One technical field of the present disclosure is mechanical devices for picking up objects. Another technical field is robotic systems using techniques based on two-dimensional Cartesian designs to grasp a moving object.
Robotic systems are used in many industries to perform simple repetitive tasks such as grasping, picking up, and moving objects. The installation of such systems offers many benefits, which include lower financial cost to perform basic tasks, as well as mitigation of physical risk to humans from performing such tasks in dangerous environments, such as manufacturing, warehousing, or waste processing facilities.
In a basic use case, a robotic system may be used to pick up homogenous static objects, such as pallets stacked in a pile. In a more complex use case, a robotic system may be used to pick up moving objects that are heterogeneous in size, shape, and placement, such as mixed refuse moving on a conveyor belt in a recycling or waste handling facility. Robots of the current art are often large, complex, and expensive to build. Therefore, a need exists for a robotic system that is able to pick up heterogenous moving objects, but that is smaller and less mechanically complex than the robotic systems commonly used today. A smaller, simpler system is much more viable than robots of the current art, both because of its lower cost and because it would be significantly easier to install.
In one construction, the invention provides a catching mechanism including an end effector and a return mechanism coupled to the end effector. The catching mechanism has a defined field of motion that permits the end effector to move in at least one dimension. The return mechanism is configured to return the catching mechanism to a predetermined starting position when the catching mechanism is not being moved by a force away from the predetermined starting position.
In another construction, the invention provides a robotic system for picking up objects including a catching mechanism and a robotic frame. The catching mechanism includes a return mechanism and an end effector movable from a starting position when the end effector makes contact with a target object. The robotic frame is configured to move the at least one catching mechanism to a predetermined position in order to make initial contact with the target object. The robotic frame moves the catching mechanism to a predetermined position such that the catching mechanism can sustain contact with the target object for a period of time to grasp the target object. The return mechanism is configured to return the catching mechanism back to the starting position if the end effector moves during the sustained contact with the target object.
In yet another construction, the invention provides a robotic grasping system for picking up objects including a first rail, a first carriage movably mounted to the first rail, a second carriage mounted to the first carriage, a second rail movably mounted to the second carriage, and a catching mechanism coupled to an end portion of the second rail. The first carriage is movable in a first dimension. The second rail is movable in a second dimension that is different from the first dimension. The catching mechanism is configured to engage with a target object moving in a third dimension which is different from the first dimension and the second dimension.
Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting.
The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. As used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well as the singular forms, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and/or groups thereof.
Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one having ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and the present disclosure and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.
In describing the invention, it will be understood that a number of techniques and steps are disclosed. Each of these has individual benefit and each can also be used in conjunction with one or more, or in some cases all, of the other disclosed techniques. Accordingly, for the sake of clarity, this description will refrain from repeating every possible combination of the individual steps. Nevertheless, the specification and claims should be read with the understanding that such combinations are entirely within the scope of the invention and the claims.
In one embodiment, a robotic grasping system is disclosed. In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the present invention. It will be evident, however, to one skilled in the art that the present invention may be practiced without these specific details.
The present disclosure is to be considered as an exemplification of embodiments, and is not intended to limit the scope of the invention to the specific embodiments illustrated by the figures or description below. Other embodiments may be implemented in many different forms and should not be construed as limited to the examples set forth herein.
Embodiments are now described by referencing the appended drawing figures.
In some constructions, the Z-dimension carriage or rail is mounted to the X-dimension carriage on the X-dimension rail that allows the Z-dimension rail to move side-to-side (the X-dimension). This forms a two-dimensional frame of the robot, which can move in the X- and Z-dimensions. The catching mechanism 26 is coupled to an end portion 70 of the Z-dimension rail and is capable of engaging with target objects 14 moving in the Y-dimension (front and back) despite the Z-dimension rail itself being unable to move in the Y-dimension and the X-dimension rail itself being unable to move in the Y-dimension.
More specifically, as seen in close-up view in the embodiment depicted in
Control of the X-dimension movement relies on a movement system 48 that may or may not be the same as the movement system 44 that manipulates the Z-dimension movement. Like the Z-dimension's movement system 44, the X-dimension movement system 48 may be operated by automated or manual controls.
