Distance measurement device and operation method

Abstract

To suppress a propagation loss of detection wave in an oversized waveguide connecting transmission / reception means and a second antenna in a distance measurement device, and to provide an operation method for supplying an object to a container of a facility on the basis of a measurement result by using such a distance measurement device.SOLUTION: A distance measurement device includes transmission / reception means 20 for transmitting and receiving detection wave M, a first antenna 24 connected to the transmission / reception means 20 by a first waveguide 23, a second oversized waveguide 25 connected to an antenna surface 24a of the first antenna 24 and having an inside diameter equal to an aperture of the antenna surface 24a or larger than the aperture of the antenna surface 24a, and a second antenna 26 connected to the second oversized waveguide 25 and having an aperture of the antenna surface 24a larger than the aperture of the antenna surface 26a of the first antenna 24. The detection wave M from the transmission / reception means 20 is sent to the second antenna 26, and the detection wave M is transmitted and received via the second antenna 26.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a distance measurement device that detects the distance to various objects such as solids and liquids, and an operating method for supplying objects to a container of equipment based on the measurement results obtained by the distance measurement device. [Background technology]

[0002] Distance measuring devices are known that transmit detection waves toward objects that have been placed and accumulated in containers of various facilities, such as powdered coal in coke ovens, molten steel in converters and ladle furnaces, coal in hoppers, garbage in incinerators, grains in storage facilities such as silos, and various liquids, and receive the reflected waves to measure the distance to the objects and determine the amount of objects accumulated in the containers.

[0003] For example, a coke oven has multiple coal loading ports on the top, and coal is loaded sequentially through the loading ports as coal loading cars are moved. At this time, it is necessary to measure the loading level of the coal loaded into the coke oven and load as much coal as possible to increase productivity.

[0004] As a method for measuring the coal level, the applicant has proposed a measuring device using microwaves or millimeter waves as detection waves, as described in Patent Document 1. As shown in FIG. 7, the measuring device is installed inside a typical coal loading car 1. The coal loading car 1 includes a coal receiving hopper 10 that stores coal C supplied from an external source, and a coal feeder 12 that sends the coal C from the coal receiving hopper 10 to a coal charging chute 11. The lower end of the coal charging chute 11 is fitted with a sleeve 13 that narrows inward and matches the diameter of the coal loading port 102 of the coke oven 100. The coal loading car 1 then moves along a rail 101 fixed to the top surface of the coke oven 100, for example, in the front-to-back direction of the drawing.

[0005] An opening 11b is formed in the center of the ceiling surface 11a of the coal charging chute 11, and one end of a guide pipe 40 is attached to the opening 11b. An antenna 22 of the microwave or millimeter wave transmitting / receiving means 20 is attached to the other end of the guide pipe 40. Furthermore, a gas supply port 35 is provided in the side wall of the guide pipe 40 near the antenna 22, and a purge gas is supplied through the gas supply port 35.

[0006] In the coal loading level device configured as described above, when measuring the coal loading level, as indicated by the symbol M and the arrow in the figure, microwaves and millimeter waves from the transmitting / receiving means 20 are transmitted from the antenna 22, propagated through the guide pipe 40, and proceed to the coal charging chute 11 and sleeve 13, then through the coal loading port 102 and into the inside of the coke oven 100. The microwaves and millimeter waves are then reflected by the surface of the coal C' piled up inside the oven and received by the transmitting / receiving means 20 via the reverse path. The pile level of the coal C' is then calculated based on the time difference between the transmission and reception of the microwaves and millimeter waves.

[0007] 7, the guide pipe 40 is a straight pipe, and the transmitting / receiving means 20 located directly above the guide pipe 40 is susceptible to thermal load due to the high heat from the coke oven 100. Therefore, Patent Document 1 proposes an L-shaped guide pipe 40 with a reflector plate installed at the bent portion, as shown in Fig. 8. Note that reference numeral 30 in the figure denotes a filter 30 made of a material that prevents dust from entering from the coke oven 100 and transmits microwaves and millimeter waves.

