JP2009031082A - Ultrasonic apparatus for detecting edge position - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ultrasonic apparatus for detecting edge position, capable of easily enlarging the acoustic separation between adjacent elements and having a high degree of freedom in the number and arrangement of elements. <P>SOLUTION: The ultrasonic apparatus for detecting edge position is provided with: an oscillation part 1 for oscillating ultrasonic waves; a reception part 2 for receiving ultrasonic waves oscillated from the oscillation part 1; and a detection processing part 3 for processing the detection of the edge positions of an object 10 to be detected inserted between the oscillation part 1 and the reception part 2 on the basis of results of reception by the reception part 2. The oscillation part 1 is provided with a plurality of oscillation elements 6 for oscillating ultrasonic waves, and each oscillation element 6 is provided with a matching layer 12 and a core 13 joined to the matching layer 12. The matching layers 12 of the oscillation elements 6 are separated from one another. The reception part 2 is provided with a plurality of reception elements 7 for receiving ultrasonic waves, and each reception element 7 is provided with a matching layer 12 and a core 13 joined to the matching layer 12. The matching layers 12 of the reception elements 7 are separated from one another. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

  The present invention relates to an ultrasonic edge position detection device.

  As an apparatus for detecting an edge position (end position) of an object to be detected, an ultrasonic edge position detection apparatus is known.

  As a prior art document disclosing an ultrasonic edge position detection device, for example, there is Patent Document 1.

  FIG. 11 is a perspective view showing the configuration of the oscillating unit and the receiving unit of the ultrasonic edge position detecting device of Patent Document 1. In FIG.

As shown in FIG. 11, the oscillating unit and the receiving unit of the ultrasonic edge position detection device of Patent Document 1 are configured by arranging the cores 1002 in a staggered manner using the matching layer 1001 as a common base.
US Pat. No. 5,834,877

  In the ultrasonic edge position detection device of Patent Document 1, since the matching layer 1001 is common to each core 1002, there is a problem that it is difficult to achieve acoustic separation between adjacent elements, There was a problem that the number and arrangement were restricted.

  The present invention has been made to solve the above-described problems, and it is easy to enhance acoustic separation between adjacent elements, and an ultrasonic type having a high number of elements and a high degree of freedom in arrangement. An object is to provide an edge position detection device.

  In order to solve the above problems, an ultrasonic edge position detection device according to the present invention includes an oscillating unit that oscillates ultrasonic waves, a receiving unit that receives ultrasonic waves oscillated from the oscillating unit, the oscillating unit, and the receiving unit. In the ultrasonic type edge position detection device comprising: a detection processing unit that performs a process of detecting an edge position of an object to be detected inserted between the detection unit and the detection unit based on a reception signal from the reception unit. Includes a plurality of oscillating elements that oscillate ultrasonic waves, and each oscillating element includes a matching layer and a core bonded to the matching layer, and the matching layers of the oscillating elements are separated from each other, and the receiving unit Includes a plurality of receiving elements for receiving ultrasonic waves, each receiving element includes a matching layer and a core bonded to the matching layer, and the matching layers of the receiving elements are separated from each other. It is characterized by.

  According to the present invention, since the matching layer is separated for each oscillation element and for each reception element, it is easy to enhance acoustic separation between adjacent elements, and It is possible to increase the number and the degree of freedom of arrangement.

  Embodiments according to the present invention will be described below with reference to the drawings.

  FIG. 1 is a front view showing a configuration of an ultrasonic edge position detection apparatus 100 according to the embodiment.

  The ultrasonic edge position detection apparatus 100 according to the present embodiment detects the position of the end (edge) of the detection object 10, and as shown in FIG. It consists of a lower part 100B located on the lower side and an intermediate part 100C that connects these parts 100A and 100B to each other, and has an overall U-shaped cross section.

  A space between the upper portion 100A and the lower portion 100B constitutes an insertion region 100D into which the detection object 10 is inserted.

