Abstract:
A combined computer-aided design (CAD) and analysis program includes a system inspector feature in a graphical user interface (GUI) that allows designers to identify a critical path among interconnected sets of components within a piping or a heating, ventilation, and air-conditioning (HVAC) system and provides pressure characteristics of the elements. This program provides visual feedback in an iterative design process.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention generally relates to computer graphics and applications, graphical user interfaces, and computer simulation and modeling. More specifically, the present invention relates to a computer-aided design (CAD) system for displaying characteristics of a system of interconnected components at different system locations. 
         [0003]    2. Description of the Related Art 
         [0004]    The term computer-aided design (CAD) generally refers to a broad variety of computer-based design tools used by architects, engineers, and other construction and design professionals. CAD systems allow users to create, manage, and share design data with integrated design and data management tools. Some CAD systems allow users to construct 3D models representing virtually any real-world construct, such as homes, offices, and other buildings. These CAD systems typically generate a variety of 2D and 3D views on a computer display, such as plan, profile, section, and elevation views. 
         [0005]    Traditionally, two separate programs have been used for the design and analysis of system designs. The first is a CAD system design program (for laying out building engineering systems) and construction documentation (for producing coordinated construction documents) for architects, structural engineers, and others. The second is an analysis program provided engineering data (for calculation, analysis, and sharing) for mechanical, electrical, and plumbing (MEP) engineers. Typically, a user develops a preliminary design on the CAD system. Then, the user transfers characteristics of the design from the CAD system to a separate analysis program to calculate engineering data, such as identifying flow rates and critical path segments of a system. The user then generates a new design using the calculated engineering data. Many subsequent iterations of design and analysis typically follow, until satisfactory cost, and efficiency constraints are achieved. 
         [0006]    Design characteristics and engineering data include various kinds of information related to building design and construction, including mechanical duct and pipe systems models, electrical lighting and power circuitry, electrical lighting calculations, plumbing system models, building support, structure support, and heating, ventilation, and air-conditioning (HVAC) energy and load analysis, and the like. In the iterative development of piping and/or HVAC systems, transferring characteristics of the design as input to the analysis program to calculate engineering data and, then, transferring calculated engineering data into a design program to generate a new design is a time-consuming and error-prone process. Much time may be lost refining a system design or updating numerous design characteristics and engineering data. An engineer or draftsperson typically wastes time performing tedious updating tasks and sometimes makes costly errors. For piping and/or HVAC systems, manual tasks might include identifying flow rates and critical path segments for a piping system, for example. 
         [0007]    Accordingly, design and construction professionals need a CAD system that provides combined design and analysis to eliminate the time that is currently spent manually transferring and entering data between separate design and analysis program in an iterative process. This would minimize tedious updating tasks and costly errors and improve productivity, accuracy, and coordination between design and construction teams. 
       SUMMARY OF THE INVENTION 
       [0008]    The present invention is directed to methods and computer program products that minimize tedious updating tasks and costly errors, and improve productivity, accuracy, and coordination between design and construction teams by displaying characteristics of a system of interconnected components at different system locations. 
         [0009]    One embodiment of the invention is a method for displaying characteristics of a system of interconnected components at different system locations. The CAD system detects a location of a pointing device, calculates a characteristic of the system at the detected location, and displays the calculated characteristic of the system. The calculated characteristic may be a critical path among the interconnected components. The displayed characteristics may include a flow rate or a pressure loss. The CAD system may display an updated calculated characteristic of the system in response to receiving a change to the system of interconnected components. In one embodiment, the interconnected components comprise a set of components. The change may comprise splitting one of the sets of components into two or more sets or joining two or more sets of components into one set. One set may comprise components with one or more common transmission parameters. 
         [0010]    Another embodiment of the invention is a computer-readable medium containing a program which when executed by a processor, performs the above method. 
