Laser power supply component performance detection method and system
Technical Field
The invention relates to the field of laser power supply detection, in particular to a method and a system for detecting performance of a laser power supply component.
Background
The laser power supply is a device capable of converting electric energy into light energy and is widely applied to the fields of laser communication, laser display, laser cutting, laser welding and the like. In order to ensure the performance and reliability of the laser power supply, a series of performance tests including static power test, dynamic power test, efficiency test, stability test, noise test, etc. are required.
The dynamic power test is a method for evaluating dynamic power performance of a laser power supply, currently, a dimmer is generally used for measurement, the laser power supply is connected to the dimmer and a power meter in the test process, the brightness of the dimmer is dynamically regulated, brightness readings and power meter numbers are recorded, and rated power, actual power, efficiency and other performance indexes of the power supply are evaluated according to the obtained brightness values and power values.
However, the existing testing method does not consider external influencing factors, such as environmental interference, battery state and the like, so that deviation occurs between a measurement result and a real situation, and the dynamic power performance of the detected laser power supply cannot be reflected truly. Therefore, we propose a method and system for detecting the performance of a laser power supply assembly.
Disclosure of Invention
The invention mainly aims to provide a method and a system for detecting the performance of a laser power supply assembly, which can effectively solve the problems in the background technology.
In order to achieve the above purpose, the invention adopts the technical proposal that,
A method for detecting performance of a laser power supply assembly, comprising:
The method comprises the steps of connecting a power supply to be detected to a dimmer and a power meter, dynamically adjusting the brightness of the dimmer, and sampling performance index parameters, brightness values, environment parameters and state-of-charge values of the dimmer in the process that the power supply to be detected is continuously discharged from an upper limit SOC max to a lower limit SOC min of the state of charge, wherein the performance index parameters comprise rated power, actual power and conversion efficiency, the environment parameters comprise the running temperature of the power supply to be detected and the humidity of the environment, the value range of the upper limit SOC max of the state of charge is [0.8,0.9], and the value range of the lower limit SOC min of the state of charge is [0.15,0.2];
Calculating local outlier factors in the performance index parameters by using an LOF algorithm, judging whether a j sampling value x ij of an i-th performance index is abnormal data or not by using the obtained local outlier factors, screening and removing the abnormal data in the sampling values of the performance index parameters, wherein the judging process comprises the following steps:
The distance value D i(j-q) between the sampling value x ij and the rest sampling value x iq is calculated respectively, and the calculation formula is as follows: wherein j and q are N, q is not equal to j, and N is the total amount of sampling data;
Sequentially sorting the obtained distance values D i(j-q) from small to large, setting the kth element closest to the sampling value x ij as x ip, p epsilon N, and p not equal to j, obtaining a kth distance value D k(xij of the sampling value x ij and the sampling value x ip), wherein,
A kth distance neighborhood N k(xij) of the sampling value x ij is determined from the kth distance value d k(xij);
Obtaining the kth reachable distance of the sampling value x ij, wherein ,dk(xij,xip)=max[dk(xij),d(xij,xip)],dk(xij,xip) is the kth reachable distance of the sampling value x ij, max [ d k(xij),d(xij,xip) ] is the maximum value in d k(xij)、d(xij,xip), and d (x ij,xip) is the distance value set between the sampling value x ij and all elements in the kth distance neighborhood N k(xij);
Obtaining a local reachable density of the sampling value x ij, wherein the local reachable density is defined as:
and calculating a local outlier factor of a sampling value x ij according to the acquired local reachable density, wherein a calculation formula is as follows:
Where LOF k(xij) is the local outlier of sample value x ij and ρ k(xip) is the local reachable density of sample value x ip;
And judging the abnormal condition of the sampling value x ij by using the acquired local outlier factor, wherein the judging principle is as follows:
When LOF k(xij) >1, it means that the sampling value x ij is likely to be abnormal data, and when LOF k(xij) is larger, the data abnormality degree is more likely;
When LOF k(xij) is close to 1, it means that the sampling value x ij may belong to the same cluster as the neighborhood point, and is normal data;
When LOF k(xij) <1, it means that the sample value x ij is a dense data point;
Normalizing the screened performance index parameters, the brightness value of the dimmer, the environment parameters and the state of charge value to a [0,1] interval, wherein a normalization processing formula is as follows:
