Patent Publication Number: US-2005137827-A1

Title: System and method for managing arrangement position and shape of device

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
      This application is based upon and claims the benefit of priority from prior Japanese Patent Application No. 2003-425036, filed Dec. 22, 2003, the entire contents of which are incorporated herein by reference.  
     BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      The present invention relates to a device management system for managing the arrangement positions and shapes of devices that are present in facilities such as an office or a factory.  
      2. Description of the Related Art  
      In general, various electronic devices, such as personal computers, server computers, printers and facsimiles, are used in facilities such as offices and factories. In houses, too, various electronic devices, such as personal computers, TVs, video recorders, refrigerators and microwave ovens, are used.  
      Jpn. Pat. Appln. KOKAI Publication No. 2003-177980 discloses an information providing system that provides a mobile terminal with information (kinds of devices, services associated with devices) relating to devices that are present in a room. In this information providing system, a directory server is used. The directory server prestores information relating to each of devices that are present in respective rooms. Based on position information that is sent from the mobile terminal, the directory server provides the mobile terminal with information relating to each of devices that are present in a room where the mobile terminal is currently present.  
      In facilities such as offices and factories, however, the locations where the electronic devices are arranged vary greatly with time because of, for instance, a change in layout of in rooms, or a change of personnel. Thus, it is a difficult work for a facility manager to exactly understand where the individual electronic devices are actually present.  
      In particular, in a warehouse where many electronic devices are stored, a great deal of time and labor is required in order to search for an electronic device, since the locations of individual electronic devices in the warehouse and the shapes of the electronic devices are not understandable.  
      Under the circumstances, there is a need to realize a function for managing the actual locations of individual electronic devices.  
     BRIEF SUMMARY OF THE INVENTION  
      According to an aspect of the present invention, there is provided a system comprising: a first sensor, a second sensor and a third sensor, each of the sensors being configured to detect a distance from each of electronic devices that are present in a space and an identifier of each of the electronic devices by using a wireless signal; and a host apparatus that executes communication with each of the first sensor, second sensor and third sensor, the host apparatus including: a detection unit configured to detect a position of each of the electronic devices in the space, based on the distance from each of the electronic devices, which is detected by the first sensor, second sensor and third sensor, and a position of each of the first sensor, second sensor and third sensor in the space; and an information acquisition unit configured to acquire shape information representative of a shape of each of the electronic devices from each of the electronic devices, by executing wireless communication with each of the electronic devices using the identifier of each of the electronic devices, which is detected by the first sensor, second sensor and third sensor. 
    
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING  
      The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention, and together with the general description given above and the detailed description of the embodiments given below, serve to explain the principles of the invention.  
       FIG. 1  is a block diagram showing the configuration of a device management system according to an embodiment of the present invention;  
       FIG. 2  is a block diagram showing the structure of an electronic device that is used in the device management system according to the embodiment;  
       FIG. 3  is a diagram for explaining how the position of each electronic device is detected in the device management system according to the embodiment;  
       FIG. 4  is a flow chart illustrating the operation of each sensor provided in the device management system according to the embodiment;  
       FIG. 5  is a flow chart illustrating the operation of a host apparatus provided in the device management system according to the embodiment;  
       FIG. 6  is a flow chart illustrating an example of a layout-view automatic production process procedure that is executed by the device management system according to the embodiment;  
       FIG. 7  shows an example of a layout screen that is produced by the device management system according to the embodiment;  
       FIG. 8  illustrates a state in which a master acquires self-data of a slave in the device management system according to the embodiment; and  
       FIG. 9  is a flow chart illustrating the operation of the master shown in  FIG. 8 . 
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
      An embodiment of the present invention will now be described with reference to the accompanying drawings.  
       FIG. 1  shows the configuration of a device management system according to an embodiment of the invention. This device management system is a system for recognizing the arrangement positions of individual electronic devices, which are present in a space to be managed, and the shapes of the individual electronic devices. The to-be-managed space is, for instance, a room or a warehouse that is present in facilities such as an office or a factory. The device management system includes a host apparatus  11  and three (first to third) sensors  21 ,  22  and  23 .  
      The three sensors  21 ,  22  and  23  are a sensor group for detecting the arrangement positions of the individual electronic devices in the three-dimensional (3D) to-be-managed space. The sensors  21 ,  22  and  23  are discretely arranged at predetermined positions within the 3D to-be-managed space. For example, the first sensor  21  is disposed at a predetermined position on the X coordinate axis of an XYZ coordinate system defined in the 3D to-be-managed space. The second sensor  22  is disposed at a predetermined position on the Y coordinate axis, and the third sensor  23  is disposed at a predetermined position on the Z coordinate axis. Each of the sensors  21 ,  22  and  23  detects a distance between the position thereof and the respective electronic devices that are present in the 3D to-be-managed space by using a wireless signal such as an acoustic wave or an electromagnetic wave (“distance measurement”).  
