JP2010145249A - Ultrasonic measuring device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ultrasonic measuring device measuring a sea bottom shape continuously even under high-speed operation without obtaining six conditions of three-dimensional positions, roll, pitch and yaw of a hull. <P>SOLUTION: This ultrasonic measuring device includes: a transmitter for transmitting an ultrasonic wave having a different frequency in the azimuth direction; a receiver for receiving a reflected wave from an object of the ultrasonic wave transmitted from the transmitter;and a processing means for processing information of the reflected wave from the object as three-dimensional measurement results. The device also includes a connection means for connecting the three-dimensional measurement results successively. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an ultrasonic measurement apparatus, and more particularly to a measurement apparatus that enables continuous recognition of a wide-area situation such as the seabed with a simple apparatus configuration.

  Conventionally, a large number of fan-shaped ultrasonic beams are transmitted below the hull, and the reflected shape of the reflected wave of the transmitted ultrasonic beam and the data on the amount of movement of the hull are processed to provide a continuous seabed shape. A device for grasping the above is known.

  Further, as described in Patent Document 1, there is also known a measuring apparatus that can directly measure a three-dimensional space using a transmitter having different transmission directions depending on frequencies.

  The conventional measuring apparatus is thin in the YZ plane as shown in FIG. 14 (a), while the fan-shaped thin beam is in the XY plane as shown in FIG. 14 (b). 120 is formed and transmitted from the hull 2, and information on the shape of the seabed on a straight line in the X direction of the seabed 130 is measured by a reflected signal from the beam 120. Here, as shown in FIGS. 14 (a) and 14 (b), the rectangular coordinate system fixed to the hull is XYZ, the bow direction is the Z axis, the ship side direction is the X axis, and the ship bottom direction is the Y axis direction. And

  As shown in FIGS. 15A to 15C, the conventional measuring apparatus attached to the hull 2 can know the state of the seabed 130 together with the navigation time t of the hull 2. Yes. Here, as shown in FIG. 15C, the height of the seabed 130 is displayed by a hue or a contour line or other means so that it can be visually recognized.

  Next, the configuration of the conventional measuring apparatus 100 will be described.

  As shown in FIG. 16, a conventional measuring apparatus 100 includes a transmitter 110 that transmits ultrasonic waves 120 having different frequencies in the azimuth direction X, and converges the ultrasonic waves 120 only in a one-dimensional direction. A cylindrical acoustic lens 111 for irradiating a target 131 with a sound beam 121 and a reflected wave 122 from the target 131 are imaged as an object image on a received wave detection surface 142 divided in the Z-axis direction. A receiving acoustic lens 141.

  In addition, as shown in FIG. 17, the wave receiving detection surface 142 is divided in the Z-axis direction by arranging wave receiving elements 143 elongated in the azimuth direction X in the Z direction. Is forming.

  As described above, in the conventional measuring apparatus 100, the frequency of the fan-shaped ultrasonic beam 121 applied to the object 131 differs depending on the position in the azimuth direction X. Therefore, as shown in FIG. The position in the azimuth direction X can be known from the signal frequency component intensity at the output of each receiving element 143. On the other hand, the position in the Z direction can be known as the position of the wave receiving element 143 where the signal appears. Therefore, the two-dimensional shape of the object 131 can be known from these two pieces of position information.

  Further, the distance to the object 131 can be known from the propagation speed of the ultrasonic beam 121 and the round trip time from the transmission time to the reception time. Thus, the conventional measuring apparatus 100 can know the overall shape of the object 131 in the three-dimensional space in addition to the two-dimensional shape of the object 131.

JP 47-26160 A

  However, according to the configuration of the conventional measuring apparatus 100 described above, the radiation direction of the thin ultrasonic beam 121 transmitted in a sector shape in the azimuth direction X has three conditions of the hull 2 and six conditions of roll, pitch, and yaw. Therefore, in order to reduce the accuracy of the measurement position and obtain a more accurate measurement result, it is necessary to grasp all six conditions and correct the measurement result according to the grasped condition. There was a problem that became large scale.

  The conventional measuring apparatus 100 can be applied only to the case of measuring the shape of the object 131 in the observation field of view in the front (ZX plane) of the measuring apparatus, and can be applied to continuous measurement over a wide range. There was also a problem that it was not possible.

  Furthermore, the conventional measuring apparatus 100 has an ultrasonic wave propagation speed of about 1500 m / s. Therefore, if the water depth is 75 m, the transmitted ultrasonic wave is reflected by the object 131 and travels back and forth. 1 second is required. For this reason, in order to measure the seabed shape with an accuracy of 10 cm, the maximum operation speed of the hull 2 is limited to 10 cm / 0.1 s = 1 m / s (2 knots), and the work efficiency is extremely lowered. there were.

