A three-dimensional printing quality compensation method and system based on height information
By establishing a functional relationship between extrusion height and printing extrusion amount and implementing real-time measurement compensation, the problem of inaccurate Z-axis positioning in 3D printers was solved, achieving low-cost, high-precision 3D printing results.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- MOXIN (HUZHOU) TECH CO LTD
- Filing Date
- 2022-09-21
- Publication Date
- 2026-07-21
AI Technical Summary
The Z-axis precision of existing 3D printers is not high, which affects the printing quality. In particular, there is heat loss and step loss during Z-axis positioning, making it difficult to achieve precise layer height control.
By establishing a functional relationship between extrusion height and printing extrusion volume during the pre-calibration stage, the printing height is measured in real time using a height measurement component and compensation is performed. Combined with neural networks and digital image association algorithms, the printing flow rate is adjusted to achieve precise layer height control.
It achieves low-cost, high-precision 3D printing, solves the printing quality problem caused by inaccurate Z-axis positioning in existing technologies, reduces equipment costs, and improves printing accuracy.
Smart Images
Figure CN115742313B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of 3D printing, and in particular to a 3D printing quality compensation method and system based on height information. Background Technology
[0002] 3D printers using Fused Deposition Modeling (FDM / FFF) technology are widely used in various fields such as prototype processing, education, and toys, thanks to their low cost and ease of use. A crucial factor determining the accuracy of 3D printing is the Z-axis positioning. Accurate Z-axis positioning allows for smooth and stable lamination and movement within the XY plane. Conversely, since the print flow rate is pre-calculated based on the layer height, errors in the layer height can lead to a mismatch between the print flow rate and the layer height, potentially resulting in over-extrusion or under-extrusion. The former affects the dimensional accuracy of the printed content, while the latter affects the strength of the printed content and can even directly cause layers to fail to adhere, resulting in printing failure. Current research optimizes the mechanical structure design of 3D printers. For example, Chinese patent CN103831975A discloses a dual-screw, dual-optical-axis drive mechanism to achieve smoother driving and higher printing accuracy. However, the Z-axis mass of 3D printers is typically large, making precise positioning challenging. The high current applied by the stepper motor when driving large objects can cause the system to overheat during prolonged operation, potentially leading to missed steps.
[0003] Therefore, a method is needed to detect the printing layer height and compensate accordingly in the Z-axis direction to solve the problem of low Z-axis accuracy in existing 3D printers affecting printing quality. Summary of the Invention
[0004] To achieve the above objectives, the present invention provides the following technical solution:
[0005] This invention provides a 3D printing quality compensation method based on height information, the compensation method comprising:
[0006] (1) In the pre-calibration stage, the extrusion height hp and the corresponding printing extrusion amount Fi are fitted to obtain the functional relationship of the theoretical basic height hp(Fi,θ), where θ is the set of other parameters that are identified to affect the printing height;
[0007] (2) The three-dimensional model is converted into motion instructions by a preset slicing software, including the extrusion amount Fi of the print head at each position. Preferably, the motion instructions are instructions used to control when the printer print head goes where.
[0008] (3) After each layer is printed, the height value hj of the actual printed content in that layer is measured using the height measurement component, and the print flow correction value Fpi is calculated to obtain the expected height to be achieved in the next layer. Then, the print flow correction value Fpi is used to continue printing in the next layer.
[0009] Furthermore, in step (1), the method for obtaining the theoretically based functional relationship hp(Fi,θ) during the calibration process is as follows:
[0010] The 3D printer's control board controls the print head's extrusion volume Fi. One or more of the following height-measuring components—LiDAR, laser rangefinder, and ultrasonic sensor—are used to measure the pre-set extrusion height hp corresponding to the extrusion volume. Based on the measurement, a neural network algorithm or least squares method is used to fit a function between the extrusion height hp and the print extrusion volume Fi, where θ represents the set of other parameters identified that affect the print height. The printer's control board adjusts the motor speed or pump pressure in the nozzle responsible for the extrusion section to regulate the extrusion volume.
[0011] (11) Collect the preset height value within the preset height range on the workpiece to be measured, and move the preset distance in the X or Y direction by the motion mechanism of the height measuring component at each height value;
[0012] (12) Obtain the pattern of each reflected light by the photoelectric signal acquisition array, and process it by the digital image association algorithm to obtain the distance the pattern moves;
[0013] (13) By fitting a preset function to the height value and the distance the pattern moves, the functional relationship of the preset height value is obtained;
[0014] (14) The height measuring component moves in the X or Y direction by a preset external positioning platform, and the corresponding height value is read.
