Design Of Hydraulic Experiment Platform Based On Programmable Logic Controller (PLC)

With the development of modern hydraulic technology, the traditional hydraulic experiment platform for teaching can not meet the demand of hydraulic technology, and it is not conducive to improve the students’ interest. Modern platform, the PLC controlled hydraulic experiment platform, has advantages on removablity, detachablity, free-combining and visiblity on experiment process. And its smaller size, as a result of integration, takes more advantages on operating, overhauling and processing. Modern hydraulic experiment platform consists of PLC for guest computer and PC with configuration software for host computer. Visibility of experiment process can be realized in this system, and it helps to arouse the students’ enthusiasm and creativity.This paper designed PLC controller of hydraulic experiment platform in such context. Firstly, the paper discussed the necessity to design PLC controlled platform, designated the deficiency of driving system by analyzing the structure and features of traditional platforms. Secondly, the basic thinking about designing PLC controller was put forward. Then, PLC was described in detail in its control problem. According to the demands of hydraulic system and electrical control system on experiment platform, determining the PLC input and output points, establishing the allocation table of input and output address, giving the specific real linking graph, simulation linking graph, and PLC-controlled electrical principle diagram, PLC programming, which was composed of four sequential action loops controlled separately by sequence valve, pressure switch, motion valve and position switch, could be achieved. In the end, designing procedure of PLC controlled hydraulic experiment platform was described in details. The system was programmed by the two stepper instructions, STL and RET. It designed the PLC function diagram which contained feeding, clamping and machining. Then The PLC instruction statement could be programmed according to the PLC ladder diagram converted from function diagram. Meantime, it designed the system’s simulation linking diagram for taking a better understanding on the sequence of feeding, clamping and machining.