Optical detection device and detection method for high-precision gears

Abstract

The application discloses an optical detection device and method for high-precision gears, and belongs to the technical field of optical detection. The device comprises a detection main body, a rotating workbench, a driving motor, a transmission box body, a guide rail support, a hydraulic cylinder, a driving track, a bearing frame, a visual detection camera fixed to the bearing frame, a lens and a light source assembly, and a probe detection head. The controller executes the detection steps: obtaining a tooth profile light intensity modulation characteristic factor based on tooth profile image grayscale data; obtaining an eccentric coupling characteristic vector of tooth profile inclination angle by combining the tooth tip circle diameter data and the tooth surface light spot offset data; then fusing the tooth surface reflectivity data and the tooth profile angle data detected by the probe to obtain a tooth profile multi-dimensional compensation correction factor; and adjusting the imaging parameters according to the compensation correction factor to realize adaptive closed-loop control. Through multi-dimensional feature fusion and feedback iteration optimization, the application effectively decouples the tooth surface roughness and imaging interference, compensates the inclination angle and eccentric coupling distortion, and improves the detection precision and repeatability.

Description

Technical Field

[0001] This invention relates to the field of optical inspection technology, and in particular to an optical inspection device and method for high-precision gears. Background Technology

[0002] As a core component of mechanical transmission systems, the machining accuracy of gears directly affects the noise, vibration, lifespan, and efficiency of the transmission system. The inspection of high-precision gears typically requires simultaneous measurement of tooth thickness, tooth height (length measurement), pressure angle, pitch angle (angle measurement), tooth surface defect area (area measurement), as well as tooth profile deviation and tooth direction deviation (irregular surface or contour measurement).

[0003] Existing optical inspection devices for high-precision gears typically consist of an image acquisition unit, a rotating bearing platform, and an image processing system. Their basic working principle is as follows: a vision camera acquires images of the tooth profile, an edge extraction algorithm obtains the tooth profile boundaries, and then geometric parameters such as tooth thickness and pressure angle are calculated based on the boundary points. However, such devices suffer from the following problems and shortcomings in practical applications: First, tooth surface roughness causes speckle effects in reflected light, leading to random shifts in edge extraction results. Existing technologies employ filtering algorithms to suppress speckle noise, but these methods face an inherent contradiction between noise suppression and edge preservation, and the parameters are difficult to adjust adaptively. Second, the tooth surface tilt angle causes a shift in the reflected light path, resulting in perspective distortion in the tooth profile images acquired by the camera. Clamping eccentricity causes the actual radial position of each tooth to fluctuate sinusoidally, deviating the tooth profile position in the image from its theoretical position. These two effects coexist and are coupled within the same inspection process. Existing technologies typically treat tilt angle and eccentricity as independent error sources, calibrating and compensating them separately, neglecting the coupling relationship between the two. This makes it difficult to compensate in real time during the inspection process. Furthermore, the tooth profile data obtained by optical inspection and the tooth angle data obtained by contact inspection each reflect different sides of the tooth surface. Existing technologies usually use optical inspection data and contact inspection data independently, which prevents the establishment of a correlation model between the two. Consequently, it is difficult to utilize the optical property independence of contact data to verify and assist the optical inspection results. Summary of the Invention

[0004] The technical problem to be solved by the present invention is that the existing technology has the following shortcomings: the mutual interference between tooth surface roughness and optical imaging is not effectively decoupled, the coupling effect between tooth surface inclination angle and clamping eccentricity is not fully considered, and the fusion and utilization of optical detection data and contact detection data is insufficient. To this end, we propose an optical detection device and detection method for high-precision gears.

[0005] In a first aspect, one embodiment of the present invention provides an optical inspection device for high-precision gears, comprising: an inspection body, wherein a rotary table, a drive motor and a transmission housing are disposed on the inspection body, the drive motor is connected to the transmission housing and the rotary table in a transmission relationship, a first guide rail bracket and an auxiliary track frame are fixedly mounted on the surface of the inspection body located in the inspection area, a first drive track and a first hydraulic cylinder are fixedly mounted on the first guide rail bracket, the piston rod of the first hydraulic cylinder is connected to the slide of the first drive track in a transmission relationship, a second track bracket is slidably mounted on the first drive track and the auxiliary track frame, a second hydraulic cylinder and a second drive track are fixedly mounted on the surface of the second track bracket, the piston rod of the second hydraulic cylinder is connected to the slide of the second drive track in a transmission relationship, a support frame is slidably mounted on the second track bracket along the second drive track, and a visual inspection camera, a lens and a light source assembly and a probe inspection head are fixedly mounted on the support frame; The visual inspection camera, the lens and light source assembly, and the probe inspection head cooperate to perform optical inspection of gears. The inspection device also includes a controller configured to perform the following steps of optical gear inspection: Based on the grayscale data of the tooth profile image acquired by the visual inspection camera, a tooth profile intensity modulation feature factor is obtained; based on the tooth profile intensity modulation feature factor, the tooth tip circle diameter data and tooth surface spot offset data acquired by the visual inspection camera, an eccentric coupling feature vector of the tooth profile tilt angle is obtained; based on the eccentric coupling feature vector, the tooth surface reflectivity data acquired by the lens and light source assembly and the tooth profile angle data acquired by the probe detection head, a tooth profile multi-dimensional compensation correction factor is obtained; and the imaging parameters are adjusted based on the tooth profile multi-dimensional compensation correction factor.

[0006] Preferably, four positioning fixtures are fixedly installed on the upper surface of the rotary table in the detection area; The detection body is also fixedly equipped with a display screen and a three-color warning light. The display screen is located above the detection area of ​​the detection body, and the three-color warning light is located on the top of the detection body. The display screen is used to display the detection results, and the three-color warning light is used to indicate the operating status of the equipment.

[0007] Secondly, embodiments of the present invention also provide an optical inspection method for high-precision gears, comprising: The visual inspection camera is used to collect the pixel grayscale values ​​of each tooth position and each cross section of the gear, and based on the ratio of the tooth surface grayscale variance to the average grayscale value of the pixel grayscale value, the ratio of the cross section normal sampling length to the light transmission area of ​​the lens and light source assembly, and the reference light intensity modulation factor, the tooth profile light intensity modulation feature factor is obtained. Based on the ratio calculation of the tooth profile light intensity modulation characteristic factor in the tooth tip section, pitch circle section and tooth root section, combined with the ratio of the reference tooth tip circle diameter to the measured average tooth tip circle diameter and the ratio of the lateral offset of the light spot centroid to the offset of the reference light spot, the eccentric coupling characteristic vector of the tooth profile inclination angle is obtained. Based on the weighted fusion of the eccentric coupling feature vector and the tooth profile light intensity modulation feature factor, and combined with the fusion result of the mean tooth surface reflectivity and the tooth profile angle statistical parameters, a multi-dimensional compensation correction factor for the tooth profile is obtained. The tooth profile multidimensional compensation correction factor is compared with a preset convergence range until the tooth profile multidimensional compensation correction factor converges to the convergence range.

