WO2021005406A1

WO2021005406A1 - A headland turning system for an agricultural machine

Info

Publication number: WO2021005406A1
Application number: PCT/IB2019/056951
Authority: WO
Inventors: Aravind Bharadwaj; Sreegururaj JAYACHANDER; Manikarthi SUBRAMANI; Anand Kishore; Jagadish GUNNAM; Keshav SHAHI
Original assignee: Mahindra And Mahindra Limited
Priority date: 2019-07-08
Filing date: 2019-08-16
Publication date: 2021-01-14

Abstract

The present disclosure relates to the field of control systems for agricultural machinery and discloses a headland turning system (100) for an agricultural machine. The system (100) comprises navigation unit (102), a steering angle sensor (104), a steering controller (108), and a braking controller (110). The navigation unit (102) generates guidance commands for steering and braking of the agricultural machine based on radio signals received from a satellite constellation, a correction data and an attitude data. The steering angle sensor (104) periodically measures steering angle of a steering wheel (710) of the agricultural machine. The steering controller (108) generates a steering control signal for actuating a steering actuator based on the steering guidance commands and measured steering angle. The braking controller (110) generates a braking control signal for actuating a brake actuator (112) of the agricultural machine based on the braking guidance commands to reduce headland space wastage during turning.

Description

A HEADLAND TURNING SYSTEM FOR AN AGRICULTURAL MACHINE

FIELD

The present disclosure relates to the field of agricultural machinery. More particularly, the present disclosure relates to a headland turning system for an agricultural machine. DEFINITIONS

As used in the present disclosure, the following terms are generally intended to have the meaning as set forth below, except to the extent that the context in which they are used indicate otherwise.

Headland - The term‘headland’ hereinafter refers to a strip of land along the edge of an arable field left unploughed to allow space for machines.

Steering angle - The term‘steering angle’ hereinafter refers to an angle relative to a center position from which a steering wheel is rotated.

Satellite constellation - The term‘satellite constellation’ hereinafter refers to a group of coordinated satellites that are synchronized to orbit the earth for providing navigation signals to the users.

Inertial measurement unit - The term‘inertial measurement unit’ hereinafter refers to a self-contained system or an electronic device that measures and reports a body's specific force, angular rate, and orientation, using a combination of accelerometers, gyroscopes, and magnetometers. BACKGROUND

The background information herein below relates to the present disclosure but is not necessarily prior art.

In normal farming practice, when an operator drives an agricultural vehicle, he brakes the inner wheels at headlands to turn the vehicle in as small an area as possible. This is done to prevent headland wastage and increase productivity of operation. The operator, by his experience/training, can judge the exact point of application and release of brakes and amount of braking force required while turning at headlands. The operator also takes into account soil conditions, vehicle & implement dynamics and modulates the brakes accordingly. In addition to this, the operator gives appropriate steering inputs to keep the vehicle in its intended trajectory.

Most of the conventional autonomous agricultural vehicles also require the operator to manually turn the vehicle after the vehicle reaches an edge of the field. Accordingly, whenever the vehicle reaches the edge of the field (i.e. the headland), the operator is required to change the mode of operation from automatic to manual. This causes reduction in the work efficiency.

In countries where the farm sizes are large, the implement sizes are large as well and this dictates the turning radius of vehicle. In other words, the turning radius of the vehicle is smaller than that of the implement. This allows the vehicle to not contribute towards headland turn wastage. However, in places where landholdings are small, headland wastage significantly affects the farmer. Also, in lower horsepower (i.e. compact and sub-compact) farm machinery, the turning radius is greater than that of the implement. Further, due to small size of the landholdings, the headland turns made are frequent. Hence, a major area of the land is wasted during headland turns.

The farmers try to reduce the headland wastage by following different turning patterns. However, this causes fatigue to the farmers and requires extremely skilled labor. Different headland turn patterns also consume a lot of time and lead to increased soil compaction, thereby reducing efficiency.

