JP4791011B2 - Ultrasonic transmitter, ultrasonic transmitter and receiver, and detector using the same - Google Patents

Description

  In the present invention, a transmission beam of an ultrasonic signal having directivity in a predetermined direction within a predetermined detection area is formed and transmitted to the detection area, a reflected signal from a target in the detection area is received, and a reception beam is received. The present invention relates to an ultrasonic transducer to be formed, and a detection device that includes the ultrasonic transducer and detects a target in a detection area.

  Conventionally, tidal current meters, Doppler sonars, and multidirectional fish finders use ultrasonic transducers that form pencil beams in multiple directions in order to detect multiple directions with respect to the ship. As such a conventional ultrasonic transducer, an ultrasonic transducer or a plurality of transducers arranged in a tilted manner in the observation direction to be detected is detected, such as a plurality of flat plate transducers corresponding to the number of observation directions. Phased array type ultrasonic transducers arranged in a cylindrical or spherical shape have been devised. However, in an ultrasonic transducer using a flat plate vibrator, the transducer itself becomes large and the beam direction cannot be varied. Moreover, in a phased array type ultrasonic transducer, the transducer itself is small, but a transducer circuit is required for each transducer. Therefore, the transceiver circuit is complicated, the circuit scale is large, and the cost is increased. End up.

In order to solve these problems, transducers have been devised that form transducers in a specific direction by arranging transducers in a specific linear direction and controlling the signals that drive these transducers. A beam can be formed only in the direction of the vertical plane including the arrangement direction of the children. For this reason, an ultrasonic transducer has been devised in which transducers are two-dimensionally formed and beams are formed in a plurality of directions by controlling drive signals of these transducers (see, for example, Patent Document 1). ).
JP 2000-147095 A

  However, in the ultrasonic transmitter / receiver described in Patent Document 1, detection in six directions shifted by an angle π / 3 in the horizontal direction, for example, bow direction, starboard front, starboard rear, stern direction, port rear, port front To do this, 2 channels are required for transmission and 12 channels are required for reception. That is, a wiring pattern for at least 14 channels is required. For this reason, the pattern of the transmission / reception circuit board becomes complicated, and even if the flat array itself is small, the circuit scale of the transmission / reception circuit becomes large, which becomes a problem when the apparatus is downsized. In addition, since signals for 12 channels are processed to detect six directions, signal processing becomes complicated.

  An object of the present invention is to form a transmission beam and a reception beam in a plurality of predetermined directions with a smaller number of channel configurations, to form a miniaturized ultrasonic transducer with a simple structure, and to provide this ultrasonic transducer It is intended to constitute a small detection device.

Ultrasonic transmitters of the invention consists of nine channels of the transducer array in which a plurality of transducers, each a plan transducer array in which all the transducers are arranged and formed in a regular triangle lattice pattern ,
In the transducer array, the distance between the centers of adjacent transducers is a length (2/3 ^1/2 ) d,
The first channel vibrator, the second channel vibrator, and the third channel vibrator are adjacent to each other in the shape of an equilateral triangle having a distance (2/3 ^1/2 ) d between the centers of the vibrators. The first group and the fourth channel vibrator, the fifth channel vibrator, and the sixth channel vibrator are positively set with the distance between the centers of each vibrator being a length (2/3 ^1/2 ) d. The second group formed adjacent to each other in a triangular shape, the seventh channel vibrator, the eighth channel vibrator, and the ninth channel vibrator are set to have a center-to-center distance of each vibrator (2/3 ^{1 / 2} ) A third group is formed adjacent to the equilateral triangular shape d.
The position and orientation of the second and third channel vibrators with respect to the first channel vibrator, the position and orientation of the fifth and sixth channel vibrators with respect to the fourth channel vibrator, The positions and orientations of the eighth and ninth channel vibrators with respect to the seven channel vibrators are in agreement with each other,
A plane transducer array in which the first group, the second group, and the third group are repeated in a pattern that is formed in a regular triangle shape with the distance between the centers of each group being 2d;
By applying a transmission drive signal having a predetermined phase relationship to the transducer of each channel of the planar transducer array, the transmission beam in a direction perpendicular to the transducer array surface of the planar transducer array, or the vertical 6 directions of transmission beams whose angle projected onto the transducer array surface radially with respect to the transmission beam in the direction is π / 3, or radially on the transducer array surface with respect to the transmission beam in the vertical direction Transmitting beam forming means for forming a transmitting beam in three directions with a projected angle of 2π / 3 is provided.

  In this configuration, by performing the phase control on the transducer of each channel, a plurality of equiphase surfaces are formed in a predetermined plurality of directions, and a transmission beam is formed. At this time, a transmission beam for transmission in seven directions is simultaneously provided by applying transmission drive signals for forming an equiphase surface in seven directions of six directions that form an angle of π / 3 and one direction perpendicular to the transducer surface. Is formed. Further, a transmission drive signal having a plane parallel to the transducer array plane as an equiphase plane, and a direction perpendicular to the three directions in which the angle formed between the six directions is 2π / 3 is defined as an equiphase plane. The transmission drive signal to be transmitted and the transmission drive signal having an equiphase surface in the direction perpendicular to the three directions where the angle formed between the three directions different from the three directions out of the six directions is 2π / 3, are sequentially applied to each channel. By performing phase control on these transducers, two different transmission beams in three directions and a transmission beam in one direction perpendicular to the transducer surface are individually formed. At this time, the transmission signal intensity is increased by reducing the number of beams transmitted simultaneously.

In addition, the ultrasonic transmitter of the present invention is specifically a transducer array in which the first channel transducer, the second channel transducer, and the third channel transducer are centered between the transducers. A first group adjacent to each other in an equilateral triangle shape having a length (2/3 ^1/2 ) d, a fourth channel vibrator, a fifth channel vibrator, and a sixth channel vibrator. A second group adjacent to each other in an equilateral triangle having a distance between the centers of the vibrators of length (2/3 ^1/2 ) d, a seventh channel vibrator, an eighth channel vibrator, and a ninth A third group of channel oscillators adjacent to each other in the form of an equilateral triangle having a distance (2/3 ^1/2 ) d between the centers of the respective oscillators. 2. 3rd channel transducer position and orientation and 4th channel transducer The position and orientation of the fifth and sixth channel vibrators and the position and orientation of the eighth and ninth channel vibrators with respect to the seventh channel vibrator are in agreement with each other. A plane transducer array in which a group and a third group are repeated in a pattern composed of an equilateral triangle having a center-to-center distance of each group of length 2d, and the phase of each group in the transducers of the plane transducer array 2π / 3 rad. Transmission beam forming means for giving different transmission drive signals to each other, or giving transmission drive signals of the same phase to all groups.

In this configuration, the distance between the center of the transducer group of the first channel arranged in the direction perpendicular to the specific direction, the center of the second group, and the direction of the third group parallel to the specific direction is the distance between the centers of the transducers. The distance d is (2/3 ^1/2 ) d. For groups arranged at an interval d parallel to the specific direction, 2π / 3 rad. A transmission drive signal having a phase difference of is applied.
FIG. 24 is a diagram showing the relationship between the phase of the drive signal applied to the transducers arranged in a specific direction and the transmission beam. FIG. 24A shows the range from the leftmost transducer 101 to the rightmost transducer 104. In order, the phase is 2π / 3 rad. (B) shows the phase in the order of -2π / 3 rad. From the leftmost vibrator 101 to the rightmost vibrator 104. When the phase is shifted one by one, the phase is 2π / 3 rad. In order from the vibrator 104 at the right end to the vibrator 101 at the left end. The case of shifting each is shown.

As shown in FIG. 24, when the transducers are arranged at an interval d with respect to a specific direction (arrangement direction), the interval D of the equiphase surfaces of the ultrasonic waves generated from the transducers is equal to the arrangement direction of the transducers. If the angle made with the phase plane is θ,
D = d · sin θ.
Further, 2π / 3 rad. When the phase difference is provided, the interval D between the equiphase surfaces is λ as the wavelength of the ultrasonic signal.
D = λ / 3.
Therefore, d · sin θ = λ / 3 Formula (1)
The relationship holds.

For this reason, in order to form a transmission beam in a desired direction, the frequency (wavelength) of the ultrasonic signal and the interval d between the transducers may be set as described above.
That is, by applying a transmission drive signal of a desired frequency to each transducer so as to have the above phase relationship, a transmission beam is formed that is parallel to a specific direction and has a direction of an angle θ with respect to a horizontal plane as a traveling direction. Can do. Then, by changing the direction in which the phase is advanced, the traveling direction of the transmission beam with respect to the specific direction is changed to π rad. It can be changed (180 °), ie in the opposite direction.