         [0011]    Another embodiment of the invention is a method for interacting with a display of interconnected components. The user positions a pointing device over a first position to cause a display of a first characteristic of the interconnected components at the first position. The user positions a pointing device over a second position to cause a display of a second characteristic of the interconnected components at the second position. The first characteristic of the system may be a critical path among the interconnected components. The second characteristic may be a flow rate. The user may also make a change to the interconnected components to cause a display of an updated calculated characteristic of the system. 
         [0012]    Advantageously, by displaying characteristics of a system of interconnected components at different system locations, the CAD system eliminates the time users currently spend manually transferring and entering data between separate design and analysis program in an iterative process. This minimizes tedious updating tasks and costly errors and improves productivity, accuracy, and coordination between design and construction teams. 
     
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]    So that the manner in which the above recited features of the present invention can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only exemplary embodiments of this invention and are therefore not to be considered limiting of its scope, for the claimed invention may admit to other equally effective embodiments. 
           [0014]      FIG. 1  is a 3D view of an exemplary ductwork system generated in accordance with an embodiment of the present invention. 
           [0015]      FIG. 2  is a 3D view that illustrates supply and return subsystems of the exemplary ductwork system of  FIG. 1 . 
           [0016]      FIG. 3  is a 3D view that illustrates analysis information for a component of the exemplary ductwork system of  FIG. 1 . 
           [0017]      FIG. 4  is a 3D view that illustrates analysis information for the exemplary ductwork system of  FIG. 1 . 
           [0018]      FIG. 5  is a 3D view that illustrates how the exemplary ductwork system of  FIG. 1  is divided into sections. 
           [0019]      FIG. 6  is a 3D view that illustrates sections of the exemplary ductwork system of  FIG. 1 . 
           [0020]      FIG. 7  is a 3D view that illustrates a critical path of the exemplary ductwork system of  FIG. 1 . 
           [0021]      FIGS. 8A and 8B  show a graphical user interface for changing the size of one or more ducts in the exemplary ductwork system of  FIG. 1  according to one embodiment of the present invention. 
           [0022]      FIG. 9  is a 3D view that illustrates resulting analysis information in response to the change shown in  FIGS. 8A and 8B  to the exemplary ductwork system of  FIG. 1 . 
           [0023]      FIGS. 10-13  illustrate how a change to the exemplary ductwork system of  FIG. 1  results in the splitting of a section into two or more sections. 
           [0024]      FIG. 14  is a block diagram of a networked computer environment in which systems and methods according to embodiments of the present invention may be implemented. 
           [0025]      FIG. 15  is a flow chart of an exemplary method of displaying characteristics of a system of interconnected components at different system locations according to one embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0026]    One exemplary embodiment is a CAD system that displays characteristics of a system of interconnected components at different system locations. The CAD system includes a combined design and analysis program. The present invention applies to a broad variety of design and analysis features beyond those incidentally described herein. Although the detailed description describes the CAD system in the context of an exemplary ductwork system, the present invention applies to representations of virtually any real-world construct, such as electrical, mechanical, architectural, or structural elements, or and other kind of design or construction elements for homes, offices, and other buildings or structures. 
         [0027]      FIG. 1  is a 3D view  100  of an exemplary ductwork system that has been generated in accordance with an embodiment of the present invention. In this example, the ductwork system includes supply terminals  102 , return diffusers  104 , an air-handling unit  106 , and network of ducts  108 ,  110 . Four supply terminals  102  are connected with a first network of ductwork  108  to an air-handling unit  106 . Two return diffusers  104  are connected with a second network of ductwork  110  to the air-handling unit  106 . A CAD system displays 3D view  100  and provides combined design and analysis.  FIG. 1  illustrates the design aspect of the CAD system, which includes displaying 3D connectivity information, among many other design features. 
