CN114499057B - Magnetic interference elimination method for brushless direct current motor - Google Patents
Magnetic interference elimination method for brushless direct current motor Download PDFInfo
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- CN114499057B CN114499057B CN202210248214.5A CN202210248214A CN114499057B CN 114499057 B CN114499057 B CN 114499057B CN 202210248214 A CN202210248214 A CN 202210248214A CN 114499057 B CN114499057 B CN 114499057B
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- 238000000354 decomposition reaction Methods 0.000 claims description 8
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02K—DYNAMO-ELECTRIC MACHINES
- H02K11/00—Structural association of dynamo-electric machines with electric components or with devices for shielding, monitoring or protection
- H02K11/02—Structural association of dynamo-electric machines with electric components or with devices for shielding, monitoring or protection for suppression of electromagnetic interference
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- G—PHYSICS
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- G06T3/00—Geometric image transformations in the plane of the image
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- G06T3/4007—Scaling of whole images or parts thereof, e.g. expanding or contracting based on interpolation, e.g. bilinear interpolation
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- G—PHYSICS
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- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F2218/00—Aspects of pattern recognition specially adapted for signal processing
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- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
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Abstract
The invention discloses a magnetic interference elimination method of a brushless direct current motor. The method can effectively eliminate the interference of the brushless direct current motor on the magnetometer receiving signals, and improves the detection accuracy of the magnetometer.
Description
Technical Field
The invention relates to the field of signal magnetic elimination, in particular to a magnetic interference elimination method of a brushless direct current motor.
Background
Brushless dc motors can interfere with magnetometers operating therearound during operation. Previous studies have mostly focused on adding shields to or optimizing the structure of a brushless dc motor to reduce magnetic interference, such as patent grant nos. CN210927364U, CN208143025U, but this approach requires modification or replacement of existing structures. Some researches also propose algorithms to eliminate magnetic interference, but the algorithms have high complexity and are not suitable for a real-time system.
The detection of the submarine cable has very important roles in maintaining and repairing the submarine cable and ensuring the communication and power transmission. The detection, maintenance and repair of subsea cables is typically based on a remotely controlled unmanned submersible (remotely operated vehicle, ROV) platform. The signals acquired by the ROV-mounted magnetometer are an important basis for magnetically probing subsea cables. In recent years, as ROVs have been increased in size and in electric power, the efficiency of maintaining subsea cables has been increasing. However, the magnetic field generated during operation of the brushless dc motor can severely interfere with the signals of the ROV-mounted magnetometer, thereby greatly reducing the accuracy of detecting subsea cables with the magnetometer. Furthermore, other tasks requiring the use of magnetometers, such as detection of the earth's magnetic field, detection of unexplosive bombs (unexploded ordnance, UXO) on the seafloor, are affected.
It is therefore necessary to eliminate the magnetometer disturbances caused by the brushless dc motor. The invention mainly researches the interference characteristic of the motor magnetic field, proposes the relation between the magnetic interference frequency and the motor rotating speed, and accordingly proposes a feasible method to inhibit the influence of interference on magnetometer signals and improve the accuracy of submarine cable positioning by using magnetometers.
Disclosure of Invention
Aiming at the defects of the prior art, the invention provides a brushless direct current motor magnetic interference elimination method which can ensure that the accuracy of magnetometer detection is improved and the algorithm complexity is low.
The aim of the invention is achieved by the following technical scheme:
a method for eliminating magnetic interference of brushless DC motor, which eliminates interference by using relation between rotation speed and magnetic interference frequency of brushless DC motor, includes the following steps:
s1: acquiring a magnetometer original signal with brushless direct current motor magnetic interference;
s2: filtering the original signal of the magnetometer with the brushless direct current motor magnetic interference;
s3: obtaining the envelope surface s of the filtered signal Env ；
S4: collecting the rotating speed of a brushless direct current motor which is the same as the starting and stopping time period of the original signal of the magnetometer;
s5: according to the relation between the rotating speed of the brushless direct current motor and the magnetic interference frequency, calculating n of the rotating speed of the brushless direct current motor, setting a speed interval including n, and setting a signal s of the brushless direct current motor in a time period corresponding to the speed interval Env Discarding;
the relation between the rotating speed of the brushless direct current motor and the magnetic interference frequency is as follows:
wherein p is the number of pole pairs of the brushless direct current motor, n is the rotating speed of the brushless direct current motor, the unit is RPM, and f is the frequency of magnetic interference generated by the brushless direct current motor, and the unit is Hz;
s6: filling the signal interval discarded in the step S5 by adopting an interpolation method to obtain a signal S IC ；
S7: for signal s IC Smoothing to obtain signal s without magnetic interference final 。
Further, the interpolation method in S6 is a linear interpolation.
