Abstract:
Disclosed are a system and a method for sorting a parcel, and more particularly, a system for sorting a parcel that arranges articles to an outlet edge for each corresponding destination. 
     The system for sorting a parcel, which moves an article to a cart according to destination information of the article to classify the article to a chute for each destination, includes: an article position detecting unit which detects positional information of the article loaded on the cart that moves in a first direction by a track which moves in the first direction; and a control unit which controls the cart to rotate in a second or third direction according to the detected positional information of the article and destination information of the article.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority to and the benefit of Korean Patent Application No. 10-2014-0013119 filed in the Korean Intellectual Property Office on Feb. 5, 2014, the entire contents of which are incorporated herein by reference. 
       TECHNICAL FIELD 
       [0002]    The present invention relates to a system and a method for sorting a parcel, and more particularly, to a system for sorting a parcel that arranges articles at an outlet edge for each corresponding destination. 
       BACKGROUND ART 
       [0003]    With the growth of a delivery service industry, parcels are increased yearly. As a result, a post office or a distribution center uses a parcel sorting system in order to efficiently classify mail. In recent years, new sorting devices including a cross belt type, an E-Tray type, and the like have been developed and commercialized in order to increase an article processing capacity, and developed to sort small-sized articles and large-sized articles. However, since a parcel sorter has a high speed and article sizes vary, it is not easy to accurately locate the articles at the center of a cart when the articles are put in the cart. In addition, a fast track speed and an article position on the cart are not constant, thereby leading to an increase in a missorting occurrence probability in which an article of a different sorting hole is discharged. 
         [0004]    As illustrated in  FIG. 1 , in a parcel sorting system in the related art, while a cart  30  is moved by a track  20 , parcels  10   a  to  10   c  loaded on the cart  30  are classified to chutes  40  that match respective destinations, and positions that the article are dropped to the chutes become different depending on positions of the articles on the cart  30 . 
         [0005]    That is, in  FIG. 1 , the parcel  10   a  is dropped at a front side of the chute, the parcel  10   b  is dropped at a middle side of the chute, and the parcel  10   c  is dropped at a rear side of the chute, and the classification to the chutes may not be smoothly performed depending on the position of the parcel on the cart  30 . 
         [0006]    In order to solve the problem, a method of designing an inlet of the chute to have a size of 2 m or more is applied, but the size of the chute inlet is designed to be larger than necessary, and as a result, spatial efficiency may deteriorate. 
         [0007]    As described above, since it is difficult to accurately sort the parcel on the cart to the corresponding destination chute in the related art, a system for solving the problem is required. 
       SUMMARY OF THE INVENTION 
       [0008]    The present invention has been made in an effort to provide a system and a method for sorting a parcel that can accurately sort parcels by arranging the parcels on edges close to chutes for respective destinations on a cart. 
         [0009]    An exemplary embodiment of the present invention provides a system for sorting a parcel, which moves an article to a cart according to destination information of the article to classify the article to a chute for each destination, the system including: an article position detecting unit which detects positional information of the article loaded on the cart that moves in a first direction by a track which moves in the first direction; and a control unit which controls the cart to rotate in a second or third direction according to the detected positional information of the article and destination information of the article. 
         [0010]    The control unit may rotate the cart in the second direction so that the article is positioned at an edge of the cart in the second direction in the case where the article is positioned at the center of the cart or at an edge in the third direction, when the article needs to be classified to a first chute provided in the second direction of the cart according to the destination information of the article. 
         [0011]    The control unit may rotate the cart in the third direction so that the article is positioned at the edge of the cart in the third direction of the cart in the case where the article is positioned at the center of the cart or at the edge in the second direction, when the article needs to be classified to a second chute provided in the third direction of the cart according to the destination information of the article. 
         [0012]    The first direction may be vertical to the second direction or the third direction, and the second direction and the third direction may be completely opposite to each other. 
         [0013]    The article position detecting unit may include: a first sensor which linearly senses the article in the second or third direction of the cart; a second sensor which senses the article in a first diagonal direction of the cart; and a third sensor which is positioned to be opposite to the second sensor and senses the article in a second diagonal direction of the cart. 