The rail system 22 allows the catching mechanism 26 to be positioned at a predetermined height (Z-dimension) and predetermined longitude (X-dimension) to allow the end effector 30 to make initial contact with the target object 14 moving in the front and rear dimension (the Y-dimension) when the target object 14 passes under the catching mechanism 26. As such, the predetermined height and the predetermined longitude defines a predetermined position of the end effector 30. The end effector's 30 predetermined position may be determined in many ways including, but not limited to, an automated system or manual controls. For example, the robotic system 10 may include one or more sensors for determining the predetermined position of the end effector based on the movement of the target object. Other embodiments may not require Z-dimension and/or X-dimension movement.
The end effector 30 is configured to make initial contact with the target object 14, when the end effector 30 reaches the predetermined position. After the end effector reaches the predetermined position, the catching mechanism 26 allows the end effector 30 to move in the same direction D1 as the target object 14 (e.g., in the Y-dimension) for a duration through means such as (but not limited to) motorized movement, or being dragged by friction against the target object 14. For example, as further discussed below, in some embodiments as shown in
The catching mechanism 26 including the end effector 30 attached thereto is configured to allow the end effector 30 to move outside of the X-dimension and Z-dimension of the robot's frame. In other embodiments of this system, the Y-dimension catching mechanism may have a field of motion not defined by a linkage or rail system, such that it can move in one or more dimensions in order to make contact with moving target objects. In other embodiments of this system, the field of motion may be oriented in various dimensions or at various angles to allow the carriage to move in the same direction as the target object. Angles, in this context, are not necessarily in the Y-dimension or perpendicular to the Z-dimension pillar as depicted in this embodiment. In some embodiments of this system, the field of motion may not be linear (e.g., traveling in an arc). In some embodiments of this system, the catching mechanism may not require a field of motion at all, if it is able to successfully grasp the target object sufficiently quickly (e.g., by using very high-powered suction).
The catching mechanism's 26 free movement means that the end effector 30, after making initial contact with a target object 14, can move in the same direction D1 as the target object 14 for a long enough period of time to successfully pick up the target object 14 through suction, manual grasp, or the like. The size of the catching mechanism's 26 field of motion (for example, the length of the rail 34, 38, the range of movement of the linkage arms 50, the length of the linkage arms 50, etc.) can be determined based on the predetermined amount of time the end effector 30 must make sustained contact with a target object 14 to successfully grasp it; this is in turn is determined by variables including, but not limited to, the speed at which the target object 14 is moving, the material of the target object 14, and/or the shape of the target object 14.
In order to achieve a precise position to make initial contact with a target object 14, the end effector 30 is positioned in a first or known starting position (see
In some embodiments, the catching mechanism 26 is capable of being moved, through automated or manual controls, on a one- or two-dimensional robotic frame, to the predetermined position in order to make initial contact with a stationary or moving target object 14, such that the end effector 30 attached to the catching mechanism 26 may sustain contact with the target object 14 for enough time to successfully grasp the target object 14 during the period of contact, and such that the return mechanism is capable of returning the end effector 30 to its starting position if the end effector 30 has moved positions while picking up the target object 14. In some embodiments, the catching mechanism may be affixed to a stationary or moveable frame that allows the catching mechanism to move to a predetermined position to make contact with a target object. In some constructions, the catching mechanism 26 is attached to a robotic system for movement of the catching mechanism to a predetermined position. In some constructions, the robotic system is able to move in the Z-dimension (up and down) and/or the X-dimension (side-to-side).
In some constructions, the robot 10 is capable of moving in the Z dimension (up-and-down) and the X dimension (side-to-side) and is configured to move the catching mechanism 26 to the predetermined position to allow the end effector 30 to make initial contact with the target object 14 moving in the front and rear dimension (the Y-dimension) when the target object 14 passes under the catching mechanism 26. Once initial contact is achieved, the system 10 relies on friction created by this contact to move passively in the direction that the target object 14 is moving, and to sustain contact for a long enough period of time to achieve a successful grasp. After the object has been picked up, the system 10 uses the return mechanism whose purpose is to return the end effector 30 to the predetermined starting position. This design results in a system that is significantly smaller, lighter-weight, and less expensive than existing robotic designs used to pick up moving objects.
In one embodiment, as shown in
During the time of prolonged contact, the end effector 30 can pick up the object 14 successfully, whether by vacuum suction, manual grasp, or the like. In the illustrated embodiment, the end effector 30 is depicted as a suction cup attached to an airflow system 58 via a port 62. The end effector may have other embodiments, including but not limited to one or multiple suction cups, claws, spikes, jamming grippers, and so on. Other end effectors may use controls other than an airflow system, such as another motor. In the embodiment depicted in
Referring back to
With reference to
With reference to
Each of the springs 54 is configured to bias the end effector 30 toward the starting position.