         [0028]      FIG. 2  is a 3D view  200  of the exemplary ductwork system of  FIG. 1  that has been generated in accordance with an embodiment of the present invention.  FIG. 2  highlights the difference between the supply subsystem  202  and the return subsystem  204 . The supply subsystem  202  includes the supply terminals  102  and the first network of ductwork  108 , while the return subsystem includes the return diffusers  104 , the second network of ductwork  110 . The air-handling unit  106  is a member of both the supply and return systems. The user may select a subsystem to analyze. In  FIG. 2 , the supply subsystem  202  has been selected for analysis and is displayed in a visibly different way than the inactive return subsystem, which was not selected for analysis. Other embodiments may display active subsystems in different ways. 
         [0029]      FIG. 3  is a 3D view  300  of the exemplary ductwork system of  FIG. 1  that has been generated in accordance with an embodiment of the present invention.  FIG. 3  shows some analysis information. The CAD system provides combined design and analysis. As part of the analysis, the CAD system provides a system inspector feature in a graphical user interface (GUI), which may be implemented in a software application or software module. The user may enable or disable the system inspector using the GUI. The system inspector performs analysis information (e.g., flow and data calculations) for a system (e.g., the exemplary ductwork system) or a subsystem (e.g., the supply  202  or return  204  subsystem). For example, the system inspector may calculate a critical path. The critical path is the path through the system or subsystem that has the most pressure losses. Pressure losses may vary depending on the length of the path, airflow, size of ducts, and anything that causes additional airflow friction. The critical path is the path through the system that consumes the most energy. As a result, a designer often attempts to generate a new design that is more efficient and lower cost. The CAD system facilitates an iterative design and analysis process, among other uses. 
         [0030]      FIG. 3  shows part of the critical path  306  in a dotted line and other paths  302 ,  304 ,  308  in dashed lines. In one embodiment, the critical path is displayed in red, while the other paths are displayed in blue. Other embodiments may display these paths in various other ways, such as shading components. In a preferred embodiment, the critical path and other paths are displayed continuously, when the system inspector is enabled. Other embodiments may display the paths differently, such as only when the user positions a pointing device near a system component. When the user positions a pointing device  308  (e.g., mouse, trackball, or any device capable of moving the cursor on the display) over a component  310  of the supply subsystem, the system inspector provides additional analysis information  312  for display near the component  310 . In other embodiments, a user may view analysis information for a component in various other ways, such as in a separate window. As shown in  FIG. 3 , the analysis information  312  includes a section number of 11, a flow rate of 500 cubic feet per minute (cfm), a static pressure of 0.04 inch water gauge (in-wg), and a pressure loss of 0.07 in-wg. Other embodiments may provide different information suitable to the type of system under analysis. 
         [0031]    Each supply terminal  102  ( FIG. 1 ) is associated with a quantity of airflow to be provided to a room. The CAD system propagates this information throughout the interconnected components of the duct system. The system inspector divides the system into a number of sections by analyzing all the components of the system and their interconnections and numbers the sections. A section is a collection of connected elements that share one or more characteristics or properties, such as flow rate, friction, or size. Other embodiments may designate sections differently, such as with letters or names. In one embodiment, the system inspector may number the sections sequentially or order the sections by some property or characteristic. 
         [0032]      FIG. 4  is a 3D view  400  of the exemplary ductwork system of  FIG. 1 .  FIG. 4  illustrates additional analysis information. When the user positions the pointing device  308  over or near a supply terminal  102 , the CAD system displays two lists of information. A brief section identification list  402  and a more lengthy engineering data list  404 . In one embodiment, the section identification list  402  is displayed for a limited time period, while the engineering data list  404  is displayed so long as the pointing device is near the component. The present invention is not limited to any particular kind or amount of engineering data and may include any data related to the system being analyzed. The present invention is also not limited to any particular kind or amount of information in the section identification list so long as it identifies a section in some way. For example, the section identification may be in graphical form rather than textual form. Engineering data may also be in graphical or other forms. 
