阅读说明：本技术 一种磁场感应测量系统、方法、控制装置及存储介质 (Magnetic field induction measuring system, method, control device and storage medium ) 是由 朱惠君 薛鹏 白金刚 毛志松 邬耀华 于 2020-06-22 设计创作，主要内容包括：本发明公开的一种磁场感应测量系统、方法、控制装置及存储介质,包括：控制模块、光源、环形器、磁场感应装置和解调仪,环形器包括第一端、第二端和第三端,光源与环形器的第一端连接,磁场感应装置与环形器的第二端连接,解调仪的输入端与环形器的第三端连接,磁场感应装置包括至少一个传感单元,传感单元包括电磁敏感模块以及设置在电磁敏感模块上的设置有光纤编码的光纤,解调仪和光源分别与控制模块连接,通过基于光纤编码技术测量的电磁能量值不受干扰,能够防止出现测量干扰的问题,提高测量结果的准确度。(The invention discloses a magnetic field induction measuring system, a magnetic field induction measuring method, a magnetic field induction measuring control device and a storage medium, wherein the magnetic field induction measuring system comprises the following components: control module, the light source, the circulator, magnetic field induction system and demodulation appearance, the circulator includes first end, second end and third end, the light source is connected with the first end of circulator, magnetic field induction system is connected with the second end of circulator, the input of demodulation appearance is connected with the third end of circulator, magnetic field induction system includes at least one sensing unit, sensing unit includes the electromagnetic sensitive module and sets up the optic fibre that is provided with the optic fibre code on the electromagnetic sensitive module, demodulation appearance and light source are connected with control module respectively, do not receive the interference through the electromagnetic energy value based on the measurement of optic fibre coding technique, can prevent to appear the problem of measuring the interference, improve the degree of accuracy of measuring result.)

1. A magnetic field induction measurement system, comprising: the circulator comprises a first end, a second end and a third end, the light source is connected with the first end of the circulator, the magnetic field sensing device is connected with the second end of the circulator, the input end of the demodulator is connected with the third end of the circulator, the magnetic field sensing device comprises at least one sensing unit, the sensing unit comprises an electromagnetic sensing module and an optical fiber arranged on the electromagnetic sensing module and provided with an optical fiber code, and the demodulator and the light source are respectively connected with the control module.

2. A magnetic field induction measuring system according to claim 1, characterized in that said magnetic field induction means comprises at least two of said sensing units connected by optical fibers.

3. A magnetic field induction measuring system according to claim 2, characterized in that each two connected sensing units are U-shaped.

4. A magnetic field induction measuring system according to claim 1, wherein the orthographic projection of the fibre-optic code onto the electromagnetic susceptibility module falls within the electromagnetic susceptibility module.

5. A magnetic field induction measuring system according to claim 1, characterized in that said electromagnetic sensitive module is a rare earth alloy plate.

6. A magnetic field induction measuring system according to claim 5, characterized in that said rare earth alloy plate is bonded to said optical fiber provided with an optical fiber code.

7. A magnetic field induction measuring method is characterized by being applied to a magnetic field induction measuring system, and the magnetic field induction measuring system comprises the following components: the circulator comprises a first end, a second end and a third end, the light source is connected with the first end of the circulator, the magnetic field sensing device is connected with the second end of the circulator, the input end of the demodulator is connected with the third end of the circulator, the magnetic field sensing device comprises at least one sensing unit, the sensing unit comprises an electromagnetic sensing module and an optical fiber which is arranged on the electromagnetic sensing module and provided with an optical fiber code, and the demodulator and the light source are respectively connected with the control module;

the magnetic field induction measuring method comprises the following steps:

the control module controls the light source to output light waves;

the control module controls the demodulator to detect reflected light of the light wave reflected by the optical fiber code in the magnetic field sensing device to obtain the current wavelength value of the optical fiber grating in the optical fiber code;

the control module obtains a wavelength change value according to the current wavelength value and the initial wavelength value;

and the control module obtains a corresponding electromagnetic energy value according to the wavelength change value.

