CN106705857A - Automatic monitoring system of laser surface displacement - Google Patents
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Abstract
本发明公开了一种激光表面位移自动监测系统,涉及一种激光表面位移自动监测系统是满足岩土工程信息化施工需要的监测设备,包括以下步骤:步骤1、监测系统的基本技术原理,步骤2、监测系统的标定,步骤3、评估位移测量精度,步骤4、测量装置的设计;本发明的目的是通过获取激光点投射在靶板上的光点的精确坐标的变化量得到安装激光器的表面位移变化,解决了在基坑工程、隧道工程监测中量大面广的表面位移监测问题。
The invention discloses a laser surface displacement automatic monitoring system, and relates to a laser surface displacement automatic monitoring system, which is a monitoring device that meets the needs of geotechnical engineering information construction, including the following steps: Step 1, the basic technical principle of the monitoring system, step 2, the demarcation of monitoring system, step 3, evaluation displacement measurement accuracy, step 4, the design of measuring device; The purpose of the present invention is to obtain the installation laser by obtaining the variation of the precise coordinates of the light spot projected on the target plate by the laser spot The surface displacement change solves the problem of surface displacement monitoring with a large amount and a wide area in the monitoring of foundation pit engineering and tunnel engineering.
Description
技术领域technical field
本发明属于自动监测系统技术领域,涉及一种激光表面位移自动监测系统,适用于在基坑工程、隧道工程监测中量大面广的表面位移监测问题。The invention belongs to the technical field of automatic monitoring systems, and relates to a laser surface displacement automatic monitoring system, which is suitable for the monitoring of large-scale and wide-ranging surface displacements in the monitoring of foundation pit engineering and tunnel engineering.
背景技术Background technique
目前,岩土工程监测主要以人工测量手段为主,虽然有静力水准仪等自动监测仪器,但市场价格昂贵,使得在岩土工程实践中,无法大量推广使用。如果能够开发价格适中,能够满足岩土工程信息化施工需要的监测设备,其市场前景是巨大的。At present, the monitoring of geotechnical engineering is mainly based on manual measurement methods. Although there are automatic monitoring instruments such as static levels, the market price is too high, which makes it impossible to widely promote and use them in geotechnical engineering practice. If the monitoring equipment can be developed at a moderate price and can meet the needs of geotechnical engineering information construction, its market prospect is huge.
因此,整体考虑采用嵌入式系统开发能在线智能读取位移值的传感系统。对于读取激光点在靶板上的坐标,经过调研,有几种技术途径,一种是采用PSD或CCD感光芯片直接读取感光点坐标,这种方法造价较高。还有一种是采用精密加工方法将光纤构成阵列,然后采用阵列扫描读取感光点坐标,这种方法加工难度较大。最后一种方法是直接采用摄像头对感光靶板拍照,采用摄影测量方法读取坐标。最后一种方法造价较低,也必将易于实现,拟采用这种方法进行自动监测系统的研制。Therefore, the overall consideration is to use the embedded system to develop a sensor system that can intelligently read the displacement value online. For reading the coordinates of the laser point on the target plate, after investigation, there are several technical approaches, one is to use PSD or CCD photosensitive chip to directly read the coordinates of the photosensitive point, this method is relatively expensive. Another method is to use precision processing to form an array of optical fibers, and then use array scanning to read the coordinates of the photosensitive points. This method is more difficult to process. The last method is to directly use the camera to take pictures of the photosensitive target plate, and use the photogrammetry method to read the coordinates. The last method has lower cost and will be easy to realize. It is planned to use this method to develop the automatic monitoring system.
发明内容Contents of the invention
本发明所要解决的技术问题是,克服现有技术的缺点,提供一种激光表面位移自动监测系统,本发明的目的是通过获取激光点投射在靶板上的光点的精确坐标的变化量得到安装激光器的表面位移变化,解决了在基坑工程、隧道工程监测中量大面广的表面位移监测问题。The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a laser surface displacement automatic monitoring system. The purpose of the present invention is to obtain The surface displacement change of the installed laser solves the problem of large-scale and wide-ranging surface displacement monitoring in foundation pit engineering and tunnel engineering monitoring.
为了解决以上技术问题,本发明提供一种激光表面位移自动监测系统,包括以下步骤:In order to solve the above technical problems, the present invention provides a laser surface displacement automatic monitoring system, comprising the following steps:
步骤(一)、监测系统的基本技术原理;Step (1), the basic technical principle of the monitoring system;
利用激光的准直性,当A点激光射向B点时,B点的靶板上就存在一个光斑,如果B点(基准点)静止不动,当A点发生位移时,靶板上的光斑也相应发生移动。精确测量靶板上光点的坐标,即可获得A点位移的大小。并且可以在水平位移和垂直位移两个方向上获得位移值。Using the collimation of the laser, when the laser at point A shoots to point B, there is a spot on the target board at point B. If point B (reference point) is stationary, when point A is displaced, the spot on the target board The spot also moves accordingly. Accurately measure the coordinates of the light spot on the target plate to obtain the displacement of point A. And the displacement value can be obtained in two directions of horizontal displacement and vertical displacement.
