CN104034697B - A kind of assay device manufacturing surface roughness affect laser measurement performance and method - Google Patents

Abstract

The invention discloses a test device and method for manufacturing surface roughness affecting laser measurement performance. The device uses a standard 80m long guide rail to realize large-distance measurement. The laser interferometer positioning system realizes the distance positioning between the laser and the material surface, and the light source is multiple The waveband is adjustable, it can be a monochromatic light source, or a multicolor light source, which can meet the needs of different wave bands and frequency-modulated continuous wave lasers for the study of the influence of surface scattering characteristics. A laser focusing system is placed behind the light source, and the diameter of the laser focusing spot can be adjusted. To meet the needs of research on the influence of laser spot size on scattered light, the dual-axis rotation system and fixture for placing the target adopt an error-proof design, which can improve measurement efficiency and measurement accuracy, and the quarter-arc guide rail design for placing the receiving detector can realize Changes in reflection acceptance angles. The system has a wide range of measurement functions, high measurement accuracy, high efficiency, and can realize long-distance measurement. It is of great significance to the study of the interaction between laser and material surface.

Description

A test device and method for manufacturing surface roughness affecting laser measurement performance

technical field

The invention relates to an optical radiation measurement device, in particular to a test device and method for manufacturing surface roughness affecting laser measurement performance.

Background technique

In practical engineering applications, the surface of the measured target is usually a non-ideal Lambertian surface, that is, the surface has diffuse reflection, and complex multiple reflection phenomena need to be considered. Therefore, it is particularly important to study the scattering characteristics of the target surface. For example: if the spectrum is known The bidirectional reflectance distribution function can be used to deduce the directional spectral absorptivity and directional spectral reflectance. Therefore, the spectral bidirectional reflectance distribution function is an important parameter that reflects the radiation transfer of the material surface, and it is applied in many fields, such as in the field of aerospace remote sensing, industrial measurement In the fields of geological survey, simulation and simulation of targets, the detection of surface material scattering characteristics is required. Accurate measurement of target surface scattering characteristics is an important research basis for many research fields.

In the field of remote sensing detection, the scattering of light by the target can be used to analyze and identify the shape and characteristics of the target; the lidar echo contains a lot of target and background information, and people can extract useful information from the obtained complex information; in the field of industrial measurement , with the growing demand for precision coordinate measurement in large spaces, the realization of non-contact measurement without cooperative targets has become an important research topic. Although the traditional interferometry and the derived laser tracking measurement method have high precision, they are It needs the assistance of cooperative targets such as reflective prisms or cat's eyes, which is often impossible to achieve on site; the continuous laser frequency modulation ranging technology developed in recent years is a new type of laser ranging technology, which can measure without cooperative targets, with a large measurement range and high accuracy. It has significant advantages, but the method is still immature, and some key bottlenecks have not been resolved. One of the key issues is the impact of the surface on the laser measurement performance after the laser is directly incident on the manufactured surface to be tested. In the case of a cooperative target, since the surface characteristics of the target are certain and known, the received echo signal is also stable and predictable, which is also an important reason for the high accuracy of the ranging system with a cooperative target; For the ranging system of the cooperative target, the target surface irradiated by the laser light is unknown and varies widely. The roughness, color, and texture of the measured manufacturing surface will affect the intensity, phase, polarization state and other information of the received laser light. Angle, laser focus spot size will also affect the received scatter signal.

Although some physical models have been developed in the physics community to describe the scattering characteristics of rough targets, they are all modeled on the premise of simplifying the problem and idealizing the target. In practical applications, the calculation based on the ideal model will inevitably Errors are generated, which cannot meet the high-precision requirements, but the real scattering characteristics of the rough surface can reflect the unique characteristics other than the geometric characteristics of the surface. The scattering information generated by each surface is uniquely determined. The interaction effect of surfaces has important guiding significance for the optimization of measurement equipment and the improvement of measurement accuracy, and is also the research basis of many research fields.

The function of the traditional scattering measurement device is relatively single, which cannot meet the needs of multi-faceted measurement of the interaction between the laser and the surface. For example, the existing bidirectional reflectance distribution function measurement device can only measure the scattering characteristics of the surface at a short distance. The energy attenuation in the air and the influence of the diameter of the focused spot on scattering cannot be measured. Other existing surface scattering measurement devices also generally have defects such as single function, short measurement distance, low positioning accuracy, and large measurement error.