8. The magnetic field induction measuring method according to claim 7, wherein the magnetic field induction device comprises at least two sensing units connected by optical fibers, each two connected sensing units are arranged in a U shape, and all the optical fiber coding matrixes in the at least two sensing units are arranged;

the control module further comprises the following steps after obtaining the corresponding electromagnetic energy value according to the energy change value:

and the control module forms the electromagnetic energy value corresponding to the wavelength change value of the fiber grating in each optical fiber code into an electromagnetic energy value matrix array according to the position corresponding information of the optical fiber code on the magnetic field induction device to obtain an electromagnetic field distribution pattern and an electromagnetic energy change pattern.

9. A measurement control apparatus comprising: memory, a control processor and a computer program stored on the memory and executable on the control processor, characterized in that the control processor implements the magnetic field induction measurement method according to any one of claims 7 to 8 when executing the computer program.

10. Computer-readable storage medium, characterized in that it stores computer-executable instructions for causing a computer to perform the magnetic field induction measurement method according to any one of claims 7 to 8.

Technical Field

The invention relates to the field of optical fibers, in particular to a magnetic field induction measuring system, a magnetic field induction measuring method, a magnetic field induction measuring control device and a storage medium.

Background

At present, the conventional electromagnetic field induction adopts an electronic radar mode for measurement, and the measurement mode is easily interfered, so that the measurement result is inaccurate.

Disclosure of Invention

In order to solve the above problems, an object of the present invention is to provide a magnetic field induction measurement system, a magnetic field induction measurement method, a magnetic field induction measurement control device, and a storage medium, which can prevent the occurrence of measurement interference and improve the accuracy of measurement results.

The technical scheme adopted by the invention for solving the problems is as follows:

in a first aspect, an embodiment of the present invention provides a magnetic field induction measurement system, including: the circulator comprises a first end, a second end and a third end, the light source is connected with the first end of the circulator, the magnetic field sensing device is connected with the second end of the circulator, the input end of the demodulator is connected with the third end of the circulator, the magnetic field sensing device comprises at least one sensing unit, the sensing unit comprises an electromagnetic sensing module and an optical fiber arranged on the electromagnetic sensing module and provided with an optical fiber code, and the demodulator and the light source are respectively connected with the control module.

The technical scheme of the invention at least has one of the following advantages or beneficial effects: the electromagnetic sensitive module is arranged on the optical fiber provided with the optical fiber code, the electromagnetic sensitive module can deform under the action of an electromagnetic field, the deformation of the electromagnetic sensitive module can deform the optical fiber code in the optical fiber, so that the wavelength of the optical fiber code is changed, the control module can control the light source to be turned on and off, the optical fiber code in the optical fiber is identified and detected by sending light waves, the corresponding electromagnetic energy value can be obtained according to the change value of the optical fiber code detected by the demodulator, the electromagnetic energy value measured based on the optical fiber coding technology is not interfered, the problem of measurement interference can be prevented by using the stability of optical fiber transmission, and the accuracy of the measurement result is improved.

Further, the magnetic field induction device comprises at least two sensing units connected through optical fibers.

Furthermore, every two connected sensing units are arranged in a U shape.

Further, the orthographic projection of the optical fiber code to the electromagnetic sensitive module falls into the electromagnetic sensitive module.

Further, the electromagnetic sensitive module is a rare earth alloy plate.

Further, the rare earth alloy plate is bonded with the optical fiber provided with the optical fiber code.

Further, the light source is a pulsed broadband light source.

Further, the fiber code comprises fiber gratings with at least two different wavelengths.

Further, the interval between every two adjacent fiber gratings is the same.

In a second aspect, an embodiment of the present invention provides a magnetic field induction measurement method, which is applied to a magnetic field induction measurement system, where the magnetic field induction measurement system includes: the circulator comprises a first end, a second end and a third end, the light source is connected with the first end of the circulator, the magnetic field sensing device is connected with the second end of the circulator, the input end of the demodulator is connected with the third end of the circulator, the magnetic field sensing device comprises at least one sensing unit, the sensing unit comprises an electromagnetic sensing module and an optical fiber which is arranged on the electromagnetic sensing module and provided with an optical fiber code, and the demodulator and the light source are respectively connected with the control module;

the magnetic field induction measuring method comprises the following steps:

the control module controls the light source to output light waves;

the control module controls the demodulator to detect reflected light of the light wave reflected by the optical fiber code in the magnetic field sensing device to obtain the current wavelength value of the optical fiber grating in the optical fiber code;

the control module obtains a wavelength change value according to the current wavelength value and the initial wavelength value;

and the control module obtains a corresponding electromagnetic energy value according to the wavelength change value.

