Cutting path compensation method, system and cutting system for an aligner

Abstract

This invention relates to the field of orthodontic appliance manufacturing technology, and discloses a cutting path compensation method, system, and cutting system for orthodontic appliances. The cutting path compensation method includes: acquiring a module to be cut, the module including a carrier, a dental model fixed on the carrier, and a shell-shaped orthodontic appliance to be cut formed by hot pressing a diaphragm onto the dental model, the dental model including a positioning block protruding inwards from the dental arch, the dental model being fixed to the carrier by the positioning block; detecting the spatial pose of a detection surface and a reference surface based on a distance detection device; wherein the detection surface is the upper surface of the positioning block, and the reference surface is the bearing surface of the carrier; calculating the difference between the spatial pose of the bearing surface and the spatial pose of the detection surface, and compensating the initial digital cutting path corresponding to the dental model based on the difference to obtain a new digital cutting path.

Description

Technical Field

[0001] This invention relates to the field of orthodontic appliance manufacturing technology, and in particular to a cutting path compensation method, system and cutting system for orthodontic appliances. Background Technology

[0002] Shell-shaped orthodontic appliances are a type of orthodontic device made of safe, elastic, transparent polymer material. They have the advantages of being completely invisible during the orthodontic process, aesthetically pleasing, easy to operate, and convenient for oral cleaning. Moreover, due to their transparent and aesthetically pleasing characteristics, the orthodontic process is completed almost imperceptibly to others, and they have gradually become the first choice for orthodontic patients.

[0003] The production process of shell-shaped orthodontic appliances includes processes such as mold preparation, molding, marking, cutting, and cleaning. In the cutting process of shell-shaped orthodontic appliances, the dental model that has undergone the molding process is placed on the dental model carrier. Then, the dental model carrier and the dental model are transported to the cutting station for cutting to form a semi-finished module with cutting lines. After that, processes such as mold removal and polishing are carried out to obtain the finished orthodontic appliance. The entire manufacturing process is automated and efficient.

[0004] Existing semi-finished products have been found to have issues with low cutting precision, with some even cutting into the accessory cavities near the gingival line, rendering the orthodontic appliances unusable. Our researchers have discovered that since dental models are mostly printed using additive manufacturing, the bottom of the printed solid model may be uneven when it is unloaded from the additive manufacturing equipment, exhibiting irregularities such as bumps or tilted surfaces. The system's cutting path is designed based on the digital model, essentially a standard-positioned jaw model. Therefore, using the cutting path determined by the standard position to cut an uneven solid model results in low cutting precision and a low yield rate for orthodontic appliances. Furthermore, because orthodontic appliances require high precision, these unevenness or tilting errors, even if not visually perceptible, still affect the cut appliance. If these errors were eliminated through machine inspection, it would not only require additional high-precision inspection equipment, increasing costs, but also necessitate reprinting the discarded jaw models, which is time-consuming and increases printing costs due to the larger number of discarded models.

[0005] One existing solution is to digitally compensate for the cutting path. One specific compensation method is fixed-value compensation. This method places extremely high demands on the mounting and fixation of the dental model on the carrier, and is accompanied by numerous problems of poor appliance cutting due to the misalignment of actual and theoretical cutting paths. Another approach, such as the application by Zhejiang Zhengya (202211205893.4), involves detecting preset markers on the physical model, establishing a first coordinate system based on the detection results, comparing this first coordinate system with the second coordinate system of the detection equipment, and compensating based on the deviation of the coordinate systems. However, this method is limited by the precision of current additive manufacturing equipment, and because the markers are close to the bottom surface, the markers themselves may be affected by printing precision, resulting in positional deviations. Therefore, subsequent compensation using markers with positional deviations still has limited accuracy. Summary of the Invention

[0006] The purpose of this invention is to provide a method, system, and cutting system for compensating the cutting path of orthodontic appliances. The compensation amount is accurately determined, which can improve the precision of the orthodontic appliance cutting process, increase the yield of orthodontic appliance products, and at the same time basically maintain the manufacturing cycle and manufacturing cost.