关闭激光器,获取没有光点的靶板RGB彩色图像照片,打开激光器,获取带光点的靶板RGB彩色图像照片,使用的摄像头像素为2592×1944。Turn off the laser, get the RGB color image photo of the target plate without light spots, turn on the laser, and get the RGB color image photo of the target plate with light spots, the camera pixel used is 2592×1944.
将两张靶板RGB彩色图像照片分别进行灰度化处理。The two RGB color image photos of the target plate were processed in grayscale respectively.
将处理后的灰度图片进行相减操作,由于两幅图像仅有亮点处的图像不同,在相减操作之后,会出现明显的灰度差异。Subtract the processed grayscale images. Since the two images are only different in the bright spots, there will be obvious grayscale differences after the subtraction operation.
对此灰度图像照片进行图像二值化处理,二值化阈值为最亮点灰度值的80%,得到的二值化图像。The image binarization process is performed on this grayscale image photo, and the binarization threshold is 80% of the grayscale value of the brightest point to obtain a binarized image.
在一般情况下,激光器所打的圆斑亮点是不规则的,为了准确打到光点的坐标位置,使用腐蚀算法将二值化图像进行腐蚀,为了加快腐蚀算法,根据实验的先验知识可知,激光器的光斑亮点像素不大于301×301,并进行图像截取;截取后的二值化图像像素大小不大于301×301。Under normal circumstances, the bright spots of the round spot hit by the laser are irregular. In order to accurately hit the coordinate position of the light spot, the binary image is corroded using the corrosion algorithm. In order to speed up the corrosion algorithm, according to the prior knowledge of the experiment, it can be known that , the pixel of the bright spot of the laser is not greater than 301×301, and the image is intercepted; the pixel size of the binary image after interception is not greater than 301×301.
此时,使用腐蚀算法对二值化图像进行腐蚀,选取腐蚀矩阵如式所示:At this time, use the corrosion algorithm to corrode the binarized image, and select the corrosion matrix as shown in the formula:
每次腐蚀后,若图像不全为0,则覆盖前一次图像,若图像为全0,则停止腐蚀,不覆盖原图像。After each erosion, if the image is not all 0, the previous image will be covered; if the image is all 0, the corrosion will be stopped without covering the original image.
将图像中的亮点像素坐标取平均值,即得到激光器打在靶板上的坐标。The pixel coordinates of the bright spots in the image are averaged to obtain the coordinates of the laser hitting the target.
多次得到激光器射线在靶板上的坐标,即可测量得到安装激光器的结构表面位移。The coordinates of the laser rays on the target plate are obtained many times, and the surface displacement of the structure on which the laser is installed can be measured.
步骤(二)、监测系统的标定;Step (2), calibration of the monitoring system;
监测系统的标定包括两个部分,第一是靶板的透视标定,第二是像素与距离的标定。The calibration of the monitoring system includes two parts, the first is the perspective calibration of the target plate, and the second is the calibration of pixels and distances.
(1)靶板的透视标定(1) Perspective calibration of the target plate
靶板和测量摄像头安装在测量盒上,由于工艺的原因,靶板和摄像头拍摄面无法完全平行,因此该测量装置在制作完成后需要进行透视标定。The target board and the measurement camera are installed on the measurement box. Due to the process, the target board and the camera shooting surface cannot be completely parallel, so the measurement device needs to be calibrated in perspective after the production is completed.
在制作靶板的过程中,已经贴了一层标准距离的方格纸,间距为10mm,在得到靶板照片之后,可使用四点透视法获取透视变换系数,透视变换的过程如下:In the process of making the target board, a layer of graph paper with a standard distance has been pasted with a spacing of 10mm. After getting the target board photo, the perspective transformation coefficient can be obtained by using the four-point perspective method. The perspective transformation process is as follows:
(a)、选取靶板照片上任意一个正方形的四个顶点,依次是左上,右上,左下,右下,获取其像素坐标(xZS,yZS),(xYS,yYS),(xZX,yZX),(xYX,yYX);(a), select the four vertices of any square on the target plate photo, which are upper left, upper right, lower left, and lower right in turn, and obtain its pixel coordinates (xZS, yZS), (xYS, yYS), (xZX, yZX), (xYX, yYX);
(b)、根据式从原四边形获得新矩形宽和高;(b), obtain new rectangle width and height from original quadrilateral according to formula;
则变换后的四个顶点坐标如式所示:Then the transformed coordinates of the four vertices are as follows:
(c)、令B=[X(1),Y(1),X(2),Y(2),X(3),Y(3),X(4),Y(4)]T,解如式所示的矩阵方程:(c), let B=[X(1), Y(1), X(2), Y(2), X(3), Y(3), X(4), Y(4)] T , Solve the matrix equation shown as:
令make
得到透视变换系数如式所示:The perspective transformation coefficient is obtained as shown in the formula:
Xi=inv(A)·B \*MERGEFORMAT (6)Xi=inv(A)·B \*MERGEFORMAT (6)
其中,Xi为8×1阶矩阵,从而得到变换系数如式所示:Among them, Xi is an 8 × 1-order matrix, so that the transformation coefficients are obtained as shown in the formula:
(d)、假设腐蚀算法得出的光点坐标为(x0,y0),则需要按照式进行透视变换,得到最终坐标。(d) Assuming that the coordinates of the light point obtained by the erosion algorithm are (x 0 , y 0 ), it is necessary to perform perspective transformation according to the formula to obtain the final coordinates.
