JPH0465617A - Method and instrument for measuring seam packer ring utilizing ultrasonic wave - Google Patents

Abstract

PURPOSE:To excellently measure the seam packer ring by converging an ultrasonic wave beam, irradiating the surface of a ground with the beam, receiving and converting its reflected wave into an electric signal, and displaying a light- shade image. CONSTITUTION:While moving an aerial ultrasonic sensor relatively along the ground surface, the sensor receives and converts the reflected wave into the electric signal, which is sent to a receiver and further sent to an image processor, so that processing for image generation is performed. Namely, this image processor converts the input signal into a binary signal first by an A/D converter. The binary-coded signal shows reflection intensity at each point and is sent to a computer, which converts this reflection intensity into a light-shade signal and displays the image on its screen or records it in a secondary storage device. Namely, the measurement result obtained by moving the sensor relatively along the ground surface is outputted as the image and then the seam packer ring can be displayed in the form of clear gradation variation.

Description

[Detailed Description of the Invention] [Industrial Field of Application] Seam puckering is an important element in the quality of manufactured products in the sewing process. Seam puckering is a wrinkle that occurs near the seam opening when fabric is sewn.

The present invention relates to a measuring method and apparatus for measuring seam puckering using ultrasonic waves.

[Prior Art] Seam puckering has conventionally been evaluated by human comparison with samples. As a quantitative method, attempts have been made to fix the fabric with resin and cut it and measure the cross-sectional shape, or to measure the surface shape using moiré fringes.

However, the cross-sectional measurement method is a destructive test, and the method using moiré is non-destructive, but has a limited accuracy.

On the other hand, methods have also been devised to accurately measure surface shapes without contact. This method irradiates the fabric surface with laser light, detects the position where the scattered light image forms on a semiconductor optical sensor, and uses a displacement meter that measures the position of the point reflecting the laser light using the principle of triangulation. I am using it. This displacement meter is fixed, the fabric is moved using a moving device in a plane perpendicular to the laser beam from the displacement meter, and the shape of the fabric surface is determined by measuring the digits of many points on the fabric surface. Seam puckering is evaluated based on the measured surface shape of the fabric.

However, with such a measurement method, it is difficult to measure extremely minute surface displacements.

For example, in women's clothing, seam puckering is a problem that is so minute that it can barely be seen with the naked eye, but conventional devices cannot clearly detect this problem.

[Problems to be Solved by the Invention] The object (7) of the present invention is to obtain a method and apparatus that can easily measure such minute displacements of cloth with high sensitivity.

[Means for Solving the Problems] In order to solve the above problems, the present invention uses ultrasonic waves to measure seam puckering. While moving the fabric relatively, the ultrasonic beam is focused and irradiated onto the surface of the fabric, and the reflected waves are received and converted into electrical signals.
By processing the electric signal in an image processing device, the reflected wave intensity is converted into shading and displayed as an image.

In addition, the seam puckering measurement device of the present invention includes an airborne ultrasonic sensor that converges and irradiates an ultrasonic beam onto the fabric surface and converts the reflected wave into an electrical signal, and a image processing in which the intensity of the reflected wave is converted into a signal to be displayed as an image by converting the intensity of the reflected wave into shading by processing the signal received by the moving device that relatively moves in parallel along the plane and the above-mentioned aerial ultrasonic sensor; It consists of a device.

[Function] Airborne ultrasonic sensors have strong directivity, and the reflected strength strongly depends on the incident angle of the ultrasonic beam, and has extremely high sensitivity to angle. Therefore, even if the displacement of the measurement surface is minute, if there is an inclination, it can be detected as a change in the reflected wave intensity.

That is, the received anti! Since the intensity of the l'f wave reflects the inclination due to the unevenness of the fabric surface, the sensor is relatively moved along the fabric surface using a two-axis moving device, and measurements are taken at many points on the fabric surface. By imaging it, seam puckering can be measured as a clear shade change.

[Examples] The present invention will be explained in more detail through specific examples.
The seam puckering method ffl+ according to the present invention utilizes an airborne ultrasonic sensor.

This aerial ultrasonic sensor has a concave beam projection surface that forms a converging lens for the ultrasonic beam. In total i++, this aerial ultrasonic sensor is activated by an oscillator, and an ultrasonic beam is focused and irradiated perpendicularly to the surface of the fabric.

The ultrasonic beam emitted from the sensor has a certain diameter, and the measured reflected wave intensity is the total amount of reflection from the surface where the beam hits the fabric. Therefore, the smaller the diameter of the anti-slanted surface of the ultrasonic beam on the fabric surface, the narrower the measurement range, and the better the resolution when the focal length of the sensor is the distance between the sensor and the fabric. Become the highest.

