Method and apparatus for developing application software for automation systems

[0002] This application is a continuation-in-part of application Ser. No. 09/103,210 filed Jun. 23, 1998 in the name of Frank Meyer, now U.S. Pat. No. 6,061,602, Sep. 25, 2000, the entire contents of which are incorporated herein by reference.

[0003] This invention relates, in general, to methods and apparatus for interactively developing a graphical control flow structure and associated application software for home automation systems.

[0004] Description of the Art

[0005] The operation of industrial machines and processes are typically controlled by a central controller, such as a programmable logic controller or PLC. Basically, a PLC includes a processing unit with a control program stored in a memory, input modules and output modules. The processor, when executing the control program, will control the operative state of the various outputs, typically “on” or “off”, in response to the detection of various external inputs. Such PLCs typically include a unique programming language, such as ladder logic or Boolean, which are fairly common in the industrial machine industry.

[0006] Various programming standards have been developed for use in developing application programs for PLCs. Grafcet is a graphical programming language originally developed by AFCET (Association Francais Pour La Cybernetique Economique et Technique) and has now become an international PLC programming language. IEC 1131 is a standard established by the International Electrotechnical Commission that specifies the syntax and semantics of a unified suite of programming language for programmable logic controllers. Part of the standard refers to sequential function charts that is Grafcet like in structure.

[0007] Other control software is also available. ActiveX Controls is a name defined by Microsoft Corporation for programmable elements. An ActiveX control is an object that when instantiated embodies both specific data and the functions that manipulate it. The ActiveX control or component is an entity that has state, behavior and identity. An object's state consists of its attributes or properties and the attributes' current values. An object's behavior consists of the operations or methods that can be performed on it and the accompanying state changes. An object's identity is what is used to distinguish it from other objects. An ActiveX component has events that inform when something-has happened. In general, each ActiveX component can have methods, e.g., grinding, inspecting, etc., properties, e.g., grinding speed, number of passes, etc., and events, such as grinding complete. An instantiated ActiveX control is one which has been created as opposed to being simply known about. A computer program may know what ActiveX controls are available, but only when it creates one of these controls does it exist, e.g., it is instantiated. The same control may be instantiated many times or just once. Several methods can be called on any instantiated control.

[0008] In developing any application program, the program developer typically generates written code using various symbols or instructions required by the particular software program. However, syntax errors are frequent when developing such code. These errors must be found and corrected which increases the amount of program development time. The use of graphical based languages, such as Grafcet and its IEC 1131 subset, avoid the actual writing of code and enable an application developer to establish the parameters of the application process through the use of graphical symbols.

[0009] Attempts have also been made to combine graphical-control or standards languages with other software programs to enable an application developer to quickly and easily develop graphical based application software for use in a particular application. U.S. Pat. No. 5,742,504, of which the present applicant is a co-inventor, describes a method and system for quickly developing application software for use in a machine vision system. Commands and sets of instructions are received from a user to select a first custom control program of desired machine vision components, desired hardware operating parameters of the hardware and a second custom control program of desired machine vision algorithms. The first control program is linked with the desired hardware operating parameters to the second control program to form the application software. Attempts have also been made to develop graphical control-flow application software for use in a machine vision system by interactively linking the ActiveX standard with Grafcet or its IEC 1131 subset to enable an application developer to develop graphical-flow application software for a machine vision system. However, such attempts to generate graphical-flow application software have been restricted solely to the machine vision industry.

[0010] Scripting engines have become widely adopted with the emergence of Web Browsers. Various scripting languages are available, including VBScript, JScript, JavaScript, and ECMAScript. It would be desirable to automatically adapt such scripting languages or programs into application software for automation control systems.

[0011] Thus, it would be desirable to provide a method and apparatus for interactively developing application software for use in industrial automation or home automation applications where the application software developer utilizes a graphical image sequence without the need to write alphanumeric code. It would also be desirable to provide a programmed computer which queries the user's intentions and guides the user's choices until the particular application software is developed. It would also be desirable to provide a method and apparatus for interactively developing application software for use in industrial and home automation wherein the method and apparatus integrate standard third party controls, such as ActiveX controls, with a graphical programming language, such as Grafcet. It would also be desirable to provide a method and apparatus for interactively developing application software for use in automation systems wherein mathematical expressions can be defined in scripting language which can be incorporated as a step in the software development. It would also be desirable to provide a method and apparatus for interactively developing application software which is capable of responding to external events where the source of the event or its properties are not known.

[0012] The present invention is an apparatus and method for interactively developing a graphical control application software program for use in controlling an automation apparatus or process.

