIPTION OF THE DRAWINGS
[008] Reference will be made to embodiments of the invention, examples of which may be illustrated in accompanying figures. These figures are intended to be illustrative, not limiting. Although the invention is generally described in context of these embodiments, it should be understood that it is not intended to limit the scope of the invention to these particular embodiments.
Figure 1 shows an illustrative representation of a vehicle turning between rows of a field as per prior-art.
Figure 2 shows a brake rocker in accordance with an embodiment of the invention.
Figure 3 shows a block diagram of a driving assist system in accordance with an embodiment of the invention.
Figure 4 shows the driving assist system adapted to a vehicle in accordance with an embodiment of the invention.
Figure 5 shows a linkage mechanism assembly in accordance with an embodiment of the invention.
Figure 6 shows a flow diagram illustrating a driving assist method in accordance with an embodiment of the invention.
Figure 7 shows an illustrative representation comparing vehicles turning between rows of a field.

DETAILED DESCRIPTION OF THE INVENTION
[009] The present invention is directed towards a driving assist system and method for a vehicle to assist a driver with respect to turning of the vehicle such that turning radius of the vehicle is reduced.
[010] In an embodiment, the driving assist system is responsive to a turning operation of the vehicle, whereby the system monitors a steering system of the vehicle, and selectively brakes one of the wheels as per pre-set amount/ratio of braking force enabling the vehicle to turn with true rolling of the wheels. The vehicle preferably is an off-road or work vehicle such as a tractor. However, adapting the system to other types of vehicles is well within the scope of the invention.
[011] Typically, a braking system of the tractor comprises two brake pedals - a left brake pedal, and a right brake pedal. For each brake pedal, a brake rocker, and a brake linkage coupled to a brake on a respective rear wheel is provided. In this regard, each brake pedal is connected with the brake rocker which is further connected with the brake linkage of the respective brake. Accordingly, when the brake pedal is depressed/operated by the driver, the brake rocker causes the brake linkage to operate the brake.
[012] Figure 2 shows a brake rocker 200 in accordance with an embodiment of the invention. As shown, the brake rocker has a pivot sleeve 202, a side arm 204, and a bottom arm 206. The pivot sleeve enables the brake rocker to be pivotally mounted on the vehicle. The pivot sleeve 202 is mounted on a pivot pin which is welded to a bracket 210 as illustrated in the figure 4. The bracket is mounted securely on a clutch housing of a transmission. The bottom arm is connected with a brake horizontal linkage and the side arm is connected to the brake pedal of the vehicle through a brake vertical linkage, whereby upon application of force on the brake pedal, the sleeve causes the bottom arm to push the brake horizontal linkage thereby applying the brake of the vehicle. In an embodiment of the invention, the bottom arm has an extension 208 which allows the system of the present invention to be connected with the brake rocker enabling the system to control the brake. Accordingly, the brakes can be selectively operated by the driver or the system of the present invention.
[013] As discussed hereinbefore, a driver has to exercise skill to partially apply brakes (for example operate pre-set amount of brake pedal so as to partially lock the wheel) while using the left brake and/or the right brake, especially while turning the vehicle. The system of the present invention is designed to assist the vehicle/driver by controlling the application of braking force just enough to effect turning of the vehicle with true rolling and turn the vehicle around with a minimum radius without the intervention of the driver / operator. In this regard, if the vehicle is to be turned left, the system of the present invention controls the left brake by operating the brake rocker through the system whereby the left brake partially locks left wheel of the vehicle in proportion to the braking force applied, which causes the right wheel and the vehicle to swing in an arch around the partially locked left wheel which reduces turning radius of the vehicle and effect a smooth turn.
[014] Figure 3 shows a block diagram of a driving assist system 300 for a vehicle in accordance with an embodiment of the invention. The driving assist system comprises of a sensor 310, an actuator 320, a linkage mechanism assembly 500, and a control unit 330.
[015] The sensor is provided to monitor position of a steering system of the vehicle to detect wheel angle of the vehicle. In an embodiment, the sensor is provided adjacent to a king-pin of the steering system for monitoring position of the king-pin or the wheel angle. As is known, the angular position of the king-pin is dependent upon steering condition/position of the vehicle. Accordingly, as and when the vehicle is steered, the king-pin moves. The sensor is a position sensor and provides angular position information of the king-pin or the wheel angle to the control unit. Thus, the wheel angle can be detected by only one sensor, which is advantageous.
[016] The actuator is in communication with the control unit. The control unit is configured to receive position information of the wheel angle, and operate the actuator depending upon the position information of the wheel angle.
[017] Referring to figure 4 which illustrates the system adapted to a vehicle body. As shown, the actuator is adapted to the vehicle body. The actuator comprises a cylinder rod 322 and is configured to operate between an extended position and a retracted position depending upon inputs received from the sensor through the control unit. Accordingly, as the vehicle is steered, the control unit sends signal to the actuator to operate the actuator causing the cylinder rod to move between the extended position and the retracted position. In an embodiment of the invention, the cylinder rod has plurality of extended positions and plurality of retracted positions wherein each extended position or retracted position depends upon position of the wheel angle.