In the measurement, the sensor is moved in parallel along a plane parallel to the fabric surface using a two-axis moving device, and reflected waves are measured at a large number of points on the fabric surface. It is also possible to move the fabric relative to the sensor.

While moving the aerial ultrasonic sensor relatively along the fabric surface, the sensor receives reflected waves and converts them into electrical signals, which are sent to a receiver and then to an image processing device to create an image. processing is performed. That is, in this image processing device, first, the input signal is A/
It is binarized by a D converter. The binarized signal represents the reflection intensity at each point and is sent to a computer, which converts this reflection intensity into a gray signal and displays it on the computer screen or records it in a secondary storage device as an image. .

Airborne ultrasonic sensors have strong directivity, and the intensity of one reflection strongly depends on the incident angle of the ultrasonic beam. For example, compared to the case where the ultrasonic beam is incident perpendicularly to the fabric, when the incident angle is tilted by about 5 degrees, the intensity may be about 1730, and the sensitivity to angle is very high. Therefore, even if the displacement of the measurement surface is minute, if there is a tilt in the fabric, it can be detected as a change in the reflected wave intensity.

In other words, since the intensity of the received reflected wave reflects the inclination due to the unevenness of the fabric surface, seam puckering can be detected by moving the sensor relatively along the fabric surface and converting the measurement results into an image. It can be displayed as a clear shade change.

For actual measurement, the frequency is 910kHz and the focal length! ! 60
An ultrasonic flaw detection device was used as the measurement system using a mm airborne ultrasonic sensor. This device is composed of an ultrasonic transmitter, a receiver, a 3-axis scanner, and an image processing device, and is a device that measures the ultrasonic reflection intensity in a specified range and converts it into an image.

Since the sample measured was created with women's clothing in mind, the degree of wrinkles is very mild compared to various samples. As a result of measurement using such a sample, we were able to obtain a measurement image using aerial ultrasound that clearly showed the shadows of wrinkles on both sides of the fabric seam line, but measurements using laser distance measurement In the comparative example image,
It was not possible to clearly capture the unevenness of the wrinkles.

In particular, in ultrasound images, the brightness represents the reflection intensity;
An image obtained by laser distance measurement shows the distance between the sensor and the measurement point on the sample. Due to this difference, seam puckering is displayed as a clear shade change in ultrasound images.

In order to clarify the directivity of the aerial ultrasonic sensor, the distance between the sensor and the measurement point is kept constant, and the angle between the central axis of the sensor and the normal to the measurement surface is changed in 1 degree increments to measure the reflection intensity. was measured. The results are shown in Figure 2. The vertical axis is the ratio of reflection intensity, and the horizontal axis is the angle formed between the axis of the aerial ultrasonic sensor and the reflecting surface.

In the figure, since the reflection intensity is rapidly attenuated within a range of about 5 degrees, it can be seen that the sensitivity to the inclination angle of the measurement surface is high. In laser distance measurement, the surface shape of the measurement target is measured, but in measurement using ultrasonic waves, information on the inclination angle of the measurement surface is indirectly obtained. Therefore, in the case of ultrasonic waves, the sensitivity to minute displacements is higher than that of laser distance measurement, and it is effective in evaluating cases where very mild seam puckering is a problem.

[Effects of the Invention] Since the present invention is configured as described above,
It is possible to easily detect seam puckering with high sensitivity, even when it is extremely minute and barely visible to the eye, such as on women's clothing, which would have been unthinkable using laser light.

[Brief explanation of the drawing]

The drawings show embodiments of the present invention, and FIG. 1 is a block diagram of the apparatus. FIG. 2 is a graph showing an example of the characteristic of an airborne ultrasonic sensor. designated agent

Claims (1)

[Claims] 1. While moving the aerial ultrasonic sensor relatively along the fabric surface, it irradiates the fabric surface with a focused ultrasonic beam, and receives the reflected waves and converts them into electrical signals. ,
A method for measuring seam puckering using ultrasonic waves, characterized in that the electric signal is processed in an image processing device to convert the reflected wave intensity into gradation and display as an image. 2. An aerial ultrasonic sensor that converges and irradiates an ultrasonic beam onto the fabric surface and converts the reflected waves into electrical signals, and movement that moves the aerial ultrasonic sensor relatively parallel to the fabric surface. A seam packer using ultrasonic waves, comprising: a device; and an image processing device that processes signals received by the aerial ultrasonic sensor to convert the intensity of reflected waves into shading signals to be displayed as an image. Ring measuring device.