Research On Key Technologies Of FDM Additives Based On Motion Control

Desktop level FDM additive manufacturing technology plays an important role in additive manufacturing industry because of its low price,simple operation,short commodity development cycle and simple maintenance in the later stage.The desktop FDM additive manufacturing system is driven by stepper motor.However,Commonly used stepper motor motion control algorithms have problems such as unsmooth joints of speed curves,sudden changes in acceleration and jerk curves.At the same time,it is necessary to consider the computing power of the microcontroller,which limits the flexible control of the stepper motor and affects the model forming effect of desktop FDM additive manufacturing.In addition,G-code interpreter and temperature control of desktop-level FDM additive manufacturing system have important influence on model shaping.Based on the above analysis,the key technologies of FDM additive system are designed in this paper.The main research work is as follows:First of all,in view of the shortcomings of the traditional used stepper motor acceleration and deceleration curve algorithms,as well as the requirements of FDM system,an acceleration and deceleration algorithm with continuous jump curve,continuous guiding acceleration,speed and displacement curves and smooth curve connection was designed.The acceleration and deceleration algorithm is combined with Sp TA algorithm and Bresenha algorithm to form a motion control fusion algorithm,which realizes multi-axis linkage of desktop level FDM additive manufacturing system.Secondly,in order to realize efficient recognition of the G-code in desktop level FDM additive manufacturing system,a G-code interpreter is designed.The interpreter realizes the functions of G-code preprocessing,error detection analysis,data structuring,and sending key data to the lower computer.Finally,a feed-forward fuzzy PID temperature control algorithm is designed to solve the problems of excessive overshoot and long adjustment time when the traditional temperature control algorithm adjusts the temperature.The temperature response has no overshoot and the adjustment time is short,so that the temperature fluctuation range of the nozzle is small,and the extrusion speed of the consumable is matched with the movement speed of the nozzle.In order to test the forming effect of the model,a prototype of desktop FDM additive manufacturing system was built.The test results show that the designed motion control fusion algorithm improves the motion control performance of the stepper motor.When using the feed-forward fuzzy PID temperature control algorithm to control the temperature,the relative error of the printed three-dimensional model is less than 1%.It shows that the key technologies designed in this paper enable the desktop FDM additive manufacturing system to have the advantages of good shaping ability and stable operation and meet the printing requirements.