Abstract:
A drawing management device for managing the drawing of an entire facility, such as a water supply facility, as digital information. This device includes a unit for storing drawings with priorities obtained by separating the entire facility drawing into sub-facility drawings located at plural levels, a selective display designating unit for displaying a desired sub-facility drawing obtained by selecting the number of levels considering the priority from the storing unit, and a display unit for displaying the desired sub-facility drawing in response to the signal from the selective display designating unit. By suitably selecting a desired level considering the priority, only a necessary and sufficient facility drawing can be displayed swiftly.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to a drawing management device for managing the drawings of facilities, such as a pipe laying system of a water and gas supply, a wiring system for electric power and telephone, a road for vehicles, etc., in the form of digitized information. It should be noted that the term ‘drawing’ as used herein refers to a drawing of the facility, such as a water supply, a machine design drawing, a road traffic map, etc. 
     Traditionally, the state of facilities, such as a pipe system for water and gas supply, and a wiring arrangement for electric power and telephone communication, has been provided in the form of a drawing drafted on a sheet of paper or polyester film. In this case, each change in the facilities requires a modification to be made to the drawing. The work of modifying the drawing must be performed manually with the result that a long time and much labor are required and also the possibility that errors will be made in modifying the drawing is relatively strong. In order to solve such a problem, it has been proposed to manage the facility drawing in the form of its digitized information. More specifically, as disclosed in JP-A-63-254565, the management is performed by displaying the many facility drawings (e.g., topography drawings, system drawings and symbol drawings) stored is digital data in a file device on a display device under computer control. The work for modifying the drawings is also made under computer control for the drawings displayed on the display device. 
     However, the above prior art has the following defects. In displaying large scale drawing data including e.g. qualifying lines, the processing therefor is executed at a very low speed since the data amount to be drawn or displayed during a unit time is very large. This is because even if only a part of the drawing is required, all the data including minute and detailed character information, which is difficult to recognize, are displayed. Therefore, the above prior art system is poor in its usability and efficiency as a facility display system. 
     The present invention has been accomplished in order to eliminate the above defect of the prior art, and intends to provide a drawing management device that can surely attain a user (operator)&#39;s objectives, i.e. has a function of displaying the object required by a user swiftly and exactly. This is because, where very detailed drawing information is not necessary, it is important to display only the drawing information within the range required by an operator as soon as possible, but not all of the items of the stored detailed drawing information. 
     SUMMARY OF THE INVENTION 
     An object of the present invention is to provide a drawing management device that can swiftly display drawing information with a degree of detail desired by an operator. 
     In order to attain the above object, a certain limit is given to the displaying time and priorities are automatically allotted to display objects located at several levels so that all necessary and a minimum amount of information can be displayed within a limited time. 
     The priorities of drawing data relative to the facility for water supply are automatically allotted at three to five levels. An operator updates the priority in sequence from history information with a changed display level, thereby to provide a desired drawing swiftly. 
     The above and other objects and features will be more apparent from the following description taken in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a block diagram of an arrangement of a drawing management device according to one embodiment of the present invention; 
         FIG. 2  is a block diagram for explaining the operation and function of the drawing management device according to the above embodiment; 
         FIGS. 3A and 3B  are views showing the relationship between drawing arrangements stored in a file device and graphic coordinate positions; 
         FIGS. 4A ,  4 B,  4 C and  4 D are views showing level arrangements of graphic data; 
         FIG. 5  is a view for explaining the priorities of display; 
         FIGS. 6A ,  6 B and  6 C are views showing examples of displayed drawings according to selected priorities; 
         FIG. 7  is a flowchart showing the processing flow in a priority display control unit; 
         FIG. 8  is also a flowchart showing the processing flow in a priority display control unit; and 
         FIGS. 9A and 9B  are views showing the graphic data capacity for each drawing and the three-dimensional shape of a retrieval icon corresponding to it, respectively; 
         FIG. 10  is a table for explaining the process of changing the priority allotted for each level number in accordance with the history of the operation of changing the level to be displayed; 
         FIG. 11  is a flowchart of the processing shown in  FIG. 10 ; 
         FIG. 12  is a flowchart of the process of making a display priority table in accordance with a display time; 
         FIGS. 13A and 13B  are a graph showing the distribution of the frequency for each level for each display time, and a graph showing the total time of display verses frequency. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring now to the drawings, an explanation will be given of one embodiment of the present invention. 