[0008] As shown in the figure, this guide pipe 40 has a first reflector 41 at a 90° bend, has the transmitting / receiving means 20 at one end, and a second reflector 42 at the other end. The first reflector 41 and the second reflector 42 are both 45° reflectors, with the reflecting surface of the first reflector 41 inclined upward by 45° so as to face the transmitting / receiving means 20 and the reflecting surfaces of the second reflector 42, and the second reflector 42 inclined downward by 45° so as to face the reflecting surface of the first reflector 41 and the coal injection chute 11.

[0009] Additionally, the straight pipe section 40a of the guide pipe 40 that connects the transmitting / receiving means 20 and the first reflecting plate 41 houses an antenna 22 that is connected to the transmitting / receiving means 20. Furthermore, the first reflecting plate 41 and the second reflecting plate 42 are connected by the horizontal pipe section 40b of the guide pipe 40, and the hanging section 40c of the guide pipe 40 that faces the coal charging chute 11 is attached to the second reflecting plate 42.

[0010] In this way, the guide pipe 40 allows the transmitting / receiving means 20 (and the controller) to be separated from the high-temperature coke oven 100. The guide pipes 40 (40a, 40b, 40c) are large-diameter metal pipes, for example, with an inner diameter of 150 mm. The reason for making the guide pipes 40 (40a, 40b, 40c) large is that in order to increase the gain of the antenna 22, the antenna diameter needs to be large and it is necessary to directly connect the antenna to the transmitting / receiving means 20 via a 2.8 mm waveguide 21. [Prior art documents] [Patent documents]

[0011] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-172184 Summary of the Invention [Problem to be solved by the invention]

[0012] In a distance measurement device that measures the distance to an object using a detection wave, a transmitter / receiver for the detection wave and an antenna for transmitting the detection wave to the object and receiving the reflected wave are connected by a waveguide. In the measurement device of Patent Document 1, the transmitter / receiver 20 and the antenna 22 are also connected by a waveguide 21. In recent years, millimeter waves have become common because of their excellent directivity, but in the case of 79 GHz millimeter waves, a narrow waveguide 21 with an inner diameter of φ2.8 mm is used in consideration of propagation in the fundamental millimeter wave mode.

[0013] However, in such a small-diameter waveguide 21, the longer the distance between the transmitting / receiving means 20 and the antenna 22, the greater the propagation loss within the pipe, and even in a straight pipe, propagation is no longer possible once the pipe is approximately 600 mm or longer. As shown in Figure 8, if the waveguide 21 is bent to reduce the thermal load on the transmitting / receiving means 20, the propagation loss becomes even greater, and furthermore, forming the bent portion is difficult. Furthermore, there is a risk that dust may enter the guide pipe 40 through the opening 11b in Figure 7, causing measurement errors.

[0014] As described above, since there is a restriction on the length of the waveguide, the distance between the transmitting / receiving means and the antenna cannot be increased, and the installation positions of the transmitting / receiving means and the antenna in the detection device are restricted.

[0015] Furthermore, as shown in FIG. 8, when a bent guide pipe 40 is used, it is necessary to use reflectors (first reflector 41 and second reflector 42) at the bent portion, which makes the guide pipe 40 heavier and larger overall.

[0016] In place of the waveguide 21, a coaxial cable may be used to connect the transmitting / receiving means 20 and the antenna 22, but the same problem occurs when a coaxial cable is used, and the cable length is generally limited to 300 mm.

[0017] The present invention has been made in view of the above circumstances, and aims to suppress propagation loss of a detection wave in an oversized waveguide that connects a transmitting / receiving means and a second antenna in a distance measurement device. Another aim of the present invention is to provide an operating method that uses such a distance measurement device and supplies an object to a container of equipment based on measurement results. [Means for solving the problem]

[0018] In order to solve the above problems, the present invention provides the following distance measuring device (1).

[0019] (1) A distance measuring device that transmits a detection wave toward various objects, receives the detection wave reflected by the objects, and measures the distance to the objects, a transmitting / receiving means for transmitting and receiving the detection wave; a first antenna connected to the transmitting / receiving means by a first waveguide; a second oversized waveguide connected to an antenna surface of the first antenna and having an inner diameter equal to or larger than the diameter of the antenna surface; a second antenna connected to the second oversized waveguide and having an antenna face diameter larger than an antenna face diameter of the first antenna; A distance measuring device, characterized in that the detection wave from the transmitting / receiving means is sent to the second antenna, and the detection wave is transmitted and received via the second antenna.