  Therefore, the present invention has been made in view of the above problems, and its purpose is to continuously maintain the shape of the seabed even under high-speed operation without grasping the three-dimensional position of the hull and the six conditions of roll, pitch, and yaw. It is a main subject to provide an ultrasonic measurement apparatus capable of measuring.

  An ultrasonic measurement apparatus according to the present invention includes a transmitter that transmits ultrasonic waves having different frequencies in the azimuth direction, and a receiver that receives a reflected wave from an object of the ultrasonic waves transmitted from the transmitter. An ultrasonic measurement apparatus comprising: a waver; and a processing unit that processes information on a reflected wave from the object as a three-dimensional measurement result, and includes a connecting unit that sequentially connects the three-dimensional measurement results. .

  In the ultrasonic measurement apparatus according to the present invention, the connection unit may include a determination unit that determines a feature point of the three-dimensional measurement result.

  In the ultrasonic measurement apparatus according to the present invention, it is preferable that the transmitter is arranged with polarization reversed.

  In the ultrasonic measurement apparatus according to the present invention, it is preferable that the connection unit includes a position information correction unit that corrects a connection result of a plurality of times using position information obtained from GPS.

  In the ultrasonic measurement apparatus according to the present invention, it is preferable that the connecting unit includes a roll angle correcting unit that corrects a result of the plurality of times of connection using roll angle information obtained from a detecting unit that detects the roll angle. .

  Since the ultrasonic measurement apparatus according to the present invention includes connection means for sequentially connecting the three-dimensional measurement results, the high-speed operation is possible without grasping the three-dimensional position of the hull and the six conditions of roll, pitch, and yaw. Can also continuously measure the seafloor shape.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments for carrying out the invention will be described with reference to the drawings. The following embodiments do not limit the invention according to each claim, and all combinations of features described in the embodiments are not necessarily essential to the solution means of the invention. .

  FIG. 1 is a schematic diagram illustrating the configuration of the ultrasonic measurement device according to the present embodiment, and FIG. 2 is a schematic diagram illustrating the configuration of the transmitter configuring the ultrasonic measurement device according to the present embodiment. FIG. 3 is a diagram for explaining the direction of the ultrasonic wave transmitted from the transmitter constituting the ultrasonic measurement apparatus according to the present embodiment, and FIG. 4 is an ultrasonic wave according to the present embodiment. FIG. 5 is a diagram for explaining the relationship between a drive signal applied to a transmitter constituting a measurement device and ultrasonic waves to be transmitted, and FIG. 5 is a diagram illustrating a transmission device constituting the ultrasonic measurement device according to the present embodiment. FIG. 6 is a diagram for explaining a single measurement method of the ultrasonic measurement device according to the present embodiment, and FIG. It is a figure for demonstrating the relationship with a measurement result, and FIG. 8 connects the measurement result measured with operation of a hull. FIG. 9 is a diagram for explaining the connecting means, FIG. 9 is a diagram showing the measurement result connected by the connecting means, and FIG. 10A shows that the connected measurement result has an error in the Y-axis direction. FIG. 10B is a diagram for explaining the result of correcting the coupled measurement result by the position information correcting means, and FIG. 11A is the coupled measurement result. FIG. 11B is a diagram for explaining that the result has an error in the X-axis direction, and FIG. 11B is a diagram for explaining the result of correcting the connected measurement result by the position information correcting unit. 12 is a diagram for explaining that the coupled measurement results have an inclined error, and FIG. 13 is a diagram for explaining a coupling method in the coupling means of the ultrasonic measurement device according to the present embodiment. It is.

  As shown in FIG. 1, the ultrasonic measurement apparatus 1 according to the present embodiment converges the ultrasonic wave only in a one-dimensional direction with a transmitter 10 that transmits ultrasonic waves having different frequencies in the azimuth direction X. As an object image, a cylindrical acoustic lens 11 for radiating the object 30 with the fan-shaped ultrasonic beam 21 and a wave detection surface 42 obtained by dividing the reflected wave 22 from the object 30 in the Z-axis direction. A receiving acoustic lens 41 that forms an image, a processing unit 50 that processes the formed object image as an image, and a connecting unit 51 that connects a plurality of measurement results image-processed by the processing unit 50 are provided. Yes.

