A kind of device based on line laser triangulation irregularly shaped object volume
Technical field
The utility model relates to a kind of measurement mechanism of object volume.Particularly relate to a kind of based on the trigon device based on line laser triangulation irregularly shaped object volume of line laser.
Background technology
The measurement of object volume size all has great significance in a lot of fields such as storage object, transporting objects, object detection, and therefore, the volume of Measurement accuracy object is the work be of practical significance very much, especially to the measurement of irregularly shaped object volume.
Contact and non-contact measurement two kinds are broadly divided into the measurement of irregularly shaped object volume.Wherein, contact type measurement is then very inapplicable to the object of some special substances, such as woodwork, paper products, Ceramic Cultural Relics etc., so namely become a study hotspot to the research of non-contact measurement object volume.
Non-cpntact measurement object volume can adopt non-optical means and optical instrument again, and non-optical measurement means principle is simple, but often device is complicated, and precision is lower; Optical instrument then measuring speed is fast, and precision is high, therefore more by the concern of researcher.
The optical instrument of main flow has digital hologram method, phase measurement, multi-angle image method and laser scanning method etc.Digital hologram method irradiates sample by laser, and generation and the reproducing processes of research hologram realize three-dimensionalreconstruction, and calculate volume, the method speed is fast, resolution is high, but measurement range is subject to equipment parameters affect; Raster pattern is projected to body surface by phase measurement, and depth information is modulated with position mutually to fringe amplitude, thus obtains three-dimensional information and volume, and little, the anti-static noise ability of calculated amount is strong, but speed is slow and can not eliminate the error that high frequency noise causes; Multi-angle image method refers to takes multiple images to testee from different perspectives, then calculates volume by these Images uniting three-dimensional models, requires low, simple to operate for measuring equipment, but measuring accuracy is not high and algorithm complex is higher; Laser scanning method utilizes Laser Scanning Equipment to obtain cloud data, and build the three-dimensional model of testee accordingly, calculate volume, measuring accuracy is relevant to the precision of measuring equipment, but algorithm design is relatively easy, and complexity is lower, and precision is high.
Summary of the invention
Technical problem to be solved in the utility model is, provide a kind of simple to operate, speed is fast, precision high based on the trigon device based on line laser triangulation irregularly shaped object volume of line laser.
The technical scheme that the utility model adopts is: a kind of for the device based on line laser triangulation irregularly shaped object volume, include computing machine, also be provided with the first camera and the second camera for the gathering testee image that are electrically connected with described computing machine respectively, be arranged between described first camera and second camera for providing the laser line generator of laser, and the driving mechanism for driving described testee to rotate, described driving mechanism includes stepper motor, be fixedly installed on the objective table for carrying testee on described stepper motor output shaft top, and the driver element for driving described stepper motor to rotate, described driver element is the control chip by the driver matched with described stepper motor and control and drive system work.
Described laser line generator is centre wavelength is 980nm or 850nm or 808nm or 650nm, light fan angle is greater than the laser line generator that 40 ° are less than 120 °, the first described camera and second camera are respectively arranged with match with described laser line generator for ensureing that light belt extracts integrality and effectively weakens the filter plate that external stray light affects.
The first described camera and second camera to be all field angle the be black and white camera of 35 ° ~ 45 °.
The vertical central plane of the laser light plane of described laser line generator and the first camera and second camera intersects at the center line of objective table, and described laser line generator with the first described camera and second camera distance apart and angulation is field angle according to line laser trigonometry and camera respectively and determines.
