CN201034557Y - Cylinder inside and outside wall machine precision on-line image-forming testing apparatus - Google Patents
Cylinder inside and outside wall machine precision on-line image-forming testing apparatus Download PDFInfo
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- CN201034557Y CN201034557Y CNU200620168791XU CN200620168791U CN201034557Y CN 201034557 Y CN201034557 Y CN 201034557Y CN U200620168791X U CNU200620168791X U CN U200620168791XU CN 200620168791 U CN200620168791 U CN 200620168791U CN 201034557 Y CN201034557 Y CN 201034557Y
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Abstract
The utility model belongs to an online detection system based vision, in particular to an online imaging detection device for detecting the machining accuracy of the inner wall and outer wall of cylinder. The device includes a shell (1), a laser (2), a reflector (3), a light way conversion mirror (4) and a part for receiving and processing images. After the laser generated by the laser (2) is reflected by the reflector (3), the laser is cast on the detecting the inner surface of the cylinder. The diffuse reflection light spot is caught by the light way conversion mirror (4), which is assembled to the receiving and processing images part for processing. The part for receiving and processing images (5) includes an image acquisition and processing module, a digital signal processing module, a data preservation module and a data transferring and displaying module. The image of diffuse reflection light spot is collected and processed by the image collecting and processing module. The data from the image collecting and processing module is received by the data single processing module, after operation processing, the relative results are stored in the data preservation module.
Description
Technical Field
The utility model belongs to an online detecting system field based on vision especially relates to an online formation of image detection device of drum inside and outside wall machining precision.
Background
The precursor process of the cylinder product is high-temperature steel stamping forming. Due to vibration and abrasion, the stamping device can have large deviation after working for a period of time. For the above-mentioned deviation, the conventional solution is: and punching a batch of cylinders, performing sampling inspection after cooling, scrapping the batch if the cylinders are unqualified, and correcting the punching equipment so as to continue production. The traditional method has great waste and greatly limits the working speed of the production line.
Based on the complexity of the appearance factor of the object to be measured, the algorithm design also has certain complexity. The cylinder to be measured has small mouth, large abdomen and bottom, and the surface of the inner wall of the cylinder cannot be directly projected or remotely measured from the outside, and a detection device extending into the cylinder is required to detect the inner wall. The measurement of the object to be measured generally comprises two parts of inner wall point position measurement and inner and outer wall position fitting. The inner wall surface is not smooth, the field condition is complex, the image noise is large, and the algorithm needs to be accurately designed by combining experiments. And fitting the data of the surfaces of the inner wall and the outer wall, namely fitting the planes of the inner wall and the outer wall from the position data of the points of the inner wall and the outer wall, and calculating the uniformity of the inner wall and the outer wall.
The following candidates exist for the interior wall point position detection:
1) Probe type contact measurement
The probe is adopted to contact the surface of an object to be detected, and the surface uniformity of the object is determined according to the displacement of the probe, and the probe has the following defects:
1. the probe contacts the surface of the object to be measured, and the surface of the object to be measured in the system has high temperature and high hardness, and the probe is easy to wear.
2. The probe is of a mechanical structure, a mechanical transmission device is required to carry out accurate displacement when the probe moves, the scanning speed is low, and the requirement of flow detection on a production line cannot be met.
2) Infrared ray measurement
The infrared light source is used for irradiating the surface of the object, and the uniformity of the surface of the object is determined according to the reflected infrared rays, which has the following disadvantages:
1. the cylinder to be measured is small in mouth and big in belly, and infrared rays are not easy to scan the whole surface.
2. The cylinder is made of high-temperature steel, and the surface of the cylinder is covered with a black oxide layer, so that the surface of the cylinder is a slightly rough black surface. Such surfaces are highly absorptive of infrared light and it is difficult to obtain effective reflective properties.
3) Ultrasonic measurement
The uniformity of the object to be measured is determined by conducting and reflecting ultrasonic waves in the object and measuring the time of the whole process of sending and recovering the ultrasonic waves, and the defects are as follows:
1. the ultrasonic wave generating device needs to be contacted with the surface of an object to be measured, the high temperature on the surface of the cylinder is easy to generate corrosive wear on the ultrasonic wave generating device, and the oxide layer on the surface of the cylinder makes the ultrasonic wave generating device not tightly contacted.