Further, in S7, a wavelet method is used for the signal S IC Smoothing is performed.
Further, in the step S5, when the calculated n of the rotation speed of the brushless dc motor is less than 1000rpm, the deviation between the upper and lower thresholds of the speed interval and n is 20% -50%; when the calculated n of the rotating speed of the brushless direct current motor is more than or equal to 1000rpm, the deviation between the upper and lower thresholds of the speed interval and n is 5% -50%.
Further, the method utilizes wavelet method to process the signal s IC The specific steps of smoothing are as follows:
(1) Selecting the number L of layers of wavelet decomposition and the type of the decomposition wavelet;
(2) Calculating the signal s IC Wavelet decomposition at layer L;
(3) Calculating a threshold value of each of the first layer to the L-th layer;
(4) And processing the detail coefficient by a soft threshold value application method;
(5) Calculating a signal s free of magnetic interference from thresholding detail coefficients of the order from 1 to L final 。
The beneficial effects of the invention are as follows:
(1) The method for eliminating the magnetic interference of the brushless direct current motor provides the relation between the rotating speed of the brushless direct current motor and the magnetic interference frequency, and can provide reference for the later invention.
(2) The method for eliminating the magnetic interference of the brushless direct current motor can effectively eliminate the influence of the brushless direct current motor on the magnetometer.
(3) The method for eliminating the magnetic interference of the brushless direct current motor has low algorithm complexity and small burden on a system.
(4) The magnetic interference elimination method of the brushless direct current motor is suitable for underwater ROV magnetic detection, and improves the detection accuracy.
Drawings
Fig. 1 is a flow chart of the method.
Fig. 2 shows the effect of single channel interference cancellation.
FIG. 3 is a graph showing signal comparisons at different processing stages.
Fig. 4 is a comparison chart of positioning effects before and after signal interference cancellation.
Detailed Description
The objects and effects of the present invention will become more apparent from the following detailed description of the preferred embodiments and the accompanying drawings, it being understood that the specific embodiments described herein are merely illustrative of the invention and not limiting thereof.
As shown in fig. 1, the method for eliminating magnetic interference of the brushless direct current motor of the invention specifically comprises the following steps:
s1: acquiring a magnetometer original signal with brushless direct current motor magnetic interference;
s2: filtering the original signal of the magnetometer with the brushless direct current motor magnetic interference;
s3: obtaining the envelope surface s of the filtered signal Env ；
S4: collecting the rotating speed of a brushless direct current motor which is the same as the starting and stopping time period of the original signal of the magnetometer;
s5: according to the relation between the rotating speed of the brushless direct current motor and the magnetic interference frequency, calculating n of the rotating speed of the brushless direct current motor, setting a speed interval including n, and when the rotating speed of the motor reaches the speed, setting a signal s of the brushless direct current motor in a time period corresponding to the speed interval Env Discarding.
The specific deduction of the relation between the rotating speed of the brushless direct current motor and the magnetic interference frequency is as follows:
the brushless DC motor is composed of a stator, a rotor and a commutator, when the rotor rotates in a main magnetic field generated by the stator, an armature winding on the rotor can cut a magnetic induction line to generate electromotive force, the generated electromotive force causes current fluctuation, and the current fluctuation forms a leakage magnetic field outwards through an antenna effect of an electric wire outside the motor. This leakage field is the external magnetic disturbance for the magnetometer. The frequency of the leakage magnetic field is related to the rotation speed of the motor, if the number of the pole pairs of the motor is m, when the rotation speed is constant, the operation condition of each group of pole pairs is the same, and can be regarded as one period, and the outward radiated magnetic field is the same, so that the corresponding relationship between the frequency of the outward radiated leakage magnetic field and the rotation speed of the brushless direct current motor is as follows:
wherein p is the number of pole pairs of the brushless direct current motor, n is the rotating speed of the brushless direct current motor, the unit is RPM, and f is the frequency of magnetic interference generated by the brushless direct current motor, and the unit is Hz.
S6: filling the signal interval discarded in the step S5 by adopting an interpolation method to obtain a signal S IC . The interpolation method is preferably linear difference, is simple and convenient to operate and has small calculated amount.