       FIG. 2  shows the basic arrangement for explaining the operation and function of one embodiment of the present invention shown in  FIG. 1 . 
     In  FIG. 2 , facility drawing data is stored in a file device  203 . The facility drawing data may include graphic or figure data of topography, tube (i.e., pipe) paths, and the like, and attribute data (the name of a town , the name of an individual, the diameter of a tube, the kind (e.g. vinyl) of the tube, etc.) expressed by characters and numerical values relative to the graphic representation. The graphic data to be stored in file device  203  is supplied from a drawing input device  204 , which operates in such a manner that a drawing drafted on a sheet of paper is scanned at regular intervals in accordance with the light and dark areas of the read data so that a digital image thus obtained provide encoded data. 
     The facility drawing may be composed of a plurality of drawings, such as shown in  FIG. 3A , which are individually separated to provide graphic data files. 
     The graphic data is expressed on rectangular coordinates as shown in  FIG. 3B . The lengths in the X and Y directions are determined by the size of the drawing concerned. This graphic data is expressed in such a way that it is separated in plural levels such as, a level  42  including road data  45  ( FIG. 4B ), a level  43  including house corner data ( FIG. 4C ) and a level  44  including tube path data  47  ( FIG. 4D ). The data located at these levels when superposed as required to provide the entire graphic data is shown as a level  41  ( FIG. 4A ). 
     On the other hand, the attribute data is supplied to the file device  203  from a data inputting device, which collectively supplies data from a keyboard  206  or a floppy disk  208 . 
     An operator manipulates a mouse  207  to display the drawing on a display device (CRT)  205  as follows. First, the operator manipulates the mouse  207  to move a cursor CU to one of a plurality of icons for selecting functions displayed on the CRT screen so that the function intended is specified. If the icon for ‘drawing retrieval’ is specified, a central processing unit (CPU) searches the drawing data concerned (composed of graphic data and related attribute data) to be temporarily stored in a main memory  202 . The main memory  202  operates to store the programs for executing the processings, such as search and editing of the drawing data, as well as the drawing data being processed. The drawing data temporarily stored in the main memory  202  is edited by the CPU  201  in accordance with the valid display coordinate that is a display region of the CRT  205 , and thereafter the edited data is displayed on the CRT  205 . The operator can recognize the contents of a desired or objective drawing from the displayed image. 
     Further, in order to recognize the details of the drawing, the image is displayed so as to be partially enlarged. To this end, the cursor CU is moved using the mouse  207  to specify any square region within the CRT display region in terms of ends of a diagonal line so that a part of the drawing is enlarged or reduced. Actually, a part of the drawing data concerned stored in the main memory  202  is edited in an enlarged or reduced way, and the drawing data thus edited is displayed on the CRT  205 . 
     An explanation will be given of the level display with priorities that permits a desired drawing to be displayed within a predetermined time. 
       FIG. 1  shows a block diagram of one embodiment of the present invention in which the CPU  201  executes the processing of level display with priorities. In  FIG. 1 , the display screen or field  101  is composed of an icon region  102  where the mouse is manipulated to select the function of retrieval or searching and displaying a desired drawing, and a drawing displaying region  103  where the drawing retrieved by mouse manipulation is displayed. The mouse  207  is used to select the function from the icon region  102  and to specify the location of the drawing to be displayed on the drawing displaying region  103 . The keyboard  206  is used to set the condition of searching a drawing. The data inputted from the keyboard  206  and the mouse  207  are supplied to an operation input unit  104  in the CPU  201 . The drawing data is previously stored in the file device  203 . 