The technical scheme of the invention at least has one of the following advantages or beneficial effects: the electromagnetic sensing module is arranged on the optical fiber provided with the optical fiber code, the electromagnetic sensing module can deform under the action of an electromagnetic field, the deformation of the electromagnetic sensing module can deform the optical fiber code in the optical fiber, so that the wavelength of the optical fiber code changes, the control module can be controlled to control the on and off of the light source, the light wave is sent to the optical fiber code in the optical fiber, the demodulator can be controlled to detect the reflected light reflected from the optical fiber code, the current wavelength value of the optical fiber grating in the optical fiber code is obtained, the wavelength change value is obtained according to the current wavelength value and the initial wavelength value, the corresponding electromagnetic energy value is obtained according to the wavelength change value, the problem of measurement interference can be prevented by utilizing the stability of optical fiber transmission, and the accuracy of the measurement result of the electromagnetic energy value is improved.

Furthermore, the magnetic field induction device comprises at least two sensing units connected through optical fibers, each two connected sensing units are arranged in a U shape, and all optical fiber codes in the at least two sensing units are arranged in a matrix;

the control module further comprises the following steps after obtaining the corresponding electromagnetic energy value according to the energy change value:

and the control module forms the electromagnetic energy value corresponding to the wavelength change value of the fiber grating in each optical fiber code into an electromagnetic energy value matrix array according to the position corresponding information of the optical fiber code on the magnetic field induction device to obtain an electromagnetic field distribution pattern and an electromagnetic energy change pattern.

In a third aspect, an embodiment of the present invention provides a measurement control apparatus, including: a memory, a control processor and a computer program stored on the memory and executable on the control processor, the control processor implementing the magnetic field induction measurement method according to the second aspect when executing the computer program.

The technical scheme of the invention at least has one of the following advantages or beneficial effects: the measurement control device can control the control module to control the on and off of the light source, the light wave is sent to the optical fiber code in the optical fiber, the control module can be controlled to control the on and off of the light source, the light wave is sent to the optical fiber code in the optical fiber, the demodulator can be controlled to detect the reflected light reflected from the optical fiber code, the current wavelength value of the optical fiber grating in the optical fiber code is obtained, the wavelength change value is obtained according to the current wavelength value and the initial wavelength value, the corresponding electromagnetic energy value is obtained according to the wavelength change value, the problem of measurement interference can be prevented by utilizing the stability of optical fiber transmission, and the accuracy of the measurement result of the electromagnetic energy value is improved.

In a fourth aspect, embodiments of the present invention provide a computer-readable storage medium storing computer-executable instructions for causing a computer to perform the magnetic field induction measurement method according to the second aspect.

Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.

Drawings

The invention is further illustrated with reference to the following figures and examples.

FIG. 1 is a schematic view of a magnetic field induction measurement system of one embodiment of the present invention;

FIG. 2 is a schematic optical fiber of a magnetic field induction measurement system according to an embodiment of the present invention;

FIG. 3 is a schematic illustration of fiber encoding of a magnetic field sensing measurement system according to an embodiment of the present invention;

FIG. 4 is a flow chart of a magnetic field induction measurement method of one embodiment of the present invention;

FIG. 5 is a flow chart of a magnetic field induction measurement method of another embodiment of the present invention;

fig. 6 is a schematic diagram of a measurement control apparatus according to an embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

It should be noted that although functional block divisions are provided in the system drawings and logical orders are shown in the flowcharts, in some cases, the steps shown and described may be performed in different orders than the block divisions in the systems or in the flowcharts. The terms first, second and the like in the description and in the claims, and the drawings described above, are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order.