  For example, the lower part 100B is provided with an oscillating unit 1 that oscillates ultrasonic waves, and the upper part 100A includes a receiving unit 2 that receives ultrasonic waves oscillated from the oscillating unit 1 and a CPU. And a detection processing unit 3 that performs detection processing of the edge position of the detected object based on the reception result of 2.

  Although FIG. 1 shows an example in which the oscillation unit 1 is on the lower side and the reception unit 2 is on the upper side, the oscillation unit 1 may be on the upper side and the reception unit 2 may be on the lower side.

  FIG. 2 is a plan view showing the element mounting base 4 provided in each of the oscillation unit 1 and the reception unit 2.

  As shown in FIG. 2, the element mounting base 4 includes a plurality of pockets 5 in which elements (oscillation elements, receiving elements) are mounted.

  As shown in FIG. 1, an oscillation element 6 that oscillates an ultrasonic wave is attached to each pocket 5 of the element mounting base 4 of the oscillation unit 1.

  Similarly, a receiving element 7 that receives ultrasonic waves oscillated from the oscillating element 6 is attached to each pocket 5 of the element mounting base 4 of the receiving unit 2.

  The oscillation unit 1 and the reception unit 2 are arranged so that the oscillation element 6 of the oscillation unit 1 and the reception element 7 of the reception unit 2 face each other.

  Here, the pockets 5 of the element mounting base 4 of the oscillating unit 1 are arranged so that the oscillating elements 6 are arranged in a staggered manner and the interval between the oscillating elements 6 is as narrow as possible.

  Similarly, the pockets 5 of the element mounting base 4 of the receiving unit 2 are arranged so that the receiving elements 7 are arranged in a staggered manner and the interval between the receiving elements 7 is as narrow as possible.

  As described above, the reason why the oscillation elements 6 and the reception elements 7 are arranged in a staggered manner with a short interval between the elements is to connect the visual fields that the elements 6 and 7 can individually detect without interruption. (Electrically, the detection signals (reception signals) of the respective receiving elements 7 are overlapped with each other and are calculated as detection signals in the entire visual field).

  FIG. 3 is a perspective view showing the oscillation element 6 and the reception element 7.

  As shown in FIG. 3, the oscillation element 6 and the reception element 7 have a round cylindrical case 11, and a matching layer 12 is used in a portion in contact with air in the oscillation or reception unit. The

  A core 13 is disposed inside the case 11, and the core 13 is bonded to the matching layer 12.

  The core 13 is an element that mutually converts electrical energy and mechanical kinetic energy. A ceramic piezoelectric element is known as the core 13.

  A pair of leads 14 is led out from the lower surface of the case 11.

  Here, examples of the element include a self-fixing type and a non-fixing type, and further, there are a round type and a square type for each of the self-fixing type and the non-fixing type.

  FIG. 3 shows a non-fixed round shape.

  FIG. 4 shows self-fixing and round elements 6 and 7.

  The elements 6 and 7 shown in FIG. 4 include a round core 15 and a rectangular matching layer 16 wider than the core 15, and the matching layer 16 is connected to the element mounting base 4 by screws or the like. It can be fixed using a fastening member.

  FIG. 5 shows non-fixed and square elements 6 and 7.

  The elements 6 and 7 shown in FIG. 5 include a square core 17 and a square matching layer 18 having a shape and dimensions that overlap the core 17.

  FIG. 6 shows self-fixing and square elements 6 and 7.

  The elements 6 and 7 shown in FIG. 6 include a square core 17 and a square matching layer 19 wider than the core 17, and the matching layer 19 is connected to the element mounting base 4 with screws or the like. It can be fixed using a fastening member.

  In any of the elements 6 and 7 shown in FIGS. 3 to 6, unlike the conventional element (FIG. 11), each element includes a core and a matching layer. That is, the matching layer is separated for each element. And each element 6 and 7 is arrange | positioned at the element mounting base 4 with high sound-insulation property.