      In the 3D to-be-managed space, a plurality of devices  31  are arranged. Each device  31  is an electronic device such as a personal computer, a server computer, a printer, a facsimile, a TV, or a video recorder. Each device  31  stores self-data that is indicative of its own attributes. The self-data includes a device identifier (device ID) and shape data that is indicative of the shape of the device. Further, each device  31  includes a wireless communication unit.  
      The sensor  21  broadcast-transmits, e.g. a beacon signal within the to-be-managed space and uses a response signal (ACK) to the beacon signal, thereby detecting the device ID of each device  31 , and a distance between each device  31  and the sensor  21 . Specifically, the sensor  21  measures an elapsed time (response time) from when the beacon signal is transmitted to when the response signal (ACK) is received. The sensor  21  detects the measured response time as the distance. The beacon signal is a polling signal for searching for the devices. The response signal (ACK) from each device  31  includes the device ID thereof. If each device sends a response signal (ACK) including a time stamp that indicates a transmission time of the response signal (ACK), the sensor  21  can detect, as the distance, the difference between the time point indicated by the time stamp and the time point when the response signal (ACK) is received.  
      Each of the sensors  22  and  23  has the same structure as the sensor  21 . Specifically, the sensor  22  broadcast-transmits a beacon signal within the to-be-managed space and uses a response signal (ACK) to the beacon signal, thereby detecting the device ID of each device  31  and a distance between each device  31  and the sensor  22 . In this case, the sensor  22  measures a time (response time) from a time when the beacon signal is transmitted to a time when the response signal (ACK) is received, and detects the measured response time as the distance. Similarly, the sensor  23  broadcast-transmits a beacon signal within the to-be-managed space and uses a response signal (ACK) to the beacon signal, thereby detecting the device ID of each device  31  and a distance between each device  31  and the sensor  23 . In this case, the sensor  23  measures an elapsed time (response time) from when the beacon signal is transmitted to when the response signal (ACK) is received, and detects the measured response time as the distance.  
      If each device  31  sends a response signal (ACK) including a time stamp that indicates a transmission time of the response signal (ACK), each of the sensors  22  and  23 , like the sensor  21 , can detect, as the distance, the difference between the time point indicated by the time stamp and the time point when the response signal (ACK) is received.  
      The sensors  21 ,  22  and  23  transmit beacon signals in a predetermined order. For example, the sensor  21  first transmits the beacon signal. After a predetermined time period, the sensor  22  transmits the beacon signal. Further, after a predetermined time period, the sensor  23  transmits the beacon signal.  
      The host apparatus  11  is connected to the sensors  21 ,  22  and  23  via, e.g. a wired or wireless network  1 . The host apparatus  11  executes communications with the sensors  21 ,  22  and  23  via the network  1 , thereby to control the operations of the sensors  21 ,  22  and  23 . In addition, using the device IDs detected by the sensors  21 ,  22  and  23 , the host apparatus  11  executes wireless communication with each of the devices  31  that are present in the 3D to-be-managed space.  
      The host apparatus  11  includes a position detection unit  111  and a shape data acquisition unit  112 . The position detection unit  111  detects a position in the to-be-managed space, where each device  31  is disposed, on the basis of the distance from each device  31 , which is detected by the sensor  21 ,  22 ,  23 , and the positions of the sensor  21 ,  22 ,  23  in the 3D to-be-managed space. The shape data acquisition unit  112  executes wireless communication with each device  31 , and acquires shape data from each device  31 . The wireless communication between the shape data acquisition unit  112  and each device  31  is executed using the device ID that is detected by the sensor  21 ,  22 ,  23 . If the sensors  21 ,  22  and  23  detect two devices ID #1 and ID #2, the shape data acquisition unit  112  transmits a shape data acquisition request (REQ) including the device ID #1 as a destination address, and acquires shape data from the device  31  that is designated by the device ID #1. Further, the shape data acquisition unit  112  transmits a shape data acquisition request (REQ) including the device ID #2 as a destination address, and acquires shape data from the device  31  that is designated by the device ID #2.  