         [0014]    The second sensor may be provided at the end of the track in the second direction of the cart, the third sensor may be provided at the end of the track in the third direction of the cart, and the first sensor may be provided at a position spaced apart from the third sensor by a predetermined distance. 
         [0015]    The control unit may calculate the position of the article by using a first sensing time which is a time interval between a time when the article is sensed by the second sensor and a time when the article is sensed by the first sensor, a speed of the track, a maximum value of the sensing times, and a long-axis length value of the cart, when the article needs to be classified to the first chute provided in the second direction of the cart according to the destination information of the article. 
         [0016]    The control unit may calculate the position of the article by using a second sensing time which is a time interval between a time when the article is sensed by the third sensor and the time when the article is sensed by the first sensor, the speed of the track, and a maximum value of the sensing times, and a length value of the cart, when the article needs to be classified to the second chute provided in the third direction of the cart according to the destination information of the article. 
         [0017]    The article position detecting unit may be a camera that photographs the cart and the article loaded on the cart. 
         [0018]    The control unit may calculate a position between the cart and the article from information on the image photographed by the camera by using an edge detection technique. 
         [0019]    The system may further include a transmitting unit which transmits a control signal for controlling rotation of the cart to the cart under the control by the control unit. Further, the system may further include a storing unit which stores the destination information of the article, the speed information of the track, and the positional information of the article. 
         [0020]    Another exemplary embodiment of the present invention provides a method for sorting a parcel, which loads an article on a cart according to destination information of the article to classify the article to a chute for each destination, including: calculating the position of the article loaded on the cart which moves in a first direction by a track; and moving the article on the cart to a second direction or a third direction that is an edge position which gets close to the chute for each destination on the cart, by moving a cross belt of the cart according to positional information of the article and destination information of the article. 
         [0021]    The calculating of the position of the article may include receiving image information for the article loaded on the cart; and calculating an interval between an edge of the cart and both sides of the article from the image information by using an edge extraction algorithm. 
         [0022]    The calculating of the position of the article may include sensing the article by using a first sensor that senses the article in a straight-line direction to a long-axis direction of the cart, a second sensor that is provided at the end of the third direction of the cart and senses the article in a diagonal direction of the cart, and a third sensor that is provided at the end of the second direction of the cart and senses the article in the diagonal direction of the cart; and sensing the position of the article by using a sensing time which is an interval between a time when the article is sensed by the diagonal sensor and a time when the article is sensed by the straight-line sensor. 
         [0023]    In the sensing of the position of the article, when the article needs to be classified to a first chute provided in the second direction of the cart according to the destination information of the article, it may be judged that the article is positioned at a position distant from the first chute on the cart in the case where the sensing time by the second sensor and the first sensor is long. 
         [0024]    In the sensing of the position of the article, when the article needs to be classified to a second chute provided in the third direction of the cart according to the destination information of the article, it may be judged that the article is positioned at a position distant from the second chute on the cart in the case where the sensing time by the third sensor and the first sensor is long. 
         [0025]    In the moving of the article on the cart to the second direction or the third direction that is the edge position which gets close to the chute for each destination, when the article needs to be classified to the first chute provided in the second direction of the cart according to the destination information of the article, in the case where the article is positioned at the center of the cart or at an edge in the third direction, the cross belt of the cart is moved in the second direction so that the article is positioned at the edge of the cart in the second direction. 
         [0026]    In the moving of the article on the cart to the second direction or the third direction that is the edge position which gets close to the chute for each destination, when the article needs to be classified to the second chute provided in the third direction of the cart according to the destination information of the article, in the case where the article is positioned at the center of the cart or at the edge in the second direction, the cross belt of the cart may be moved in the third direction so that the article is positioned at the edge of the cart in the third direction. 
         [0027]    The first direction may be vertical to the second or third direction. 
         [0028]    According to exemplary embodiments of the present invention, parcels are efficiently sorted in a parcel sorter to smoothly sort the parcels and missorting to a destination chute is decreased to improve performance of the parcel sorter. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0029]      FIG. 1  is an exemplary diagram of wrong parcel sorting in the related art. 
           [0030]      FIG. 2  is an overall configuration diagram of a system for sorting a parcel according to an exemplary embodiment of the present invention. 
