Research On Embedded Micro-injection Molding Machine Control System

In order to meet the demands of micro-parts and micro-components, micro-injection molding technology opens up a new field for it since 1980s. The key point of Micro-injection molding technology is how to improve maching precision and control the injection capacity, which puts forward new requirements for control process.The conventional injection molding machine adopts the hydraulic/pneumatic controlling system, which has a slower response and poor control accuracy. With the development of mechatronics, the microcontroller system based on MCU appears. However, due to the disadvantages such as the limited computing capability of MCU, the open-loop control of position and pressure, it can not meet the accuracy requirements. So it's necessary to develop an embedded micro-controller which has faster processing speed and accuracy.This dissertation chooses FPGA and MCU as the core processor for full closed-loop control of position, pressure and temperature. The MCU is intended for the PID control of temperature, the open-loop control of pressure, all interrupts and orders during injection process; FPGA is used for the control of four motors, by which the computation of MCU is decreased and the hardware resources are effectively employed.First, the programs of communication and velocity-position control module are written on FPGA, then the four motors are controlled precisely by the parameters transmitted from the host computer. Second, the temperature and pressure control during injection process are implemented by PID algorithm in MCU. Finally, the control interface of host computer is compiled and some tests on the motion & temperature control are done, which shows that the response of the system is fast enough and can meet all requirements.In conclusion, this thesis carries out the velocity-position algorithm based on FPGA , it still provides interface for further extension and a reference on the realization of a more intelligent control algorithm by the conventional PID control. What is more, some contributions are made on how to decrease abnormal handling of MCU, the low injection speed, the poor precision of position , the slow response of two molding motors in abnormal state and the update of system function.