[0020] Furthermore, preferred embodiments of the present invention relating to the distance measuring device relate to the following (2) to (12).

[0021] (2) The distance measuring device for a charge described in (1), characterized in that the detection wave is transmitted and received as a circularly polarized wave. (3) The distance measuring device according to (1) or (2), wherein the second oversized waveguide has a bent or curved portion. (4) The distance measuring device according to (1) or (2), characterized in that it has a measurement mode in which the surface of the object is measured multiple times and the average value is calculated. (5) A distance measuring device according to (1) or (2), which is provided with a measurement mode that measures the surface of the object multiple times and averages either or both of the received beat waveform and the distance spectrum waveform obtained by FFT processing of the received beat waveform. (6) The distance measuring device according to (3), characterized in that it has a measurement mode in which the surface of the object is measured multiple times and the average value is calculated. (7) A distance measuring device according to (3), which is provided with a measurement mode that measures the surface of the object multiple times and averages either or both of the obtained received beat waveform and the distance spectrum waveform obtained by FFT processing of the received beat waveform. (8) The distance measuring device according to (1) or (2), wherein the detection wave is a millimeter wave. (9) The distance measuring device according to (3), wherein the detection wave is a millimeter wave. (10) The distance measuring device according to (4), wherein the detection wave is a millimeter wave. (11) The distance measuring device according to any one of (5) to (7), wherein the detection wave is a millimeter wave. (12) A distance measuring device as described in (1) or (2), which is installed in a container of various equipment, measures the distance to the object supplied to the container, and determines the amount of accumulation of the object in the container.

[0022] In order to solve the above problems, the present invention provides the following operating method (13).

[0023] (13) An operating method characterized by supplying the object to the container of the various facilities based on the measurement results by the distance measuring device described in (12). [Effects of the Invention]

[0024] According to the distance measuring device of the present invention, the first antenna is connected to the transmitting / receiving means by a first waveguide with an inner diameter corresponding to the detection wave (for example, a thin tube with an inner diameter of 2.8 mm for 79 GHz millimeter waves), so the detection wave is transmitted and received via the first antenna with almost no attenuation. Furthermore, the detection wave from the first antenna propagates through a second oversized waveguide with an inner diameter equal to or larger than the aperture diameter of the antenna face of the first antenna, so that the detection wave is sent to the second antenna with extremely low propagation loss even in the second oversized waveguide. Because the second antenna has an aperture with a larger diameter than the aperture of the first antenna, the gain of transmission and reception by the second antenna is increased.

[0025] As described above, according to the distance measuring device of the present invention, the detection wave from the transmitting / receiving means is transmitted and received with extremely low loss, and furthermore, the gain is increased, improving the signal-to-noise ratio. Furthermore, the second oversized waveguide can be lengthened or bent, which reduces the thermal load on the transmitting / receiving means and eliminates restrictions on the installation position of the transmitting / receiving means in the distance measuring device. Furthermore, because the lower end (i.e., opening 11b) is not open like the guide pipe 40 in Figure 7, measures against dust are not required.

[0026] In addition, the distance measuring device of the present invention can be installed in containers of various facilities, and can more accurately detect the distance to objects in the container.Based on the measurement results, objects can be supplied accurately in various facilities, enabling smooth operation. [Brief explanation of the drawings]

