Abstract:
A method for graphically guiding visitors of a building to a shortest path using an integrated reader and access control is provided. The method includes receiving a user&#39;s identification code, receiving a user&#39;s destination location, uploading a current floor plan of a location, determining non-accessible areas in the location based on the user&#39;s identification code, and computing a shortest path from a present location to the destination location, wherein the shortest path circumvents the non-accessible areas.

Description:
FIELD OF INVENTION 
       [0001]    The present invention relates generally to visitor management systems and access control. More particularly, the present invention relates to systems and methods for graphically guiding visitors of a building to a shortest path using an integrated reader and access control. 
       BACKGROUND 
       [0002]    In many large buildings and facilities, for example, airports and corporate or manufacturing facilities, security is important. Thus, when a guest visits the building, he is often escorted to his host, and his host is responsible for guiding the guest throughout the building during the guest&#39;s stay. However, when many guests frequently visit a particular building, escorting guests to their hosts can be tedious and time consuming. 
         [0003]    To alleviate this burden, many large buildings employ visitor management systems to handle guests&#39; check in and check out process. The guest management system can be integrated with a physical access control system, and the access control system can provide a guest with a temporary access card or badge. A temporary access card can provide limited access levels to the guest for the period of the guest&#39;s visit. For example, a guest can swipe his temporary access card at access points or readers in the building to traverse the building and reach his host and/or destination. 
         [0004]    Because guests are often unfamiliar with a large building or enterprise, it is common for guests to get lost. When lost, a guest must consult a static floor plan or map in the building and/or ask for assistance from others. This approach can be tiresome and time consuming for a guest because a static floor plan does not indicate the guest&#39;s position in the building. Furthermore, a static floor plan does not factor in the guest&#39;s access levels when displaying possible paths from one position to another. 
         [0005]    There is thus a continuing, ongoing need for systems and methods for graphically guiding visitors of a building to a shortest path using an integrated reader and access control. Preferably such systems and methods are easily usable, visually appealing, and dynamically configurable while taking into account building security. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0006]      FIG. 1  is a flow diagram of a method of determining a shortest path in accordance with the present invention; 
           [0007]      FIG. 2  is a block diagram of a system for carrying out the method of  FIG. 1  in accordance with the present invention; 
           [0008]      FIG. 3  is a bitmap image of a floor plan in accordance with the present invention; 
           [0009]      FIG. 4  is a pixel block image of the bitmap image of  FIG. 3  in accordance with the present invention; 
           [0010]      FIG. 5  is a pixel matrix of the pixel block image of  FIG. 4  in accordance with the present invention; 
           [0011]      FIG. 6  is a compacted matrix of the pixel matrix of  FIG. 5  in accordance with the present invention; 
           [0012]      FIG. 7A  is a first computed path using the compacted matrix of  FIG. 6  in accordance with the present invention; and 
           [0013]      FIG. 7B  is a second computed path using the compacted matrix of  FIG. 6  in accordance with the present invention. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0014]    While this invention is susceptible of an embodiment in many different forms, there are shown in the drawings and will be described herein in detail specific embodiments thereof with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention. It is not intended to limit the invention to the specific illustrated embodiments. 
         [0015]    Embodiments of the present invention include systems and methods for graphically guiding visitors of a building to a shortest path using an integrated reader and access control. Preferably such systems and methods are easily usable, visually appealing, and dynamically configurable taking into account building security. 
         [0016]    In accordance with the present invention, an improved access control device can be placed at each access point in an access control system employed in a building. When a guest swipes his access card, the improved access control device can dynamically compute and graphically display a shortest path from the access control device to the guest&#39;s destination. The destination could be another access control device or a location of a host in the building. 
         [0017]    For example, when a guest arrives at a building, he can be provided with a temporary access card. The temporary access card can be programmed with the guest&#39;s unique host destination code or address. In some embodiments, the host destination code can be a value configured by an operator of the access control system that is integrated with a visitor management system. 
         [0018]    An access control device can be placed at each access point in the building. In embodiments of the present invention, each access control device can contain the latest floor plan for the building. The floor plan can be uploaded through associated access system host software. For example, the latest floor plan can be uploaded from an associated control unit. 
         [0019]    When an access card is presented to an access control device, the device can extract the unique card number and the host destination code programmed into the card. The access control device can then validate the card and use the host destination code to compute a shortest path to the host destination. In embodiments of the present invention, the access control device can factor in access levels available to the guest when computing the shortest path. 