Further, places with large farm sizes allow the farmers to turn their vehicles at the headland in K or Y patterns. Hence, essentially, headland turn braking is not required. Although a manual Y-Type or K-type turn solves the problem technically, it also requires great precision by the driver and at the same time induces a lot of fatigue. All this put together, it decreases the efficiency of the driver/farmer. To avoid this, special robots are being developed for effecting headland turning without headland wastage. These robots are designed to work autonomously, but only for a particular application. If the application changes, the robot also needs to be changed or customized. These robots can be two-wheel drive (2WD) or four-wheel drive (4WD) and require Global Navigation Satellite System (GNSS) or perception sensors for precise navigation. The robots comprise of a hydrostatic transmission or electric drive train which enables vehicle control. These are also sometimes remotely operated with a joystick for maneuvering.

Although such robots seem to solve the problem, they are unique only to a particular application and do not follow any existing agricultural standards. Further, they are not conventional farm machineries and hence cannot be afforded by all the farmers (especially farmers of developing nations).

There is, therefore, felt a need for an autonomous headland turning system for an agricultural machine that eliminates the above-mentioned drawbacks.

OBJECTS

Some of the objects of the present disclosure, which at least one embodiment herein satisfies, are as follows:

It is an object of the present disclosure to provide a headland turning system for an agricultural machine.

Another object of the present disclosure is to provide a headland turning system for an agricultural machine that reduces operator fatigue.

Still another object of the present disclosure is to provide a headland turning system for an agricultural machine that reduces headland wastage during turning.

Yet another object of the present disclosure is to provide a headland turning system that facilitates autonomous steering and braking of an agricultural machine.

Still another object of the present disclosure is to provide a headland turning system for an agricultural machine that improves work efficiency. Yet another object of the present disclosure is to provide an autonomous system for an agricultural machine that reduces headland turning time.

Still another object of the present disclosure is to provide a headland turning system for an agricultural machine that can be integrated with the existing Global Navigation Satellite System (GNSS) based auto steer systems.

Other objects and advantages of the present disclosure will be more apparent from the following description, which is not intended to limit the scope of the present disclosure.

SUMMARY

The present disclosure envisages a headland turning system for an agricultural machine. The system comprises a navigation unit, a steering angle sensor, a wheel movement detection means, a steering controller, and a braking controller. The navigation unit is mounted on the agricultural machine and is configured to receive radio signals from a satellite constellation, a correction data from a base station, and data relating to the attitude of the machine from an inertial measurement unit (IMU) to generate guidance commands for steering and braking the agricultural machine. In an embodiment, the navigation unit comprises an antenna, a receiver, and a navigation controller. The antenna is configured to receive radio signals from the satellite constellation. The receiver is configured to cooperate with the antenna to receive the radio signals and determine a current location of the agricultural machine. The receiver is further configured to receive the correction data from the base station to generate a corrected navigation data based on the current position and the correction data. The navigation controller is configured to cooperate with the receiver to receive the corrected navigation data, and is further configured to combine the corrected navigation data with the attitude data to generate a terrain compensated navigation data. The navigation controller is configured to generate the guidance commands for steering and braking the agricultural machine based on the terrain compensated navigation data.

The steering angle sensor is configured to periodically measure steering angle of a steering wheel of the agricultural machine. The wheel movement detection means is configured to detect a movement of the steering wheel by an operator, and is further configured to generate a manual control signal upon detecting the movement. The steering controller is configured to cooperate with the navigation unit and the steering angle sensor to receive the steering guidance commands and the measured steering angle respectively. The steering controller is further configured to generate a steering control signal for actuating a steering actuator based on the received steering guidance commands and measured steering angle. The steering actuator is a hydraulic actuator located within a hydraulic steering control unit (HSU) of the agricultural machine. In an embodiment, the steering controller is configured to cooperate with the wheel movement detection means to turn on manual control of the steering wheel upon receiving the manual control signal.

The braking controller is configured to cooperate with the navigation unit to receive the braking guidance commands, and is further configured to generate a braking control signal for actuating a brake actuator of the agricultural machine based on the received braking guidance commands to reduce headland space wastage during turning.

The attitude data comprises roll, pitch, and yaw of the agricultural machine relative to the terrain, wherein the roll refers to the change in elevation between the left and right sides of the agricultural machine; pitch refers to the change in elevation between the front and rear ends of the agricultural machine; and yaw refers to any sliding or turning motion of the agricultural machine around the agricultural machine’s center of gravity. The IMU consists of a plurality of sensors selected from the group consisting of an accelerometer, a gyroscope, a magnetometer, a pressure sensor and any combinations thereof.