  Here, in the configuration described above, as shown in FIG. 5, the angle formed by the first group of transducers, the second group of transducers, and the third group of transducers is 2π / 3 rad. In the three directions, the relationship described above, that is, the relationship arranged at the interval d along the specific direction, the direction having a predetermined angle with respect to the vertical downward direction in the direction parallel to these directions. A transmission beam having a traveling direction is formed. Then, as shown in FIGS. 6 (a) and 7 (a), by reversing the direction of phase control (direction in which the phase proceeds), respectively, in FIGS. 6 (b) and 7 (b), respectively. 2π / 3 rad. A transmission beam in three directions having an angle of 5 is formed, and a transmission beam in six directions is formed in total. Furthermore, by applying a transmission drive signal having the same phase to the transducers of all channels, the equiphase surface becomes the vertical direction (direction perpendicular to the horizontal direction), and a transmission beam having this direction as the traveling direction is formed. . That is, in the above-described three groups each including three channels, transmission beams in seven directions are formed substantially simultaneously in a time division manner with a nine-channel configuration.

The ultrasonic wave transmitter according to the present invention is specifically a transducer array in which the distance between the centers of adjacent transducers is a length (2/3 ^1/2 ) d, and the first channel transducer A first group in which the second channel vibrator and the third channel vibrator are adjacent to each other in an equilateral triangle shape with a distance (2/3 ^1/2 ) d between the centers of the vibrators; The fourth channel transducer, the fifth channel transducer, and the sixth channel transducer are adjacent to each other in the shape of an equilateral triangle having a distance (2/3 ^1/2 ) d between the centers of the transducers. The second group, the seventh channel transducer, the eighth channel transducer, and the ninth channel transducer are equilateral triangles with the center-to-center distance of each transducer being the length (2/3 ^1/2 ) d. A third group is formed adjacent to the shape, and the second and third channels for the vibrator of the first channel are formed. Position and orientation of the transducer of the channel, positions and orientations of the fifth and sixth channel transducers with respect to the fourth channel transducer, and positions of the eighth and ninth channel transducers with respect to the seventh channel transducer. A planar transducer array in which the orientations coincide with each other and the first group, the second group, and the third group are repeated in a pattern that is formed in an equilateral triangle shape with the distance between the centers of each group being 2d. In-phase transmission drive signals are applied to the first channel transducer, the fourth channel transducer, and the seventh channel transducer, and the second channel transducer, the fifth channel transducer, and the eighth channel transducer In each of the vibrators, 2π / 3 rad. A transmission drive signal whose phase is advanced step by step is applied to each of the third channel transducer, the ninth channel transducer, and the sixth channel transducer in this order. Transmission beam forming means for providing a transmission drive signal whose phase advances step by step.

  In this configuration, the first channel vibrator, the fourth channel vibrator, and the seventh channel vibrator each have an angle of 2π / 3 rad. Since the transmission drive signals having the same phase are applied to the three directions, the transmission beams formed from the transducers of these channels are directed in the direction perpendicular to the horizontal direction. Further, the angle formed by the second channel vibrator, the fifth channel vibrator, and the eighth channel vibrator on the horizontal plane is 2π / 3 rad. Are arranged at intervals of 2d with respect to the three directions, and a phase difference of 2π / 3 rad. Since each transmission drive signal is applied, the angle between them is 2π / 3 rad. A transmission beam in three directions is formed. The angle formed by the third channel vibrator, the sixth channel vibrator, and the ninth channel vibrator is 2π / 3 rad. Are arranged at intervals of 2d with respect to the three directions, and a phase difference of 2π / 3 rad. Since each transmission drive signal is applied, the angle between them is 2π / 3 rad. Thus, a transmission beam in three directions different from the transmission beam formed from the transducers of the second, fifth, and eighth channels is configured. That is, a transmission beam is formed simultaneously in seven directions.

  In addition, an ultrasonic transducer of the present invention includes the above-described ultrasonic transducer, and includes three channels arranged in a direction perpendicular to the first specific direction of the planar transducer array in a first specific direction. With respect to three groups adjacent in the parallel direction, the phase of the received signal of each group is sequentially 2π / 3 rad. The first phase control to be advanced step by step, and 2π / 3 rad. In a predetermined rotation direction with respect to the first specific direction. The three groups adjacent to each other in the direction parallel to the second specific direction, which are composed of three channels arranged in a direction perpendicular to the second specific direction, are arranged in order along the second specific direction. The phase of the received signal of the group of 2π / 3 rad. Second phase control to be advanced step by step, and 2π / 3 rad. For each of the first specific direction and the second specific direction. For three groups adjacent to each other in a direction parallel to the third specific direction, each of which is composed of three channels arranged in a direction perpendicular to the third specific direction at an angle of, respectively, along the third specific direction. The phase of the received signal of the group of 2π / 3 rad. It is characterized in that a reception beam forming means for simultaneously performing the third phase control to be advanced step by step is provided.

  In this configuration, the phase of a group of three rows each having three channels arranged in a direction perpendicular to a specific direction is set to 2π / 3 rad. By performing the shift control, the component in the specific direction of the signal received by the transducer of each channel is extracted, and the reception beam in the specific direction is formed. This specific direction is 2π / 3 rad. It exists in three directions with an angle between For this reason, the reception beams in the three directions are simultaneously formed by controlling the phase of the reception signal received by each channel in each specific direction.

  In addition, an ultrasonic transducer of the present invention includes the above-described ultrasonic transducer, and includes three channels arranged in a direction perpendicular to the first specific direction of the planar transducer array in a first specific direction. With respect to three groups adjacent in the parallel direction, the phase of the received signal of each group is sequentially 2π / 3 rad. First phase control for advancing step by step, and the phase of the received signal of each group in order along a fourth specific direction opposite to the first specific direction by 2π / 3 rad. 4th phase control to advance step by step, and 2π / 3 rad. In a predetermined rotation direction with respect to the first specific direction. The three groups adjacent to each other in the direction parallel to the second specific direction, which are composed of three channels arranged in a direction perpendicular to the second specific direction, are arranged in order along the second specific direction. The phase of the received signal of the group of 2π / 3 rad. Second phase control for advancing step by step, and the phase of the received signal of each group in order along the fifth specific direction opposite to the second specific direction is 2π / 3 rad. For each of the fifth specific phase and the first specific direction and the second specific direction. For three groups adjacent to each other in a direction parallel to the third specific direction, each of which is composed of three channels arranged in a direction perpendicular to the third specific direction at an angle of, respectively, along the third specific direction. The phase of the received signal of the group of 2π / 3 rad. Third phase control for advancing step by step, and the phase of the received signal of each group in order along the sixth specific direction opposite to the third specific direction is 2π / 3 rad. A reception beam forming means for simultaneously performing the sixth phase control to be advanced step by step is provided.

  In this configuration, the phase of a group of three rows each having three channels arranged in a direction perpendicular to a specific direction is set to 2π / 3 rad. By performing the shift control, the component in the specific direction of the signal received by the transducer of each channel is extracted, and the reception beam in the specific direction is formed. This specific direction is determined by π / 3 rad. 6 directions having an angle formed by each other, in other words, the angle πrad. The angle 2π / 3 rad. Which two specific directions which have a relationship of (reverse direction) make, respectively. There are three pairs. Therefore, the reception beams in the six directions are simultaneously formed by controlling the phase of the reception signal received by each channel in each specific direction.

  In addition, the ultrasonic transducer of the present invention is characterized by having in-phase control for making the received signals of all the channels the same phase, and performing the in-phase control at the same time.

  In this configuration, the reception signals received by the respective channels are phase-controlled in the same phase, so that reception beams in the direction perpendicular to the horizontal plane (the plane having the six directions) are simultaneously formed.

  The reception beam forming means of the ultrasonic transducer of the present invention includes a first reception control for simultaneously performing the first phase control, the second phase control, and the third phase control, and a fourth phase control. And a second reception control for simultaneously performing the fifth phase control and the sixth phase control, wherein at least one of the first reception control and the second reception control is executed.

  In this configuration, since the directions of the reception beams are three directions that form an angle of 2π / 3, the amount of data of the reception beams is reduced, and the time for data processing is reduced. That is, the received beam data is simplified, data processing is facilitated, and the speed is increased.

  In addition, the detection device of the present invention is characterized by comprising the above-described ultrasonic transducer and a control means for controlling the transmission drive signal and generating detection data based on the reception beam composed of the reception signal. .

