Patent Publication Number: US-2023159280-A1

Title: System and method for identifying and transporting non-conveyable items

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     The present application claims priority of U.S. provisional application Ser. No. 63/281,158 filed Nov. 19, 2021, which is hereby incorporated by reference herein in its entirety. 
    
    
     FIELD OF THE INVENTION 
     The present invention is directed to material handling systems, and in particular material handling conveyors. 
     BACKGROUND OF THE INVENTION 
     Material handling systems for warehouse, order-fulfillment facilities, common carriers, and the like, commonly handle items, products, packages, etc., having varying shapes, sizes, weights, configurations, and orientations. In some instances, packages may have a characteristic that creates issues for the material handling system. For example, an exceedingly long package may become stuck in a curved stretch of conveyor, the momentum of an exceedingly heavy object may cause damage to a guide on a conveyor, an item with a relatively high center of gravity (CG) may tip over a conveyor guide and fall off the conveyor system, etc. Round, non-symmetrical, and otherwise oddly shaped items and very lightweight items may create many different issues and problems within material handling systems. For example, the following issues may commonly occur within conveyance systems when handling oddly shaped items: “no-reads” in which label scanners are unable to read a label on a product; jams and faults due to the shape, weight, or orientation of a product; damage to equipment and/or guardrails, such as from falling or tipping products; and damage to products which may ultimately be sent on to a soon-to-be disappointed or upset customer. 
     SUMMARY OF THE INVENTION 
     The present invention provides a system and method for identifying and subsequently safely handling unstable or challenging products, which may be otherwise referred to as a non-conveyable product or item. The system and method are particularly beneficial for identifying non-conveyable items before they enter a more complex function of a material handling system, such as before they are inducted into a sortation system, for example. Once identified, non-conveyable items may be removed from the primary conveyance systems and handled with an appropriate level of care. Many commonly occurring issues or mishaps may be eliminated or greatly reduced by identifying and removing non-conveyable product from the system that are considered. For example, the system and method may facilitate a reduction in label no-reads, a reduction in jams and faults within conveyance systems, a reduction in damage to equipment and/or guardrails, and reduction in damage to products. Non-conveyable products or items may include, but are not limited to, items with high center of gravity (CG), and round, elliptical, spheroid, ellipsoid, octahedron, and/or non-symmetrical items, for example. 
     According to one form of the present invention, a method is provided for determining the conveyability of an item transported by a transportation or material handling system of a material handling facility and includes transporting a subject item with an upstream portion of the material handling system to an item assessment conveyor system. The assessment conveyor system is operable to convey an item at varying rates, including a constant rate, an accelerating rate, and a decelerating rate. The assessment conveyor system is operated at the constant rate and a sensor system positioned at the assessment conveyor system measures a dimension of a contact region between the subject item and the conveyance surface of the assessment conveyor system. This measurement may be referred to as a constant rate contact region dimension. The assessment conveyor system is then operated at the accelerating rate and the sensor system measures a dimension of the contact region between the subject item and the conveyance surface. This measurement may be referred to as an accelerating rate contact region dimension. The assessment conveyor system is then operated at the decelerating rate and the sensor system measures a dimension of the contact region between the subject item and the conveyance surface. This measurement may be referred to as a decelerating rate contact region dimension. 
     The method assesses whether the subject item is conveyable or non-conveyable as a function of the measured contact region dimensions. The computer determines a relative orientation change of the subject item by comparing two or more of the measured contact region dimensions (e.g. constant rate contact region dimension, accelerating rate contact region dimension, and/or decelerating rate contact region dimension). The relative orientation change(s) is compared with a user defined maximum orientation change threshold, which is selected by the user prior to operation of the system. If the relative orientation change is less than the user defined maximum orientation change threshold, the subject item is determined to be conveyable and is transported downstream toward a downstream function or process with a conveyable item handling function or system (e.g. a primary conveyor or transportation device that is capable of handling conveyable items) of the material handling system. However, if the relative orientation change is greater than the user defined maximum orientation change, the subject item is determined to be non-conveyable and is diverted away from the primary conveyor to an item handling function or system capable of handling non-conveyable items (e.g. a bulk item transportation system, such as a heavy duty conveyor system, an autonomous mobile robot (AMR), or a manually operated cart). 