In an embodiment, the system includes a user interface. The user interface is configured with a path planner tool. The path planner tool comprises a memory, a plotting module, and an input module. The memory is configured to store a pre-determined map of a field, wherein the map is defined by plurality of guidelines and a boundary. The plotting module is configured to cooperate with the navigation unit to receive current location of the agricultural machine, and is further configured to cooperate with the memory to map the current location on the field map. The input module is configured to cooperate with the memory to facilitate a user to input feed implement dimensions, number of rounds, number of guidelines, direction of navigation, and position of the boundary to modify the pre-determined field map based on requirement. In an embodiment, the user interface includes a display unit configured to cooperate with the path planner tool to display the modified field map to the operator. In an embodiment, the steering actuator is configured to control steering of the agricultural machine till the time the steering wheel is engaged.

Advantageously, the steering controller includes a fault detecting module configured to detect abnormal conditions associated with navigation of the agricultural machine. The system includes an alerting unit configured to cooperate with the steering controller to alert the operator of the agricultural machine upon detecting the abnormal conditions.

In an embodiment, the system includes at least one feedback sensor associated with the brake actuator and configured to generate feedback commands for the braking controller to provide precision braking control of the agricultural machine based on the braking guidance commands generated by the navigation controller.

Advantageously, the system includes a fuel supply cut-off means configured to facilitate cutting off the fuel supply to the engine of the agricultural machine upon detecting that the agricultural machine has crossed boundary of the field map. In an embodiment, the fuel supply cut-off means is a pull to stop solenoid.

The present disclosure also envisages a headland turning method for an agricultural machine. The method comprises the following steps:

• receiving, by a navigation unit, radio signals from a satellite constellation, a correction data from a base station, and data relating to attitude of the agricultural machine from an Inertial Measurement Unit (IMU);

• generating, by the navigating unit, guidance commands for steering and braking of the agricultural machine based on the received radio signals, the correction data, and the attitude data;

• periodically measuring, by a steering angle sensor, steering angle of a steering wheel of the agricultural machine;

• detecting, by a wheel movement detection means, a movement of the steering wheel of the agricultural machine by an operator;

• generating, by the wheel movement detection means, a manual control signal upon detecting the movement; • receiving, by a steering controller, the steering guidance commands and the measured steering angle;

• generating, by the steering controller, a steering control signal for actuating a steering actuator based on the received steering guidance commands and the measured steering angle;

• receiving, by a braking controller, the braking guidance commands; and

• generating, by the braking controller, a braking control signal for actuating a brake actuator of the agricultural machine based on the received braking guidance commands to reduce headland space wastage during turning. BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWING

A headland turning system for an agricultural machine of the present disclosure will now be described with the help of the accompanying drawing, in which:

Figure 1 illustrates an architecture block diagram of a headland turning system for an agricultural machine; Figure 2 illustrates a block diagram of a user interface of the system of Figure 1;

Figure 3 illustrates a flow diagram depicting a headland turning method for an agricultural machine;

Figure 4 illustrates overlapping headland turn trajectories for a manually operated vehicle without braking vs. a manually operated vehicle with braking; Figure 5 illustrates overlapping headland turn trajectories for a manually operated vehicle without braking vs. a vehicle operated using the system of Figure 1;

Figure 6 illustrates overlapping headland turn trajectories for a manually operated vehicle with braking vs. a vehicle operated using the system of Figure 1; and

Figure 7 illustrates a block diagram of a hydraulic circuit of the system of Figure 1. LIST OF REFERENCE NUMERALS

100 - System

102 - Navigation unit

104 - Steering angle sensor

106 - Wheel movement detection means

108 - Steering controller

110 - Braking controller

112 - Brake actuator

114 - Antenna

116 - Receiver

118 - Navigation controller

120 - User interface

122 - Hydraulic Steering Unit (HSU)

124 - Alerting unit

126 - Fuel supply cut-off means

128 - Electric Quick Lift (EQL) switch 130 - Emergency Switch

132 - Brake latch switch

134 - Range switch

136 - Electric Quick Lift (EQL) motor 202 - Memory

204 - Plotting module 206 - Input module 208 - Path planner tool 210 - Display unit

700 - Hydraulic circuit 702, 704 - Hydraulic pumps 706 - Filter

708 - Steering cylinder 710 - Steering wheel

712 - Hitch control mechanism 714 - Battery

DETAILED DESCRIPTION

Embodiments, of the present disclosure, will now be described with reference to the accompanying drawing.