Contents of the invention

The present invention provides a test device and method for manufacturing surface roughness that affects laser measurement performance. The present invention realizes the measurement of scattering characteristics of remote surfaces and improves the measurement accuracy and measurement cycle. See the following description for details:

A test device for manufacturing surface roughness that affects laser measurement performance, the test device includes: standard long guide rail, light source, laser focusing system, object loading platform, horizontal rotary table, vertical rotary table, sample fixture, connecting rod, quarter point One arc sliding guide rail, receiving detector, laser interferometer transmitting end, laser interferometer receiving end and PC,

The light source, the laser focusing system and the emitting end of the laser interferometer are fixed on one end of the standard long guide rail, and the horizontal rotating table and the vertical rotating table form a two-axis rotating system, and the receiving detector And the receiving end of the laser interferometer is fixed on the loading platform controlled by the laser interferometer, and moves freely on the standard long guide rail, and the sample holder is installed on the axis of the vertical rotating table, and The quarter-arc sliding guide rail of the receiving detector is installed on the vertical rotary table through the connecting rod, and rotates with the rotation of the vertical rotary table, the horizontal rotary table, the vertical rotary table The displacement of the rotary table, the object-carrying platform, and the movement of the receiving detector on the quarter-arc sliding guide rail are all uniformly controlled by the PC.

The light source is a multi-band adjustable light source, including: a visible light source of 400nm-800nm, a near-infrared light source of 800nm-2500nm and an infrared light source of 2500nm-5000nm.

The turbines of the horizontal rotary table and the vertical rotary table are fine-pitch turbines, and the vernier resolution on the horizontal rotary table and the vertical rotary table is 5 arc minutes.

A test method for manufacturing surface roughness affecting laser measurement performance, said method comprising the following steps:

1) Place the sample in the sample holder so that the surface of the sample fits the end face of the sample holder;

2) Set the incident angle of the light source, the size of the incident spot, the distance between the light source and the surface of the sample to be measured, and the moving distance;

3) Keep the incident angle set above, measure the scattered light energy of the surface space at the position to be measured, change the receiving azimuth angle by rotating the vertical rotating table within a range of 360°, and slide the receiving detector in a quarter arc Move on the guide rail to receive light energy with different reflection angles;

4) After measuring the light energy of the position to be measured above, keep the incident angle of the light source unchanged, move to the next position according to the moving distance set in step 2), and measure the light energy of this position according to step 3) , and then move to the next set position, repeat steps 3) and 4) until the light energy of all set distances is measured;

After the above measurement is completed, the incident angle of the light source is changed, and steps 3) and 4) are repeated to complete the measurement at different incident angles.

The beneficial effects of the technical solution provided by the present invention are: the system uses a standard 80m long guide rail to realize large-distance measurement, uses a laser interferometer positioning system to realize the distance positioning between the laser and the material surface, and the light source is multi-band adjustable and can be monochromatic The light source can also be a multi-color light source, which can meet the needs of research on the influence of different wave bands and frequency-modulated continuous wave lasers on surface scattering characteristics. The emitted light source passes through the laser focusing system, and the diameter of the laser focusing spot can be adjusted by adjusting the laser focusing system. To meet the needs of research on the influence of the diameter of the laser spot on scattered light, the dual-axis rotation system and the sample fixture for placing the surface to be measured adopt an error-proof design, which can improve measurement efficiency and accuracy, and place a quarter of the arc of the receiving detector The guide rail design can realize the measurement of surface space scattered light. The invention has high measurement accuracy and high efficiency, can realize large-distance measurement, has many measurement functions, can complete the measurement of the hemispherical space light scattering of the surface to be measured and the measurement of the influence of the size of the laser focus spot on the surface scattering, and the energy of the incident light after long-distance transmission The attenuation can also be measured by the device, and the invention can be widely used in the fields of material properties and target simulation, remote sensing detection, geological survey, industrial large-scale non-cooperative target measurement and other fields that need to study the interaction between laser and surface.