Wherein x' is represented as a data value after normalization processing, x is represented as a data value before non-normalization processing, x max、xmin is respectively represented as a maximum value and a minimum value in the data before non-normalization processing, a brightness value, an environment parameter and a charge state sampling value of a light modulator after normalization processing are taken as input data, a corresponding performance index parameter sampling value after normalization processing is taken as output data, a BP neural network model is constructed, the established neural network model is trained, a target error and the maximum circulation number of the network model are set, when the number of hidden layers of the model is adjusted to be not lower than a predicted accuracy according to the error of a training result, a neural network model for predicting the performance index parameter is obtained, and a calculation formula of a predicted accuracy expected value is that,
Wherein E (Y) is expressed as a predicted accuracy expected value, Q is expressed as an input sample size of the neural network, f (X k) is expressed as an output function of the neural network, X k is expressed as a kth output sample of the neural network;
Obtaining a predicted value of the performance index parameter of the power supply to be detected by using the constructed neural network model, and calculating a correction coefficient k i of each performance index parameter according to the obtained predicted value, wherein the calculation formula is as follows: Wherein, Q is represented as the input sample size of the neural network, x' ij is represented as the predicted value of the performance index parameter obtained by using the neural network model, the sampling value of the performance index parameter is corrected by a correction coefficient k i, the correction value of each performance index parameter is obtained, and the calculation formula is as follows:
A performance detection system of a laser power supply assembly comprises a dimmer, a power meter, a dynamic adjustment module, an environmental parameter acquisition module, a state of charge acquisition module, a data processing module, a neural network construction module and a data correction module;
The light modulator is connected with a power supply to be detected and is used for acquiring a light modulator brightness sampling value in the process that the power supply to be detected is continuously discharged from the state of charge upper limit SOC max to the state of charge lower limit SOC min;
The power meter is connected with the power supply to be detected and is used for acquiring a performance index parameter sampling value comprising rated power, actual power and conversion efficiency in the process that the power supply to be detected is continuously discharged from the state of charge upper limit SOC max to the state of charge lower limit SOC min;
the dynamic adjustment module is used for dynamically adjusting the brightness value of the dimmer in the process that the power supply to be detected is continuously discharged from the upper limit SOC max to the lower limit SOC min;
The environment parameter acquisition module is used for acquiring an environment parameter sampling value comprising the running temperature of the power supply to be detected and the humidity of the environment in the process of continuously discharging the power supply to be detected from the upper limit SOC max to the lower limit SOC min;
The charge state acquisition module is used for acquiring a charge state sampling value of the power supply to be detected;
The data processing module is used for calculating local outlier factors in the performance index parameters by adopting an LOF algorithm, judging whether a j sampling value x ij of an i-th performance index is abnormal data or not by utilizing the obtained local outlier factors, and screening and eliminating the abnormal data in the sampling values of the performance index parameters;
The neural network construction module is used for constructing a BP neural network model which takes a normalized light modulator brightness value, an environment parameter and a charge state sampling value as input data and a corresponding normalized performance index parameter sampling value as output data, training the established neural network model, setting a target error and a maximum circulation number of the network model, and obtaining the neural network model for predicting the performance index parameter when the number of hidden layers of the model is adjusted to be not lower than an expected value according to the error of a training result;
The data correction module is used for obtaining predicted values of the performance index parameters of the power supply to be detected by using the constructed neural network model, and calculating correction coefficients k i of the performance index parameters according to the obtained predicted values, wherein the calculation formula is as follows: Wherein, Q is represented as the input sample size of the neural network, x' ij is represented as the predicted value of the performance index parameter obtained by using the neural network model, the sampling value of the performance index parameter is corrected by a correction coefficient k i, the correction value of each performance index parameter is obtained, and the calculation formula is as follows:
The system includes a memory, a processor, and a computer program stored on the memory and executable on the processor.