Embodiments are provided so as to thoroughly and fully convey the scope of the present disclosure to the person skilled in the art. Numerous details, are set forth, relating to specific components, and methods, to provide a complete understanding of embodiments of the present disclosure. It will be apparent to the person skilled in the art that the details provided in the embodiments should not be construed to limit the scope of the present disclosure. In some embodiments, well-known processes, well-known apparatus structures, and well-known techniques are not described in detail. The terminology used, in the present disclosure, is only for the purpose of explaining a particular embodiment and such terminology shall not be considered to limit the scope of the present disclosure. As used in the present disclosure, the forms "a,” "an," and "the" may be intended to include the plural forms as well, unless the context clearly suggests otherwise. The terms "comprises," "comprising,"“including,” and“having,” are open ended transitional phrases and therefore specify the presence of stated features, integers, steps, operations, elements, modules, units and/or components, but do not forbid the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. The particular order of steps disclosed in the method and process of the present disclosure is not to be construed as necessarily requiring their performance as described or illustrated. It is also to be understood that additional or alternative steps may be employed.

When an element is referred to as being "mounted on,"“engaged to,” or "connected to," another element, it may be directly on, engaged, or connected to the other element.

The terms first, second, third, etc., should not be construed to limit the scope of the present disclosure as the aforementioned terms may be only used to distinguish one element from another element. Terms such as first, second, third etc., when used herein do not imply a specific sequence or order unless clearly suggested by the present disclosure.

Terms such as“inner,”“outer,” "beneath," "below," "lower," "above," "upper," and the like, may be used in the present disclosure to describe relationships between different elements as depicted from the figures.

A headland turning system for an agricultural machine (hereinafter referred as“system 100”), of the present disclosure, is now being described with reference to Figure 1 through Figure 7.

Referring to Figure 1, the system 100 comprises a navigation unit 102, a steering angle sensor 104, a wheel movement detection means 106, a steering controller 108, and a braking controller 110. The navigation unit 102 is mounted on the agricultural machine and is configured to receive radio signals from a satellite constellation, a correction data from a base station, and data relating to the attitude of the machine from an inertial measurement unit (IMU), to generate guidance commands for steering and braking the agricultural machine. The steering angle sensor 104 is configured to periodically measure steering angle of a steering wheel 710 of the agricultural machine. The wheel movement detection means 106 is configured to detect a movement of the steering wheel 710 by an operator, and is further configured to generate a manual control signal upon detecting the movement. The steering controller 108 is configured to cooperate with the navigation unit 102 and the steering angle sensor 104 to receive the steering guidance commands and the measured steering angle respectively. The steering controller 108 is further configured to generate a steering control signal for actuating a steering actuator based on the received steering guidance commands and the measured steering angle.

In an embodiment, the steering angle sensor 104 also measures the turning rate of the agricultural machine and sends the measured turning rate to the steering controller 108. The steering controller 108 generates a steering control signal for actuating the steering actuator based on the received steering guidance commands, the measured steering angle, and the measured turning rate.

In an embodiment, the steering controller 108 is configured to generate the steering control signal till the time the steering wheel 710 is engaged. When the steering wheel 710 is disengaged or moved, the wheel movement detection means 106 generates the manual control signal which causes the steering controller 108 to stop generating the steering control signal and turn on manual control (manual operation mode) of the agricultural machine. In an embodiment, the wheel movement detection means 106 is a pressure transducer. The braking controller 110 is configured to cooperate with the navigation unit 102 to receive the braking guidance commands, and is further configured to generate a braking control signal for actuating a brake actuator 112 of the agricultural machine based on the received braking guidance commands to reduce headland space wastage during turning. The agricultural machine can either have two brake actuators 112 (i.e. left brake actuator and right brake actuator) or a single brake actuator 112.