至此,完成了透视变换。At this point, the perspective transformation is completed.
(2)像素距离的标定(2) Calibration of pixel distance
在靶板的透视标定结束后,需要得到像素距离和实际距离的对应关系,根据靶板上的标准线,选取已经距离的两点坐标(x1o,y1o),(x2o,y2o),已知其距离为L,利用变换系数将其坐标变换为(x1,y1),(x2,y2),则距离标定系数如式所示:After the perspective calibration of the target board is completed, it is necessary to obtain the corresponding relationship between the pixel distance and the actual distance. According to the standard line on the target board, select the two point coordinates (x 1o , y 1o ), (x 2o , y 2o ) , its distance is known as L, and its coordinates are transformed into (x 1 , y 1 ), (x 2 , y 2 ) by using the transformation coefficient, then the distance calibration coefficient is shown in the formula:
根据此系数,可以得到两次激光器光对的移动距离。According to this coefficient, the moving distance of the two laser light pairs can be obtained.
步骤(三)、评估位移测量精度;Step (3), evaluating displacement measurement accuracy;
测量摄像头拍摄像素为2592×1944,靶板尺寸为133mm×100mm,两者比例如式所式:The shooting pixels of the measurement camera are 2592×1944, and the size of the target plate is 133mm×100mm. The ratio of the two is as follows:
因此,从理论上看,每两点的像素距离为100/1944<0.052mm,考虑光斑的重心坐标寻找和安装误差等影响,该测量装置位移测量精度需要在实际的稳定性测试中确定。Therefore, theoretically, the pixel distance between each two points is 100/1944<0.052mm. Considering the influence of spot center of gravity coordinate search and installation error, the displacement measurement accuracy of the measuring device needs to be determined in the actual stability test.
步骤(四)、测量装置的设计;Step (4), the design of measuring device;
(1)、测量盒体的设计(1), the design of the measuring box
测量盒体材质使用6061-T6合金铝,属热处理可强化合金,具有良好的可成型性、可焊接性、可机加工性,同时具有中等强度,在退火后仍能维持较好的操作性,密度小质量轻,防腐蚀易安装。The material of the measurement box is 6061-T6 alloy aluminum, which is heat-treated and strengthenable alloy. It has good formability, weldability, machinability, and medium strength. It can still maintain good operability after annealing. Low density, light weight, anti-corrosion and easy to install.
盒体采用拼装结构,主体由六块板材组成。The box body adopts an assembled structure, and the main body is composed of six plates.
盒体内部安装可调节支架,使用卡槽设计,用于安装测量摄像头。盒体两端采用插槽设计,用于插入拍摄靶板。An adjustable bracket is installed inside the box, which is designed with a card slot for installing the measurement camera. Both ends of the box body are designed with slots for inserting the shooting target board.
(2)、测量靶板的设计(2) Design of measurement target board
测量靶板的材质使用市面上常见的有机塑料板制作,板材厚度2mm,白色,透光微透明。该有机塑料板具有优良的韧性和尺寸稳定性,绝缘性能可靠、耐热性能好,耐酸碱、抗化学腐蚀,极易加工,并且无毒环保、经久耐用。可在其上面贴覆一层标准距离方格的塑料,用于测量系统的标定。The material of the measurement target plate is made of common organic plastic plate on the market, the thickness of the plate is 2mm, it is white, light-transmitting and slightly transparent. The organic plastic board has excellent toughness and dimensional stability, reliable insulation performance, good heat resistance, acid and alkali resistance, chemical corrosion resistance, easy processing, non-toxic, environmentally friendly and durable. A layer of plastic with a standard distance grid can be pasted on it for calibration of the measuring system.
(3)、测量硬件的设计(3) Design of measurement hardware
测量硬件使用Raspberry Pi卡片式电脑B型Rev1,它的体积仅有信用卡般大小,具有视频、网络、IO等功能。The measurement hardware uses a Raspberry Pi card computer type B Rev1, which is only the size of a credit card and has functions such as video, network, and IO.
在Raspberry Pi平台进行每一次测量所运行的时间约为5秒,表明测量频率可达到0.2Hz,在实际的基坑、隧道等表面位移的测量中,由于表面位移变化的非常缓慢,该测量频率完全满足测量要求。The running time of each measurement on the Raspberry Pi platform is about 5 seconds, indicating that the measurement frequency can reach 0.2Hz. In the actual measurement of the surface displacement of foundation pits, tunnels, etc., because the surface displacement changes very slowly, the measurement frequency Fully meet the measurement requirements.
