KR100372142B1 - Crane control system and communication method having integral network - Google Patents

Abstract

PURPOSE: A crane control system having an integral network is provided with an MMI system communicating with a central controller. CONSTITUTION: An MMI system(100) is provided to input control program, monitor input/output signal and data. A central controller(110) analyzes the inputted control program of the MMI system to control whole system in real time. A direct input/output device(130) is connected to the central controller by a bus. A network driver(120) is connected to the central controller to drive and control network. A remote input/output device is connected to the network driver. A PLC(140) is connected to the network driver and to a motor.

Description

Crane control system and communication method with integrated network

The present invention relates to a crane control system, and more particularly, to a crane control system having an integrated network, an MMI system constituting the control system, and a communication method for a central control period.

In general, the crane control system horizontally mounts a gantry, a container that moves the crane itself by an operator's operation command from an operator cabin or an unmanned operation / remote operation (UMO / RMO). It is a system that performs a desired operation by appropriately controlling three types of electric motors such as a trolley which is a moving part and a hoist which is a container lifting part, and various driving devices (such as a rope tensioner and a spreader manipulator). That is, the crane control system has a unique form in which complex electric / mechanical control systems such as vibration suppression control of the load, spreader operation control, and rope tension compensator control are combined. In order to automate such a system, remote data measurement function that measures parameters and status of various electric / mechanical devices located at a long distance, functions that are in charge of sequential control according to the progress of the process, operation speed setting of the driving device, rope tension control It is required to develop unit element technology such as group control function that handles high speed loop control such as operation of various machinery and integrated technology of whole system.

However, in the conventional system developed for crane control and automation, the connection is performed using separate network protocols when connecting to the lower I / O devices 150, 160, 170 and the lower programmable logic controller (PLC) 140 shown in FIG. 1. You should. And mutual control between the control programming tool using the ladder diagram of the lower PLC (hereinafter referred to as LD) and the control programming tool using the functional block diagram of the upper control system (hereinafter referred to as FBD). Lack of relevance is a hassle for the user to learn both control programming languages. Otherwise, there is a difficulty that close cooperation between users of each programming language is necessary. In addition, in managing data required for system control and monitoring, a separate data management system is used. However, although the speed of the system is slightly faster, there is a disadvantage in that scalability and flexibility are lacking when additional devices are installed.

Therefore, the present invention has been created to solve the above problems, a complex unit such as a network interface (interface) technology, a user interface technology and a system control technology for the development of a crane control system, which is one of the automation system of the continuous process machinery We developed urea technology first, and then developed an Integrated Comunication and Control System (ICCS) with an integrated network that extended it to the entire system.

It is a first object of the present invention to provide a crane control system having an integrated network.

It is a second object of the present invention to provide a communication system for exchanging and managing data of an MMI system and a central control period among components constituting a crane control system having the integrated network.

A third object of the present invention is to provide a method for transmitting / receiving data of an MMI system and a central control period among components constituting the crane control system having the integrated network.

1 is a block diagram showing the configuration of a crane control system having an integrated network according to the present invention.

2 is a block diagram illustrating a structure of a data communication system between a central controller and an MMI system of a crane control system having an integrated network according to the present invention.

3 is a flowchart illustrating a data transmission / reception method of an MMI system and a central control period among components constituting a crane control system having an integrated network shown in FIGS. 1 and 2 according to the present invention.

4 illustrates a development environment of a control programming tool (Soft Logic Designer).

5 illustrates the structure of a Document & View of an SLD.

6 shows the overall structure of an SLD program.

7 shows an SFC editor.

8 shows the basic structure of an FBD block.

9 shows an FBD editor.

10 illustrates an example of a sequential function chart (SFC).

FIG. 11 illustrates a Petri net model for the SFC of FIG. 10.

In order to achieve the first object of the present invention, a crane control system having an integrated network includes an MMI system for inputting a control program, defining a structure of an entire system, and monitoring and storing various input / output signals and main data; A central controller that analyzes a control program input from the MMI system and takes charge of real-time control of the entire system, calculates input programs in a real-time event-driven manner, and manages various input / output data and main data; A direct input / output device connected to the central controller via a bus; A network driver connected to the central controller through the bus and driving and controlling a network; At least one remote input / output device connected to the network driver through the network and connected to various driving devices and sensors of the crane, and performing control commands of the central controller and loop control of the driving device; And one side is connected to the network driver through the network, the other side is preferably connected to a variety of motors, including a PLC to perform the sequential control of the motor.