         [0033]      FIG. 5  is a 3D view  500  of the exemplary ductwork system of  FIG. 1  that has been generated in accordance with an embodiment of the present invention.  FIGS. 4 and 5  illustrate the system inspector dividing the supply terminal  102  and the connected duct network  502  into different sections (i.e., section  4  in  FIG. 4  and section  16  in  FIG. 5  respectively), even though the components  102 ,  502  are adjacent to one another. In  FIG. 5 , duct network  502  is in section  16 , which includes three components, a vertical duct  508 , an elbow  510 , and a horizontal duct  512 . The user may move the pointing device quickly over different components, checking the brief section identification list  504  to see how the system inspector has divided the system into sections. The user may use the engineering data list  506  for revising the design or for other purposes. 
         [0034]      FIG. 6  is a 3D view  600  of the exemplary ductwork system of  FIG. 1  that has been generated in accordance with an embodiment of the present invention.  FIGS. 4-6  illustrate that different sections (i.e., sections  4 ,  16 , and  9 ) have at least one different characteristic, such as pressure loss (i.e., 0.00, 0.12, and 0.01 in-wg), even though the components (i.e., supply terminal  102 , vertical duct  502 , and horizontal duct  602 ) are connected and adjacent. Typically, there are different sections on each side of a “T” location, because the flow changes (i.e., 500 cmf to 1100 cfm from section  16  to section  9 ). 
         [0035]      FIG. 6  shows a third section (i.e., section  9 ).  FIG. 6  illustrates that when the user moves the pointing device over or near a section, all of the components in the section are visually distinguished. In  FIG. 6 , the user positioned the pointing device  308  near the horizontal duct  602 , causes the CAD system to display a section identification list  604  and an engineering data list  606 . In addition, the CAD system makes the horizontal duct  602  visually distinct by increasing the line thickness of the horizontal duct  602 , because section  9  contains this one component. By contrast, section  16  (shown in  FIG. 5 ) contains three components, i.e., the duct network  502  includes vertical duct  508 , elbow  510  and horizontal duct  512 . The duct network  502  is also visually distinct. Other embodiments may make components in a section visually distinct in various ways, such as using shading, color, textual information, and the like. In one embodiment, every component in a system may be visually distinct at the same time. 
         [0036]      FIG. 7  is a 3D view  700  of the exemplary ductwork system of  FIG. 1  that has been generated in accordance with an embodiment of the present invention.  FIG. 7  shows a critical path  706  that is not the longest path through the ductwork system. When the user moves the pointing device  308  near the components in one of the sections along the critical path to investigate, the CAD system displays a section identification list  702  and an engineering data list  704  for section  16 , which contains three interconnected components  508 ,  510 ,  512 . The engineering data list  704  indicates that there is a large loss, i.e., 0.12 in-wg in section  16 . 
         [0037]      FIGS. 8A and 8B  show a graphical user interface  800  for changing the size of one or more ducts that has been generated in accordance with an embodiment of the present invention.  FIG. 8A  illustrates that the CAD system includes different sizing methods and that the current size of the duct network  502  in section  16  is the size required for a velocity of 1,000 feet per minute (fpm).  FIG. 8B  illustrates the user changes the size by changing the required velocity to 800 fpm, attempting to reduce the loss in section  16  and, as a result, change the critical path.  FIGS. 8A and 8B  illustrate one way the user may perform both design and analysis at the same time using the CAD system. Other embodiments include changes to other properties or characteristics, such as changing the shape or size of a duct or other changes in design, such as adding (or removing) a component to (or from) the system.  FIG. 9  illustrates the results of the change. 
         [0038]      FIG. 9  is a 3D view  900  of the exemplary ductwork system of  FIG. 1  that has been generated in accordance with an embodiment of the present invention. As shown in  FIG. 9 , the duct network  502  is no longer along the critical path. Engineering data list  902  for section  19  containing the duct network  502  now indicates that the pressure loss is 0.07 in-wg. In  FIG. 9 , the CAD system provides the user with feedback, e.g., analysis data changes in response to the design change. Traditionally, two separate programs have been used for the design and analysis of system designs. Thus, embodiments of the present invention minimize tedious updating tasks and costly errors and improve productivity, accuracy, and coordination between design and construction teams by displaying characteristics of a system of interconnected components at different system locations. 