           [0031]      FIG. 3  is a detailed configuration diagram of the system for sorting a parcel according to the exemplary embodiment of the present invention. 
           [0032]      FIG. 4  is an enlarged diagram of the system for sorting a parcel, which includes a sensor, according to the exemplary embodiment of the present invention. 
           [0033]      FIG. 5A  is an exemplary diagram illustrating a sensing method in a case in which the parcel is classified to a first chute in  FIG. 2 , and  FIG. 5B  is an exemplary diagram illustrating a sensing method in a case in which the parcel is classified to a second chute in  FIG. 2 . 
           [0034]      FIG. 6  is a diagram illustrating an example of sensing a position of an article by using a camera. 
           [0035]      FIG. 7  is a flowchart illustrating a method for sorting a parcel according to an exemplary embodiment of the present invention. 
           [0036]      FIG. 8  is a flowchart illustrating a method for sensing a position of an article by using a sensor according to an exemplary embodiment of the present invention. 
           [0037]      FIG. 9  is a flowchart illustrating a method for sensing a position of an article by using a camera according to an exemplary embodiment of the present invention. 
       
    
    
       [0038]    It should be understood that the appended drawings are not necessarily to scale, presenting a somewhat simplified representation of various features illustrative of the basic principles of the invention. The specific design features of the present invention as disclosed herein, including, for example, specific dimensions, orientations, locations, and shapes will be determined in part by the particular intended application and use environment. 
         [0039]    In the figures, reference numbers refer to the same or equivalent parts of the present invention throughout the several figures of the drawing. 
       DETAILED DESCRIPTION 
       [0040]    Hereinafter, for detailed description so as for those skilled in the art to easily carry out the technical spirit of the present invention, exemplary embodiments of the present invention will be described with reference to the accompanying drawings. 
         [0041]    The present invention relates to a technology that accurately and efficiently sorts a parcel loaded on a cart to a destination chute. 
         [0042]    Hereinafter, a system for sorting a parcel according to an exemplary embodiment of the present invention will be described with reference to  FIGS. 2 to 9 .  FIG. 2  is an overall configuration diagram of a system for sorting a parcel according to an exemplary embodiment of the present invention.  FIG. 3  is a detailed configuration diagram of the system for sorting a parcel. 
         [0043]    Referring to  FIGS. 2 and 3 , the system for sorting a parcel according to the present invention includes an inlet unit  100  in which the parcel is put, a track  200  which moves in a first direction, a cart  300  which is provided on the track  200 , chutes  400   a  and  400   b  provided in both directions of the track  200 , to which the parcel is sorted for each destination, an automatic parcel reading unit (OHS)  500 , an image acquiring unit  600 , a sensor unit  700 , a control unit  800 , and a transmitting unit  900 . 
         [0044]    When the inlet unit  100  is configured by a conveyor belt and a parcel  10  is loaded on the conveyor belt, the conveyor belt moves to load the parcel  10  on the cart  300  on the track  200 . 
         [0045]    The chutes  400   a  and  400   b  are divided into a first chute  400   a  and a second chute  400   b  for each destination, and parcels with the same destination are dropped for each chute. 
         [0046]    The automatic parcel reading unit  500  reads destination information of the parcel and transfers the read information to the control unit  800 . 
         [0047]    The image acquiring unit  600  as a camera photographs the parcel  10  on the cart  300 . 
         [0048]    The sensor unit  700  senses the position of an article to transfer a sensing result to the control unit  800 . 