     In one aspect, the assessment conveyor system includes a sequence or arrangement of consecutively spaced belt conveyors including a first belt conveyor, a second belt conveyor, and a third belt conveyor. The first belt conveyor is operable to convey an item at the constant rate, the second belt conveyor is operable to convey an item at the accelerating rate, and the third belt conveyor is operable to convey an item at the decelerating rate. In another aspect, the sensor system includes a first sensor at the first belt conveyor, a second sensor at the second belt conveyor, and a third sensor at the third belt conveyor. The constant rate contact region is measured by the first sensor, the accelerating rate contact region rate contact region is measured by second sensor, and the decelerating rate contact region is measured by the third sensor. In yet another aspect, at least one of the dimensions being measured for the constant rate contact region, accelerating rate contact region, and decelerating rate contact region each includes a dimension that is parallel to the forward direction of travel of the assessment conveyor system. 
     In another form of the present invention, an item conveyability assessment system is provided for determining whether an item is safely conveyable within a material handling system. The assessment system includes a variable rate conveyor system, in the form of a sequence or arrangement of consecutively spaced belt conveyors, such as a first belt conveyor, a second belt conveyor, and a third belt conveyor, for example. In such configurations, the first belt conveyor is at least operable at a constant conveyance rate, the second belt conveyor is at least operable at an accelerating conveyance rate, and the third belt conveyor is at least operable at a decelerating conveyance rate. A sensor system is provided with the assessment system to measure at least one dimension of a contact region between the item being conveyed and the conveyor surface. The sensor system may include a first sensor adjacent the first belt conveyor, a second sensor adjacent the second belt conveyor, and a third sensor adjacent the third belt conveyor. The sensors may utilize photoelectric arrays, cameras, or various other known sensor systems adapted for sensing or making measurements in one or more dimensions. Optionally, the sensor system measures a dimension of the contact region in the direction that is parallel to the forward direction of travel of the assessment conveyor system. 
     Accordingly, forms of the present invention provides a system and a method for automatically determining whether a particular item is stable or otherwise safe to handle within a material handling system. The system utilizes a variable rate conveyor system to convey the item, accelerate the item, and decelerate the item to determine if the item&#39;s orientation shifts due to momentum changes. If an item exhibits any orientation shifts greater than a user defined maximum value, the item is deemed non-conveyable and is removed from the primary portion of the material handling system. Thereby, the method and system may reduce or eliminate faults within the material handling system and/or reduce or eliminate damage to the system or item that may be caused by the item shifting during its conveyance. 
     These and other objects, advantages, purposes and features of this invention will become apparent upon review of the following specification in conjunction with the drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a top perspective view of an item assessment conveyor system, in accordance with the present invention; 
         FIG.  2    is a side elevation view of a variable rate portion of the item assessment conveyor system of  FIG.  1   , depicting items being conveyed at different conveyance rates relative to one another; 
         FIG.  3    is a side elevation view of the item assessment conveyor system of  FIG.  1   , depicting an item being conveyed at an accelerating conveyance rate; 
         FIG.  4    is another side elevation view of the item assessment conveyor system of  FIG.  1   , depicting an item being conveyed at a decelerating conveyance rate; and 
         FIG.  5    is a diagram of a method for determining the conveyability of an item, in accordance with the present invention. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring now to the drawings and the illustrative embodiments depicted therein, an item conveyability determination or assessment conveyor system  10  and a method  100  are provided for determining the conveyability of an item or package  12  in a material handling system  14 , such as items being handled in a warehouse, order fulfillment facility, or other material handling facility. In particular, the system  10  and method  100  are particularly well-suited for identifying and appropriately transporting “non-conveyable” items or packages  12 , which may include such items as round, elliptical, spheroid, ellipsoid, octahedron, and/or non-symmetrical items, items with insufficient weight to maintain sufficient contact with a conveying surface whereby the conveying surface may slip or slide underneath the item, items with an unstable center of gravity (CG), and otherwise oddly shaped or difficult to handle items. The system  10  utilizes a sensor system  16  to determine or measure a contact area between an item being conveyed and the conveyor surface that is conveying the item. It is contemplated that the system  10  may be utilized at any desired position within a facility. For example, the system  10  may be provided at a receiving subsystem to assess the conveyability of all items as they are received into the facility. As such, the system  10  and method  100  may filter out all non-conveyable items before they enter the primary or main conveyance components within the facility, thereby limiting potential problems or mishaps caused by non-conveyable items. The system  10  may be provided within new or existing facilities, such as in a retrofit manner. 
