Research On Key Control Algorithm Of Electro-hydraulic Injection Molding Machine With Drivers Integrated

Injection molding machine is the main forming equipment of plastic products which are made of thermoplastic or thermosetting plastic by using plastic molding mould to form different shapes and sizes. Although the shape of the structure and transmission principle after decades of development injection molding machine does not change much, but the injection molding machine control technology and ideas is constantly developing innovative, tend to be more intelligent control. With the improvement of the quality of the product components, precision injection molding machine control requirements are also increasing.Currently the clamping mechanism of injection molding machine is graded open-loop control, which there is a big position error. The positioning accuracy of the mold is important to the location point of the high pressure of the injection molding machine, and also can cause the impact damage to the mold. The mold positioning accuracy will affect the robot, so the robot pickup requirements open position must stop within the set range of open-stop position. So the research on the positioning accuracy of the clamping mechanism has important significance.First of all, the paper briefly introduces the injection molding machine in the history of the development on energy conservation and environmental protection, and then focus on problems of the control and drive system part of L.K. Group’s electro-hydraulic injection molding machine, using the equipment with drivers integrated of Googoltech Company to replace the original drive and control system, rewiring the circuit and optimization of the injection molding process, so the new software control system could be more safety and reliable.Further, the research progress of iterative learning control is discussed. Iterative learning control does not need precise mathematical model of the controlled object, algorithm is simple, only need a small amount of a priori knowledge and computation, can revised control input constantly, according to the error of the system, then the output system could be close to the desired output trajectory. It is very suitable for solving the complex and uncertain systems which are difficult to control by traditional control. It is widely used in the controlled object with repetitive motion, such as injection molding machine.Finally, this paper focuses on the iterative learning control positioning precision in injection molding machine mold opening and closing mechanism was studied, In the understanding of the oil transmission delay of the injection molding machine control cause larger errors in the mold, through the comparison of the iterative control P-type learning law, variable gain P-type learning law and PID type learning law, with forgetting factor PID type learning law on the positioning precision of the mold, reducing the errors from more than 15 mm to ±0.5 mm, to achieve the high precision control, so iterative control algorithm is verified on the process control, the effect of injection molding machine combined with the manipulator in the future to take control has the very good application value.