Design And Accomplishment Of The Machine Processing Control System Based On PLC

At present, the main control way in automatization field are relay control, microcomputer control and PLC control. Compared with the relay control system and the microcomputer control system, the PLC control system has a series of advantages, such as little work load of designing, installing, wiring and debugging, short cycle of development, high dependability, strong ability of anti-interference, low trouble rate, low requirement of working environment and convenient maintenance. So the PLC control system has become the first-selected control project of the domestic and international machine processing control objiect. Meanwhile, the relay control system has already been washed out on the machine processing control objiect early because it is inferior in technique performance and single in function. Compared with the PLC control system, the microcomputer control system is inferior in ability of anti-interference, high in requirement of working environment and long in designing and developing cycle of the control system. So its application has presented declining trend in the machine processing control objiect year by year. So designing and developing a good control system in technique performance have a very important meaning toward improving whole technique performance of the machine processing control objiect. The author chooses the PLC control system as the control project of the machine processing control objiect, which can play a good role in promoting the whole technical performance of the machine processing control objiect.In the design of machine processing control system based on PLC, the author has proposed and adopted the jump step method at first, thereby the number of total pushbuttons, which are needed by the PLC control system and applied to manual and autoloading control of each stand-alone, and the number of PLC input addresses which they engross are greatly reduced, and the developing expenses of the PLC control system are saved, and the installation and wiring work load of the PLC control system is less, besides, the convenience to the operation of the machine processing control objiect is also brought in the future. In addition, the author also develops a set of program for this system for the first time, which can make the machine processing control objiect return the origin automatically. Thereby the operation that makes the machine processing control objiect return the origin is greatly simplified. This paper also has provided the formula of calculating the numbers of total pushbuttons which are needed by the PLC control system and applied to manual and autoloading control of each stand-alone and the numbers of the PLC input addresses which are engrossed by thesepushbuttons, and the ones saved. The author has designed the machine processing control system based on PLC and provided the design and accomplishment program of software and hardware. This paper has made exposition to the design process of the motor drive electric control circuit and the fluid drive PLC control system in the machine processing control system based on PLC. In the design part of the motor drive electric control circuitry, the paper has explained the design process of main circuit and electric control circuit of motor, and provided the choice result of the electric elements of these two pieces of circuit. In the design part of the fluid drive PLC control system, the paper has explained the design process of the PLC I/O hookup, provided the choice result of the PLC and the PLC I/O elements, and has explained the design process of the PLC user program in detail, which includes the exposition to the design process of the public program, manual program of the stand-alone, autoloading program of the stand-alone, automatic/ autoloading program of whole machine, automatic return the origin program of whole machine, signal showing and trouble alarm program, and provide the trapezium drawing of all programs mentioned above .At last, according to the theoretical design, machine processing control system based on PLC is processed c...