The invention provides a magnetic field induction measuring system, a magnetic field induction measuring method, a magnetic field induction measuring control device and a storage medium, wherein the magnetic field induction measuring system comprises: the circulator comprises a first end, a second end and a third end, the light source is connected with the first end of the circulator, the magnetic field sensing device is connected with the second end of the circulator, the input end of the demodulator is connected with the third end of the circulator, the magnetic field sensing device comprises at least one sensing unit, the sensing unit comprises an electromagnetic sensitive module and an optical fiber arranged on the electromagnetic sensitive module and provided with an optical fiber code, and the demodulator and the light source are respectively connected with the control module. The electromagnetic sensing module is arranged on the optical fiber provided with the optical fiber code, the electromagnetic sensing module can deform under the action of an electromagnetic field, the deformation of the electromagnetic sensing module can deform the optical fiber code in the optical fiber, so that the wavelength of the optical fiber code changes, the control module can control the light source to be turned on and off, the optical fiber code in the optical fiber is identified and detected by sending light waves, the corresponding electromagnetic energy value can be obtained according to the wavelength change value of the optical fiber code detected by the demodulator, the electromagnetic energy value measured based on the optical fiber coding technology can be free from interference, the problem of measurement interference can be prevented, and the accuracy of the measurement result is improved.

Referring to fig. 1 to 3, an embodiment of the present invention provides a magnetic field induction measurement system, including: the circulator 130 comprises a first end, a second end and a third end, the light source 120 is connected with the first end of the circulator 130, the magnetic field sensing device 140 is connected with the second end of the circulator 130, the input end of the demodulator 150 is connected with the third end of the circulator 130, the magnetic field sensing device 140 comprises at least one sensing unit 310, the sensing unit 310 comprises an electromagnetic sensitive module 141 and an optical fiber 142 which is arranged on the electromagnetic sensitive module 141 and provided with an optical fiber code 210, and the demodulator 150 and the light source 120 are respectively connected with the control module 110.

The electromagnetic sensing module 141 is arranged on the optical fiber 142 provided with the optical fiber code 210, the electromagnetic sensing module 141 is deformed under the action of an electromagnetic field, the deformation of the electromagnetic sensing module 141 can deform the optical fiber code 210 in the optical fiber, so that the wavelength of the optical fiber code 210 is changed, the control module 110 can control the light source 120 to be turned on and off, the light wave is sent to detect the reflected wave reflected by the optical fiber code 210 in the optical fiber, the current wavelength value of the optical fiber code 210 is obtained, the wavelength change value can be obtained according to the current wavelength value and the initial wavelength value, the corresponding electromagnetic energy value can be obtained according to the wavelength change value of the optical fiber code 210 detected by the demodulator 150, the electromagnetic energy value measured based on the optical fiber coding technology can be free from interference, the problem of measurement interference can be prevented, and the accuracy of the measurement result is improved.

The light source 120 is a pulsed broadband light source 120. The pulsed broadband light source 120 can provide a stable light wave output for a magnetic field sensing measurement system, and the wavelength band of the light wave can be determined according to the number of the required optical fiber codes 210. In the existing fiber grating processing technology, the fiber grating has a wavelength error, and then the calculation formula of the wavelength band of the light wave can be as follows:

wherein F_nWavelength band of light wave, F_rIs the wavelength error, F, of the fiber grating_l3dB bandwidth, n is the number of fiber codes 210. The light source 120 may also be other lasers, and the present implementation is not limited solely.

It should be noted that, in the present embodiment, the first end, the second end and the third end of the circulator 130 are arranged in sequence and the unidirectional passing directions of the three ports are consistent, and since the whole structure involves a plurality of optical components, the loss in the optical fiber should be minimized to ensure the accuracy of the measurement.

The optical fiber code 210 is an optical fiber reflection code, and the light wave output by the light source 120 can be reflected to the demodulator 150 through the optical fiber code 210 for detection.