A kind of device based on line laser triangulation irregularly shaped object volume of the present utility model, the volume of irregularly shaped object can be measured non-contactly, comprise the object volume of special substance, as woodwork, paper products, Ceramic Cultural Relics etc., any damage can not be caused to testee.Simple to operate, speed is fast, and precision is high.There is following features:
1, principle is simple, and reasonable in design: based on line laser trigonometry, can select device according to the article size that will survey and design apparatus, applicability is strong;
2, measuring accuracy is high: pixel typical resolution is about 0.14mm, demarcates re-projection error and is less than 0.17mm, measures relative error and is not more than 1%;
3, measurement environment strong adaptability, speed is fast: camera installs the optical filter matched with laser center wavelength additional, ensure that light belt extracts integrality and effectively weakens external stray light impact simultaneously, stepper motor and turntable are rigidly connected, and namely complete object dimensional model reconstruction and cubing in 18.2s;
4, system application scalability is strong: system scan produces measured object surface point cloud, and easily extensible is applied to 3-dimensional digital modeling, increases the field such as material manufacture and reverse-engineering.
Accompanying drawing explanation
Fig. 1 is the one-piece construction schematic diagram of the device based on line laser triangulation irregularly shaped object volume of the present invention;
In figure
1: computing machine 2: testee
3: the first cameras 4: second camera
5: laser line generator 6: stepper motor
7: objective table 8: driver element
9: base
Fig. 2 measures mechanical layout schematic diagram when each dimension is no more than 7cm object volume;
Embodiment
Below in conjunction with embodiment and accompanying drawing, a kind of device based on line laser triangulation irregularly shaped object volume of the present utility model is described in detail.
As shown in Figure 1, of the present utility model a kind of for the device based on line laser triangulation irregularly shaped object volume, include computing machine 1, also be provided with the first camera 3 and the second camera 4 for the gathering testee 2 image that are electrically connected with described computing machine 1 respectively, be arranged between described first camera 3 and second camera 4 for providing the laser line generator 5 of laser, and the driving mechanism for driving described testee 2 to rotate, the first described camera 3, second camera 4 and laser line generator 5 are all fixedly installed on a base 9, and, according to line laser trigonometry, the laser light plane of described laser line generator 5 and the vertical central plane of the first camera 3 and second camera 4 intersect at the center line of objective table 7, described laser line generator 5 with the first described camera 3 and second camera 4 distance is apart field angle according to line laser trigonometry and camera respectively and determines.The first described camera 3 and second camera 4 to be all field angle the be black and white camera of 35 ° ~ 45 °.As laser line generator 5 respectively with as described in the first camera 3 and second camera 4 at a distance of 85mm time angle at 45 °.
Described driving mechanism includes stepper motor 6, be fixedly installed on the objective table 7 for carrying testee 2 on described stepper motor 6 output shaft top, and the driver element 8 for driving described stepper motor 6 to rotate, described driver element 8 is the control chips by the driver matched with described stepper motor 6 and control and drive system work.It is the driver of M420B or TB6560 that described stepper motor and driver can select model to be the stepper motor of 42HS4813A4 or 42BYGH47-401A and model, and described control chip can adopt model to be the chip of JM60 or C8051F330 or HC6800.
Described laser line generator 5 is centre wavelength is 980nm or 850nm or 808nm or 650nm, light fan angle is greater than the laser line generator that 40 ° are less than 120 °, the first described camera 3 and second camera 4 are respectively arranged with match with described laser line generator 5 for ensureing that light belt extracts integrality and effectively weakens the filter plate that external stray light affects, be the filter plate of 980nm or 850nm or 808nm or 650nm as selected centre wavelength.The first described camera 3 and second camera 4 can adopt the black and white camera of resolution 640*480 (level × vertical), field angle about 36 ° × 28 ° (vertical × level).
In the present embodiment, by line laser trigonometry, consider the technical parameters such as measurement range, mechanical dimension, image resolution ratio, design for the device based on line laser triangulation irregularly shaped object volume as shown in Figure 2, for the distance H of laser center on vertical direction, the first camera and second camera center and stage surface is 35 ~ 40mm, in horizontal direction, laser is 85mm to the distance L at objective table center and the first camera, second camera center, and the first camera and second camera and laser line generator angle at 45 °.Based on Zhang Zhengyou standardization to whole for demarcating based on the device of line laser triangulation irregularly shaped object volume, obtain the transformation matrix H of image coordinate to world coordinates.