A method for a modeling system for collected data of sensors on a numerical control machine tool, wherein the modeling system comprises a controller, and the method runs on the controller, and comprises the following steps:
- step 1:
- a plurality of sensors transmitting collected p-channel data to the controller through a multi-channel sensor interface circuit, and the controller converting a received p-channel data into tensor-data-one of a p-channel, the tensor-data-one of the p-channel comprising n sample data collected by the plurality of sensors, each sample data comprising data collected by the plurality of sensors at a certain sampling time, and wherein data format of an i-th sample data Yi(t) being:
- Yi(t)=[Yil(t), . . . , Yip(t)], t is a sampling time of the i-th sample data;
- Yij(t) is expressed by a formula (1):
- Yij(t)=Xij(t)+εij(t) (1)
- wherein Xij(t) is a signal function of the collected data of a jth channel, εij(t) is a noise function of the collected data of the j-th channel, i is a positive integer less than or equal to N, j is a positive integer less than or equal to p, Yij(t) represents the collected data of the j-th channel at a sampling time t;
- step 2:
- setting a data format of a tensor-data-two of the p channel Xi(t) as:
- Xi(t)=[Xil(t), . . . , Xip(t)], wherein the tensor-data-two of the p channel Xi(t) is divided into L sample subspaces SI, 1=1, 2, . . . , L, L is a positive integer, in a same sample subspace, signal functions corresponding to each signal have cross-correlation, the signal functions corresponding to each signal in different sample subspaces have no correlation;
- step 3:
- setting each sample subspace Sl as a linear superposition of Φl of dl basis functions, as shown in formula (2), wherein Φl=[Φl1(t), . . . , Φldl(t)]:
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- wherein for all signal functions Xij(t), I=1, . . . ,N, sample subspace to which Xij(t) belongs remains unchanged, while basis coefficients αij corresponding to Xij(t) are different, and αijk is a k-th component of the basis coefficients αij, where k is a positive integer less than or equal to dl;
- wherein Xl represent the signals of the respective sample subspaces, wherein Xl={Xj(t)|Xj(t)∈Sl, j=1, . . . , p}, q and dl are both positive integers, and αq is a set real number, R is a set of real numbers;
- step 4:
- obtaining formula (3) for each signal Xij(t), Xij(t)∈Xl, according to self-expression property of data that each data point in the sample subspace can be jointly represented by other data points in a data set:
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- that is, Xij(t) is a signal function in Xl, which can be expressed as a linear combination of other pl-1 signals in this sample subspace, r is a positive integer, and bjr is a rth component of a sparse coefficient;
- step 5:
- using an Lq norm to minimize an objective function to limit solution set for a solution of a sparse coefficient bj;
- wherein the modeling system comprises a computer-one, the method runs on the computer-one, and further comprises the following steps:
- the computer-one building an information link between the computer-one and a computer-two;
- the computer-one sending a number of reduced information frames with the sparse coefficient to the computer-two, based on the conditions of the information link between the computer-one and the computer-two;
- wherein the computer-one sends different reduced information frames of the sparse coefficients under the conditions of different information links;
- after the computer-one sending a number of reduced information frames with the sparse coefficient to the computer-two, based on the conditions of the information link between the computer-one and the computer-two, the computer-one monitoring whether the information link between the computer-one and computer two is interrupted;
- when so, the computer-one registers reduced information frames of the sparse coefficient which are not sent or sent unsuccessfully, and the reduced information frames of the sparse coefficient which are not sent or sent unsuccessfully are registered as not sent;
- when the computer-one and the computer-two restore the information link, the computer-one sends a number of reduced information frames of the sparse coefficient that registered as not sent to the computer-two.