Modeling And Control Of Tension For Reciprocating Single Diamond Wire Saw Cutting Machine

With outstanding characteristics, the SiC mono-crystal has become the core material for the 3rd-generation semiconductors. However, the high hardness, good abrasive resistance and stable chemical properties make it difficult to be manufactured. Cutting technology plays an important role in the process of machining SiC ingot into wafer, because its cutting quality has a great influence on the subsequent processing technology. The experimental results show that wire vibration in Slicing process for the fixed-diamond wire saw has significant effect on thecutting quality, and surface quality can be improved by decreasing wire vibration with effective tension control, which is a key factor affecting wire vibration.Based on the dynamic characteristics of wire feed system in the single reciprocating diamond wire cutting machine, the mechanical model of tension for the wire feed system was developed. The effects of different parameters, such as the cutting speed, the friction coefficient and rotational inertia of guide roller on wire tension were as follows. There is a liner relationship between the speed and the change of tension, wire tension increases with wire moving velocity, tension fluctuation range in the process of start. re versing and braking of wire feed system was mainly influenced by the friction coefficient and rotational inertia of guide roller, which are the higher and the tension fluctuation range is bigger.A wire tension controller based on pressure sensor and screw drive was developed. The design of the mechanical structure of the controller, the selection of the main components and the design of the controller hardware system have been completed. Based on the TMS320F28335 DSP chip, the real-time acquisition of tension, the control of the speed of motor and the communication function of between the controller and PC have been realized .With the utilization of LabVIEW graphical programming software, the human-computer interaction interface of tension controller was developed. As a result, many functions such as the set of control parameters of tension controller, the real-time display and recording can be achieved. Using the proposed Fuzzy-PID controller used in tension control of wire feed system,the tension under various feed speed can be effectively controlled compared to the traditional PID controller.The experiment and the test of software and hardware were performed, which verified the effectiveness of wire tension controller. The experimental results show that in the open control,tension will be dramatically increased or decreased when reversing, and the tension variation is characterized with segmentation, on the other hand, sudden tension change or tension fluctuation at reversing restrained in closed-loop control, and the tension variation range with proposed tension controller is from 3.6N to 0.4N.