In order to achieve the second object of the present invention, a communication system for exchanging and managing data of a central control period with an MMI system of a crane control system having the integrated network includes a control programming tool for creating and modifying a control program; An MMI communication server in charge of data transmission and reception with the central controller; A database for receiving and storing data of the central controller from the MMI communication server; A controller communication server in charge of data transmission and reception with the MMI system; A real time database storing data from the input / output device; A translator for compiling a program written in the control programming tool and converting the program into an executable file; An executor executing an executable file generated by the translator; And a data acquirer for importing data from the input / output device.

In order to achieve the third object of the present invention, among the components constituting the crane control system having the integrated network, a data transmission / reception method of the MMI system and the central control period is provided by the MMI system to the central controller. Transmitting header data including a valid key for inspection, type information defining types of data and a communication type, and information on the size of data to be actually transmitted; The central controller receiving the header data and checking validity of the data; And transmitting, by the central controller, actual data or requested data to the MMI system according to a communication type in the header data.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. 1 is a block diagram showing the configuration of a crane control system having an integrated network according to the present invention. The crane control system has a hierarchical structure of an MMI system, a central control system, and a lower I / O system.

The MMI system 100 inputs control programs (SFC, LD, ST, etc.) based on the IEC (International Electrotechnical Commission) 1131-3 standard, structural definition of the entire system, and monitoring various input / output signal and main data ( monitoring and storage. It is operated under IBM-PC compatible model and Korean MS-Windows95 environment in consideration of user's convenience and extensibility. The real-time central controller 110 using VME-Bus is interfaced with Ethernet (Ethernet (TCP / IP, UDP / IP)) to share data.

The central controller 110 is composed of a VME-Bus system, and analyzes various control programs input from the MMI system 100 to perform real-time control of the entire system, and input the programs in real-time event-driven. It operates in a manner, and performs a function of processing various input and output data and main data through the network driver 120 with the lower system (140,150, 160,170). The MMI system 100 communicates with Ethernet and uses a communication system having the same protocol with various sensors 175, remote input / output devices 150, 160, PLC 140, motor driver 145, and the like. Interfaced.

The network driver 120 is connected to the central controller 110 through the VME bus and serves to drive and control the lower network 180.

The lower I / O system is composed of a direct input / output device (130) connected directly to the VME bus and remote input / output devices (150, 160, 170) connected through the lower network. The direct input / output device 130 is connected to the central controller 110 through the VME bus and is directly controlled by the central controller 110. In addition, the remote input and output device (150, 160, 170) is connected to the network driver 120 through one of the lower network 180, the other is connected to various driving devices (155, 165) and sensors 175, the center The control command of the controller 110 and the loop control of the driving devices 155 and 165 are performed. The PLC 140 is connected to the network driver 120 through one of the networks 180 and the other to the various motors 145 to perform sequential control of the motor 145. .

The lower network 180 can be basically extended to 127 communication nodes according to the electrical specifications of RS-485, and the total length of the communication network can be connected up to 1500 meters using twisted pair lines. For communication, one parity bit and NRZ-toned 8-bit data may be synchronously transmitted, and a maximum of 246 data bytes may be transmitted in one frame. Data rates can vary from 3.6Kbps to 12Mbps.

2 is a block diagram showing the structure of a data communication system between the central controller 110 and the MMI system 100 of the crane control system with the integrated network according to the present invention, the control programming tool 200, It consists of MMI communication server 210, database 220, controller communication server 230, real-time database 241, translator (243), executor (245), and data acquisitor (247). .

The control programming tool 200 serves to create and modify a control program. The MMI communication server 210 is responsible for data transmission and reception with the central controller 110. The database 220 receives and stores the data of the central controller 110 from the MMI communication server 210. The controller communication server 230 is responsible for data transmission and reception with the MMI system 100. The real time database 241 stores data from the input / output devices 140, 150, 160, and 170. The translator 243 compiles the program created by the control programming tool 200 and converts the program into an executable file. An executor 245 executes an executable file generated by the translator 243. A data acquisitor 247 retrieves data from the input / output devices 140, 150, 160, and 170.

The operation of the present invention shown in FIG. 1 and FIG. 2 will be described.

