CN113607405A - Digital valve group multi-fault detection device and diagnosis method thereof - Google Patents
Digital valve group multi-fault detection device and diagnosis method thereof Download PDFInfo
- Publication number
- CN113607405A CN113607405A CN202110859572.5A CN202110859572A CN113607405A CN 113607405 A CN113607405 A CN 113607405A CN 202110859572 A CN202110859572 A CN 202110859572A CN 113607405 A CN113607405 A CN 113607405A
- Authority
- CN
- China
- Prior art keywords
- flow
- valve group
- fault
- valves
- valve
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
- G01M13/00—Testing of machine parts
- G01M13/003—Machine valves
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
- G01D21/00—Measuring or testing not otherwise provided for
- G01D21/02—Measuring two or more variables by means not covered by a single other subclass
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Testing Of Devices, Machine Parts, Or Other Structures Thereof (AREA)
Abstract
The invention relates to the technical field of digital hydraulic component fault diagnosis, in particular to a digital valve group multi-fault detection device and a diagnosis method thereof, wherein a digital valve group, a control system module, a pressure sensor, a flow sensor, a pressure source and an oil outlet are connected in parallel through a control circuit; the high-speed switch valves in the digital valve group can be any number, are not limited by the number, have strong expansibility, are not limited by a flow coding mode, are suitable for equal coding, binary coding and Fibonacci coding, simply and efficiently diagnose faults, improve the accuracy of multi-mode faults, meet the requirement of complex working conditions that a plurality of valves have different faults at the same time, and reduce the diagnosis and maintenance cost.
Description
Technical Field
The invention relates to the technical field of digital hydraulic component fault diagnosis, in particular to a digital valve group multi-fault detection device and a diagnosis method thereof.
Background
The digital hydraulic pressure becomes the leading edge and the hot spot of the research of the modern fluid transmission technology with the advantages of energy conservation, good fault tolerance, strong interchangeability, high cost performance, strong pollution resistance and the like. The digital valve group is constructed by connecting a plurality of small-flow gain digital valves in parallel, continuous control can be approximately realized through digital switch combination, the redundancy and the reliability of the system are improved, and the original frequency characteristic can be kept. Furthermore, the digital valve block has a redundant feature compared to conventional hydraulic valves. Due to the fact that the number valve bank is increased in composition links and influence factors, the probability of faults and functional failures is gradually increased, the sensitivity to the faults is higher and higher, and the accuracy, the stability and the like of the number valve during the faults can have negative influences on the whole hydraulic system. The single-valve fault diagnosis method needs more sensors, is complex in data processing and large in limitation, has a single fault diagnosis mode of the conventional digital valve bank, cannot judge the complex conditions of multiple faults of multiple valves, is low in diagnosis accuracy rate, and lacks a simple, effective and accurate fault diagnosis method, especially a fault diagnosis method with less sensors.
Disclosure of Invention
Aiming at the defects, the invention aims to solve the problems that the existing fault diagnosis method based on a single valve is not suitable for the online diagnosis of the complex fault of the digital valve group and the dependence on more sensors is avoided; the method aims at the problems that the existing digital valve group fault diagnosis method is single in fault diagnosis, cannot give consideration to the situation that different faults occur to multiple valves at the same time, and is low in accuracy rate and the like.
In order to achieve the purpose, the invention provides the following technical scheme:
a digital valve pack multiple fault detection device, comprising: the digital valve bank (1), the control system module (7), the pressure sensor (3), the flow sensor (4), the pressure source (5) and the oil outlet (6) are connected in parallel through the control circuit (2);
the digital valve group (1) is mainly formed by connecting four switch valves with the same flow grade, a controller, a flow sensor and a pressure sensor in parallel;
the pressure source (5) is mainly provided with a hydraulic pump connected with an oil tank;
the end of the oil outlet (6) is electrically connected with an actuator;
the control system module (7) mainly comprises an acquisition card, an upper computer, an adjustable direct-current power supply, a small-flow electromagnetic switch valve, a pressure sensor (3) and a flow sensor (4), wherein a first end of the adjustable direct-current power supply is electrically connected with a control end of the acquisition card, a second end of the adjustable direct-current power supply is electrically connected with a power end of a coil of the small-flow electromagnetic switch valve, the flow sensor (4) is connected with an outlet of a digital valve group (1) in series, the pressure sensor (3) is electrically connected with an outlet and an inlet of the digital valve group (1), an acquisition end of the acquisition card is electrically connected with output ends of the flow sensor (4) and the pressure sensor (3), and an output end of the acquisition card is electrically connected with the upper computer through a wire cable.