[0007] To address the aforementioned technical problems, embodiments of the present invention provide a cutting path compensation system for an orthodontic appliance, comprising: acquiring a module to be cut, the module including a carrier, a dental model fixed on the carrier, and a shell-shaped orthodontic appliance to be cut formed by hot-pressing a diaphragm onto the dental model, the dental model including a positioning block protruding inwards from the dental arch, the dental model being fixed to the carrier by the positioning block; detecting the spatial pose of a detection surface and a reference surface based on a distance detection device; wherein the detection surface is the upper surface of the positioning block, and the reference surface is the bearing surface of the carrier; calculating the difference between the spatial pose of the bearing surface and the spatial pose of the detection surface, and compensating the initial digital cutting path corresponding to the dental model based on the difference to obtain a new digital cutting path.

[0008] An embodiment of the present invention also provides a cutting path compensation system for an orthodontic appliance, used to implement the above-described cutting path compensation method for an orthodontic appliance, comprising: a loading module, a positioning module, a processing module, and a controller; the positioning module and the processing module are respectively connected to the controller; wherein, the loading module is used to receive the module to be cut, the dental model including a positioning block protruding inwards from the dental arch, the dental model being fixed to a carrier by the positioning block; the controller controls the positioning module to detect the spatial pose of a detection surface and a reference surface based on a distance detection device; wherein, the detection surface is the upper surface of the positioning block, and the reference surface is the bearing surface of the carrier; the controller controls the processing module to obtain the initial digital cutting path corresponding to the dental model, and to determine the difference between the spatial pose of the bearing surface and the spatial pose of the detection surface, and to compensate the digital cutting path corresponding to the dental model based on the difference.

[0009] Compared to existing technologies, this invention employs distance detection to separately detect the detection surface on the positioning block of the dental model and the reference surface on the carrier, thereby determining the spatial pose of the dental model and the carrier surface. Since dental models have varying surface textures and shapes, this application specifically uses protruding positioning blocks on the dental model as the detection points, ensuring the dental model's shape is not affected while maintaining a flat detection area. Subsequently, a digital cutting path is obtained through pose difference compensation to obtain a cutting path more suitable for the actual dental model in the current pose, improving the yield of the orthodontic appliance after cutting. Simultaneously, because the digital cutting path is compensated by software, the accuracy requirements for the placement of the dental model are reduced, increasing the online availability rate of the dental model and significantly reducing the time and material costs incurred due to physical model re-creation. Therefore, the technical solution of this application requires minimal hardware modifications, adapts to existing production processes, controls costs, accurately determines the compensation amount, and greatly improves the yield of the finished orthodontic appliance.

[0010] Optionally, the detection of the spatial pose of the detection surface and the spatial pose of the reference surface based on the distance detection device includes: detecting the spatial pose of the detection surface based on a first distance detection device; and detecting the spatial pose of the reference surface based on a second distance detection device.

[0011] Optionally, the first distance detection device and the second distance detection device are arranged such that the detection direction is perpendicular to the bearing surface.

[0012] Optionally, there are at least three first distance detection devices, and the three points projected onto the plane of the bearing surface are not collinear. By measuring the spatial positions of the three points on the detection surface and determining whether the bottom of the dental model is placed parallel to the carrier based on the spatial positions of these three points, the unevenness of the solid model in multiple dimensions can be determined. This method is simple to implement and has low hardware costs.

[0013] Optionally, the three first distance detection devices are arranged such that three points projected onto the xy plane of the reference coordinate system built into the cutting path compensation system form the three vertices of a right triangle. Arranging the three first distance detection devices in a right triangle allows for direct calculation of the tilt amount used for compensation using the spatial coordinates of the three points, eliminating the need for coordinate transformation and simplifying the process.

[0014] Optionally, the first distance detection device projected onto the right-angle vertex is a first sensor, and the other two are a second sensor and a third sensor, respectively. The processing module is further configured to calculate a first tilt of the dental model relative to the bearing surface based on the height values ​​measured by the first and second sensors; calculate a second tilt of the dental model relative to the bearing surface based on the height values ​​measured by the first and third sensors; and compensate for the spatial position of the initial digital cutting path based on the first and second tilts. In this application, three sensors are arranged in a right-angled triangle, and the tilt on each of the two right-angled sides is calculated, which can achieve compensation for the spatial position of the cutting line, and the calculation is simple.

