Research on trajectory tracking of motion control system of wood-plastic material 3DP printer
Wood additive manufacturing technology can help reduce the cost of 3D printed products and reduce carbon footprint.Aiming at addressing the problem that CoreXY mechanism has poor printing accuracy when performing open-loop control due to the large load of X-axis in the motion control system of wood-plastic 3DP printer,the intelli-gent trajectory tracking algorithm of model predictive control(MPC)of 3DP printer was investigated to improve printing accuracy and printing speed.The motion control system of wood-plastic material 3DP printer was designed based on three-dimensional printing(3DP)molding process and transmission characteristics of the CoreXY mecha-nism,and an MPC trajectory tracking strategy adapted to 3DP printer was proposed.The print trajectory of an appro-ximate circular slice under the cartesian coordinate system was used as the reference trajectory,the prediction model and loss function of the closed-loop system of A and B motors of CoreXY mechanism was established.Then the multi-constraint optimal control problem of printing speed and precision was transformed into a quadratic function with con-straints,which can be solved using the model predictive control theory.By comparing the errors between the reference trajectory and the actual printing trajectory and comparing the effectiveness of the MPC and PID controls,the influence of different printing speeds on the trajectory tracking effect was studied.The simulation results were analyzed and calculated.It was concluded that the reference trajectory could be tracked accurately at the spray glue sites of 3DP printers within the range of 80-400 mm/s.The maximum lateral error of belt displacement of A and B motor was 0.009 7 mm and 0.006 0 mm,respectively.The average absolute error of X and Y axis lateral error was 0.357 mm and 0.362 mm,respectively.Compared with the PID control,the MPC control strategy had advantages of better indica-tors,easier parameter tuning and smaller lateral error,which improved the accuracy and efficiency of 3DP printer jet path,and solved the problems of parameter mismatch and low adaptability in traditional controls.With the decrease of the printing speed,the lateral error of MPC controller was gradually reduced,and the track tracking effect of the sys-tem was more accurate and stable.The MPC control strategy can update the prediction model within the control area according to the reference trajectory,solving the problem of actual printing deviation caused by mechanical structure in the X and Y axes,and effectively adjusting the actual motor speed and trajectory to enhance 3D printing efficiency.
3DP printermodel predictive control(MPC)trajectory trackingCoreXY mechanism3DP process
万方数据
维普
