A kind of deviation rectifying device based on laser displacement feedback

Abstract

The application relates to the technical field of precision measurement, in particular to a deviation rectifying device based on laser displacement feedback, which comprises two perpendicular arrangement of the laser displacement sensor, the two sides of the laser displacement sensor are respectively provided with two deviation rectifying components arranged along the X-axis direction, the center line of the accommodating openings of the two deviation rectifying components extends to the detection plane of the laser displacement sensor along the X-axis direction, the two deviation rectifying components are respectively connected with displacement driving components, the displacement driving components are electrically connected with the laser displacement sensor through a control device, and the control device controls the displacement driving components to drive the deviation rectifying components to realize synchronous displacement rectification. In the application, the control device can control the displacement driving components to drive the deviation rectifying components to realize synchronous displacement rectification according to the information fed back by the laser displacement sensor, so that fast and accurate rectification operation is realized. The design has compact structure, rapid response, high rectification precision, can effectively improve the production efficiency and product quality, and has wide application prospect.

Description

Technical Field

[0001] This application relates to the field of precision measurement technology, and in particular to a correction device based on laser displacement feedback. Background Technology

[0002] Laser displacement sensors, with their non-contact and high-precision characteristics, are widely used in dynamic diameter measurement of regular objects such as cables and cylinders. However, as the manufacturing industry continues to demand higher dimensional accuracy from products, the limitations of traditional laser displacement measurement systems are becoming increasingly apparent.

[0003] Currently, most laser displacement measurement systems still rely on manual intervention to position the measured object. In continuous automated production lines, repeated manual adjustments not only severely restrict production efficiency but also inevitably introduce secondary errors due to human operation, making it difficult to meet the dual demands of modern industry for high precision and high efficiency. Furthermore, traditional measuring devices have extremely stringent requirements for the installation reference surface; even minute installation deviations can significantly affect the accuracy of measurement results, and their lack of robustness is particularly prominent in precision manufacturing. In addition, existing systems generally lack dynamic interference compensation mechanisms, making it impossible to respond in real time to environmental vibrations common in industrial environments. Periodic vibrations of production line motors and random swaying of the measured object caused by the acceleration impact of conveyor belts generate high-frequency interference, leading to a sharp decline in measurement stability and making it difficult to adapt to complex and ever-changing dynamic industrial conditions.

[0004] Therefore, overcoming the problems of decreased measurement accuracy and measurement offset caused by position deviation in existing laser displacement measurement systems, and achieving high-precision dynamic measurement, has become a technical challenge that urgently needs to be solved in this field. Utility Model Content

[0005] The purpose of this application is to provide a correction device based on laser displacement feedback to solve the problems in the existing device, such as the fixed and unadjustable workpiece measurement position and the low measurement accuracy caused by the workpiece measurement position offset.

[0006] The embodiments of this application can be implemented through the following technical solutions:

[0007] A correction device based on laser displacement feedback includes two through-beam laser displacement sensors arranged in a vertical direction, namely a first laser displacement sensor group and a second laser displacement sensor group. The detection plane constructed with respect to the laser displacement sensors is defined as the X-axis direction. Correction components are respectively arranged on both sides of the laser displacement sensors along the X-axis direction. The line connecting the centers of the receiving ports of the correction components on both sides extends along the X-axis direction into the detection plane of the laser displacement sensors.

[0008] The correction component is connected to a displacement driving component, which is electrically connected to a laser displacement sensor via a control device. The control device controls the displacement driving component to drive the center line of the receiving port of the correction component and the second correction component to be aligned with the detection plane for displacement correction.

[0009] Furthermore, taking the bottom plane of the correction component as a horizontal reference, the direction perpendicular to the preset X-axis and within this horizontal plane is defined as the Y-axis direction. The correction component includes a support frame and support blocks. The top center of the support frame has a U-shaped opening that runs through the X-axis. Two support blocks are provided. One end of each support block is hinged to the two sides of the top of the support frame and is arranged opposite each other along the Y-axis. The other end of each support block has an opening slot that runs through the X-axis. When both support blocks rotate to the U-shaped opening of the support frame, the opening slots of the two support blocks abut against each other to form a receiving opening.

[0010] Furthermore, the lower part of the receiving opening is V-shaped, and the two inclined surfaces of the V-shaped receiving opening are symmetrical.

[0011] Furthermore, taking the bottom plane of the correction component as a horizontal reference, the direction perpendicular to the preset X-axis and within the horizontal plane is defined as the Y-axis direction, and the direction perpendicular to the X-axis and Y-axis and perpendicular to the horizontal plane upward is defined as the Z-axis direction. The displacement driving component includes a first displacement driving component arranged along the Z-axis direction and a second displacement driving component arranged along the Y-axis direction. The bottom of the correction component is connected to the output end of the first displacement driving component, and the first displacement driving component is connected to the output end of the second displacement driving component.