      The host apparatus  11  is connected to a client terminal  51  via a wired or wireless network  2 . The client terminal  51  is realized by, e.g. a personal computer. In the client terminal  51 , a design support program, such as CAD (computer-aided design) software, is preinstalled. The design support program has a function of automatically producing a layout view that shows the arrangement position and the shape of each device  31  in the to-be-managed space, on the basis of the position of each device detected by the host apparatus  11  and the shape data of each device acquired by the host apparatus  11 . This layout-view automatic production function may be provided in the host apparatus  11 .  
       FIG. 2  shows the structure of each device  31 .  
      Each device  31  has housing and an ID transmission module  311  in order to realize cooperation with the device management system of the present embodiment. The ID transmission module  311  is a module that is attachable/detachable to/from the housing of the associated device  31 . For example, the ID transmission module  311  is realized as a card. The card that constitutes the ID transmission module  311  includes a memory  312  and a wireless communication unit  313 .  
      The memory  312  comprises, e.g. a nonvolatile memory, which stores self-data. The self-data includes, in addition to the device ID of the associated device  31 , size data (W×H×D) indicative of the size and shape of the housing of the device  31 , color data (RGB) indicative of the color, and image data of the housing of the device  31 . The size data (W×H×D), color data (RGB) and image data are used as shape data of the device  31 . The image data is, for instance, image data representative of the texture of the surface of the housing of the device  31 , or a photo image that is obtained by imaging the device  31 . Additionally, information indicative of the weight of the device  31  may be stored in the memory  312  as information that is included in the self-data.  
      The wireless communication unit  313  executes wireless communication with the outside. If the wireless communication scheme for communication between the device  31  and each sensor  21 ,  22 ,  23  is different from the wireless communication scheme for communication between the device  31  and the host apparatus  11 , the ID transmission module  311  is equipped with two kinds of wireless communication units  313 .  
      Referring now to  FIG. 3 , how to detect the position of the device  31  is described.  
      As is shown in  FIG. 3 , the sensors  21 ,  22  and  23  are disposed on known positions on the X, Y and Z axes of the 3D coordinate system that is defined in a room. For example, the position of the sensor  21  is (x, 0, 0), the position of the sensor  22  is (0, y, 0), and the position of the sensor  23  is (0, 0, z).  
      The sensor  21  detects a time (response time Tx) from a time when the sensor  21  transmits a beacon signal to a time when the sensor  21  receives a response signal (ACK) from the device  31 , and detects the response time Tx as the distance between the sensor  21  and the device  31 . Conversion from the response time Tx to a physical distance value is executed by, e.g. the position detection unit  111 . The position detection unit  111  converts the response time Tx to a value indicative of the physical distance between the sensor  21  and device  31 , on the basis of the value of the propagation speed of a wireless signal that is used for the wireless communication between the sensor  21 ,  22 ,  23  and each device  31 . For example, the physical distance is given by multiplying the value of ½ of the response time Tx by the value of the propagation speed of the wireless signal.  
      The sensor  22  measures an elapsed (response time Ty) from when the sensor  22  transmits the beacon signal to when the sensor  22  receives the response signal (ACK), and detects the measured response time Ty as the distance between the sensor  22  and the device  31 . Conversion from the response time Ty to a physical distance value is executed on the basis of the value of the propagation speed of a wireless signal that is used for the wireless communication between the sensor  21 ,  22 ,  23  and each device  31 .  
      The sensor  23  measures an elapsed (response time Tz) from when the sensor  23  transmits the beacon signal to when the sensor  23  receives the response signal (ACK), and detects the measured response time Tz as the distance between the sensor  23  and the device  31 . Conversion from the response time Tz to a physical distance value is executed on the basis of the value of the propagation speed of a wireless signal that is used for the wireless communication between the sensor  21 ,  22 ,  23  and each device  31 .  
      The sensors  21 ,  22  and  23  are disposed at the known positions. Thus, the position (x, y, z) of each device  31  in the 3D space can be specified by detecting the distance s between the sensor  21 ,  22 ,  23  and each device  31 .  
      Next, referring to a flow chart of  FIG. 4 , the operation that is executed by each sensor  21 ,  22 ,  23  is described.  
      The each of sensors  21 ,  22 ,  23  broadcast-transmits a beacon signal for searching for the device  31  in the to-be-managed space (step S 101 ). The device  31 , which receives the beacon signal, sends a response signal (ACK) with the device ID to the sensor from which the beacon signal is transmitted. Upon receiving the response signal (ACK) (step S 102 ), each sensor  21 ,  22 ,  23  calculates the response time from a time when the beacon is transmitted to a time when the response signal (ACK) is received, as the distance between the sensor and the device  31  that transmits the response signal (ACK) (step S 103 ).  