  As shown in FIG. 2, the transmitter 10 constituting the ultrasonic measuring apparatus 1 according to the present embodiment is arranged by alternately inverting the polarization axes 15a and 15b of the piezoelectric element 15, and the Y-axis direction thereof is arranged. Are formed as an array transmitter in which a common electrode composed of a ground electrode 12 and a hot electrode 13 is formed on each of both end faces. When a drive signal 14 is applied between the ground electrode 12 and the hot electrode 13, the ultrasonic beam 21a can be transmitted in different directions according to the signal frequency.

  Next, the direction in which the ultrasonic beam 21a is transmitted will be described with reference to FIG.

  When a drive signal 14 is applied between the ground electrode 12 and the hot electrode 13 as shown in FIG. 3A, the drive signal 14 indicated by an arc as shown in FIG. A wavefront having a wavelength λ corresponding to the frequency of is formed and transmitted. Here, FIGS. 3 to 5 show a state in which waveforms having a phase difference of 180 degrees are transmitted between the solid line and the broken line. As apparent from FIG. 3A, the phases of adjacent wavefronts at the same time are inverted, so that the transmitted wavefront is canceled in the normal direction of the wavefront, and the radiation direction of the ultrasonic beam 21a. Is transmitted in a direction inclined by a radiation angle θ from a direction orthogonal to the arrangement direction of the piezoelectric elements 15.

  Here, when the frequency of the applied drive signal 14 is high, since the wavelength is short, as shown in FIG. 6A, the ultrasonic beam 21a is radiated in the vicinity of the front direction, while the drive signal When the frequency of 14 is low, the wavelength λ ′ increases, so that a wavefront is formed in a direction in which the radiation angle is further inclined as shown in FIG. Here, the radiation angle θ is given by Equation 1 from the pitch d of the piezoelectric elements 15, the frequency f of the drive signal 14, and the wavelength λ of the drive signal 14.

  Further, the long-distance sound field directivity characteristic R (θ) at this time is given by Equation 2.

  The transmitter 10 of the ultrasonic measurement apparatus 1 according to the present embodiment uses these relationships to scan the ultrasonic beam 21a in the azimuth direction X. As shown in FIG. By performing a frequency sweep by applying the drive signal 14 with a line, the ultrasonic beam 21a can be scanned in a fan shape. In FIG. 4, only the radiation direction of the ultrasonic beam 21a is shown, and the wavefront of the arc radiated from each piezoelectric element 15 is omitted.

  Further, in order to realize the spatial resolution of the entire transmission surface of the transmitter 10, the wavefronts from all the piezoelectric elements need to contribute, and as shown in FIG. 4, the total number of piezoelectric elements (because the phase is inverted). A drive signal 14 having a half wave number (five periods in FIG. 4) is required.

  Further, the transmitter 10 is divided and formed as partial apertures 13a and 13b, and short drive signals 14a and 14b having a time difference T are applied to the partial apertures 13a and 13b, respectively, in the direction of the ultrasonic beam 21a. You may form so that a short ultrasonic signal may be transmitted and high distance resolution may be implement | achieved.

  In this way, if transmission with different frequencies in the azimuth direction is performed, the azimuth X can be known from the frequency of the reflected wave. For example, by transmitting a waveform whose frequency changes with time or broadband noise, All three-dimensional space can be measured by one ultrasonic propagation time.

  Next, with reference to FIG.6 and FIG.7, the measuring method of the ultrasonic measuring device 1 which concerns on this embodiment is demonstrated.

  As shown in FIGS. 6A and 6B, the ultrasonic measurement apparatus 1 according to the present embodiment is installed in the hull 2 and emits an ultrasonic beam 21 from the bottom of the hull 2 toward the object 30 on the seabed. A measurement result as shown in FIG. 6C can be obtained by transmitting and receiving the reflected wave.

  Here, when the viewing angle α from the ship bottom is about 30 degrees as shown in FIG. 6B, the length of one side of the measurement result in FIG. 6C is half of the water depth. For example, at a water depth of 100 m, it is possible to obtain a one-time measurement result in which the seabed condition of a side of 50 m is depicted three-dimensionally including the degree of unevenness. Here, since the time required for measurement is short, the measurement result of one time can show an accurate three-dimensional shape of the seabed without being affected by geometric distortion caused by fluctuation of the hull 2 or the like.

  Here, the measurement result shown in FIG. 6C is correct as the sea bottom shape, but is based on the hull coordinate system (xyz) indicating the relative positional relationship from the hull 2. It does not correspond to the coordinate system fixed on the ground surface like the Japanese geodetic system. Hereinafter, a rectangular coordinate system fixed to the ground surface, such as the Japanese geodetic system (reference ellipsoidal coordinate system), is expressed as XYZ.