[0012] Furthermore, the first displacement driving component and the second displacement driving component are a lead screw composite drive. The first displacement driving component includes a first support frame, a first lead screw, a first motor, and a first nut. The first lead screw is rotatably disposed in the first support frame along the Z direction. The first motor is fixedly connected to the first support frame, and the output end of the first motor is connected to the first lead screw. The first nut is slidably connected to one side of the first support frame along the Z direction and is threadedly connected to the first lead screw. The first lead screw is fixedly connected to the correction component.

[0013] Furthermore, the rays emitted from the ray ends of the first laser displacement sensor group and the second laser displacement sensor group each form a 45° angle with the horizontal plane.

[0014] Furthermore, the first laser displacement sensor group and the second laser displacement sensor group are integrated within a frame. The frame includes a frame body, and a square opening is provided in the middle of the frame body along the X-axis. The diagonals of the square opening intersect along the Z-axis and Y-axis directions, and the top of the square opening is open.

[0015] Furthermore, the frame is provided with a plurality of limiting protrusions, which are distributed along the periphery of the square opening. The four walls of the square opening are respectively provided with mounting notches, and the sensing head of the laser sensor is installed at the mounting notches. The sensing head is confined between the wall of the frame and the adjacent limiting protrusion.

[0016] Furthermore, a laser window is connected to the mounting notch.

[0017] The laser displacement feedback-based correction device provided in the embodiments of this application has at least the following beneficial effects:

[0018] The laser displacement feedback-based correction device in this application constructs a high-precision detection plane through two sets of vertically arranged through-beam laser displacement sensors, which can capture the positional deviation of the workpiece in real time and accurately. The precise layout of the correction components on both sides and the laser displacement sensors allows the center line of the receiving port to extend into the detection plane, ensuring efficient connection between detection and correction actions. The coordinated operation of the displacement drive component and the control device realizes fully automated closed-loop control from deviation detection to correction execution, which greatly improves the correction efficiency and accuracy, effectively avoids errors caused by manual intervention, and is suitable for industrial production scenarios with extremely high precision requirements. It provides reliable technical support for ensuring production quality and reducing the defect rate, and has advantages such as strong practicality and high reliability. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the overall structure of a laser displacement feedback-based correction device according to this application.

[0020] Figure 2 This is a schematic diagram of the overall structure of the displacement drive component in this application;

[0021] Figure 3 This is a schematic diagram of the frame after the end caps have been removed in this application;

[0022] Figure 4 For the offset in this application Indicative signage;

[0023] Figure 5 This is a pixel sequence image collected by the first laser displacement sensor group;

[0024] Figure 6 A pixel sequence image acquired by the second laser displacement sensor group;

[0025] Figure 7 This is a schematic diagram illustrating the sequence processing correction performed by the first laser displacement sensor group based on the pixel sequence acquired by the second laser displacement sensor group.

[0026] Figure 8 This is a pixel sequence image obtained by processing the pixel sequence collected by the second laser displacement sensor group based on the pixel sequence collected by the first laser displacement sensor group.

[0027] Figure 9 The image shows a pixel sequence acquired by the first laser displacement sensor group after the displacement drive component has completed the position adjustment based on the displacement correction compensation amount of the second laser displacement sensor group.

[0028] Numbers in the diagram

[0029] L1-L1': First laser displacement sensor group; L2-L2': Second laser displacement sensor group;

[0030] 1-Correction component; 3-Displacement drive component; 31-First displacement drive component; 311-First support frame; 312-First lead screw; 313-First motor; 314-First nut; 32-Second displacement drive component; 4-Control device; 6-Frame; 60-Square opening; 61-Frame body; 611-Limiting protrusion; 612-Mounting notch; 62-Laser window plate. Detailed Implementation

[0031] The present application will now be further described based on preferred embodiments and with reference to the accompanying drawings.

[0032] Furthermore, for ease of understanding, various components on the drawings have been enlarged or reduced, but this is not intended to limit the scope of protection of this application.

[0033] Singular forms of words also include plural meanings, and vice versa.

[0034] In the description of the embodiments of this application, it should be noted that if terms such as "upper," "lower," "inner," or "outer" are used to indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this application is in use, they are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this application. In addition, in the description of this application, in order to distinguish different units, the terms "first," "second," etc. are used in this specification, but these are not limited by the manufacturing order, nor should they be construed as indicating or implying relative importance. Their names may differ in the detailed description and claims of this application.

[0035] The vocabulary used in this specification is for illustrative purposes and is not intended to limit the scope of this application. It should also be noted that, unless otherwise expressly specified and limited, the terms "set," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, a direct connection, or an indirect connection via an intermediate medium; or they can refer to the internal communication between two components. Those skilled in the art will understand the specific meaning of these terms in this application.