2. The high temperature of the cylinder greatly affects the propagation speed of the ultrasonic wave, which is essentially a vibration wave, and the accuracy of the measurement is also affected.
4) Laser measurement
Irradiate a beam of laser on the surface of an object, measure the intensity of the reflected laser or the change of the position of a light spot, detect the uniformity of the inner wall, and have the following defects:
1. the cylinder to be measured has a small mouth and a large belly, and the laser cannot easily scan the whole surface.
2. The calculation is relatively complex.
5) And (6) visually measuring.
The method comprises the following steps of irradiating an object to be detected by adopting a light source, carrying out three-dimensional fitting after collecting images by using an image sensor, and calculating the uniformity of an inner wall, wherein the method has the following defects:
1. the cylinder to be measured is small in mouth and big in belly, the light source can not directly irradiate, and images are difficult to directly acquire.
As can be seen from comparison and analysis, the detection of the position information of the cylindrical product by adopting any single method is difficult to meet the requirements of the detection of the inner wall and the outer wall of the cylindrical product.
SUMMERY OF THE UTILITY MODEL
The utility model discloses aim at overcoming prior art's weak point and provide a detection efficiency height, environmental influence factor is little, has the online formation of image detection device of higher measurement accuracy's drum inside and outside wall machining precision.
The purpose of the utility model is realized like this: on-line imaging detection device for machining precision of inner and outer walls of a cylinder, comprising: the device comprises a shell, a laser, a reflector, a light path conversion mirror and an image receiving and processing part; the laser, the reflector and the light path conversion mirror are assembled in the shell; the laser emitted by the laser is reflected by the reflector and then projected to the surface of the inner wall of the cylinder to be measured to form a diffuse reflection light spot; and the light path conversion mirror captures the diffuse reflection light spots and converges the diffuse reflection light spots to the image receiving and processing part for processing.
As a preferred scheme, the light path conversion mirror of the utility model selects a triple prism; the laser converted by the optical path conversion mirror is parallel to the incident light emitted by the laser.
As another preferred aspect, the image receiving and processing section of the present invention may include: the device comprises an image acquisition processing module, a digital signal processing module, a data storage module and a data transmission and display module; the image acquisition processing module acquires and processes the diffuse reflection light spot image; the digital signal processing module receives the data from the image acquisition processing module, performs operation processing, and then stores the related result in the data storage module; and the data transmission and display module displays the position information of the inner wall of the cylinder.
As a third preferred scheme, the utility model can be also provided with a USB interface, a network interface or a UART chip; and the UART chip and the digital signal processing module realize data exchange.
The utility model discloses have higher detection efficiency, can realize the automated inspection of the drum inside and outside wall degree of consistency to judge whether qualified drum. If the measured data is qualified, the measured data normally passes, if the measured data is not qualified, an alarm signal is sent, and meanwhile, the measured data can be reserved for inspection whether the measured data is qualified or not. Functionally, it can be roughly decomposed into three parts, including location of the inner wall point, location of the outer wall point, and fitting of the inner and outer wall point. In the working environment, the system can stably work for a long time under the harsh condition of high temperature. In the measurement index, the measurement precision and the measurement range meet the product requirement, and the measurement speed meets the working requirement of a production line.
Drawings
The present invention will be further described with reference to the accompanying drawings and the following detailed description. The scope of the present invention is not limited to the following description.
FIG. 1 is a schematic diagram of an object to be measured according to the present invention;
FIG. 2 is a schematic diagram of the principle of the laser triangulation method of the present invention;
FIG. 3 is a schematic view illustrating the principle of the optical path improvement of the present invention;
FIG. 4 is a model diagram of the system operation flow of the present invention;
FIG. 5 is a schematic view of the optical inspection part of the system of the present invention;
fig. 6 is a schematic diagram of the hardware structure of the system image receiving and processing part of the present invention;
fig. 7 is a schematic circuit diagram of the image receiving and processing part of the present invention.
Detailed Description
The utility model discloses consider that the method that adopts the non-contact avoids wearing and tearing corruption and high speed, the requirement of high accuracy, considers again that can not directly with the restriction of light irradiation, the system decision adopts one kind to combine together laser detection and visual detection to according to the method that the particularity of the target that awaits measuring improves, the laser triangle that has twice light path diversion detects the method and designs.