     An explanation will be given of the relationship between the function of each of the functional units within the CPU  201 , and an operation of manipulation and display. 
     A desired drawing is retrieved or searched using an index drawing, drawing number, etc. and thereafter is displayed on the display device. The operation of the CPU  201  in such a display processing process will be explained below. First, using the mouse  207 , the item ‘drawing retrieval’ is selected or designated on the icon region  102  for mouse manipulation. This selective designation is inputted to a manipulation input section  104  thereby to activate a priority display control section  105 . The priority display control section  105  directs a graphic retrieval section  106  to retrieve the desired drawing (data). Further, when the level to be displayed in the graphic data retrieved from the graphic file  203  is changed, the priority display control section  105  serves to automatically change the priority level for the corresponding level on the display priority table previously defined in accordance with the changing history of the level concerned. Specifically, as shown in  FIG. 10 , the priority allotted for each level number is changed in accordance with the history of the operation of changing the level to be displayed. If the operation is directed to addition of the level to be displayed, the priority of the level number concerned is decreased by 1, and if it is directed to cancellation of the level to be displayed, the priority is increased. It should be noted that the amount of changing the priority must be limited in the range between a minimum value and a maximum value which are previously defined. 
       FIG. 11  shows the flow of the processings illustrated in  FIG. 10 . First, in step  1101 , when the operator initiates the operation of selecting the level to be displayed, the presence or absence of addition/cancellation of the level to be displayed is designated for the level number concerned on the display priority table. In step  1102 , the amount of changing the priority for each level number is calculated as −1 or +1 in accordance with the presence or absence of the addition/cancellation of the level to be displayed. In step  1103 , the priority due to the history of changing the level to be displayed is calculated on the basis of the above calculation result. In step  1104 , the priority after the history change is checked to see if it is within the allowable range. If it is within the allowable range, in step  1105 , the priority after the history changing is directly written in the display priority table. If it is outside the range, in step  1106 , where it is smaller than the minimum limit, the allowable minimum priority is written in the display priority table, and where it is larger than the upper limit, the allowable maximum priority is written in the display priority table. 
     The method of defining the display priority table of  FIG. 5  during a displaying time will be explained below.  FIG. 12  shows the process of making the display priority table of  FIG. 5  during the displaying time. First, in step  1201 , a table of the capacity of the graphic data for each level as shown in  FIG. 9A  is made for any drawing specified by the operator. In step  1202 , using the graphic data capacity table for each level, the time required for display is calculated on the basis of the amount of data displayed per unit time. In step  1203 , a graph ( FIG. 13A ) showing the distribution of the frequency for each level which depends on an individual time slot is formed. In step  1204 , a graph showing the total display time as shown in  FIG. 13B  is made on the basis of the above graph showing the distribution. In step  1205 , the display priority levels at e.g. five stages are successively allotted on the graph showing the total display time in accordance with the total display times. In step  1206 , the average display times corresponding to the display priority levels at five stages are calculated. Specifically, the total display time corresponding to each priority level is divided by its frequency to calculate the average display for each priority level. Finally, in step  1207 , a priority is allotted to the level corresponding to the average display time and the priority is written on the display priority table. 
     Returning to  FIG. 1  again, when the graphic retrieval section  106  has retrieved the drawing data, a priority display processing section  107  is activated. Then, the amount of data which can be displayed during the display time previously set by a user or operator is calculated, and the amount of data is reported to the priority display processing section  107 . The graphic retrieval section  106  retrieves the drawing data from the drawing files in the file device  203  on the basis of the number of the desired drawing and stores the retrieved drawing data in the main memory  202 ; it sends the data to the priority display processing section  107  immediately after retrieval of all the desired data has been completed. The priority display processing unit  107  takes in the drawing data and sequentially sends the drawing data at the level to be displayed to a display editing section  110  on the basis of a display priority table ( FIG. 5 ) and the amount of data to be displayed within the prescribed time. The display editing processing section  110  draws the desired drawing on the drawing display region  103  on the basis of the drawing data sent. 
