On-line monitoring method for injection molding process

Abstract

The invention discloses an on-line monitoring method for an injection molding process and belongs to the field of process monitoring. The on-line monitoring method comprises the following steps: acquiring process variables in the injection molding process, and calculating characteristic quantity vectors of the process variables of production batches; taking the characteristic quantity vectors of the process variables of the plurality of qualified production batches as basis, and calculating to obtain a monitoring template SPmodel and a monitoring control limit Dmodel; calculating according to the monitoring template, the monitoring control limit, and the characteristic quantity vector Spz of a Zth batch in a current production process to obtain a monitoring quantity Dz and a monitoring index Tz of the Zth batch; when the Tz is less than or equal to 1, judging that the production process of the Zth batch is qualified; and when the Tz is more than 1, judging that the production process of the Zth batch is abnormal. According to the method, extra equipment and funds do not need to be used and the economic cost is low; a batch data alignment problem and a Gaussian assumption problem in a PCA method are avoided; and the system drift in the injection molding process can be adapted very well, and an injection molding production process can be controlled according to expectation.

Description

Technical field [0001] The invention belongs to the field of process monitoring, and more specifically, relates to an injection molding process online monitoring method based on multi-period statistical mode analysis. Background technique [0002] Batch production process, that is, batch production process, refers to the process of processing raw materials into products that meet quality requirements in a limited time and with pre-designed procedures. The batch production process usually consists of multiple processes, and each process has multiple control variables. In the batch production process, due to the uncertainty of the running time of each process, the complexity of the reaction, the time variability of variables, and the correlation between variables and variables, it is difficult to establish a batch production process based on a mechanism model The relationship with product quality. [0003] The injection molding process is a typical batch production process. The inj...

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Problems solved by technology

[0006] Aiming at the above defects or improvement needs of the prior art, the present invention provides an online monitoring method in the injection molding process, the purpose of which is to establish a new real-time monitoring injection molding model for monitoring different batches of Different process variables in different stages can reflect the fluctuation of the quality of injection molding products, and can also give feedback and automatically update when the monitored process variables fluctuate too much. The model has high accuracy and can ensure the quality of products between different batches. Consistency, thereby solving the technical problems of the existing injection molding process monitoring methods, such as low model accuracy, inability to update in time and prone to false positives

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