As shown in fig. 5, the system of the present invention includes: the device comprises a shell 1, a laser 2, a reflecting mirror 3, a light path conversion mirror 4 and an image receiving and processing part 5; the laser 2, the reflector 3 and the light path conversion mirror 4 are assembled in the shell 1; the laser emitted by the laser 2 is reflected by the reflector 3 and then projected to the surface of the inner wall of the cylinder to be measured to form a diffuse reflection light spot; the light path conversion mirror 4 captures the diffuse reflection light spot and converges the diffuse reflection light spot to an image receiving and processing part for processing. The light path conversion mirror 4 is a triangular prism; the laser light converted by the optical path conversion mirror 4 is parallel to the incident light emitted from the laser 2. The image reception processing section 5 includes: the device comprises an image acquisition processing module, a digital signal processing module, a data storage module and a data transmission and display module; the image acquisition processing module acquires and processes the diffuse reflection light spot image; the digital signal processing module receives the data from the image acquisition processing module, performs operation processing, and then stores the related result in the data storage module; and the data transmission and display module displays the position information of the inner wall of the cylinder. The utility model is also provided with a USB interface, a network interface and a UART chip; and the UART chip and the digital signal processing module realize data exchange.
The utility model discloses the realization of system's function mainly comprises the triplex, including the fitting of interior wall point position detection, outer wall point position detection, interior wall point position data. The detection of the position of the outer wall point is difficult and more methods are used due to the openness of the detection surface, and the detection is not taken as a main focus of research. The fitting of the position data of the inner wall point and the outer wall point is mature in research, research results are rich, and the fitting is not a main difficulty of research due to the fact that the fitting depends on the data acquisition of the position of the inner wall point and the position of the outer wall point to a great extent. The detection of the inner wall point is limited by time, space, environment and the like to the greatest extent, and is the key and difficult point for realizing the function. Therefore, the functional analysis and the model establishment are mainly based on the detection of the position of the inner wall point.
Due to limitations in cylinder profile, material and temperature, the detection of the position of points on the inner wall of the cylinder is the most complex part of the system. The analysis now starts from the characteristics of the cylinder of the object to be measured.
Cylinder shape characteristic
| Geometric dimension of the shape | Is integrally cylindrical Small mouth, large abdomen and bottom |
| Material and temperature | High temperature steel Through the punch forming of the precursor process, the surface temperature is very high The surface of the cylinder is covered with a black oxide layer |
| Inner wall inspection requirements | The inner wall position detection precision and the measuring range reach the product quality requirement The detection time requirement is as short as possible |
The cylinder is cylindrical as a whole, and the inner wall of the cylinder is a cylindrical surface which changes slightly irregularly. The horizontal cross section of the inner wall is circular, the point positions on the circumference can be sampled according to the radius direction to measure the circular shape, and then the circular shapes with different horizontal positions are used for fitting the cylindrical surface. The detection of the inner wall cylindrical surface can be simplified to the detection of the position of a point on the inner wall.
Due to the openness of the outer wall, the selection of the outer wall point position detection scheme is limited only by the remaining material, space and shape are not limited, and the selection range of the scheme is larger. In consideration of the convenience of fitting the data of the inner wall point and the outer wall point, the detection can be performed by adopting the same method as the inner wall point. In consideration of the openness of the detection of the outer wall points, methods such as parallel method and the like can be adopted to increase the number of sampling points and improve the measurement precision. Other simple and efficient methods are also contemplated. Here, detailed description is omitted.
Selection of system hardware working platform
Because the system requires high precision and high speed, a large amount of mathematical operations are required, and a strong operation platform is required. A high performance processor is required for data processing. The environmental condition of the system is very strict, and a general-purpose computer is difficult to meet the use requirement, so that an embedded microprocessor is selected for embedded development.
The embedded microprocessor has small appearance, is convenient for embedding a system and is also convenient for thermal insulation protection. The embedded microprocessor has low energy consumption and high efficiency, and is suitable for industrial detection.
On the basis of the strong operational capability of the embedded microprocessor, an image sensor is adopted to collect visual images. The image sensor can directly output digital image signals and integrates some basic image processing functions. The subsequent circuit design is simplified, and the image acquisition quality is improved.
The embedded microprocessor is combined with the image sensor to carry out hardware design, thereby saving space. Therefore, even isolation of the hardware system may be considered if system operating temperatures become an obstacle.