Referring to fig. 3, the magnetic field sensing apparatus 140 includes at least two sensing units 310 connected by an optical fiber, and each two connected sensing units 310 are disposed in a U-shape. The magnetic field sensing device 140 may include a plurality of sensing units 310, each sensing unit 310 is connected by an optical fiber, the shape of the magnetic field sensing device 140 formed by connecting the plurality of sensing units 310 may be S-shaped, the optical fiber 142 provided with the optical fiber code 210 in each sensing unit 310 is adhered to the electromagnetic sensing module 141, each two connected sensing units 310 are arranged in a U shape, the plurality of sensing units 310 can arrange the optical fiber codes 210 to form a multi-element matrix, for example, a 10 × 10 optical fiber code 210 matrix, when the electromagnetic sensing module 141 is subjected to the action of electromagnetic waves, the strain can affect the optical fiber, the wavelength of the optical fiber code 210 is affected by the strain, the control module 110 can analyze the data detected by the demodulator 150 to obtain the wavelength combination of each optical fiber code 210, so as to identify the point position of each optical fiber code 210 in the magnetic field sensing device 140, the electromagnetic energy value corresponding to the wavelength change of the fiber code 210 can be calculated according to the wavelength change value of each fiber grating in the fiber code 210, and then the fiber code 210 corresponds to the matrix position on the device, so that an electromagnetic energy matrix array of each point on the matrix can be formed, and the electromagnetic field distribution pattern and the energy intensity can be completed. In combination with the transmitter, the distance between the object generating the electromagnetic field and the magnetic field sensing device 140 can be calculated, thereby preventing the problem of measurement interference and improving the accuracy of the measurement result.

In an embodiment, the electromagnetic sensitive module 141 may be made of rare earth, the rare earth may be made into a rare earth alloy plate, the rare earth alloy plate is bonded to the optical fiber 142 provided with the optical fiber code 210, when the rare earth alloy plate is subjected to a strain caused by an electromagnetic wave, the deformation of the optical fiber is affected, and thus the wavelength change of the optical fiber code 210 in the optical fiber is affected, the control module 110 may analyze data detected by the demodulator 150 to obtain a wavelength combination of each optical fiber code 210, identify a point position of each optical fiber code 210 in the magnetic field sensing device 140, calculate an electromagnetic energy value corresponding to the wavelength change of the optical fiber code 210 according to each fiber grating wavelength change value in the optical fiber code 210, correspond the optical fiber code 210 to a matrix position on the device, and form an electromagnetic energy matrix array of each point on the matrix, so as to complete the electromagnetic field distribution pattern and the energy intensity, the problem of measurement interference can be prevented, and the accuracy of the measurement result is improved. It should be noted that the material of the electromagnetic sensitive module 141 may also be other materials, and this embodiment is not limited to the only one.

In an embodiment, the fiber code 210 includes at least two fiber gratings with different wavelengths, and the interval between each two adjacent fiber gratings is the same, so the generated fiber code 210 may be a different-wavelength fiber reflection code group, but the present embodiment does not limit the structure of the fiber grating of the fiber code 210 uniquely. For example: the pitches of the fiber gratings in the fiber code 210 may not be equal.

Referring to fig. 4, the magnetic field induction measuring method based on the magnetic field induction measuring system in the above embodiment includes the following steps:

s410, controlling a light source to output light waves;

s420, controlling the demodulator to detect reflected light of the optical wave reflected by the optical fiber code in the magnetic field sensing device to obtain the current wavelength value of the optical fiber grating in the optical fiber code;

s430, obtaining a wavelength change value according to the current wavelength value and the initial wavelength value;

and S440, obtaining a corresponding electromagnetic energy value according to the wavelength change value.

The electromagnetic sensing module is arranged on the optical fiber provided with the optical fiber code, the electromagnetic sensing module can deform under the action of an electromagnetic field, the deformation of the electromagnetic sensing module can deform the optical fiber code in the optical fiber, so that the wavelength of the optical fiber code changes, the control module can be controlled to control the on and off of the light source, the light wave is sent to the optical fiber code in the optical fiber, the demodulator can be controlled to detect the reflected light reflected from the optical fiber code, the current wavelength value of the optical fiber code is obtained, the wavelength change value is obtained according to the current wavelength value and the initial wavelength value, the corresponding electromagnetic energy value is obtained according to the wavelength change value, the problem of measuring interference can be prevented by utilizing the stability of optical fiber transmission, and the accuracy of the measuring result of the electromagnetic energy value is improved.