S7: for signal s IC Smoothing to obtain signal s without magnetic interference final . Smoothing the signal may be performed by various methods, preferably by wavelet methods, which are used to smooth the signal s IC The specific steps of smoothing are as follows:
(1) Selecting the number L of layers of wavelet decomposition and the type of the decomposition wavelet;
(2) Calculating the signal s IC Wavelet decomposition at layer L;
(3) Calculating a threshold value of each of the first layer to the L-th layer;
(4) And processing the detail coefficient by a soft threshold value application method;
(5) Calculating a signal s free of magnetic interference from thresholding detail coefficients of the order from 1 to L final 。
The method for eliminating the magnetic interference of the brushless direct current motor is particularly applied to detection of submarine cables. In the underwater scene, the original signal is obtained by introducing current with any frequency of 0-50 Hz into the submarine cable and obtaining the original signal in the motion process by the ROV carrying the magnetometer.
In this embodiment, 25Hz current is supplied to the submarine cable, and a large-scale electric ROV-mounted magnetometer detects a magnetic signal emitted from the submarine cable, and the acquired magnetic signal must include time information for alignment with time data included in the rotational speed v of the brushless dc motor. The acquired magnetometer signals are filtered using a bandpass filter. The center frequency of the band pass filter was 25Hz and the pass band width was 2Hz. Then carrying out envelope detection on the filtered signal to obtain an envelope signal s Env 。s Env Including time data. The rotating speed of the brushless direct current motor is obtained by a rotating speed v sensor of the brushless direct current motor and comprises time data。
The position information of the submarine cable in the magnetometer, i.e. the magnetic signal frequency of the submarine cable, is 25Hz. According to formula (1), the corresponding brushless DC motor speed is 300RPM. Thus the speed bandwidth is set to 200RPM-400RPM, when the speed is within this range, signal s Env The part of the corresponding time period is discarded, and the gap is filled by a linear interpolation method. The signal after interference cancellation is signal s IC . The interference cancellation effect is shown in fig. 2.
In this embodiment, the signal s is processed by wavelet method IC Smoothing is performed and the selected wavelet is sym4 wavelet in Symlet, decomposing the signal to level 12. Signal pairs for different processing stages are shown in fig. 3. The signal positioning effect after the interference cancellation is shown in fig. 4. By using the brushless direct current motor interference elimination method, the magnetometer positioning error is reduced by more than 80%.
It will be appreciated by persons skilled in the art that the foregoing description is a preferred embodiment of the invention, and is not intended to limit the invention, but rather to limit the invention to the specific embodiments described, and that modifications may be made to the technical solutions described in the foregoing embodiments, or equivalents may be substituted for elements thereof, for the purposes of those skilled in the art. Modifications, equivalents, and alternatives falling within the spirit and principles of the invention are intended to be included within the scope of the invention.
Claims (5)
1. A method for eliminating magnetic interference of a brushless DC motor is characterized in that the relation between the rotating speed of the brushless DC motor and the magnetic interference frequency is utilized to eliminate the interference, and the method comprises the following steps:
s1: acquiring a magnetometer original signal with brushless direct current motor magnetic interference;
s2: filtering the original signal of the magnetometer with the brushless direct current motor magnetic interference;
s3: obtaining the envelope surface of the filtered signals Env ；
S4: collecting the rotating speed of a brushless direct current motor which is the same as the starting and stopping time period of the original signal of the magnetometer;
s5: according to the relation between the rotating speed of the brushless direct current motor and the magnetic interference frequency, calculating to obtain the rotating speed of the brushless direct current motornAnd is provided withnA speed interval, a signal of the brushless DC motor in a corresponding time period of the speed intervals Env Discarding;
the relation between the rotating speed of the brushless direct current motor and the magnetic interference frequency is as follows:
f =n×p/60
wherein ,pis the number of pole pairs of the brushless DC motor,nis the rotating speed of the brushless direct current motor, the unit is RPM,fthe frequency of magnetic interference generated by the brushless direct current motor is expressed in Hz;
s6: filling the signal interval discarded in the step S5 by adopting an interpolation method to obtain a signals IC ；
S7: for signalss IC Smoothing to obtain signal without magnetic interferences final 。
2. The method for eliminating magnetic interference of a brushless dc motor according to claim 1, wherein the interpolation method in S6 is linear interpolation.
3. The method for eliminating magnetic interference of brushless direct current motor according to claim 1, wherein in S7, a wavelet method is used for signals IC Smoothing is performed.