The inner wall point detection is designed by a method of combining laser detection and visual detection, improving according to the specificity of a target to be detected and a laser triangle detection method with light path turning. The working principle of the laser triangulation method is firstly analyzed, and then the method of the utility model is introduced.
1. Laser trigonometry theory of operation (as shown in figure 2)
The laser triangulation method is composed of a laser, a focusing lens, an imaging lens and a photoelectric sensor, wherein laser emitted by the laser is projected onto the surface of a measured object after passing through the focusing lens to form diffuse reflection light spots. The diffuse reflection light spot is used as a sensing signal, the collected reflection light is converged on a focal plane of an imaging lens by using a lens imaging principle, and a photoelectric sensor is arranged at the focal plane. When the diffuse reflection light spot moves along with the surface of the measured object, the imaging light spot correspondingly moves on the surface of the photoelectric sensor. The displacement of the surface of the measured object can be determined according to the size of the image shift distance and the structural parameters of the sensor, and the laser beam can be contacted with a measured mechanical probe to determine the position of a measured point on the measured surface. In order to reduce the influence of the measured surface quality on the measurement, a triangulation method is generally adopted in which a laser beam is perpendicularly incident on the surface of the measured object.
In the figure, s is the surface displacement of the object to be measured, s' is the relative displacement of the surface facula of the object to be measured on the sensor, a is the object distance from the lens to the object, b is the image distance from the lens to the imaging surface, and theta is the observation angle. The relationship of s' to s can be found from geometrical optics knowledge according to the relevant references as follows,
and when the measured distance is greater than the reference distance, a minus sign is taken, and when the measured distance is less than the reference distance, a plus sign is taken.
2. Principle analysis of light path improvement (as shown in FIG. 3)
Due to the limitation of the shape of the cylinder, the laser cannot irradiate the whole inner wall surface; because the cylinder temperature is high and the inner diameter is small, the laser triangulation device can not stretch into the cylinder for detection, so the basic laser triangulation scheme needs to be improved.
1. And reflecting the laser by using a reflector to change the light path of the laser. The detection device extends into the cylinder, the reflector is placed, and the light path of the laser incident parallel to the inner wall surface is changed to vertically irradiate the inner wall surface. This allows the laser to be placed vertically at a distance outside the cylinder.
2. A prism is used as an observation device to observe the imaging in the prism. Similarly, the detection device extends into the cylinder, and a prism for refracting the light path is arranged. Through the angle of the carefully designed prism, the visual image acquisition device can be vertically arranged outside the cylinder at a long distance to acquire images formed by the prism, so that the displacement of the laser diffusion spot can be observed.
The advantages of the above design:
1. the reflector placed at 45 degrees enables the laser light path to be perpendicular to the surface of the inner wall, so that the error of laser triangulation detection can be reduced, and calculation is facilitated.
2. The two reflections generated in the triangular prism are all total reflections, so that on one hand, theoretically, no reflected light energy is lost, and on the other hand, on the optical theory, the real image finally formed by the triangular prism has the same size and direction as an actual object, and only the relative distance is changed slightly.
And designing a system working model according to an improved laser triangulation detection method with two light path changes. The system workflow model is shown in fig. 4.
The cylinder moves on the production line conveyor belt, stops after reaching the position of the detection device, and performs detection. The detection device stretches into the cylinder for detection, and after detection is finished, the device is pulled out. And if the detection result is qualified, informing the conveyor belt to continue to move forward to prepare for detecting the next cylinder. And if the detection result is not qualified, alarming, informing the precursor process and checking the working process. According to the application requirement, the detection device can be linked with other systems in the factory through a network; the test data may also be retained for review.
As shown in fig. 5, the optical detection portion is responsible for irradiating laser light perpendicularly to the inner wall surface and imaging the optical image onto the sensitive surface of the image acquisition system. The laser imaging device comprises a laser for emitting laser, a reflecting mirror for refracting the laser, a triple prism for observing an image, a lens required by focusing and imaging, and a shell for loading and fixing each device. The optical detection part not only realizes the functions of imaging and transmission, but also plays a role in positioning and fixing, and is directly related to the positioning precision of the system. The optical detection portion is also required to ensure an appropriate working distance so that the circuit portion can operate under normal circumstances.
The circuit part (fig. 6 and 7) is mainly responsible for digital acquisition and processing of images. The method mainly comprises the steps of image acquisition, program storage and image and control information processing.