  As shown in FIG. 6, when executed at each of the positions a, b and c in FIG. 7, if the hull 2 is accurately performing a uniform linear motion, the measurement results 60a, 60b and 60c are obtained at each position. Can be obtained as These measurement results 60a, 60b, and 60c are correct seabed conditions in the hull coordinate system.

  Next, the processing method of the connection means 51 of the ultrasonic measurement apparatus 1 according to the present embodiment will be described with reference to FIGS.

  As described above, the measurement results 60a, 60b, and 60c shown in FIG. 7 represent the correct seabed condition in the hull coordinate system. However, the navigation of the hull 2 is different from the constant-velocity linear motion in various ways. It varies depending on factors. Here, generally, since two congruent three-dimensional structures are linear and three points coincide with each other, they overlap as a whole. Therefore, the measurement results 60a, 60b, and 60c in FIG. 7 are shown in FIG. The feature points 70a, 70b, and 70c in the measurement result 60a and the feature points 70a ′, 70b ′, and 70c ′ in the measurement result 60b are overlapped. Similarly, the feature points 70d, 70e, and 70f in the measurement result 60b, and the measurement result 60c. By overlapping the feature points 70d ', 70e', and 70f ', the position of the hull 2 can be connected to the rectangular coordinate system XYZ fixed to the ground surface.

  Here, the feature points 70a, 70b, and 70c of the measurement result 60a are selected and determined by the determination unit included in the connection unit 51 so that the three points do not line up in a straight line. The feature points 70a ′, 70b ′, and 70c ′ of the measurement result 60b are determined so as to be congruent with the feature points of the measurement result 60a.

  The measurement result 61 connected by the connecting means 51 is obtained as shown in FIG. 9, and is connected as a correct wide-area seabed shape. Thus, since the ultrasonic measurement apparatus 1 according to the present embodiment does not require information on the hull position, even when the hull 2 is shaken, the ultrasonic measurement apparatus 1 is fixed to the ground surface without being affected by the shake. It is possible to obtain a measurement result connected and displayed as a correct seabed shape on the rectangular coordinate system XYZ.

  Next, a method for correcting the measurement result 61 connected by the connecting means 51 will be described with reference to FIGS.

  As shown in FIG. 9, when the measurement result 61 is connected and displayed, the position information of the hull 2 is estimated in time series. Here, when the measurement result 61 has a bias error due to an apparatus error or the like, all the measurement results 60a, 60b, and 60c are connected in an inclined manner on a rectangular coordinate system fixed on the ground surface of the estimated hull 2. The position of the Y coordinate in is gradually displayed shallower as shown in FIG.

  Therefore, the position of the hull 2 in the Y-coordinate direction is confirmed by a GPS signal or the like for each of the multiple connection processes, and the average error in the pitch angle direction is corrected by the position information processing means. In this way, the Y coordinate of the position of the hull 2 is corrected by the position information processing means, and as shown in FIG. 10 (b), it becomes horizontal and accurate continuous measurement of the seabed depth on the ground surface coordinates can be performed. It has become.

  Similarly, when errors are accumulated in the connection process at the position in the horizontal plane (ZX plane), the estimated position of the ZX coordinate of the hull 2 is as shown in FIG. This is different from the actual horizontal plane position. Accordingly, by correcting the Z-X coordinates on average by the position information correction means with more reliable information by GPS or the like, a more accurate topographic map on the ground surface coordinates as shown in FIG. Can be completed.

  Furthermore, as shown in FIG. 12, when measurement is started in a situation where the hull 2 is rolling, all measurement results 60a, 60b, and 60c are inclined. As for the roll angle, since the correction method based on the accumulated error in the measurement results as described above cannot be used, the hull 2 is equipped with detection means for measuring the roll angle β of the hull 2 and the horizontal check is performed. . And based on the roll angle information obtained by this detection means, it is possible to correct the measurement result by the roll angle correction means and perform accurate continuous measurement on the ground surface coordinates.

  Next, a method for connecting the measurement results 60a, 60b, and 60c will be described with reference to FIG. In FIG. 13, the case where the feature points 70a, 70b, and 70c are overlapped with the feature points 70a ′, 70b ′, and 70c ′ will be described.