  In this configuration, the above-described ultrasonic transducer is used to control a 9-channel transducer, and at the time of transmission, a transmission beam having a predetermined angle θ with respect to the vertical downward direction is substantially simultaneously or simultaneously in a time division manner. Angle π / 3 rad. Are formed in 6 directions, and a vertically downward transmission beam is formed to form a total of 7 transmission beams. At the time of reception, a reception beam is simultaneously formed in the seven directions corresponding to the direction of the transmission beam, and the surrounding situation is detected.

  According to the present invention, it is possible to configure an ultrasonic transducer that can transmit and receive simultaneously in seven directions while having a simple structure.

  Further, according to the present invention, an ultrasonic wave transmitter / receiver with high transmission intensity can be configured by setting the simultaneous transmission direction to three directions among the above-mentioned seven directions.

An ultrasonic transducer according to an embodiment of the present invention and a detection apparatus including the ultrasonic transducer will be described with reference to the drawings. In this description, an underwater detection device that detects underwater will be described as an example of the detection device.
FIG. 1 is a block diagram showing a schematic configuration of a detection apparatus provided with an ultrasonic transducer 1 of the present invention.
As shown in FIG. 1, the detection device of the present invention forms a transmission beam of an ultrasonic signal having a predetermined directivity with respect to a predetermined area in water, transmits the detection area, and transmits it to a target in the area. An ultrasonic transducer 1 that receives the reflected signal reflected to form a reception beam, a control circuit 6 that provides a drive control signal to the ultrasonic transducer 1, and detection image data from the received data in each direction. An image processing circuit 7 (corresponding to “detection data generating means” of the present invention) that is generated and output to the display 8, a band-pass filter (BPF) 70, and a display 8 that displays an image based on the display image data. It consists of and.

The ultrasonic transmitter / receiver 1 has a plane parallel to a horizontal plane as a main surface and is installed on the ship bottom, a 9-channel planar transducer array 2, a transmission / reception switch 3 that switches between transmission and reception of the planar vibration array 2, A transmission drive signal generation circuit 4 for generating a transmission drive signal to be given to each transducer of the planar transducer array 2 and a reception beam are formed on the basis of reception signals from each transducer of the planar transducer array 2, and each direction And a reception beam forming circuit 5 for outputting reception data. The transmission drive signal generation circuit 4 and the transmission / reception wave switching unit 3 are connected by a three-channel bus line via the transmission amplifier 40, and the transmission / reception wave switching unit 3 and the planar transducer array 2 are planar transducers. The 9-channel bus lines corresponding to the number of channels of the array 2 are connected, and the transmission / reception switch 3 and the reception beam forming circuit 5 are connected via the reception amplifier 50 via the 9-channel bus lines. The transmission / reception switching device 3 switches between transmitting an ultrasonic signal by the transducer of the planar transducer array 2 or receiving a reflected signal based on a timing signal given from the control circuit 6, and is input to the three channels. Are transmitted to the set channels of the 9-channel transducers of the planar transducer array 2, respectively. On the other hand, the transmission / reception switch 3 outputs the reception signals of 9 channels from the planar transducer array 2 to the reception beam forming circuit 5 as they are. A correspondence relationship is set in advance between the three channels of the bus line between the transmission drive signal generation circuit 4 and the transmission / reception switch 3 and the nine channels of the bus line between the transmission / reception switch 3 and the plane transducer array 2. Similarly, a correspondence relationship is set in advance for the nine channels of the bus line between the planar transducer array 2 and the transmission / reception switch 3 and the nine channels of the bus line between the transmission / reception switch 3 and the reception beam forming circuit 5. Yes. The transmission drive signal generation circuit 4 generates a drive signal to be given to each transducer based on the drive control signal input from the control circuit 6 so that a transmission beam having a desired directivity is formed, and phase control to be described later And the like are outputted to each transducer constituting the planar transducer array 2 via the transmission / reception switch 3. The reception beam forming circuit 5 inputs the reflected signal received by each transducer constituting the planar transducer array 2 via the transmission / reception switch 3 and performs phase control processing described later to cope with the transmission beam. A reception beam having a predetermined directivity is formed and output. The reception beam output from the reception beam forming circuit 5 is input to the image processing circuit 7 via a band pass filter (BPF) 70. Here, the BPF 70 passes only a predetermined frequency band component of the reception beam. Thereby, the reception beam has a predetermined tilt angle. In other words, a reception beam having a predetermined tilt angle is formed. The image processing circuit 7 generates detection image data in a format according to the specification of the display 8 based on the received beam having the predetermined tilt angle, and outputs the detected image data to the display 8.
Here, the transmission drive signal generation circuit 4, the transmission amplifier 40, and the transmission / reception wave switch 3 correspond to the “transmission beam forming means” of the present invention, and the control circuit 6, the transmission drive signal generation circuit 4, the transmission amplifier 40, the transmission / reception unit The wave switch 3 and the planar transducer array 2 correspond to the “ultrasonic wave transmitter” of the present invention.

Next, the configuration of the planar transducer array 2 will be described with reference to FIGS. 2, 3, and 4. FIG.
2A and 2B show the configuration of the planar transducer array 2, wherein FIG. 2A is a plan view of the ultrasonic signal transmission surface (plan view of the bottom of the ship viewed from the water), and FIG. 2B is AA ′ in FIG. It is sectional drawing. A number in a circle representing the vibrator indicates a channel number.
3 is a diagram showing the positional relationship of each transducer of the planar transducer array 2 shown in FIG. 2, wherein (a) is a plan view and (b) is a partially enlarged plan view thereof.
4 is a configuration diagram showing a wiring pattern of the planar vibrator array 2 shown in FIG. Although channel numbers are omitted in FIGS. 3A and 4, the arrangement of the vibrators is the same as that shown in FIG.

As shown in the figure, the plane transducer array 2 has a side perpendicular to the bow-stern direction and an angle formed with respect to this side by π / 3 rad. Is an equilateral triangle lattice structure (see FIG. 3A) having an equilateral triangle having two sides as a basic configuration, and the vibrator 100 (100a to 100c, 100e to 100j) is located at the apex position of the equilateral triangle. is set up. The length of one side of the equilateral triangle, that is, the center-to-center distance (2/3 ^1/2 ) d in the transducer 100 and the spacing d between the transducer arrays are based on the above-described equation (1). It is set in advance by λ and a tilt angle θ which is an angle formed by the vertically downward direction and the detection direction. For example, the wavelength λ of the transmission signal is 15 mm (frequency is 100 kHz), and the tilt angle θ is π / 6 rad. When it is desired to set (30 °), the distance d between the transducer arrays is set to 10 mm.

  The vibrator 100 is divided into nine channels, and the vibrators 100a to 100c and 100e to 100j of the respective channels are arranged in the relationship shown in FIGS. In FIGS. 2A and 3B, symbols are given only to the transducers represented by each channel, and only the channel numbers to which the other transducers belong are shown. Further, in the following description, the transducers belonging to each channel are referred to as n-th channel transducers with the channel number to which they belong as the head (n is the channel number).

As shown in FIG. 3B, equilateral triangles having a side length of (2/3 ^1/2 ) d with the centers of the first, second, and third channel vibrators 100a to 100c as vertices are formed. The side connecting the second and third channel vibrators 100b and 100c is perpendicular to the bow-stern direction, and the first channel vibrator 100a is disposed on the bow side with respect to this side. The fourth channel vibrator 100e is disposed at a position symmetrical to the second channel vibrator 100b with respect to the third channel vibrator 100c, and the fifth channel vibrator 100f is first with respect to the third channel vibrator 100c. It is arranged at a position symmetrical to the channel vibrator 100a. The sixth channel vibrator 100g is arranged at a position that forms an equilateral triangle having a side length of (2/3 ^1/2 ) d together with the fourth channel vibrator 100e and the fifth channel vibrator 100f, in other words. The sixth channel vibrator 100g is disposed at a position symmetrical to the third channel vibrator 100c with the line connecting the fourth and fifth channel vibrators 100e and 100f as a line symmetry reference. The seventh channel vibrator 100h is disposed at a position symmetrical to the fifth channel vibrator 100f with respect to the sixth channel vibrator 100g, and the eighth channel vibrator 100i is fourth with respect to the sixth channel vibrator 100g. It is arranged at a position symmetrical to the channel vibrator 100e. The ninth channel vibrator 100j is arranged at a position that forms an equilateral triangle with a side length of (2/3 ^1/2 ) d together with the seventh channel vibrator 100h and the eighth channel vibrator 100i, in other words. The ninth channel vibrator 100j is arranged at a position symmetrical to the sixth channel vibrator 100g with the line connecting the seventh and eighth channel vibrators 100h and 100i as a line symmetry reference. At the same time, the ninth channel vibrator 100j forms an equilateral triangle with one side length of (2/3 ^1/2 ) d with the first and second channel vibrators 100a and 100b, The fourth channel vibrators 100b and 100e are arranged at positions that form an equilateral triangle having a side length of (2/3 ^1/2 ) d. The planar transducer array 2 is formed by repeating such a basic configuration in a predetermined pattern.