     Referring to the illustrative embodiments of  FIG.  1 - 4   , the item assessment conveyor system  10  defines a portion of the material handling system  14  and includes an arrangement or sequence of consecutive belt conveyors, including a first belt conveyor  18 , a second belt conveyor  20 , and a third belt conveyor  22  to transport items at variable or changing rates relative to one another. The conveyor system  10  is configured to receive items from an upstream process, such as an upstream conveyor or conveyance system or an autonomous mobile robot (AMR), for example. A sensor system is provided with the system  10  and is defined by a set of photo arrays  24 ,  26 , and  28  positioned in proximity or adjacent to respective belt conveyors  18 ,  20 , and  22 . The material handling system  14  includes a primary or main conveyor  30  downstream of the third belt conveyor  22 . The primary conveyor  30  directs or handles conveyable items toward downstream functions of the material handling system  14 , such as sorters, storage systems, packing stations, pick or decant workstations, and the like. A divert system, in the form of a steerable wheel or ball transfer diverter  32 , is provided along the primary conveyor  30  and is operable to divert non-conveyable items  12  away from the primary conveyor  30  to a secondary item handler, as depicted in the form of a belt conveyor  33 , prior to entering the remainder of the material handling system  14 . The secondary item handler conveyor  33  or other transportation systems and any functions or processes downstream of handler  33  are capable of safely handling non-conveyable items. Examples of suitable secondary item handler conveyors or transportations systems include bulk item transportation systems, such as heavy duty conveyor systems, autonomous mobile robots (AMR), and manually operated carts. 
     The material handling system  14  is controlled by a warehouse management system that includes a computer device  35  that is programmed with computer code that is adapted to control the various components of the system, including the belt conveyors  18 ,  20 , and  22  and the photo arrays  24 ,  26 , and  28 . The computer  35  of the system  14  may comprise one or more processors as well as hardware and software, including for performing the operations discussed herein. Each belt conveyor  18 ,  20 , and  22  includes a respective conveying surface  34 ,  36 , and  38  upon which items  12  are supported and transported ( FIGS.  1 - 4   ). Each belt conveyor  18 ,  20 , and  22  is selectively operable to convey items at constant and/or variable rates. For example, the belt conveyors may operate at different rates relative to one another. For instance, the first belt conveyor  18  may be configured to convey items downstream at a constant conveyance rate or speed, the second belt conveyor  20  may be configured to convey items at an accelerating or increasing conveyance rate or speed, and the third belt conveyor may be configured to convey items at a decelerating of decreasing conveyance rate or speed. The accelerating rate and the decelerating rate may be abrupt or rapid enough to change the momentum of an item conveyed thereon and cause it to shift, rock, or tilt. As such, the area or region of the item in contact with the conveying surface may change as compared to when the item is traveling at a constant conveyance rate, for example. 