[0008] Preferably, the process of obtaining the tooth profile light intensity modulation feature factor includes: The pixel grayscale values ​​collected by the visual inspection camera at each tooth position and each cross section of the gear are obtained to obtain the grayscale variance and average grayscale of the tooth surface. Obtain the cross-sectional normal sampling length along the tooth profile normal direction and the light-transmitting area of ​​the lens and light source assembly; Multiply the ratio of the tooth surface grayscale variance to the tooth surface average grayscale by the ratio of the cross-sectional normal sampling length to the light-transmitting area, and then divide by the reference light intensity modulation factor to obtain the tooth profile light intensity modulation feature factor. The reference light intensity modulation factor is obtained by the standard gear in the same way during the calibration phase.

[0009] Preferably, the process of obtaining the eccentric coupling feature vector includes: Obtain the profile light intensity modulation characteristic factors of the tooth tip section, pitch circle section and tooth root section of all tooth positions, and record the profile light intensity modulation characteristic factor of the tooth tip section as the tooth tip section light intensity modulation factor, the profile light intensity modulation characteristic factor of the tooth root section as the tooth root section light intensity modulation factor, and the profile light intensity modulation characteristic factor of the pitch circle section as the pitch circle section light intensity modulation factor. The product of the light intensity control factor of the tooth tip section and the light intensity control factor of the tooth root section is divided by the square of the light intensity control factor of the pitch circle section to obtain the tooth profile section inclination effect ratio. Obtain a reference tooth tip circle diameter and a measured average tooth tip circle diameter acquired by the visual inspection camera, and use the ratio of the reference tooth tip circle diameter to the measured average tooth tip circle diameter as a tooth position radial deviation scaling factor. The lateral offset of the centroid of the light spot reflected from the tooth surface and the offset of the reference light spot are obtained from the visual inspection camera. The ratio of the lateral offset of the centroid of the light spot to the offset of the reference light spot is used as the normalization index of the reflected light path offset. Multiply the tooth profile section inclination effect ratio, the tooth position radial deviation proportional factor, and the reflected light path offset normalization index, and then divide by the reference normalization factor to obtain the eccentric coupling characteristic vector of the tooth profile inclination angle. The reference normalization factor is obtained by the standard gear in the same way as the tooth profile section inclination effect ratio during the calibration phase.

[0010] Preferably, the process of obtaining the multi-dimensional compensation correction factor for the tooth profile includes: The sum of the products of the eccentric coupling feature vector of the tooth profile inclination angle of all tooth positions and the light intensity control factor of the corresponding pitch circle section is obtained, and divided by the product of the number of teeth and the normalized reference light intensity control factor, to obtain the average coupling distortion ratio of the entire tooth circumference. The average reflectance of the tooth surface is obtained by calculating the reflected light intensity received by the visual inspection camera after the lens and light source assembly illuminate the tooth surface with a fixed incident light intensity. The standard deviation and minimum tooth profile angle of the tooth profile obtained by the probe detection head touching the tooth surface are obtained. The average reflectance of the tooth surface is divided by the ratio of the sum of the standard deviation of the tooth profile angle and the minimum tooth profile angle to the reference pressure angle to obtain the matching trade-off coefficient. The tooth profile multidimensional compensation correction factor is obtained by multiplying the average coupling distortion ratio of the entire tooth circumference with the matching trade-off coefficient.

[0011] Preferably, the process of comparing the multi-dimensional tooth profile compensation correction factor with a preset convergence range includes: If the tooth profile multi-dimensional compensation correction factor exceeds the convergence range, a feedback control command is generated based on the value of the tooth profile multi-dimensional compensation correction factor to adjust the light transmission area, focus position, or illumination intensity of the lens and light source assembly, and the process of acquiring the tooth profile light intensity modulation feature factor is returned to re-acquire the image and recalculate until the tooth profile multi-dimensional compensation correction factor converges to the convergence range.

[0012] Preferably, during the feedback control process, when the tooth profile multi-dimensional compensation correction factor is greater than the upper limit of the convergence range, the light-transmitting area is reduced and the focusing position is adjusted to increase the depth of field and compensate for the image plane shift caused by the tooth surface tilt angle. When the tooth profile multidimensional compensation correction factor is less than the lower limit of the convergence range, the illumination intensity and exposure time are increased to improve the signal-to-noise ratio, and the illumination angle is adjusted to optimize the reflected light path.

[0013] Preferably, after the multi-dimensional compensation correction factor of the tooth profile converges to the convergence range, under optimal imaging conditions, the parameters of the gear's length, angle, area, and irregular surface or contour in four dimensions are remeasured by the visual inspection camera and the probe inspection head, and the inspection results are displayed on the display screen, and the status signal is output by the three-color warning light.

[0014] The technical effects and advantages of this invention are as follows: In this invention, the ratio of the variance of the tooth surface grayscale to the average grayscale of the tooth surface is calculated to obtain the degree of grayscale fluctuation per unit average brightness. This ratio is proportionally scaled to both the variance and the mean as the illumination intensity changes, keeping the ratio stable and eliminating the interference of illumination fluctuations on the tooth surface roughness characterization. Furthermore, the ratio of the cross-sectional normal sampling length to the light-transmitting area is introduced as a normalization coefficient, unifying the sampling geometry and imaging optical conditions into the feature expression. This feature is not a simple grayscale statistical value, but a deep parameter characterizing the micro-morphology of the tooth surface within the context of the optical imaging link, carrying complete information on how tooth surface roughness affects optical imaging quality. Based on this, the detection device can automatically sense the differences in tooth surface optical characteristics at each cross-section of each tooth position.

[0015] In this invention, the ratio calculation between the tooth profile light intensity modulation feature factors corresponding to the tooth tip section, pitch circle section, and tooth root section is used to offset the combined influence of the absolute level of tooth surface roughness, retaining only the information of the tilt angle difference. Simultaneously, the ratio of the reference tooth tip circle diameter to the measured average tooth tip circle diameter for each tooth position is used as the tooth position radial deviation ratio factor, and the ratio of the reflected light spot centroid offset to the reference offset is used as the optical path offset normalization index. The feature parameters of the above three dimensions (tilt angle effect, eccentricity effect, and optical path offset effect) are multiplied and fused together with the benchmark normalization factor obtained during the calibration stage to obtain the eccentric coupling feature vector element. This feature integrates three mutually coupled geometric distortion effects into a comprehensive index. Based on this, the detection device can identify the degree of coupling distortion and its full circumferential distribution pattern of each tooth position in real time during the detection process, automatically sensing changes in the clamping state without stopping the machine for offline eccentric calibration.