A digital valve group multi-fault diagnosis method comprises the following steps: inputting signals, coding the signals, comparing a fault model library, accumulating deviations and judging the minimum value;
signal input: the input signals mainly comprise a control signal U and a differential pressure signal delta p acquired by pressure sensors (3) in front of and behind a digital valve group (1); wherein, UiIs a four-dimensional column vector representing the control signals of the four digital valves at the ith moment;
signal coding: control signal vector UiThe binary signal in the control vector is converted into a decimal numerical value, namely a signal code ui of the control vector at the moment, and the change of the signal code is used for making a difference and accumulating a triggering condition;
comparing a fault model library: five fault states of no opening, no closing, no complete opening, no complete closing and blocking independently occur to each valve, a combined state of any fault occurs to any number of valves, and all valves are in normal states; the actual flow Q of the digital valve group and the current control signal U are obtained when the signal code changes oncei1296 model flows Q under differential pressure delta p1(Ui),…,Q21(Ui) Respectively carrying out difference and obtaining absolute values to obtain deviation e1n,…,e1296n;
And (3) deviation accumulation: when the signal code changes once, the deviation of each flow model under the current condition is accumulated once to obtain the deviation sum E1,…,E1296Representing the degree of deviation of the actual flow from the 1296 flow models;
and (3) minimum value judgment: comparing E over a period of time1,…,E1296To obtain the minimum value ExWhen the current state is the closest to the x-th state, the position of the fault valve can be judgedSet, number, and type of failure.
The technical scheme of the invention is further improved as follows: the fault type is judged by modeling all faults which can occur to all digital valves and comparing the difference sum of the actual flow and the model flow in a period of time.
The technical scheme of the invention is further improved as follows: there is no requirement for control signals and no connection between signals, and in addition, the diagnostic method has no requirement for pressure, i.e. is suitable for various operating conditions.
The technical scheme of the invention is further improved as follows: the difference between the actual flow of the valve group and the model flow in a period of time can be compared to judge that any valve or valve cores of the valves can not be opened, closed or clamped in the middle, can not be opened completely, can not be closed completely and can be in normal six states.
The technical scheme of the invention is further improved as follows: the method can be used for simultaneously solving the problem that a plurality of valves have faults, and the positions, the number and the fault types of the fault valves can be judged.
Compared with the prior art, the digital valve group multi-fault detection device and the diagnosis method thereof have the beneficial effects that:
1. the invention is based on the digital valve group fault flow model, and can effectively improve the accuracy of fault diagnosis by performing difference operation on the actual flow output of the digital valve group and various flow models and accumulating and gradually amplifying deviations.
2. The invention overcomes the complex process of the existing online diagnosis method depending on statistical data, quantile regression and other methods, and the flow is simpler.
3. Compared with some fault diagnosis methods based on single valves, the method only needs to rely on flow and pressure sensors of a hydraulic system, does not need to use extra current, vibration sensors and the like, avoids the processing process of a large amount of data, and enables the valve group to be smaller in size and lighter in weight.
4. The invention can diagnose a plurality of fault modes, has accuracy and rapidity which are not influenced by the number of valves, and can realize rapid and accurate fault diagnosis on occasions with frequent control signal changes.
5. The invention is not limited to single valve fault, can diagnose the condition of different faults of a plurality of valves, and is suitable for various complex working condition environments.
6. The method is not limited by a flow coding mode of the switching valve, and is suitable for equal coding, binary coding, Fibonacci coding and the like.
7. The invention can realize on-line real-time diagnosis, has less data quantity compared with other on-line diagnosis methods, and reduces the operation pressure of the controller.
8. The invention has the greatest advantages of being suitable for various working conditions, free from the influence of application scenes (any speed and pressure) and wide in application occasions.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.
Fig. 1 is a hydraulic principle schematic diagram of a digital valve group of the invention.
Fig. 2 is a schematic diagram of a diagnostic method of the digital valve group multi-fault detection device of the present invention.