     It will be appreciated that while the system  10  is depicted with a sequence of three belt conveyors  18 ,  20 , and  22 , that more or fewer belt conveyors may be utilized, without significantly affecting the functionality of the system  10 . For instance, multiple belt conveyors may not be required in all instances and a single variable rate belt conveyor may be sufficient to perform the method  100  (as described in detail below) by performing multiple steps with the single belt conveyor. For example, a single belt conveyor may operate initially at a constant rate, then an accelerating rate, and then a decelerating rate to perform method  100  before conveying the item  12  to the primary conveyor  30 . Alternatively, in another example, a single belt conveyer may operate initially at an accelerating rate, then at a decelerating rate, and then at a constant rate to perform method  100  before conveying the item to the primary conveyor  30 . While it is preferable to transport an item continuously in a forward direction (i.e. without reversing the transport direction of the item) at all times to maintain a constant, substantially uninterrupted forward flow of items moving along the system  10 , it will be appreciated that the conveyor may be operated in reverse in some instances, which may enable or facilitate gathering additional conveyability information for an item. 
     The photo arrays  24 ,  26 , and  28 , are each positioned nearby, adjacent, or along their respective belt conveyor such that they are operable to sense or recognize a point, area, or region of contact between (i) an item conveyed by the respective conveyor and (ii) the conveying surface of the respective conveyor. The photo arrays  24 ,  26 , and  28  are operable to sense the point, area, or region of contact in at least one dimension. In the illustrative embodiments, as best depicted in  FIG.  2   , the photo arrays perceive the item  12  and respective conveying surface  34 ,  36 , or  38  from a location perpendicular to the forward direction of travel of the assessment conveyor system  10  such that the dimension to be sensed is parallel to the forward direction of travel of the assessment conveyor system  10 . The dimension sensed by each photo array at the respective belt conveyor  18 ,  20 , and  22  is representative of an item&#39;s  12  contact area relative to the respective conveying surface  34 ,  36 , or  38 . In other words, the photo array may sense that an item  12  is in contact with the respective conveying surface for a dimension of five inches (5 in.) in the direction parallel to the forward direction of travel. That five inch measurement is representative of the amount of contact between the item and the conveying surface in that one dimension of view only, and in most instances does not indicate that the item touches the conveying surface only along a five inch line. While the sensing system may be operable to recognize or sense points, areas, or regions of contact in more than one dimension, the system  10  is well suited for determining whether an item is non-conveyable based on measurements in only a single dimension. The photo arrays  24 ,  26 , and  28  may utilize various types of photo arrays or photo sensors, including photoelectric sensors, for example (e.g. thru-beam sensors, retroreflective sensors, diffused sensors, laser photoelectric sensors, fiber optics photoelectric sensors, or remote photoelectric sensors). While the sensor system as described herein for the illustrative embodiment utilizes photo arrays, it will be appreciated that other forms of sensors may be utilized including image-based camera system sensors, radio frequency identification (RFID) sensors, ultrasonic sensors, infrared sensors, LiDAR sensors, time of flight (ToF) sensors, and the like. The system  10  may assess other physical characteristics of the item  12 , such as determining the weight of the item. For example, the system  10  may include a scale integrated with a conveyor (e.g. one of the belt conveyors) of the system  10  to determine the weight of an item as it is conveyed. Alternatively, the weight may be determined by scanning a label on the item and accessing a database of inventory item information to retrieve the item&#39;s information (e.g. weight) based on the scanned label. 
     While the divert system of the illustrative embodiment is depicted as a steerable wheel or ball transfer  32 , it will be appreciated that any commonly known or readily available divert system may be utilized without substantially affecting the function of the system  10 . For example, the divert system may utilize a right angle transfer (RAT) to divert the item  12  from the primary or main conveyor  30  or, alternatively, an operator (human or robot) may manually retrieve the non-conveyable item  12  from the primary conveyor  30 . 
