X-ray Diffractometer Control System Design

With the development of science and technology,X-ray diffractometers have played an increasingly important role in many fields of science in China,especially in the fields of materials science,medicine,pharmacy,and metallurgy.It made higher demands on the performance of X-ray diffractometer.The imported X-ray diffractometer has high precision and advanced technology,but it's price is also high.China is relatively backward in the research of X-ray diffractometers,In order to promote the development of domestic X-ray diffractometers and extend the application of X-ray diffractometer in scientific research,it is urgent to develop a domestic high-precision X-ray diffractometer with independent intellectual property rights.This paper analyzes the background of X-ray diffractometer and learns more about the working principle of X-ray diffractometer,by analyzing the requirements document,this paper put forward a design scheme of the diffractometer control system based on ARM and CPLD.Based on the research and analysis,this paper implements and validates the scheme.In the specific work,this article has completed the design of the hardware schematic diagram of the control system and the design of the printed circuit board.The system uses STM32F4 chip as the main control chip,it performs the main task of diffractometer control and completes the counting of pulses with the cooperation of the CPLD.In addition,this system uses the communication mode of CAN bus to realize the communication between the control board and the accessories.It proved that the communication is reliable after test and this paper realized the “real-time” detection of attachment types through software design.A simple and high-efficiency motor control algorithm is designed so that the goniometer can be operated according to uniform speed,acceleration,constant speed,and deceleration.On this basis,an effective reset strategy can be formulated to significantly reduce the error caused by resetting the goniometer.At the end of the paper,it does a test of the diffractometer controller board for functionality and stability in the actual work environment,the test results meet the design requirements.furthermore,using corundum as a test sample,it was scanned using this system,the test results agree well with the standard diffraction pattern,which proves that the system can meet the design requirements and achieve all expected functions.