Tool wear monitoring and predicting method
AssigneeNational Cheng Kung University
InventorsHaw-Ching Yang, Fan-Tien Cheng
Life of this patent
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Abstract
A tool wear monitoring and predicting method is provided, and uses a hybrid dynamic neural network (HDNN) to build a tool wear prediction model. The tool wear prediction model adopts actual machining (cutting) conductions, sensing data detected at the current tool run of operation and the predicted tool wear value at the previous tool run of operation to predict a predicted tool wear value at the current tool run. A cyber physical agent (CPA) is adopted for simultaneously monitoring and predicting tool wear values of plural machines of the same machine type.
Claims9
A tool wear monitoring and predicting method, comprising:
- obtaining ranges of a plurality of sets of factory machining conditions regarding a cutting tool product, wherein the ranges of the sets of factory machining conditions have a plurality of boundary conditions enclosing an area of feasible machining conditions;
- respectively performing a plurality of life-determining operations on a plurality of first cutting tools in accordance with the boundary conditions, thereby obtaining a plurality of actual maximum tool life values of the cutting tool product that are operated at the boundary conditions respectively, wherein the first cutting tools have the same type as the cutting tool product, and in each of the life-determining operations, one of the first cutting tools is continuously operated from its brand new condition until it is completely inoperable;
- obtaining a maximum tool life (MTL) of a second cutting tool under a set of actual machining conditions in accordance with a Taylor's tool life equation by using the actual maximum tool life values and the boundary conditions, wherein the second cutting tool has the same type as the cutting tool product;
- sequentially performing a plurality of historical tool runs of operation using the second cutting tool under the set of actual machining conditions, thereby obtaining a relationship of actual tool wear to tool life, a plurality of sets of historical sensing data and a plurality of historical tool wear values, wherein the historical tool wear values are corresponding to the sets of historical sensing data and the historical runs of operation in a one-to-one manner;
- building a tool wear prediction model in accordance with a hybrid dynamic neural network (HDNN) algorithm by using the set of historical sensing data and the historical tool wear values;
- obtaining a plurality of sets of sensing data of a third cutting tool that is sequentially performing a plurality of tool runs of operation under the set of actual machining conditions, wherein the third cutting tool has the same type as the cutting tool product, and the tool runs of operation are corresponding to the sets of sensing data in a one-to-one manner;
- inputting the sets of sensing data and the maximum tool life into the tool wear prediction model, thereby obtaining a tool wear predicted value of the third cutting tool after each of the tool runs of operation, wherein, when the tool wear predicted value of the third cutting tool after the each of the tool runs of operation is desired to be predicted, the tool wear predicted value of the third cutting tool at the tool run of operation right before the each of the tool runs of operation is required to be inputted into the tool wear prediction model;
- calculating a remaining useful life (RUL) of the third cutting tool by using the tool wear predicted value, the maximum tool life and the maximum tool wear threshold;
- and
- replacing the third cutting tool with a new cutting tool when the tool wear predicted value is greater than or equal to a maximum tool wear threshold.
Dependencies are inferred from the claim text.