[0013] In one embodiment, the apparatus includes means for storing an application development program including a first program representing a first set of flow sequences for operating an automation apparatus sequences. Means are provided for storing a plurality of controls for use in the automation apparatus. A display displays graphical representations of the flow sequence in the first program and the controls. A computer processor means receives commands from a user to select one of the flow sequences from the first program and one control. The display displays a structure wherein the graphical representation of the selected flow sequence is a step in the structure and the selected control is mapped into the structure at a step. Each step is redefined as including a scripting language step or a mathematical expression variable. The displayed structure also has at least one transition and at least one action. Each transition may also be a scripting language transition or a mathematical expression variable, or an event triggered by an external source not known to the application program. Means are also provided for linking the first program with the controls to form an application program in response to user commands without the need for writing program codes.

[0014] The present invention also contemplates a method for developing a graphical control program. In this embodiment, the method comprises the steps of:

[0015] storing a first control program representing a first set of flow sequences for use in operating an automation apparatus, the flow sequence including at least one transition and at least one step;

[0016] storing a plurality of controls as objects for use in the automation apparatus;

[0017] setting characteristics of the objects in the selected flow sequence as having one of a plurality of selectable methods, one of a plurality of selectable properties, and one of a plurality of selectable stored events for each selected object;

[0018] redefining each step in each flow sequence as one of an object, a mathematical expression and a scripting language set;

[0019] displaying graphical representations of the object;

[0020] receiving commands from a user to select one flow sequences from the first control program and to select one object;

[0021] linking the first control program with the object; and

[0022] displaying a graphical flow structure wherein the graphical flow structure includes the selected control mapped into the selected object mapped into the selected flow sequence and having at least one transition and at least one event, each transition adapted to be linked with at least one of an event and a property of an object.

[0023] The present apparatus and method enables an application developer to generate an application program to control an automation process, such as an industrial automation apparatus or process and a home automation process. The present invention uniquely combines a control program defining component standards with hardware suited for a particular automation application and a graphical flow program which prompts the user in generating the graphical flow sequence step by step and mapping into the sequence selected hardware and hardware operating parameters.

[0024] The various features, advantages and other uses of the present invention will become more apparent by referring to the following detailed description and drawing in which:

[0025] FIG. 1 is a pictorial representation of an exemplary hardware configuration on which the present invention can be implemented;

[0026] FIG. 2A is a pictorial representation of a programming menu containing home automation hardware icons representing the controls of the present inventions;

[0027] FIG. 2B is a pictorial representation of a programming menu containing the flow sequences in the first program;

[0028] FIGS. 3, 4 and 5 are sample control programs developed in accordance with the teachings of the present invention;

[0029] FIG. 6 is a sample control program developed in accordance with another aspect of the present invention; and

[0030] FIG. 7 is a sample control program showing the features of the present invention.

[0031] Referring now to the drawing, and to FIG. 1 in particular, there is depicted a computer system 10 on which the method and apparatus of the present invention can be implemented. The computer system 10 includes a central processing unit or CPU and a memory contained within a housing 12. A conventional monitor 14, keyboard 16 and pointing device 18, such as a mouse are connected to the CPU. A magnetic storage device 20 is also mounted in the housing 12.

[0032] The CPU and memory provides the development environment of a graphic, flow control language, such as Grafcet, for pictorially illustrating the sequence and interaction of an industrial automation system or a home automation system, for example.

[0033] FIGS. 2A and 2B illustrate various menu selectable icons which appear on the monitor 14 and which represent home automation hardware forming a set of controls and flow sequences forming a first program.

[0034] The following hardware is illustrated for a home automation application. It will be understood that different hardware icons may be provided for different applications, such as an industrial automation or machine control process.

[0035] As shown in FIG. 2A, the icons, as displayed on the display 14, include a security monitor icon 30, a nighttime icon 32, an alarm symbol 34, an alarm clock or timer 36 indicating wake-up or a morning time, a garage door icon 38, a light icon 40, a furnace oil pump icon 42, a furnace blower icon 44, a false repair icon 46 and a furnace ignitor icon 48. Other icons are also possible, for a home automation application. The icons or controls 30-48 shown in FIG. 2A may be used as ActiveX custom controls to interactively develop industrial automation or home automation applications or software programs in the Grafcet/IEC 1131 programming language.

[0036] In use, the industrial automation or home automation application is created by placing the custom controls or icons 30-48 in a menu. The properties for each of the controls or icons are then established. For example, each custom control has methods, such as timing, igniting, etc., properties, such as temperature, state, etc., and events, such as door closed, time of day, ignitor on, etc.

[0037] According to the present invention, Grafcet and/or its subset derivative IEC 1131 programming standard, is married together with the ActiveX standard to produce a programmable software or application program development system that does not require the use of standard software programming code. This provides the advantage of allowing any ActiveX component, such as any of the components 30-48 shown in FIG. 2A, to be inserted by a program developer within an environment that is particularly suited for a particular automation application, such as an industrial machine control application or a home automation application. Interrogation of the properties, methods and events of these ActiveX components can be used by the program developer to generate the control software without the use of any standard programming code. Properties and data of these controls can be exchanged between the various joined standards or programs.