  The planar vibrator array 2 having such a configuration is formed by a substrate having a piezoelectric effect made of a ferroelectric or the like and electrodes formed at opposing positions on both surfaces of the substrate. For example, as shown in FIG. 2B, the vibrators 100f to 100h are formed by arranging electrodes 102 at positions facing each other on both surfaces of the piezoelectric substrate 101, respectively. Such a piezoelectric substrate 101 vibrates at a frequency peculiar to the substrate when a predetermined voltage is applied between the electrodes 102 on both sides. That is, the portion sandwiched between the electrodes 102 of the piezoelectric substrate 101 functions as a piezoelectric vibrator. Thus, as shown in FIG. 2B, the electrodes 102 are arranged on both surfaces of the piezoelectric substrate 101, so that the vibrators 100f to 100h are arranged (arrayed). In this description, the vibrator array is formed by forming the counter electrodes on both surfaces of the piezoelectric substrate, but a structure in which a single vibration element is simply arranged on the insulating substrate according to the arrangement pattern may be used.

  The vibrators 100 (100a to 100c, 100e to 100j) formed in this way are wired with the wiring pattern shown in FIG. The first channel vibrators 100a aligned in the direction perpendicular to the bow-stern direction are connected in parallel by wiring patterns L12, L13, L14, and L15, respectively, and all the first channel vibrators 100a are connected to the port P1. Yes. Similarly, the second channel vibrator 100b is connected in parallel to the port P2 through wiring patterns L21, L22, L23, L24, and L25, and the third channel vibrator 100c is connected through wiring patterns L31, L32, L33, L34, and L35, respectively. The port P3 is connected in parallel. The fourth channel vibrator 100e is connected in parallel to the port P4 with wiring patterns L41, L42, L43, L44, and L45, respectively, and the fifth channel vibrator 100f is a port with wiring patterns L51, L52, L53, L54, and L55, respectively. The sixth channel vibrator 100g is connected in parallel to P5, and connected in parallel to the port P6 by wiring patterns L61, L62, L63, L64, and L65, respectively. Further, the seventh channel vibrator 100h is connected in parallel to the port P7 with wiring patterns L71, L72, L73, L74, and L75, respectively, and the eighth channel vibrator 100i is connected to the port P8 with wiring patterns L81, L82, L83, and L84, respectively. The ninth channel vibrator 100j is connected in parallel and connected in parallel to the port P9 by wiring patterns L91, L92, L93, and L94, respectively. These ports P1 to P9 are respectively connected to the respective lines of the bus line with the aforementioned transmission / reception switch 3, and the other terminals of the transducers 100a to 100c and 100e to 100j are, for example, each channel. Is grounded. With such a configuration, all the transducers of the planar transducer array 2 are divided and connected to the first channel to the ninth channel. The above-mentioned wiring pattern is realized by forming a wiring pattern electrode on one surface of the piezoelectric substrate in the case where the counter electrode is formed on both surfaces of the piezoelectric substrate, and when a single vibration element is used. This is realized by connecting the wiring pattern electrodes formed on the surface of the insulating substrate and the terminals of the vibration elements using conductor wires.

Next, the operation at the time of transmission of the detection device having such a configuration will be described.
(1) When driving transducers of nine channels substantially simultaneously in time division When a detection start command is input, the control circuit 6 generates an ultrasonic transmission signal corresponding to the input detection direction (tilt). The control signal is output to the transmission drive signal generation circuit 4 of the ultrasonic transducer 1. For example, in the case of the above-described transducer arrangement pattern (d = 10 mm), the tilt angle is π / 4 rad. (45 °), the frequency of the ultrasonic transmission signal is set to 70.7 kHz, and the tilt angle is π / 6 rad. If an input for (30 °) is input, the frequency of the ultrasonic transmission signal is set to 100 kHz. At this time, the control circuit 6 divides the nine channels into three groups, and also outputs a control signal for controlling the phase of the drive signal given to the group in a time division manner to the transmission drive signal generation circuit 4. Specifically, the control signals for the first channel to the third channel as the first group, the fourth channel to the sixth channel as the second group, and the seventh channel to the ninth channel as the third group are transmitted drive signals. Output to the generation circuit 4. By performing this control, as shown in FIG. 5, the planar transducer array 2 causes the first group transducer 110a, the second group transducer 110b, and the third group transducer 110c to be positive at a center distance 2d. This is equivalent to a structure arranged in a triangular lattice.
FIG. 5 is a configuration diagram showing the configuration patterns of the first to third groups of the planar transducer array 2.
In this structure, the arrangement position of the first group transducer 110a and the arrangement of the second group transducer 110b in the direction parallel to the bow-stern direction and the angle formed with respect to the bow-stern direction is π / 6. The position and the arrangement position of the third group transducer 110c are arranged at the interval d.

The transmission drive signal generation circuit 4 generates a transmission drive signal for the transducer to transmit an ultrasonic transmission signal having a desired frequency in accordance with the control signal input from the control circuit 6, and the phase of the transmission drive signal output for each group Take control. Specifically, the phase control shown in FIG. 6 (a), the phase control shown in FIG. 7 (a), and the phase control for setting all channels (groups) to the same phase are performed in a time division manner.
FIG. 6A is a block diagram showing the first phase control, and FIG. 6B shows the traveling direction of the transmission beam projected in the horizontal direction when the phase control shown in FIG. 6A is performed. FIG. FIG. 7A is a block diagram showing the second phase control, and FIG. 7B shows the direction of the transmission beam projected in the horizontal direction when the phase control shown in FIG. 7A is performed. FIG.
First, as shown in FIG. 6A, a reference transmission drive signal and 2π / 3 rad. A phase advance transmission drive signal; and 4π / 3 rad. The phase advance transmission drive signal is output to the transmission / reception switch 3 via the three bus lines. The reference transmission drive signal is output to the first to third channel vibrators (100a to 100c) constituting the first group vibrator 110a via the bus line and the ports P1 to P3, respectively, and 2π / 3 rad. The phase advance transmission drive signal is output to the fourth to sixth channel vibrators (100e to 100g) constituting the second group vibrator 110b via the bus line and the ports P4 to P6, respectively, and 4π / 3 rad. The phase advance transmission drive signal is output to the seventh to ninth channel vibrators (100h to 100j) constituting the third group vibrator 110c via the bus line and ports P7 to P9, respectively.

  When such a transmission drive signal is applied to each transducer, the ultrasonic signals transmitted from the first group transducer 110a, the second group transducer 110b, and the third group transducer 110c are shown in FIG. 2π / 3 rad. From the bow direction to the starboard direction. Rotated starboard rear and 2π / 3 rad. An equiphase surface perpendicular to the three directions behind the rotated port is provided in the direction of the tilt angle θ with respect to the horizontal direction. For this reason, three transmission beams TxBeam1 to TxBean3 having these directions as traveling directions are formed and transmitted in the detection area.

  Next, as shown in FIG. 7A, the reference transmission drive signal and 4π / 3 rad. A phase advance transmission drive signal and 2π / 3 rad. The phase advance transmission drive signal is output to the transmission / reception switch 3 via the three bus lines. Then, the reference transmission drive signal is output to the first to third channel vibrators (100a to 100c) constituting the first group vibrator 110a via the bus line and the ports P1 to P3, respectively, and 4π / 3 rad. The phase advance transmission drive signal is output to the fourth to sixth channel vibrators (100e to 100g) constituting the second group vibrator 110b via the bus line and the ports P4 to P6, respectively, and 2π / 3 rad. The phase advance transmission drive signal is output to the seventh to ninth channel vibrators (100h to 100j) constituting the third group vibrator 110c via the bus line and ports P7 to P9, respectively.

  When such a transmission drive signal is applied to each transducer, the ultrasonic signals transmitted from the first group transducer 110a, the second group transducer 110b, and the third group transducer 110c are shown in FIG. 2π / 3 rad. From the stern direction to the port side as shown in FIG. Rotated port forward and 2π / 3 rad. From stern direction to starboard direction. An equiphase surface perpendicular to the three directions in front of the rotated starboard is provided in the direction of the tilt angle θ with respect to the horizontal direction. For this reason, three transmission beams TxBeam4 to TxBeam6 having these directions as traveling directions are formed and transmitted in the detection area.

  Next, when a transmission drive signal having the same phase is applied to all the group transducers 110a to 110c, the equiphase plane becomes a direction perpendicular to the vertical direction, and a transmission beam TxBeam7 having the vertical direction as the traveling direction is formed. It is transmitted in the detection area.