     Referring to the illustrative embodiment of  FIG.  5   , a method  100  is provided for determining the conveyability of an item  12  being transported by a facility&#39;s material handling system  14 . The method  100  includes transporting  102  a subject item  12  with an upstream portion of the material handling system  14  to an item assessment conveyor system, such as assessment system  10  described above and illustrated in  FIGS.  1 - 4   . The assessment system  10  is operable to convey an item  12  at varying rates, including a constant conveyance rate, an increasing or accelerating conveyance rate, and a decreasing or decelerating conveyance rate. Initially, the computer of the warehouse management system operates  104  the assessment system  10  at the constant conveyance rate and measures  106 , with photo array  24  of the assessment system  10 , a representative dimension Rc of a constant rate contact region of the item  12  (see Rc at belt conveyor  18  of  FIG.  2   ). The constant rate contact region is defined as the region where the item  12  being conveyed on the assessment system  10  is in contact with the conveyance surface (e.g. surface  34 ) of the assessment system under a constant conveyance rate. The constant rate may be provided by moving the conveyor surface in either of the forward direction, or the reverse direction, at a constant rate, for example. Subsequently, the computer operates  108  the assessment system  10  at the accelerating conveyance rate and measures  110 , with photo array  26  of the assessment system  10 , a representative dimension Ra of an accelerating rate contact region (see Ra at belt conveyor  20  of  FIGS.  2  and  3   ). The accelerating rate contact region is defined as the region where the item  12  being conveyed is in contact with the conveyance surface (e.g. surface  36 ) of the assessment system under an accelerating conveyance rate. The accelerating rate may include increasing the speed of the conveyer surface in the forward direction of travel, or with the item stationary on the conveyance surface, the conveyor may accelerate in a reverse direction, for example. Next, the computer operates  112  the assessment system  10  at the decelerating rate and measures  114 , with photo array  28  of the assessment system  10 , a representative dimension Rd of a decelerating rate contact region (see Rd at belt conveyor  22  of  FIGS.  2  and  4   ). The decelerating rate contact region is defined as the region where the item  12  being conveyed is in contact with the conveyance surface (e.g. surface  38 ) of the assessment system under a decelerating conveyance rate. The decelerating rate may include decreasing the speed of the conveyer surface in the forward direction of travel, for example. 
     It will be appreciated that due to the physical characteristics of an item and its propensity to shift or experience a relative change in orientation during momentum changes (i.e. the item&#39;s contact region changes as the item accelerates and/or decelerates), the item&#39;s respective contact region dimensions Rc, Ra, and/or Rd may all be different from one another, may all be equal to one another, or two may be equal while the third is different than the equal two. 
     Based on the measured contact region dimensions Rc, Ra, and/or Rd, the method  100  assesses  116  whether the subject item has undergone a relative orientation change or has remained relatively stable ( FIG.  5   ). The accessing or assessment  116  requires determining at  118  if there has been a relative orientation change of the subject item by comparing, with the computer, two or more of the measured contact region dimensions Rc, Ra, and/or Rc. In other words, the assessment  116  is based on whether one or both of the accelerating rate contact region dimension Ra and the decelerating rate contact region dimension Rd is/are different than the initial constant rate contact region dimension Rc. The method  100  includes comparing  120  the relative orientation change with a user defined maximum orientation change threshold. The user defined maximum orientation change value is chosen by the user or operator as a function what they deem is an acceptable amount of relative orientation change of an item to be safely handled by the main conveyor  30  of the material handling system  14 . In other words, a user may consider that items exhibiting a relative orientation change of a certain value or above would cause jams or faults within the material handling system  14 , and that any such item should be defined as a non-conveyable item and excluded from transport by the main conveyor  30 . The method includes determining  122  whether the measured relative orientation change is greater than or equal to the user-defined maximum value ( FIG.  5   ). It may be determined at  118  that there has been no relative orientation change of the item and the item is therefore be deemed at  124  conveyable and continues on to be transported  126  along the primary conveyor  30  ( FIG.  5   ). Likewise, if it is determined at  118  that there has been some relative orientation change of the item but that the relative orientation change is less than the user defined maximum orientation change, the item  12  is deemed at  124  to be conveyable, and it continues on to be transported  126  along the primary conveyor  30 . However, if it is determined at  118  that there has been a relative orientation change of the item  12  and that the relative orientation change is greater than the user defined maximum orientation change, the item  12  is deemed at  128  to be non-conveyable, and the computer controls the diverter  32  to divert  130  the non-conveyable item to a non-conveyable item handler  33  ( FIG.  5   ). 
