Design And Research Of PLC-based Micro-CT Antomatic Scanning System

Computerized Tomography, called CT for short, is a technology to reconstruct two-dimensional image of the object's particular section, according to the projection, and then build three-dimensional model of the object. Micro-CT, using micro-focus X-ray tube, having micron resolution, can reproduce the three-dimensional form of the object's internal structure and material holographically and non-destructively. Micro-CT has been widely used in life science research, pharmaceutical research, materials research and product testing etc. This paper developed a PLC-based micro-CT automatic scanning System, on the basis of full research on micro-CT and mechatronics, to meet the need in bio-medical experiments.Firstly, the development and status of the micro-CT technology and equipment application was studied. And a project of developing a micro-CT automatic scanning systems was proposed, according to the need in bio-medical experiments. Then the feasibility of the project was verified,on the basis of the study about the international mechatronics technology particularly CNC and PLC control technology.Secondly, the general scheme of the micro-CT automatic scanning systems was studied. The mechanical motion scheme of this system was designed. Also a secondary control system was identified, which uses PLC as the control center, PC as the superior controller, and servo motor and scanning equipment as the execution unit.Then, according to the general scheme, the mechanical structure of the system was studied, and the mechanical structure of the various components was specificly designed to achieve the design requirements about mechanical structure and motion function.Finally, according to the general scheme, control structure was studied. The hardware and software of the control system was designed specificly, including the selection of the electrical components and circuit connections. Mechanical motion control function was achieved with the serial communication technology. And micro-CT scanning control function was realized through the Windows message-driven mechanism.Based on the above study, the design of Micro-CT automatic scanning system was completed. This system has realized the automation of CT scanning process, with all design requirements met. It has been used in bio-medical experiments, and the efficiency of the experimental is greatly improved.