FIG. 8 is a diagram showing the directivity of the transmission beam, where (a) shows the directivity in the horizontal direction, and (b) shows the directivity in the vertical direction.
By performing the above-described control, as shown in FIG. 8, a tilt angle θ is made with respect to the vertical direction from the planar vibrator array 2 installed on the bottom of the ship 200, and the bow direction, stern direction, bow To starboard direction from π / 3 rad. 2π / 3 rad. Rotated starboard front and starboard rearward, π / 3 rad. 2π / 3 rad. Transmit beams TxBeam 1 to 7 can be formed and transmitted in the detection area in substantially the same six directions of the forward port front and rear port and seven directions of the vertically downward direction.

Next, the simulation result of the transmission beam of the detection device having such a configuration will be described. In this simulation, the transducer interval d is set to 10 mm, the frequency of the ultrasonic signal is set to 100 kHz, and the sound speed is set to 1500 m / s.
FIG. 9A shows the horizontal directivity of the transmission beams TxBeam1 to 3, and FIG. 9B shows the vertical directivity of the transmission beam TxBeam1. Here, the horizontal directivity is 0 deg. With the cross section taken as an angle of π / 6 from the vertical direction. Indicates the bow direction,-direction indicates the port direction, and + direction indicates the starboard direction. The vertical directivity is 0 deg. With the cross section in the bow-stern direction. Is vertically downward, 90 deg. (Π / 2 rad.) Is the bow direction (horizontal plane), −90 deg. (−π / 2 rad.) Indicates the stern direction (horizontal plane).
As shown in FIG. 9, 0 deg. ± 120 deg. (± 2π / 3 rad.) Direction, that is, 120 deg. From the bow direction to the starboard direction from the bow direction. (2π / 3 rad.) Direction (starboard rear) and 120 deg. In the (2π / 3 rad.) Direction (back port side), the vertical directivity is 30 deg. (Π / 6 rad.) Direction, that is, an angle of 30 deg. Transmission beams TxBeam1 to 3 can be formed in a direction that generates (π / 6 rad.).

FIG. 10A shows the horizontal directivity of the transmission beams TxBeam4 to 6, and FIG. 10B shows the vertical directivity of the transmission beam TxBeam4. Here, the horizontal directivity is 30 deg. The direction that forms an angle of (π / 6 rad.) Is the cross section, and 0 deg. Indicates the bow direction,-direction indicates the port direction, and + direction indicates the starboard direction. The vertical directivity is 0 deg. With the cross section in the bow-stern direction. Is vertically downward, 90 deg. (Π / 2 rad.) Is the bow direction (horizontal plane), −90 deg. (−π / 2 rad.) Indicates the stern direction (horizontal plane).
As shown in FIG. 10, 180 deg. ± 120 deg. (± 2π / 3 rad.) Direction, that is, 120 deg. From the stern direction to the port side from the stern direction. (2π / 3 rad.) Direction (front port side) and 120 deg. In the (2π / 3 rad.) Direction (starboard front), the vertical directivity is 30 deg. (Π / 6 rad.) Direction, that is, an angle of 30 deg. Transmission beams TxBeam4 to 6 can be formed in a direction that generates (π / 6 rad.).

FIGS. 11A and 11B show the vertical directivity of the transmission beam TxBeam7. Here, the vertical directivity of FIG. 11 (a) has a cross section in the bow-stern direction, and 0 deg. Is vertically downward, 90 deg. (Π / 2 rad.) Is the bow direction (horizontal plane), −90 deg. (−π / 2 rad.) Indicates the stern direction (horizontal plane). Also, the vertical directivity of FIG. 11 (b) is 0 deg. Is vertically downward, 90 deg. (Π / 2 rad.) Is starboard direction (horizontal plane), −90 deg. (−π / 2 rad.) Indicates the port direction (horizontal plane).
As shown in FIG. 11, by performing the above-described control with the above-described configuration, the vertical directivity in the bow-stern direction and the vertical directivity in the starboard-portal direction are also 0 deg. The transmission beam TxBeam7 can be formed in the direction, that is, the direction directly below the vertical direction.

(2) When simultaneously driving the transducers of nine channels As in the case of (1) described above, when a detection start command is input, the control circuit 6 transmits the control signal to the ultrasonic transducer 1 for transmission. Output to the signal generation circuit 4. At this time, the control circuit 6 divides the nine channels into three groups and simultaneously outputs a control signal for controlling the phase of the drive signal applied to each group to the transmission drive signal generation circuit 4. Specifically, the first channel to the third channel, the fourth channel, and the seventh channel are set as the first group, the fifth channel and the ninth channel are set as the second group, and the sixth channel and the eighth channel are set as the third group. Is output to the transmission drive signal generation circuit 4.

  The transmission drive signal generation circuit 4 generates a transmission drive signal for the transducer to transmit an ultrasonic transmission signal having a desired frequency in accordance with the control signal input from the control circuit 6, and the phase of the transmission drive signal output for each group Take control. Specifically, the phase control shown in FIGS. 12 and 13 is performed. That is, the transmission drive signals output to the first channel to the third channel, the fourth channel, and the seventh channel belonging to the first group are used as reference signals, and 2π / 3 rad. A phase advance signal is output, and 4π / 3 rad. Outputs a phase advance signal.

FIG. 12 is a diagram showing the phase relationship of signals applied to each transducer of the planar transducer array, and FIG. 13 is a block diagram showing phase control.
Each transmission drive signal that is phase-controlled in this way is input to the transmission / reception switch 3 via a different bus line for each of the three groups. The transmission / reception switch 3 outputs three types of signals having different phases to the transducers of the respective channels according to the control signal. The transducer of each channel transmits an ultrasonic signal into the detection area in accordance with the applied transmission drive signal.

  14 and 15 are diagrams showing the relationship between each channel transducer and the transmission beam when the phase control shown in FIG. 13 is performed. FIG. 14A shows the second channel transducer and the fifth channel. FIG. 14B shows the relationship between the channel transducer, the eighth channel transducer, and the transmission beams TxBeam1 to TxBeam3, and FIG. 14B shows the third channel transducer, the sixth channel transducer, the ninth channel transducer, and the transmission beams TxBeam4 to TxBeam6. FIG. 15 shows the relationship between the first channel transducer, the fourth channel transducer, the seventh channel transducer, and the transmission beam TxBeam7. 14A, 14B, and 15A are views of the planar transducer array 2 viewed from the front, and FIG. 15B is a diagram of the planar transducer array 2 viewed from the side.

  (A) As shown in FIG. 14A, the row of the second channel transducer 100b, the row of the fifth channel transducer 100f, and the row of the eighth channel transducer 100i are in the bow-stern direction. 2π / 3 rad. From the bow direction to the starboard direction with respect to the bow-stern direction. 2π / 3 rad. From the bow direction to the port direction with respect to the direction of rotation and the bow-stern direction. There is a relationship of being arranged at a distance d parallel to the direction of rotation. 13 is performed, the drive signal applied to the fifth channel transducer 100f is 2π / 3 rad. With respect to the drive signal applied to the second channel transducer 100b. The drive signal applied to the eighth channel transducer 100i is 4π / 3 rad. The phase advances. As a result, as shown in FIG. 14A, the ultrasonic signals transmitted from the second channel transducer 100b, the fifth channel transducer 100f, and the eighth group transducer 100i are transmitted in the bow direction, starboard from the bow direction. 2π / 3 rad. Rotated starboard rear and 2π / 3 rad. An equiphase surface perpendicular to the three directions behind the rotated port is provided in the direction of the tilt angle θ with respect to the vertical direction. Therefore, three transmission beams TxBeam1 to TxBeam3 having these directions as traveling directions are formed and transmitted in the detection area.

  (B) Similarly, as shown in FIG. 14 (b), the row of the third channel vibrator 100c, the row of the sixth channel vibrator 100g, and the row of the ninth channel vibrator 100j are composed of the bow-stern. Direction, 2π / 3 rad. From the bow direction to the starboard direction with respect to the bow-stern direction. 2π / 3 rad. From the bow direction to the port direction with respect to the direction of rotation and the bow-stern direction. There is a relationship of being arranged at a distance d parallel to the direction of rotation. 13 is performed, the drive signal applied to the sixth channel transducer 100g is 4π / 3 rad. To the drive signal applied to the third channel transducer 100c. The drive signal applied to the ninth channel transducer 100j is 2π / 3 rad. The phase advances. As a result, as shown in FIG. 14 (b), the ultrasonic signals transmitted from the third channel transducer 100c, the sixth channel transducer 100g, and the ninth group transducer 100j are transmitted in the stern direction, and ported from the stern direction. 2π / 3 rad. Rotated port forward and 2π / 3 rad. From stern direction to starboard direction. An equiphase surface perpendicular to the three directions in front of the rotated starboard is provided in the direction of the tilt angle θ with respect to the vertical direction. For this reason, three transmission beams TxBeam4 to TxBeam6 having these directions as traveling directions are formed and transmitted in the detection area.