The laser beam irradiates the surface of the inner wall to modulate the position information and generate original image information. The position information is integrated into the image information and then transmitted in the form of an image in the optical system, where the image is transmitted as a carrier of the position information. At a receiving end, the received image information is not completely consistent with the original image information, some of the received image information is loss change in transmission, and some of the received image information is interference noise in the transmission process. After the digital image is obtained by sampling and quantizing the digital image by a sensor, the position information is demodulated by further image processing.
Claims (6)
1. On-line imaging detection device of drum inner and outer wall machining precision, its characterized in that includes: the device comprises a shell (1), a laser (2), a reflecting mirror (3), a light path conversion mirror (4) and an image receiving and processing part (5); the laser device (2), the reflector (3) and the light path conversion mirror (4) are assembled in the shell (1); laser emitted by the laser (2) is reflected by the reflector (3) and then projected to the surface of the inner wall of the cylinder to be measured to form a diffuse reflection light spot; and the light path conversion mirror (4) captures the diffuse reflection light spots and converges the diffuse reflection light spots to the image receiving and processing part for processing.
2. The on-line imaging detection device for processing accuracy of inner and outer walls of a cylinder according to claim 1, wherein: the light path conversion mirror (4) is a triangular prism; the laser converted by the light path conversion mirror (4) is parallel to the incident light emitted by the laser (2).
3. The on-line imaging detection device for processing accuracy of inner and outer walls of a cylinder according to claim 1 or 2, wherein: the image reception processing section (5) includes: the device comprises an image acquisition processing module, a digital signal processing module, a data storage module and a data transmission and display module; the image acquisition and processing module acquires and processes the diffuse reflection light spot image; the digital signal processing module receives the data from the image acquisition processing module, performs operation processing, and then stores the related result in the data storage module; and the data transmission and display module displays the position information of the inner wall of the cylinder.
4. The on-line imaging detection device for processing accuracy of inner and outer walls of a cylinder according to claim 1 or 2, wherein: and is also provided with a USB interface or a network interface.
5. The on-line imaging detection device for processing accuracy of inner and outer walls of a cylinder according to claim 3, wherein: and is also provided with a USB interface or a network interface.
6. The on-line imaging detection device for processing accuracy of inner and outer walls of a cylinder according to claim 5, wherein: a UART chip is also arranged; and the UART chip and the digital signal processing module realize data exchange.
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| CNU200620168791XU CN201034557Y (en) | 2006-12-31 | 2006-12-31 | Cylinder inside and outside wall machine precision on-line image-forming testing apparatus |
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| Application Number | Priority Date | Filing Date | Title |
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| CNU200620168791XU CN201034557Y (en) | 2006-12-31 | 2006-12-31 | Cylinder inside and outside wall machine precision on-line image-forming testing apparatus |
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| CN201034557Y true CN201034557Y (en) | 2008-03-12 |
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| CNU200620168791XU Expired - Fee Related CN201034557Y (en) | 2006-12-31 | 2006-12-31 | Cylinder inside and outside wall machine precision on-line image-forming testing apparatus |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102016499B (en) * | 2008-05-01 | 2012-12-05 | 株式会社普利司通 | Device and method for measuring object to be measured having hollow circular cylindrical shape, and device for inspecting external appearance of tire |
| CN105091678A (en) * | 2014-05-20 | 2015-11-25 | 中国能源建设集团有限公司工程研究院 | Automatic hole searching method, device and system for all-dimensional explosive filling in underground explosion |
-
2006
- 2006-12-31 CN CNU200620168791XU patent/CN201034557Y/en not_active Expired - Fee Related
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102016499B (en) * | 2008-05-01 | 2012-12-05 | 株式会社普利司通 | Device and method for measuring object to be measured having hollow circular cylindrical shape, and device for inspecting external appearance of tire |
| CN105091678A (en) * | 2014-05-20 | 2015-11-25 | 中国能源建设集团有限公司工程研究院 | Automatic hole searching method, device and system for all-dimensional explosive filling in underground explosion |
| CN105091678B (en) * | 2014-05-20 | 2017-03-29 | 中国能源建设集团有限公司工程研究院 | A kind of comprehensive powder charge automatic seeking hole method of underground explosion, apparatus and system |
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Granted publication date: 20080312 Termination date: 20100201 |