[0038] The program developer can configure the application method and apparatus of the present invention by either a drag and drop or a menu system. The system of the present invention queries the programmer's intentions, and guides the programmer's choices until the application is fully developed.

[0039] The Grafcet language or program used in the present invention includes steps, transitions and actions. A step is represented by a box with a number or other symbol in it identifying the step or an icon selected from the menu in FIG. 2B.

[0040] Within the Grafcet/IEC 1131, each step in a Grafcet sequence represents a stable situation in an automation process and has one or more actions associated with it. It has been redefined in the present invention to represent an ActiveX component. Further, any of the complete Grafcet programs or sequences shown in FIGS. 3-5 and described hereafter can be, according to the present invention, redefined as a single ActiveX control.

[0041] In another aspect of the present invention, a step is redefined as a script step. A script is a high level computer language that can control an object from within an application program. Its typical syntax is [Object].[Method or Property]. As shown in FIG. 6, in the case of a method, this syntax would read “Conveyer.Move”. In the case of property, its value would be received or set as “Conveyer.Speed”.

[0042] Scripting languages have become more widely used through the emergence of Web Browsers. Typically, scripting languages include BScript, VisualScript, JScript, JavaScript, and ECMAScript.

[0043] In the present apparatus and method, a step can be a scripting step using any of the scripting languages described above. Within this step, the user will have access to all of the system and step components, as well as their methods and properties, i.e., variables. Thus, a piece of standard code, such as Basic, or other code based language, can be inserted as a step in the present method and apparatus. As such, a step is not only a Corn object, but a piece of software written by the user in one of the standard scripting programing languages to control the set of properties of an object.

[0044] An example of a scripting step to control the conveyer in FIG. 6 would be:

[0045] Conveyer.Move

[0046] Conveyer.Speed=20 mm/sec

[0047] Conveyer.Acceleration=1 mm/sec/sec

[0048] According to this aspect of the invention, the properties of an object are accessed and set via a scripting language.

[0049] As shown in FIG. 2B, the Grafcet program includes a number of selectable flow sequences, each including a transition and a step, with alternate conditional branches and parallel branches being possible as shown in FIG. 2B. A transition indicates the possibility of evolution from one step to the next. Within each transition there is an associated receptivity which is a function of input or variables or ActiveX controls. A transition in the Grafcet standard can be either a true state, an event generated by an ActiveX control, i.e., an ActiveX trigger control or a Boolean expression defined by an internal variable or properties of any control. Each transition is represented by a short horizontal bar across a vertical line.

[0050] One transition is provided automatically after each step. For example, a transition is either an event coming from an ActiveX control or a boolean expression which compares internally defined variables or properties of any instantiated control.

[0051] Examples of boolean expressions are:

[0052] Time>3 pm

[0053] ActiveXControl.property It>10

[0054] ActiveXControl.result<=cos(Another Active Control.property*2+10) i.e. these expressions return true or false.

[0055] With each step, there are associated actions. Actions are typically application dependent, such as switching on the light, starting the furnace blower, starting an engine, starting a delay, incrementing or decrementing a counter, or any other operation.

[0056] Transitions may also be defined using scripting language as discussed above. An example of a scripting transition would be: If(Gauge.Result<Value). If the above statement is true, the transition is set to true. This enables the properties of an object to be accessed via a scripting language to set the value of a transition.

[0057] In the above-described aspect of the invention, a transition has been based on an event activated by an object defined in the programming environment or the result of a test on the value of an expression. According to another aspect of the present invention, a transition is also redefined to be an event activated by an object which is not part of the programming environment. These events would be registered to the operating system or to the programming environment. Hence, the transition will receive the event, but would not necessarily know the source of the particular event.

[0058] For example, two computers are connected in a network or the computer utilizing the software program of the present invention is connected to the network. The software program is provided in a computer to enable the computer to continually analyze and watch the stock market using certain stock market parameters, such as price trend data and/or selling volume data. The computer software is programed to generate an alarm signal upon the occurrence of a certain event, such as if the price of the DIJA falls by more than X percent or the volume of trading in any DIJA company is selling more than X percent of its stock. The present application software does not know where these computers or the processes are which they are watching. The present application program would wait for the alarm event and then carry out any programed actions, such as three things which will occur in parallel, by example only. As shown in FIG. 7, the three programmed actions include selling of stock, flashing warning messages to a display monitor and sending a prerecorded message to a designated phone number.

[0059] Thus, according to the present invention, programming of a particular application sequence takes place through a graphical user interface. Existing ActiveX controls are integrated or linked into a Grafcet sequence. The step in the Grafcet standard has been redefined to also be an instantiated ActiveX control. Traditionally, a step in the Grafcet standard was an output. Thus, a transition has been redefined to include events from an ActiveX control or a boolean expression that compares properties of ActiveX controls.