[0015] (15) Determine whether the read height value is within the height range. If not, output the error height.
[0016] (16) The average value of the height value is obtained by using the functional relationship of the height value. The average value is the extrusion height hp.
[0017] Further, the specific steps of step (3) are as follows: the three-axis motion mechanism drives the print head and the height measuring component. The height measuring component passes through the area of the part of the layer that has been printed and records the height value hj of the actual printed content in the layer. The difference h between the height value hj of the actual printed content in the layer and the ideal printing height value hi is calculated through the print file. 差 The difference value h 差By supplementing the flow using the theoretically based functional relationship hp(Fi,θ), the expected print flow correction value Fpi for the next layer should be calculated.
[0018] Furthermore, in step (3), if the difference between the actual printed height hj and the ideal printed height hi is h... 差 If the value is greater than or equal to the preset threshold ht, output a failure result and stop printing.
[0019] Preferably, the preset threshold ht is a set safety limit that is determined based on the range of the printer's extrusion flow rate. The printer's extrusion flow rate has a range; the larger the flow rate, the higher the height. However, if the height is too high, the printer cannot extrude that much flow rate, so it outputs a failure result and stops printing.
[0020] Furthermore, the height measurement component includes a photoelectric signal acquisition array, a light source, a lens, and a processing unit. The light source is located on one side of the photoelectric signal acquisition array. The light emitted by the light source illuminates the plane being measured. A portion of the light reflected by the plane being measured is received by the photoelectric signal acquisition array to obtain an electrical signal. The electrical signal is processed by the processing unit to obtain height information.
[0021] Furthermore, the height measuring component and the print head are fixedly connected, the height measuring component moves with the print head, or both the print head and the height measuring component are always fixed, or the height measuring component is fixed on the printer frame and the print head moves relative to it; at least one height measuring component is disposed on one side of the print head.
[0022] The present invention also provides a 3D printing quality compensation system based on height information, the system comprising:
[0023] Height measuring component, used to measure the printed height;
[0024] The first function construction module is used to establish the functional relationship hp(Fi,θ) of the theoretical basic height based on the printing extrusion amount Fi and the extrusion height hp, where θ is the set of other parameters that are identified to affect the printing height;
[0025] The conversion module is used to convert the 3D model into motion instructions through preset slicing software, including the extrusion amount Fi of the print head at each position.
[0026] The acquisition module is used to acquire a preset number of height values within a preset height range on the workpiece to be measured. By acquiring the preset number of height values within the preset height range on the workpiece to be measured, the motion mechanism of the height measuring component is driven to move a preset distance in the X or Y direction at each height value. During the movement, the photoelectric signal acquisition array records the preset patterns of each reflected light.
[0027] The data processing module is used to obtain the distance the pattern has moved, which is obtained through digital image association algorithms;
[0028] The second function construction module is used to construct the functional relationship of height values, which is obtained by fitting a preset function to the height values and the distance the pattern moves.
[0029] This invention establishes a functional relationship for height values during the pre-calibration stage through a function module. This solves the problem of positional interference between the contact switch installed on the machining actuator or fixed frame and the machining head and workpiece. Based on the characteristic that the signal received by the photoelectric signal acquisition array and the DIC algorithm differ when the positioning component moves the same distance at different heights, a functional relationship is established during the pre-calibration stage. This functional relationship is then used for repeatable height measurement, solving the problems of high cost and low accuracy in existing technologies.
[0030] The reading module is used to preset the movement distance of the external positioning platform control height measuring component in the X or Y direction and read the corresponding height value;
[0031] The compensation module is used to calculate the print flow correction value Fpi for the expected height that the next layer should achieve;
[0032] The analysis and judgment module is used to determine whether the read corresponding height value is within the height range. If not, it outputs an error height.
[0033] The output module is used to obtain the average value as the output result by reading the corresponding height value and using the functional relationship of the height value.