       FIG. 5  shows display priority tables on which the numbers of levels and their priority are stored. In this table, the smaller number of priority is defined as having a higher priority, but may be defined in a way reverse thereto. 
       FIGS. 6A ,  6 B and  6 C show examples of drawings displayed for individual priorities.  FIG. 6A  shows a drawing  61  displayed with the priority of 1 in which the most important level group including a road  64 , a water supply tube path  65  and a symbol  66  on the water supply tube path  66  is displayed.  FIG. 6B  shows a drawing  62  displayed with the priority of 2 in which a house corner level  67  is superposed on the graphic data with the priority of 1.  FIG. 6C  shows a drawing  63  with the priority of 3 in which the level relative to water supply devices  67  is superposed on the graphic data with the priorities of 1 and 2. 
       FIG. 7  shows the processing flow in the priority display control section  105 . First, in step  701 , the amount of data that can be displayed during a prescribed display time t is calculated using the following equation:
 
D max =t×D 0   (1)
 
where D max : the largest amount of data which can be displayed during the time t
 
     t: prescribed display time 
     D 0 : the amount of data displayed during a unit time 
     In step  702 , the amount of displayed data corresponding to a priority i is calculated, and in step  703 , the request of data display with the priority of i is reported to the priority display processing section  107 . Finally, in step  704 , the total amount of displayed data up to the priority of i is calculated and the calculated amount of data is compared with the largest amount of data that can be displayed. If the former is within the range of the latter, the processing for the succeeding priority of i+1 is repeated. 
       FIG. 8  shows the processing flow in the priority display processing section  107 . First, in step  801 , the level corresponding to the priority of i is retrieved from the display priority table. In step  802 , the display data corresponding to the level concerned is retrieved from the graphic retrieval section  106  and the retrieval result is supplied to the graphic editing section  110 . 
     In this way, only the graphic data corresponding to the prescribed retrieval time can be automatically selected so that the drawing data with a high priority can be retrieved without being influenced by the complexity of the drawing concerned. 
     In designating the item ‘drawing retrieval’, in order to previously recognize the data capacity corresponding to the drawing data, a process reflecting the approximate data capacity of the drawing concerned on the icon to be retrieved will be performed as follows. 
     The mouse  207  is manipulated to move the cursor CU to the icon region  102  so that the icon of the item ‘capacity three-dimensional display’ is selected or designated on the icon region  102 . This selective designation is inputted to the manipulation input section  104  of the CPU  201 , and thereafter a request for the capacity of the three-dimensional display is reported to an icon three-dimensional display processing section  109 . In previously registering drawing data in graphic files of the file device  105 , a graphic data amount calculating section  108  calculates the capacity of the graphic data for each level and stores the calculation result on the main memory  202  as shown in  FIG. 9A . The icon three-dimensional display section  109  forms the icon shape on the basis of the total capacity of data calculated by the graphic data amount calculation section  108  using the table of graphic data capacities ( FIG. 9A ) on the main memory  202  in accordance with the level of the desired drawing to be displayed. As seen from  FIG. 9B , the icon shape is formed so that the depth of the three-dimensional icon corresponds to the capacity of the graphic data. The depth of the icon is converted from the maximum value of graphic data capacity previously defined as 100%. The three-dimensional icon is edited by the display editing section  110  as drawing data on the icon region  102  and the edited drawing data is displayed on the drawing display region  103 . 
     In this way, the approximate data capacity of the drawing can be easily determined from the icon shape prior to the drawing retrieval so that the time taken for the retrieval and data processing can be recognized swiftly and easily. 
     The present invention can be applied to a so-called navigation device mounted in a car which can quickly display road traffic information on a display device.