[0027] [Figure 1] FIG. 1 is a cross-sectional view that schematically shows the configuration of a transmitting / receiving means, a first waveguide, a first antenna, a second oversized waveguide, and a second antenna in a distance measuring device of the present invention. [Figure 2] FIG. 2 is an enlarged cross-sectional view showing the connection portion between the first waveguide, the first antenna, and the second oversized waveguide. [Figure 3A]FIG. 3A is a schematic diagram showing the antenna configuration used in the "Propagation Loss Verification Experiment," where (A) shows the case where a second antenna 26A is directly connected to the transmitting / receiving means 20 and the antenna diameter is the same as that of the second antenna 26, and (B) shows the case where a first antenna 24 is connected to the transmitting / receiving means 20 via a first waveguide 23, and further, a second antenna 26 is connected to the first antenna 24 via a second oversized waveguide 25. [Figure 3B] FIG. 3B is an enlarged cross-sectional view of the second antenna 26A shown in FIG. 3A(A). [Figure 3C] FIG. 3C is an enlarged cross-sectional view of the second antenna 26 shown in FIG. 3A(B). [Figure 4] FIG. 4 is a diagram showing the results of the "Propagation Loss Verification Experiment" (distance vs. received signal level (spectrum level)). [Figure 5] FIG. 5 is a diagram illustrating transmission and reception when the detection wave is circularly polarized. [Figure 6] FIG. 6 is a cross-sectional view showing the dustproof structure of the second antenna. [Figure 7] FIG. 7 is a cross-sectional view that schematically shows an example of the measuring device described in Patent Document 1. [Figure 8] FIG. 8 is a cross-sectional view schematically showing another example of the measuring device described in Patent Document 1. DETAILED DESCRIPTION OF THE INVENTION

[0028] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to the embodiments described below, and can be implemented with any modifications within the scope of the gist of the present invention.

[0029] [Distance measuring device] (Basic configuration) The distance measurement device of this embodiment is a device that transmits detection waves toward objects such as powdered coal in a coke oven, molten steel in a converter or ladle, coal in a hopper, garbage in an incinerator, grains in a storage facility such as a silo, and various liquids, and receives reflected waves from the objects to measure the distance to the objects. For example, it may be installed in a container of various facilities to measure the distance to objects accumulated in the container and determine the amount of accumulated objects. The distance measurement device of this embodiment is characterized by the configuration of the means for transmitting and receiving detection waves and the antenna. Note that the description will be given using a case where a 79 GHz millimeter wave is used as the detection wave.

[0030] As shown in Fig. 1, a first antenna 24 is connected to the transmitting / receiving means 20 via a first waveguide 23. The first waveguide 23 is a thin straight pipe with an inner diameter of φ2.8 mm so as to support propagation of only the fundamental TE11 mode of 79 GHz millimeter waves. Therefore, the millimeter waves from the transmitting / receiving means 20 propagate well through the first waveguide 23 in the TE11 mode.

[0031] A second oversized waveguide 25 having an inner diameter equal to or larger than the diameter of the opening of the antenna surface 24a is connected to the first antenna 24. Fig. 2 is an enlarged cross-sectional view showing the connection portion between the first waveguide 23, the first antenna 24, and the second oversized waveguide 25. Note that the second oversized waveguide 25 shown in Fig. 2 has an inner diameter larger than the diameter of the antenna surface 24a of the first antenna 24, but it may have an inner diameter equal to the diameter of the antenna surface 24a of the first antenna 24.

[0032] Alternatively, both the first waveguide 23 and the first antenna 24 may be formed as cavities in a common cylinder 27. That is, the first antenna 24 is formed continuous with a cylindrical cavity 23A of φ2.8 mm corresponding to the first waveguide 23, and a tapered cavity 24A whose diameter gradually increases toward the second oversized waveguide 25 is formed inside the cylinder 27. The inner peripheral surface of the second oversized waveguide 25 is fitted onto the outer peripheral surface of the cylinder 27 near the end face in which the cavities 23A and 24A are formed, thereby connecting the cylinder 27 and the second oversized waveguide 25.

[0033] The inner diameter of second oversized waveguide 25 is larger than the inner diameter of first waveguide 23 and is the same as the inner diameter of the opening of antenna surface 24a of first antenna 24 or larger than the diameter of antenna surface 24a. However, the inner diameter of second oversized waveguide 25 can be set taking into consideration the propagation loss of millimeter waves from first antenna 24 and the overall size of the distance measurement device that receives the reflected waves to measure the distance to an object and determine the amount of object deposition in the container, and the inner diameter can be set to, for example, φ15 mm.

[0034] A second antenna 26 is connected to the second oversized waveguide 25. There are no particular restrictions on the type of second antenna 26, but it may be one to which a dielectric lens 29 is attached, as shown in the figure, for example. The dielectric lens 29 prevents dust from entering the second antenna 26 and the second oversized waveguide 25. Furthermore, if a dielectric lens 29 with a short focal length is used, the height of the antenna can be reduced.