[0036] A laser displacement feedback-based correction device is placed on a worktable S and includes two perpendicularly arranged through-beam laser displacement sensors, namely a first laser displacement sensor group L1-L1' and a second laser displacement sensor group L2-L2'. The detection plane constructed perpendicular to the laser displacement sensors is defined as the X-axis direction. Correction components 1 are respectively arranged on both sides of the laser displacement sensors along the X-axis direction. The line connecting the centers of the two correction components 1 extends along the X-axis direction and is located within the detection area of ​​the laser displacement sensors. The laser displacement sensors are used to measure the diameter of the workpiece placed inside the correction components.

[0037] In some preferred embodiments, the workpiece is housed within the receiving openings of the two correction components 1, and the workpiece has a receiving gap within the inner wall of the receiving opening, allowing the workpiece to have space for dynamic adjustment within the receiving opening. This application abandons the traditional method of clamping the workpiece to the correction component for measurement, and instead adopts a method of placing the workpiece within the receiving opening for dynamic measurement. This is because, in the clamping and fixed measurement mode, when the workpiece is clamped on the correction component, the clamping force exerts an effect on the workpiece. For workpieces with thin walls, soft materials, or low structural strength, this can easily cause local deformation. For example, when measuring plastic pipes, the clamping pressure may cause local flattening, resulting in a deviation between the measured diameter and the actual diameter, failing to accurately reflect the workpiece size. In dynamic measurement, the workpiece is in a naturally placed state, without bearing additional clamping force, maintaining its original shape and structure, making the measurement data more accurately reflect the actual diameter of the pipe, greatly improving measurement accuracy and reliability. In addition, when the worktable vibrates during clamping and fixed measurement, the vibration will be directly transmitted to the workpiece through the correction component. Due to the rigid connection, the vibration amplitude of the workpiece is amplified, interfering with the measurement results. During dynamic measurement, there is a gap between the workpiece and the receiving port, which can effectively reduce vibration transmission and reduce the vibration amplitude of the workpiece.

[0038] Specifically, such as Figure 2As shown, the correction assembly 1 includes a support frame 11 and support blocks 12. The top center of the support frame 11 has a U-shaped opening that runs through the X-axis. There are two support blocks 12. One end of each support block 12 is hinged to the two sides of the top of the support frame 11 and is arranged opposite each other along the Y-axis. The other end of each support block 12 has an opening slot that runs through the X-axis. When both support blocks 12 rotate to the U-shaped opening of the support frame 11, the opening slots of the two support blocks 12 abut against each other to form a receiving opening for receiving the workpiece.

[0039] In some preferred embodiments, the lower part of the receiving port of the correction component 1 is V-shaped, and the two inclined surfaces of the clamping port of the V-shape are symmetrical. When the workpiece is placed in, the outer wall of the workpiece will simultaneously contact the two inclined surfaces of the V-shape of the receiving port. Due to the effect of the inclined surfaces, the workpiece will automatically move towards the center position of the V-shape under the action of gravity or slight external force until it reaches a balanced state, thereby achieving rapid and accurate positioning at the center position of the receiving port.

[0040] In some preferred embodiments, although the laser displacement sensor has high sensitivity to workpiece surface measurements, slight installation deviations can still lead to significant measurement errors. While the lead screw compound drive can reduce workpiece clamping vibration to some extent, there are many uncontrollable factors in the factory environment, such as equipment vibration and airflow disturbances. These factors may cause the correction assembly to vibrate, which in turn causes the workpiece within its receiving opening to vibrate. Once the workpiece shakes within the receiving opening, the laser displacement sensor's detection results will be inaccurate, affecting the system's control accuracy and stability.

[0041] In addition to the influence of dynamic vibration factors, the measurement position of the workpiece in the laser displacement sensor will also affect the measurement results. Each set of laser displacement sensors consists of a transmitter and a receiver, which are used to emit parallel light and collect the diffracted beam image formed after being blocked by the object being measured. The intersection of the perpendicular rays of the two sets of laser displacement sensors constitutes the detection center. When the workpiece being measured is located at this detection center, the measurement results can achieve the best accuracy. In order to improve the accuracy of the measurement results, it is necessary to correct the position of the workpiece so that the workpiece in the receiving port is always located near the detection center.

[0042] Therefore, within the receiving port of the correction component, the difference in vertical distance between the workpiece's outer surface and the closest point between the transmitter and receiver of the same set of laser displacement sensors is defined as the offset. Set the offset Within the threshold range, the correction component 1 is connected to a displacement driving component 3. The displacement driving component 3 is electrically connected to the laser displacement sensor via a control device 4. The control device controls the displacement driving component 3 to drive the correction component 1 to perform Z-axis and Y-axis displacement correction until it is adjusted to the offset of each group of laser displacement sensors. Within its threshold range, the laser displacement sensor measures the diameter of the workpiece tube after correction to ensure measurement accuracy.

