FDM工艺骨科3D打印机XY传动机构误差补偿策略

Error Compensation Strategy for Transmission Mechanism of XY Plane of Orthopaedic 3D Printer Based on FDM Technology

研究了FDM工艺骨科3D打印机串联机构误差传递的补偿策略。首先,针对FDM工艺骨科模型的打印特点和现有轮廓误差求取方法的不足,对轮廓误差的求取方法进行改进;然后,利用机械动力系统的拉格朗日方程,建立传动机构的动力学模型,推导传动机构的传递函数;最后,基于MATLAB/Simulink模块,建立开环系统、PID闭环系统和交叉耦合控制系统误差传递的仿真模型,模拟实际打印路径对3个控制系统模型进行仿真分析。结果表明,开环控制系统存在明显的跟踪误差和轮廓误差;两种补偿策略能够极大提高传动机构的动态性能。

An analysis for the contouring error transmition of the stepper-motor-synchronous-beh transmission mechanism used in 3D printer was conducted. The method of calculating the contouring error was improved to adapt to the characteristics of orthopaedic model＇s printing process. The kinetic model of the transmission mechanism was established by using the Lagrange equations for the mechanical power system. The open loop control model, PID closed loop control model and cross coupled control model were established. Furthermore, analysis of dynamic error propagation of the three models was conducted based on the simulation model. The results show that there is an obvious error of open loop control system. A better control effect can be achieved with PID controller and cross coupled controller.