  The advantage of separating the core together with the matching layer in this way is that it is easy to enhance acoustic separation from the adjacent elements, and is effective in oscillating and receiving a plurality of elements. Furthermore, since the number and arrangement of elements are free, they can be used in common for various applications.

  Further, among the elements shown in FIGS. 3 to 6, the element having the square core 17 as shown in FIGS. 5 and 6 has a visual field characteristic per element suitable for edge detection as described below. In addition to the advantages, it has the advantage of easy arrangement of elements.

  FIG. 7 is a diagram showing the relationship between the edge position (insertion amount) of the detected object and the detection amount when an element having a square core 17 is used, and FIG. 8 is a case where an element having a round core is used. It is a figure which shows the relationship between the edge position (insertion amount) of a to-be-detected object, and detection amount.

  The relationship between the edge position of the object to be detected and the detection amount is greatly related to how the received ultrasonic wave changes. As shown in FIG. 8, the graph showing the relationship cannot be a straight line when the core is round, and shows an S-shaped change characteristic.

  On the other hand, when the core is rectangular, as shown in FIG. 7, the straight line portion in the graph showing the relationship between the edge position of the detected object and the detected amount is large. In the round shape and the square shape, the relationship between the detected object edge position and the detection area is more straight in the square shape.

  When a square element is used, both the oscillation element 6 and the reception element 7 may be square elements, or only one of the oscillation element 6 and the reception element 7 may be a square element. .

  FIG. 9 is a diagram showing an example of the arrangement of elements.

  As shown in FIG. 9, when a plurality of elements are arranged in the horizontal direction (in this case, two rows), the rectangular shape is easier to close the intervals between the elements. Therefore, when the detection signal of each element is handled, since the straight portion is long, it is easy to improve the linearity in the entire visual field region.

  As shown in FIG. 9, when 10 elements are arranged on the oscillation side and the reception side, the element No. When the edge of the object to be detected is at position 6, the edge position is detected within the field of view of the element.

  Here, since an element that handles ultrasonic waves is generally easily affected by changes in the surrounding environment, an element (No. 1) that does not always detect an edge is provided to serve as a reference for all elements (for reference). Let me detect it.

  Further, the elements on both sides (No. 5, No. 7) of the element (No. 6) that detects the edge are also detected at the same time.

  The above element No. 1, 5, and 7 are used for correction.

  Element No. 1 and No. 7, the detection amounts 0% and 100% of the detection object are always measured, and are used as the scale reference of the detection signal.

  Regarding the function of the element (No. 7) having a detection amount of 100%, when an object to be detected that easily transmits ultrasonic waves, such as an ultra-thin film or a non-woven fabric, is used, the element No. The detected amount of 7 is not 100%.

  By constantly updating the scaling from fully closed (for example, No. 7) to fully open (No. 1) by comparison with the detection value of the element (No. 1) having a detection amount of 0%, the edge detection element ( The detection value of No. 6) can be measured as a correct edge position.

  Each element varies in performance individually, but removes the object to be detected, measures the value when all elements are fully opened (detection amount 0%), and detects the value detected with the reference element (No. 1). By storing the ratio in a memory or the like and correcting the measured values of the edge detection element (No. 6) and the reference element (No. 1) using the stored values during actual operation, Each variation is eliminated.

  In this way, the detection processing unit 3 uses the detection value (received signal) by the receiving element (No. 6) that detects the edge position of the detected object 10 as the receiving element (No. .1) and the detection value by the receiving element (No. 7) having a detection rate of the detection object of 100% are corrected.

  As another purpose of keeping the elements (No. 5, No. 7) on both sides of the edge detection element (No. 6) in the measurement state, the validity of the edge detection element (No. 6) is confirmed. Sometimes. That is, the detection values of the adjacent elements (No. 5 and No. 7) are always measured and used for condition determination when the edge detection element is moved. In addition, by activating both adjacent elements, accurate measurement can be performed immediately after the movement of the edge detection element.