[0043] In some preferred embodiments, the receiving port of the correction component 1 is located at its top, and its bottom is connected to the displacement driving component 3. The displacement driving component 3 includes a first displacement driving component 31 arranged along the Z direction and a second displacement driving component 32 arranged along the Y direction. The bottom of the correction component 1 is connected to the output end of the first displacement driving component 31, and the first displacement driving component 31 is connected to the output end of the second displacement driving component 32. Preferably, the first displacement driving component 31 and the second displacement driving component 32 are a lead screw composite drive, which has the advantages of accurate positioning and smooth movement.

[0044] Specifically, such as Figure 2 As shown, the first displacement driving component 31 includes a first support frame 311, a first lead screw 312, a first motor 313, and a first nut 314. The first lead screw 312 is rotatably disposed in the first support frame 311 along the Z direction. The first motor 313 is fixedly connected to the first support frame 311, and the output end of the first motor 313 is connected to the first lead screw 312. The first nut 314 is slidably connected to one side of the first support frame 311 along the Z direction and is threadedly connected to the first lead screw 312. The first lead screw 312 is fixedly connected to the correction component 1. Under the driving action of the first motor 313, the first lead screw 312 rotates, thereby driving the first nut 314 and the correction component 1 to move back to the Z direction.

[0045] In some preferred embodiments, the second displacement drive component 32 has the same structure as the first displacement drive component 31, except that the lead screw of the second displacement drive component 32 is arranged along the Y direction. The specific structure will not be described in detail here.

[0046] In some preferred embodiments, the rays emitted from the ray ends of the first laser displacement sensor group L1-L1' and the second laser displacement sensor group L2-L2' are each at a 45° angle to the horizontal plane, which is used to expand the measurement range of the sensors, improve the measurement accuracy, and enable them to meet the measurement requirements of dynamic workpieces.

[0047] In some preferred embodiments, such as Figure 3 As shown, the first laser displacement sensor group L1-L1' and the second laser displacement sensor group L2-L2' are integrated in the frame 6. The frame 6 includes a frame body 61. A square opening 60 is provided in the middle of the frame body 61 along the X-axis. The diagonals of the square opening 60 intersect along the Z-axis and Y-axis. The top of the square opening 60 is open to facilitate the placement of workpieces from top to bottom.

[0048] In some preferred embodiments, the frame 61 is provided with a plurality of limiting protrusions 611, which are arranged along the periphery of the square opening 60. The four walls of the square opening 60 are respectively provided with mounting notches 612, and the sensing head of the laser displacement sensor is installed at the mounting notch 612. The sensing head is located between the wall of the frame 61 and the adjacent limiting protrusion 611. A laser window 62 is connected to the mounting notch 612. The laser window 62 is used to transmit the rays of the sensing head and block dust.

[0049] To facilitate understanding, this application provides an explanation of the specific measurement and compensation process:

[0050] In some preferred embodiments, the offset The following steps were used to arrive at the following conclusions:

[0051] In some preferred embodiments, the offset The following steps were used to arrive at the following conclusions:

[0052] First, obtain two sets of one-dimensional pixel sequences:

[0053] The one-dimensional pixel sequence obtained by the L1-L1' group is ;

[0054] The one-dimensional pixel sequence obtained by the L2-L2' group is ;

[0055] Where n is the pixel sequence length, which depends on the sensor resolution.

[0056] Then, edge detection and position calculation:

[0057] This step precisely determines the object's edge position using convolution operations and parabolic fitting, employing convolution kernels. Convolutional processing of sequence Y yields a rate-of-change sequence C, where each element ci is the dot product of the convolution kernel and the corresponding subsequence in the signal.

[0058] ,in, ;

[0059] In sequence C, find local maxima points, which correspond to the locations with the largest changes in pixel values, i.e., the initial edge points of the object. For each initial edge point, extract its three surrounding points and perform parabolic fitting:

[0060] ;

[0061] By solving the coordinates of the vertex of the parabola This allows us to obtain precise edge positions.

[0062] Within the same group of laser displacement sensors, the edge position of the laser displacement receiving end can be used for measurement. There are two edge positions for the laser displacement sensor receiving end: the upper edge and the lower edge. The upper edge position can be determined by the vertical distance from the closest point on the upper edge of the workpiece's outer surface to the upper edge of the sensor receiving end. Figure 4 The lower edge position of D1, as indicated in the diagram, can be determined by the vertical distance from the lowest point between the lower edge of the workpiece's outer surface and the lower edge of the sensor's receiving end. Figure 4 D2, as indicated in the middle, is determined.

[0063] The same method is used to process sequence Z to obtain the corresponding edge distance.