Reference numbers in the figures: 1-a digital valve pack; 2-a control circuit; 3-a pressure sensor; 4-a flow sensor; 5-a pressure source; 6-oil outlet; 7-control system module.
Detailed Description
The technical solution of the present invention will be clearly and completely described by the following detailed description. It is to be understood that the described embodiments are merely exemplary of the invention, and not restrictive of the full scope of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
The invention is explained in detail with reference to the drawings:
as shown in fig. 1, in the digital valve group multi-fault detection device, a digital valve group (1), a control system module (7), a pressure sensor (3), a flow sensor (4), a pressure source (5) and an oil outlet (6) are connected in parallel through a control circuit (2), the pressure source (5) is connected with an oil source, and the oil outlet (6) is connected with an actuator; in the embodiment, taking a digital valve group (1) with four valves connected in parallel as an example, each valve may have 5 types of valve core faults, such as no opening, no closing, no complete opening, no complete closing and jamming; in the event of a single valve failure, there areA seed fault flow model; in the event of failure of both valves, there isA seed fault flow model; in the event of failure of three valves, there areA seed fault flow model; in the event of failure of four valves, there areThe fault flow model and the normal flow mathematical model of all valves are provided. Thus, there are 1296 flow patterns for four valves, each using PCM control signals (i.e., 0-off, 1-on), with 16 combinations of switching signals for all four valves, and encoding (0-15) all combinations of control signals for 4 valves, where the encoded signals correspond one-to-one to the binary control signals for the four valves; when the coded signal is switched once, the sum of the actual output flows of the four valves is compared with the output flows of the 1296 mathematical models under the current control signal, the deviation is obtained through calculation, the absolute value of the deviation is stored in an accumulator, and the absolute value is accumulated on the original deviation for a plurality of times along with the change of the control signal. And comparing the accumulated deviation values to obtain a fault model corresponding to the minimum value, namely diagnosing the type, the number and the position of the fault valve.
In this embodiment, as shown in fig. 2, the digital valve group multi-fault diagnosis method includes: control signal coding, fault model base comparison, deviation accumulation and minimum value judgment; the method comprises the following specific steps:
signal input: the input signals comprise a control signal U and a differential pressure signal delta p acquired by pressure sensors arranged in front of and behind the valve bank. Wherein, UiIs a four-dimensional column vector representing the control signals of the four digital valves at the ith moment;
signal coding: control signal vector UiThe binary signal in the control vector is converted into decimal value which is the signal code u of the control vector at the momentiThe change of the signal code is used for making a trigger condition of difference and accumulation;
Comparing a fault model library: firstly, a mathematical model library comprises 1296 flow models, wherein each valve has five fault states of no opening, no closing, no complete opening, no complete closing and blocking independently, any fault combination state of any number of valves and normal states of all valves; under the 1296 models, the normal valve group flow is Q1(Ui) 1 when the valve is not opened, the flow of the valve group is Q2(Ui) And 2, when the valve is not opened, the flow of the valve group is Q3(Ui) And 3 when the valve is not opened, the flow of the valve group is Q4(Ui) And 4 when the valve is not opened, the flow of the valve group is Q5(Ui) (ii) a 1 when the valve is not closed, the flow of the valve group is Q6(Ui) And 2, when the valve is not closed, the flow of the valve group is Q7(Ui) And when the valve is not closed, the flow of the valve group is Q8(Ui) And 4, when the valve is not closed, the flow of the valve group is Q9(Ui) (ii) a 1 valve group flow rate is Q when valve can not be opened completely10(Ui) And when the valve 2 can not be completely opened, the flow rate of the valve group is Q11(Ui) And when the valve 3 can not be completely opened, the flow rate of the valve group is Q12(Ui) And when the 4-valve can not be completely opened, the flow rate of the valve group is Q13(Ui) (ii) a 1 valve isWhen the valve group can be completely closed, the flow rate of the valve group is Q14(Ui) And when the valve 2 can not be completely closed, the flow of the valve group is Q15(Ui) And when the valve 3 can not be completely closed, the valve group flow is Q16(Ui) And when the 4-valve can not be completely closed, the valve group flow is Q17(Ui) (ii) a 1 valve clamping dead time valve group flow is Q18(Ui) And 2, when the valve is blocked, the flow of the valve group is Q19(Ui) And 3, the flow of the valve group is Q when the valve is blocked20(Ui) And 4, the flow of the valve group is Q when the valve is blocked21(Ui) (ii) a The flow rate of the valve 1 not opened and the valve 2 not opened is Q22(Ui) The flow rate of the 1 valve which cannot be opened and the 2 valve which cannot be closed is Q23(Ui) … …, flow rate Q with 3 valves stuck and 4 valves stuck171(Ui) (ii) a The flow rate of the valve 1, the valve 2 and the valve 3 which can not be opened is Q172(Ui) … …, 2 valve 3 valve 4 valve dead flow rate is Q671(Ui) (ii) a The flow rate of the non-opening valves 1, 2, 3 and 4 is Q672(Ui) … …, flow rate Q when valve 1, valve 2, valve 3, and valve 4 are stuck1296(Ui);