[0016] In this invention, the eccentric coupling feature vectors of all tooth positions are weighted, summed, and normalized by the mean after taking the mean of the pitch circle section light intensity modulation factor to obtain the average coupling distortion ratio of the entire tooth circumference, reflecting the overall influence of geometric distortion factors on imaging. Simultaneously, the mean tooth surface reflectivity is compared with the tooth profile angle statistical parameter (the sum of the standard deviation and the minimum value divided by the reference pressure angle) to obtain a matching trade-off coefficient, reflecting the degree of matching between the optical and geometric characteristics of the tooth surface. Multiplying the feature parameters of these two complementary dimensions yields a multi-dimensional tooth profile compensation correction factor. This feature integrates four dimensions of information: tooth surface optical characteristics, geometric coupling distortion, tooth surface reflectivity, and tooth profile geometric consistency, forming a comprehensive global imaging quality evaluation index. Based on this, the detection device can automatically determine the quality of the current detection conditions according to the numerical range of the multi-dimensional tooth profile compensation correction factor and generate feedback control commands to adjust imaging parameters such as lens aperture, focus position, and illumination intensity until the detection conditions converge to the optimal state. This adaptive optimization mechanism enables the device to automatically adapt to the detection requirements of different tooth surface roughness, different clamping eccentricity, and different lighting conditions, always working under the best imaging conditions, which significantly improves the accuracy and repeatability of the detection results. Attached Figure Description

[0017] Figure 1 This is a front view of the optical inspection device for high-precision gears according to the present invention; Figure 2 This is a top cross-sectional view of the optical inspection device for high-precision gears according to the present invention; Figure 3 This is a partial structural cross-sectional view of the optical inspection device for high-precision gears according to the present invention; Figure 4 For the present invention Figure 3 Enlarged schematic diagram of the structure at point A; Figure 5 This is a schematic diagram showing the distribution of the detection area in the optical inspection of high-precision gears according to the present invention. Figure 6 This is a schematic flowchart of the high-precision gear optical inspection method of the present invention.

[0018] In the diagram: 1-Detection body, 2-Display screen, 3-Tricolor warning light, 4-Drive motor, 5-Transmission box, 6-Rotating worktable, 7-Positioning fixture, 8-First guide rail bracket, 9-First hydraulic cylinder, 10-First drive rail, 11-Auxiliary rail frame, 12-Second rail bracket, 13-Second hydraulic cylinder, 14-Second drive rail, 15-Bearing frame, 16-Visual inspection camera, 17-Lens and light source assembly, 18-Probe detection head. Detailed Implementation

[0019] The present invention will now be described in further detail with reference to the accompanying drawings and preferred embodiments.

[0020] Please refer to Figures 1 to 6 The present invention provides an optical inspection device for high-precision gears.

[0021] In one exemplary embodiment, the device includes a detection body 1, which serves as the supporting foundation for the entire device. Its upper surface is divided into a detection area and an operation area. A rotary table 6 is disposed within the detection area, and the rotary table 6 is driven by a drive motor 4 via a transmission housing 5. The drive motor 4 is preferably a servo motor, which is connected to a worm gear or precision gear transmission mechanism within the transmission housing 5 to transmit power to the rotary table 6 and ensure that the rotary table 6 can perform high-precision indexing rotation according to a preset angular step size. This transmission connection ensures the positioning accuracy of the gear during circumferential detection.

[0022] Four positioning clamps 7 are fixedly installed on the upper surface of the rotary table 6 in the detection area. The positioning clamps 7 are preferably radially evenly distributed claws or elastic clamping mechanisms, used to clamp the hub or end face of the gear to be tested in the radial direction, ensuring that the gear axis is coaxial with the rotation axis of the rotary table 6.

[0023] The surface of the detection body 1 located in the detection area is also fixedly equipped with a first guide rail bracket 8 and an auxiliary rail frame 11. A first drive rail 10 and a first hydraulic cylinder 9 are fixedly mounted on the first guide rail bracket 8. The piston rod of the first hydraulic cylinder 9 is connected to the slide of the first drive rail 10. A second rail bracket 12 is slidably mounted on the first drive rail 10 and the auxiliary rail frame 11. Specifically, one end of the second rail bracket 12 is fixedly connected to the slide of the first drive rail 10, and its other end is slidably engaged with the auxiliary rail frame 11 via a slider to achieve cross-rail support and ensure smooth movement.

[0024] A second hydraulic cylinder 13 and a second drive rail 14 are fixedly mounted on the surface of the second track support 12. The piston rod of the second hydraulic cylinder 13 is connected to the slide of the second drive rail 14. A support frame 15 is slidably mounted on the second track support 12 along the second drive rail 14. That is, the support frame 15 can move up and down along the second drive rail 14 under the drive of the second hydraulic cylinder 13.

[0025] A visual inspection camera 16, a lens and light source assembly 17, and a probe inspection head 18 are fixedly mounted on the support frame 15. The lens and light source assembly 17 includes a telecentric lens or a fixed-focus lens, a coaxial light source or a ring light source, used to provide stable and uniform illumination conditions for visual inspection. The probe inspection head 18 is preferably a high-precision contact-triggered probe or a scanning probe.

[0026] Understandably, through the coordinated action of the first hydraulic cylinder 9 and the second hydraulic cylinder 13, the support frame 15 has controllable degrees of freedom in both the horizontal (X-axis) and vertical (Z-axis) directions. Combined with the rotational motion (C-axis) of the rotary table 6, the visual inspection camera 16 and the probe inspection head 18 can perform multi-axis linkage positioning relative to the tooth surface of the gear under test, thereby accurately reaching the specified tooth position and cross-sectional position.

[0027] In this embodiment, a display screen 2 and a tri-color warning light 3 are also fixedly installed on the detection body 1. The display screen 2 is located above the detection area of ​​the detection body 1 and faces the operator, and is used to display information such as detection results, current imaging parameters, and equipment operating status in real time. The tri-color warning light 3 is located on the top of the detection body 1 and is used to indicate the equipment operating status through red, yellow, and green lights. For example, a solid green light indicates normal operation, a flashing yellow light indicates a warning or standby mode, and a solid or flashing red light indicates a fault or detection abnormality.

[0028] The visual inspection camera 16, lens and light source assembly 17, and probe inspection head 18 work together to perform optical inspection of gears. The inspection device also includes a controller. The controller can be an industrial computer, an embedded industrial control computer, or a programmable logic controller, which is electrically connected to the drive motor 4, the first hydraulic cylinder 9, the second hydraulic cylinder 13, the visual inspection camera 16, the lens and light source assembly 17, and the probe inspection head 18.

[0029] The controller is configured to perform the following gear optical inspection steps: Step S1: Obtain the tooth profile light intensity modulation feature factor based on the grayscale data of the tooth profile image collected by the visual inspection camera 16; Step S2: Based on the tooth profile light intensity modulation feature factor, the tooth tip circle diameter data and tooth surface light spot offset data collected by the visual inspection camera 16, the eccentric coupling feature vector of the tooth profile inclination angle is obtained. Step S3: Based on the eccentric coupling feature vector, the tooth surface reflectivity data obtained by the lens and light source assembly 17, and the tooth profile angle data obtained by the probe detection head 18, a multi-dimensional compensation correction factor for the tooth profile is obtained. Step S4: Adjust the imaging parameters based on the tooth profile multidimensional compensation correction factor.

[0030] Through the above steps, the device can adaptively sense the surface condition and clamping status of the gear under test before or during the test, and optimize the imaging conditions accordingly, thereby laying the foundation for subsequent high-precision measurement.