[0034] Furthermore, the compensation module, after each layer is printed, drives the printhead and height measuring component via a three-axis motion mechanism. The height measuring component passes through the area where the layer has been printed and records the actual height value hj of the printed content within that layer. The difference h between the actual height value hj and the ideal height hi is calculated using the printed file. 差 The difference value h 差 The expected print flow correction value Fpi for the next layer is calculated based on the theoretical functional relationship hp(Fi,θ). This correction value is then used for printing at the next layer. If hj-hi=>ht, a failure result is output and printing stops, where ht is a preset threshold.
[0035] Furthermore, the height measurement component includes a photoelectric signal acquisition array, a light source, a lens, and a processing unit. The light source is located on one side of the photoelectric signal acquisition array. The light emitted by the light source illuminates the plane being measured. A portion of the light reflected by the plane being measured is received by the photoelectric signal acquisition array to obtain an electrical signal. The electrical signal is processed by the processing unit to obtain height information.
[0036] The present invention has the following beneficial effects:
[0037] (1) The present invention uses a non-contact height sensing component fixed on one side of the printing nozzle to control three-dimensional printing through height information, thereby achieving three-dimensional printing with low printing cost and high precision.
[0038] (2) Based on the characteristic that the results obtained by the DIC algorithm from the signal received by the photoelectric signal acquisition array when the positioning component moves the same distance at different heights are different, the present invention constructs a functional relationship in the pre-calibration stage of product production and uses this functional relationship to perform repeatable height measurement, thus solving the problems of high cost and low accuracy of the existing technology.
[0039] (3) The present invention constructs a functional relationship of height value in the pre-calibration stage through a function module, which solves the problem that the contact switch installed on the machining actuator or fixed frame is prone to position interference with the machining head and workpiece of the machining actuator;
[0040] (4) The present invention compensates for the printed content based on the measured printing height, which solves the main problem of height error that causes deviation of printed content. It has lower cost and higher accuracy than machine vision methods using depth cameras or high-definition cameras for shape compensation (the compensation accuracy of using high-definition cameras is limited by the camera resolution and camera intrinsic parameters such as distortion calibration). Attached Figure Description
[0041] Figure 1 This is a flowchart of the compensation method in Example 1.
[0042] Figure 2 This is a flowchart of the process for obtaining hp(Fi,θ) in Example 1.
[0043] Figure 3 This is a schematic diagram of the height measuring component in Example 1.
[0044] Figure 4 This is a system module diagram of Embodiment 2. Detailed Implementation
[0045] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be noted that the embodiments are only specific illustrations of the invention and should not be regarded as limitations on the invention. The purpose of the embodiments is to enable those skilled in the art to better understand and reproduce the technical solution of the present invention. The scope of protection of the present invention should still be determined by the scope defined in the claims.
[0046] Example 1
[0047] like Figure 1As shown, this embodiment provides a 3D printing quality compensation method based on height information, the compensation method including:
[0048] S1, In the pre-calibration stage, the extrusion height hp and the corresponding printing extrusion amount Fi are fitted to obtain the functional relationship hp(Fi,θ) of the theoretical basic height, where θ is the set of other parameters that are identified to affect the printing height;
[0049] like Figure 2 As shown, the method for obtaining hp(Fi,θ) during the calibration process is as follows:
[0050] S11. Within a height range [h0-hn], n height values are preset, namely {h0, h1, h2, ... hn} (n>1, n is a positive integer). The preset height values within the preset height range [h0-hn] on the workpiece to be measured are collected. At each height value, the motion mechanism of the height measuring component drives the movement distance in the X or Y direction, and the movement distance is {L0, L1, L2...Lm} (m>=0, m is a positive integer). The height values can be sampled at equal intervals or randomly.
[0051] A series of preset heights and a series of moving distances in the X or Y direction are collected using other sensors. Then, the pattern moving distance is obtained using a digital correlation algorithm, based on the functional relationship between the moving distance in the X or Y direction and the pattern moving distance.
[0052] The specific steps for obtaining the extrusion height hp are as follows: A1: On the test plane of the component to be tested, the height measuring component is driven to move on the coordinate axis of the CNC equipment by a preset positioning mechanism to obtain the preset moving distance corresponding to each movement; During each movement, the photoelectric signal acquisition array is used to acquire the reflected light patterns of several test planes, and the distance between adjacent reflected light patterns is obtained through the processing unit.
[0053] A2: The target height value of the component under test is obtained by using the preset height value to obtain the model through the distance between each preset movement distance and the distance between the corresponding adjacent reflected light patterns.