[0064] Finally, the offset is calculated based on the edge detection results of the L2-L2´ group. :

[0065] ;

[0066] in, Positive values ​​indicate upward offset, while negative values ​​indicate downward offset.

[0067] It should be added that a through-beam laser displacement sensor consists of a transmitter and a receiver. Its working principle is as follows: the transmitter emits a laser beam, and the receiver receives the reflected light. The receiver converts the received reflected light signal into an electrical signal, which is then processed to obtain waveform data composed of a sequence of pixels. The waveform has obvious peaks, corresponding to the surface features of the target object. When performing offset measurement, these pixel sequences are used. The sensor receiver typically has a fixed measurement range or field of view; its upper and lower edges define the effective area for receiving reflected light. The upper outer surface of the workpiece corresponds to a rising edge or peak region in the waveform diagram. It is the vertical distance from the top of this rising edge (i.e., the point on the outer surface of the workpiece that is closest to the upper edge of the sensor receiver) to the upper edge of the sensor receiver. This distance reflects the position of the upper edge of the workpiece relative to the upper edge of the sensor receiver and can be used to calculate the offset of the workpiece in the vertical direction.

[0068] In some preferred embodiments, the offsets of the first laser displacement sensor group and the second laser displacement sensor group are compared. The magnitude of the value, in terms of offset Real-time offset continuously collected by a group of laser displacement sensors with large numerical deviations A linear prediction model is established for the reference value. This model analyzes the offset at the current time. Estimate the workpiece position offset in the next control cycle to obtain the offset prediction value. The control device 4 obtains the offset prediction value. As the displacement correction compensation amount of displacement driving component 3 These are important parameters, which in turn drive the first correction component 1 and / or the second correction component 2 to pre-synchronize displacement and correct deviations before the workpiece position changes.

[0069] Preferably, the offset of the first set of laser displacement sensors L1-L1´ is used. Using this as a reference, the workpiece is adjusted to the center of the detection plane, and the real-time offset is continuously collected by the second laser displacement sensor group L2-L2´. A linear prediction model is established for the reference value.

[0070] In some preferred embodiments, according to The changing trend was predicted by using polynomial fitting, linear regression model, Kalman filter and autoregressive model AR(1) respectively, and the model was constructed.

[0071] In some preferred embodiments, before constructing the linear prediction model, it is also necessary to process the continuously collected real-time offsets. The values ​​are preprocessed, for example, by sliding window filtering, to eliminate vibration and noise interference.

[0072] Take the polynomial fitting model as an example;

[0073] First, the filtered offset data sequence and the corresponding time series Pair them up to form a training dataset.

[0074] Then, based on the training dataset, the coefficients of the polynomial are determined using the least squares method to construct a polynomial fitting model. Specifically, let the order of the polynomial be n, and the constructed polynomial function is:

[0075] ;

[0076] in, This is the predicted offset value at time t obtained based on polynomial fitting. These are the polynomial coefficients.

[0077] The goal of least squares is to minimize the predicted value. Compared with the actual filtered offset value The sum of squared errors between them, (where, (where m is the number of data points in the training dataset), and its objective function is:

[0078] ;

[0079] By taking the partial derivative of the objective function S with respect to the coefficients ai, and setting the partial derivative to 0, we can obtain... Solving this system of equations yields the optimal polynomial coefficients ai, thus completing the construction of the polynomial fitting model. Using this model, the corresponding offset can be predicted based on future time points. This provides a basis for subsequent decision-making and control.

[0080] when Offset Outside the threshold range, the control device 4 drives the displacement drive component 3 to drive the first correction component 1 and the second correction component 2 to synchronously correct the displacement.

[0081] In some preferred embodiments, the offset The value is the sequence point value, which is usually displayed in the hundreds place. However, the actual displacement adjustment required by the displacement drive component is very small, only requiring a single-digit millimeter level. Therefore, the offset also needs to be adjusted. The sequence point values ​​are obtained through the scaling factor. Converted to displacement compensation amount Preferred, proportional coefficient It can be obtained through data simulation, and the value is usually between 0.1 and 0.2.

[0082] In some preferred embodiments, although the control system can acquire the offset data from the laser displacement sensor in real time and generate control commands, there is a significant motion delay (including mechanical transmission lag and load inertia response) between the displacement drive components (such as servo motors, ball screws, etc.) receiving the command and completing the precise positioning of the correction components. This delay causes a time deviation between the actual displacement compensation and the theoretical requirement, therefore, a proportional coefficient is also needed. The design incorporates a dynamic time compensation mechanism, and the specific optimization scheme is as follows:

[0083] Let the actual motion time of the drive component be Td (Unit: ms), which includes inherent attributes such as transmission delay and motor acceleration / deceleration time. When the controller predicts the current offset value... Calculate displacement correction compensation amount ,Right now = At that time, it is necessary to anticipate Td Real-time offset trend of the workpiece within a time period to avoid over- or under-compensation due to delay.

