Motion Optimization Method Of 3D Printer Based On Internal Model Control

As a key branch of emerging manufacturing methods,3D printing technology has significant advantages such as strong manufacturing capacity,low processing costs,and high material utilization compared with traditional processing technologies.Among them,Fused Deposition Modeling(FDM)has become the most common application form in the 3D printing industry due to its simple structure and low price.However,the FDM printers are often working in a state of reciprocating motion with low load,high speed,and frequently switching directions.It is very easy to cause the losing timing of motor,and produce harmful vibrations,resulting in poor printer molding quality,reduced work efficiency.It may even cause the loosening,wear and fatigue failure of various assembly parts,and reduce the working life of the machine.Therefore,optimizing the printer motion control based on the concept of low cost,effectively improving the printing efficiency and molding quality has important scientific significance and engineering value.From the perspective of effectively restrain the vibration,this paper deeply analyzes the mechanical structure and transmission characteristics of the printer,Based on that,using the method of independence and integration,combining with the Lagrange equation method,the influence of the deformation of the synchronous belt and the mechanical characteristics of the motor rotor on the transmission is studied,the dynamic model of printing nozzle and printing platform is constructed.Considering the influence of model uncertainty on control accuracy and efficiency,an internal model control algorithm with low sensitivity to model mismatch and the ability to suppress uncertain factors such as disturbance is introduced.An internal model loop which can be equivalent to the superposition effect of external disturbance and input feedforward is proposed to be added into the negative feedback channel of internal model PI control,which could be equivalent to the superposition effect of external disturbance and input feedforward.So as to realize the optimization of 3D printer motion control under the premise of low cost.The control algorithm is simulated and analyzed through numerical examples.The results show that the use of the compound control composed of the synergy of dual internal molds can achieve better target trajectory tracking performance and disturbance suppression effect,thereby improving control flexibility,work efficiency and molding quality.Based on the above algorithm,a control framework for printer motion optimization is constructed,and the dSPACE software and hardware system is used to control the printer motion in real time.Comparing the molding quality and printing efficiency of printed parts before and after using different control schemes under different acceleration limits,the experimental results show that the internal model improvement algorithm proposed in this paper can obviously overcome the problems caused by vibration interference and model mismatch to motion control.The target trajectory tracking performance can meet the system's requirements for robust stability and dynamic response speed,verifying that the dual internal model control algorithm can effectively improve the printing efficiency and molding accuracy,and has significant advantages in the motion optimization effect of the 3D printer.In addition,the dynamic modeling process in this article provides a basis for the further development and improvement of the printer.It also has a certain reference value to the design of motion controller and parameter setting method of step drive system.