[0054] S12, the preset patterns of each reflected light are acquired through the photoelectric signal acquisition array. Due to the different heights, but the height of the light focusing is fixed, the digital patterns at different positions are different. Through digital image correlation (DIC) processing, the distances of movement of different patterns are obtained {{Y00,Y10,Y20...Yn0}...{Y0m,Y1m,Y2m...Ynm}}.
[0055] The digital image association method can be a global DIC algorithm or a local DIC algorithm;
[0056] S13, by fitting a preset function to the height value and the distance the pattern moves, obtain the functional relationship h(Yi,Li) of the preset height value, where Yi is the distance the pattern moves and Li is the height value;
[0057] The fitting methods include using least squares, gradient descent, and / or using neural networks. The neural network used can be a BP neural network with inputs Yi and Li and output hi, and m fully connected hidden layers in between.
[0058] S14, the height measuring component moves a distance {L0, L1, L2...Lx} (m>=0, x is a positive integer) in the X or Y direction, controlled by a preset external positioning platform, and reads the corresponding height value {Y0, Y1, Y2...Ym};
[0059] S15, determine whether the read height value is within the height range. If not, it may be due to a fault in the external positioning platform, a fault in the system, or the device height being outside the range of [h0-hn]. In this case, output the incorrect height.
[0060] S16, the height value read is averaged using the functional relationship of the height value, and the average value is the extrusion height hp.
[0061] The printing extrusion volume Fi of the print head is controlled by the control board of the 3D printer. The extrusion height hp corresponding to the preset extrusion volume is measured using one or more of the following: height measuring component or lidar, laser range sensor, and ultrasonic sensor. Based on the measurement, a neural network algorithm is used to fit the extrusion height hp and the printing extrusion volume Fi. The control board of the printer adjusts the motor speed or pump pressure of the part responsible for extrusion in the nozzle to adjust the extrusion volume.
[0062] S2, the three-dimensional model is converted into motion instructions through preset slicing software, including the extrusion amount Fi of the print head at each position. Preferably, the motion instructions are instructions used to control when the printer print head moves to which position.
[0063] S3. After each layer is printed, the height value hj of the actual printed content in that layer is measured using the height measurement component, and the print flow correction value Fpi is calculated to obtain the expected height to be achieved in the next layer. Then, the print flow correction value Fpi is used to continue printing in the next layer.
[0064] A three-axis motion mechanism drives the print head and height measurement component. The height measurement component passes through the area where the print has already been completed in the layer and records the actual height value hj of the printed content in that layer. The difference h between the actual height value hj and the ideal print height value hi is calculated using the print file. 差 The difference value h 差 By supplementing the flow using the theoretically based functional relationship hp(Fi,θ), the expected print flow correction value Fpi for the next layer should be calculated.
[0065] If the difference between the actual printed height hj and the ideal printed height hi is h 差 If the output is greater than or equal to a preset threshold ht, a failure result will be output and printing will stop. The preset threshold ht is a set safety limit determined by the range of the printer's extrusion flow. The printer's extrusion flow has a range; the greater the flow, the higher the height. However, if the height is too high, the printer cannot extrude that much flow, so a failure result will be output and printing will stop.
[0066] like Figure 3 As shown, the height measuring component includes a light source 101, a lens 102, a photoelectric signal acquisition array 103, and a processing unit 104. The light source 101 is located on one side of the photoelectric signal acquisition array 103. The light emitted by the light source 101 illuminates the measured plane 105. A portion of the light reflected by the measured plane 105 is received by the photoelectric signal acquisition array 103 to obtain an electrical signal. The electrical signal is processed by the processing unit to obtain height information.
[0067] The light source can be an LED light source or a laser light source. The lens is used to focus the light from the light source onto the vicinity of the plane to be measured. The photoelectric signal acquisition array is configured in accordance with the wavelength of the light source. The photoelectric signal acquisition array can be a CMOS or CCD device, or a photodiode array. The processing unit can receive the analog signal from the photoelectric signal acquisition array, convert it into a digital signal, and process it. The processing unit includes an ADC (analog-to-digital converter) and a computing unit such as an MCU, FPGA, or DSP.
[0068] In some preferred embodiments, the height measuring component and the print head are fixedly connected, the height measuring component moves with the print head, or both the print head and the height measuring component are always fixed; at least one height measuring component is disposed on one side of the print head.