[0084] Will The compensation factor has been upgraded from a fixed parameter to one that dynamically adjusts with the delay time. ,in ， The basic proportional coefficient, This is a correction function based on driving characteristics.

[0085] Let the speed of the driving component be... If the motion is constant (or approximately uniform), then the displacement compensation amount needs to be calculated in advance. Td The time calculation formula is corrected as follows:

[0086] ;

[0087] in, The amount of displacement compensation needs to be calculated in advance. The control period (sensor sampling period) is used to quantify the impact of delay time on compensation accuracy. The system needs to be determined through preliminary calibration experiments to ensure system stability without delay (e.g., by obtaining the critical proportional coefficient through step response testing, which is related to parameters such as workpiece mass, transmission accuracy of displacement drive components, and system inertia; the preferred coefficient is...). The value range is 0.5-1.2.

[0088] In some preferred embodiments, the rays emitted from the ray ends of the first laser displacement sensor group L1-L1' and the second laser displacement sensor group L2-L2' are each at a 45° angle to the horizontal plane, which is used to expand the measurement range of the sensors, improve the measurement accuracy, and enable them to meet the measurement requirements of dynamic workpieces.

[0089] In some preferred embodiments, when the laser displacement sensor is arranged obliquely, based on the acquired displacement correction compensation amount... Since this is one-dimensional data, to accurately adapt to the needs of multi-axis control, the displacement correction compensation amount needs to be calculated. Perform a vector decomposition operation to break it down into displacement components along the Z and Y axes.

[0090] In some preferred embodiments, the origin O is taken as the intersection of the rays of two vertically arranged through-beam laser displacement sensors, and a reference line is formed by extending along the X-axis. The horizontal direction perpendicular to the X-axis is the Y-axis, and the vertical direction perpendicular to the X-axis is the Z-axis. A rectangular coordinate system O-XYZ is established on this reference line.

[0091] When the system obtains the displacement correction compensation amount through the prediction model Then, it is decomposed into vectors along the Y and Z axes, where, This represents the component of the displacement compensation in the Y-axis direction. To obtain the displacement compensation component along the Z-axis, the decomposed vector components are reversed to obtain the reverse vector. = , = - Reverse the Y-axis component As the displacement compensation amount of the second displacement drive component 32, the Z-axis reverse component is... The displacement compensation amount is used as the first displacement driving component 31.

[0092] In some preferred embodiments, this application also provides an adaptive adjustment method for a laser displacement feedback-based correction device, comprising the following steps:

[0093] S1, the vertical distance difference between the workpiece within the receiving port of the correction component and the closest point between the outer surface of the same set of laser displacement sensors and the two edges of its receiving end is defined as the offset. Define the offset The threshold;

[0094] S2, the first laser displacement sensor group L1-L1' and the second laser displacement sensor group L2-L2' measure the offset in real time respectively. ;

[0095] S3, compare the offsets of the first laser displacement sensor group and the second laser displacement sensor group. The magnitude of the value, in terms of offset Offset of a group of laser displacement sensors with large numerical deviations A linear prediction model is established based on the reference value to estimate the workpiece position offset in the next control cycle, thereby obtaining the offset prediction value. ,

[0096] S4, Compare the offset prediction values and offset The magnitude of the value, when comparing the offset predicted value Exceeding the offset Within the threshold range, perform correction actions when comparing the predicted offset values. Not exceeding the offset If the threshold range is exceeded, no corrective action will be performed.

[0097] In some preferred embodiments, when comparing offset prediction values Exceeding the offset Within the threshold range, when performing corrective actions, the following steps are included:

[0098] S41, based on the current offset prediction value Calculate displacement correction compensation amount ;

[0099] S42, the displacement correction compensation amount Decomposed into displacement components along the Z-axis and Y-axis, the Z-axis vector displacement component is obtained. Y-axis vector displacement components ;

[0100] S43, reverse the decomposed vector displacement to obtain the Y-axis reverse vector displacement compensation. , = - Z-axis reverse vector displacement compensation amount , = - ;

[0101] S44, Control device 4 compensates for Z-axis reverse vector displacement. The first displacement drive component 31 completes the Z-axis displacement along the Z-axis according to its vector direction, and the displacement compensation amount is based on the reverse vector displacement. The second displacement drive component 32 is driven to complete the Y-axis displacement along the Y-axis in its vector direction.

[0102] In some preferred embodiments, during the correction process, the laser displacement sensor continuously measures the diameter D of the workpiece, which is derived from the following formula.

[0103] ;

[0104] Where L is the total length of the field of view of the laser displacement sensor. The vertical distance from the upper edge of the workpiece's outer surface to the nearest point on the upper edge of the sensor receiver, and the distance from the lower edge. It is the vertical distance from the lowest point on the lower edge of the workpiece's outer surface to the lowest point on the lower edge of the sensor's receiving end.