The actual flow Q of the digital valve group is equal to the current control signal U when the signal code changes oncei1296 model flows Q under differential pressure delta p1(Ui),…,Q1296(Ui) Respectively carrying out difference and obtaining absolute values to obtain deviation e1n,…,e1296n;
And (3) deviation accumulation: accumulating the deviation of each flow model under the current condition once every time the signal code changes to obtain deviation sum E1,…,E1296Representing the degree of deviation of the actual flow from the 1296 flow models;
and (3) minimum value judgment: comparing E over a period of time1,…,E1296To obtain the minimum value ExAnd (4) explaining that the current state is closest to the x-th state, namely judging the type, the number and the position of the fault valve.
The above-mentioned embodiments are merely illustrative of the preferred embodiments of the present invention, and do not limit the scope of the present invention, and various modifications and improvements of the technical solution of the present invention by those skilled in the art without departing from the spirit of the present invention should fall within the protection scope defined by the appended claims.
Claims (6)
1. A digital valve pack multiple fault detection device, comprising: the digital valve bank (1), the control system module (7), the pressure sensor (3), the flow sensor (4), the pressure source (5) and the oil outlet (6) are connected in parallel through the control circuit (2);
the digital valve group (1) is mainly formed by connecting four switch valves with the same flow grade, a controller, a flow sensor and a pressure sensor in parallel;
the pressure source (5) is mainly provided with a hydraulic pump connected with an oil tank;
the end of the oil outlet (6) is connected with an actuator;
the control system module (7) mainly comprises an acquisition card, an upper computer, an adjustable direct-current power supply, a small-flow electromagnetic switch valve, a pressure sensor (3) and a flow sensor (4), wherein a first end of the adjustable direct-current power supply is electrically connected with a control end of the acquisition card, a second end of the adjustable direct-current power supply is electrically connected with a power end of a coil of the small-flow electromagnetic switch valve, the flow sensor (4) is connected with an outlet of a digital valve group (1) in series, the pressure sensor (3) is electrically connected with an outlet and an inlet of the digital valve group (1), an acquisition end of the acquisition card is electrically connected with output ends of the flow sensor (4) and the pressure sensor (3), and an output end of the acquisition card is electrically connected with the upper computer through a wire cable.
2. A digital valve group multi-fault diagnosis method is characterized by comprising the following steps: inputting signals, coding the signals, comparing a fault model library, accumulating deviations and judging the minimum value;
signal input: the input signals mainly comprise a control signal U and a differential pressure signal delta p acquired by pressure sensors (3) in front of and behind the digital valve bank (1); wherein, UiIs a four-dimensional column vector representing the control signals of the four digital valves at the ith moment;
signal coding: control signal vector UiThe binary signal in (1) is converted into a decimal value, namely the signal code ui of the control vector at the moment,the change of the signal codes is used for making triggering conditions of difference and accumulation;
comparing a fault model library: each valve independently generates five fault states of no opening, no closing, no complete opening, no complete closing and blocking, a combined state of any fault of any number of valves and a state of all valves being normal; the actual flow Q of the digital valve group and the current control signal U are obtained when the signal code changes oncei1296 model flows Q under differential pressure delta p1(Ui),…,Q21(Ui) Respectively carrying out difference and obtaining absolute values to obtain deviation e1n,…,e1296n;
And (3) deviation accumulation: when the signal code changes once, the deviation of each flow model under the current condition is accumulated once to obtain the deviation sum E1,…,E1296Representing the degree of deviation of the actual flow from the 1296 flow models;
and (3) minimum value judgment: comparing E over a period of time1,…,E1296To obtain the minimum value ExAnd (4) explaining that the current state is closest to the x-th state, namely, the position, the number and the fault type of the fault valve can be judged.
