The present invention relates to an autonomous system for low payload gripper changing mechanism and its method thereof. Particularly, the present invention relates to a system and method to change the end effector of a gripper of an agricultural robot that is being deployed into remote fields with multiple crops. Further, the harvester works without any human intervention and therefore, it needs autonomous gripper changing mechanisms to effectively harvest different type of crops.
BACKGROUND OF THE INVENTION
[002] Harvesters presently available in the market, works mostly on one crop and if they work on multiple crops then they require heavy machinery to change the grippers. The size of the machine used to change the grippers is not practically viable for a remote vehicle or machine working in small and limited spaces.

[003] The current mechanisms available in the public domain are complex and are time-consuming when it comes to application. Further, some setups require human intervention to facilitate the change of grippers.

[004] US 20190029178A1 discloses a crop picking end effector for robotic harvesting of crops. A cutting mechanism is arranged on the body and is operable to cut a stem or stalk of the crop and a gripper is operable to attach itself to the crop. A decoupling mechanism including a tether connected to the gripper and tethering the gripper with respect to the body and a releasable securing mechanism which secures the gripper with respect to the cutting mechanism and is configured to allow the gripper to decouple, thereby to release the gripper with respect to the cutting mechanism. The cited prior art document usually has a single type of gripper or even if different grippers are used the gripper has to be changed manually.

[005] EP0155362A1 discloses a gripper tool changer for a multi-axis manipulator is provided which is capable of automatically attaching in locked position a selected pair of a plurality of gripper pads or tools to the fingers of a gripper. Each pair of gripper pads or tools are mounted in a holder mechanism which is attached to a surface within the work envelope of the manipulator. The pairs of gripper pads or tools are picked up from the holder and attached and locked to the gripper fingers by controlled movement of the manipulator. A pair of gripper pads or tools are returned to the holder by controlled maneuvering of the gripper into the holder such that unlocking means associated therewith provide unlocking of the gripper pads or tools from the gripper fingers so that the gripper pads or tools can be detached from the gripper fingers. The cited prior art document has a changing mechanism usually present in warehouses in a constant environment rather than a dynamic harvester such as this harvester. It involves complex time-consuming mechanisms which make the process inefficient.

[006] In the existing prior arts disclosed herein there are gripper changing mechanism which are complex in nature. Further, the existing prior arts are not suitable to work in remote or small and limited spaces and some setups require human intervention to change the gripper.

[007] Therefore, keeping in view of the problems associated with the state of the art, there is a need of gripper changing mechanism which is autonomous, economical, less time-consuming, and simpler than all the current existing inventions. And works without any human intervention and thus making it feasible and convenient in remote areas.

OBJECTIVES OF THE INVENTION
[008] The primary objective of the present invention is to provide an autonomous system for changing the end effector of a gripper of an agricultural robot and its method of working.

[009] Another objective of the invention is to provide a mechanism which is free from human intervention.

[0010] Yet another objective of the invention is to provide a mechanism which is fast, efficient and light in weight comprising of easily replaceable parts.

[0011] Another objective of the present invention is to improve the harvesting process with the help of robotic industrial arms for picking plant-based crops.

[0012] Yet another objective of the present invention is to help the robotic arm to change the end effector according to its needs through the changing mechanism.

[0013] Another objective of the present invention is to remove human intervention required in the changing mechanism and the changing process.

[0014] Yet another objective is to provide simple and easy replaceable parts.

[0015] Other objective and advantages of the present invention will become apparent from the following description taken in connection with the accompanying drawings, wherein, by way of illustration and example, the aspects of the present invention are disclosed.

SUMMARY OF THE INVENTION

[0016] The present invention relates to an autonomous system for low payload gripper changing mechanism and its method thereof to change the end effector of a gripper of an agricultural robot that is being deployed into remote fields with multiple crops. The present invention exemplifies the improved efficiency of robotic arms employed in agriculture harvesting machines and other automated processes that utilizes a robotic arm. Heavy machineries are assisted by humans to change grippers for harvesting different crops whereas the present invention consists of simple and replaceable parts like a gripper cabinet, changing link and robotic arm as last link. An array of grippers having distinct features, shapes and sizes can be replaced on the cabinet system. The gripper is mounted on the changing link for easy engage and disengage operation. The unique design of changing link restricts motion in the cabinet in only one direction and does not allow any rotation, the L shaped slot helps to lock the gripper to prevent slipping. When the link needs to be disengaged with the robotic arm, the arm places the gripper onto the gripper cabinet and then rotates the last link to align with the slot present and then pulls out of the changing link. The connector link consists of electrical terminals for transmission of current during gripper operation and the circuit is completed when the slot is locked with the last link of robotic arm. The invention is very flexible to a variety of robotic arms, grippers both soft and under actuated with ample amount of space for additional mountings like sensors, camera etc thus forming a low cost solution to autonomous systems and agriculture machinery.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Figure 1 illustrates the complete assembly of the system of the present invention;

[0018] Figure 2 illustrates the exploded view of Changing link and Robotic arm last link assembly;

[0019] Figure 3 illustrates the locked state of changing link and robotic arm;

[0020] Figure 4 illustrates different site views of changing link and

[0021] Figure 5 illustrates perspective view of gripper cabinet assembly; and

[0022] Figure 6 represents the working flowchart for changing gripper in agricultural harvesting machines via the system of the present invention.

