Research And Design Of Control System And Algorithm For Crystal-bar Orientated And Fixed Machine

Orientating and Fixing are two important steps during cutting and machining process of crystal-bar.In the traditional manufacturing process,orientating and fixing are two indepen-dent steps.According to Bragg equation,X-ray goniometer detects and marks the location of atomic surface inside the crystal-bar with technology of X-ray diffraction.Crystal-bar fixed machine makes the location of atomic surface inside the crystal-bar to parallel with target cut-ting surface and meanwhile vertical with bonding surface by rotating and swinging in accord-ing to the mark,and then fixs crystal-bar with glue to prepare for next cutting process.It is such a low level of automation that to design and develop a full-automatic orientated and fixed machine for crystal-bar has a significant meaning to improve producing efficiency and to promote development of the industry.The thesis has designed a control system for crystal-bar orientated and fixed machine based on FPGA platform to achieve the control for multiple motors and accurate measurement of the intensity of X-ray diffraction.From the aspect of hardware,the framework is estab-lished with a core of FPGA and support with current detection chip,ADC,photoelectric coupler chip and driving amplifier chip to achieve measurement of motor winding currents,feedback voltage of X-ray detection sensor and encoder signal and the control for motors and magnetic valve.With a core of IPM,the power circuit establishes a three-phase inverter con-trol circuit to drive the motors.From the aspect of software,based on FPGA,an embedded Nios ? soft core processor is used to achieve the function of full-automatic orientated and fixed machine with IP core of different desired modules.At the same time,the thesis designs HMI to monitor and control the system.In the thesis,it is important and difficult to design a proper controller to fulfill three closed-loop servo control system under the circumstance of varying load with PMSM.Finally,according to the design idea of fully closed-loop control and the method of vector control,the thesis used PI controller in current loop and position loop and designed internal model con-troller in velocity loop which is influenced directly by varying load.Simulation experiments have shown that the internal model controller has a good robustness which is adept at an-ti-interference.So it is fit to be used in this system which has a feature of varying load.The thesis's main work includes:the hardware design of control system for crystal-bar orientated and fixed Machine,the software design of control system for crystal-bar orientated and fixed Machine,the control algorithm research of servo system under the circumstance of varying load.