Patent ID: 9715220
Date: 2017-07-25
CPC Classifications: B29C,G05B

Claim:
1. A method for real-time controlling a resin transfer molding process, which is used to control a filling pressure of a resin in a resin transfer molding (RTM) apparatus, wherein the RTM apparatus comprises a resin supply unit and a molding unit connected with the resin supply unit, and wherein the molding unit includes a mold cavity accommodating a pre-woven fiber object (a preform) and a plane inside the mold cavity, and wherein the method comprises: Step 1: establishing a plurality of groups of process training conditions, wherein the process training conditions include an initial filling pressure; Step 2, performing a plurality of training processes according to the process training conditions to acquire a permeability of the resin, a wave front position of the resin at a current time point and a wave front position of the resin at a next time point for a plurality of time points of each training process, wherein the permeability, the wave front position at the current time point and the wave front position at the next time point are acquired with Steps 2A-2F: Step 2A: defining on the plane a plurality of detection positions y Step 2B: providing a detection module including a pressure transducer unit, at least one image capture device and a processing unit, wherein the pressure transducer unit is arranged in the detection positions y Step 2C: filling the resin into the mold cavity with the initial filling pressure and letting the resin flow on the plane along a direction; Step 2D: using the image capture device to obtain positions of the resin on the plane at a time point t Step 2E: setting i and j to be preset values α and r respectively, wherein r is an integer greater than 1 and α is an integer greater than or equal to 1; using the image capture device to obtain the measurement positions x Step 2F: using the processing unit to obtain the permeability K wherein ψ is a porosity of the preform, μ a fluid viscosity of the resin, ΔT=t Step 2G: repeating Steps 2A-2F to acquire the permeability, the wave front position at the current time point and the wave front position at the next time point of the resin for a plurality of time points in the training process; Step 3: defining the initial filling pressure, the permeability and the wave front position at the current time point as an input, and defining the wave front position at the next time point as an output; using a data mining technology to establish a prediction-control model involving the input and the output, which is expressed as wherein P Step 4: performing a process to be controlled, which uses Steps 2A-2F to acquire the permeability at the current time point and the wave front position at the current time point, using an optimization algorithm to select at least one candidate filling pressure, and substituting the candidate filling pressure, the permeability at the current time point and the wave front position at the current time point into the prediction-control model, which is established in Step 3, to acquire at least one candidate wave front position at the next time point corresponding to the candidate filling pressure; Step 5: comparing the candidate wave front positions at the next time point, which are acquired in Step 4, with the expected wave front position at the next time point to find out the candidate wave front position at the next time point, which is nearest to the expected wave front position at the next time point, and using the result to trace back the corresponding candidate filling pressure; Step 6: transmitting the candidate filling pressure to the resin supply unit, and using the candidate filling pressure as the filling pressure of the next time point to make the resin flow to the expected position of the wave front of the next time point.