[0031] The specific implementation process of each step is described below with reference to the accompanying drawings.

[0032] Step S1: Obtain the tooth profile light intensity modulation feature factor based on the grayscale data of the tooth profile image collected by the visual inspection camera 16.

[0033] Specifically, step S1 details the process of obtaining the tooth profile light intensity modulation characteristic factor, which is one of the basic data for all subsequent compensation calculations.

[0034] Please refer to Figure 3 and Figure 5 During the actual testing, the operator first sets the testing parameters through the display screen 2 and the controller, including the number of teeth z, module, and reference pressure angle α of the gear to be tested. ref Reference tooth tip circle diameter D ref Then, the controller controls the drive motor 4 to rotate the rotary table 6, aligning the first tooth position (the i-th tooth) of the gear to be tested with the testing station.

[0035] The visual inspection camera 16 is used to acquire pixel grayscale values ​​of each tooth position and each cross-section of the gear. Specifically, the controller drives the support frame 15 to move via the first hydraulic cylinder 9 and the second hydraulic cylinder 13, so that the focus of the visual inspection camera 16 is aligned with the tooth tip cross-section, pitch circle cross-section, and tooth root cross-section of the gear, respectively. At each cross-section position, the lens and the light source assembly 17 illuminate the tooth surface with a fixed light intensity, and the visual inspection camera 16 acquires a clear image of the tooth profile.

[0036] The controller obtains the tooth profile intensity modulation feature factor based on the ratio of the tooth surface grayscale variance to the average grayscale of the tooth surface, the ratio of the cross-sectional normal sampling length to the light-transmitting area of ​​the lens and light source assembly 17, and the reference intensity modulation factor.

[0037] In an exemplary embodiment, the process of obtaining the tooth profile intensity modulation feature factor includes: First, the pixel grayscale values ​​collected by the visual inspection camera 16 at each tooth position and cross section of the gear are obtained to obtain the grayscale variance σ and the average grayscale μ of the tooth surface.

[0038] Specifically, for the i-th tooth and the j-th cross-section position, a column or a region of pixel grayscale values ​​are extracted along the tooth profile normal direction. Let the region have n pixels, and the grayscale value of the k-th pixel be I. k ,but: ; ; n is the total number of pixels, I k Let I be the grayscale value of the k-th pixel. avg This represents the pixel average.

[0039] Next, the cross-sectional normal sampling length L along the tooth profile normal direction and the light-transmitting area S of the lens and light source assembly 17 are obtained. The cross-sectional normal sampling length L is obtained by multiplying the pixel equivalent of the visual inspection camera 16 by the number of sampled pixels. The pixel equivalent is obtained by calibration using a standard calibration plate before inspection. The light-transmitting area S is calculated based on the current lens aperture setting value, which is a known fixed value or can be read by the controller.

[0040] Then, the ratio of the tooth surface grayscale variance to the average tooth surface grayscale is multiplied by the ratio of the cross-sectional normal sampling length to the light-transmitting area, and then divided by the reference intensity modulation factor to obtain the tooth profile intensity modulation feature factor. Its quantization method is as follows: ; Where: TSMF ij σ is the characteristic factor for controlling the light intensity of the tooth profile at the j-th section of the i-th tooth position. ij The variance of grayscale values ​​on the tooth surface is μ, which is extracted from the image captured by the visual inspection camera 16 at the i-th tooth and j-th cross-section positions along the tooth profile normal direction. ij L represents the average gray level of the tooth surface. ij S is the cross-sectional normal sampling length, representing the physical sampling length along the tooth profile normal direction. It is obtained by multiplying the pixel equivalent of the visual inspection camera 16 by the number of sampled pixels. The pixel equivalent is pre-calibrated using a calibration plate. ij TSMF is the effective light-gathering area of ​​the lens aperture. ref As a reference intensity modulation factor; This reflects the ratio of grayscale variance to average grayscale. Physically, the greater the surface roughness of the teeth, the more severe the scattering of reflected light, leading to increased pixel grayscale fluctuation (σ). ij Increase), while diffuse reflection reduces the overall brightness (μ). ij (This ratio decreases), therefore it is positively correlated with tooth surface roughness. This utilizes the basic principle that the ratio of variance to mean in speckle statistics is used as an indicator of surface roughness.

[0041] This reflects the ratio of sampling length to light-transmitting area. The larger the sampling length, the more tooth surface areas are included in the calculation, resulting in better statistical representativeness; the smaller the light-transmitting area (narrower aperture), the more significant the diffraction effect, the lower the edge contrast, and the greater the weight required to compensate.

[0042] Combining multiplication into multiplication The tooth profile light intensity control characteristic factor TSMF was then obtained. ij The larger the value, the more severe the interference of the tooth surface roughness at that tooth position section with optical detection, and the greater the compensation required in subsequent calculations.

[0043] Thus, the tooth profile intensity modulation characteristic factor TSMF was obtained. ij This factor is a dimensionless ratio, and its physical meaning lies in quantifying the degree to which the micro-roughness of the tooth surface modulates the intensity of reflected light. When the tooth surface roughness increases, the speckle effect intensifies, the gray-level variance increases, and diffuse reflection leads to a decrease in average gray-level; therefore, TSMF... ij The value increases. The introduction of this factor provides a crucial quantitative basis for subsequently distinguishing between imaging interference caused by tooth surface roughness and imaging changes caused by geometry.

[0044] Step S2: Based on the tooth profile light intensity modulation feature factor, the tooth tip circle diameter data and tooth surface light spot offset data collected by the visual inspection camera 16, the eccentric coupling feature vector of the tooth profile inclination angle is obtained.

[0045] Step S2, based on step S1, elaborates in detail how to obtain the feature vector used to characterize the inclination angle and eccentricity coupling effect by combining the tooth profile light intensity modulation feature factor with the tooth tip circle diameter and spot offset data.

[0046] After obtaining the TSMF for each tooth position and each cross section ij After the values ​​are obtained, the controller further processes these data.

[0047] In an exemplary embodiment, the process of obtaining the eccentric coupling feature vector includes: First, obtain the profile smoothness modulation characteristic factors of the tooth tip section, pitch circle section, and tooth root section for all tooth positions, and denote the profile smoothness modulation characteristic factor of the tooth tip section as the tooth tip section smoothness modulation factor TSMF. i,top The characteristic factor for the intensity of tooth profile light intensity at the tooth root section is denoted as the tooth root section intensity of light intensity (TSMF). i,root The characteristic factor for the intensity of tooth profile light intensity at the pitch circle section is denoted as the pitch circle section intensity of light intensity (TSMF). i,pitch .

[0048] Secondly, the product of the light intensity control factor of the tooth tip section and the light intensity control factor of the tooth root section is divided by the square of the light intensity control factor of the pitch circle section to obtain the tooth profile section inclination effect ratio.

[0049] Understandably, the angle between the tooth surface normal and the optical axis of the optical system is larger in the tooth tip and root regions compared to the pitch circle region. When there is an angle on the tooth surface, the reflected light path deviates more severely, leading to TSMF (Total Surface Motion Fading). ij The value increases more significantly. Therefore, this ratio can effectively amplify the tilt angle effect and suppress the influence of the common modulus of tooth surface roughness.