[0105] The following is a detailed description of the steps involved in measuring the diameter D of the workpiece:

[0106] S51, Sequence Correction Length Calculation:

[0107] According to the formula Calculate adjustment length ,in For real-time offset, and These are fixed coefficients, obtained by fitting the pixel sequence error of the same object at different offsets in the L2-L2´ group to the corresponding pixel sequence error in the L1-L1´ group. ;

[0108] S52, Pixel Sequence Correction:

[0109] when At that time, local deletion is performed on the original L1-L1´ pixel sequence, with the deletion starting at the... End position And use cubic spline interpolation to generate supplementary points at both ends of the sequence so that the length of the corrected pixel sequence Y´ is the same as that of the original pixel sequence;

[0110] when At that time, cubic spline interpolation is used to generate [a new pixel array] on both sides of the original pixel sequence. Add one point and delete the same number of points at both ends of the sequence to make the length of the corrected pixel sequence Y´ the same as the original pixel sequence;

[0111] S53, Edge Detection and Position Calculation:

[0112] Use convolution kernel The corrected pixel sequence Y' is convolved to obtain the rate of change sequence C, where, ;

[0113] Find local maxima in sequence C as initial edge points, and perform parabolic fitting on three points around each initial edge point. And by solving the coordinates of the vertex of the parabola Obtain the precise edge position;

[0114] Determine the vertical distance from the nearest point on the upper edge of the workpiece's outer surface to the upper edge of the sensor. And the vertical distance from the lower edge of the workpiece's outer surface to the nearest point on the lower edge of the sensor. ;

[0115] S54, diameter D calculation:

[0116] According to the formula Calculate the workpiece diameter D.

[0117] To facilitate understanding, this application provides an example illustrating the measurement process of the workpiece diameter D:

[0118] The workpiece is placed within the receiving openings of the first correction assembly 1 and the second correction assembly 2. The first laser displacement sensor group L1-L1' acquires the contour features of the workpiece to obtain the following... Figure 5 The pixel sequence diagram shown is obtained by the second laser displacement sensor group L2-L2´ acquiring the contour features of the workpiece. Figure 6 The pixel sequence image shown is composed of... Figure 5 , Figure 6 The comparison shows that, although Figure 5 The workpiece shown in the image is located in the middle of the field of view acquired by the first laser displacement sensor group L1-L1', but in reality, it is located in the middle of the field of view acquired by the laser displacement sensor group L1-L1'. Figure 6As can be seen, the workpiece deviates from the central position region in the field of view of the second laser displacement sensor group L2-L2'. Therefore, the workpiece diameter D obtained by the first laser displacement sensor group L1-L1' is 367.31-145.36 = 221.95 according to the pixel sequence acquired by the second laser displacement sensor group L2-L2'. The value is 512 - 279.93 = 232.07. It is 75.18. =232.07 - 75.18 = 156.89, diameter D = 204.75. The difference between the two sets of data is large, indicating that the workpiece diameter obtained by the first laser displacement sensor group L1-L1´ is a pseudo diameter and not an accurate value.

[0119] At this point, although the deviation has already occurred, the displacement drive component cannot correct the data already collected. It can only intervene when the predicted position continues to deviate in the later stages. However, at this point, the data collection error has already occurred. In order to avoid inaccurate data collection, the first laser displacement sensor group L1-L1' will correct its pixel sequence based on the pixel sequence of the second laser displacement sensor group L2-L2'.

[0120] Specifically, based on the deviation Calculate the adjustment length When k>0, perform local deletion on the original L1-L1´ pixel sequence, starting at the deletion position. End position And, using cubic spline interpolation at both ends of the sequence, supplementary points are generated to make the length of the corrected pixel sequence Y´ consistent with that of the original pixel sequence. This involves local deletion of the original pixel sequence, with supplementary points generated at both ends. The deletion starts at point 248. Figure 7 As shown, the gray area represents the deleted portion, and the green and purple areas at both ends represent the generated replacement points, resulting in the final product as shown. Figure 8 The pixel sequence image shown is based on Figure 8 As shown in the pixel sequence diagram, the diameter .

[0121] At the same time, define the offset The threshold range is less than 3 when comparing the offset predicted values. It will exceed the offset. When the threshold range is reached, the displacement driving component 3 drives the first correction component 1 and the second correction component 2 to perform displacement correction. This means that at any future moment, although there may be a positional deviation, the workpiece will be adjusted to the center area within the detection plane of the laser displacement sensor through the displacement of the correction components. After this, at any subsequent moment, the diameter D is calculated using a pixel sequence image acquired at a certain moment. Figure 9 As shown, the distance from the top edge The distance from the bottom edge is 512 – 355.88 = 156.12. It is 154.59. The distance between the top and bottom edges is less than the offset. The threshold range can be considered to be in the exact middle, with diameter D = 355.88 - 154.59 = 201.29. Therefore, the workpiece diameter D calculated after workpiece position adjustment is essentially equal to the workpiece diameter D obtained after image sequence correction, effectively ensuring the accuracy of the measurement results.