Communication between the MMI system 100 based on an industrial PC and the central controller 110 based on the VME bus uses Ethernet, which is widely used as an industry standard. The communication protocol uses TCP / IP, which supports the physical layer, data link layer, network layer, and transport layer in the ISO / OSI 7-layer network structure. It is a representative interface for programming. V) The Transport Layer Interface (TLI) and Berkeley Unix (BSD UNIX) family of sockets exist.

Two-way communication is performed between the MMI system 100 and the central controller 110 shown in FIG. 2 using two socket ports. That is, the MMI communication server 210 is present in the MMI system 100 to always receive data transmitted from the central controller 110 through an application program interface (API) function call, and also to the central controller 110. The controller communication server 230 is present to receive data transmitted from the MMI system 100 to the API function call. Types of data transmitted from the MMI system 100 to the central controller 110 include configuration data related to the overall system configuration, characteristics and types of various input / output data, and input / output characteristic data representing actual addresses. And data transmitted to the central controller 110 from various applications. The data transmitted from the central controller 110 to the MMI system 100 includes data and alarm data generated at various input / output contacts for monitoring the system.

3 is a flowchart illustrating a data transmission / reception method between the MMI system 100 and the central controller 110 among components constituting the crane control system with the integrated network shown in FIGS. 1 and 2 according to the present invention. As illustrated, this is described as follows. In the present invention, since the type and size of data transmitted between the MMI system 100 and the central controller 110 vary, the header information is transmitted before the actual data is transmitted (step 300). It consists of a valid key, a type item defining the type of data and a communication type, and a yield indicating the size of the actual data to be transmitted next. Four types of communication data are defined. The first type is reserved for internal use such as communication check and execution of other tasks. The second type transmits only the communication header information because no actual data is required. The third type is a case of transmitting a header and actual data, and the fourth type is a case in which the MMI system 100 requests data necessary for the central controller 110. That is, an application program that transmits data to the central controller 110 or tries to obtain necessary data from the central controller 110 should send header information by filling the appropriate communication type into a type. The controller communication server 230 in the central controller 110 is a task that receives and interprets the data transmitted from the MMI system 100 and performs a corresponding process. In step 310, the real data may be received according to the four types of communication of the data, and the requested data may be delivered to the MMI system (step 320). The controller communication server 230 always transmits data transmitted from the MMI system 100. Because it must be ready to receive the header, the part responsible for interpreting the corresponding header should not be suspended, and if it is suspended, the processing unit must be created as a new task. Process data generated at the contacts of various input / output devices 145, 155, 165, and 175 may be used as important data for improving the process or identifying problems in the future by managing history data. In the present invention, the historical data is managed in consideration of this point. The historical data is used to monitor and control the status of the process. The monitoring of the process uses a separate monitoring tool. The historical data used in the monitoring tool extracts the historical data stored in the database 220 in the monitoring tool or from the MMI communication server 210 on the MMI system 100. It uses a method of obtaining historical data using OLE (Object Linking and Embedding). Management of the historical data uses a commercial database 220.

Commercial database functions used in the present invention include a report editing function for the historical data stored in the database 220, data processing functions such as extracting, modifying, and deleting the historical data and other application programs (for example, Microsoft's Excel). It also supports data linkage function and distributed database function that can be used in distributed environment. The distributed database function is a function that can be used even when the database server is in a remote system and a database client that accesses and uses the local server is in a local system. In addition, the present invention supports a standard call level interface (CLI) called ODBC (Open DataBase Connectivity) proposed by the microsystem company. In the present invention, the data is stored and extracted in the database 220 using the ODBC.

Types of data stored and managed in the database 220 according to the present invention include configuration data related to the overall system configuration, characteristics and types of various input / output data, and input / output characteristic data representing actual addresses and applications. Data stored in a database in a program, various input / output characteristic data, data stored in a database 220 in an application program, and process data generated at various input / output contacts. This data is stored in the form of records in a suitable database or extracted in record form. The process data generated at the input / output contacts transmits process data to the MMI system 100 by periodically calling a communication API function in a specific task of the central controller 110, and the MMI system 100 transmits the process data to the MMI communication server 210. The data is transmitted to the monitoring tool using OLE, and the process data is stored in the database 220 using ODBC. The stored process data may be managed through various tool report editing or data processing of the database 220, and the historical data may be read from the database 220 and used in an application program such as a soft logic designer (SLD).

