Research On Synchronous Position Servo Control For Dual-Axis Of Industrial CT

As one of the best non-destructive testing technology, Industrial ComputedTomography (CT) technology has been gradually applied in many fields, such asindustrial manufacture, aerospace field, safety monitoring. With the range of applicationbroadening, the requirements for better imaging quality and faster scanning speed areput forward. The position synchronization movement of the ray source axis and thedetector axis is one of a main part of industrial CT scanning motion, and the runningspeed, positioning accuracy, tracking accuracy and precision of synchronizationperformance of the movement are very important for industrial CT to get accurate andeffective scanning data. The purpose of this paper is to improve the performance of theposition synchronization movement of the ray source axis and the detector axis. Theresearch is finished concretely as follows.Firstly, the characteristics of synchronous movement and its load in typicalindustrial CT system were researched. Based on the research on mathematical modeland vector control of PMSM (Permanent Magnet Synchronous Motor), the controlmodel of Industrial CT single-axis position servo system was built.Based on the PID control rule, the setting methods for current loop, speed loop andposition loop in position servo system were researched. A position feed-forwardcontroller and a speed feed-forward controller were designed to improve the system’stracing performance, a disturbance observer was designed to improve the robustness ofthe system. The simulation results showed that the positioning precision and trackingperformance of the single-axis position servo system was improved effectively.Several kinds of synchronization control strategy such as concurrent control,master-slave control and cross-coupling control were researched. Based on thecross-coupling control strategy, a Dual-Axis position servo system was built, and thefuzzy PID control method was used to compensate the position error of the dual-axis.From the comparative simulation results, The compensation performance of fuzzy PIDis better than common PID.Finally, took a certain kind of industrial CT as the research object, the dual-axisposition servo control system model of ray source axis and the detector axis was builtbased on fuzzy PID cross-coupling controller. The Matlab/Simulink simulation resultsshowed that the system had satisfactory position command tracking performance, synchronization performance and robust performance, could provide a feasiblereference scheme for biaxial synchronous motion control of industrial CT.