[0050] Next, obtain the reference tooth tip circle diameter D. ref and the measured average tooth tip circle diameter D collected by the visual inspection camera 16 i,avgThe ratio of the reference tooth tip circle diameter to the measured average tooth tip circle diameter is used as the tooth position radial deviation ratio factor.

[0051] Measured average tooth tip circle diameter D i,avg The diameter value is obtained by fitting a circle to the edge of the tip arc of the i-th tooth at multiple points. When there is clamping eccentricity, the D value varies for different tooth positions. i,avg It will fluctuate in a sinusoidal pattern, deviating from D. ref .

[0052] Then, the lateral offset Δx of the centroid of the light spot reflected from the tooth surface, acquired by the visual inspection camera 16, is obtained. i and reference spot offset Δx ref The ratio of the lateral offset of the light spot centroid to the offset of the reference light spot is used as the normalization index of the reflected light path offset.

[0053] Finally, the ratio of tooth profile inclination angle effect, the tooth position radial deviation proportionality factor, and the reflection optical path offset normalization index are multiplied together and then divided by the reference normalization factor to obtain the eccentric coupling characteristic vector of tooth profile inclination angle.

[0054] Its quantification method is as follows: ; Where: TECV i Let be the eccentric coupling feature vector of the i-th tooth position, representing the combined influence of the tooth surface inclination angle and clamping eccentricity on imaging distortion at the i-th tooth position. TSMF i,top TSMF is the light intensity modulation factor of the tooth tip section. i,root TSMF is the light intensity control factor of the tooth root section. i,pitch D is the intensity control factor for the pitch circle section. ref The reference addendum circle diameter, as indicated on the gear design drawing, is a standard known value, D. i,avg To determine the measured average tip circle diameter of the i-th tooth, the visual inspection camera 16 acquires an image of the i-th tooth. Then, an edge extraction algorithm is used to measure the fitted diameter of the tip circle arc. The average value of multiple cross-sectional measurements of this tooth is taken, Δx. i The lateral offset of the centroid of the light spot on the i-th tooth is the pixel coordinates of the centroid of the light spot formed by the reflection of the lens and the light source assembly 17 on the tooth surface in the image of the i-th tooth acquired by the visual inspection camera 16, compared to the theoretical centroid coordinates (determined during calibration), Δx. ref K is the reference spot offset, reflecting the lateral offset of the spot centroid measured under the same illumination conditions by a standard calibration gear (a known defect-free, high-precision gear). norm The values ​​measured for standard gears under calibrated conditions. Result value; In the middle, the molecule is the product of the intensity modulation factor of the tooth tip section and the tooth root section ( These two sections are located at the upper and lower ends of the tooth profile, respectively. The tooth surface inclination angle is the largest (the angle between the tooth tip normal and the vertical direction is large, and the same is true for the tooth root). Therefore, the product amplifies the inclination angle effect; the denominator is the square of the light intensity suppression factor of the pitch circle section ( At the pitch circle, the tooth surface normal is nearly horizontal (for spur gears), and the tilt angle is minimal, serving as a reference for the tilt effect. In existing technologies, the tooth surface tilt angle is typically measured individually using a mechanical angle gauge or a laser rangefinder. However, this embodiment indirectly characterizes the tilt angle through the ratio of the three cross-sectional TSMFs. This is because the angle between the tooth surface normal and the vertical direction is largest at the tooth tip and root (for spur gears, the angle between the tooth tip normal and the radial line is approximately α + γ, where α is the pressure angle and γ is the tooth tip angle), while the normal at the pitch circle is nearly horizontal. The larger the tooth surface tilt angle, the more the reflected light deviates from the incident direction, resulting in a more diffuse and offset light spot on the camera sensor—these effects are precisely encoded in the TSMF. Therefore, the three cross-sectional TSMFs... ij The ratio relationship implicitly contains information about the tooth surface inclination angle, which can be indirectly characterized without directly measuring the inclination angle. Thus, the overall ratio ( This reflects the degree to which the tooth surface inclination angle deviates from the reference. As the tooth surface inclination angle increases, the reflected light offset at the tooth tip and root intensifies, increasing TSMF. ij As the ratio increases, the change at the nodal circle is smaller, serving as a stable denominator.

[0055] It is the ratio of the reference tooth tip circle diameter to the measured average tooth tip circle diameter. If there is eccentricity in the gear clamping, during one revolution of the rotary table 6, the measured average tooth tip circle diameter fluctuates sinusoidally, D. i,avg Deviation from D ref This ratio quantifies the radial error caused by eccentricity: the further the ratio deviates from 1, the more severe the eccentricity. Division is used here instead of subtraction because the measurement error of the tooth tip circle diameter is reflected as a proportional deviation in the division relationship, which is more in line with the geometric similarity relationship.

[0056] It is the ratio of the actual light spot offset to the reference offset. The larger the tooth surface tilt angle, the greater the offset of the reflected light spot on the sensor, Δx. i The larger the value, the greater the value divided by Δx ref To achieve normalization, the influence of system factors such as lighting conditions and camera installation angle is eliminated; Thus, the eccentric coupling feature vector TSMF of the i-th tooth has been obtained. ij This feature vector comprehensively reflects the coupled effects of three geometric distortion factors—tooth surface inclination angle, clamping eccentricity, and optical path offset—at this tooth position. By traversing all tooth positions, a set of TECVs can be obtained. i(i=1,...,z), this set of data reflects the distribution pattern of coupling distortion along the circumferential direction of the gear. This provides a basis for the subsequent calculation of the global compensation factor.

[0057] Step S3: Based on the eccentric coupling feature vector, the tooth surface reflectivity data obtained by the lens and light source assembly 17, and the tooth profile angle data obtained by the probe detection head 18, a multi-dimensional compensation correction factor for the tooth profile is obtained.

[0058] Step S3, based on step S2, elaborates on how to fuse optical data and contact probe data to obtain a global, multi-dimensional compensation correction factor.

[0059] The controller acquires the eccentric coupling feature vector TECV for all tooth positions. i and the pitch circle section light intensity modulation factor (TSMF) of each tooth position. i,pitch Then, the tooth surface reflectivity data and tooth profile angle data were further combined.

[0060] In an exemplary embodiment, the process of obtaining the tooth profile multi-dimensional compensation correction factor includes: First, obtain the eccentric coupling feature vector TECV of the tooth profile inclination angle for all tooth positions. i The pitch circle section light intensity modulation factor (TSMF) corresponding to the pitch circle section i,pitch The sum of the products, divided by the number of teeth z and the normalized reference intensity modulation factor TSMF ref The product of these two values ​​yields the average coupling distortion ratio across the entire tooth circumference.

[0061] Understandably, due to TSMF ref Normally normalized to 1, the formula can be simplified to the weighted TECV. i Calculate the average value. This value reflects the average degree of optical distortion caused by tilt and eccentricity along the entire circumference of the gear.