Description of drawings

Fig. 1 is the schematic structural diagram of the test device for manufacturing surface roughness affecting laser measurement performance;

Figure 2 is a block diagram of a test setup where surface roughness affects laser measurement performance;

Figure 3 is a design drawing of the sample fixture;

Fig. 4 is a schematic diagram of the measurement process;

Figure 5 shows the energy distribution of the scattered light in the roughness sample block space

Figure 6 shows the energy distribution of scattered light in the roughness sample block space

In the accompanying drawings, the list of parts represented by each label is as follows:

1-80m standard long guide rail, 2-light source, 3-laser focusing system, 4-loading platform, 5-horizontal rotation stage, 6-vertical rotation stage, 7-sample fixture, 8-connecting rod, 9-quarter An arc sliding guide rail, 10-receiving detector, 11-laser interferometer transmitting end, 12-laser interferometer receiving end, 13-PC machine; A-transmitting module, B-loading platform module, C-receiving module and D-Electrical control module.

detailed description

In order to make the purpose, technical solution and advantages of the present invention clearer, the implementation manners of the present invention will be further described in detail below.

Referring to Fig. 1 and Fig. 2, the test device for manufacturing surface roughness affecting laser measurement performance includes: standard long guide rail 1, light source 2, laser focusing system 3, object loading platform 4, horizontal rotary table 5, vertical rotary table 6, sample Fixture 7, connecting rod 8, quarter arc sliding guide rail 9, receiving detector 10, laser interferometer transmitting end 11, laser interferometer receiving end 12,

The light source 2, the laser focusing system 3 and the laser interferometer transmitting end 11 are fixed on one end of the standard long guide rail 1, and the horizontal rotating table 5 and the vertical rotating table 6 form a two-axis rotating system, a receiving detector 10 and a laser interferometer receiving end 12 Fixed on the loading platform 4 controlled by the laser interferometer, it can move freely on the standard long guide rail 1, the sample holder 7 is installed on the axis of the vertical rotary table 6, and the quarter arc of the receiving detector 10 is installed The sliding guide rail 9 is installed on the vertical rotating table 6 through the connecting rod 8, and rotates with the rotation of the vertical rotating table 6. The movement on an arc sliding guide rail 9 is all controlled by PC 13 in a unified manner.

Wherein, the standard long guide rail 1 is 80m long, and the loading platform 4 can move freely on the standard long guide rail 1, and is precisely positioned by a laser interferometer.

In the embodiment of the present invention, by fixing the transmitting end 11 of the laser interferometer on one end of the standard long guide rail 1, and fixing the receiving end 12 of the laser interferometer on the loading platform 4, the laser interferometer can be used to realize the alignment of the loading platform 4 in the standard Precise mobile positioning on long rails1.

Referring to Figure 2, the whole is composed of four modules: transmitting module A, loading platform module B, receiving module C and electronic control module D. The launch module 1 is composed of a light source 2 and a laser focusing system 3; the loading platform module B is composed of a loading platform 4, a standard long guide rail 1 and a two-axis rotation system (composed of a horizontal rotation table 5 and a vertical rotation table 6), and the loading platform 4 As a mobile platform, the two-axis rotation system that realizes the space pose of the surface to be measured is fixed on the loading platform 4, and is positioned by a laser interferometer; the receiving module C is composed of a receiving detector 10 and a quarter-arc sliding guide rail 9 Combining with the dual-axis rotation system to complete the measurement of the energy of spatial light scattering, the electronic control module D that realizes the automatic operation of the entire measurement system is uniformly controlled by the PC 13.

In specific implementation, the light source 2 is a multi-band adjustable light source, including: visible light source 400nm-800nm, near-infrared light source 800nm-2500nm and infrared light source 2500nm-5000nm. In addition, light source 2 can also be a frequency-modulated continuous wave light source, which can meet Research measurements of the effects of polychromatic light interacting with surfaces are required. The laser focusing system 3 can effectively control and select the diameter of the outgoing laser spot, which is adjusted by the pinhole diaphragm.

Wherein, referring to FIG. 3 , the sample holder 7 is installed on the axis of the vertical rotary table 6 , and the end face of the sample holder 7 coincides with the vertical axis of the horizontal rotary table 5 to realize any transformation of the sample space pose. The turbines of the horizontal rotary table 5 and the vertical rotary table 6 are fine-pitch turbines, and the worm is controlled by a DC servo motor to drive the turbines to rotate within 360°. The worm is connected to the reducer shaft fixed on the motor. The horizontal rotary table 5 and the vertical The resolution of the vernier scale on the rotary stage 6 is 5 arc minutes.