本发明的有益效果是:本发明设计的方法实现了适用于在基坑工程、隧道工程监测中量大面广的表面位移自动监测系统,降低了监测成本,可无人值守自动获取表面位移信息,是基坑工程、隧道工程监测技术领域的重大进步。The beneficial effect of the present invention is: the method designed by the present invention realizes the surface displacement automatic monitoring system suitable for large-scale and wide-area monitoring in foundation pit engineering and tunnel engineering, reduces the monitoring cost, and can automatically obtain surface displacement information without being on duty It is a major progress in the field of foundation pit engineering and tunnel engineering monitoring technology.
附图说明Description of drawings
图1为本发明的原理流程图;Fig. 1 is a principle flow chart of the present invention;
图2为监测系统的基本技术原理示意图;Figure 2 is a schematic diagram of the basic technical principle of the monitoring system;
图3(a)为关闭激光器所获取的靶板RGB彩色图像照片;Figure 3(a) is a photo of the RGB color image of the target plate obtained by turning off the laser;
图3(b)为打开激光器所获取的靶板RGB彩色图像照片;Fig. 3 (b) is the RGB color image photo of the target plate obtained by turning on the laser;
图4(a)为关闭激光器所获取的靶板灰度图像照片;Fig. 4 (a) is the photo of the grayscale image of the target plate obtained by turning off the laser;
图4(b)为打开激光器所获取的靶板灰度图像照片;Fig. 4 (b) is the photo of the grayscale image of the target plate obtained by turning on the laser;
图5为相减算法后的靶板灰度图像照片;Fig. 5 is the photo of the grayscale image of the target plate after the subtraction algorithm;
图6为二值化图像处理结果;Fig. 6 is the binary image processing result;
图7为取光斑范围步骤流程图;Fig. 7 is the flow chart of taking the steps of spot range;
图8为截取后的光斑区域二值化图片;Fig. 8 is the binarized image of the spot area after interception;
图9为腐蚀算法过程图片;Figure 9 is a picture of the corrosion algorithm process;
图10(a)为理想中的靶板与摄像头拍摄面平行照片;Figure 10 (a) is a parallel photo of the ideal target plate and the camera shooting surface;
图10(b)为实际靶板与摄像头拍摄面不平行照片;Fig. 10(b) is a photo that the actual target plate is not parallel to the photographing surface of the camera;
图11为测量盒体拼装图;Figure 11 is an assembly diagram of the measurement box;
图12为测量盒体可调摄像头支架卡槽设计;Figure 12 shows the design of the slot for the adjustable camera bracket of the measurement box;
图13为测量硬件结构框图;Fig. 13 is a block diagram of the measurement hardware structure;
图14为测量硬件自动运行程序框图;Figure 14 is a block diagram of the automatic operation of the measurement hardware;
图15为监测系统流程;Figure 15 is the monitoring system flow;
图16(a)为稳定性测试结果点状图;Fig. 16 (a) is the point diagram of stability test result;
图16(b)为稳定性测试结果柱状图;Figure 16(b) is a histogram of the stability test results;
图17为位移台正方形路径测量结果示意图。Figure 17 is a schematic diagram of the measurement results of the square path of the displacement platform.
具体实施方式detailed description
实施例1Example 1
本实施例提供一种激光表面位移自动监测系统,原理如图1所示,包括以下步骤:This embodiment provides an automatic monitoring system for laser surface displacement, the principle of which is shown in Figure 1, including the following steps:
步骤(一)、监测系统的基本技术原理;Step (1), the basic technical principle of the monitoring system;
如图2所示,利用激光的准直性,当A点激光射向B点时,B点的靶板上就存在一个光斑,如果B点(基准点)静止不动,当A点发生位移时,靶板上的光斑也相应发生移动。精确测量靶板上光点的坐标,即可获得A点位移的大小。并且可以在水平位移和垂直位移两个方向上获得位移值。As shown in Figure 2, using the collimation of the laser, when the laser at point A is directed at point B, there is a spot on the target plate at point B. If point B (reference point) is stationary, when point A is displaced , the light spot on the target plate also moves accordingly. Accurately measure the coordinates of the light spot on the target plate to obtain the displacement of point A. And the displacement value can be obtained in two directions of horizontal displacement and vertical displacement.
关闭激光器,获取没有光点的靶板RGB彩色图像照片,如图3(a)所示,打开激光器,获取带光点的靶板RGB彩色图像照片,如3(b)所示,使用的摄像头像素为2592×1944。Turn off the laser and obtain the RGB color image photo of the target plate without light spots, as shown in Figure 3(a), turn on the laser, and obtain the RGB color image photo of the target plate with light spots, as shown in Figure 3(b), the camera used The pixels are 2592×1944.
将两张靶板RGB彩色图像照片分别进行灰度化处理,如图4(a)和图4(b)所示。The two RGB color image photos of the target plate were processed in grayscale respectively, as shown in Fig. 4(a) and Fig. 4(b).