In an embodiment, the navigation unit 102 comprises an antenna 114, a receiver 116, and a navigation controller 118. The antenna 114 is configured to receive radio signals from the satellite constellation. The receiver 116 configured to cooperate with the antenna 114 to receive the radio signals and determine a current location of the agricultural machine. In an embodiment, the antenna 114 is a Global Navigation Satellite System (GNSS) antenna and the receiver 116 is a GNSS receiver. The receiver 116 is further configured to receive the correction data from the base station to generate a corrected navigation data based on the current position and the correction data. The navigation controller 118 is configured to cooperate with the receiver 116 to receive the corrected navigation data, and is further configured to combine the corrected navigation data with the attitude data to generate a terrain compensated navigation data. The navigation controller 118 is configured to generate the guidance commands for steering and braking the agricultural machine based on the terrain compensated navigation data. The attitude data comprises roll, pitch, and yaw of the agricultural machine relative to the terrain. The IMU includes a plurality of sensors to measure roll, pitch, and yaw of the agricultural machine. The sensors are selected from the group consisting of an accelerometer, a gyroscope, a magnetometer, a pressure sensor, and any combinations thereof. In an embodiment, the steering controller 108 receives measured parameters such as steering angle, turning rate, and wheel movement detection from corresponding sensors and communicates the measured parameters with the navigation unit 102.

Referring to an embodiment of Figure 2, the system 100 includes a user interface 120 configured with a path planner tool 208. The path planner tool 208 comprises a memory 202 and a plotting module 204. The memory 202 is configured to store a pre-determined map of a field, wherein the map is defined by plurality of guidelines and a boundary. The plotting module 204 is configured to cooperate with the navigation unit 102 to receive current location of the agricultural machine, and is further configured to cooperate with the memory 202 to map the current location on the field map. The input module 206 is configured to cooperate with the memory 202 to facilitate the operator to input feed implement dimensions, number of rounds, number of guidelines, direction of navigation, and position of the boundary to modify the pre-determined field map based on requirement. The user interface 120 includes a display unit 210 configured to cooperate with the path planner tool 208 to display the modified field map to the operator. In an embodiment, the steering controller 108 includes a fault detecting module configured to detect abnormal conditions associated with navigation of the agricultural machine. For example, the fault detecting module may detect conditions such as vehicle approaching boundary of the field and lost GPS signal. The system 100 further includes an alerting unit 124 configured to cooperate with the steering controller 108 to alert the operator of the agricultural machine upon detecting the abnormal conditions. The alerting unit 124 can be selected from the group consisting of buzzers, alarms, indicators, and the like.

In an embodiment, the system 100 includes at least one feedback sensor associated with the brake actuator 112. The feedback sensor is configured to generate feedback commands for the braking controller 110 to provide precision braking control of the agricultural machine based on the braking guidance commands generated by the navigation controller 118.

Advantageously, the system 100 includes a fuel supply cut-off means 126 connected to the steering controller 108. The fuel supply cut-off means 126 is configured to cut off the fuel supply to the engine of the agricultural machine upon detecting that the agricultural machine has crossed boundary of the field map. In an embodiment, the fuel supply cut-off means 126 is a pull to stop solenoid.

Additionally, the system 100 includes a brake latch switch 132 and a range switch 134. The brake latch is connected to the steering controller 108. Activation of the brake latch switch 132 results in deactivation of the brake assisted turning feature of the system 100. In an embodiment, upon the operation of the brake latch switch 132, the steering controller 108 bypasses braking guidance commands received from the navigation unit 102. The brake latch switch 132 thus helps in preventing application of both the brakes during turning of the agricultural machine. In an embodiment, the range switch 134 allows an operator to set the high speed and low speed settings for the headland turning system 100 of the present disclosure. The steering controller 108 cooperates with the range switch 134 to receive the high and low speed settings. The steering controller 108 generates the steering control signals during turning based on the high and low speed settings.

Figure 7 shows a block diagram of a hydraulic circuit 700 of the system 100. The hydraulic circuit 700 includes the hydraulic steering circuit and a hydraulic lift circuit. There are two hydraulic pumps (702, 704) in the agricultural machine. The first pump 702 is for hydraulic steering circuit and the second pump is for hydraulic lift circuit. The hydraulic pumps (702, 704) receive oil through a filter 706. The steering cylinder 708 moves left or right as per the oil flow direction in to it. When the steering wheel 710 is turned left, the spool inside an integrated Hydraulic Steering Unit (HSU) 122 moves to one side, which causes the oil to flow from P port to L port and from R port to T port of the cylinder 708 and vice versa when the steering wheel 710 is turned right. Similarly, when the steering is controlled by the navigation unit 102 operated steering controller 108, same phenomenon (movement of spool inside the HSU 122) takes place. In other words, when the integrated HSU 122 receives commands from the steering controller 108, it moves the spool inside it and performs the steering action.