         [0020]    In accordance with the present invention, a shortest path can be computed using a floor plan of a building and an access level of a guest. For example, after obtaining the access level of a guest, systems and methods of the present invention can alter the floor plan of the building to create a temporary floor plan. The temporary floor plan can include obstacles that correlate to access points for which the guest does not have access. 
         [0021]    Systems and methods of the present invention can convert the temporary floor plan into a pixel matrix of 0&#39;s and 1&#39;s. In embodiments, a 1 can correspond to a path available to the guest, and a 0 can correspond to an obstacle, that is, a path that is not available to the guest. The pixel matrix can then be compacted into a matrix with smaller dimensions. For example, a block of pixels in the pixel matrix with the same value can be mapped into a single pixel in the compacted matrix with that value. 
         [0022]    Using the compacted matrix, systems and methods in accordance with the present invention can compute a shortest path between two blocks of pixels. For example, all possible paths between two blocks of pixels can be computed by propagating through the four axial neighbors of each pixel from the source location to the destination location. If a given pixel location in the compacted matrix can be represented by (5,5), then that location&#39;s four axial neighbors are (4,5), (5,6), (6,5), and (5,4). 
         [0023]    When all of the possible paths are computed, the shortest path can be selected. In embodiments, if two or more possible paths have the same distance, then the path with the lowest number of turns can be considered the shortest path. 
         [0024]    In embodiments of the present invention, when the shortest path is computed and determined, an access control device can graphically display the route map. In some embodiments, the access control device can also print the route map showing the shortest path. 
         [0025]      FIG. 1  is a flow diagram of a method  100  of determining a shortest path in accordance with the present invention. As seen in  FIG. 1 , a temporary floor plan can be created as in  110 . The temporary floor plan can include obstacles that correspond to areas in the floor plan that are not accessible to a user. 
         [0026]    The temporary floor plan can be converted to a pixel matrix as in  120 . The pixel matrix can represent an obstacle with a 0 and a possible path with a 1. Then, the pixel matrix can be compacted as in  130 . For example, blocks of pixels in the pixel matrix that have the same value can be grouped together in the compacted matrix. 
         [0027]    The shortest path from a source pixel in the compacted matrix to a destination pixel in the compacted matrix can be estimated as in  140 . For example, possible paths between two blocks of pixels can be computed by propagating through the four axial neighbors of each pixel from the source location to the destination location. Then, a route map showing the shortest path can be displayed to a user as in  150 . 
         [0028]    The method of  FIG. 1  and others in accordance with the present invention can be implemented with the system  200  shown in  FIG. 2 . As seen in  FIG. 2 , a plurality of control access devices  210   a,    210   b,  . . .  210   n  in a building can be in wired or wireless communication with a control unit  220 . The control unit  220  can be implemented with one or more programmable processors  220 - 1  and executable control software  220 - 2  as would be understood by those of ordinary skill in the art. The executable control software  220 - 2  can be stored on a transitory or non-transitory local computer readable medium. 
         [0029]    Each of the plurality of control access devices  210   a,    210   b,  . . .  210   n  can include one or more programmable processors  210 - 1  and executable control software  210 - 2 . Each device  210   a,    210   b,  . . .  210   n  can also include an output display  212  and one or more input devices  214 . The output display  212  can include a multi-dimensional graphical user interface. The input devices  214  can include a keypad and/or a scanner for reading an access card. 
         [0030]    In embodiments of the present invention, when an access card is presented to the input device  214  of a control access device  210 , the display  214  of the device  210  can present a graphical display of a shortest path to the user. In some embodiments, the device  210  can be interactive. 
         [0031]    As explained above, to compute a shortest path, systems and methods of the present invention can create a temporary floor plan, a pixel matrix, and a compacted matrix. A temporary floor plan can be a bitmap image of a floor plan of a building, for example, the bitmap image  300  of  FIG. 3 . As seen in  FIG. 3 , if the bitmap image  300  is black and white, then obstacles for non-accessible areas can be displayed as dark blocks  310 . When the bitmap image is in color, white can represent possible paths, and all colors can represent obstacles. 
         [0032]    The bitmap image  300  of  FIG. 3  can be converted into a pixel block image. For example,  FIG. 4  is a pixel block image  400  of the bitmap image  300  of  FIG. 3 . As can be seen in  FIG. 4 , the pixel block image  400  splits the bitmap image  300  into pixel blocks. Each pixel block can represent information of a small area on the floor plan. 
         [0033]    The pixel block image  400  of  FIG. 4  can be converted into a pixel matrix. For example,  FIG. 5  is a pixel matrix  500  of the pixel block image  400  of  FIG. 4 . As can be seen in  FIG. 5 , the pixel matrix  500  can be a series of 1&#39;s and 0&#39;s. A 1 can represent a possible path, and a 0 can represent an obstacle. 