In
In addition, the one or more stops, such as the plate 78 or another stop, is positioned between linkage arms 50 of the plurality of linkages to limit or prevent the linkage arms 50 from rotating about or around the hinge points 52, thereby preventing the linkage arms 50 from moving further in the X-dimension. In other embodiments, the catching mechanism's 26 field of movement may be defined in multiple dimensions and/or by means other than a hinge, and the stops may be other physical stops or digital stops such as a limit switch.
In operation, in the embodiment depicted in
The catching mechanism 26 moves back to its starting position, having successfully grasped the target object 14. This is achieved through activation of the return mechanism, which moves the end effector 30 back to its initial position. In the illustrated embodiment, the return mechanism includes the springs 54; as the robot 10 lifts the end effector 30 upwards, the tension existing in the springs 54 is no longer counteracted by friction moving the end effector 30 in the Y-dimension, so the spring 54 contract and return the end effector 30 back to its initial position. However, this depiction is not to be interpreted in a limiting sense; the return mechanism may have many other embodiments, including but not limited to a single spring, a motor, or an air pump. In some embodiments, the robot's 10 upward movement may not be necessary to enable the end effector 30 to move back to its starting position.
Once the catching mechanism 26 is at rest in its starting position, successfully grasping the target object 14, the target object 14 can now be placed where intended. In one example use case, the catching mechanism 26 can be moved to the side (the X-dimension) by movement of the Z-dimension rail 34 across the X-dimension rail 38, such that the target object 14 can be released to its intended destination. Examples of intended destinations may include, but are not limited to, a receptacle, a slide, another conveyor belt, and so on.
The electronic processor 102 obtains and provides information (for example, from the memory 104 and/or the communication interface 106), and processes the information by executing one or more software instructions or modules, capable of being stored, for example, in a random access memory (“RAM”) area of the memory 102 or a read only memory (“ROM”) of the memory 104 or another non-transitory computer readable medium (not shown). The software can include firmware, one or more applications, program data, filters, rules, one or more program modules, and other executable instructions. The electronic processor 102 is configured to retrieve from the memory 104 and execute, among other things, software related to the control processes and methods described herein. For example, the electronic processor 102 may be configured to to determine the position of target object or the end effectors. The memory 104 can include one or more non-transitory computer-readable media, and includes a program storage area and a data storage area. The program storage area and the data storage area can include combinations of different types of memory, as described herein.
The communication interface 106 is configured to receive input and to provide system output. The communication interface 106 includes hardware for communicating over one or more wired or wireless communication networks or connections with, for example, the one or more sensors for determining the predetermined position of the end effector.
The input/output interface 108 may include one or more input mechanisms (for example, a touch screen, a microphone, a keypad, buttons, knobs, and the like), one or more output mechanisms (for example, a display, a printer, a speaker, and the like), or a combination thereof. The input/output interface 108 receives input from input devices actuated by a user and, in some embodiments, the one or more sensors of the communication interface 106 provides output to output devices with which the user interacts.
The controller 100 may include one or more sensors (including the one or more sensors for determining the predetermined position of the end effector) to determine one or more characteristics of the system 10 and operate the system based on data from the one or more sensors. The one or more sensors may include, but are not limited to, image sensors, audio sensors, pressure sensors, position sensors, and the like. The electronic controller 100 may be configured to utilize the one or more sensors to determine target object features of the target object 14 (for example, via objection detection/recognition methods) and accordingly operate the system 10 similar to as is described above (for example, operate a particular robot to grip the object). The controller 100 may cause the robotic frame to move the end effector 30 to the predetermined position in order to make initial contact with a stationary or moving target object 14. The controller 100 may cause the airflow system 58 to begin vacuum suction prior to or at the moment of the suction cup's 30 initial contact with the target object 14, and to halt vacuum suction when the suction cup 30 is ready to release the object 14 at the intended destination.
Using the approach described above, a robotic system is able to pick objects from a moving belt 18′ despite having a significantly narrower profile and simpler frame than robotic systems utilized in prior art. Due to its smaller size and lower cost, the robotic system described herein is easier and cheaper to fabricate and install. As a result, it affords its users substantial savings in time, space, and cost compared to robotic systems described in prior art.