[0060] In one example of creating a Grafcet control sequence according to the present invention, the developer or user selects one of the icons from the icon menu shown in FIG. 2A and drags and drops the selected icon 30-48 into a sequence display area on the monitor 14. FIG. 3 depicts an evening-morning graphical sequence. Transition and flow lines are selected from the menu shown in FIG. 2B and inserted into an initial one step loop to develop a flow chart that obeys the Grafcet programming rules.

[0061] When inputs are required before transitioning to a next step, the user is prompted through a message displayed on the monitor 14 which also highlights or otherwise indicates the position for insertion of the input. The user selects inputs in the same way as the icons are selected, that is, for example, by dragging and dropping the selected input into the graphical sequence. Outputs from each step will be shown automatically.

[0062] The user may also insert a parallel or conditional branch from the Grafcet menu into the sequence as shown in FIGS. 3-5.

[0063] As shown in FIG. 3, from an initial step, control switches through a conditional branch represented by a single horizontal line to either a morning or evening/bedtime sequence. This requires a time input to trigger one of the morning sequence or the bedtime sequence. In the bedtime sequence, a transition occurs to the next step in which a lights out event takes place. Subsequently, the next step occurs without a transition wherein garage door is closed.

[0064] In the corresponding morning sequence, control automatically advances to a step in which the garage door is opened.

[0065] FIG. 4 depicts a typical security control program which can be generated using the combined Grafcet/ActiveX controls. When a security monitor step 60 is selected, control conditionally branches to one of a no alarm sequence branch or an alarm sequence branch. Obviously, the no alarm transition branch takes no further action. When an alarm transition input is detected, two branches take place simultaneously or in parallel as shown by the double horizontal lines in FIG. 4. First, an alarm signal is generated typically by telephone to the police, security company, etc. Simultaneously, a security lights on action is generated.

[0066] A more complex furnace control sequence is shown in FIG. 5. When an input indicating that a room or home temperature requires heating to elevate the temperature to a selected preset or selected temperature, a first branch is selected and two actions take place in parallel or simultaneously, such as turning both the furnace oil pump and the furnace blower ignition. Next, a parallel path is selected wherein the temperature of the furnace bonnet is compared with the temperature at the blower. If the temperature in the bonnet is greater than the bonnet temperature at the blower, the blower is turned on in step 70. If the temperature is less than the temperature at the blower, the blower is turned off in step 72.

[0067] In a third branch, if the temperature of the furnace bonnet is less than the temperature at the blower and the furnace oil pump has been on for more than 60 seconds, a simultaneous branch takes place resulting in two parallel or simultaneous actions, such as turning off the oil pump and turning off the furnace ignition. In this sequence, a fault repair signal 46 is generated in the next step.

[0068] Math controls, not shown, are also possible in the combined Grafcet/ActiveX system of the present invention. A math step allows the definition of variables and expressions that set the values of these variables. Such variables are either numeric or Boolean and can be set to some mathematical function of other variables or properties of ActiveX controls or some combination thereof.

[0069] In one aspect of the invention, system variables can be used at any other step to assign properties to some value, or at any transition to test a condition against a predefined variable. These variables can compute mathematical expressions based on properties or results. Hence, the definition of these mathematical expressions can be as part of a step, or as part of the programming environment. These mathematical expressions can be defined in scripting language, as described above or via a software wizard which guides the user to build a new variable without any knowledge of a scripting language.

[0070] An example of a mathematical expression would be:

[0071] area=Guage.Result×PI

[0072] Hence, a variable called “Area” is now available to all other steps and transitions. A math expression table allows the user to define system variables which can be an expression. An expression is any mathematical statement that accesses objects and properties. These expressions can be written in a scripting language or in a wizard thereby giving the user access to objects and their properties in a control led fashion.

[0073] Another example of the combined use of a math expression table and scripting language is shown in FIG. 6. A scripting step is programmed as shown in FIG. 6 to establish the tolerance of the gauged part. The scripting language access a Cad drawing of the measured part to determine the desired tolerance. The math expression is then employed to establish the tolerance and a warning tolerance. These steps are shown in FIG. 6 as part of the scripting step.

[0074] Program control then branches to three events: “Gauge.Result<WarningTolerance”,“Gauge.Result<Tolerance” and “Gauge.Result=Failed”. In the first event, the conveyer will still be allowed to transition to the next step to accept the part. In the second event, the step first activates a warning light and then transitions to a next step for the conveyer to move to accept the part. Only when the “Gauge.Result” is greater then the tolerance is a failed signal generated causing the application program to parallel branch to a conveyer move to reject the part as well as to log the rejected part.