[0062] Secondly, the average reflectivity R of the tooth surface is obtained by calculating the reflected light intensity received by the visual inspection camera 16 after the tooth surface is illuminated by the lens and light source assembly 17 with a fixed incident light intensity. mean .

[0063] Specifically, the controller controls the lens and light source assembly 17 to emit incident light of known intensity I. incident And control the visual inspection camera 16 to receive the reflected light intensity I reflected For each tooth position, the reflectivity is calculated, and then averaged over all tooth positions to obtain R. mean The specific calculation is as follows: ; Simultaneously, the standard deviation α of the tooth profile angle obtained by the probe detection head 18 touching the tooth surface is acquired. stdand minimum tooth profile angle α min Driven by the second hydraulic cylinder 13, the probe head 18 probes multiple points along the tooth profile normal direction to obtain the angle between the normal direction and the radial line at each point, i.e., the tooth profile angle. The tooth profile angles of all measurement points are statistically analyzed, and their standard deviation and minimum value are calculated.

[0064] Then, the average reflectivity R of the tooth surface is... mean Divide by the sum of the standard deviation of the tooth profile angle and the minimum tooth profile angle, then divide by the reference pressure angle α. ref The ratio of the two values ​​is used to obtain the matching trade-off coefficient. The matching trade-off coefficient reflects the matching relationship between the optical properties (reflectivity) of the tooth surface and the geometric consistency (standard deviation of tooth profile angle). The higher the reflectivity, the better the image quality and the lower the need for compensation; the worse the tooth profile angle consistency, the more likely there are machining errors or defects on the tooth surface, requiring stronger compensation.

[0065] Finally, the average coupling distortion ratio across the entire tooth circumference is multiplied by the matching trade-off coefficient to obtain the tooth profile multidimensional compensation correction factor TPCF, which is quantified as follows: ; In the formula: TPCF is the multi-dimensional compensation correction factor for tooth profile, z is the number of teeth of the gear, tf is the design parameter of the gear under test, and TSMF is the design parameter of the gear under test. ref To reference the intensity modulation factor, the TSMF value measured at the pitch circle section by a standard calibrated gear (known for its high precision) under the same testing conditions is used as a benchmark. mean Let α be the mean reflectance of the tooth surface. std To calculate the standard deviation of the tooth profile angle, the probe head 18 probes multiple points along the tooth profile to obtain the angle between the normal and the radial line at each point, and then calculates its standard deviation (in degrees). min The minimum tooth profile angle, the minimum value (in degrees) of the tooth profile angle in the same set of touch test data, is used to prevent the denominator from being zero. α ref The reference pressure angle; In the middle, the molecule is the TECV for all teeth. i With the corresponding nodal circle section TSMF i,pitch Summing the products of TECV. i Already in TECV i The calculation of TSMF couples tilt angle and eccentricity information. i,pitch As the reference section weight of the pitch circle, the product of the two results in the coupling error of each tooth being accumulated according to the reference section weight; the denominator is the number of teeth z and the reference light intensity modulation factor TSMF. ref Multiplication, z is used for mean averaging, TSMF ref It is used for normalization to a standard benchmark, but it is worth noting that... China has already compared TSMF with TSMF ref Normalization, TSMF ref =1, therefore, in this denominator z×TSMF ref It can be simplified to z×1. It reflects the average degree of coupling distortion across the entire tooth circumference and the proportion of deviation from the standard reference.

[0066] At this point, (Average coupling distortion across the entire periodontal region) and The product of (image quality and tooth profile consistency trade-offs) yields the final global compensation correction factor TPCF. The TPCF calculation result is fed back to the electric adjustment mechanism of the lens and light source assembly 17 via an industrial control computer, for example: If TPCF > 1, it indicates significant coupling distortion, requiring increased exposure (increased S). ij And adjust the focus position to improve image quality; If TPCF < 1, it indicates that the detection conditions are good, and the exposure can be appropriately reduced to improve the detection speed. When TPCF=1, it means that the current imaging conditions are the same as those during calibration, and the measurement results do not need to be corrected.

[0067] Step S4: Adjust the imaging parameters based on the tooth profile multidimensional compensation correction factor.

[0068] Step S4, based on step S3, elaborates in detail how to use the tooth profile multi-dimensional compensation correction factor for feedback control, and the process of multi-dimensional parameter measurement under optimal imaging conditions.

[0069] In an exemplary embodiment, the process of comparing the tooth profile multidimensional compensation correction factor TPCF with a preset convergence range includes: The controller has a preset convergence range [TPCF] low TPCF high For example, [0.95, 1.05]. This range represents the permissible imaging distortion tolerance of the detection system.

[0070] If the tooth profile multidimensional compensation correction factor TPCF exceeds the convergence range, a feedback control command is generated based on the value of the tooth profile multidimensional compensation correction factor to adjust the light transmission area, focus position, or illumination intensity of the lens and light source assembly 17, and the process of acquiring the tooth profile light intensity modulation feature factor is returned to re-acquire the image and recalculate until the tooth profile multidimensional compensation correction factor converges to the convergence range.

[0071] Specifically, in the feedback control process: When the tooth profile multidimensional compensation correction factor TPCF is greater than the upper limit of the convergence range (TPCF > TPCF) highWhen the aperture is closed (i.e., the aperture is stopped down), it indicates that the coupling distortion is large and the image quality is poor. At this time, the controller generates a control command to reduce the light-transmitting area of ​​the aperture in the lens and light source assembly 17 (i.e., stop down the aperture) to increase the depth of field, thereby compensating for the image plane shift caused by the tooth surface tilt angle; at the same time, it fine-tunes the focus position so that the focal plane is located in the middle of the tooth profile. This adjustment process is performed by a miniature stepper motor or voice coil motor inside the lens and light source assembly 17.

[0072] When the tooth profile multidimensional compensation correction factor TPCF is less than the lower limit of the convergence range (TPCF < TPCF) low When the light intensity is too high, it indicates that the detection conditions are good, or even that the signal may saturate due to excessive light. At this time, the controller generates control commands to increase the illumination intensity or exposure time to improve the image signal-to-noise ratio, and adjusts the illumination angle to optimize the reflected light path, making the image details richer.

[0073] After each adjustment, the device executes steps S1 to S3 again, calculates a new TPCF value, and compares it with the convergence range. This process is repeated iteratively until the TPCF falls within the convergence range.

[0074] Understandably, this closed-loop control strategy based on global compensation factors enables the device to adaptively cope with gears of different roughness and different clamping states, and always work under optimal imaging conditions.

[0075] In an exemplary embodiment, once the multi-dimensional compensation correction factor for the tooth profile converges to the convergence range, it is determined that the current imaging conditions meet the high-precision detection requirements. At this time, the controller controls the visual inspection camera 16 and the probe inspection head 18 to remeasure the parameters of the gear in four dimensions—length, angle, area, and irregular surface or contour—under optimal imaging conditions.

