Design Of Motion Control System For Current Sensor Calibration Equipment

With the rapid development of human society and the increasing tension of land resources,the exploitation of marine resources has been regarded as an important driving force for the development of social economy.China has clearly put forward the strategy of "marine power",which is of great significance to the modernization of our country.In the development of the ocean,the ocean observation technology is the basic means to carry out the marine science research.For the problem of weak upwelling measurement,our research group has developed a new type of current sensor.In order to realize the calibration of the sensor,the current sensor calibration device is designed based on the principle of relative motion transformation,and the motion control system is designed in this paper.Firstly,we determine the functional requirements and performance indexes by analyzing the calibration requirement of ocean current sensor.The single axis feed system is put in the X,Y,Z three axis direction,and it can achieve the horizontal and ascending movement of the calibration device in the way of “servo motor + ball screw + linear guide rail transmission”.The DSP chip TMS320F28335 is selected as the core processor of the control system,and the D/A converter,pulse signal processing and serial communication are designed form the DSP motion controller.According to the actual requirements of calibration device of steady speed and positioning accuracy,we use the speed control mode of the servo motor as the inner loop.Simultaneously,we also use the speed outer loop and the position outer loop to realize the full closed loop control in the process of single axis movement.Among them,the speed outer loop is controlled by the classical PID,and the position outer loop is controlled by SMC.Under the CCS integrated development environment provided by TI company,the DSP program code is written,and the upper monitor of the control system is realized based on the Labview software platform.Finally,the performance test of the system is carried out,which includes the function detection of the hardware circuit,the running test of the control system,the experiment of the speed accuracy and the positioning precision experiment.Through the analysis of the experimental results,it is proved that the motion control system can meet the performance requirements.