The present disclosure relates to industrial processing, and in particular to soft inflatable actuators suitable for performing various tasks, such as materials sorting.
Prior sorting systems, for example pneumatic piston actuators, have suffered from various drawbacks, including limitations due to high cost, limited life cycle, propensity for damaging items being sorted, and difficulty and expense to repair. Accordingly, improved sorting systems remain desirable.
Systems, methods, and devices for sorting utilizing an inflatable actuator are disclosed. In an exemplary embodiment, a sorting system utilizing an inflatable actuator may include an inflatable actuator. The inflatable actuator may be disposed in a cantilever beam orientation atop a support surface. The system may include an inflation component coupled to the inflatable actuator to provide an inflation force. Additionally, the system may include a control component configured to send an activation signal to the inflation component responsive to a detection of an object to be sorted. Responsive to the activation signal, the inflation component may inflate the inflatable actuator to cause the inflatable actuator to make contact with the object to be sorted. The contact of the inflatable actuator with the object to be sorted may cause the object to change from a first trajectory to a second trajectory.
In an exemplary embodiment, a method for sorting objects may include detecting, in a conveying system, an object to be sorted from a first trajectory to a second trajectory. The method may also include transmitting, from a control component to an inflation component coupled to an inflatable actuator, a control signal to cause the inflation component to transmit an inflation substance to the inflatable actuator. Additionally, the method may include inflating, by the inflation component, the inflatable actuator to bring the inflatable actuator into contact with the object to be sorted to cause the object to transition from a first trajectory to a second trajectory different from the first trajectory.
With reference to the following description and accompanying drawings:
The following description is of various exemplary embodiments only and is not intended to limit the scope, applicability, or configuration of the present disclosure in any way. Rather, the following description is intended to provide a convenient illustration for implementing various embodiments, including the best mode. As will become apparent, various changes may be made in the function and arrangement of the elements described in these embodiments without departing from principles of the present disclosure.
For the sake of brevity, conventional techniques for robotics, automated sorting, or both, including actuators, joints, power, control, a combination of these, or the like may not be described in detail herein. Furthermore, the connecting lines shown in various figures contained herein are intended to represent exemplary functional relationships, physical couplings between various elements, or both. It should be noted that many alternative or additional functional relationships or physical connections may be present in a soft actuator sorting system, components thereof, or both.
Principles of the present disclosure contemplate the use of soft inflatable actuators for use in connection with sorting processes. Prior approaches for sorting, for example sorting of high-volume products such as vegetables on a conveyor belt, typically involve the use of pneumatically driven actuators that remove undesirable products from the belt. These actuators are fabricated using mechanical components that are expensive, have limited life cycle, may have a propensity to damage the items to be sorted, and are hard to repair. For example, current setups in high volume sorting utilize actuators that perform a “flicking” motion to segregate the desirable products from the undesirable ones. These actuators typically include a mechanical assembly made up of a rigid link attached to a single-acting (spring-loaded) pneumatically actuated piston which actuates rapidly upon detection of a target. The rapid actuation of the piston to perform the flicking motion may damage the product being sorted or may rapidly deteriorate the piston or other components. These components may be difficult to repair or have other issues as described herein.
In order to remedy these and other deficiencies of prior approaches, exemplary inflatable actuator systems may be utilized.
In the illustrated example of
With reference now to
Exemplary soft-inflatable actuators 120 may be configured to perform a similar flicking action as prior mechanical actuators. Because the inflatable actuators 120 may be soft, at least when deflated, during at least a portion of the inflation, or both when deflated and during at least a portion of the inflation, the flicking action of the inflatable actuators 120 may be less likely to cause damage to items to be sorted.
In exemplary embodiments, various materials that are elastic and melt-processable may be used to form a soft-inflatable actuator 120. For example, soft-inflatable actuators 120 may be fabricated from suitable materials, for example heat-sealable film such as heat-sealed thermoplastic polyurethane material or any other type of heat sealable film such as polyester, PET, plastic film, or other heat-sealable films. The heat-sealable film may be encased in an inextensible fabric. The inextensible fabric may be any type of inextensible fabric. Examples of inextensible fabric include, but are not limited to, nylon fabric, polyester, rayon, or Kevlar, to name a few.