(C) Similarly, as shown in FIG. 15A, the row of the first channel vibrator 100a, the row of the fourth channel vibrator 100e, and the row of the seventh channel vibrator 100h are connected to the bow. -Stern direction, this bow-2π / 3 rad. From the bow direction to the starboard direction with respect to the stern direction. 2π / 3 rad. From the bow direction to the port direction with respect to the direction of rotation and the bow-stern direction. There is a relationship of being arranged at a distance d parallel to the direction of rotation. 13 is performed, the drive signals applied to the first channel transducer 100a, the fourth channel transducer 100g, and the ninth channel transducer 100j are in phase. As a result, as shown in FIG. 15, the equiphase surface of the ultrasonic signal is in the horizontal direction, and a transmission beam TxBeam 7 having the vertical downward direction as the traveling direction is formed and transmitted into the detection area.
Since the relationships (A), (B), and (C) occur simultaneously, the above-described transmission beams TxBeam 1 to 7 are also formed and output at the same time.

With such a configuration and control, as shown in FIG. 8, the tilt angle θ is made with respect to the vertical direction from the plane transducer array 2 installed on the bottom of the ship 200, and the bow direction, stern is determined. Direction, π / 3 rad. 2π / 3 rad. Rotated starboard front and starboard rearward, π / 3 rad. 2π / 3 rad. Transmission beams TxBeam 1 to 7 can be simultaneously formed and transmitted in the detection area in the rotated six directions of the port front and rear of the port and the seven directions of the vertical downward direction.
Next, the operation at the time of reception of the detection device having such a configuration will be described.
FIG. 16 is a block diagram showing phase control for forming a reception beam.
At the time of reception, the transmission / reception switch 3 outputs the reception signals received by the first to ninth channel transducers of the planar transducer array to the reception beam forming circuit 5 via individual bus lines. The reception beam forming circuit 5 has a circuit configuration that realizes the block diagram shown in FIG. 16, and includes nine reception signal synthesis circuits 51a to 51c and 51e to 51j that synthesize signals of three channel transducers in individual combinations. Among the output signals of these received signal combining circuits 51a to 51c and 51e to 51j, phase control circuits 52a to 52c, 52e to 52g, 53a to 53c, 53e to 53g for performing phase control of predetermined output signals, and received signals The output signals from the combining circuits 51a to 51c and 51e to 51j and the output signals from the phase control circuits 52a to 52c, 52e to 52g, 53a to 53c, and 53e to 53g are combined in different combinations. Reception signal combining circuits 54a to 54c and 54e to 51h that form reception beams are provided.
In the reception beam forming circuit 5 having such a configuration, reception beams RxBeam1 to RxBeam7 are formed from the reception signals received by the first to ninth channel transducers by the following method.

The reception signal synthesis circuit 51a synthesizes and outputs the reception signals output from the first, eighth, and ninth channel transducers, and the reception signal synthesis circuit 51b outputs from the second, third, and fourth channel transducers. The reception signal combining circuit 51c combines and outputs the reception signals output from the fifth, sixth, and seventh channel transducers. The output signals of these reception signal synthesis circuits 51a to 51c represent reception signals for each channel transducer group arranged in a direction perpendicular to the bow-stern direction.
The reception signal synthesis circuit 51e synthesizes and outputs the reception signals output from the second, seventh, and ninth channel transducers, and the reception signal synthesis circuit 51f includes the first, third, and fifth channel transducers. The received signal output is synthesized and output, and the received signal synthesis circuit 51g synthesizes and outputs the received signals output from the fourth, sixth, and eighth channel transducers. The output signals of these reception signal synthesis circuits 51e to 51g represent reception signals for each channel transducer group arranged in a direction perpendicular to the direction of 2π / 3 rotation from the bow direction to the starboard direction with respect to the bow-stern direction. .
The reception signal synthesis circuit 51h synthesizes and outputs the reception signals output from the third, seventh, and eighth channel transducers, and the reception signal synthesis circuit 51i includes the first, second, and sixth channel transducers. The received signal output is synthesized and output, and the received signal synthesis circuit 51j synthesizes and outputs the received signals output from the fourth, fifth and ninth channel transducers. The output signals of these reception signal combining circuits 51e to 51g are 2π / 3 rad. From the bow direction to the port direction with respect to the bow-stern direction. The received signal for each channel transducer group arranged in a direction perpendicular to the rotated direction is represented.

  The phase control circuits 52a to 52c and 52e to 52g perform phase control for advancing the phase of the output signals of the reception signal combining circuits 51c, 51e, 51i, 51a, 51f, and 51j by 2π / 3, respectively, and output the phase control circuits 53a to 53a. 53c, 53e to 53g perform phase control for advancing the phase of the output signals of the received signal synthesis circuits 51a, 51f, 51j, 51c, 51e, 51i by 4π / 3, respectively, and output the result.

The reception signal combining circuit 54a combines the output signal of the reception signal combining circuit 51b and the output signals of the phase control circuits 52a and 53a, and outputs a reception beam RxBeam1. FIG. 17A is a diagram in which this state is applied to each transducer of the planar transducer array, and a reception beam RxBeam1 is formed in the bow direction.
The reception signal synthesis circuit 54b synthesizes the output signal of the reception signal synthesis circuit 51g and the output signals of the phase control circuits 52b and 53b, and outputs a reception beam RxBeam2. FIG. 17B is a diagram in which this state is applied to each transducer of the planar transducer array, and 2π / 3 rad. A reception beam RxBeam2 is formed in the rotated direction.
The reception signal combining circuit 54c combines the output signal of the reception signal combining circuit 51h and the output signals of the phase control circuits 52c and 53c, and outputs a reception beam RxBeam3. FIG. 18A is a diagram in which this state is applied to each transducer of the planar transducer array, and 2π / 3 rad. A reception beam RxBeam3 is formed in the rotated direction.
The reception signal combining circuit 54e combines the output signal of the reception signal combining circuit 51b and the output signals of the phase control circuits 52e and 53e and outputs a reception beam RxBeam4. FIG. 18B is a diagram in which this state is applied to each transducer of the planar transducer array, and a reception beam RxBeam4 is formed in the stern direction.
The reception signal combining circuit 54f combines the output signal of the reception signal combining circuit 51g and the output signals of the phase control circuits 52f and 53f, and outputs a reception beam RxBeam5. FIG. 19 (a) is a diagram in which this state is applied to each transducer of the planar transducer array, and 2π / 3 rad. A reception beam RxBeam5 is formed in the rotated direction.
The reception signal synthesis circuit 54g synthesizes the output signal of the reception signal synthesis circuit 51h and the output signals of the phase control circuits 52g and 53g and outputs a reception beam RxBeam6. FIG. 19B is a diagram in which this state is applied to each transducer of the planar transducer array, and 2π / 3 rad. A reception beam RxBeam6 is formed in the rotated direction.
The reception signal combining circuit 54h combines the output signals of the reception signal combining circuits 51h, 51i, 51j and outputs a reception beam RxBeam7.

FIGS. 17, 18 and 19 are views showing the reception beams RxBeam 1 to 6 while applying the results of the phase control and the reception signal synthesis to each transducer arranged in the planar transducer array.
As shown in FIGS. 17, 18, and 19, the reception beam forming circuit 5 performs the above-described control to simultaneously form the reception beam RxBeam1 in the bow direction (FIG. 17A). 2π / 3 rad. A reception beam RxBeam2 is formed in the rotation direction (FIG. 17B), and 2π / 3 rad. A reception beam RxBeam3 is formed in the rotation direction (FIG. 18A), a reception beam RxBeam4 is formed in the stern direction (FIG. 18B), and 2π / 3 rad. The reception beam RxBeam5 can be formed in the rotation direction (FIG. 19A), and the reception beam RxBeam6 can be formed in the 2π / 3 rotation direction from the stern direction to the starboard (FIG. 19B). Although not shown, the reception beam RxBeam7 can be formed vertically downward by making the reception signals of all the channels in phase simultaneously with the reception beams RxBeam 1 to 6 described above.

