A deformation measurement method of interframe displacement was proposed in this paper. By online monitoring the shape dimensions of both the deformation zone and its adjacent zone by machine vision, the initial and t...A deformation measurement method of interframe displacement was proposed in this paper. By online monitoring the shape dimensions of both the deformation zone and its adjacent zone by machine vision, the initial and terminative positions of deformation were dynamically identified during dieless drawing, and the global monitoring and online closed-loop control of the deformation zone were achieved. The dieless drawing process was systematically carried out on NiTi shape memory alloy wires. It is shown that the deformation measurement method of interframe displacement can track the axial displacement of the wires, but this cannot be achieved by traditional machine vision. The initial and terminative positions of deformation can be accurately identified by this method. The proposed rectifying control technology can effectively decrease the wire diameter fluctuation during dieless drawing, that is, the standard deviation of the wire diameter fluctuation could be decreased from 0.30 to 0.08 mm after three passes of dieless drawing, indicating that the control system has a good rectifying ability.展开更多
基金financially supported by the National Basic Research Priorities Program of China (No.2011CB606300)the National Natural Science Foundation of China (Nos.50634010 and 50674008)+1 种基金the Program for New Century Excellent Talents in Chinese Universities(No.NCET-06-0083)the Universities Fundamental Research Foundation of the Ministry of Education, China (No.FRF-TP-10-002B)
文摘A deformation measurement method of interframe displacement was proposed in this paper. By online monitoring the shape dimensions of both the deformation zone and its adjacent zone by machine vision, the initial and terminative positions of deformation were dynamically identified during dieless drawing, and the global monitoring and online closed-loop control of the deformation zone were achieved. The dieless drawing process was systematically carried out on NiTi shape memory alloy wires. It is shown that the deformation measurement method of interframe displacement can track the axial displacement of the wires, but this cannot be achieved by traditional machine vision. The initial and terminative positions of deformation can be accurately identified by this method. The proposed rectifying control technology can effectively decrease the wire diameter fluctuation during dieless drawing, that is, the standard deviation of the wire diameter fluctuation could be decreased from 0.30 to 0.08 mm after three passes of dieless drawing, indicating that the control system has a good rectifying ability.