Advantageously, the system 100 further includes an electric quick lift (EQL) switch 128 and an EQL motor 136. The EQL switch 128 facilitates the operator to lift or lower an implement attached to the agricultural machine. The EQL switch 128 is connected to the steering controller 108. In an embodiment, the operation of EQL switch 128 results in generation of an implement raise or lower signal. The steering controller 108 receives the raise or lower signal from the EQL switch 128 and generates corresponding raise or lower commands for operating the EQL motor 136. The EQL motor 136 adjusts the position of the spool valve in a hydraulic lift unit to raise or lower the implement. When the EQL motor 136 is activated in one direction, it moves the spool inside the hydraulic lift unit, thereby allowing the oil to flow in to the lift cylinder and the implement to be lifted. Similarly, if the motor 136 is activated in another direction, the spool is moved in other direction which allows the implement to be lowered. The implement is connected to the agricultural machine through a hitch control mechanism 712. In an embodiment, the steering controller 108 is powered from a battery 714.

Advantageously, the system 100 comprises an emergency switch 130 for switching the automatic steering and braking (autonomous headland turning system) 100 off in dangerous circumstances. The emergency switch 130 may be mounted directly on the vehicle steering wheel 710. Referring to Figure 3, the present disclosure also envisages a headland turning method 300 for an agricultural machine. The method 300 comprises method the following steps:

Step 302 - Receiving, by a navigation unit 102, radio signals from a satellite constellation, a correction data from a base station, and data relating to attitude of the agricultural machine from an Inertial Measurement Unit (IMU).

Step 304 - Generating, by the navigating unit 102, guidance commands for steering and braking of the agricultural machine based on the received radio signals, the correction data, and the attitude data.

Step 306 - Periodically measuring, by a steering angle sensor 104, steering angle of a steering wheel 710 of the agricultural machine.

Step 308 - Detecting, by a wheel movement detection means 106, a movement of the steering wheel 710 of the agricultural machine by an operator.

Step 310 - Generating, by the wheel movement detection means 106, a manual control signal upon detecting the movement.

Step 312 - Receiving, by a steering controller 108, the steering guidance commands and the measured steering angle.

Step 314 - Generating, by the steering controller 108, a steering control signal for actuating a steering actuator based on the received steering guidance commands and the measured steering angle.

Step 316 - Receiving, by a braking controller 110, the braking guidance commands.

Step 318 - Generating, by the braking controller 110, a braking control signal for actuating a brake actuator 112 of the agricultural machine based on the received braking guidance commands to reduce headland space wastage during turning.

In an embodiment, the method 300 includes the step of turning on, by the steering controller 108, the manual control of the steering wheel 710 upon receiving the manual control signal.

In an embodiment, the method 300 includes the step of setting, using the braking controller 110, braking force for different steering wheel angle values.

In an embodiment, the method 300 includes detecting, by a feedback sensor, an actual braking force, generated by the brake actuator 112, generating, by the feedback sensor, feedback commands corresponding to the detected braking force, receiving, by the braking controller 110, the generated feedback commands from the feedback sensor, and generating, by the braking controller 110, a control signal corresponding to a difference between braking guidance commands and the feedback commands for actuating the brake actuator 112.

The braking controller 110 is designed to vary the braking force with the steering angle during the steering maneuver of the agricultural machine. Similarly, the braking controller 110 is designed to reverse the braking force during steering return maneuver i.e. while bringing the steered wheels back to straight ahead condition.

The turning radius of an agricultural machine was measured and compared for different scenarios. The results of comparison are summarized in Figures 4, 5, and 6. From the figures, it can be seen that the agricultural machine operated using the headland turning system 100 of the present disclosure requires lesser turning radius than a manually operated vehicle without braking and almost same radius as that required by a manually operated vehicle with braking. The turning radius for a manually operated vehicle with braking depends on the skill and experience of the operator. More specifically, the headland turning system 100 of the present disclosure results in reduction of turning radius by about 15% to 35% as compared to a manually operated vehicle without braking. The percentage reduction in turning radius depends on soil, implement, and dimensions of the agricultural machine. Further, turning the agricultural machine each time it reaches the end of the field, such that it consumes a minimum turning radius, leads to operator fatigue. Thus, the autonomous headland turning system 100 provides minimum turning radius and helps eliminate operator fatigue.