将处理后的灰度图片进行相减操作,由于两幅图像仅有亮点处的图像不同,在相减操作之后,会出现明显的灰度差异,如图5所示。Subtract the processed grayscale images. Since the two images are only different in the bright spots, after the subtraction operation, there will be obvious grayscale differences, as shown in Figure 5.
对此灰度图像照片进行图像二值化处理,二值化阈值为最亮点灰度值的80%,得到的二值化图像如图6所示。Image binarization is performed on this grayscale image photo, and the binarization threshold is 80% of the grayscale value of the brightest point. The obtained binarized image is shown in Figure 6.
在一般情况下,激光器所打的圆斑亮点是不规则的,为了准确打到光点的坐标位置,使用腐蚀算法将二值化图像进行腐蚀,为了加快腐蚀算法,根据实验的先验知识可知,激光器的光斑亮点像素不大于301×301,可按图7所示方法进行图像截取。Under normal circumstances, the bright spots of the round spot hit by the laser are irregular. In order to accurately hit the coordinate position of the light spot, the binary image is corroded using the corrosion algorithm. In order to speed up the corrosion algorithm, according to the prior knowledge of the experiment, it can be known that , the pixel of the bright spot of the laser is not larger than 301×301, and the image can be intercepted according to the method shown in Figure 7.
截取后的二值化图像像素大小不大于301×301,如图8所示。The pixel size of the intercepted binarized image is not larger than 301×301, as shown in Figure 8.
此时,使用腐蚀算法对二值化图像进行腐蚀,选取腐蚀矩阵如式所示:At this time, use the corrosion algorithm to corrode the binarized image, and select the corrosion matrix as shown in the formula:
每次腐蚀后,若图像不全为0,则覆盖前一次图像,若图像为全0,则停止腐蚀,不覆盖原图像,如图9所示。After each corrosion, if the image is not all 0, then cover the previous image, if the image is all 0, then stop the corrosion, do not cover the original image, as shown in Figure 9.
将图像中的亮点像素坐标取平均值,即得到激光器打在靶板上的坐标。The pixel coordinates of the bright spots in the image are averaged to obtain the coordinates of the laser hitting the target.
多次得到激光器射线在靶板上的坐标,即可测量得到安装激光器的结构表面位移。The coordinates of the laser rays on the target plate are obtained many times, and the surface displacement of the structure on which the laser is installed can be measured.
步骤(二)、监测系统的标定;Step (2), calibration of the monitoring system;
监测系统的标定包括两个部分,第一是靶板的透视标定,第二是像素与距离的标定。The calibration of the monitoring system includes two parts, the first is the perspective calibration of the target plate, and the second is the calibration of pixels and distances.
(1)靶板的透视标定(1) Perspective calibration of the target plate
靶板和测量摄像头安装在测量盒上,由于工艺的原因,靶板和摄像头拍摄面无法完全平行,如图10所示,因此该测量装置在制作完成后需要进行透视标定。The target board and the measurement camera are installed on the measurement box. Due to the process, the target board and the camera shooting surface cannot be completely parallel, as shown in Figure 10. Therefore, the measurement device needs to be calibrated in perspective after the production is completed.
在制作靶板的过程中,已经贴了一层标准距离的方格纸,间距为10mm,在得到靶板照片之后,可使用四点透视法获取透视变换系数,透视变换的过程如下:In the process of making the target board, a layer of graph paper with a standard distance has been pasted with a spacing of 10mm. After getting the target board photo, the perspective transformation coefficient can be obtained by using the four-point perspective method. The perspective transformation process is as follows:
(a)、选取靶板照片上任意一个正方形的四个顶点,依次是左上,右上,左下,右下,获取其像素坐标(xZS,yZS),(xYS,yYS),(xZX,yZX),(xYX,yYX);(a), select the four vertices of any square on the target plate photo, which are upper left, upper right, lower left, and lower right in turn, and obtain its pixel coordinates (xZS, yZS), (xYS, yYS), (xZX, yZX), (xYX, yYX);
(b)、根据式从原四边形获得新矩形宽和高;(b), obtain new rectangle width and height from original quadrilateral according to formula;
则变换后的四个顶点坐标如式所示:Then the transformed coordinates of the four vertices are as follows:
(c)、令B=[X(1),Y(1),X(2),Y(2),X(3),Y(3),X(4),Y(4)]T,解如式所示的矩阵方程:(c), let B=[X(1), Y(1), X(2), Y(2), X(3), Y(3), X(4), Y(4)] T , Solve the matrix equation shown as:
令make
得到透视变换系数如式所示:The perspective transformation coefficient is obtained as shown in the formula:
Xi=inv(A)·B \*MERGEFORMAT (6)Xi=inv(A)·B \*MERGEFORMAT (6)
其中,Xi为8×1阶矩阵,从而得到变换系数如式所示:Among them, Xi is an 8 × 1-order matrix, so that the transformation coefficients are obtained as shown in the formula:
(d)、假设腐蚀算法得出的光点坐标为(x0,y0),则需要按照式进行透视变换,得到最终坐标。(d) Assuming that the coordinates of the light point obtained by the erosion algorithm are (x 0 , y 0 ), it is necessary to perform perspective transformation according to the formula to obtain the final coordinates.