[018] The linkage mechanism assembly as shown in figure 4 is mounted on the vehicle adjacent to a left brake rocker 200L and a right brake rocker 200R of the vehicle. The left brake rocker and the right brake rocker is as shown in figure 2. The linkage mechanism assembly interconnects the cylinder rod with the left brake rocker and the right brake rocker. Further, the left brake rocker is connected with a left brake horizontal linkage 20L and the right brake rocker is connected with a right brake horizontal linkage 20R which lead to the left brake and the right brake respectively of the vehicle/tractor. Also, as shown in the figure, the left brake rocker is also connected with a left brake vertical linkage 22L of the vehicle and the right brake rocker is also connected with a right brake vertical linkage 22R of the vehicle which lead to the left brake pedal and the right brake pedal. In an embodiment of the invention, the actuator is interconnected with the left brake rocker and the right brake rocker via the linkage mechanism assembly. Accordingly, a single actuator operates the left brake rocker and the right brake rocker, whereby the cylinder in the extended position causes the right brake rocker to operate and the cylinder rod in the retracted position causes the left brake rocker to operate, thereby applying a right brake or a left brake in pre-determined amounts/ratios. As discussed hereinbefore, the cylinder rod has plurality of extended positions and plurality of retracted positions. Accordingly, for each extended position or retracted position the brake is applied in a pre-set amount/ratio i.e. braking force is varied depending upon position of the cylinder and/or the wheel angle.
[019] The actuator is connected to the mechanical linkage mechanism assembly via a mechanical link 10. The linkage mechanism assembly is shown in detail figure 5. The linkage mechanism assembly comprises a rod 502, a base plate 510, a top rocker plate 520, a bottom rocker plate 530, a right hand (RH) push link 540R and a left hand (LH) push link 540L. The base plate is mounted on the vehicle. The rod is rotatably mounted on the base plate whereby the rod extends perpendicularly from the base plate. The top rocker plate and the bottom rocker plate are mounted and welded to the rod. The top rocker plate is connected with the actuator such that when the cylinder is operated, the rocker plate causes the rod to rotate. The bottom rocker plate rotates as the top rocker plate is driven. As shown, the RH push link and LH push link are provided on each side of the bottom rocker plate in curvilinear slots – LH side slot 532L and RH side slot 532R, and connected with the left brake rocker and the right brake rocker, which is further connected with the left brake horizontal link and the right brake horizontal link through lock yokes leading to the left brake and the right brake. Accordingly, as the bottom rocker plate is rotated, one of the push link moves which in turn moves the respective rocker and applies the respective brake.
[020] In operation, when the vehicle is steered to the left side or right side, the steering angle is sensed by the sensor mounted on the king-pin of the front axle. The sensor sends a signal to the control unit. The control unit then sends to the signal to actuator to either retract the cylinder rod or extend the cylinder rod to actuate either the left brake or the right brake. For instance, when the vehicle is steered to the left-side, the cylinder rod moves to one of the retracted positions, which causes the top rocker plate to rotate in clock-wise direction. As the bottom rocker plate is connected to the top rocker plate through rod the bottom rocker plate rotates in clockwise direction. This clockwise rotation of the bottom rocker plate pulls the LH push link. The LH push link is interconnected with the left brake horizontal link. Hence the LH push link pulls the left brake horizontal link and subsequently left brake will be applied partially locking the left wheel of the vehicle in proportion to braking force applied. During the clockwise rotation of the bottom rocker plate the RH push link will move along in the RH side slot provided on the bottom rocker plate.
[021] When the vehicle is steered to the right-side, the cylinder rod moves to one of the extended positions, which causes the top rocker plate to rotate in anti-clockwise direction. As the bottom rocker plate is connected to the top rocker plate through rod the bottom rocker plate rotates in anti-clock wise direction. This anti clockwise rotation of the bottom rocker plate pulls the RH push link. The RH push link is interconnected with the right brake horizontal link through lock in yoke. Hence the RH push link pulls the right horizontal link and subsequently right brake will be applied partially locking the right wheel of the vehicle in proportion to braking force applied. During the anti-clockwise rotation of the bottom rocker plate the LH push link will move along in the LH side slot provided on the bottom rocker plate.
[022] In an embodiment as shown in figure 6 the present invention provides a driving assist method for an off-road vehicle. The method is carried out on the system discussed hereinbefore. The method starts by monitoring position of the steering system at step 6A. The position information of the steering system at step 6B is received at the control unit and depending upon the position information the control unit operates the actuator to actuate the linkage assembly at step 6C. As discussed hereinbefore, the linkage mechanism assembly interconnects the cylinder of the actuator with the left brake rocker and the right brake rocker, whereby the cylinder in an extended position causes the linkage mechanism assembly to operate the right brake rocker interconnected with a right brake, and in a retracted position causes the linkage mechanism assembly to operate the left brake rocker interconnected with a left brake, thereby applying a left brake or a right brake.
[023] Figure 7 shows an illustrative representation of vehicles T1 and T2 turning between rows of a field R1 and R2. Vehicle T2 comprises the driving assist system discussed hereinbefore. In this regard, the driving assist system can be retrofitted to vehicle. As can be seen in the figure, T1 has a large turning radius whereas T2 has a much smaller turning radius due to the driving assist system. In operation, as the driver intends to turn left or right, the driving assist system detects position of the steering system and steers the actuator to operate the linkage mechanism assembly. The linkage mechanism assembly depending upon position of steering system or direction of turning will operate either the left brake or the right brake. In case it is detected that the vehicle is turning left, the system of the present invention controls the left brake whereby the left brake partially locks left wheel of the vehicle in proportion to braking force applied, which causes the right wheel and the vehicle to swing in an arch around the partially locked left wheel creating a true rolling of the wheel and also reducing turning radius of the vehicle. Similarly, in case it is detected that the vehicle is turning right, the system of the present invention controls the right brake whereby the right brake partially locks right wheel of the vehicle, which causes the left wheel and the vehicle to swing in an arch around the locked right wheel creating a true rolling of the wheel and also reduces turning radius of the vehicle.
[024] While the present invention has been described with respect to certain embodiments, it will be apparent to those skilled in the art that various changes and modification may be made without departing from the scope of the invention as defined in the following claims.