When an inflatable actuator 120 is in a resting (uninflated) state, the inflatable actuator 120 may be flexible and may exert very little or no force on objects, e.g., pellet 150, being sorted. For example, the pellet 150 may not contact the inflatable actuator 120 at all when the inflatable actuator 120 is not inflated. Alternatively, the pellet may slightly contact the inflatable actuator 120 when the inflatable actuator 120 is not inflated. For example, the pellet 150 may brush against the inflatable actuator 120. Furthermore, the inflatable actuator 120 may be in a different position, orientation, or both when the inflatable actuator 120 is inflated as compared to the position, orientation, or both of the inflatable actuator 120 when the inflatable actuator 120 is uninflated. Accordingly, the pellet 150 may still be directed in a different direction even if the pellet 150 contacts the uninflated inflatable actuator 120.
Because the inflatable actuator 120 exerts little or no force on the pellet, the inflatable actuator 120 may be effectively fully compliant to external disturbances. Upon the application of rapid internal pressurization, the inflatable actuator 120 may take up or assume a stiffened state. The inflatable actuator 120 may have a cross-section defined by the size and weight of the goods desired to be sorted. Accordingly, the inflatable actuator 120 may alter the trajectory of the pellet 150 when the pellet heads towards the inflatable actuator 120 by exerting an impact force.
Based on the specific sorting needs, the inflatable actuator 120 may be placed in different starting or resting angles. For example, the inflatable actuator 120 may be placed in a cantilever beam orientation. In a cantilever beam orientation, the inflatable actuator 120 may be fixed at one end and supported midway along the inflatable actuator 120 using another surface or fixture. In such setups, the unsupported part of the inflatable actuator 120 may be under the influence of gravity and may hang freely when uninflated.
When rapidly inflated, the inflatable actuator 120 stiffens and straightens out to a new orientation with respect to the ground plane while performing a forceful swinging/flicking motion. The swinging/flicking motion may impact the object, e.g., pellet 150, that comes in contact with the inflatable actuator 120 (for example, as illustrated in
In one exemplary embodiment, the inflatable actuator 120 may be fabricated as discussed above with a diameter of about 1.2 cm and a length of about 15 cm. The inflatable actuator 120 may be mounted in a cantilever beam orientation, fixed at the midpoint. On the application of an instantaneous internal pressure of about 300 kPa, the overhung inflatable actuator 120 overcomes gravity, performing a flicking motion to impart a force to an object or objects in inflatable actuator 120's path. This exemplary embodiment of the inflatable actuator 120 may be sized to sort cylindrical pellets having a diameter of about 1.5 cm, length of about 3.5 cm, and mass of about 20 grams. It will be appreciated that various embodiments of inflatable actuator 120 may be sized, scaled, or both sized and scaled to accommodate various sizes, shapes, and masses of objects to be sorted. For example, the inflatable actuator 120 may be fabricated with a diameter of between about 0.75 cm and about 10 cm. Moreover, the inflatable actuator may be fabricated with a length of between about 5 cm and about 50 cm.
It will be appreciated that exemplary inflatable actuators 120 may be used stand-alone (i.e., a single inflatable actuator 120) or in combination with multiple inflatable actuators 120. Inflatable actuators 120 may be utilized, for example, in connection with a conveyor belt, machine vision systems, temperature sensors, RFID systems, a combination of these or the like, to identify objects (for example, pellets 150) for sorting, for example based on an unacceptable/acceptable (pass/fail) criteria approach. Alternatively, inflatable actuators 120 may be utilized in connection with graded approaches whereby items meeting a first grade may be sorted by a first actuator (e.g., the inflatable actuator 120) and/or into a first trajectory, and items meeting a second grade may be sorted (by a first actuator 120, a second actuator 120, and/or the like) into a second trajectory, and so forth.
As compared to prior approaches for sorting, the exemplary inflatable actuator 120 based systems may utilize fewer mechanical moving components, have low cost, may be easy to replace, may have low maintenance cost, may take less time to maintain, and may be compatible with current industrial setups.