[0015] Optionally, the first and second tilt values ​​are represented using Cartesian, Lagrange, or Eulerian coordinate systems. Different coordinate systems can be used to represent the position, allowing for adaptation to various systems and expanding application scenarios.

[0016] Optionally, the first distance detection device is a single unit, and the compensation system further includes a motion module fixedly connected to the first distance detection device, used to drive the first distance detection device to reciprocate at at least three detection positions. By combining the motion module and the distance detection device, multiple positions can be detected with only one distance detection device, making the detection positions more flexible and increasing the accuracy of pose determination when detecting more positions.

[0017] Optionally, it further includes: compensating for the height value of the initial digital cutting path; including: obtaining the difference Δh between the height values ​​measured by the first distance detection device and the second distance detection device; and obtaining the design thickness H of the positioning block in the dental model; and compensating for the height value of the digital cutting path based on the difference between Δh and H. This application obtains the height difference, i.e., the actual thickness of the positioning block, through distance detection, and then combines it with the design thickness of the positioning block to determine the possible height error in the placement position, and further compensates for the height error, making the cutting path more accurate.

[0018] Optionally, the first distance detection device and / or the second distance detection device may be a contact sensor or a laser sensor.

[0019] Optionally, the dental model is provided with an identification code, and the compensation method further includes: identifying the identification code of the dental model, and retrieving the initial digital cutting path of the dental model from the information database according to the identification code.

[0020] Embodiments of the present invention also provide a cutting system for an orthodontic appliance, comprising: a cutting device, a motion module, and a cutting path compensation system for the orthodontic appliance as described above; a controller in the cutting path compensation system is communicatively connected to the motion module; the controller controls the motion module to drive the cutting device or the dental model to move according to the digital cutting path output by the cutting path compensation system, so as to realize that the cutting device cuts on the dental model to obtain the orthodontic appliance.

[0021] Compared with the prior art, this embodiment obtains a more accurate cutting path based on the cutting path compensation system, and then cuts the dental model according to the compensated target cutting path, so that the cutting path is more compatible with the current dental model, resulting in a higher yield of orthodontic appliances formed after cutting.

[0022] Optionally, the motion module is a robotic arm, with a pickup component at its end. The controller controls the movement of the robotic arm, allowing the pickup component to pick up the dental model. The controller also controls the robotic arm to move the dental model along the digital cutting path at the cutting position of the cutting device, completing the orthodontic appliance cutting. This application further specifies the motion module as a robotic arm, which drives the dental model to complete the cutting. This method is compatible with existing laser cutting and mechanical cutting processes, requires almost no changes to existing manufacturing procedures, adds minimal hardware, and has low cost. The improvement is effective, significantly increasing the yield rate of finished orthodontic appliances. Attached Figure Description

[0023] One or more embodiments are illustrated by way of example with reference numerals in the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Elements with the same reference numerals in the drawings are denoted as similar elements. Unless otherwise stated, the figures in the drawings are not to be limited by scale.

[0024] Figure 1 This is a flowchart of the cutting path compensation method for the orthodontic appliance provided in the first embodiment of this application;

[0025] Figure 2a This is a structural diagram of the system in the cutting path compensation method for the orthodontic appliance provided in the first embodiment of this application;

[0026] Figure 2b This is a three-dimensional schematic diagram of the system in the cutting path compensation method of the orthodontic appliance provided in the first embodiment of this application;

[0027] Figure 2c yes Figure 2b A diagram from a top-down perspective;

[0028] Figure 3 This is a schematic diagram of the positional relationship between the dental model and the carrier in the cutting path compensation method for the orthodontic appliance provided in the first embodiment of this application;

[0029] Figure 4 This is a flowchart of another method for compensating the cutting path of an orthodontic appliance provided in the first embodiment of this application;

[0030] Figure 5 This is a schematic diagram of the dental model of an example of the cutting path compensation method for orthodontic appliances provided in the first embodiment of this application;

[0031] Figure 6 This is a schematic diagram illustrating the positional relationship between the dental model and the carrier detection area in the cutting path compensation method for the orthodontic appliance provided in the first embodiment of this application.