  As shown in FIG. 13, first, an arbitrary point of the measurement result 60a (in this embodiment, a feature point 70a) and a corresponding feature point of the measurement result 60b (in this embodiment, a feature point 70a ′) Are translated by the vector 70a70a ′, and the triangle 70a70b70c is defined as a triangle 70a′70b170c1. Thereafter, in order to make the vertex 70b1 coincide with 70b ′, the coordinate axis is rotated by an angle φ1 around the vertex 70a ′, and the triangle 70a′70b170c1 is changed to a triangle 70a′70b′70c2. Then, in order to make the vertex 70c2 coincide with 70c ′, the coordinate axis is rotated by an angle φ2 about the line segment 70a′70b ′, and the triangle 70a′70b′70c2 is changed to the triangle 70a′70b′70c ′. The result 60a and the measurement result 60b are superimposed. By these three types of coordinate transformations, the origin also moves simultaneously, indicating the position of the new hull 2.

  The ultrasonic measuring apparatus 1 configured in this way can perform continuous measurement of the seabed shape even under high-speed operation without grasping the three-dimensional position of the hull and the six conditions of roll, pitch, and yaw.

It is the schematic explaining the structure of the ultrasonic measuring device which concerns on this embodiment. It is the schematic explaining the structure of the transmitter which comprises the ultrasonic measuring device which concerns on this embodiment. It is a figure for demonstrating the direction of the ultrasonic wave transmitted from the transmitter which comprises the ultrasonic measuring device which concerns on this embodiment. It is a figure for demonstrating the relationship between the drive signal applied to the transmitter which comprises the ultrasonic measuring device which concerns on this embodiment, and the ultrasonic wave transmitted. It is a figure for demonstrating another form of the transmitter which comprises the ultrasonic measuring device which concerns on this embodiment. It is a figure for demonstrating the measurement method of the ultrasonic measurement apparatus concerning this embodiment once. It is a figure for demonstrating the relationship between operation of a hull, and a measurement result. It is a figure for demonstrating the connection means which connects the measurement result measured with operation of a hull. It is a figure which shows the measurement result connected by the connection means. FIG. 4A is a diagram for explaining that the connected measurement results have an error in the Y-axis direction, and FIG. 4B is a diagram for explaining the results of correcting the linked measurement results by the position information correcting means. . FIG. 4A is a diagram for explaining that the connected measurement results have an error in the X-axis direction, and FIG. 4B is a diagram for explaining the results of correcting the linked measurement results by the position information correcting means. . It is a figure for demonstrating that the connected measurement result has the error which inclined. It is a figure for demonstrating the connection method in the connection means of the ultrasonic measuring device which concerns on this embodiment. It is the schematic for demonstrating the conventional measuring method. It is the schematic which shows the conventional measurement result. It is the schematic for demonstrating the structure of the conventional measuring device. It is a figure for demonstrating the structure of the received wave detection surface of the conventional measuring device.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Ultrasonic measuring device, 2 Hull, 10 Transmitter, 11 Transmitting acoustic lens, 12 Ground electrode, 13 Hot electrode, 14 Drive signal, 15 Piezoelectric element, 15a, 15b Polarization axis, 21 Ultrasonic beam, 22 Reflection Wave, 30 object, 41 receiving acoustic lens, 42 receiving detection surface, 50 processing means, 51 connecting means, 70a, 70b, 70c, 70d, 70e, 70f, 70a ′, 70b ′, 70c ′, 70d ′, 70e ', 70f' Features, θ radiation angle, d piezoelectric element pitch, f drive frequency, λ wavelength, T signal time difference, α viewing angle, β roll angle

Claims (5)

A transmitter for transmitting ultrasonic waves having different frequencies in the azimuth direction;
A receiver for receiving a reflected wave from an object of ultrasonic waves transmitted from the transmitter;
In an ultrasonic measurement apparatus comprising processing means for processing reflected wave information from the object as a three-dimensional measurement result,
An ultrasonic measurement apparatus comprising a connecting means for sequentially connecting the three-dimensional measurement results. The ultrasonic measurement device according to claim 1,
The ultrasonic measurement apparatus, wherein the connection unit includes a determination unit that determines a feature point of the three-dimensional measurement result. In the ultrasonic measuring device according to claim 1 or 2,
The ultrasonic measuring apparatus, wherein the transmitter is arranged with polarization reversed. In the ultrasonic measuring device according to any one of claims 1 to 3,
The ultrasonic measurement apparatus, wherein the connection unit includes a position information correction unit that corrects a connection result of a plurality of times based on position information obtained from GPS. In the ultrasonic measuring device according to any one of claims 1 to 4,
The ultrasonic measuring apparatus according to claim 1, wherein the connecting unit includes a roll angle correcting unit that corrects a result of connecting a plurality of times based on roll angle information obtained from a detecting unit that detects a roll angle.

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