4. The method as claimed in claim 1, wherein in S5, when the calculated rotation speed of the brushless dc motor isnAt less than 1000rpm, the upper and lower thresholds of the speed interval are equal tonThe deviation of (2) is 20% -50%; when the calculated rotation speed of the brushless DC motor isnWhen the speed is more than or equal to 1000rpm, the upper and lower thresholds of the speed interval are equal tonThe deviation of (2) is 5% -50%.
5. A brushless according to claim 3The method for eliminating the magnetic interference of the direct current motor is characterized by comprising the following steps of: the wavelet method is adopted for the signals IC The specific steps of smoothing are as follows:
(1) Selecting the number of layers of wavelet decompositionLDecomposing the type of wavelet;
(2) Calculating a signals IC In the first placeLWavelet decomposition of the layer;
(3) Calculate from the first layer to the first layerLA threshold for each of the layers;
(4) And processing the detail coefficient by a soft threshold value application method;
(5) According to from 1 toLThreshold processing detail coefficient calculation of level(s) of (a) for signals without magnetic interferences final 。
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Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2008306906A (en) * | 2007-06-11 | 2008-12-18 | Fujitsu General Ltd | Control method of and controller of brushless dc motor |
| CN106712594A (en) * | 2015-07-14 | 2017-05-24 | 李永诚 | Motor driver of motor control system |
| CN110303521A (en) * | 2018-03-27 | 2019-10-08 | 清华大学 | Joint of robot torque signals acquisition system and method |
| CN112036435A (en) * | 2020-07-22 | 2020-12-04 | 温州大学 | Brushless direct current motor sensor fault detection method based on convolutional neural network |
| CN112858906A (en) * | 2021-01-05 | 2021-05-28 | 中国神华能源股份有限公司国华电力分公司 | Method for eliminating influence of motor rotation speed disturbance on fatigue accumulation |
| US11204609B1 (en) * | 2019-06-25 | 2021-12-21 | Amazon Technologies, Inc. | Active braking system for an autonomous mobile device |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100910857B1 (en) * | 2002-10-29 | 2009-08-06 | 페어차일드코리아반도체 주식회사 | Method and apparatus for reducing electromagnetic interference |
| JP6429453B2 (en) * | 2013-11-26 | 2018-11-28 | キヤノン株式会社 | Motor control apparatus and image forming apparatus |
| CN107614121B (en) * | 2015-06-01 | 2019-10-25 | 深圳市大疆创新科技有限公司 | The sprinkling system of feedback with fluid flow and revolving speed |
| CN109522802B (en) * | 2018-10-17 | 2022-05-24 | 浙江大学 | Pump noise elimination method applying empirical mode decomposition and particle swarm optimization algorithm |
-
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- 2022-03-14 CN CN202210248214.5A patent/CN114499057B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2008306906A (en) * | 2007-06-11 | 2008-12-18 | Fujitsu General Ltd | Control method of and controller of brushless dc motor |
| CN106712594A (en) * | 2015-07-14 | 2017-05-24 | 李永诚 | Motor driver of motor control system |
| CN110303521A (en) * | 2018-03-27 | 2019-10-08 | 清华大学 | Joint of robot torque signals acquisition system and method |
| US11204609B1 (en) * | 2019-06-25 | 2021-12-21 | Amazon Technologies, Inc. | Active braking system for an autonomous mobile device |
| CN112036435A (en) * | 2020-07-22 | 2020-12-04 | 温州大学 | Brushless direct current motor sensor fault detection method based on convolutional neural network |
| CN112858906A (en) * | 2021-01-05 | 2021-05-28 | 中国神华能源股份有限公司国华电力分公司 | Method for eliminating influence of motor rotation speed disturbance on fatigue accumulation |
Non-Patent Citations (5)
| Title |
|---|
| Adaptive Dynamic Programming Based on Parallel Control Theory for Underwater Vehicles;Peng Bo等;2021 IEEE 1st International Conference on Digital Twins and Parallel Intelligence (DTPI);54-57 * |
| 基于小波变换的无刷直流电动机逆变器故障检测仿真研究;贺昌权;包广清;;微电机(01);74-77 * |
| 基于小波网络的永磁无刷直流电机无位置传感器控制;史婷娜;田洋;夏长亮;;天津大学学报(02);190-194 * |
| 基于小波降噪和形态补偿的抗电磁干扰方法;杨云涛;石志勇;关贞珍;许杨;;火力与指挥控制(02);101-103 * |
| 超导量子磁力仪在海底光缆探测定位中的应用;周学军;张扬;姚琦;周媛媛;左名久;;海军工程大学学报(05);71-75 * |
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