The invention has the following advantages that,
Compared with the prior art, the method has the advantages that the performance index parameters and the brightness value, the environment parameter and the state of charge value of the dimmer in the process of continuously discharging the power supply to be detected from the state of charge upper limit SOC max to the state of charge lower limit SOC min are sampled, abnormal data in the performance index parameter sampling values are screened and removed for normalization processing, the normalized dimmer brightness value, the environment parameter and the state of charge sampling value are taken as input data, the corresponding normalized performance index parameter sampling values are taken as output data, a BP neural network model is constructed and trained, the constructed neural network model is utilized to obtain the predicted value of the performance index parameters of the power supply to be detected, the correction coefficient k i of each performance index parameter is calculated according to the obtained predicted value, the sampling value of each performance index parameter is corrected through the correction coefficient k i, the influence of external influence factors such as environment interference and battery state on the dynamic power performance measurement process of the laser power supply is fully considered, the accuracy of the measurement result is improved by correcting the measurement result, and the dynamic power performance of the power supply is reflected.
Drawings
FIG. 1 is a flow chart of a method for detecting performance of a laser power supply assembly according to the present invention;
FIG. 2 is a block diagram of a laser power module performance detection system according to the present invention;
Fig. 3 is a block diagram of a neural network constructed in the scheme of the present invention.
Detailed Description
The present invention will be further described with reference to the following detailed description, wherein the drawings are for illustrative purposes only and are presented as schematic drawings, rather than physical drawings, and are not to be construed as limiting the invention, and wherein certain components of the drawings are omitted, enlarged or reduced in order to better illustrate the detailed description of the present invention, and are not representative of the actual product dimensions.
The specific implementation flow of the technical scheme of the invention comprises the following steps:
Step 1, connecting a power supply to be detected into a dimmer and a power meter, dynamically adjusting the brightness of the dimmer, and sampling performance index parameters, brightness values, environment parameters and state of charge values of the dimmer in the process that the power supply to be detected is continuously discharged from an upper limit of state of charge SOC max to a lower limit of state of charge SOC min;
The performance index parameters comprise rated power, actual power and conversion efficiency, the environment parameters comprise the running temperature of a power supply to be detected and the humidity of the environment, the value range of the SOC max is [0.8,0.9], and the value range of the SOC min is [0.15,0.2];
The specific steps of measuring rated power, actual power and efficiency of a power supply by using a power meter are as follows:
Checking whether the power meter is intact, and ensuring no damage, no rust, no looseness and the like. The stable power supply voltage and the firm connection of the power supply wires are ensured, and the power meter is prevented from being installed in an environment influenced by vibration, moisture and high temperature so as to ensure the stable operation of equipment;
According to the characteristics of the circuit and the requirements of the power meter, a proper connection mode, such as serial connection or parallel connection, is selected, and the circuit to be tested is correctly connected to the input end of the power meter, so that firm connection and good contact are ensured;
Before using the power meter, calibration must be performed to ensure accuracy, and measurement parameters such as power range, sampling rate, display format, etc. are set according to actual requirements;
The stable circuit operates, avoids interference and fluctuation, and selects a measurement function;
Reading a measurement result, observing whether the display is stable or not, and avoiding measurement errors caused by jitter or instability;
The monitored data is recorded, and the rated and actual power, and efficiency of the power supply are calculated.
The calculation formula of the power efficiency is η=P out/Pin ×100%, wherein P out is the output power of the power supply, P in is the input power of the power supply, and in the measurement process, a power meter can be used for directly measuring the output voltage and current to obtain the output power, and meanwhile, the input voltage and current are measured to obtain the input power;
Step 2, calculating local outlier factors in the performance index parameters by using an LOF algorithm, judging whether a j sampling value x ij of the i-th performance index is abnormal data or not by using the obtained local outlier factors, screening and removing the abnormal data in the sampling values of the performance index parameters, wherein the judging process comprises the following steps:
Step 21, respectively calculating a distance value D i(j-q) between the sampling value x ij and the rest sampling values x iq, wherein the calculation formula is as follows: wherein j and q are N, q is not equal to j, and N is the total amount of sampling data;
Step 22, sequentially sorting the obtained distance values D i(j-q) from small to large, setting the kth element closest to the sampling value x ij as x ip, p epsilon N, and p not equal to j, obtaining a kth distance value D k(xij of the sampling value x ij and the sampling value x ip),