[0076] It is worth noting that TPCF can not only serve as the basis for feedback control, but it can also be used as a correction coefficient to compensate for the original measured value. The specific compensation method is as follows: For length measurements (such as tooth thickness s): After the visual inspection camera 16 acquires the tooth profile image, the tooth profile boundary is obtained through an edge extraction algorithm, and the original tooth thickness value s is calculated. raw Because edge extraction is affected by imaging distortion, resulting in a one-dimensional linear drift, the corrected tooth thickness is: (tooth thickness s): s corr =s raw ×TPCF; Specifically, the tooth thickness s is measured by acquiring a tooth profile image through a visual inspection camera 16, extracting the tooth profile boundary points on the image, calculating the pixel distance between the same boundary points of two adjacent teeth, and then multiplying it by the pixel equivalent to convert it into physical length.

[0077] When imaging link distortion exists (such as rough tooth surfaces causing edge blurring, or tilt angle causing optical path offset), the extraction position of boundary points will undergo a unidirectional linear drift. Edge blurring causes boundary points to shrink towards the center of the grayscale gradient, while tilt angle offset causes boundary points to shift to one side. This drift is one-dimensional and linear, meaning that the boundary position offset Δs is proportional to the degree of distortion. s raw =s true +Δs≈s true ×TPCF; Therefore, when correcting, multiplying the original value by TPCF directly results in a one-dimensional linear scaling correction. When TPCF > 1, the original value is magnified; when TPCF < 1, the original value is shrunk.

[0078] For angle measurement (such as pressure angle α): the probe head 18 touches and obtains the raw value of pressure angle α. raw Considering that the probe is significantly affected by the surface roughness of the tooth, a pitch circle section light intensity control factor is used for correction. ; The pressure angle α is measured by probing multiple points on the tooth surface using the probe head 18, fitting the normal direction of each point, and then calculating the angle between the normal and the radial line. The main source of error in this measurement is the interference of tooth surface roughness on the positioning of the contact point. A rough tooth surface will cause the probe contact point to deviate from the theoretical contact point, thereby changing the fitted normal direction.

[0079] TPCF integrates multiple factors such as tilt angle, eccentricity, and optical path offset. For probe contact testing, the impact of tilt angle and eccentricity on contact positioning is far less than the impact of surface roughness. Therefore, a parameter that focuses more on the influence of surface roughness is needed to correct the pressure angle.

[0080] This parameter, TSMF, encodes the effect of tooth surface roughness on optical imaging, while the ratio of the pitch circle section TSMF to the reference TSMF reflects the degree of deviation of the tooth surface roughness at the pitch circle relative to the standard reference. The average deviation across all tooth positions is obtained. This ratio is used to correct the pressure angle; essentially, when the tooth surface roughness deviates from the reference, the positioning accuracy of the probe decreases, requiring scaling the measured value of the pressure angle according to the degree of deviation.

[0081] For area measurement (e.g., defect area A): After the visual inspection camera 16 acquires images of the tooth surface, the defect area is segmented, and the original value A is obtained by counting the pixel areas. raw Since area is a two-dimensional quantity, edge drift contributes in both dimensions, therefore the corrected area is: A corr =A raw ×TPCF 2 ; The defect area A is measured by acquiring tooth surface images through the visual inspection camera 16, performing image segmentation (threshold segmentation or edge detection) on the defect area, counting the number of pixels in the defect area, and then multiplying it by the square of the pixel equivalent to convert it into physical area.

[0082] It's worth noting that area is a two-dimensional quantity. The boundary of a defect region in an image is defined by edge points in both the x and y directions. When imaging distortion causes edge drift, the drift in both dimensions contributes to the area error.

[0083] As previously explained, the linear drift in a single dimension is proportional to the TPCF. Therefore, in a two-dimensional plane, the drift ratio of the defect region in the x-direction is TPCF. x The drift ratio in the y-direction is TPCF y If the distortion is the same in both directions (isotropic), then the change in area is: A raw ≈A true ×TPCF x ×TPCF y =A true ×TPCF 2 .

[0084] For measurement of irregular surfaces or profiles (such as tooth profile deviation f): the measurement relies on both visual images and probe data, and the error sources include both global imaging distortion and single-tooth coupling distortion. Therefore, the corrected tooth profile deviation is: ; The measurement of tooth profile deviation f is the most complex. It relies on both the image data from the visual inspection camera 16 and the touch data from the probe inspection head 18. It is the result of the fusion of non-contact optical data and contact data.

[0085] The error sources of tooth profile deviation are affected by both imaging link distortion (characterized by TPCF) and coupling distortion of a single tooth position (characterized by TECV). Therefore, the errors at both levels need to be considered when making corrections.

[0086] Finally, the controller displays the corrected length, angle, area, and contour measurements on display screen 2, and controls the tri-color warning light 3 to output corresponding status signals based on whether the detection results exceed tolerances. For example, if all parameters are within tolerance, the tri-color warning light 3 displays green; if there are any out-of-tolerance items, it displays red and issues an alarm.

[0087] This completes the closed-loop detection process from adaptive imaging parameter adjustment to multi-dimensional measurement value correction, significantly improving the accuracy and repeatability of high-precision gear detection.

[0088] It should be noted that any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this invention should also be within the scope of protection of this invention.

Claims

1. An optical inspection device for high-precision gears, characterized in that, The device includes a detection body (1), on which a rotary table (6), a drive motor (4), and a transmission housing (5) are mounted. The drive motor (4) is connected to the transmission housing (5) and the rotary table (6) in a transmission relationship. A first guide rail bracket (8) and an auxiliary rail frame (11) are fixedly mounted on the surface of the detection body (1) in the detection area. A first drive rail (10) and a first hydraulic cylinder (9) are fixedly mounted on the first guide rail bracket (8). The piston rod of the first hydraulic cylinder (9) is driven by the slide of the first drive rail (10). The first drive rail (10) and the auxiliary rail frame (11) are connected, and a second rail bracket (12) is slidably mounted on the first drive rail (10) and the auxiliary rail frame (11). A second hydraulic cylinder (13) and a second drive rail (14) are fixedly mounted on the surface of the second rail bracket (12). The piston rod of the second hydraulic cylinder (13) is connected to the slide table of the second drive rail (14) in a transmission connection. A support frame (15) is slidably mounted on the second rail bracket (12) along the second drive rail (14). A visual inspection camera (16), a lens and light source assembly (17) and a probe inspection head (18) are fixedly mounted on the support frame (15). The visual inspection camera (16), the lens and light source assembly (17), and the probe inspection head (18) cooperate to perform gear optical inspection. The inspection device also includes a controller configured to perform the following gear optical inspection steps: Based on the grayscale data of the tooth profile image collected by the visual inspection camera (16), the tooth profile light intensity modulation feature factor is obtained; based on the tooth profile light intensity modulation feature factor, the tooth tip circle diameter data and the tooth surface spot offset data collected by the visual inspection camera (16), the eccentric coupling feature vector of the tooth profile tilt angle is obtained. Based on the eccentric coupling feature vector, the tooth surface reflectivity data obtained by the lens and light source assembly (17), and the tooth angle data obtained by the probe detection head (18), a multi-dimensional compensation correction factor for the tooth profile is obtained; the imaging parameters are adjusted based on the multi-dimensional compensation correction factor for the tooth profile.