         [0049]    The control unit  800  calculates the position of the parcel by using image information of the image acquiring unit  600  or sensor information of the sensor unit  700 . That is, the control unit  800  calculates an interval between both sides of the cart  300  and the parcel from the image information by using an edge detection technique, to calculate the position of the parcel. Further, the control unit  800  checks a sensing time from the sensor information to calculate the position of the parcel. A detailed method of calculating the position of the parcel will be described in detail with reference to  FIGS. 4 to 6  to be described below. Further, the control unit  800  receives the destination information from the parcel reading unit  500  to select the chutes  400   a  and  400   b  to which the parcel is to be discharged according to the destination information. That is, when the control unit  800  intends to discharge the parcel to the first chute  400   a,  the control unit  800  judges whether the parcel is positioned at an edge of the cart  300  in a second direction by using the image information or the sensor information, and when the parcel is spaced apart from the edge of the cart  300  in the second direction by a predetermined interval, the control unit  800  moves the parcel to the edge of the cart  300  in the second direction by controlling a cross belt of the cart  300 . Meanwhile, when the control unit  800  intends to discharge the parcel to the second chute  400   b,  the control unit  800  judges whether the parcel is positioned at an edge of the cart  300  in a third direction by using the image information or the sensor information, and when the parcel is spaced apart from the edge of the cart  300  in the third direction by a predetermined interval, the control unit  800  moves the parcel to the edge of the cart  300  in the third direction by controlling the cross belt of the cart  300 . 
         [0050]    The transmitting unit  900  transmits a control signal for controlling movement of the cross belt of the cart to the cross belt of the cart  300  under the control by the control unit  800 . 
         [0051]    A storing unit  1000  stores destination information of the article, speed information of the track, and positional information of the article. In this case, the destination information of the article may be acquired by recognizing characters attached to the parcel by the image acquiring unit  600  or the destination information recognized through a scanner or a server separately configured in the inlet unit  100 . 
         [0052]    Hereinafter, the system for sorting a parcel, which includes a sensor, according to the exemplary embodiment of the present invention will be described below with reference to  FIGS. 4 and 5 . 
         [0053]    As illustrated in  FIG. 4 , the track  200  moves in the first direction and the cross belt of the cart  300  rotates in the second or third direction. 
         [0054]    In this case, a long-axis length of the cart  300  has a length of “H”, and a third sensor  703  that senses the parcel in a diagonal direction is provided at the end of the track  200  in the second direction, a second sensor  702  that senses the parcel in the diagonal direction is provided at the end of the track  200  in the third direction, and a first sensor  701  that linearly senses the parcel in a longitudinal direction of the cart  300 is provided to be spaced apart from the second sensor  702 . In this case, the third sensor  703  performs diagonal sensing in a direction to face the first sensor  701  and the second sensor  702  performs diagonal sensing relative to a position opposite to the first sensor  701 . 
         [0055]    In  FIG. 2 , a method for sensing the position of the parcel when classifying the parcel to the first chute  400   a  provided in the second direction will be described with reference to  FIG. 5A . 
         [0056]    When the parcel needs to be classified to the first chute  400   a  of  FIG. 2 , a parcel  13  needs to be positioned at a second-direction edge  310  of the cart  300 . However, actually, when the parcel  13  is loaded on the cart  300 , the parcel  13  may not be often positioned at the edge  310 . Therefore, in the present invention, the position of the parcel  13  is sensed by using the first sensor  701  and the second sensor  702  as illustrated in  FIG. 5A . 
         [0057]    That is, the parcel  13  is first sensed at point a by the second sensor  702 , and while the parcel  13  moves by the track in the first direction, the parcel  13  is sensed at point b by the first sensor  701 . Therefore, a time from point a where the parcel is first sensed to point b is referred to as a first sensing time, and as the first sensing time is longer, a first side ef of the parcel  13  gets closer to a third-direction edge  320  of the cart  300 . On the contrary, as the first sensing time is shorter, the first side ef of the parcel  13  gets closer to the second-direction edge  310  of the cart  300 . In this case, since the parcel  13  needs to be classified to the first chute  400   a,  the parcel  13 , which is positioned to get closer to the second-direction edge  310  of the cart  300 , is easily classified to the first chute  400   a.  Accordingly, when the parcel  13  does not get closer to the second-direction edge  310  of the cart  310  according to the first sensing time sensed by the first sensor  701  and the second sensor  702 , that is, when the parcel  13  is positioned at the center of the cart  300  or positioned to get closer to the third-direction edge  320 , the parcel  13  is controlled to be positioned to get closer to the second-direction edge  310  of the cart  300  by rotating the cross belt of the cart  300  in the second direction. 
         [0058]    In this case, an equation for calculating the position of the first side ef of the parcel  13  is represented in Equation 1 below. 