[0032] Figure 7 This is a schematic diagram of the positional relationship between the dental model and the carrier in the cutting path compensation method for the orthodontic appliance provided in the second embodiment of this application;

[0033] Figure 8 This is a schematic diagram of the cutting system of the orthodontic device provided in the fourth embodiment of this application. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of this invention clearer, the various embodiments of this invention will be described in detail below with reference to the accompanying drawings. However, those skilled in the art will understand that many technical details have been provided in the various embodiments of this invention to facilitate a better understanding of this application. However, the technical solutions claimed in the claims of this application can be implemented even without these technical details and with various variations and modifications based on the following embodiments.

[0035] In embodiments of the present invention, the terms "upper," "lower," "left," "right," "front," "rear," "top," "bottom," "inner," "outer," "middle," "vertical," "horizontal," "lateral," and "longitudinal" indicate orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings. These terms are primarily for the purpose of better describing the present invention and its embodiments, and are not intended to limit the indicated devices, elements, or components to having a specific orientation, or to require them to be constructed and operated in a specific orientation. Furthermore, some of the aforementioned terms may be used to indicate other meanings besides orientation or positional relationships; for example, the term "upper" may in some cases indicate a dependency or connection relationship. Those skilled in the art can understand the specific meaning of these terms in the present invention according to the specific circumstances.

[0036] Furthermore, the terms "first," "second," etc., are primarily used to distinguish different devices, elements, or components (which may be the same or different in specific type and construction), and are not intended to indicate or imply the relative importance or quantity of the indicated devices, elements, or components. Unless otherwise stated, "a plurality of" means two or more.

[0037] The inventors of this application discovered in their research on orthodontic appliance manufacturing processes that, in order to adapt to solid dental models with insufficiently precise positioning, it is necessary to compensate for the digital cutting path based on the current positioning, and determining the amount of compensation is crucial. This application specifically employs multiple sensors to detect the spatial positioning of the dental model and the spatial positioning of the reference bearing surface. By compensating for the positional differences in the digital cutting path, a cutting path more suitable for the solid dental model in the current positioning is obtained, improving the yield of the orthodontic appliance after cutting. Simultaneously, because the digital cutting path is compensated by software, the accuracy requirements for the placement of the dental model are reduced, increasing the availability of dental models and significantly reducing the time and material costs incurred due to the remaking of physical models. Therefore, the technical solution of this application requires minimal hardware modifications, adapts to existing production processes, and accurately determines the compensation amount while controlling costs, greatly improving the yield of the finished orthodontic appliance.

[0038] The following details the implementation of the cutting path compensation method, system, and cutting system of the orthodontic appliance in this application. The following implementation details are provided for ease of understanding and are not necessary for implementing this solution.

[0039] The first embodiment of the present invention provides a method for compensating the cutting path of an orthodontic appliance.

[0040] First, it should be noted that the cutting path compensation method for the orthodontic appliance in this embodiment is applied to a system. For hardware implementation, the processing steps in the cutting path compensation method can be implemented using one or more application-specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DAPDs), programmable logic devices (PLDs), field-programmable gate arrays (FPGAs), processors, controllers, microcontrollers, microprocessors, other electronic devices for implementing the cutting path compensation function of the orthodontic appliance, or a combination of the above devices. An example is... Figure 2a The system shown includes a feeding module 10, a positioning module 20, and a processing module 30.

[0041] The process of the cutting path compensation method in this embodiment is as follows: Figure 1 As shown, it specifically includes:

[0042] Step 101: Obtain the module to be cut.