3. The digital valve group multiple fault diagnosis method according to claim 2, characterized in that: and (3) modeling all faults of all digital valves, and comparing the difference sum of the actual flow and the model flow in a period of time to judge the fault type.
4. The digital valve group multiple fault diagnosis method according to claim 2, characterized in that: there is no requirement for control signals and no connection between signals, and in addition, the diagnostic method has no requirement for pressure, i.e. is suitable for various operating conditions.
5. The digital valve group multiple fault diagnosis method according to claim 2, characterized in that: the difference between the actual flow of the valve group and the model flow in a period of time can be compared to judge that any valve or valve cores of the valves can not be opened, closed or clamped in the middle, can not be opened completely, can not be closed completely and can be in normal six states.
6. The digital valve group multiple fault diagnosis method according to claim 2, characterized in that: the method can be used for simultaneously solving the problem that a plurality of valves have faults, and the positions, the number and the fault types of the fault valves can be judged.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN202110859572.5A CN113607405B (en) | 2021-07-28 | 2021-07-28 | Digital valve group multi-fault detection device and diagnosis method thereof |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN202110859572.5A CN113607405B (en) | 2021-07-28 | 2021-07-28 | Digital valve group multi-fault detection device and diagnosis method thereof |
Publications (2)
Publication Number | Publication Date |
---|---|
CN113607405A true CN113607405A (en) | 2021-11-05 |
CN113607405B CN113607405B (en) | 2022-07-29 |
Family
ID=78305823
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CN202110859572.5A Active CN113607405B (en) | 2021-07-28 | 2021-07-28 | Digital valve group multi-fault detection device and diagnosis method thereof |
Country Status (1)
Country | Link |
---|---|
CN (1) | CN113607405B (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN114509933A (en) * | 2022-01-12 | 2022-05-17 | 燕山大学 | Uniform switching control method for digital valve bank |
CN114526273A (en) * | 2022-01-10 | 2022-05-24 | 哈尔滨理工大学 | Multifunctional intelligent hydraulic digital valve |
Citations (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20030008187A1 (en) * | 2001-07-04 | 2003-01-09 | Kazutoshi Higashiyama | Hydrogen producing apparatus and power generating system using it |
CN102865451A (en) * | 2011-07-04 | 2013-01-09 | 美卓造纸机械公司 | Safety component |
CN104049627A (en) * | 2013-03-14 | 2014-09-17 | 费希尔控制国际公司 | Valve prognostics for polymeric components based on accelerated aging techniques |
CN104074840A (en) * | 2014-07-16 | 2014-10-01 | 上海豪高机电科技有限公司 | Digital valve testing system |
US20160299512A1 (en) * | 2015-04-10 | 2016-10-13 | Goodrich Corporation | Electro-hydraulic servo valve control system |
CN109441904A (en) * | 2018-12-26 | 2019-03-08 | 燕山大学 | A kind of digital valve pack PWM and PCM composite control apparatus apparatus control method |
CN112698642A (en) * | 2021-01-19 | 2021-04-23 | 燕山大学 | Fault diagnosis method of digital valve bank based on PCM control |
US20210180536A1 (en) * | 2018-07-13 | 2021-06-17 | Vitesco Technologies GmbH | Method for diagnosing a digital flow-control valve of a high-pressure fuel injection pump |
CN113124009A (en) * | 2021-04-30 | 2021-07-16 | 中国重型机械研究院股份公司 | Load port flow pulse independent control digital hydraulic servo system and control method |
-
2021
- 2021-07-28 CN CN202110859572.5A patent/CN113607405B/en active Active
Patent Citations (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20030008187A1 (en) * | 2001-07-04 | 2003-01-09 | Kazutoshi Higashiyama | Hydrogen producing apparatus and power generating system using it |
CN102865451A (en) * | 2011-07-04 | 2013-01-09 | 美卓造纸机械公司 | Safety component |
CN104049627A (en) * | 2013-03-14 | 2014-09-17 | 费希尔控制国际公司 | Valve prognostics for polymeric components based on accelerated aging techniques |
CN104074840A (en) * | 2014-07-16 | 2014-10-01 | 上海豪高机电科技有限公司 | Digital valve testing system |