至此,完成了透视变换。At this point, the perspective transformation is completed.
(2)像素距离的标定(2) Calibration of pixel distance
在靶板的透视标定结束后,需要得到像素距离和实际距离的对应关系,根据靶板上的标准线,选取已经距离的两点坐标(x1o,y1o),(x2o,y2o),已知其距离为L,利用变换系数将其坐标变换为(x1,y1),(x2,y2),则距离标定系数如式所示:After the perspective calibration of the target board is completed, it is necessary to obtain the corresponding relationship between the pixel distance and the actual distance. According to the standard line on the target board, select the two point coordinates (x 1o , y 1o ), (x 2o , y 2o ) , its distance is known as L, and its coordinates are transformed into (x 1 , y 1 ), (x 2 , y 2 ) by using the transformation coefficient, then the distance calibration coefficient is shown in the formula:
根据此系数,可以得到两次激光器光对的移动距离。According to this coefficient, the moving distance of the two laser light pairs can be obtained.
步骤(三)、评估位移测量精度;Step (3), evaluating displacement measurement accuracy;
测量摄像头拍摄像素为2592×1944,靶板尺寸为133mm×100mm,两者比例如式所式:The shooting pixels of the measurement camera are 2592×1944, and the size of the target plate is 133mm×100mm. The ratio of the two is as follows:
因此,从理论上看,每两点的像素距离为100/1944<0.052mm,考虑光斑的重心坐标寻找和安装误差等影响,该测量装置位移测量精度需要在实际的稳定性测试中确定。Therefore, theoretically, the pixel distance between each two points is 100/1944<0.052mm. Considering the influence of spot center of gravity coordinate search and installation error, the displacement measurement accuracy of the measuring device needs to be determined in the actual stability test.
步骤(四)、测量装置的设计;Step (4), the design of measuring device;
(1)、测量盒体的设计(1), the design of the measuring box
测量盒体材质使用6061-T6合金铝,属热处理可强化合金,具有良好的可成型性、可焊接性、可机加工性,同时具有中等强度,在退火后仍能维持较好的操作性,密度小质量轻,防腐蚀易安装。The material of the measurement box is 6061-T6 alloy aluminum, which is heat-treated and strengthenable alloy. It has good formability, weldability, machinability, and medium strength. It can still maintain good operability after annealing. Small density, light weight, anti-corrosion and easy to install.
盒体采用拼装结构,主体由六块板材组成,如图11所示。The box body adopts an assembled structure, and the main body is composed of six plates, as shown in Figure 11.
盒体内部安装可调节支架,使用卡槽设计,用于安装测量摄像头。盒体两端采用插槽设计,用于插入拍摄靶板;如图12所示。An adjustable bracket is installed inside the box, which is designed with a card slot for installing the measurement camera. Both ends of the box are designed with slots for inserting the shooting target board; as shown in Figure 12.
(2)、测量靶板的设计(2) Design of measurement target board
测量靶板的材质使用市面上常见的有机塑料板制作,板材厚度2mm,白色,透光微透明。该有机塑料板具有优良的韧性和尺寸稳定性,绝缘性能可靠、耐热性能好,耐酸碱、抗化学腐蚀,极易加工,并且无毒环保、经久耐用。可在其上面贴覆一层标准距离方格的塑料,用于测量系统的标定。The material of the measurement target plate is made of common organic plastic plate on the market, the thickness of the plate is 2mm, white, slightly transparent. The organic plastic board has excellent toughness and dimensional stability, reliable insulation performance, good heat resistance, acid and alkali resistance, chemical corrosion resistance, easy processing, non-toxic, environmentally friendly and durable. A layer of plastic with a standard distance grid can be pasted on it for calibration of the measuring system.
(3)、测量硬件的设计(3) Design of measurement hardware
测量硬件使用Raspberry Pi卡片式电脑B型Rev1,它的体积仅有信用卡般大小,具有视频、网络、IO等功能,硬件框图如图13所示。The measurement hardware uses Raspberry Pi card type computer B-type Rev1, which is only the size of a credit card and has functions such as video, network, and IO. The hardware block diagram is shown in Figure 13.
如图14所示,在Raspberry Pi平台进行每一次测量所运行的时间约为5秒,表明测量频率可达到0.2Hz,在实际的基坑、隧道等表面位移的测量中,由于表面位移变化的非常缓慢,该测量频率完全满足测量要求。As shown in Figure 14, the running time for each measurement on the Raspberry Pi platform is about 5 seconds, indicating that the measurement frequency can reach 0.2 Hz. Very slowly, this measurement frequency fully meets the measurement requirements.