[0069] Example 2
[0070] like Figure 4 As shown, this embodiment provides a 3D printing quality compensation system based on height information, the system comprising:
[0071] Height measuring component 1 is used to measure the printed height. The height measuring component includes a photoelectric signal acquisition array, a light source, a lens, and a processing unit. The light source is located on one side of the photoelectric signal acquisition array. The light emitted by the light source illuminates the plane being measured. A portion of the light reflected by the plane being measured is received by the photoelectric signal acquisition array to obtain an electrical signal. The electrical signal is processed by the processing unit to obtain height information.
[0072] The first function construction module 2 is used to establish the functional relationship hp(Fi,θ) of the theoretical basic height based on the printing extrusion amount Fi and the extrusion height hp, where θ is the set of other parameters that are identified to affect the printing height;
[0073] Conversion module 3 is used to convert the 3D model into motion instructions through preset slicing software, including the extrusion amount Fi of the printing nozzle at each position;
[0074] The acquisition module 4 is used to acquire a preset number of height values within a preset height range on the workpiece to be measured. By acquiring the preset number of height values within the preset height range on the workpiece to be measured, the motion mechanism of the height measuring component is driven to move a preset distance in the X or Y direction at each height value. During the movement, the photoelectric signal acquisition array records the preset patterns of each reflected light.
[0075] Data processing module 5 is used to obtain the distance the pattern has moved, which is obtained through a digital image association algorithm;
[0076] The second function construction module 6 is used to construct the functional relationship of height values, which is obtained by fitting a preset function to the height values and the distance the pattern moves.
[0077] This invention, through the second function construction module 6, constructs a functional relationship of height values during the pre-calibration stage, solving the problem that the contact switch installed on the machining actuator or fixed frame is prone to positional interference with the machining head and workpiece of the machining actuator. Based on the characteristic that the results obtained by the photoelectric signal acquisition array after the DIC algorithm are different when the positioning component moves the same distance at different heights, the functional relationship is constructed in the pre-calibration stage, and repeatable height measurement is performed using this functional relationship, solving the problems of high cost and low accuracy of the prior art.
[0078] The reading module 7 is used to preset the movement distance of the external positioning platform control height measuring component in the X or Y direction and read the corresponding height value;
[0079] Compensation module 8 is used to calculate the print flow correction value Fpi for the expected height of the next layer. After each layer is printed, a three-axis motion mechanism drives the nozzle and height measuring component. The height measuring component passes through the area where the layer has already been printed, records the actual height value hj of the printed content in that layer, and calculates the difference h between the actual height value hj and the ideal height hi using the print file. 差 The difference value h 差 The expected print flow correction value Fpi for the next layer is calculated based on the theoretical functional relationship hp(Fi,θ). This correction value is then used for printing at the next layer. If hj-hi=>ht, a failure result is output and printing stops, where ht is a preset threshold.
[0080] Analysis and judgment module 9 is used to determine whether the read corresponding height value is within the height range. If not, it outputs an error height.
[0081] Output module 10 is used to obtain the average value as the output result by reading the corresponding height value and using the functional relationship of the height value.
[0082] Although preferred embodiments of this application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this application.
Claims
1. A method for compensating the quality of 3D printing based on height information, characterized in that, The compensation method includes: (1) In the pre-calibration stage, the extrusion height hp is fitted with the corresponding printing extrusion amount Fi to obtain the functional relationship of the theoretical basic height hp(Fi,θ), where θ is the set of other parameters that are identified to affect the printing height; The method for obtaining the theoretically fundamental functional relationship hp(Fi,θ) during the calibration process is as follows: (11) Collect the preset height value within the preset height range on the workpiece to be measured, and move the preset distance in the X or Y direction by the motion mechanism of the height measuring component at each height value; (12) Obtain the pattern of each preset reflected light through the photoelectric signal acquisition array, and process it through the digital image association algorithm to obtain the distance the pattern moves; (13) By fitting a preset function to the height value and the distance the pattern moves, the functional relationship of the preset height value is obtained; (14) The height measuring component moves in the X or Y direction by a preset external positioning platform, and the corresponding height value is read. (15) Determine whether the read height value is within the preset height range. If not, output the error height. (16) The average value of the height reading is obtained by using the functional relationship of the height value. The average value is the extrusion height hp; (2) The three-dimensional model is converted into motion instructions by using preset slicing software, including the extrusion amount Fi of the printing nozzle at each position; (3) After each layer is printed, the height value hj of the actual printed content in that layer is measured using the height measurement component and the print flow correction value Fpi of the expected height to be achieved in the next layer is calculated and the print flow correction value Fpi is used to continue printing in the next layer. The specific steps of step (3) are as follows: A three-axis motion mechanism drives the print head and height measurement component. The height measurement component passes through the area where the print has already been completed in the layer and records the actual height value hj of the printed content in that layer. The difference h between the actual height value hj of the printed content in that layer and the ideal print height value hi is calculated using the print file. 差 The difference value h 差 The print flow correction value Fpi for the expected height that the next layer should achieve is calculated using the functional relationship hp(Fi,θ) based on the theoretical foundation.
