On-line soft measurement modeling method for 4-CBA content based on least square algorithm of restricted memory part

A least squares, limited memory technology, applied in the field of 4-CBA content online soft sensor modeling, can solve the problems of complex structure, long model training time, small correlation degree of input variables, etc., and achieve the effect of high estimation accuracy

CN1570629AInactive Publication Date: 2005-01-26ZHEJIANG UNIV
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
Publication Date
2005-01-26
Estimated Expiration
Not applicable · inactive patent

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Abstract

This invention discloses a modeling method for on-line measuring 4-CBA contents based on limited -memory section of method of least square, which chooses nine most important process variables to 4-CBA content as assistance variables of flexible measuring model. And it employs the rolling correcting samples method of averaging and variance to bring information of old samples into the model to avoid missing information. The advantages of the invention are the following: 1, 4-CBA flexible measuring model is of linear model and of simple structure; 2, 4-CBA flexible measuring model is set up through rolling pattern with self-adaptation for systematic slow time-varying characteristics; 3, It employs l limited -memory section of method of least square to overcome saturation of sample; 4, the flexible measuring model of 4-CBA content is dynamic model with high accuracy.
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Description

technical field

[0001] The invention relates to an online soft sensor modeling method for 4-CBA content based on limited memory partial least squares algorithm. Background technique

[0002] PTA (Prified Terephthalic Acid) is one of the main raw materials for the production of polyester fibers. figure 1 It shows the basic technological process of p-xylene oxidation reaction by AMOCO method. p-xylene, acetic acid, mother liquor and catalyst cobalt, manganese and bromine are stirred evenly in the mixing tank, and the mixed solution is sent into the oxidation reactor and simultaneously into the oxidation reactor. The reactor also contains air. The oxidation process is carried out in two stages, the first stage takes place in the oxidation reactor and the second stage takes place in the first crystallizer. The reacted liquid is depressurized in the subsequent three crystallizers, condensed and then filtered and dried to obtain terephthalic acid (TA) and p-carboxybenzaldehyde (...

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Embodiment Construction

[0031] The present invention proposes a limited-memory partial least squares algorithm. In the rolling modeling process, every time a new sample is added, an old sample is removed, and the length of the data used for modeling remains unchanged. The invention uses limited memory partial least squares algorithm to establish the dynamic soft sensor model of the object on-line and rollingly. The scheme simultaneously considers the time-varying property of the object, the saturation of the sample and the external disturbance, so as to improve the estimation accuracy of the model. The invention includes an online rolling modeling method, an online correction algorithm for sample mean value and variance, and an algorithm for establishing a dynamic soft sensor model.

[0032] Explanation of terms:

[0033] PTA: PTA (Prified Terephthalic Acid) is one of the main raw materials for the production of polyester fibers. Its production method is as follows: the raw materials p-xylene, acet...