Next, the reception beam simulation result of the detection apparatus having such a configuration will be described. In this simulation, the transducer array interval d is set to 10 mm, the frequency of the ultrasonic signal is set to 100 kHz, and the sound velocity is set to 1500 m / s.
FIG. 20A shows the horizontal directivity of the reception beam RxBeam1, and FIG. 20B shows the vertical directivity of the reception beam RxBeam1. Here, the horizontal directivity is 30 deg. The direction that forms an angle of (π / 6 rad.) Is the cross section, and 0 deg. Indicates the bow direction,-direction indicates the port direction, and + direction indicates the starboard direction. The vertical directivity is 0 deg. With the cross section in the bow-stern direction. Is vertically downward, 90 deg. (Π / 2 rad.) Is the bow direction (horizontal plane), −90 deg. (−π / 2 rad.) Indicates the stern direction (horizontal plane).
As shown in FIG. 20, by performing the above reception control with the above configuration, 0 deg. Direction, ie, in the bow direction, 30 deg. (Π / 6 rad.) Direction, that is, an angle of 30 deg. The reception beam RxBeam1 can be formed in a direction that generates (π / 6 rad.).

FIG. 21A shows the horizontal directivity of the reception beam RxBeam4, and FIG. 21B shows the vertical directivity of the reception beam RxBeam4. Here, the horizontal directivity is 30 deg. The direction that forms an angle of (π / 6 rad.) Is the cross section, and 0 deg. Indicates the bow direction,-direction indicates the port direction, and + direction indicates the starboard direction. The vertical directivity is 0 deg. With the cross section in the bow-stern direction. Is vertically downward, 90 deg. (Π / 2 rad.) Is the bow direction (horizontal plane), −90 deg. (−π / 2 rad.) Indicates the stern direction (horizontal plane).
As shown in FIG. 21, by performing the reception control with the above-described configuration, the horizontal directivity is 180 deg. (Π rad.) Direction, that is, stern direction, 30 deg. (Π / 6 rad.) Direction, that is, an angle of 30 deg. The reception beam RxBeam4 can be formed in a direction that generates (π / 6 rad.).

  For RxBeam2, RxBeam3, RxBeam5, and RxBeam6, the directivity similar to that of the above-described transmission beams TxBeam2, TxBeam3, TxBeam5, TxBeam6 is shown by comparing FIG. 9, FIG. 10, FIG. 20, and FIG. Therefore, the explanation and the illustration showing directivity are omitted. The reception beam RxBeam7 also exhibits directivity similar to that of the transmission beam TxBeam7, since it can be easily estimated by comparing FIG. 9, FIG. 10 with FIG. 20, FIG. 21, and referring to FIG. Illustrations showing directivity are omitted.

  By using the above configuration, an ultrasonic transducer that transmits an ultrasonic signal in seven directions and receives a reflected signal at the same time or substantially simultaneously is formed by a signal transmission circuit including nine channels for the transducer. Can be simplified and miniaturized. Further, by using this ultrasonic transducer, a detection device that can be easily controlled with a simple structure can be configured.

  In the above description, an example in which a transmission beam is formed with an ultrasonic signal having a predetermined set frequency has been described. However, this frequency may be changed according to the direction in which detection is performed.

FIG. 22 is a diagram showing the directivity of the transmission beams TxBeam1 to 3 when the frequency of the ultrasonic signal is set to 70.7 kHz, (a) shows the horizontal directivity of the transmission beams TxBeam1 to 3, and (b) Indicates the vertical directivity of the transmission beam TxBeam1. Here, the horizontal directivity is 45 deg. The direction that forms an angle of (π / 4 rad.) Is the cross section, and 0 deg. Indicates the bow direction,-direction indicates the port direction, and + direction indicates the starboard direction. The vertical directivity is 0 deg. With the cross section in the bow-stern direction. Is vertically downward, 90 deg. (Π / 2 rad.) Is the bow direction (horizontal plane), −90 deg. (−π / 2 rad.) Indicates the stern direction (horizontal plane).
As shown in FIG. 22, by performing this control with the above-described configuration, 0 deg. ± 120 deg. (± 2π / 3 rad.) Direction, that is, 120 deg. From the bow direction to the starboard direction from the bow direction. (2π / 3 rad.) Direction (starboard rear) and 120 deg. In the (2π / 3 rad.) Direction (backward port side), 45 deg. (Π / 4 rad.) Direction, that is, an angle of 45 deg. Transmission beams TxBeam1 to 3 can be formed in a direction that generates (π / 4 rad.).

FIG. 23 is a diagram showing the directivity of the reception beam RxBeam1 when the frequency of the ultrasonic signal is set to 70.7 kHz, (a) shows the horizontal directivity of the reception beam RxBeam1, and (b) The vertical directivity of the reception beam RxBeam1 is shown. Here, the horizontal directivity is 45 deg. The direction that forms an angle of (π / 4 rad.) Is the cross section, and 0 deg. Indicates the bow direction,-direction indicates the port direction, and + direction indicates the starboard direction. The vertical directivity is 0 deg. With the cross section in the bow-stern direction. Is vertically downward, 90 deg. (Π / 2 rad.) Is the bow direction (horizontal plane), −90 deg. (−π / 2 rad.) Indicates the stern direction (horizontal plane).
As shown in FIG. 23, by performing this reception control with the above-described configuration, the horizontal directivity is 0 deg direction, that is, the bow direction, and the vertical directivity is 45 deg. (Π / 4 rad.) Direction, that is, an angle of 45 deg. The reception beam RxBeam1 can be formed in a direction that generates (π / 4 rad.).

  Thus, by changing the frequency of the ultrasonic signal (frequency of the transmission drive signal), the angle with respect to the vertical downward direction can be changed in the same direction in the horizontal direction, and the desired underwater direction can be detected. It becomes possible.

  In the above description, the configuration in which ultrasonic signals having the same frequency are transmitted in all seven directions has been described. However, a transmission drive signal having a different frequency is applied for each beam direction, and ultrasonic signals having different frequencies are transmitted. Control may be performed. For example, the transmission drive signal for generating TxBeam7 transmitted in the vertically downward direction and the transmission drive signal for generating TxBeams 1 to 6 transmitted in the direction having the tilt angle θ in the vertical direction are set to different frequencies. May be. And by changing the frequency in this way, it is possible to suppress the influence of TxBeam7 on the reception beams RxBeam1 to 6 corresponding to TxBeam1 to 6 at the time of reception. That is, since the frequency of TxBeam7 is different from the frequency of TxBeam1-6, it is possible to prevent the seabed reflection of TxBeam7 from affecting RxBeam1-6. Thereby, detection can be performed more accurately.

  In the above description, the reception beams are formed simultaneously in the seven directions. However, the reception beams may be formed only in the three directions having an angle of 2π / 3. For example, according to the above-described example, only RxBeam1, RxBeam2, and RxBeam3 may be formed. With this configuration, the reception beam forming process is simplified and speeded up. Thereby, the detection direction is reduced as compared with the case of detecting the seven directions at the same time described above, but the detection can be performed at high speed in a direction that forms a predetermined angle with respect to the entire circumference. At this time, a configuration in which reception beams in seven directions are formed and only reception beams in three desired directions may be extracted, or a configuration in which only reception beams in three desired directions are formed in advance may be used. Good. By using a configuration that forms only reception beams in three directions in this way, the hardware configuration of the ultrasonic transducer can be simplified.

The block diagram which shows schematic structure of the detection apparatus provided with the ultrasonic transducer 1 of this invention. A plan view and a cross-sectional view showing the configuration of the planar transducer array 2 The figure which showed the positional relationship of each vibrator | oscillator of the plane vibrator | oscillator array 2 shown in FIG. The block diagram which showed the wiring pattern of the plane vibrator array 2 shown in FIG. The block diagram which shows the structure pattern of the 1st-3rd group of the plane vibrator array 2 The block diagram which shows 1st phase control, and the figure which shows the advancing direction of the transmission beam projected in the horizontal direction by this phase control The block diagram which shows 2nd phase control, and the figure which shows the advancing direction of the transmission beam projected in the horizontal direction in this phase control Diagram showing horizontal directivity and vertical directivity of transmission beam The figure which shows the horizontal directivity and vertical directivity of transmission beam TxBeam1-3. The figure which shows the horizontal directivity of transmission beam TxBeam4-6, and vertical directivity The figure which shows the vertical directivity of the transmission beam TxBeam7 The figure which showed the phase relation of the signal applied to each vibrator of a plane vibrator array Block diagram showing phase control The figure which shows the relationship between each channel vibrator | oscillator and transmission beam when the phase control shown in FIG. 13 is performed The figure which shows the relationship between each channel vibrator | oscillator and transmission beam when the phase control shown in FIG. 13 is performed Block diagram showing phase control to form receive beam The figure which shows receiving beam RxBeam1 and 2 while applying the result by phase control and receiving signal composition of receiving signal to each transducer arranged in a plane transducer array The figure which shows receiving beam RxBeam3 and 4 while applying the result by phase control of a receiving signal and a receiving signal composition to each vibrator arranged in a plane vibrator array The figure which shows receiving beam RxBeam5 and 6 while applying the result by phase control of a receiving signal and a receiving signal composition to each vibrator arranged in a plane vibrator array The figure which shows the horizontal directivity and vertical directivity of receiving beam RxBeam1 The figure which shows the horizontal directivity and vertical directivity of receiving beam RxBeam4 The figure which shows the horizontal directivity and vertical directivity of transmission beam TxBeam1-3 at the time of setting the frequency of an ultrasonic signal to 70.7 kHz. The figure which shows the horizontal directivity and vertical directivity of receiving beam RxBeam1 at the time of setting the frequency of an ultrasonic signal to 70.7 kHz A diagram showing the relationship between the phase of the drive signal applied to the transducers arranged in a specific direction and the transmission beam