[0043] Specifically, the module to be cut includes a carrier, a dental model fixed on the carrier, and a shell-shaped orthodontic appliance to be cut, formed by hot-pressing a diaphragm onto the dental model. The dental model includes a positioning block protruding inwards from the dental arch, and the dental model is fixed to the carrier by the positioning block. More specifically, to Figure 3 For example, the dental model 40 includes a dental model body 41 and a positioning block 42 protruding inwards from the dental arch. The side of the positioning block away from the bottom of the dental model is a preset detection surface. The dental model body 41 is fixed to the carrier 50 by the positioning block 42. Specifically, the upper surface of the carrier 50 is a reference surface, and a positioning pin (not shown in the figure) may be provided on the reference surface. The dental model 40 can be connected to the positioning pin through the positioning block 42, specifically through the positioning hole 43 on the positioning block 42, thereby fixing it to the carrier 50. Since the relative position of the dental model 40 to the carrier 50 remains almost unchanged when the dental model 40 flows on the production line, detecting the positioning block can be equivalent to detecting the actual dental model.

[0044] In some embodiments, this step can be performed by the loading module 10, which can be configured as a conveyor belt connected to the cutting station. The solid dental arch model 40 is fixed on the carrier 50, having already completed the previous molding and marking processes. Specifically, the dental model 40 containing the user's dental arch and thermoforming material can be manually loaded onto the conveyor belt, or it can be automatically transferred from the molding and marking station by the system. In practical applications, the positional relationship of each module in the system can be as follows: Figure 2b As shown.

[0045] Step 102: Detect the spatial pose of the detection surface and the spatial pose of the reference surface based on the distance detection device.

[0046] Specifically, the detection surface is the upper surface of the positioning block, and the reference surface is the bearing surface of the carrier.

[0047] In some embodiments, the distance detection device can be as follows: Figure 2b As shown, it specifically includes: a first distance detection device 201 positioned facing the detection surface, used to detect the spatial pose of the detection surface; and a second distance detection device 202 positioned facing the side of the carrier 50 that supports the dental model 40, used to detect the spatial pose of the carrier 50's supporting surface. Specifically, as... Figure 3 As shown, a detection area 51 is provided on the vehicle 50, corresponding to the position of the second distance detection device 202.

[0048] In one embodiment, the first distance detection device 201 and the second distance detection device 202 described above can be contact sensors, such as contact digital displacement sensors, or laser sensors. In practical applications, the first distance detection device 201 and the second distance detection device 202 can be of different types, one being a contact sensor and the other a laser sensor; these will not be listed here. Figure 2b and Figure 2c For example, the first distance detection device 201 and the second distance detection device 202 can be driven by a drive device 203 (such as a cylinder) to perform the detection action.

[0049] In practical applications, the system has a built-in reference coordinate system. The z-axis direction is the detection direction of the first distance detection device 201, and the xy-plane is the direction of the bearing surface. The detection direction is approximately perpendicular to the xy-plane. Specifically, there can be at least three first distance detection devices 201, and the three points projected onto the xy-plane are not collinear. By measuring the spatial position of the three points on the detection surface and determining whether the bottom of the dental model 40 is placed parallel to the carrier 50 based on the spatial position of these three points, the unevenness of the solid model in multiple dimensions can be determined. This is simple to implement and has low hardware costs. It is understood that more first distance detection devices 201 can be deployed, and more detection devices can detect more accurate poses.

[0050] Furthermore, in this embodiment, the spatial pose of the detection surface and the spatial pose of the reference surface are characterized by the distance parameters detected by the distance detection device. Figure 2b and 2cFor example, the three first distance detection devices 201 are arranged such that three points projected onto the xy plane in the built-in reference coordinate system of the compensation system form the three vertices of a right triangle. Arranging the three first distance detection devices 201 in a right triangle allows for direct calculation of the tilt amount used for compensation using the spatial coordinates of the three points, eliminating the need for coordinate transformation and simplifying the process. Each of the three first distance detection devices 201 can detect three height values, which can then be used as the coordinates of the three points on the z-axis. The positions of the three first distance detection devices 201 projected onto the xy plane can be calibrated during equipment installation or measured in the mechanical assembly drawing. Once the spatial positions of the three non-collinear points on the detection surface are obtained, the spatial pose of the detection surface can be characterized. In this embodiment, the pose of the positioning surface is determined based on the accurate assembly of the carrier. The positioning surface is determined by the height detected by the second distance detection device 202, and the extension direction of the surface is based on the direction parallel to the xy plane.