Referring to Fig. 3, further, the sample fixture 7 adopts an error-proof design, that is, the sample slot has a certain width, which can be adapted to samples of different thicknesses. When measuring, only the surface of the sample needs to be attached to the end surface of the fixture, and no other position adjustment is required. No matter how the shaft system is rotated, the light source 2 is always incident on the center of the sample, saving the overall measurement time.

Wherein, the receiving detector 10 is installed on the quarter-arc sliding guide rail 9, and the receiving detector 10 can be replaced according to the measurement requirements, for example, it can be a photoelectric detector, an optical power detector or a brightness detector.

Quarter-arc sliding guide rail 9 adopts a standard arc design, and the center of the circle coincides with the intersection of the two axes of the dual-axis rotation system. The guide rail surface is a turbine gear tooth, and the turbine gear is driven by an electric worm to rotate, thereby realizing receiving and detecting The detector 10 moves on the quarter-arc sliding guide rail 9 to receive light energy of different reflection angles, and the receiving detector 10 has a movement range of 0° to 90° on the quarter-arc guide rail 9 .

Connecting rod 8 and quarter arc guide rail 9 link to each other with vertical rotary table 6, are fixed on vertical rotary table 6, rotate with the rotation of vertical rotary table 6, thereby change receiving azimuth angle, the length of connecting rod 8 and four The one-third arc guide rail 9 can be designed in different sizes according to the measurement requirements, and only needs to be fixed on the vertical rotating table 6 to get final product.

The test method that the surface roughness of the present invention affects the laser measurement performance comprises the following steps:

1) The sample is placed in the sample holder 7, so that the surface of the sample is attached to the end face of the sample holder 7;

2) Set the incident angle of the light source 2, the size of the incident spot, the distance between the light source 2 and the surface of the sample to be tested, and the moving distance;

3) Keep the above-mentioned incident angle, measure the surface space scattered light energy at the position to be measured, change the receiving azimuth angle by the rotation of the vertical rotating table 6 in the range of 360 °, and use the receiving detector 10 in a quarter circle Move on the arc sliding guide rail 9 to receive light energy of different reflection angles;

4) After measuring the light energy of the position to be measured above, keep the incident angle of light source 2 unchanged, move to the next position according to the moving distance set in step 2, measure the light energy of this position according to step 3, and then move Go to the next set position and repeat steps 3) and 4) until the light energy of all set distances is measured;

After the above measurement is completed, change the incident angle of the light source 2, which can minimize the radial runout error introduced by the rotation of the horizontal rotary table 5, thereby reducing the measurement error, and repeat steps 3) and 4) to complete different incident angles. Angle time measurement.

If the spot size needs to be changed, adjust the laser focusing system 3 so that spots of different diameters are incident on the surface to be measured, and the rotation of the two-axis rotation system and the movement of the receiving detector 10 on the quarter-arc sliding guide rail 9 Move to complete the measurement of spatially scattered light energy.

The specific measurement method will be described in detail below in conjunction with the schematic diagram 4 of the measurement process. Here, the variable-distance space scattered light energy measurement scheme with the largest amount of data collection is taken as an example. Other measurement functions can be realized by extracting some steps of this measurement scheme.

1) First, turn on the light source 2 to preheat for 20 minutes, install the sample to be tested in the sample holder 7 as required, so that the surface of the sample and the end surface of the sample holder 7 are closely attached.

2) Set the incident angle of the laser and the size of the focused spot. The PC 13 controls the rotation of the horizontal rotary table 5 to change the incident angle of the laser. In this embodiment, the initial incident angle is set to 0°, and the distance between the light source 2 and the surface of the sample to be measured is Set to 5m, the laser interferometer positioning system drives the object-carrying platform 4 to move to the designated position.

3) Start the measurement, and receive the light energy of different reflection angles by the movement of the receiving detector 10 on the quarter-arc sliding guide rail 9. After the measurement, the rotation of the vertical rotary table 6 is controlled by the PC 13 to change the receiving angle. The azimuth angle is set to 5° in this embodiment, and the light energy of different reflection angles under this azimuth angle is received by the movement of the receiving detector 10 on the quarter-arc sliding guide rail 9 .

4) Step 3) is repeated until the vertical rotating table 6 rotates through 360°, that is, the scattered light energy in the hemispherical space is measured.