Explanation of symbols

DESCRIPTION OF SYMBOLS 1- Ultrasonic wave transmitter / receiver 2-Plane transducer array 3-Transmission / reception wave switch 4-Transmission drive signal generation circuit 40-Transmission amplifier 5-Reception beam forming circuit 50-Reception amplifier 6-Control circuit 7-Image processing circuit 8 -Indicators 100, 101 to 104, 100a to 100c, 100e to 100j-Vibrators 110a to 100c-Vibrator groups 51a to 51c, 51e to 51j-Received signal synthesis circuits 52a to 52c, 52e to 52g, 53a to 53c, 53e to 53g—phase control circuits 54a to 54c, 54e to 51h—received signal synthesis circuits

Claims (8)

A plane transducer array comprising a 9-channel transducer array in which a plurality of transducers are arranged, and all transducers are arranged in an equilateral triangular lattice ,
In the transducer array, the distance between the centers of adjacent transducers is a length (2/3 ^1/2 ) d,
The first channel vibrator, the second channel vibrator, and the third channel vibrator are adjacent to each other in the shape of an equilateral triangle having a distance (2/3 ^1/2 ) d between the centers of the vibrators. The first group and the fourth channel vibrator, the fifth channel vibrator, and the sixth channel vibrator are positively set with the distance between the centers of each vibrator being a length (2/3 ^1/2 ) d. The second group formed adjacent to each other in a triangular shape, the seventh channel vibrator, the eighth channel vibrator, and the ninth channel vibrator are set to have a center-to-center distance of each vibrator (2/3 ^{1 / 2} ) A third group is formed adjacent to the equilateral triangular shape d.
The position and orientation of the second and third channel vibrators with respect to the first channel vibrator, the position and orientation of the fifth and sixth channel vibrators with respect to the fourth channel vibrator, The positions and orientations of the eighth and ninth channel vibrators with respect to the seven channel vibrators are in agreement with each other,
A plane transducer array in which the first group, the second group, and the third group are repeated in a pattern that is formed in a regular triangle shape with the distance between the centers of each group being 2d;
By applying a transmission drive signal having a predetermined phase relationship to the transducer of each channel of the planar transducer array, the transmission beam in a direction perpendicular to the transducer array surface of the planar transducer array, or the vertical 6 directions of transmission beams whose angle projected onto the transducer array surface radially with respect to the transmission beam in the direction is π / 3, or radially on the transducer array surface with respect to the transmission beam in the vertical direction An ultrasonic wave transmitter comprising: a transmission beam forming unit that forms a transmission beam in three directions with a projected angle of 2π / 3. It said transmit beamforming means for each group, phase 2π / 3rad. Ultrasonic wave transmitter according to claim 1, characterized in providing each provide different transmission driving signals, or the transmission driving signal of the same phase in all groups. A plane transducer array comprising a 9-channel transducer array in which a plurality of transducers are arranged, and all transducers are arranged in an equilateral triangular lattice,
In the transducer array, the distance between the centers of adjacent transducers is a length (2/3 ^1/2 ) d,
The first channel vibrator, the second channel vibrator, and the third channel vibrator are adjacent to each other in the shape of an equilateral triangle having a distance (2/3 ^1/2 ) d between the centers of the vibrators. The first group and the fourth channel vibrator, the fifth channel vibrator, and the sixth channel vibrator are positively set with the distance between the centers of each vibrator being a length (2/3 ^1/2 ) d. The second group formed adjacent to each other in a triangular shape, the seventh channel vibrator, the eighth channel vibrator, and the ninth channel vibrator are set to have a center-to-center distance of each vibrator (2/3 ^{1 / 2} ) A third group is formed adjacent to the equilateral triangular shape d.
The position and orientation of the second and third channel vibrators with respect to the first channel vibrator, the position and orientation of the fifth and sixth channel vibrators with respect to the fourth channel vibrator, The positions and orientations of the eighth and ninth channel vibrators with respect to the seven channel vibrators are in agreement with each other,
A plane transducer array in which the first group, the second group, and the third group are repeated in a pattern that is formed in a regular triangle shape with the distance between the centers of each group being 2d;
In-phase transmission drive signals are given to the first channel vibrator, the fourth channel vibrator, and the seventh channel vibrator,
Each of the second channel vibrator, the fifth channel vibrator, and the eighth channel vibrator is 2π / 3 rad. Give the drive signal for transmission whose phase advances
In each of the third channel vibrator, the ninth channel vibrator, and the sixth channel vibrator, 2π / 3 rad. By ultrasonic wave transmitter characterized in that the transmission beam forming means for providing a transmit drive signal phase is advanced, with a. An ultrasonic transmitter according to claim 2 or 3 ,
With respect to three groups adjacent to each other in a direction parallel to the first specific direction, which is composed of three channels arranged in a direction perpendicular to the first specific direction of the planar transducer array, the first specific direction The phase of the received signal of each group is 2π / 3 rad. A first phase control that is advanced step by step;
2π / 3 rad. In a predetermined rotation direction with respect to the first specific direction. For three groups adjacent to each other in a direction parallel to the second specific direction, which is composed of three channels arranged in a direction perpendicular to the second specific direction at an angle of In order, the phase of the received signal of each group is 2π / 3 rad. A second phase control that advances each time,
2π / 3 rad. For each of the first specific direction and the second specific direction. Along the third specific direction with respect to three groups adjacent to each other in a direction parallel to the third specific direction, which is composed of three channels arranged in a direction perpendicular to the third specific direction with an angle of In order, the phase of the received signal of each group is 2π / 3 rad. An ultrasonic wave transmitter / receiver comprising: a reception beam forming means for simultaneously performing third phase control for advancing one by one. An ultrasonic transmitter according to claim 2 or 3 ,
With respect to three groups adjacent to each other in a direction parallel to the first specific direction, which is composed of three channels arranged in a direction perpendicular to the first specific direction of the planar transducer array, the first specific direction The phase of the received signal of each group is 2π / 3 rad. First phase control for advancing step by step, and the phase of the received signal of each group in order along a fourth specific direction opposite to the first specific direction by 2π / 3 rad. 4th phase control to advance step by step,
2π / 3 rad. In a predetermined rotation direction with respect to the first specific direction. For three groups adjacent to each other in a direction parallel to the second specific direction, which is composed of three channels arranged in a direction perpendicular to the second specific direction at an angle of In order, the phase of the received signal of each group is 2π / 3 rad. Second phase control for advancing step by step, and the phase of the received signals of each group in order along a fifth specific direction opposite to the second specific direction by 2π / 3 rad. 5th phase control to advance step by step,
2π / 3 rad. For each of the first specific direction and the second specific direction. Along the third specific direction with respect to three groups adjacent to each other in a direction parallel to the third specific direction, which is composed of three channels arranged in a direction perpendicular to the third specific direction with an angle of In order, the phase of the received signal of each group is 2π / 3 rad. Third phase control for advancing each step, and the phase of the received signal of each group in order along the sixth specific direction opposite to the third specific direction is 2π / 3 rad. An ultrasonic transducer comprising: a reception beam forming means that simultaneously performs sixth phase control that is advanced step by step.   The ultrasonic transducer according to claim 4 or 5, wherein the reception beam forming means includes in-phase control for setting the reception signals of all channels to the same phase, and also performs the in-phase control at the same time.   The reception beam forming means includes a first reception control for simultaneously performing the first phase control, the second phase control, and the third phase control, the fourth phase control, and the fifth phase control. And a second reception control that simultaneously performs the sixth phase control, and at least one of the first reception control and the second reception control is executed. Waver. The ultrasonic transducer according to any one of claims 4 to 7, comprising:
A detection apparatus comprising: detection data generation means for controlling the transmission drive signal and generating detection data based on a reception beam made up of the reception signal.

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