[0035] Therefore, the millimeter waves from the transmitting / receiving means 20 propagate through the first waveguide 23 in TE11 mode with low loss, then propagate through the second oversized waveguide 25 while maintaining almost the TE11 mode with minimal propagation loss, and are transmitted and received via the second antenna 26.

[0036] The second antenna 26 is a large antenna with an opening on the antenna surface 26a that is larger in diameter than the antenna surface 24a of the first antenna 24, which can increase the gain during transmission and reception and improve the signal-to-noise ratio. Therefore, as shown in Fig. 2, the length L of the cavity 23A of the first waveguide 23 can be shortened, specifically, to 100 mm or less when using a 79 GHz millimeter wave, thereby reducing the size and weight of the entire device.

[0037] In the distance measuring device configured as described above, as indicated by the symbol M in the figure, a millimeter wave (detection wave M) from the transmitting / receiving means 20 passes through the first waveguide 23, the first antenna 24, and the second oversized waveguide 25, and is transmitted from the second antenna 26 to the load material 210 through the opening 201 of the container 200. The millimeter wave (reflected wave) reflected by the surface of the load material 210 is then received by the second antenna 26. The reflected wave is then received by the second antenna 26 and sent to the second oversized waveguide 25, the first antenna, and the first waveguide 23, and is received by the transmitting / receiving means 20. At this time, the propagation loss of the millimeter wave in the first waveguide 23 and the second oversized waveguide 25 is extremely low, and the wave propagates while maintaining substantially the TE11 mode, thereby achieving good transmission and reception.

[0038] The second oversized waveguide 25 may be a straight pipe, or may have bent (curved) sections 25A formed at appropriate locations (two locations in FIG. 1 ) as shown. The first waveguide 23 is generally a straight pipe to prevent propagation loss. Therefore, if the second oversized waveguide 25 is a straight pipe, the transmitting / receiving means 20 will be located directly above the opening 201 of the container 200. Therefore, if the inside of the container 200 is hot, such as in a blast furnace, coke oven, or incinerator, the transmitting / receiving means 20 will be subjected to thermal load through the opening 201. The second oversized waveguide 25 can be bent or curved freely without increasing the propagation loss of millimeter waves. When bending or curving, a straight pipe and a curved pipe may be appropriately combined and connected with a union 28.

[0039] The angle of the bend in the second oversized waveguide 25 is not limited to 90° and can be any angle, which increases the degree of freedom in design.

[0040] (Propagation loss verification experiment) Next, the following verification experiment was carried out to verify the propagation loss in the distance measuring device of this embodiment.

[0041] Fig. 3A is a schematic diagram showing the antenna configuration used in the verification experiment. Here, as shown in Fig. 3A(A), a second antenna 26A is directly connected to the transmitting / receiving means 20, and the antenna diameter is the same as that of the second antenna 26 shown in Fig. 3A(B). As shown in Fig. 3A(B), a first antenna 24 is connected to the transmitting / receiving means 20 via a first waveguide 23, and further, a second antenna 26 is connected to the first antenna 24 via a second oversized waveguide 25. Tests were conducted to transmit and receive signals to and from a detected object 50.

[0042] The second oversized waveguide 25 has an inner diameter of 15 mm and a length of 5 m. In (A) of Fig. 3A, the distance from the tip of the second antenna 26A to the detected object 50 is 9 m, and in (B) of Fig. 3A, the distance from the tip of the second antenna 26A to the detected object 50 is 4 m. The second antenna 26A shown in FIG. 3A(A) has the same antenna diameter as the second antenna 26 shown in FIG. 3A(B), and is therefore referred to as the second antenna for convenience. FIG. 3B is an enlarged cross-sectional view of the second antenna 26A shown in FIG. 3A(A), and FIG. 3C is an enlarged cross-sectional view of the second antenna 26 shown in FIG. 3A(B).

[0043] The results are shown in Figure 4, where Figure 4(A) is a diagram showing the "distance vs. received signal level (spectrum level)" for (A) in Figure 3A, i.e., when the distance from second antenna 26A to detected object 50 is 9 m, and Figure 4(B) is a diagram showing the "distance vs. received signal level (spectrum level)" for (B) in Figure 3A, i.e., when the distance from second antenna 26 connected to second oversized waveguide 25 to detected object 50 is 4 m.

