The integrated course design of programmable controller control system design and debugging is a comprehensive applied course implemented according to the requirements of enterprises for high-skilled talents and the actual requirements of enterprises’production.The course takes the enterprise practical project as the main line, with high and new technology as the support, and the brand-new integrated teaching mode as the carrier, trains high-quality skilled technical talents, and promotes the reform and development of technical education and vocational training teaching.This paper expounds the overall design of the course of design and debugging of programmable controller control system, the detailed steps of the course implementation of design and debugging of programmable controller control system, and the project of the course implementation of design and debugging of programmable controller system.In modern advanced manufacturing industry, automation control has been realized in modern production, which not only adapts to the development of social economy, reduces the number of operating workers rapidly, solves the shortage of labor encountered in the current industrial economic development of our country, but also greatly improves product quality and production efficiency, and enhances the competitiveness of our industry.In order to realize automatic production, modern industry has adopted programmable logic controller to control the system, eliminating the relay control system mainly consisting of contactors, relays and other electrical components. The disadvantages of the relay control system, such as huge volume, complex circuit, poor flexibility, high cost, poor reliability and maintenance difficulties, can not be overcome and can not adapt to the rapid development of contemporary industrial students. Production demand.The programmable control system with the programmable controller as the core integrates three electronics (electronic control, electrometer, telex) and has the advantages of high automation integration, flexible technology transformation, stable and reliable operation, easy expansion, etc. Therefore, the programmable controller has become one of the three technical pillars of modern industrial automation (PLC, robot, CAD/CAM), and has become one of the main technologies of industrial 4.0.To transform China from a big manufacturing country to a manufacturing power, it is essential to master advanced modern industrial automation technology.In modern production, programmable controller control technology has become the basic requirement of electrical technicians and engineering students, but in actual teaching, it is found that few students can master and use programmable controller control technology skillfully, which requires a new integrated teaching to promote students to master this technology skillfully.Programmable Controller Control System Design and Debugging Integration Course combines the practical engineering of enterprises, takes the working process of engineers and technicians to complete the whole project as the teaching template, takes the method of training engineers and technicians to train students, cultivates students’learning ability, thinking ability, practical ability, team cooperation ability, etc., with the main purpose of improving students’ comprehensive ability, and promotes learning. Students firmly grasp the advanced industrial automation technology, and can use the technical skills learned to solve the problems encountered in the realization of work.In the course of integrated design and debugging of programmable controller control system, besides teaching advanced industrial automation technology to students, teachers are more important to guide students how to correctly analyze, solve and summarize problems, so as to lay a solid foundation for students to become high-skilled talents in the future.Teachers engaged in this course should have rich enterprise experience and strong teaching ability, which is also a promotion for teachers.Programmable Controller Control System Design and Debugging Course combines several courses: CAD Drawing (Drawing Electrical Control Chart), Tool Use and Machining (Manufacturing of Electric Box), Electric Drive (Design and Manufacturing of Control Circuit), Electrical Basis (Selection of Components), Sensor Technology (Selection and Use of Sensors), Writing (Writing Technical Documents), PLC Technology (Design of Control System), Frequency Conversion. Device technology (control system design), touch screen technology (control system design), configuration technology (control system design), etc., is a comprehensive application of multi-disciplines, is a real battle before graduation of students.Programmable controller control system design and debugging course teaching is mainly student-oriented, teacher-assisted; students independently complete, teacher monitoring and guidance; close to the actual production of enterprises, training skills and technology, training technicians, a graduation can start.Programmable controller control system design and debugging course real reproduction technology project implementation process, from the process requirements, process design, component selection, cabinet production, programming, installation equipment debugging, technical data collation, equipment, technical data, acceptance.Through the study of this course, students can fully experience the joy and pressure of being an industrial controller, and master the process and working methods of technological transformation of enterprises.Programmable Controller Control System Design and Debugging Course is implemented by group learning.
The project is implemented continuously with 4 people in each group and completed by team cooperation.According to the process flow, process requirements and objectives of the project provided by customers, the mechanical actions involved in each process step are carefully analyzed, as well as the motor, hydraulic and pneumatic operation modes required to complete the mechanical actions. The control scheme is put forward, the control mode is determined, and the project design task sheet is written. When the process requirements are questioned, the customer should be contacted and communicated in time. Guarantee the correctness of the design scheme.
Through this step, students’abilities of analyzing, finding and solving problems and communicating with others are trained. Students are also allowed to summarize the electrical control technology they have learned. In addition, students are also allowed to learn the advanced technology being used in enterprises. Students can also master the design concept of electrical control system.Based on the design scheme of project control system, the models and brands of input devices such as switches, buttons and sensors needed for control, and output devices such as indicator lights and intermediate relays are selected. According to the types and quantities of input signals, the object of control is selected, and the capacity, I/O points and special modules of programmable controller are determined. Content: According to the power requirements, by calculating the magnitude of the torque, and according to the power operation mode, select motor types such as servo motor, variable frequency motor, ordinary motor, and select the capacity and type of motor.In this link, teachers teach students the basic knowledge of budgeting, type selection and calculating moment. Students can carry out engineering practice by means of network investigation and market consultation of electrical equipment, understand the type, quality and price of electrical equipment, master the necessary knowledge of how to make budget, how to select type and how to calculate moment for engineering and technical personnel, and support themselves. Have the design ability to lay the foundation.According to the design scheme of project control system and the selection of equipment, the electrical circuit of the project is designed.First, the I/O point of the programmable controller is allocated, the I/O distribution table is drawn, the peripheral circuit design is designed with the core of the programmable controller, and the circuit diagram is changed into electrical schematic diagram and wiring diagram.In this part, students should not only be able to understand the electrical circuit diagram, but also have a deep understanding of the characteristics and general rules of the electrical circuit diagram, as well as the method of electrical drawing and the identification and drawing of electrical components, learn to use CAD to design the electrical circuit diagram, in addition, they can also design the electrical equipment layout and wiring diagram.According to the project electrical device layout and wiring diagram, the production of control cabinet and operating table.In this process, teachers teach the experience and methods of mechanical processing and electrical hardware assembly, and the assembly process requirements of the mechanical and electrical integration project of the World Skills Competition, so that students can broaden their horizons, understand international skills standards and master them.Through this process of training, students should be able to design and construct electrical hardware, master the methods of mechanical processing, such as the use of mechanical tools, sheet metal processing, machine tool use, and have the ability of mechanical assembly; according to the wiring diagram, according to the world technical assembly process standards, on-site wiring, including the use of wires, thermostatic element cold-pressed terminals, wiring connection, and so on.