In an example embodiment, the inflatable actuator 120 may be tapered. For example, the inflatable actuator 120 may become gradually narrower or thinner toward one end of the inflatable actuator 120. In one example, the distal end may be narrower or thinner. In another example embodiment, the proximal end may be narrower or thinner. In yet another example embodiment, the tapering may run perpendicular to the long axis of the inflatable actuator 120. Accordingly, the inflatable actuator 120 may form a flatter surface, rather than a rounded surface, in such an example.
In an example embodiment, the inflatable actuator 120 has at least one of a circular, ovoid, rectangular, triangular, or superellipse (squircle) cross-section. For example, in an embodiment, the inflatable actuator 120 may have a circular or generally circular cross-section. The cross-section may be defined by cross-section that is generally equidistant or approximately equidistant from a central point within the cross-section of the inflatable actuator 120. In an example embodiment, the inflatable actuator 120 may have an ovoid or approximately ovoid cross-section such that the cross-section may generally be egg-shaped. In another example embodiment, the inflatable actuator 120 may have a rectangular or approximately rectangular cross-section. In an example embodiment, the inflatable actuator 120 may have a triangular cross-section. In another example embodiment, the inflatable actuator 120 may have a superellipse (squircle) cross-section.
A superellipse is a closed curve resembling an ellipse, retaining the geometric features of semi-major axis and semi-minor axis, and symmetry about them, but having a different overall shape from an ellipse. The set of all points (x, y) in the Cartesian coordinate system that from a superellipse satisfy the equation:
where n, a, and b are positive numbers, and the vertical bars | | around a number indicate the absolute value of the number.
A squircle is a shape intermediate between a square and a circle. There are at least two definitions of “squircle” in use, the most common of which is based on the superellipse. Another example of a squircle may be the Fernandez-Guasti squircle. As used herein, “superellipse (squircle)” may refer to the first definition based on the superellipse. However, in another example embodiment, the inflatable actuator 120 may have a Fernandez-Guasti squircle shape. Furthermore, the shapes listed for the inflatable actuator 120 are only intended to be examples. It will be understood that the inflatable actuator 120 may come in almost any shape that a tube (or other sealed or sealable shape) of heat-sealable film or other substances may be formed into as long as that shape may be encased in an inextensible fabric.
Generally, the shape of the inflatable actuator 120 may be a function of what is being sorted, including the object to be sorted's size, shape, weight, velocity of travel, or any other physical attribute of the object to be sorted that may impact the inflatable actuator 120's ability to sort the object. In other words, the inflatable actuator 120 may be tailored to the objects being sorted.
As discussed above with respect to
In another example embodiment, an inflatable actuator may be supported from an end only. Thus, when inactive, virtually all or at least a substantial portion of the inflatable actuator may hang vertically. (For example, as may occur if the cantilever support is removed in
Referring to
As discussed above,
While
Furthermore, the paddle 304, the soft-rigid hybrid actuator 302, or both the paddle 304 and the soft-rigid hybrid actuator 302 of the exemplary inflatable actuator system 300 may be configured to sort the other objects. As discussed above, with respect to other example embodiments, variations of impact angle, size, and shape of the soft-rigid hybrid actuator 302, the required pressure or pressure used by the soft-rigid hybrid actuator 302, the actuation speeds of the soft-rigid hybrid actuator 302, and the retracting of the soft-rigid hybrid actuator 302 to the resting position, may be defined based on attributes of the goods to be sorted. For example, the type of goods to be sorted, the size of the goods to be sorted, the shape of the goods to be sorted, the velocity of the goods to be sorted, or other attributes of the goods to be sorted may all influence selection of impact angle, size, and shape of the soft-rigid hybrid actuator 302, as well as the required pressure or pressure used by the soft-rigid hybrid actuator 302, the actuation speeds of the soft-rigid hybrid actuator 302, and the retracting of the soft-rigid hybrid actuator 302 to the resting position. Furthermore, the type of goods to be sorted, the size of the goods to be sorted, the shape of the goods to be sorted, the velocity of the goods to be sorted, or other attributes of the goods to be sorted or some combination of these may also influence selection of the size, shape, material, other attributes of the paddle 304.