In one embodiment, a frame of a robot comprises two carriages, each attached to a rail. One carriage is capable of sliding up and down on a vertical rail (the Z-dimension); the carriage is attached to another carriage capable of sliding side to side on a horizontal rail (the X-dimension), which in practice allows the vertical rail to move both up-and-down and side-to-side. In this embodiment, the movement of both carriages is powered by motorized controls.
The length of the horizontal X-dimension rail can be determined by the sum of the width of the field in which target items may appear (for example, the width of a conveyor belt) and the distance to the drop-off point for the picked-up object.
The robotic system described above is able to (1) move the end effector to a position to make initial contact with a target object, (2) allow the end effector to travel alongside the target object if needed, such that it can make contact for a sustained enough period of time to achieve a successful grasp, (3) pick up the object once it has achieved a successful grasp, and (4) drop the object in a desired location.
The narrow profile of the embodiments shown herein affords the ability to sequentially install two or more such robots in the same amount of space that might be occupied by a single robot sorter of other types. The ability to install multiple sorting robots of the embodiments shown herein sequentially unlocks opportunities for novel sorting systems that can pick up a larger volume of objects and/or a more heterogeneous array of objects than attained by other robotic systems, while also providing space and cost savings over other robotic systems.
A basic embodiment of a multi-robot sorting system involves installing two or more sorting robots, as described above, sequentially along a conveyor belt. In this multi-robot embodiment, as in the single-robot embodiment described earlier, the controls that determine the position of the end effector(s) may be automatic or manual. In the case of automatic controls, a single centralized system may be capable of coordinating and optimizing the movements of the two or more robots. A multi-robot sorting system as described herein offers improved ability to pick up target objects traveling in the Y-dimension despite the robot itself being unable to move in the Y-dimension, because the usage of multiple catching mechanisms allow the multi-robot sorting system more instances to engage with a target object along the object's path of motion than a single robotic sorter alone. A multi-robot sorting system that uses robots of the design described above also affords cost and space savings over robotic sorting systems of the prior art.
With reference to
In some constructions, a system in which two or more robots 10 as described above are installed in sequence; in which the robots 10 may have as attachments different combinations of one or more types of end effectors 30 in different orders; and in which one or more of the robots 10 may be assigned to automatically or manually pick up a target object 14.
A multi-robot sorting system allows the use of more than one end effector. As a result, a full array of end effectors can be utilized within a multi-robot system, allowing the system to pick up significantly more types of objects. As in previously described embodiments, the controls that determine the position of the end effectors may be automatic or manual. If relying on automatic controls, a single centralized system may be capable of coordinating and optimizing the movements of the two or more robots. In one embodiment, a single centralized system, or electronic controller 100″, 100′″, uses a computerized algorithm to detect target object 14″, 14′″, features such as size, shape, material, and position. The target object features can be analyzed to determine which robot or robots within a multi-robot system should be assigned a task to pick up the target object 14″, 14′″. The assignment determination can be based on any number of considerations, including which end effector is best suited to grip the object, which robot is positioned to reach the object 14″, 14′″ the fastest, and so on.
In a multi-robot sorting system, regardless of the number of robots or the combination of end effectors used, the system relies on an external process (automated or manual) for selecting the robot best-suited to picking up a given target object. The selection of a best-suited robot may be determined by assessing such object-specific variables including but not limited to the object's size, shape, position, and material; and such robot-specific variables including but not limited to the robot's position in the sequence, the position of the robot's end effectors along the frame, or the design of the end effectors themselves.
Embodiments described above may rely on automated or manual controls to move the catching mechanism to the predetermined position. Embodiments may also use different combinations of motorized and passive movement to move the end effector. Example embodiments include, but are not limited to, three dimensions of controlled movement such that the end effector is movable to the predetermined position to allow initial grasping of the target object, and then sustain movement of the end effector alongside the target object in order to achieve a successful grasp. In other embodiments, two dimensions of controlled movement is provided to allow initial grasping of the target object, and then one dimension of passive movement is provided, in which the end effector is moved (e.g., pulled) in the direction of the target object by making initial contact with the object.
Although the invention has been described in detail with reference to certain preferred constructions, variations and modifications exist within the scope and spirit of one or more independent aspects of the invention as described.
This application claims benefit of co-pending U.S. Provisional Patent Application No. 63/130,076, filed on Dec. 23, 2020, the entire contents of which is incorporated herein by reference.
Number | Date | Country | |
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63130076 | Dec 2020 | US |