以下将结合附图15-17对本发明的技术方案进行详细描述:The technical solution of the present invention will be described in detail below in conjunction with accompanying drawings 15-17:
流程如图15所示,首先要制作出测量盒和靶板,然后在Raspberry Pi上烧录好编写的测量程序,确定好摄像头与靶板的距离,搭建好测量平台,接着拍摄初始照片,做透视变换求解标定因子,确定像素距离与实验距离的关系,最后进行稳定性测试,得到实际的测量精度。The process is shown in Figure 15. Firstly, the measurement box and the target board should be produced, and then the written measurement program should be burned on the Raspberry Pi, the distance between the camera and the target board should be determined, the measurement platform should be built, and then the initial photos should be taken. The perspective transformation is used to solve the calibration factor, determine the relationship between the pixel distance and the experimental distance, and finally conduct a stability test to obtain the actual measurement accuracy.
以下将通过具体的算例对本发明的技术方案中激光像素点的坐标提取实现过程予以说明。The implementation process of coordinate extraction of laser pixel points in the technical solution of the present invention will be described below through specific calculation examples.
测量盒安装完毕后,即可进行透视变换标定,解算出变换因子,确定出像素距离与实际距离的关系。任意取一个正方形的四个顶点,最终解算出透视变换因子为:After the measurement box is installed, the perspective transformation calibration can be carried out, the transformation factor can be calculated, and the relationship between the pixel distance and the actual distance can be determined. Randomly take four vertices of a square, and finally calculate the perspective transformation factor as:
a=0.96142384a=0.96142384
b=0.00401253b=0.00401253
c=168.45083955c=168.45083955
d=-0.01557080d=-0.01557080
e=0.98860270e=0.98860270
f=-149.21030551f=-149.21030551
g=-0.00001872g=-0.00001872
h=0.00000839h=0.00000839
同时得出每相邻两像素间的实际距离为0.04755435mmAt the same time, the actual distance between every two adjacent pixels is 0.04755435mm
将这些参数和测量程序导入测量硬件中,即完成了测量硬件软件的准备工作。Importing these parameters and measurement programs into the measurement hardware completes the preparation of the measurement hardware and software.
在该激光表面位移自动监测系统的安装过程中,对安装条件有以下限定:During the installation process of the laser surface displacement automatic monitoring system, the installation conditions are limited as follows:
激光与测量盒间距离不宜超过10米,距离太远则难以将激光器光点调整至靶板上,激光出现些微扭动光点即飞出靶板。The distance between the laser and the measuring box should not exceed 10 meters. If the distance is too far, it will be difficult to adjust the laser light spot to the target plate. The laser light spot will fly out of the target plate if there is a slight twist.
测量盒需要保持静止,靶板面平行于位移表面,激光器光线同时垂直与位移表面和靶板表面。The measurement box needs to remain stationary, the target plate surface is parallel to the displacement surface, and the laser light is perpendicular to the displacement surface and the target plate surface at the same time.
激光器安装在精密位移平台上,能够随着位移台进行三个方向的运动,对于本自动监测系统,只需要进行在垂直于水平面的表面进行运动即可,位移平台位移精密为1μm。当关闭激光器时,监测系统会拍摄一张照片,然后会控制激光器打开,然后测量系统会将两幅图片进行灰度处理,二值化处理,进行相减后再截取最亮点附近区域进行腐蚀处理,直至不能腐蚀。最后剩余亮点的平均坐标即认为是激光器成靶板上的像素坐标。The laser is installed on the precision displacement platform and can move in three directions with the displacement platform. For this automatic monitoring system, it only needs to move on the surface perpendicular to the horizontal plane. The displacement precision of the displacement platform is 1 μm. When the laser is turned off, the monitoring system will take a picture, then control the laser to turn on, and then the measurement system will process the two pictures in grayscale, binarize, subtract and then intercept the area near the brightest point for corrosion processing , until it cannot be corroded. The average coordinates of the remaining bright spots are considered to be the pixel coordinates on the laser target board.
在测量系统的稳定性测试中,保持激光器位置不变,连续做了1000次的测量,得到的结果如图16所示,在图16(a)可以看出激素亮点集中在6个像素点的正方形之内。取这点像素点的平均值为中心,各个测量结果距离这个中心点的像素距离分布概率如图16(b)所示,能够看出像素各个像素点与中心的距离小于3个像素的概率为99.8%,小于4个像素的概率为100%,即可以认为此监测系统的位移测量精度为4个像素点,结合标定结果中相邻两像素间的实际距离,可以得出该自动监测系统的测量精度为4×0.04755435<0.2mm。In the stability test of the measurement system, the position of the laser was kept unchanged, and 1000 consecutive measurements were made. The results obtained are shown in Figure 16. In Figure 16(a), it can be seen that the hormone bright spots are concentrated in 6 pixels. within the square. Taking the average value of this pixel point as the center, the pixel distance distribution probability of each measurement result from this center point is shown in Figure 16(b). It can be seen that the probability that the distance between each pixel point of a pixel and the center is less than 3 pixels is 99.8%, the probability of less than 4 pixels is 100%, that is, it can be considered that the displacement measurement accuracy of this monitoring system is 4 pixels, combined with the actual distance between two adjacent pixels in the calibration result, the automatic monitoring system can be obtained The measurement accuracy is 4×0.04755435<0.2mm.