  Next, a method for driving the oscillation element and a method for processing the received signal will be described.

  FIG. 10 is a diagram for explaining the detection operation, and shows the temporal change of the oscillation / drive signal from the oscillation element 6 and the reception signal by the reception element 7.

  As the ultrasonic frequency, 40 KHz to 400 KHz is generally used.

  A rectangular wave is generally used as the waveform, but high-energy harmonics are likely to be generated when the polarity is switched, and the efficiency of converting to ultrasonic energy is poor.

  For this reason, in this embodiment, a triangular wave is used. A sine wave (sin wave) is ideal, but when it is achieved by hardware or software, it is difficult to be simple. Triangular waves can be realized with simple hardware, and the generated ultrasonic waves are similar to those of sine waves and have little loss.

  A burst mode is used as the ultrasonic wave generation form.

  The received signal is subjected to detection and LPF (low pass filter) processing, and the rising slope of the signal is measured and evaluated as shown in FIG. A method for measuring and evaluating the rising slope of the signal in this way is detailed in Japanese Patent Application Laid-Open No. 2003-97933 by the present applicant.

  When the detection amount is 100% (fully closed state), the slope of the rising edge of the signal is zero.

  According to the embodiment as described above, the end (edge) position of the object to be detected can be detected within a wide field of view.

  Moreover, since the matching layer is separated for each oscillation element and for each reception element, it is easy to increase acoustic separation between adjacent elements, and the number and arrangement of elements. It is possible to increase the degree of freedom.

  In the above embodiment, the example in which the elements on the oscillation side and the reception side are separated has been described. However, the oscillation and reception may be used in some cases.

It is a front view which shows the structure of the ultrasonic type edge position detection apparatus which concerns on embodiment. It is a top view which shows the element attachment base. It is a perspective view which shows an example of an element. It is a perspective view which shows an example of an element. It is a perspective view which shows an example of an element. It is a perspective view which shows an example of an element. It is a figure which shows the relationship between the edge position (insertion amount) of a to-be-detected object and detection amount at the time of using the element which has a square-shaped core. It is a figure which shows the relationship between the edge position (insertion amount) of a to-be-detected object at the time of using the element which has a round core, and detection amount. It is a figure which shows an example of the arrangement | sequence of an element. It is a figure for demonstrating a detection operation. It is a perspective view which shows the conventional element.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Ultrasonic edge position detection apparatus 1 Oscillation part 2 Reception part 3 Detection processing part 6 Oscillation element 7 Reception element 12 Matching layer 13 Core 15 Core 16 Matching layer 17 Core 18 Matching layer 19 Matching layer

Claims (3)

An oscillator that oscillates ultrasonic waves;
A receiver for receiving ultrasonic waves oscillated from the oscillator;
A detection processing unit that performs processing for detecting an edge position of an object to be detected inserted between the oscillating unit and the receiving unit based on a received signal by the receiving unit;
In an ultrasonic edge position detection device comprising:
The oscillation unit includes a plurality of oscillation elements that oscillate ultrasonic waves,
Each oscillation element includes a matching layer and a core bonded to the matching layer,
The matching layers of each oscillation element are separated from each other,
The receiving unit includes a plurality of receiving elements for receiving ultrasonic waves,
Each receiving element includes a matching layer and a core bonded to the matching layer,
An ultrasonic edge position detecting device, wherein matching layers of each receiving element are separated from each other.   The detection processing unit receives a reception signal from a receiving element that detects an edge position of the detection object, a reception signal from a reception element having a detection rate of 0%, and a detection rate of the detection object of 100%. The ultrasonic edge position detection apparatus according to claim 1, wherein correction is performed based on a reception signal from the element.   3. The ultrasonic edge position detection device according to claim 1, wherein at least one of the oscillation element and the reception element has a square shape. 4.

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