Step 23, determining a kth distance neighborhood N k(xij of the sampling value x ij according to the kth distance value d k(xij);
Step 24, obtaining the kth reachable distance of the sampling value x ij, wherein ,dk(xij,xip)=max[dk(xij),d(xij,xip)],dk(xij,xip) is the kth reachable distance of the sampling value x ij, max [ d k(xij),d(xij,xip) ] is the maximum value operation in d k(xij)、d(xij,xip), and d (x ij,xip) is the distance value set between the sampling value x ij and all elements in the kth distance neighborhood N k(xij);
Step 25, obtaining a local reachable density of the sampling value x ij, wherein the local reachable density is defined as:
Step 26, calculating a local outlier factor of the sampling value x ij according to the acquired local reachable density, wherein the calculation formula is as follows:
Where LOF k(xij) is the local outlier of sample value x ij and ρ k(xip) is the local reachable density of sample value x ip;
step 27, judging the abnormal condition of the sampling value x ij by using the obtained local outlier factor, wherein the judging principle is as follows:
When LOF k(xij) >1, it means that the sampling value x ij is likely to be abnormal data, and when LOF k(xij) is larger, the data abnormality degree is more likely;
When LOF k(xij) is close to 1, it means that the sampling value x ij may belong to the same cluster as the neighborhood point, and is normal data;
When LOF k(xij) <1, it means that the sample value x ij is a dense data point;
step 3, normalizing the screened performance index parameters, the brightness value of the dimmer, the environment parameters and the state of charge value to a [0,1] interval, wherein the normalization processing formula is as follows:
Wherein x' is represented as a numerical value after normalization processing, x is represented as a data value before non-normalization processing, x max、xmin is respectively represented as a maximum value and a minimum value in the data before non-normalization processing, a brightness value, an environment parameter and a charge state sampling value of a light modulator after normalization processing are taken as input data, a corresponding performance index parameter sampling value after normalization processing is taken as output data, a BP neural network model is built, the built neural network model is trained, a target error and the maximum circulation number of the network model are set, when the number of hidden layers of the model is adjusted to be not lower than a desired value according to the error of a training result, a neural network model for predicting the performance index parameter is obtained, and a calculation formula of the desired value of the prediction accuracy is that,
Wherein E (Y) is expressed as a predicted accuracy expected value, Q is expressed as an input sample size of the neural network, f (X k) is expressed as an output function of the neural network, X k is expressed as a kth output sample of the neural network;
For the BP neural network model in the scheme, the input layer comprises a dimmer brightness value, the running temperature of a power supply to be detected, the humidity of the environment and the state of charge, the number of neuron nodes of the input layer is 4, the output layer comprises rated power, actual power and conversion efficiency, the number of neuron nodes of the output layer is 3, the number of neuron nodes of the middle layer can be determined according to an empirical formula, and the method specifically comprises the following steps: wherein a is a constant of 1 to 9, Represented as a pair ofThe calculation results of (2) are rounded upwards, so that the structure of the neural network can be determined to be the input layer of 4 neuron nodes, the middle layer of s neuron nodes and the output layer structure of 3 neuron nodes, as shown in fig. 3;
In this embodiment, taking a neural network model construction by using MATLAB software as an example, training a network by using a standard BP neural network algorithm, setting a target error and a maximum cycle number, selecting an S-type tangent function tansig from a transfer function of a hidden layer neuron, selecting an S-type logarithmic function logsig from a transfer function of an output layer neuron, selecting a traingdx function as a training function, and continuously adjusting the number of intermediate layer neuron nodes to enable the prediction accuracy to be not lower than an expected value, thereby obtaining a neural network model for predicting performance index parameters;
And 4, acquiring predicted values of the performance index parameters of the power supply to be detected by using the constructed neural network model, and calculating correction coefficients k i of the performance index parameters according to the acquired predicted values, wherein the calculation formula is as follows: Wherein, Q is represented as the input sample size of the neural network, x' ij is represented as the predicted value of the performance index parameter obtained by using the neural network model, the sampling value of the performance index parameter is corrected by a correction coefficient k i, the correction value of each performance index parameter is obtained, and the calculation formula is as follows:
The foregoing has shown and described the basic principles and main features of the present invention and the advantages of the present invention. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, and that the above embodiments and descriptions are merely illustrative of the principles of the present invention, and various changes and modifications may be made without departing from the spirit and scope of the invention, which is defined in the appended claims. The scope of the invention is defined by the appended claims and equivalents thereof.