2. The optical inspection device for high-precision gears according to claim 1, characterized in that, The rotary table (6) is fixedly installed with four positioning fixtures (7) on the upper surface of the detection area. The detection body (1) is also fixedly equipped with a display screen (2) and a three-color warning light (3). The display screen (2) is located above the detection area of ​​the detection body (1), and the three-color warning light (3) is located on the top of the detection body (1). The display screen (2) is used to display the detection results, and the three-color warning light (3) is used to indicate the operating status of the equipment.

3. An optical inspection method for high-precision gears, applied to the optical inspection device for high-precision gears as described in claim 2, characterized in that, include: The visual inspection camera (16) is used to collect the pixel gray values ​​of each tooth position and each cross section of the gear, and based on the ratio of the tooth surface gray variance to the average gray value of the tooth surface, the ratio of the cross section normal sampling length to the light transmission area of ​​the lens and light source assembly (17), and the reference light intensity modulation factor, the tooth profile light intensity modulation feature factor is obtained. Based on the ratio calculation of the tooth profile light intensity modulation characteristic factor in the tooth tip section, pitch circle section and tooth root section, combined with the ratio of the reference tooth tip circle diameter to the measured average tooth tip circle diameter and the ratio of the lateral offset of the light spot centroid to the offset of the reference light spot, the eccentric coupling characteristic vector of the tooth profile inclination angle is obtained. Based on the weighted fusion of the eccentric coupling feature vector and the tooth profile light intensity modulation feature factor, and combined with the fusion result of the mean tooth surface reflectivity and the tooth profile angle statistical parameters, a multi-dimensional compensation correction factor for the tooth profile is obtained. The tooth profile multidimensional compensation correction factor is compared with the preset convergence range until the tooth profile multidimensional compensation correction factor converges to the convergence range. Based on the corrected imaging parameters, the visual inspection camera (16) and the probe inspection head (18) are controlled to inspect the gear, and the inspection results are obtained and output.

4. The optical inspection method for high-precision gears according to claim 3, characterized in that, The process of obtaining the tooth profile light intensity modulation feature factor includes: Obtain the pixel grayscale values ​​collected by the visual inspection camera (16) at each tooth position and each cross section of the gear, and obtain the grayscale variance and average grayscale of the tooth surface; Obtain the cross-sectional normal sampling length along the tooth profile normal direction and the light-transmitting area of ​​the lens and light source assembly (17); Multiply the ratio of the tooth surface grayscale variance to the tooth surface average grayscale by the ratio of the cross-sectional normal sampling length to the light-transmitting area, and then divide by the reference light intensity modulation factor to obtain the tooth profile light intensity modulation feature factor. The reference light intensity modulation factor is obtained by the standard gear in the same way during the calibration phase.

5. The optical inspection method for high-precision gears according to claim 3, characterized in that, The process of obtaining the eccentric coupling feature vector includes: Obtain the profile light intensity modulation characteristic factors of the tooth tip section, pitch circle section and tooth root section of all tooth positions, and record the profile light intensity modulation characteristic factor of the tooth tip section as the tooth tip section light intensity modulation factor, the profile light intensity modulation characteristic factor of the tooth root section as the tooth root section light intensity modulation factor, and the profile light intensity modulation characteristic factor of the pitch circle section as the pitch circle section light intensity modulation factor. The product of the light intensity control factor of the tooth tip section and the light intensity control factor of the tooth root section is divided by the square of the light intensity control factor of the pitch circle section to obtain the tooth profile section inclination effect ratio. Obtain the reference tooth tip circle diameter and the measured average tooth tip circle diameter collected by the visual inspection camera (16), and use the ratio of the reference tooth tip circle diameter to the measured average tooth tip circle diameter as the tooth position radial deviation ratio factor. The lateral offset of the centroid of the light spot reflected from the tooth surface and the offset of the reference light spot are obtained by the visual inspection camera (16), and the ratio of the lateral offset of the centroid of the light spot to the offset of the reference light spot is used as the normalization index of the reflected light path offset. Multiply the tooth profile section inclination effect ratio, the tooth position radial deviation proportional factor, and the reflected light path offset normalization index, and then divide by the reference normalization factor to obtain the eccentric coupling characteristic vector of the tooth profile inclination angle. The reference normalization factor is obtained by the standard gear in the same way as the tooth profile section inclination effect ratio during the calibration phase.

6. The optical inspection method for high-precision gears according to claim 3, characterized in that, The process of obtaining the multi-dimensional compensation correction factor for the tooth profile includes: The sum of the products of the eccentric coupling feature vector of the tooth profile inclination angle of all tooth positions and the light intensity control factor of the corresponding pitch circle section is obtained, and divided by the product of the number of teeth and the normalized reference light intensity control factor, to obtain the average coupling distortion ratio of the entire tooth circumference. The average reflectance of the tooth surface is obtained by calculating the reflected light intensity received by the visual inspection camera (16) after the lens and light source assembly (17) illuminates the tooth surface with a fixed incident light intensity. The standard deviation of the tooth profile angle and the minimum tooth profile angle obtained by the probe detection head (18) touching the tooth surface are obtained. The average reflectance of the tooth surface is divided by the sum of the standard deviation of the tooth profile angle and the minimum tooth profile angle and then divided by the reference pressure angle to obtain the matching trade-off coefficient. The tooth profile multidimensional compensation correction factor is obtained by multiplying the average coupling distortion ratio of the entire tooth circumference with the matching trade-off coefficient.

7. The optical inspection method for high-precision gears according to claim 3, characterized in that, The process of comparing the multi-dimensional tooth profile compensation correction factor with the preset convergence range includes: If the tooth profile multidimensional compensation correction factor exceeds the convergence range, a feedback control command is generated based on the value of the tooth profile multidimensional compensation correction factor to adjust the light transmission area, focus position or illumination intensity of the lens and light source assembly (17), and the process of acquiring the tooth profile light intensity modulation feature factor is returned to re-acquire the image and calculate until the tooth profile multidimensional compensation correction factor converges to the convergence range.

8. The optical inspection method for high-precision gears according to claim 7, characterized in that, During the feedback control process, when the tooth profile multi-dimensional compensation correction factor is greater than the upper limit of the convergence range, the light-transmitting area is reduced and the focus position is adjusted to increase the depth of field and compensate for the image plane shift caused by the tooth surface tilt angle. When the tooth profile multidimensional compensation correction factor is less than the lower limit of the convergence range, the illumination intensity and exposure time are increased to improve the signal-to-noise ratio, and the illumination angle is adjusted to optimize the reflected light path.

9. The optical inspection method for high-precision gears according to claim 7, characterized in that, After the multi-dimensional compensation correction factor of the tooth profile converges to the convergence range, under the optimal imaging conditions, the parameters of the gear's length, angle, area and irregular surface or contour are remeasured by the visual inspection camera (16) and the probe inspection head (18), and the detection results are displayed on the display screen (2), and the status signal is output by the three-color warning light (3).

Images