As discussed above, the example method for sorting objects, e.g., pellets 150, includes detecting, in a conveying system, an object to be sorted from a first trajectory 130 to a second trajectory 190 (step 502). Detecting in an example sorting system may include using machine vision systems, temperature sensors, RFID systems, object weight, a combination of these or the like, or any other automated or semi-automated inspection technique to identify objects (for example, pellets 150) for sorting, for example based on an unacceptable/acceptable (pass/fail) criteria approach to determine which objects to send along the first trajectory 130 or the second trajectory 190. The inspections may take place along a conveying system such as a conveyer belt, track, or any other type of mechanical handling equipment that moves materials from one location to another. Alternatively, inflatable actuators 120 may be utilized in connection with graded approaches whereby items meeting a first grade may be sorted by a first actuator (e.g., the inflatable actuator 120) and/or into a first trajectory, and items meeting a second grade may be sorted (by a first actuator 120, a second actuator 120, and/or the like) into a second trajectory, and so forth.
The example method for sorting objects may also include transmitting, from a control component 180 to an inflation component 170 coupled to an inflatable actuator 120, a control signal to cause the inflation component to transmit an inflation substance to the inflatable actuator (step 504). For example, the control component 180 may transmit a signal to an inflation component 170. The signal transmitted to the inflation component 170 may cause the inflation component 170 to transmit or convey an inflation substance such as a gas, e.g., air, nitrogen, another gas or a mix of gasses; or a liquid, e.g., water, or other liquid; or mixture of liquid to the inflatable actuator 120. In an example embodiment, the inflation substance may be a mix of one or more gasses and one or more liquids.
Additionally, the example method for sorting objects includes inflating, by the inflation component 170, the inflatable actuator 120 to bring the inflatable actuator 120 into contact with the object to be sorted to cause the object to transition from a first trajectory to a second trajectory different from the first trajectory (step 506). For example, as discussed above, an inflation substance such as a gas, e.g., air, nitrogen, other gas or a mix of gasses; or liquid, e.g., water, or other liquid, or a mixture of liquids may be transmitted to the inflatable actuator 120. Accordingly, the inflatable actuator 120 may be inflated with the inflation substance, e.g., gas or liquid.
In an exemplary embodiment, the inflatable actuator may be disposed in a cantilever beam orientation atop a support surface, and wherein, when the inflatable actuator is uninflated, a portion of the inflatable actuator hangs off the support surface in a generally vertical orientation.
While the principles of this disclosure have been shown in various embodiments, many modifications of structure, arrangements, proportions, the elements, materials, and components, used in practice, which are particularly adapted for a specific environment and operating requirements may be used without departing from the principles and scope of this disclosure. These and other changes or modifications are intended to be included within the scope of the present disclosure.
The present disclosure has been described with reference to various embodiments. However, one of ordinary skill in the art appreciates that various modifications and changes can be made without departing from the scope of the present disclosure. Accordingly, the specification is to be regarded in an illustrative rather than a restrictive sense, and all such modifications are intended to be included within the scope of the present disclosure. Likewise, benefits, other advantages, and solutions to problems have been described above with regard to various embodiments. However, benefits, advantages, solutions to problems, and any element(s) that may cause any benefit, advantage, or solution to occur or become more pronounced are not to be construed as a critical, required, or essential feature or element.
As used herein, the terms “comprises,” “comprising,” or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Also, as used herein, the terms “coupled,” “coupling,” or any other variation thereof, are intended to cover a physical connection, an electrical connection, a magnetic connection, an optical connection, a communicative connection, a functional connection, and/or any other connection. When language similar to “at least one of A, B, or C” or “at least one of A, B, and C” is used in the specification or claims, the phrase is intended to mean any of the following: (1) at least one of A; (2) at least one of B; (3) at least one of C; (4) at least one of A and at least one of B; (5) at least one of B and at least one of C; (6) at least one of A and at least one of C; or (7) at least one of A, at least one of B, and at least one of C.
This application claims priority to, and the benefit of, U.S. Provisional Application Ser. No. 62/734,770 filed on Sep. 21, 2018, and entitled “SOFT INFLATABLE ACTUATORS FOR SORTING APPLICATIONS.” The above application is hereby incorporated by reference in its entirety.
Number | Date | Country | |
---|---|---|---|
62734770 | Sep 2018 | US |