     In view of the illustrative embodiments of  FIGS.  1 - 5   , the measuring  106  of the constant rate contact region dimension includes measuring the dimension with the first sensor  24  positioned adjacent the first belt conveyor  18 . Measuring  110  the accelerating rate contact region dimension includes measuring the dimension with the second sensor  26  positioned adjacent the second belt conveyor  20 . And measuring  114  the decelerating rate contact region dimension includes measuring the dimension with the third sensor  28  positioned adjacent the third belt conveyor  22 . However, it will be appreciated that in an embodiment with only a single, variable rate belt conveyor, the measuring steps of  106 ,  110 , and  114  are performed with the same photo array (or other sensor system) that is positioned adjacent the single variable rate belt conveyor. 
     The following provides an example of the operation of the item assessment conveyor system  10 . A user or operator determines what constitutes a conveyable item and what constitutes a non-conveyable item. For example, the user defines that any item exhibiting a change in orientation, as a function of a contact area change (between item and conveyor surface) due to changes in item momentum, of greater than or equal to four inches ( 4  in.) under either of an acceleration or deceleration indicates that an item is unsafe or unstable to be transported in the subject material handling system  14  and is therefore non-conveyable. Any item exhibiting a contact area change of less than four inches is determined safe and/or stable and therefore conveyable with the main conveyor  30  of the material handling system  14 . A subject item  12  is conveyed with the first belt conveyor  18  at a constant rate and the first photo array  24  measures the dimension Rc of the contact region between the item  12  and conveyor surface  34  in the direction parallel to the forward direction of conveyance. The constant rate contact region dimension Rc is determined to be ten inches (10 in.). The item  12  is then conveyed with the second belt conveyor  20  at an accelerating rate and the second photo array  26  measures the dimension Ra of the contact region between the item  12  and conveyor surface  36  in the direction parallel to the forward direction of conveyance. The accelerating rate contact region dimension Ra is determined to be three inches (3 in.). The item  12  is then conveyed with the third belt conveyor  22  at a decelerating rate and the third photo array  28  measures the dimension Rd of the contact region between the item  12  and conveyor surface  36  in the direction parallel to the forward direction of conveyance. The decelerating rate contact region dimension Rd is determined to be eight inches (8 in.). As such, the change in contact region between the constant rate and the accelerating rate equals seven inches (7 in.) and the change in contact region between the constant rate and the decelerating rate equals two inches (2 in.). Therefore, because the change in contact region between constant and accelerating rates is greater than the user-defined maximum of four inches (i.e. 7 in.&gt;4 in.), the item  12  is deemed non-conveyable and is diverted from the main conveyor  30 . It will be appreciated that a change between the accelerating rate and the decelerating rate may be considered as well, or in the alternative, to determine conveyability of the item. 
     Thus, the item assessment conveyor system  10  and method  100  utilize varying conveyance rates to shift the momentum of an item being conveyed by the system, and based on any recognized changes in orientation of the item caused by momentum shifts, determining whether an item is stable or not. If an item is very unstable, or unstable to a level deemed unsatisfactory or unsafe, that item is deemed non-conveyable and diverted or otherwise removed from the system before it is transported downstream where it may affect the operation of the system or cause damage to the system or item. The system utilizes photo arrays, or other dimension sensing systems, to measure or detect dimensions of the contact region between the item being conveyed and the conveying surface. Dimensions of the contact region are measured under constant conveyance rates, accelerating conveyance rates, and decelerating conveyance rates to determine whether the item is conveyable or not. A user-defined value or threshold is pre-determined and represents the maximum allowable momentum shift (as a function of contact region dimension changes) is permitted to deem an item safe for conveying with the material handling system. The measured contact region changes are compared to the user-defined maximum change threshold, and if an item exhibits a contact region change greater than the maximum, the item is deemed non-conveyable. 
     Changes and modifications in the specifically described embodiments can be carried out without departing from the principles of the present invention which is intended to be limited only by the scope of the appended claims, as interpreted according to the principles of patent law including the doctrine of equivalents.