2. The method for compensating the quality of 3D printing based on height information according to claim 1, characterized in that, In step (3), if the difference between the actual printed height hj and the ideal printed height hi is h... 差 If the value is greater than or equal to the preset threshold ht, output a failure result and stop printing.
3. The method for 3D printing quality compensation based on height information according to claim 1, characterized in that, The height measurement component includes a photoelectric signal acquisition array, a light source, a lens, and a processing unit. The light source is located on one side of the photoelectric signal acquisition array. The light emitted by the light source illuminates the plane being measured. A portion of the light reflected by the plane being measured is received by the photoelectric signal acquisition array to obtain an electrical signal. The electrical signal is processed by the processing unit to obtain height information.
4. The 3D printing quality compensation method based on height information according to claim 3, characterized in that, The height measuring component and the print head are fixedly connected. The height measuring component moves with the print head, or both the print head and the height measuring component remain fixed. At least one height measuring component is disposed on one side of the print head.
5. A 3D printing quality compensation system based on height information, characterized in that, The compensation system is applicable to any of the compensation methods described in claims 1-4, and the system comprises: Height measuring component, used to measure the printed height; The first function construction module is used to establish the functional relationship hp(Fi,θ) of the theoretical basic height based on the printing extrusion amount Fi and the extrusion height hp, where θ is the set of other parameters that are identified to affect the printing height; The conversion module is used to convert the 3D model into motion instructions through preset slicing software, including the extrusion amount Fi of the print head at each position. The acquisition module is used to acquire a preset number of height values within a preset height range on the workpiece to be measured. By acquiring the preset number of height values within the preset height range on the workpiece to be measured, the motion mechanism of the height measuring component is driven to move a preset distance in the X or Y direction at each height value. During the movement, the photoelectric signal acquisition array records the preset patterns of each reflected light. The data processing module is used to obtain the distance the pattern has moved, which is obtained through digital image association algorithms; The second function construction module is used to construct the functional relationship of height values, which is obtained by fitting a preset function to the height values and the distance the pattern moves. The reading module is used to preset the movement distance of the external positioning platform control height measuring component in the X or Y direction and read the corresponding height value; The compensation module is used to calculate the print flow correction value Fpi for the expected height that the next layer should achieve; The analysis and judgment module is used to determine whether the read height value is within the height range. If not, it outputs an error height. The output module is used to obtain the average value of the read height values using a functional relationship between the height values and the output result.
6. A 3D printing quality compensation system based on height information according to claim 5, characterized in that, The compensation module, after each layer is printed, drives the printhead and height measuring component via a three-axis motion mechanism. The height measuring component passes through the area where the layer has been printed and records the actual height value hj of the printed content within that layer. The module then calculates the difference h between the actual height value hj and the ideal height hi using the printed file. 差 The difference value h 差 The expected print flow correction value Fpi is calculated based on the theoretically based functional relationship hp(Fi,θ), and the next layer is printed with this correction value. If hj-hi=>ht, a failure result is output and printing is stopped, where ht is a preset threshold.
7. A 3D printing quality compensation system based on height information according to claim 5, characterized in that, The height measurement component includes a photoelectric signal acquisition array, a light source, a lens, and a processing unit. The light source is located on one side of the photoelectric signal acquisition array. The light emitted by the light source illuminates the plane being measured. A portion of the light reflected by the plane being measured is received by the photoelectric signal acquisition array to obtain an electrical signal. The electrical signal is processed by the processing unit to obtain height information.