[0044] Comparing Figures 4(A) and 4(B), the change in received signal level with distance is nearly identical, with the received signal level (spectrum level) at a distance of 9 m being 122 dB in both cases. Generally, the power sensitivity of a radio wave beam emitted from an antenna decreases as the distance to the target increases, resulting in a smaller reflected signal returning to the antenna. However, as shown in the figure, the fact that the received signal level is nearly identical in both cases indicates that the decrease in received signal level due to the decrease in power sensitivity caused by the additional 5 m of spatial propagation is nearly equal to the decrease in received signal level due to propagation loss in the 5-m-long second oversized waveguide 25. This shows that even when the target location must be measured via a complex path, by installing an antenna at a suitable location within the range of measurement and using a second oversized waveguide 25 formed by appropriately combining bends and curves, it is possible to measure with sensitivity comparable to that of a spatial propagation system that does not use an oversized waveguide.

[0045] Circularly polarized millimeter waves can also be used as the detection wave M. As shown in FIG. 5, the transmitting / receiving means 20 includes a transmitting circuit 31, a receiving circuit 32, and a circular polarizer 33. On the right side of FIG. 5, the arrows indicate the electric field directions of the millimeter waves at each component. The receiving circuit 32 receives linearly polarized waves whose electric field direction is different from that of the linearly polarized waves transmitted from the transmitting circuit 31. The transmitting circuit 31 and the receiving circuit 32 are separated, and a circular polarizer 33 is interposed between them and the first waveguide 23. Here, the "inner diameter" shown in FIG. 5 schematically indicates the inner diameter of the first waveguide 23, the second oversized waveguide 25, and the second antenna 26, from top to bottom.

[0046] Then, the millimeter wave Mo', whose electric field direction is rotated in one direction (right-handed in the figure; hereinafter referred to as "right-handed circular polarization") by the circular polarization generator 33, is sent from the transmitting circuit 31 to the first antenna 24 through the first waveguide 23, and propagates through the second oversized waveguide 25 while maintaining the right-handed electric field, and is transmitted from the second antenna 26 toward the load 210.

[0047] When the transmitted right-handed circularly polarized wave Mo' is reflected by the load 210, the direction of rotation of the electric field is reversed, and it becomes a millimeter wave (hereinafter referred to as a "left-handed circularly polarized wave") Mr', which has a left-handed electric field. Then, while still maintaining the left-handed electric field, it is received by the second antenna 26 and sent to the circular polarized wave generator 33 via the second oversized waveguide 25, the first antenna 24, and the first waveguide 23. Then, as it passes through the circular polarized wave generator 33, the left-handed circularly polarized wave Mr' is converted into a linearly polarized wave with an electric field direction different from that of the linearly polarized wave from the transmitting circuit 31, and sent to the receiving circuit 32.

[0048] In this way, by using circularly polarized millimeter waves, the receiving circuit 32 receives only millimeter waves Mr', which have an electric field different from that of the millimeter waves Mo' from the transmitting circuit 31, and therefore the transmitted waves and received waves can be almost completely separated, thereby significantly improving detection accuracy.

[0049] Furthermore, in order to reduce the noise level and increase the SNR, measurements are repeated multiple times (N times) and the average value is calculated, thereby reducing the floor noise power by 1 / N.

[0050] Alternatively, the floor noise power can be reduced by 1 / N by performing multiple measurements and averaging either the waveform of the received beat obtained or the distance spectrum waveform obtained by FFT processing of the received beat waveform. The received beat waveform is the waveform obtained by mixing the transmitted and received waves in an FMCW rangefinder. The beat waveform is then processed using FFT to create a distance spectrum level waveform.

[0051] Since the second antenna 26 is located close to the opening 201 of the container 200, dust floating inside the container 200 can easily adhere to the second antenna 26 through the opening 201. Therefore, as shown in FIG. 6, the second antenna 26 can be enclosed in a cylindrical body 60 and the antenna surface 26a can be closed with a ceramic board 65. The ceramic board 65 has a handle 66 that is used for insertion and removal. Since dust adheres to the ceramic board 65, the second antenna 26, as well as the second oversized waveguide 25, first antenna 24, and first waveguide 23, can be kept clean. Furthermore, as shown in the figure, the ceramic board 65 is inclined with respect to the antenna surface 26a of the second antenna 26 to suppress reflection of millimeter waves by itself.