Check the correctness of the line connection in detail.According to the design scheme of project control system, program design is carried out, and suitable programming methods are selected according to the process of the project, such as using experience programming method or step-by-step programming method.The main line of the program is to meet the requirements of system control. The program is to realize the control function of each part or each sub task, and gradually improve the overall function of the system.
Combining with the mechatronics project of the World Skills Competition, the teacher explains the contents that should be paid attention to in the programming of enterprise engineering projects: the design of safety protection measures, the design of man-machine dialogue, the design of program mutual protection, the optimization design and so on.Through the preparation of specific engineering projects, students have the experience of practical engineering programming, and learning is no longer out of touch with them. Students learn engineering programming skills and grasp the engineering programming skills. They will not feel the engineering program design is unpredictable, and establish confidence in their future technical work.After the project programming is completed, the simulation debugging should be carried out to simulate the on-site operation process of the project, to provide operation signals for the program operation, to observe whether the results of the program operation meet the project requirements, and to ensure the correctness of the program.Students master two methods of simulation debugging through simulation debugging: hardware simulation method and software simulation method.Students can use buttons, signal generators and other hardware devices to simulate the production of field signals, and connect these signals to the input of the PLC system, operate the input signal to observe whether the output signal is correct, to detect the correctness of the program.Students can also write a simulation program to simulate and provide on-site signals. The correctness of the program can be judged by the monitoring function of the software.After the program simulation debugging is completed, the program is applied to the project.The debugging process should be carried out step by step, from PLC connecting only input equipment, then output equipment, and then to actual load.If it does not meet the design requirements, the hardware or program shall be adjusted accordingly.In addition, according to the implementation of the program and mechanical optimization, under the premise of safety and reliability, as far as possible to improve the efficiency of equipment and reduce energy consumption.After all debugging is completed, it will be delivered for trial operation.After a period of operation, if the work is normal and the program does not need to be modified, save the program to prevent loss.In debugging, students will find many problems.
Teachers only play a guiding role in cultivating students’ability to solve problems independently.After project design, installation, programming and debugging, technical documents should be compiled and sorted out, and the operation instructions, technical instructions, electrical circuit diagrams, wiring diagrams, detailed lists of electrical components, and PLC programs should be handed to customers.Teachers should teach the skills of writing technical documents in this link.Through this link, students not only master the writing of technical documents, but also improve their writing ability, laying the foundation for their future writing papers.Taking the design of project-annealing furnace transmission roller PLC control system as an example.The transmission roller is one of the most common and widely used equipment in the production enterprise. It is used to transfer materials, save manpower and improve production efficiency. The transmission system can implement simple control or complex full automatic control.This project can set the degree of difficulty according to students’mastery of knowledge, but it can be applied in production to enable students to master production technology and electrical equipment design skills.
Basic design requirements.The main control circuit of annealing furnace material conveying roller is composed of a Y series three-phase AC asynchronous motor with 1.5kW and its control elements.The cooperation and interlock between the lifting of furnace door and the operation of roller must meet the technological requirements.The control system should be able to meet the requirements of fully automatic circular processing and manual adjustment of the process.The conveying roller enters the annealing furnace according to the sequence of one material. After satisfying certain conditions, the material is conveyed out of the annealing furnace and the conveying task is completed once.Then the second job.The main circuit of the system has a power supply voltage of 380V, a control circuit of 220V, a PLC control circuit of 24V and a direct current of 24V.Attention should be paid to safety measures design, hardware interlocking design, voltage level design and PLC program interlocking design when carrying out system design.。Implementation of multi-stage frequency conversion speed control in different areas.Implement automatic control according to furnace temperature.Man-machine dialogue is implemented with touch screen.Computer monitoring.Design technical parameters.Design content.According to the operation process and control process of material conveying roller of annealing furnace, the function chart is designed.
According to the design requirements, the control scheme is selected.Select the type of PLC, design the hardware system of PLC, draw the corresponding PLC wiring diagram.Select the components of PLC control system, and list the detailed list of components.Design of control cabinet and peripheral components.The ladder diagram of PLC control is designed.Write design instructions.Required components.Required tools.Programmable Controller Control System Design and Debugging Integration Course is a course for students to complete engineering examples by themselves. This course not only improves students’interest in learning, but also improves students’ electrical automation technology and skills. It also enables students to deeply understand and master the essence of the mechatronics project of the World Skills Competition: safety, reliability, efficiency, saving, and more. What is important is that students learn how to do technical work in the future.