3D-Surface-Model for Injection Speed Process

Injection velocity control in plastic injection molding is challenging as this process is inherently nonlinear, requiring an adaptive control strategy for good tracking of complex velocity trajectories. In this paper, a surface based model approach is developed tracking complex trajectories of injection velocity. This technique employs a 3-dimensional (3D) nonlinear surface model of the controlled variable (injection velocity) in the overall control architecture to calculate the manipulated variable or control action to a hydraulic servovalve. The strategy uses the controlled and manipulated variables as inputs to the 3D surface to update the nonlinear plant and controller parameters while the closed-loop control is executed, thereby handling the nonlinear characteristics of the plant being controlled.