5) After completing step 4), the next measurement position is set by the control software of the host computer of the laser interferometer, which is 10m in this embodiment.

6) Repeat steps 3), 4), and 5) until the distance to be measured is measured. Change the incident angle of the light source, and set the angle step by the upper computer control software in the horizontal rotating table 5 to 5°.

7) Repeat steps 2), 3), 4), 5), and 6) until the hemispherical space scattered light energy on the surface is measured at different incident angles and different distances.

In the above measurement, when changing the incident distance, keep the incident angle of the light source 2 constant, as shown in Figure 4, this can minimize the radial runout error introduced by the rotation of the horizontal rotating table 5, thereby reducing the measurement error . If it is necessary to change the size of the spot, adjust the laser focusing system 3 so that spots of different diameters are incident on the surface to be measured, and select steps 2), 3), and 4) to complete the measurement. Fig. 5 and Fig. 6 are the measurement results of the scattered light energy distribution in the roughness sample block space. The roughness of the sample block in the figure is 0.8μm, the processing method is a planer, and the measurement results are the collected data in the hemispherical space. Since the coordinates of each collection point are space spherical coordinates about the zenith angle and azimuth angle, they need to be converted into flute Carr coordinates for surface fitting. Figure 5 shows the angle of incidence θ _i = 30°, the azimuth of incidence When the measurement results, Figure 6 shows the incident angle θ _i =30°, the incident azimuth angle It can be seen from the figure that when the incident angle is the same, but the incident azimuth angle is different, different scattered light energy distributions will be obtained, and the scattered light peak position and energy distribution shape will change.

In the embodiments of the present invention, unless otherwise specified, the models of the devices are not limited, as long as they can complete the above functions.

Those skilled in the art can understand that the accompanying drawing is only a schematic diagram of a preferred embodiment, and the serial numbers of the above-mentioned embodiments of the present invention are for description only, and do not represent the advantages and disadvantages of the embodiments.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the protection of the present invention. within range.

Claims (3)

1. A test device for manufacturing surface roughness that affects laser measurement performance, characterized in that, the test device includes: standard long guide rail, light source, laser focusing system, loading platform, horizontal rotary table, vertical rotary table, sample fixture , connecting rod, quarter-arc sliding guide rail, receiving detector, laser interferometer transmitting end, laser interferometer receiving end and PC, The light source, the laser focusing system and the emitting end of the laser interferometer are fixed on one end of the standard long guide rail, and the horizontal rotating table and the vertical rotating table form a two-axis rotating system, and the receiving detector And the receiving end of the laser interferometer is fixed on the loading platform controlled by the laser interferometer, and moves freely on the standard long guide rail, and the sample holder is installed on the axis of the vertical rotating table, and The quarter-arc sliding guide rail of the receiving detector is installed on the vertical rotary table through the connecting rod, and rotates with the rotation of the vertical rotary table, the horizontal rotary table, the vertical rotary table The displacement of the rotary table, the object-carrying platform, and the movement of the receiving detector on the quarter-arc sliding guide rail are all uniformly controlled by the PC. 2. A test device for manufacturing surface roughness affecting laser measurement performance according to claim 1, wherein the light source is a multi-band adjustable light source, including: visible light source 400nm-800nm, near-infrared light source 800nm ～2500nm and infrared light source 2500nm～5000nm. 3. A test method for making surface roughness influences laser measurement performance, is characterized in that, described method comprises the following steps: 1) Place the sample in the sample holder so that the surface of the sample fits the end face of the sample holder; 2) Set the incident angle of the light source, the size of the incident spot, the distance between the light source and the surface of the sample to be measured, and the moving distance; 3) Keep the incident angle set above, measure the scattered light energy of the surface space at the position to be measured, change the receiving azimuth angle by rotating the vertical rotating table within a range of 360°, and slide the receiving detector in a quarter arc Move on the guide rail to receive light energy with different reflection angles; 4) After measuring the light energy of the position to be measured above, keep the incident angle of the light source unchanged, move to the next position according to the moving distance set in step 2), and measure the light energy of this position according to step 3) , and then move to the next set position, repeat steps 3) and 4) until the light energy of all set distances is measured; After the above measurement is completed, the incident angle of the light source is changed, and steps 3) and 4) are repeated to complete the measurement at different incident angles.