在实际的测量实验中,控制位移平台进行一个正方形路径移动,每次位移1mm,最终测量结果如图17所示。In the actual measurement experiment, the displacement platform is controlled to move in a square path, each displacement is 1mm, and the final measurement result is shown in Figure 17.
以上实施例仅为说明本发明的技术思想,不能以此限定本发明的保护范围,凡是按照本发明提出的技术思想,在技术方案基础上所做的任何改动,均落入本发明保护范围之内。The above embodiments are only to illustrate the technical ideas of the present invention, and cannot limit the protection scope of the present invention with this. All technical ideas proposed according to the present invention, any changes made on the basis of technical solutions, all fall within the protection scope of the present invention. Inside.
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Cited By (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN111256595A (en) * | 2020-02-18 | 2020-06-09 | 重庆亚派桥梁工程质量检测有限公司 | Photoelectric target type structure displacement measuring method and device and storage medium |
CN112325789A (en) * | 2021-01-04 | 2021-02-05 | 中南大学 | Method for measuring deformation and displacement in model test based on image processing |
WO2021047932A1 (en) | 2019-09-10 | 2021-03-18 | Sms Group Gmbh | Internal welding of pipes and profiles |
CN113390359A (en) * | 2021-06-15 | 2021-09-14 | 董世勇 | High-cutting slope deformation monitoring device |
CN114512039A (en) * | 2022-03-19 | 2022-05-17 | 海宁市职业高级中学 | Paint spraying training system and training method thereof |
CN116045833A (en) * | 2023-01-03 | 2023-05-02 | 中铁十九局集团有限公司 | Bridge construction deformation monitoring system based on big data |
CN116297036A (en) * | 2023-02-17 | 2023-06-23 | 中国地质大学(武汉) | Rock mass freeze-thawing cycle sorting effect simulation test device and method |
CN117419646A (en) * | 2023-12-19 | 2024-01-19 | 南京牧镭激光科技股份有限公司 | Method and system for monitoring displacement of fan spindle based on laser sensor |
CN118980319A (en) * | 2024-01-31 | 2024-11-19 | 浙江霖感智能科技有限公司 | A wireless intelligent laser displacement sensor system and monitoring method |
CN119197736A (en) * | 2024-09-09 | 2024-12-27 | 北京理工大学珠海学院 | A laser transfer amplified structural vibration visual measurement method |
Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN1651855A (en) * | 2005-02-06 | 2005-08-10 | 重庆大学 | Two-dimensional, large-range laser deflection/displacement measurement method and device |
CN1280607C (en) * | 2005-03-23 | 2006-10-18 | 西安交通大学 | Laser dam safety monitoring method |
CN101201240A (en) * | 2006-12-12 | 2008-06-18 | 财团法人工业技术研究院 | Automatic detection method for position of image capturing device and vehicle collision warning system |
JP2009092535A (en) * | 2007-10-10 | 2009-04-30 | Ono Sokki Co Ltd | Optical displacement meter |
CN105444696A (en) * | 2015-12-30 | 2016-03-30 | 天津大学 | Binocular coupling method based on perspective projection linear measurement model, and application of binocular coupling method |
-
2016
- 2016-11-10 CN CN201610987047.0A patent/CN106705857A/en active Pending
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN1651855A (en) * | 2005-02-06 | 2005-08-10 | 重庆大学 | Two-dimensional, large-range laser deflection/displacement measurement method and device |
CN1280607C (en) * | 2005-03-23 | 2006-10-18 | 西安交通大学 | Laser dam safety monitoring method |
CN101201240A (en) * | 2006-12-12 | 2008-06-18 | 财团法人工业技术研究院 | Automatic detection method for position of image capturing device and vehicle collision warning system |
JP2009092535A (en) * | 2007-10-10 | 2009-04-30 | Ono Sokki Co Ltd | Optical displacement meter |
CN105444696A (en) * | 2015-12-30 | 2016-03-30 | 天津大学 | Binocular coupling method based on perspective projection linear measurement model, and application of binocular coupling method |
Non-Patent Citations (2)
Title |
---|
崔红梅: "桥梁挠度快速监测系统", 《中国优秀硕士学位论文全文数据库工程科技II辑》 * |
李颢等: "基于非线性逆透视变换的摄像机畸变参数标定", 《上海交通大学学报》 * |
Cited By (14)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2021047932A1 (en) | 2019-09-10 | 2021-03-18 | Sms Group Gmbh | Internal welding of pipes and profiles |
CN111256595A (en) * | 2020-02-18 | 2020-06-09 | 重庆亚派桥梁工程质量检测有限公司 | Photoelectric target type structure displacement measuring method and device and storage medium |
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Application publication date: 20170524 |