[0052] In the measuring device of Patent Document 1 shown in Fig. 7, the detection wave from the antenna 22 propagates through the guide pipe 40 and is transmitted from the end of the guide pipe 40 to the coal charging chute 11. Although a purge gas is supplied to the guide pipe 40, adhesion of coal C fragments and the like to the inner wall of the guide pipe 40 is unavoidable, making periodic cleaning essential. In order to further reduce the thermal load on the transmitting / receiving means 20 and for space reasons, the length of the guide pipe 40 needs to be increased, and the longer the pipe length, the more difficult cleaning becomes.

[0053] In contrast, the dustproof structure shown in Figure 6 requires only the insertion and removal of the ceramic board 65 for cleaning, which significantly reduces the amount of cleaning work and also prevents dust from adhering to the dielectric lens 29.

[0054] [Operation method] The present embodiment also relates to an operation method for supplying objects to, for example, a container of equipment based on the measurement results of the distance measurement device. According to this operation method, the distance to the object that has been supplied to and accumulated in the container of various equipment is measured using the distance measurement device, and the object is supplied appropriately based on the measurement results, thereby enabling stable operation. [Explanation of symbols]

[0055] 23 First Waveguide 23A (first waveguide) cavity 24 First Antenna 24A (first antenna) cavity 24a (first antenna) antenna surface 25 Second Oversized Waveguide 25A Bending section (curved section) 26,26A Second antenna 26a (second antenna) antenna surface 27 Cylinder 28 Union 29 Dielectric Lens 31 Transmitting circuit 32 Receiving circuit 33 Circularly Polarized Wave Generator 50 Detected Objects 60 cylinder 65 Ceramic Board 66 Handle 200 containers 201 Aperture 210 Charge L length of cavity 23A

Claims

1. A distance measuring device that transmits a detection wave toward various objects, receives the detection wave reflected by the objects, and measures the distance to the objects, a transmitting / receiving means for transmitting and receiving the detection wave; a first antenna connected to the transmitting / receiving means by a first waveguide; a second oversized waveguide connected to an antenna surface of the first antenna and having an inner diameter equal to or larger than the diameter of the antenna surface; a second antenna connected to the second oversized waveguide and having an antenna face diameter larger than an antenna face diameter of the first antenna; A distance measuring device, characterized in that the detection wave from the transmitting / receiving means is sent to the second antenna, and the detection wave is transmitted and received via the second antenna.

2. 2. The distance measuring device according to claim 1, wherein the detection wave is transmitted and received as a circularly polarized wave.

3. 3. A distance measuring device according to claim 1, wherein the second oversized waveguide has a bent or curved portion.

4. 3. The distance measuring device according to claim 1, further comprising a measurement mode for measuring the surface of the object a plurality of times and calculating an average value of the measurements.

5. 3. The distance measuring device according to claim 1, further comprising a measurement mode that measures the surface of the object multiple times and averages either or both of the obtained received beat waveform and a distance spectrum waveform obtained by FFT processing of the received beat waveform.

6. 4. The distance measuring device according to claim 3, further comprising a measurement mode for measuring the surface of the object a plurality of times and calculating the average value of the measurements.

7. 4. The distance measuring device according to claim 3, further comprising a measurement mode that measures the surface of the object multiple times and averages either or both of the obtained received beat waveform and a distance spectrum waveform obtained by FFT processing of the received beat waveform.

8. 3. The distance measuring device according to claim 1, wherein the detection wave is a millimeter wave.

9. 4. The distance measuring device according to claim 3, wherein the detection wave is a millimeter wave.

10. 5. The distance measuring device according to claim 4, wherein the detection wave is a millimeter wave.

11. 6. The distance measuring device according to claim 5, wherein the detection wave is a millimeter wave.

12. 3. The distance measuring device according to claim 1, which is installed in a container of various equipment, measures the distance to the object supplied to the container, and determines the amount of the object deposited in the container.

13. An operating method, comprising supplying the object to the container of each of the various facilities based on a measurement result obtained by the distance measuring device according to claim 12.

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