[0023] Reference numerals for the components of the system are enlisted herein:

S. No. Components Reference Numerals
1. Robotic arm 101
2. Gripper 102
3. Gripper cabinet 103
4. Changing links 104
5. Connector 105
6. Terminals 106

DETAILED DESCRIPTION OF THE INVENTION

[0024] The following description describes various features and functions of the disclosed mechanism with reference to the accompanying figures. In the figures, similar symbols identify similar components, unless context dictates otherwise. The illustrative aspects described herein are not meant to be limiting. It may be readily understood that certain aspects of the disclosed system can be arranged and combined in a wide variety of different configurations, all of which have not been contemplated herein.

[0025] Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the embodiments described herein can be made without departing from the scope of invention. In addition, descriptions of well-known functions and constructions are omitted for clarity and conciseness.

[0026] Features that are described and/or illustrated with respect to one embodiment may be used in the same way or in a similar way in one or more other embodiments and/or in combination with or instead of the features of the other embodiments.

[0027] The terms and words used in the following description are not limited to the bibliographical meanings, but, are merely used to enable a clear and consistent understanding of the invention. Accordingly, it should be apparent to those skilled in the art that the following description of exemplary embodiments of the present invention are provided for illustrative purpose only and not for the purpose of limiting the invention.

[0028] It is to be understood that the singular forms “a”, “an” and “the” include plural referents unless the context clearly dictates otherwise.

[0029] It should be emphasized that the term “comprises/comprising” when used in this specification is taken to specify the presence of stated features, integers, steps or components but does not preclude the presence or addition of one or more other features, integers, steps, components or groups thereof.

[0030] The present invention relates to an autonomous mechanism to change the end effector of a gripper (102) of an agricultural robot that is being deployed into remote fields with multiple crops. The invention mainly includes the following components i.e., a gripper cabinet (103), a changing link, and a robotic arm last link (101). The grippers (103) are embedded on the gripper cabinet (103) and the arm moves to the cabinet position to align itself with the changing link (104) present on the gripper cabinet (103). This process of alignment is a pre-planned trajectory that is fixed in the controller of the arm which is executed by the arm when it is called for. After aligning with the changing link (104), the arms move into the link and after reaching a specific distance the last link of the arm rotates and locks into the L-slot present on the changing link (104). Once the changing link (104) and the arm are locked the gripper (102) is removed from the cabinet and is ready to be used. Along with the mechanical connection the electrical circuit is being completed with the help of terminals (106) that are present in the changing link (104) and the robotic arms (101) end of the robot.

[0031] Figure 1 illustrates the complete assembly of the system (100) of the present invention including the following components i.e., the robotic arm (101), the changing link (104), and the gripper cabinet (103). The components of the present invention are described in detail herein:

(a) Gripper cabinet (103): In an embodiment of the present invention the grippers (102) are embedded in gripper cabinet (103). The gripper cabinet (103) comprises a planner sheet metal design having deep grooves cut into specific shapes for accommodating the changing links (104) that are a part of grippers (102). The depth of the groove is deeply carved out to prevent the gripper (102) from falling off when mounted on the cabinet. The positioning of the gripper (102) in the cabinet allows its motion in vertical direction only.

(b) Changing link (104): In an embodiment of the present invention the gripper (102) is mounted on the changing link (104) and one end of the link is used to engage and disengage with the gripper (102). The link has been designed into a structure that restricts its motion in the cabinet in only one direction and does not allow any rotation. Figure 2 illustrates the exploded view of Changing link (104) and Robotic arm (101) last link assembly. The end of the changing link (104) that interacts with the robotic arm (101) comprises an L-shaped slot carved into it that provides locking of the gripper (102) to prevent slipping as illustrated in Figure 3. On engaging the link with the arm, the movement takes place in one direction and not in the other direction as this helps to prevent slipping of the link from the robotic arm (101). Further, for disengaging the link with the robotic arm (101), the arm places the gripper (102) onto the gripper cabinet (103) and then rotates the last link to align with the slot present and then pulls out of the changing link (104). The changing link (104) also has two terminals (106) to get in contact with terminals (106) that are present on the arm end which helps in completing the electrical circuit. The changing link (104) gets replaced every time the gripper (102) is changed and in order to maintain the electrical connectivity of the gripper (102) with the arm, the robotic arm (101) has these two terminals (106) that align with the terminals (106) present on the changing link (104) to complete the circuit every time the gripper (102) is changed. In an exemplary embodiment, Figure 4 illustrates different site views of changing link (104). The changing links (104) are attached to different grippers (102) which are then stored onto the gripper cabinet (103) in a fixed orientation. The arm can engage and disengage with the changing link (104) with help of preplanned pathways.