[0051] Step 103: Calculate the difference between the spatial pose of the bearing surface and the spatial pose of the detection surface.

[0052] Specifically, the difference is calculated based on the spatial pose detected in step 102. Continuing with... Figure 2a and Figure 2b For example, the first distance detection device 201 projected onto the vertex of the right angle is a first sensor, and the other two are a second sensor and a third sensor, respectively. The processing module 30 is also used to calculate the first tilt of the dental model 40 relative to the bearing surface based on the height values ​​measured by the first and second sensors; to calculate the second tilt of the dental model 40 relative to the bearing surface based on the height values ​​measured by the first and third sensors; and to compensate for the spatial position of the initial digital cutting path based on the first and second tilts. In this application, three sensors are arranged in a right-angled triangle, and the tilt on each of the two right-angled sides is calculated, which can realize the compensation for the spatial position of the cutting line, and the calculation is simple.

[0053] To further clarify, the first and second tilt values ​​are represented using Cartesian, Lagrange, or Eulerian coordinate systems. The limitation is that different coordinate systems can be used to represent the position, allowing for adaptation to various systems and expanding application scenarios. This embodiment uses the Eulerian coordinate system as an example. The Eulerian coordinate system can be used to describe the orientation of a rigid body in three-dimensional space relative to a fixed coordinate system using three angles. These three angles uniquely determine the position and orientation of the rigid body; they are rotation angles about the three coordinate axes, typically denoted as α (rotation angle about the x-axis), β (rotation angle about the y-axis), and γ (rotation angle about the z-axis). Compared to the Cartesian coordinate system, the Eulerian coordinate system can more intuitively describe changes in the rigid body's orientation, and requires fewer parameters for subsequent control.

[0054] Step 104: Compensate the initial digital cutting path corresponding to the dental model based on the difference amount to obtain a new digital cutting path.

[0055] Further with Figure 6 Taking an example, the compensation process of this embodiment is explained. The calculation method of each tilt amount is illustrated using a Cartesian coordinate system. The dental model shown in the figure is the side facing the sensor, which can also be a top view. Point a in the figure is the point detected by the first sensor, and points b and c are the points detected by the second and third sensors, respectively. The specific calculation process includes:

[0056] Taking point a as the calculation reference point, and with the projections of ab and ac onto the XY plane perpendicular to each other, and the sensor detection direction being the Z direction, the positional relationship of surface abc relative to the bearing surface is calculated in the coordinate system built into the compensation system. First, x, y, z, Rx, Ry, and Rz are calculated respectively, where x, y, and z are the differences between surface abc and the bearing surface on the XYZ axes, and Rx, Ry, and Rz are the rotations of surface abc relative to the bearing surface around the XYZ axes. In one embodiment, the dental model 40 is fixed to the carrier 50 by positioning pins. Due to the limiting effect of the positioning pins, especially in scenarios where two positioning pins are used for limiting (e.g....), Figure 5 (As shown in the diagram), x, y, and Rz are fixed values ​​that will be obtained through testing during debugging. In some embodiments, the Z-axis can also be ignored. Specifically, during the initial loading process, the dental model is pressed firmly onto the carrier, ensuring that the dental model and the carrier's bearing surface are basically in contact. The first distance detection device (i.e., three sensors) is driven to measure the height values ​​h of points a, b, and c, respectively. a h b h c .

[0057] The formula for calculating Ry using the heights detected by a and b is:

[0058] Rx is calculated using the heights detected by a and c, using the following formula:

[0059] Among them, in the formula This represents the projected distance between points a and b on the XY plane. This represents the projected distance between points a and c on the XY plane. These two distances can be calibrated during equipment installation or measured in mechanical assembly drawings.