         [0034]    The pixel matrix  500  of  FIG. 5  can be converted into a compacted matrix. For example,  FIG. 6  is a compacted matrix  600  of the pixel matrix  500  of  FIG. 5 . In some embodiments, the compacted matrix  600  can be created by grouping blocks of pixels in the pixel matrix  500  that have the same value. In other embodiments, the compacted matrix  600  can be created by grouping X number of pixels in pixel matrix  500 , regardless of pixel value. 
         [0035]    For example, the compacted matrix  600  can be created by grouping every two pixels in the pixel matrix  500 . When a small number of pixels, such as two, are grouped, the accuracy of computed paths will not be affected. 
         [0036]    When the pixel matrix  500  has dimensions M×N and when every X number of pixels in the pixel matrix  500  are grouped, the dimensions of the compacted matrix will be (M/X)×(N/X). In embodiments of the present invention, if any pixel in a block to be grouped together is an obstacle, the corresponding pixel in the compacted matrix  600  will be set to 0. 
         [0037]      FIG. 6  is a compacted matrix  600  of the pixel matrix  500  when every two pixels have been grouped together. Thus, the pixel matrix  500  is 10×10, and the pixel matrix  600  is (10/2)×(10/2), or 5×5. 
         [0038]    Embodiments of the present invention do not compute diagonal traversing paths. Rather, embodiments of the present invention compute straight, that is, axial, paths. Therefore, when computing possible, paths, systems and methods of the present invention consider the four axial neighbors of each location. 
         [0039]    When computing possible paths, a position index of a pixel location can be stored in a one-dimensional array, A. If there is a possible path in any of the pixel&#39;s four axial neighbors, the possible path can be appended to the one-dimensional array, A. Possible paths in a pixel location&#39;s four axial neighbors can be computed and appended to the one-dimensional array, A, until a destination location is reached. In this manner, the completed one-dimensional array, A, can provide possible paths from a source location to the destination location. 
         [0040]    For example, a source position of the compacted matrix  600  can be stored in the one-dimensional array, A, as an element, E, where E=(m/2)×(1+n/2). Thus, where a source position (x,y) is (1,2) in the matrix  600 , the corresponding element, E in the one-dimensional array, A, can be E=(1/2)×(1+2/2)=½×2=1. 
         [0041]    Similarly, an index position can be determined from the one-dimensional array, A, where the index position is (E/m, E % m). Thus, where E=1, the index position is (1/m, 1% m). 
         [0042]    In accordance with the present invention, the first possible path can be stored in the one-dimensional array, A. Other alternate paths can be computed using a temporary one-dimensional array, B. If the length of the path in B is smaller than the length of the path in A, then the path in A can be replaced with the path in B. This can be repeated for all possible paths so that, when completed, the one-dimensional array, A, will contain the shortest path. In embodiments of the present invention, when two paths have the same length, the path with the lowest number of turns can be considered the shortest path. 
         [0043]      FIG. 7A  is a first computed path  700  using the compacted matrix of  FIG. 6 , and  FIG. 7B  is a second computed path  700 ′ using the compacted matrix of  FIG. 6 . For exemplary purposes, position (0,0) can be considered the source location, and position (4,4) can be considered the destination location. 
         [0044]    Location (0,0) has two axial neighbors: (1,0) and (0,1).  FIG. 7A  shows the path  700  through (1,0), and  FIG. 7B  shows the path  700 ′ through (0,1). The path  700  through (1,0) shown in  FIG. 7A  is longer than the path  700 ′ through (0,1) shown in  FIG. 7B . Therefore, the path  700 ′ through (0,1) in  FIG. 7B  can be considered the shortest path. As seen in  FIG. 7B , the shortest path  700 ′ traverses through the following locations: (0,0), (0,1), (0,2), (0,3), (0,4), (1,4), (2,4), (3,4), and (4,4). 
         [0045]    Although a few embodiments have been described in detail above, other modifications are possible. For example, the logic flows depicted in the figures do not require the particular order shown, or sequential order, to achieve desirable results. Other steps may be provided, or steps may be eliminated, from the described flows, and other components may be added to, or removed from, the described systems. Other embodiments may be within the scope of the following claims. 
         [0046]    From the foregoing, it will be observed that numerous variations and modifications may be effected without departing from the spirit and scope of the invention. It is to be understood that no limitation with respect to the specific system or method illustrated herein is intended or should be inferred. It is, of course, intended to cover by the appended claims all such modifications as fall within the spirit and scope of the claims.