(c) Connecter (105): In an embodiment of the present invention the connector (105) is designed to fit into the changing link (104) and locks in the slot that is carved on the changing link (104). Further, the connector (105) provides connection between changing link (104) and robotic arm (101). The connector (105) comprises two terminals (106) that join the terminals (106) in the changing link (104) and completes the circuit. Further, it is fitted on to the robotic arm (101) and helps to change between different grippers (102) present on the gripper cabinet (103). Figure 2 illustrates the connection of the connector (105) between the robotic arm (101) and changing link (104).

(d) Robotic Arm (101): The robotic arm (101) helps in planning the trajectory to the changing link (104) that is mounted onto the gripper cabinet (103). The trajectories are pre-planned ones which are stored in the controllers and this arm is an off-the-shelf robotic arm (101). The robotic arm (101) is controlled by an arm controller that comes as a bundle with the arm controller performing actions such as pick and place, grab, release, and gripper (102) changing. Figure 5 illustrates a Gripper cabinet (103) assembly; cabinet holds the grippers (102) in a particular orientation which helps the robotic arm (101) to engage and disengage with the robotic arm (101).

(e) Arm controller: The arm controller is an off-the-shelf electronic component that comes along the robotic arm (101). The controller is programmable for managing the arm by feeding the coordinate or the joints angle to the robotic arm (101).

(f) Software Module: In an embodiment of the present invention a Motion planning framework Moveit is being utilized. The software module is a robotic arm (101) manipulation module based on (Robot Operating System) ROS for manipulation, motion planning, kinematics, Collision Checking, etc. The location of the grippers (102), the joint angles and poses are pre-fed into the memory of the system (100). When the robotic arm (101) is given command to change a particular gripper (102), the robotic arm (101) moves up to the gripper holder in a specified path with the help of forward kinematics and engage with the gripper (102) and pulls it out of the gripper cabinet (103). Further, when the command to disengage is given the robotic arm (101) follows the same process as the engagement, the only difference being the direction of rotation of the last link at the time of locking.

[0032] The method for working of the system (100) of the present invention includes the following steps:
? incorporating the required input from the user for the gripper (102) to the robotic arm controller;
? manipulating the robotic arm (101) through the robotic arm controller to connect with gripper (102);
? engaging robotic arm (101) with the connector (105) stored in the cabinet with the desired gripper (102);
? moving the robotic arm (101) in rotational direction for connecting and locking with the connector (105); and
? pulling outwards the robotic arm (101) connected with the gripper (102) from gripper cabinet (103).

[0033] The advantage of the present invention includes:
? improving the harvesting process with the help of robotic industrial arms for picking plant-based crops;
? changing mechanism helps the robotic arm to change the end effector according to its needs;
? No human intervention is required in the changing mechanism and the changing process;
? For remote vehicles (such as a harvester in a field) the gripper changing operation can be conducted without human assistance; and
? The mechanism comprises of simple and easily replaceable parts.

[0034] While this invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the scope of the appended claims.

WE CLAIM:

1) An autonomous system (100) for changing gripper (102) in agricultural harvesting machines comprises:
? a gripper cabinet (103) configured to embed the gripper (102);
? a changing link (104) mounting the gripper (102);
? a connector (105) with electrical terminals (106);
? a robotic arm (101) configured to follow the planned trajectory to the changing link (104); and
? a software module configured to manipulate the movement of robotic arm (101);
wherein
? the changing link (104) is configured to move in one direction;
? the changing link (104) is configured to engage and disengage with the gripper (102);
? the changing link (104) comprises a L shaped slot; and
? the changing link (104) and the robotic arm (101) locks into the L-slot to prevent slippage.

2) The autonomous system (100) as claimed in claim 1, wherein the gripper cabinet (103) comprises deep groves to accommodate grippers (102) and changing link (104) to allow vertical movement.

3) The autonomous system (100) as claimed in claim 1, wherein the changing link (104) includes a L shaped slot and electrical terminals (106).

4) The autonomous system (100) as claimed in claim 1, wherein the changing link (104) moves in one direction and have no rotational motion.

5) The autonomous system (100) as claimed in claim 1, wherein the connector (105) is configured to fit into the slots of changing link (104) for completing the circuit.

6) The autonomous system (100) as claimed in claim 1, wherein the robotic arm (101) comprises pre- planned trajectories stored in the controllers.
7) A method for changing gripper (102) in agricultural harvesting machines via the autonomous system (100) as claimed in claim 1 comprises of the following steps:
? incorporating the required input from the user for the gripper (102) to the robotic arm controller;
? manipulating the robotic arm (101) through the robotic arm controller to connect with gripper (102);
? engaging robotic arm (101) with the connector (105) stored in the cabinet with the desired gripper (102);
? moving the robotic arm (101) in rotational direction for connecting and locking with the connector (105); and
? pulling outwards the robotic arm (101) connected with the gripper (102) from gripper cabinet (103).