The foregoing description of the embodiments has been provided for purposes of illustration and not intended to limit the scope of the present disclosure. Individual components of a particular embodiment are generally not limited to that particular embodiment, but, are interchangeable. Such variations are not to be regarded as a departure from the present disclosure, and all such modifications are considered to be within the scope of the present disclosure. TECHNICAL ADVANCEMENTS

The present disclosure described herein above has several technical advantages including, but not limited to, the realization of a headland turning system for an agricultural machine that:

• reduces operator fatigue;

• reduces headland wastage during turning;

• reduces headland turning time;

• can be integrated with the existing Global Navigation Satellite System (GNSS) based auto steer systems;

• facilitates autonomous steering and braking of an agricultural machine; and

• improves work efficiency.

The embodiments herein and the various features and advantageous details thereof are explained with reference to the non-limiting embodiments 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.

The foregoing description of the specific embodiments 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 preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.

The use of the expression“at least” or“at least one” suggests the use of one or more elements or ingredients or quantities, as the use may be in the embodiment of the disclosure to achieve one or more of the desired objects or results.

The numerical values mentioned for the various physical parameters, dimensions or quantities are only approximations and it is envisaged that the values higher/lower than the numerical values assigned to the parameters, dimensions or quantities fall within the scope of the disclosure, unless there is a statement in the specification specific to the contrary. While considerable emphasis has been placed herein on the components and component parts of the preferred embodiments, it will be appreciated that many embodiments can be made and that many changes can be made in the preferred embodiments without departing from the principles of the disclosure. These and other changes in the preferred embodiment as well as other embodiments of the disclosure will be apparent to those skilled in the art from the disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the disclosure and not as a limitation.

Claims

CLAIMS:

1. A headland turning system (100) for an agricultural machine, said system (100) comprising:

i. a navigation unit (102) configured to receive radio signals from a satellite constellation, a correction data from a base station, and data relating to the attitude of the machine from an inertial measurement unit (IMU), to generate guidance commands for steering and braking the agricultural machine;

ii. a steering angle sensor (104) configured to periodically measure steering angle of a steering wheel (710) of the agricultural machine;

iii. a wheel movement detection means (106) configured to detect a movement of said steering wheel (710) by an operator, and further configured to generate a manual control signal upon detecting said movement;

iv. a steering controller (108) configured to cooperate with said navigation unit (102) and said steering angle sensor (104) to receive said steering guidance commands and said measured steering angle respectively, said steering controller (108) further configured to generate a steering control signal for actuating a steering actuator based on said received steering guidance commands and measured steering angle; and

v. a braking controller (110) configured to cooperate with said navigation unit (102) to receive said braking guidance commands, and further configured to generate a braking control signal for actuating a brake actuator (112) of the agricultural machine based on said received braking guidance commands to reduce headland space wastage during turning.

2. The system as claimed in claim 1, wherein said navigation unit (102) is mounted on the agricultural machine.

3. The system as claimed in claim 2, wherein said navigation unit (102) comprises: i. an antenna (114) configured to receive radio signals from said satellite constellation;

ii. a receiver (116) configured to cooperate with said antenna (114) to receive said radio signals and determine a current location of the agricultural machine, said receiver (116) further configured to receive said correction data from said base station to generate a corrected navigation data based on said current position and said correction data; and

iii. a navigation controller (118) configured to cooperate with said receiver (116) to receive said corrected navigation data, and further configured to combine said corrected navigation data with said attitude data to generate a terrain compensated navigation data, said navigation controller (118) configured to generate said guidance commands for steering and braking the agricultural machine based on said terrain compensated navigation data.

4. The system as claimed in claim 1, wherein said attitude data comprises roll, pitch, and yaw of the agricultural machine relative to said terrain.

5. The system as claimed in claim 1, wherein said IMU consists of a plurality of sensors selected from the group consisting of an accelerometer, a gyroscope, a magnetometer, a pressure sensor and any combinations thereof.