US20160299512A1 (en) * | 2015-04-10 | 2016-10-13 | Goodrich Corporation | Electro-hydraulic servo valve control system |
US20210180536A1 (en) * | 2018-07-13 | 2021-06-17 | Vitesco Technologies GmbH | Method for diagnosing a digital flow-control valve of a high-pressure fuel injection pump |
CN109441904A (en) * | 2018-12-26 | 2019-03-08 | 燕山大学 | A kind of digital valve pack PWM and PCM composite control apparatus apparatus control method |
CN112698642A (en) * | 2021-01-19 | 2021-04-23 | 燕山大学 | Fault diagnosis method of digital valve bank based on PCM control |
CN113124009A (en) * | 2021-04-30 | 2021-07-16 | 中国重型机械研究院股份公司 | Load port flow pulse independent control digital hydraulic servo system and control method |
Non-Patent Citations (1)
Title |
---|
左平: "工业4.0时代下利用数字技术的阀门在线诊断趋势与实现", 《仪器仪表用户》 * |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN114526273A (en) * | 2022-01-10 | 2022-05-24 | 哈尔滨理工大学 | Multifunctional intelligent hydraulic digital valve |
CN114509933A (en) * | 2022-01-12 | 2022-05-17 | 燕山大学 | Uniform switching control method for digital valve bank |
CN114509933B (en) * | 2022-01-12 | 2024-04-12 | 燕山大学 | Uniform switching control method for digital valve group |
Also Published As
Publication number | Publication date |
---|---|
CN113607405B (en) | 2022-07-29 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
CN113607405B (en) | Digital valve group multi-fault detection device and diagnosis method thereof | |
CN112698642B (en) | Fault diagnosis method of digital valve bank based on PCM control | |
CN110118128B (en) | Fault diagnosis and fault-tolerant control method for micro gas turbine sensor | |
CN100437408C (en) | Flow control system and control method in mixed mode of pulse code modulation and pulse width modulation | |
US4667284A (en) | Multiplexing control unit | |
CN113011248B (en) | Nuclear power plant fault diagnosis method based on LSTM | |
CN113700558B (en) | Diesel engine air system fault detection method | |
CN110263837A (en) | A kind of circuit breaker failure diagnostic method based on multilayer DBN model | |
CN113485863B (en) | Method for generating heterogeneous imbalance fault samples based on improved generation of countermeasure network | |
CN112014687A (en) | Layered positioning method for fault section of active power distribution network containing distributed power supply | |
CN115750228A (en) | Fault early warning method for pitch system of wind turbine generator | |
CN115578084A (en) | Wind turbine generator set frequency converter fault early warning method based on deep convolution self-encoder | |
Cheng et al. | A research about pattern recognition of control chart using probability neural network | |
CN101210859A (en) | Hypersonic intake duct starting/ non-starting mode integrated classification and determination method | |
CN114089118A (en) | Intelligent substation fault positioning method based on gated cyclic unit network | |
CN109583779B (en) | Method for determining weak element of electric-gas interconnection system | |
CN111272222A (en) | Transformer fault diagnosis method based on characteristic quantity set | |
CN115808209A (en) | Neural network-based state monitoring method and system for electro-static pressure servo mechanism | |
CN110854826B (en) | Fault diagnosis and processing method for two-out-of-three protection system of flexible direct converter valve | |
CN212318211U (en) | Digital speed regulating system of water turbine of low-voltage generator set | |
CN112749789A (en) | Aero-engine multiple fault diagnosis device based on self-association neural network | |
CN112347640B (en) | Fault diagnosis method based on fixed time fault observer | |
Lee et al. | Sensor value validation based on implicit sensor redundancy for reliable operation of power plants | |
Kang et al. | Research on Fault Diagnosis of Power Communication Network Based on Improved Convolutional Neural Network | |
CN109510628A (en) | The recognition by pressing keys method of key circuit, matrix press-key circuit and matrix press-key circuit |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
PB01 | Publication | ||
PB01 | Publication | ||
SE01 | Entry into force of request for substantive examination | ||
SE01 | Entry into force of request for substantive examination | ||
GR01 | Patent grant | ||
GR01 | Patent grant |