Referring to fig. 5, after the steps in the embodiment of the magnetic field induction measuring method described above obtain the corresponding electromagnetic energy value according to the energy variation value, the method further includes the following steps:

s510, the control module forms an electromagnetic energy value matrix array with the electromagnetic energy value corresponding to the wavelength change value of the fiber bragg grating in each fiber code according to the position corresponding information of the fiber codes on the magnetic field induction device to obtain an electromagnetic field distribution graph and an electromagnetic energy change graph.

The electromagnetic energy values corresponding to the wavelength change values of the optical fiber codes are arranged in a matrix mode, so that an electromagnetic field distribution graph and an electromagnetic energy change graph can be obtained, the distance between an object generating an electromagnetic field and a magnetic field induction device can be calculated by combining a transmitter, the problem of measurement interference can be prevented through the electromagnetic energy values measured based on the optical fiber coding technology, and the accuracy of a measurement result is improved.

Referring to fig. 6, fig. 6 is a schematic diagram of a measurement control apparatus 600 according to an embodiment of the present invention. The measurement control apparatus 600 according to the embodiment of the present invention is built in the magnetic field induction measurement system, and includes one or more control processors 610 and a memory 620, and fig. 6 illustrates one control processor 610 and one memory 620 as an example.

The control processor 610 and the memory 620 may be connected by a bus or other means, such as by a bus in fig. 6.

The memory 620, as a non-transitory computer readable storage medium, may be used to store non-transitory software programs as well as non-transitory computer executable programs. Further, the memory 620 may include high speed random access memory, and may also include non-transitory memory, such as at least one magnetic disk storage device, flash memory device, or other non-transitory solid state storage device. In some embodiments, the memory 620 optionally includes memory 620 located remotely from the control processor 610, and these remote memories 620 may be connected to the measurement control device 600 via a network. Examples of such networks include, but are not limited to, the internet, intranets, local area networks, mobile communication networks, and combinations thereof.

Those skilled in the art will appreciate that the configuration of the apparatus shown in FIG. 6 does not constitute a limitation of the measurement control apparatus 600, and may include more or fewer components than those shown, or some components in combination, or a different arrangement of components.

The non-transitory software programs and instructions required to implement the magnetic field induction measurement method applied to the measurement control apparatus 600 in the above-described embodiment are stored in the memory 620, and when executed by the control processor 610, perform the magnetic field induction measurement method applied to the measurement control apparatus 600 in the above-described embodiment, for example, perform the method steps S410 to S440 in fig. 4 and the method step S510 in fig. 5 described above.

The above-described embodiments of the apparatus are merely illustrative, wherein the units illustrated as separate components may or may not be physically separate, i.e. may be located in one place, or may also be distributed over a plurality of network elements. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of the present embodiment.

Furthermore, an embodiment of the present invention also provides a computer-readable storage medium, which stores computer-executable instructions, which are executed by one or more control processors, for example, by one of the control processors 610 in fig. 6, and can cause the one or more control processors 610 to execute the magnetic field induction measurement method in the above-described method embodiment, for example, execute the above-described method steps S410 to S440 in fig. 4, and the method step S510 in fig. 5.

One of ordinary skill in the art will appreciate that all or some of the steps, systems, and methods disclosed above may be implemented as software, firmware, hardware, and suitable combinations thereof. Some or all of the physical components may be implemented as software executed by a processor, such as a central processing unit, digital signal processor, or microprocessor, or as hardware, or as an integrated circuit, such as an application specific integrated circuit. Such software may be distributed on computer readable media, which may include computer storage media (or non-transitory media) and communication media (or transitory media). The term computer storage media includes volatile and nonvolatile, removable and non-removable media implemented in any method or technology for storage of information such as computer readable instructions, data structures, program modules or other data, as is well known to those of ordinary skill in the art. Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, Digital Versatile Disks (DVD) or other optical disk storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to store the desired information and which can accessed by a computer. In addition, communication media typically embodies computer readable instructions, data structures, program modules or other data in a modulated data signal such as a carrier wave or other transport mechanism and includes any information delivery media as known to those skilled in the art.

The above is only a preferred embodiment of the present invention, and the present invention is not limited to the above embodiments, and the present invention shall fall within the protection scope of the present invention as long as the technical effects of the present invention are achieved by the same means.