         [0000]        x=H (m)· N (s)· U (m/s)/ Y (m)   [Equation 1]
 
         [0059]    Herein, x represents the position of the first side ef of the parcel  13 , H(m) represents a long-axis length of the cart  300 , N(s) represents the first sensing time from point a to point b, U(m/s) represents a speed of the track  200 , and Y(m) represents a distance between the first sensor  701  and the second sensor  702 . 
         [0060]    Meanwhile, in  FIG. 2 , the method for sensing the position of the parcel when classifying the parcel to the second chute  400   b  provided in the third direction will be described with reference to  FIG. 5B . 
         [0061]    When the parcel needs to be classified to the second chute  400   b  of  FIG. 2 , the parcel  13  needs to be positioned at the third-direction edge  320  of the cart  300 . However, actually, when the parcel  13  is loaded on the cart  300 , the parcel  13  may not be often positioned at the edge  320 . Therefore, the position of the parcel  13  is sensed by using the first sensor  701  and the third sensor  703  as illustrated in  FIG. 5B . 
         [0062]    That is, the parcel  13  is first sensed at point c by the third sensor  703 , and while the parcel  13  moves by the track in the first direction, the parcel  13  is sensed at point d by the first sensor  701 . Therefore, a time from point c where the parcel is first sensed to point d is referred to as a second sensing time, and as the second sensing time is longer, a second side gh of the parcel  13  gets close to the second-direction edge  310  of the cart  300 . On the contrary, as the second sensing time is shorter, the second side gh of the parcel  13  gets close to the third-direction edge of the cart  300 . In this case, since the parcel  13  needs to be classified to the second chute, the parcel  13 , which is positioned to get closer to the third-direction edge of the cart  300 , is easily classified to the second chute. Accordingly, when the parcel  13  does not get closer to the third-direction edge  320  of the cart  310  according to the sensing time sensed by the first sensor  701  and the third sensor  703 , that is, when the parcel  13  is positioned at the center of the cart  300  or positioned to get closer to the second-direction edge  310 , the parcel  13  is controlled to be positioned to get closer to the third-direction edge  320  of the cart  300  by rotating the cross belt of the cart  300  in the third direction. 
         [0063]    As such, the position of the second side gh of the parcel  13  may be calculated by adopting Equation 1 above. However, parameter x represents the position of the second side gh of the parcel  13 , H(m) represents the long-axis length of the cart  300 , N(s) represents the second sensing time from point c to point d, U(m/s) represents the speed of the track  200 , and Y(m) represents a distance between the first sensor  701  and the third sensor  703 . 
         [0064]      FIG. 6  is a diagram illustrating an example of sensing a position of an article by using a camera. 
         [0065]    The parcel  13  loaded on the cart  300  is photographed by using a camera that is the image acquiring unit  600 . Edges of the parcel  13  and the cart  300  are extracted from the information obtained from the photographed image through the edge extraction technique, and intervals E and F between the edges of the parcel  13  and the cart  300  are extracted. Therefore, the control unit  800  moves the cross belt of the cart  300  by using information on the intervals E and F between the edges of the parcel  13  and the cart  300 , and moves the parcel  13 . That is, when the parcel is intended to be classified to the first chute  400   a  in  FIG. 2 , the parcel  13  is moved in the second direction in  FIG. 6 , and when the parcel is intended to be classified to the second chute  400   b  of  FIG. 2 , the parcel  13  is moved in the third direction in  FIG. 6 . 
         [0066]    Hereinafter, a method for sorting a parcel according to an exemplary embodiment of the present invention will be described in detail with reference to  FIG. 7 . 
         [0067]    First, the control unit  800  receives the image information from the image acquiring unit  600  or receives the sensor information from the sensor unit  700  (S 101 ). 
         [0068]    Therefore, the control unit  800  calculates the position of the parcel on the cart by using the image information or the sensor information (S 102 ). 
         [0069]    Thereafter, the control unit  800  moves the parcel to an edge of the cart, which gets closer to a destination chute, by controlling movement of the cross belt of the cart according to the position of the parcel and destination information (S 103 ). In this case, the destination information may be received from a server of the inlet unit to be stored in advance, or acquired through the image acquiring unit  600 . 
         [0070]    Therefore, the parcel on the cart  300  is classified to a corresponding destination chute (S 104 ). 