6. The system as claimed in claim 1, wherein said steering controller (108) is configured to cooperate with said wheel movement detection means (106) to turn on manual control of said steering wheel upon receiving said manual control signal.

7. The system as claimed in claim 1, wherein said wheel movement detection means (106) is a pressure transducer.

8. The system as claimed in claim 3, wherein said system (100) includes a user interface (120) configured with a path planner tool (208), said path planner tool (208) comprising:

i. a memory (202) configured to store a pre-determined map of a field, wherein said map is defined by plurality of guidelines and a boundary;

ii. a plotting module (204) configured to cooperate with said navigation unit (102) to receive current location of the agricultural machine, and further configured to cooperate with said memory (202) to map said current location on said field map; and

iii. an input module (206) configured to cooperate with said memory (202) to facilitate the operator to input feed implement dimensions, number of rounds, number of guidelines, direction of navigation, and position of said boundary to modify said pre-determined field map based on requirement.

9. The system as claimed in claim 8, wherein said user interface (120) includes a display unit (210) configured to cooperate with said path planner tool (208) to display said modified field map to the operator.

10. The system as claimed in claim 1, wherein said steering controller (108) is configured to generate the steering control signal till the time the steering wheel (710) is engaged.

11. The system as claimed in claim 1, wherein said steering controller (108) includes a fault detecting module configured to detect abnormal conditions associated with navigation of the agricultural machine.

12. The system as claimed in claim 11, wherein said system (100) includes an alerting unit (124) configured to cooperate with said steering controller (108) to alert the operator of the agricultural machine upon detecting said abnormal conditions.

13. The system as claimed in claim 3, wherein said system (100) includes at least one feedback sensor associated with said brake actuator (112), said feedback sensor configured to generate feedback commands for said braking controller (110) to provide precision braking control of the agricultural machine based on said braking guidance commands generated by said navigation controller (118).

14. The system as claimed in claim 8, wherein said system (100) includes a fuel supply cut-off means (126) configured to cut off the fuel supply to the engine of the agricultural machine upon detecting that the agricultural machine has crossed boundary of said field map.

15. The system as claimed in claim 14, wherein said fuel supply cut-off means (126) is a pull to stop solenoid.

16. A headland turning method (300) for an agricultural machine, said method (300) comprising the following steps:

i. receiving, by a navigation unit (102), radio signals from a satellite constellation, a correction data from a base station, and data relating to attitude of the agricultural machine from an Inertial Measurement Unit (IMU);

ii. generating, by said navigating unit (102), guidance commands for steering and braking of the agricultural machine based on said received radio signals, said correction data, and said attitude data; iii. periodically measuring, by a steering angle sensor (104), steering angle of a steering wheel of the agricultural machine;

iv. detecting, by a wheel movement detection means (106), a movement of said steering wheel of the agricultural machine by an operator;

v. generating, by said wheel movement detection means (106), a manual control signal upon detecting said movement;

vi. receiving, by a steering controller (108), said steering guidance commands and said measured steering angle;

vii. generating, by said steering controller (108), a steering control signal for actuating a steering actuator based on said received steering guidance commands and said measured steering angle;

viii. receiving, by a braking controller (110), said braking guidance commands; and ix. generating, by said braking controller (110), a braking control signal for actuating a brake actuator (112) of the agricultural machine based on said received braking guidance commands to reduce headland space wastage during turning.

17. The method as claimed in claim 16, wherein said method (300) includes the step of turning on, by said steering controller (108), manual control of said steering wheel upon receiving said manual control signal.

18. The method as claimed in claim 16, wherein said method (300) includes the step of setting, using said braking controller (110), braking force for different steering wheel angle values.

19. The method as claimed in claim 18, wherein said method (300) includes:

i. detecting, by a feedback sensor, an actual braking force, generated by said brake actuator (112);

ii. generating, by said feedback sensor, feedback commands corresponding to said detected braking force;

iii. receiving, by said braking controller (110), said generated feedback commands from said feedback sensor; and

iv. generating, by said braking controller (110), a control signal corresponding to a difference between braking guidance commands and said feedback commands for actuating said brake actuator (112).

20. The method as claimed in claim 16, wherein said wheel movement detection means

(106) is a pressure transducer.