4 is a diagram illustrating a development environment of a control programming tool (hereinafter, referred to as SLD). The SLD 200 includes five languages (Sequential Function Chart: SFC, Function Block) defined in IEC1131-3. Supports three types (SFC, FBD, ST): Diagram: FBD, Ladder Diagram: LD, Instruction List: IL, Structured Text: ST. The LD is not separately supported, but can be programmed like the LD using the FBD. In addition, the SLD editor supports multi-document editing (MDI) and can be conveniently used when writing or modifying a program. The SLD editor can be easily used even by a beginner by selecting a command by a graphic icon. The editor is supported separately as a child window for each programming language. That is, the SFC can be programmed using an editor using the characteristics of the SFC, and icons and menus corresponding to the corresponding languages can be used for each FBD and ST. FIG. 5 illustrates the structure of Document & View of the SLD, and MFC supports a special form called Document & View. It handles user interface View Class such as mouse input, screen picture, etc., and handles data processing and storage in Document Class. In other words, it classifies classes according to what they need to do, so it follows the concept of object-oriented programming. The SLD was also made using the document & view structure shown in FIG.

6 shows the overall structure of the SLD program. SFC, FBD, and ST editors can select, copy, and delete objects in addition to the basic drawing functions. However, grouping and ungrouping are not supported. You can undo up to one level.

FIG. 7 illustrates an SFC editor in which the SFC editor divides the entire screen into large blocks of nxn and draws SFC elements (BEGIN, STEP, TRANSITION, SINGLE BRANCH, DOUBLE BRANCH, JUMP BLOCK) in the block. . The reason for using the nxn array approach is that the SFC itself is in a fixed format, and this data structure can be more efficient in shaping code and implementing editors.

8 shows the basic structure of the FBD block, and FIG. 9 shows the FBD editor. The FBD editor has a free style in which a block can be placed at any position on the screen and a block style in which a block can be placed only at a predetermined position. Unlike the SFC, the FBD can be placed only at a predetermined position. However, the FBD is easy to implement, but it is not preferable from the viewpoint of user convenience. Therefore, considering the user's convenience, you should follow the free style. The FBD editor moves in 10-point increments rather than large blocks, like the intermediate SFC editor, which takes only two advantages. The connection line between the block (Figure 8) and the block (Figure 8) connects the input and output ports. If specified, it is generated automatically. One block consists of: Set the entire block to a size of 100 x 100 points. Based on this setting value, the overlapping of the blocks is determined. The number of inputs and outputs that a block can have is limited to three. When three or more inputs are required, they must be implemented in two or more blocks. The ST editor is a text editor written using the Windows Edit controls. Basic editor functions such as 'cut, paste, copy' are possible. Each data of the SFC and the FBD is created using a double linked list class provided by the MFC.

On the other hand, in order to describe the overall flow of the system, the SFC (Sfquential Function Chart) defined in the IEC1131-3 standard is used.Function Block Diagram (FBD) / Structured Text (STB) codes are used to configure each step in the SFC. Etc. Using such FBD / ST codes, control algorithms and application programs are described, and these codes are interpreted by the translator 243 to describe one source program. These codes are interpreted by the translator 243 and then executed by the real-time multiprocessing executor 245 using one source program.

The overall application configuration of the present invention consists of SFC (FIGS. 6 and 7) and FBD (FIGS. 8 and 9) / ST codes. In particular, it is SFC (FIG. 6, 7) which comprises the whole flow. The entire application program is configured in one SFC form, and this is made into a Petri Net model as shown in FIG. 10. Each step (No. S1 to S12 in Fig. 10) inside the SFC is tasked, and the overall flow process is performed by a scheduler having a higher priority, or by each task directly. Two ways of passing a token are supported. The PetriNet model eliminates the need for additional information about transitions in the selection / simultaneous branch (Figures 11: T1 through T11) (solved by the Petri Net model itself). There is no need to limit the nesting depth within. However, when the scheduler is used, the flow control is performed while scanning the transitions related to the ongoing tasks, thereby making the transition list required by the editor (FIG. 7) or the code generator (FIG. 7). An SFC is operated in a loop in the scan time, which is determined at the initial installation of the system, and when the flow time exceeds the scan time, the operation is stopped. Inform the user to modify the program. Apart from the total scan time, the user can configure the program by specifying an arbitrary loop.