         [0039]      FIGS. 10-13  illustrate how a change to the system results in the system inspector splitting a section into two or more sections.  FIGS. 10-13  are 3D views  1000 ,  1100 ,  1200 ,  1300  of the exemplary ductwork system of  FIG. 1  that has been generated in accordance with an embodiment of the present invention. Duct network  1002  contains three system components: vertical duct  1004 , elbow  1006 , and horizontal duct  1008 . Section  11  contains these three components.  FIG. 11  illustrates the components after the user made a change to the shape of horizontal duct  1008 , i.e., from rectangular to circular.  FIGS. 12 and 13  illustrate that section  11  now contains only horizontal duct  1008  while new section  17  contains elbow  1006  and vertical duct  1004 . The system inspector splits section  11  into two sections, i.e., new section  11  and section  17 . Similarly, a change to the system may result in the system inspector joining two or more sections into one section. 
         [0040]      FIG. 14  is a block diagram of a computer environment  1400  in which systems and methods according to embodiments of the present invention may be implemented. One embodiment of the computer environment  1400  includes a computer  1410  (e.g., personal computer (PC)) programmed as a standalone, single workstation operating the CAD system and having conventional output devices, such as a computer display or a printer for generating the annotation graphics in 2D form. The CAD system software  1432 , which runs on the processor  1411 , includes both a design component  1434  and an analysis component  1436 . Traditionally, two separate programs have been used for the design and analysis of system designs. By contrast, embodiments of the present invention eliminate the time that is currently spent manually transferring and entering data between separate design and analysis program in an iterative process. This minimizes tedious updating tasks and costly errors and improves productivity, accuracy, and coordination between design and construction teams. 
         [0041]    Another embodiment of the computer environment  1400  includes a server computer  1410  and a number of client computers  1420  (only two of which are shown). A computer network  1430  (e.g., a local area network (LAN)) connects the server computer  1410  and the client computers  1420 . The components of the server computer  1410  that are illustrated in  FIG. 14  include a processor  1411  and a system memory  1412 . The server computer  1410  is connected to a mass storage unit  1413  that stores the contents managed by the server computer  1410 . Each client computer  1420  includes conventional components of a computing device, e.g., a processor, system memory, a hard disk drive, input devices, such as a mouse and a keyboard, and output devices, such as a monitor (not shown). The server computer  1410  is programmed to operate as a network server that communicates with the client computers  1420 . 
         [0042]    In another embodiment, the server computer  1410  is programmed as a web server that communicates with the client computers  1420  using the TCP/IP protocol, and hosts a web site that can be accessed by the client computers  1420 . The client computers  1420  are programmed to execute client programs to access the CAD system as a service provided by the server computer  1410 . The server computer  1410  manages the content stored in the mass storage unit  1413  using a database management system. The contents include elements of CAD drawings, designs, 3D models, and 2D views, analytical models, engineering data, such as fluid flow, and other data. 
         [0043]      FIG. 15  is a flow chart of an exemplary method  1500  of displaying characteristics of a system of interconnected components at different system locations according to one embodiment of the present invention. At  1502 , the CAD system detects a location of a pointing device. At  1504 , the CAD system displays characteristics (e.g., flow rate or a loss) of a component at the location. At  1506 , the CAD system calculates and displays a characteristic (e.g., critical path) of the system. At  1508 , the CAD system detects a change to the components and displays updated characteristics by repeating steps  1502 - 1508 . Other embodiments may perform the steps in a different order or perform additional steps.  FIG. 15  illustrates how the CAD system incorporates both design (step  1508 ) and analysis (steps  1504  and  1506 ) and facilitates an iterative process of design and analysis in a single CAD system. 
         [0044]    While particular embodiments according to the invention have been illustrated and described above, those skilled in the art understand that the invention can take a variety of forms and embodiments within the scope of the appended claims.