      Subsequently, the each of sensors  21 ,  22 ,  23  sends the response time and the device ID included in the received response signal (ACK) to the host apparatus  11  (step S 104 ). Thereby, with respect to each ID, three response times associated with the sensors  21 ,  22  and  23  are delivered to the host apparatus  11 .  
      Next, referring to a flow chart of  FIG. 5 , the operation that is executed by the host apparatus  11  is described.  
      If the host apparatus  11  receives the three response times from the sensors  21 ,  22  and  23  in association with the same device ID, the host apparatus  11  executes a process for specifying the position of the device associated with this device ID (step S 201 ). In step S 201 , the host apparatus  11  converts the response time Tx detected by the sensor  21 , the response time Ty detected by the sensor  22  and the response time Tz detected by the sensor  23  to physical distance values. Based on the three distance values obtained by the conversion and the arrangement positions of the sensors  21 ,  22  and  23 , the host apparatus  11  computes the position (x, y, z) of the device.  
      Thereafter, the host apparatus  11  transmits a shape information acquisition request to the device that is designated by each of the device IDs received from the sensors  21 ,  22  and  23 . Thus, the host apparatus  11  receives self-data including shape information from each device designated by the associated device ID (step S 202 ).  
      Referring to a flow chart of  FIG. 6 , a description is given of the layout-view automatic production process that is executed by the client terminal  51 .  
      Upon receiving the position information and shape information of each device  31  from the host apparatus  11 , the client terminal  51  executes the following process.  
      The client terminal  51  generates an image of walls of a room on a 3D layout screen, on the basis of the positions of the sensors  21 ,  22  and  23  in the 3D space (step S 301 ). The 3D layout screen is a 3D drawing screen that is provided by the CAD software. In step S 301 , an image  100  of the 3D walls is drawn, as shown in  FIG. 7 .  
      Next, the client terminal  51  determines the position of each device  31  on the 3D layout screen, on the basis of the position information of each device  31  (step S 302 ). Then, based on the shape information of each device  31 , the client terminal  51  generates 3D objects  101  that represent the shapes of the respective devices, and arranges the 3D objects  101  at associated positions on the 3D layout screen, as shown in  FIG. 7  (step S 303 ). The surfaces of the 3D object  101  are painted with colors that are designated by the shape information.  
      By viewing the 3D layout screen, the facility manager can easily understand where the respective devices are located, and what shapes they have.  
      Referring now to  FIG. 8 , a description is given of a process for acquiring self-data of mutually associated devices at a time, from a certain one of the mutually associated devices.  
      In general, many devices are mutually associated in operation. One of mutually associated devices (e.g. a personal computer and a printer connected to the personal computer; or a TV and a video recorder connected to the TV) functions as a master, and the other as a slave. In  FIG. 8 , a device (A)  31  and a device (B)  31  are connected by a cable  100  such as a USB cable. The device (A)  31  functions as a master, and the device (B)  31  as a slave. The device (A)  31  and device (B)  31  are disposed close to each other.  
      The device (A)  31  acquires self-data stored in the device (B)  31  from the device (B)  31  over the cable  100 . The device (A)  31  adds the acquired self-data to its own self-data as slave information indicative of a peripheral device of the device (A)  31 . The device (B)  31  does not respond to the beacon signal, and only the device (A)  31  responds to the beacon signal. The device ID and position of the device (A)  31  alone are detected, and the device ID and position of the device (B)  31  are not detected.  
      The operation that is executed by the device (A)  31  is described with reference to a flow chart of  FIG. 9 .  
      As described above, the device (A)  31  acquires self-data stored in the device (B)  31  from the device (B)  31  over the cable  100 , and adds the acquired self-data to its own self-data as slave information indicative of a peripheral device of the device (A)  31  (step S 401 ). Upon receiving the shape data acquisition request (REQ) including the device ID of the device (A)  31  from the host apparatus  11 , the device (A)  31  transmits both of its own self-data and the slave information to the host apparatus  11  (step S 403 ). Only by executing communication with the device (A)  31 , the host apparatus  11  can recognize not only the shape of the device (A)  31 , but also the presence of a peripheral device near the device (A)  31  and the shape of the peripheral device. Thereby, the host apparatus  11  can recognize the positions and shapes of the individual devices in the to-be-managed space with a less number of times of communication.  
      As has been described above, according to the device management system of the present embodiment, it becomes possible to exactly recognize the arrangement positions and shapes of electronic devices in a space such as a room or a warehouse. This system can efficiently support works such as inventory management in a warehouse, preparation for a move, a change of layout in a room, etc.  
      Additional advantages and modifications will readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details and representative embodiments shown and described herein. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.