10 shows an example of a flow control program using an SFC. This is represented by the Petri net model is shown in FIG. The first step of the Petri net model is always S1 (FIG. 11) and has an initial marking. Each of the steps (Fig. 10: S1 to S12, Fig. 11: S1 to S12) is made as a task in a real-time operating system environment, and for each transition (Fig. 11: T1 to T11) by the translator 243. Information about the in / out step is stored in the data structure, and the token path is determined using the information. In accordance with the IEC1131-3 standard, transition conditions are created only by "a single boolean expression," and the expression must not affect the values of other variables. Only a boolean is considered, thereby determining whether the flow will proceed. The ST codes in each step are stored in the corresponding memory block according to a predetermined format, and each task is itself an executor to perform a predetermined task along the memory block pointer. This single code / multitasking method handles much of the work in advance at the time of translation, reducing execution time and debugging the linked code in a task. This is easy, and it is easy to change the configuration of the memory block to the desired form from the outside. In addition, each function can be classified into several groups according to the number of input variables to form a data structure, thereby reducing unnecessary memory waste and increasing code execution time.

As described above, according to the present invention, the system developed in the present invention for process automation can be connected using a single integrated network protocol when connected via a network with lower systems such as a lower input / output device and a lower PLC. In addition, maintenance and management are convenient and costs can be reduced.

And since the control programming tool using SFC / FBD / ST of the upper control system is configured in accordance with the international standard IEC1131-3, it can be programmed in the same way as the control programming tool using LD (ladder diagram) of the lower PLC. have. Therefore, it is quite convenient because program authors and users only need to learn one control programming language.

In addition, it is easy to maintain and manage by using an integrated data management system in managing data required for system control and monitoring, and it is easy to add additional devices, so it is easy to expand and flexibility.

Claims (9)

An MMI system for inputting a control program, defining a structure of the entire system, and monitoring and storing various input / output signals and important data; A central controller that analyzes a control program input from the MMI system and takes charge of real-time control of the entire system, calculates input programs in a real-time event-driven manner, and manages various input / output data and main data; A direct input / output device connected to the central controller via a bus; A network driver connected to the central controller through the bus and driving and controlling a network; At least one remote input / output device connected to the network driver through the network and connected to various driving devices and sensors of the crane, and performing control commands of the central controller and loop control of the driving device; And One side is connected to the network driver through the network, the other side is connected to various motors, the crane control system having an integrated network, characterized in that it comprises a PLC for performing the sequential control of the motor. The method of claim 1, wherein the MMI system and the central controller Crane control system with integrated network, characterized in that connected via Ethernet. The method of claim 2, The communication protocol on the Ethernet crane control system having an integrated network, characterized in that the TCP / IP. The network of claim 1, wherein the network driver network It can be extended to 127 communication nodes according to the electrical specification of RS-485, and the communication line is a crane control system with an integrated network, characterized by a twisted pair wire. The bus of claim 1 wherein the bus is Crane control system with integrated network, characterized in that the bus is a bus. The method of claim 1, wherein the control program Crane control system with integrated network, characterized in that the control program based on the international standard IEC1131-3. In the data communication system between the central controller and the MMI system of the crane control system having the integrated network of claim 1, A control programming tool for creating and modifying a control program; An MMI communication server in charge of data transmission and reception with the central controller; A database for receiving and storing data of the central controller from the MMI communication server; A controller communication server in charge of data transmission and reception with the MMI system; A real time database storing data from the input / output device; A translator for compiling a program written in the control programming tool and converting the program into an executable file; An executor executing an executable file generated by the translator; And And a data acquirer for importing data from the input / output device. A data communication system of a crane control system having an integrated network. In the data communication method between the central controller and the MMI system of the crane control system having the integrated network of claim 1, Transmitting, by the MMI system, header data including a valid key for validating data, type information defining types of data and a communication type, and information on the size of data to be actually transmitted to the central controller; The central controller receiving the header data and checking validity of the data; And The central controller between the central controller and the MMI system of the crane control system having an integrated network, characterized in that it comprises the step of receiving the actual data or the requested data according to the communication type in the header data to the MMI system. Data communication method The method of claim 8, wherein the communication type of the header data Types reserved for internal use by the system, such as communication checks and execution of other tasks; A type of transmitting only communication header information because no actual data is required; Type of transmitting header and actual data; And Data communication method between the central controller and the MMI system of a crane control system having an integrated network, characterized in that the MMI system is one of a type for requesting data required for the central controller.