         [0071]    Hereinafter, a method for sorting a parcel by using a sensor according to an exemplary embodiment of the present invention will be described in detail with reference to  FIG. 8 . 
         [0072]    First, the control unit  800  selects the chute according to the destination information (S 201 ). 
         [0073]    Therefore, when the first chute  400   a  is selected, the control unit  800  calculates a position of a first surface e, f of the parcel by using a first sensing time which is an interval between sensing points a and b of the first sensor  701  and the second sensor  702 , a long-axis direction length H of the cart  300 , a speed of the track  200 , and using a maximum value Y of the sensing times (S 202 ). 
         [0074]    Subsequently, the control unit  800  judges whether the parcel is spaced apart from a second-direction edge of the cart  300  by a predetermined distance or more by using the calculated positional information (S 203 ), and when the parcel is spaced apart by the predetermined distance or more, the control unit  800  moves the parcel to the second-direction edge  310  by moving the cross belt of the cart  300  in the second direction (S 204 ). 
         [0075]    Thereafter, the parcel is moved by the track  200  to be classified to the first chute  400   a  (S 205 ). 
         [0076]    Meanwhile, in process S 101 , when the second chute  400   b  is selected according to the destination information of the parcel, the control unit  800  calculates a position of a second surface g, h of the parcel by using a second sensing time which is an interval between sensing points a and c of the first sensor  701  and the third sensor  703 , the long-axis direction length H of the cart  300 , the speed of the track  200 , and a maximum value Y of the sensing times (S 206 ). 
         [0077]    Subsequently, the control unit  800  judges whether the parcel is spaced apart from a third-direction edge of the cart  300  by a predetermined distance or more by using the calculated positional information (S 207 ), and when the parcel is spaced apart by the predetermined distance or more, the control unit  800  moves the parcel to the third-direction edge  320  by moving the cross belt of the cart  300  in the third direction (S 208 ). 
         [0078]    Thereafter, the parcel is moved by the track  200  to be classified to the second chute  400   b  (S 209 ). 
         [0079]    Hereinafter, a method for sensing the position of an article by using a camera according to an exemplary embodiment of the present invention will be described in detail with reference to  FIG. 9 . 
         [0080]    First, the control unit  800  selects the chute according to the destination information (S 301 ). 
         [0081]    Therefore, when the first chute  400   a  is selected according to the destination information, the control unit  800  calculates the position of the parcel by using image information calculated from the camera (S 302 ). 
         [0082]    Thereafter, the control unit  800  judges whether the parcel is spaced apart from the second-direction edge of the cart  300  by a predetermined distance or more by using the calculated positional information (S 303 ), and when the parcel is spaced apart by the predetermined distance or more, the control unit  800  moves the parcel to the second-direction edge  310  by moving the cross belt of the cart  300  in the second direction (S 304 ). 
         [0083]    Thereafter, the parcel is moved by the track  200  to be classified to the first chute  400   a  (S 305 ). 
         [0084]    Meanwhile, in process S 301 , when the second chute  400   b  is selected according to the destination information of the parcel, the control unit  800  calculates the position of the parcel by using the image information received from the camera (S 306 ). 
         [0085]    Subsequently, the control unit  800  judges whether the parcel is spaced apart from a third-direction edge of the cart  300  by a predetermined distance or more by using the calculated positional information (S 307 ), and when the parcel is spaced apart by the predetermined distance or more, the control unit  800  moves the parcel to the third-direction edge  320  by moving the cross belt of the cart  300  in the third direction (S 308 ). 
         [0086]    Thereafter, the parcel is moved by the track  200  to be classified to the second chute  400   b  (S 309 ). 
         [0087]    As described above, the present invention relates to the system for sorting a parcel, which automatically sorts the parcel, and the articles loaded on the cart is, are advance, positioned on the cart for each destination direction by using the image information and the sensor information, thereby reducing a missorting probability and the width of a sorting hole to increase spatial efficiency. 
         [0088]    The exemplary embodiments of the present invention are illustrative only, and various modifications, changes, substitutions, and additions may be made without departing from the technical spirit and range of the appended claims by those skilled in the art, and it will be appreciated that the modifications and changes are included in the appended claims.