[0122] The specific embodiments of this application have been described in detail above. For those skilled in the art, several improvements and modifications can be made to this application without departing from the principle of this application, and these improvements and modifications also fall within the protection scope of the claims of this application.

Claims

1. A correction device based on laser displacement feedback, characterized in that: It includes two through-beam laser displacement sensors arranged in a vertical direction, namely a first laser displacement sensor group (L1-L1') and a second laser displacement sensor group (L2-L2'). The detection plane constructed by the vertical laser displacement sensors is defined as the X-axis direction. Correction components (1) are respectively arranged along the X-axis direction on both sides of the laser displacement sensors. The line connecting the centers of the receiving ports of the correction components (1) on both sides extends along the X-axis direction into the detection plane of the laser displacement sensors. The correction component (1) is connected to the displacement drive component (3). The displacement drive component (3) is electrically connected to the laser displacement sensor through the control device (4). The control device (4) controls the displacement drive component (3) to drive the center line of the accommodating port of the correction component (1) and the second correction component (2) to be aligned in the detection plane for displacement correction.

2. The correction device based on laser displacement feedback according to claim 1, characterized in that: Using the bottom plane of the correction component as a horizontal reference, the direction perpendicular to the preset X-axis and within the horizontal plane is defined as the Y-axis direction. The correction component (1) includes a support frame (11) and a support block (12). The top center of the support frame (11) has a U-shaped opening that runs through the X-axis. There are two support blocks (12). One end of each support block (12) is hinged to the two sides of the top of the support frame (11) and they are arranged opposite each other along the Y-axis. The other end of each support block (12) has an opening slot that runs through the X-axis. When both support blocks (12) rotate to the U-shaped opening of the support frame (11), the opening slots of the two support blocks (12) abut against each other to form a receiving opening.

3. The correction device based on laser displacement feedback according to claim 2, characterized in that: The lower part of the receiving opening is V-shaped, and the two inclined surfaces of the V-shaped receiving opening are symmetrical.

4. The correction device based on laser displacement feedback according to claim 1, characterized in that: Using the bottom plane of the correction component (1) as the horizontal reference, the direction perpendicular to the preset X-axis and within the horizontal plane is defined as the Y-axis direction, and the direction perpendicular to the X-axis and Y-axis and perpendicular to the horizontal plane upward is defined as the Z-axis direction. The displacement drive component (3) includes a first displacement drive component (31) arranged along the Z-axis direction and a second displacement drive component (32) arranged along the Y-axis direction. The bottom of the correction component is connected to the output end of the first displacement drive component (31), and the first displacement drive component (31) is connected to the output end of the second displacement drive component (32).

5. The correction device based on laser displacement feedback according to claim 4, characterized in that: The first displacement drive assembly (31) and the second displacement drive assembly (32) are screw-driven composite drives. The first displacement drive assembly (31) includes a first support frame (311), a first screw (312), a first motor (313), and a first nut (314). The first screw (312) is rotatably disposed in the first support frame (311) along the Z direction. The first motor (313) is fixedly connected to the first support frame (311), and the output end of the first motor (313) is connected to the first screw (312). The first nut (314) is slidably connected to one side of the first support frame (311) along the Z direction and is threadedly connected to the first screw (312). The first screw (312) is fixedly connected to the correction assembly (1).

6. The correction device based on laser displacement feedback according to claim 4, characterized in that: The rays emitted from the ray ends of the first laser displacement sensor group (L1-L1´) and the second laser displacement sensor group (L2-L2´) each form a 45° angle with the horizontal plane.

7. The correction device based on laser displacement feedback according to claim 6, characterized in that: The first laser displacement sensor group (L1-L1´) and the second laser displacement sensor group (L2-L2´) are integrated in the frame (6). The frame (6) includes a frame body (61). A square opening (60) is provided in the middle of the frame body (61) along the X-axis. The diagonals of the square opening (60) intersect along the Z-axis and Y-axis. The top of the square opening (60) is open.

8. The correction device based on laser displacement feedback according to claim 7, characterized in that: The frame (61) is provided with a plurality of limiting protrusions (611), which are distributed around the periphery of the square opening (60). The four walls of the square opening (60) are respectively provided with mounting notches (612), and the sensing head of the laser sensor is installed at the mounting notch (612). The sensing head is limited between the wall of the frame (61) and the adjacent limiting protrusions (611).

9. The correction device based on laser displacement feedback according to claim 8, characterized in that: A laser window (62) is connected to the mounting notch (612).

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