Design Of Combinable Multi-modal Process Tomography System

Process tomography has the characteristics of non-intrusion and visualization,and can detect the phase distribution parameters of complex flow.Process tomography can be applied to fields such as multiphase flow and medicine.Common tomographic modalities include electrical,ultrasonic,and ray,each of which is sensitive to specific physical parameters of the process being measured.Electrical capacitance tomography,electrical resistance tomography and ultrasonic tomography are the process tomography techniques based on different physical principles.The applicable range and imaging characteristics of the three technologies have their own advantages.Ultrasonic modality and electrical modality are complementary in their measured parameters and sensitive field distribution.Through the integration of different modal measurement data,multi-modal process tomography has great potential in multiphase flow,medical online visualization and parameter measurement.Currently,there is no tomography system that can integrate ECT,ERT,and UT modes for multimodal tomography systems.The current multi-modal systems have the disadvantages that the modal configuration is not flexible enough,the interfaces are not uniform,and they cannot be freely combined.In order to solve this problem,this paper proposes a combined multi-modal tomography system based on CPCI.The main research work is as follows:(1)A combined multi-modal tomography system is designed.A multi-modal communication interface based on CPCI is designed.A unified multi-modal data acquisition board hardware standard.A unified hardware standard for multi-modal data acquisition boards is proposed.Each modal tomography module based on multi-modal system is designed.According to the difference of physical parameters of the measured object,the appropriate modal measurement board can be selected to access the combined multi-modal system to realize the free combination of different measurement modals.(2)A multi-modal system control line based on the CPCI hardware standard is designed.Designed communication logic between multi-mode boards.FPGA-based multi-modal master module and multi-modal controlled module are designed.A method for processing asynchronous clock domain signals based on FPGA is proposed.Improved the existing single-mode system in the laboratory,making it a subsystem of a combined multi-modal tomography system.(3)The online data acquisition experiment of the system was completed,and the static imaging experiment of the system was completed with nylon simulated multiphase flow.The results show that the combined multi-modal system can achieve multi-modal synchronization work with high data real-time and multi-modal time synchronization.