[0060] It should also be noted that the initial digital cutting path in this step can be pre-stored in the processing module 30 and retrieved when needed, or it can be received when the dental model 40 currently being loaded arrives, based on the product flow. The orthodontic appliance cutting path compensation method in this embodiment further includes: identifying the identity code of the dental model, and retrieving the initial digital cutting path of the dental model from the database based on the identity code. Figure 4 An example flowchart is provided, in which steps 401, 403-405 are the same as those described above. Figure 1 Similar to steps 101-104 in the previous example, in practical applications, the order of step 402 is not limited to before step 403; it can also be performed after step 403 or simultaneously with step 403. This will not be elaborated further here. The corresponding dental model 40 is as follows: Figure 5 As shown, the identification code can be located on the positioning block, visible to the side facing the crown, such as in a raised or recessed form or in a hollowed-out form. In other embodiments, it can also be located on the side wall of the tooth base. As can be seen, the position set in the above embodiments is easy to read and will not affect the shape of the crown.

[0061] It is worth mentioning that after calculating the aforementioned differences, these differences are superimposed on the initial digital cutting path to obtain the updated digital cutting path. In practical applications, the measured and calculated x, y, Rx, Ry, and Rz values ​​can also be transmitted from the PLC to the cutting system to complete the compensation of the digital cutting path. In one embodiment, the cutting system can perform the calculation of the compensation amount.

[0062] It is understood that, in addition to the above-mentioned methods for calculating the difference, other methods can also be used. For example, on the one hand, based on the spatial positions of points a, b, and c, the first equation expression of the surface passing through point abc can be determined; on the other hand, the second equation expression of the reference surface can be determined, and the transformation matrix between the two equation expressions can be calculated. This transformation matrix can represent the difference. During digital cutting path compensation, the initial digital cutting path is used to calculate the compensated digital cutting path based on the transformation matrix. Therefore, there are multiple methods for calculating the difference, which will not be listed here.

[0063] It is also understood that, in addition to the hardware scenarios mentioned above, other hardware scenarios can be used in practical applications. For example, to detect points a, b, and c, besides the aforementioned layout of the distance detection device, other methods can be used. For instance, a first distance detection device can be deployed, and during detection, this device can be controlled to move along the xy-plane, detecting the height at points a, b, and c respectively, thus obtaining the height values ​​of points a, b, and c. Correspondingly, the positions of the projections of points a, b, and c in the xy-plane can be determined by a preset trajectory or by the amount of movement of the detection device, which will not be elaborated further here. Furthermore, compensation amounts in other corresponding directions can be measured or calculated according to actual needs, which will not be listed here one by one.

[0064] As can be seen, compared with the prior art, this embodiment uses distance detection to detect the detection surface on the positioning block of the dental model and the reference surface on the carrier, thereby determining the spatial pose of the dental model and the carrier surface respectively. Since the surface of the dental model is uneven and varies in shape, this application specifically uses the protruding positioning block on the dental model as the detection position, ensuring that the shape of the dental model itself is not affected, provided the detection area is flat. Then, by compensating for pose differences, a digital cutting path is obtained to obtain a cutting path more suitable for the actual dental model in the current pose, improving the yield of the orthodontic appliance after cutting. At the same time, because the digital cutting path is compensated by software, the accuracy requirements for the placement of the dental model are reduced, increasing the online availability rate of the dental model and greatly reducing the time and material costs incurred due to the remaking of the physical model. Therefore, the technical solution of this application requires minimal hardware modification, is compatible with existing production processes, and while controlling costs, accurately determines the compensation amount, greatly improving the yield of the finished orthodontic appliance.

[0065] The second embodiment of this application provides a cutting path compensation method for orthodontic appliances. Compared with the first embodiment, the main improvement of this embodiment is that it adds compensation for the height of the digital cutting path, so that the compensated digital cutting path is more in line with the current dental model placement, and the edge of the orthodontic appliance cut is more accurate.

[0066] The orthodontic appliance cutting path compensation method in this embodiment further includes: compensating for the height value of the initial digital cutting path. Specifically, it further includes: obtaining the difference Δh between the height values ​​measured by the first distance detection device and the second distance detection device (e.g., ...). Figure 7(as shown); and, obtaining the design thickness H of the positioning block in the dental model; compensating the height value of the digital cutting path based on the difference between Δh and H. Specifically, the design thickness H of the positioning block can be obtained from design parameters or measured from the digital model corresponding to the dental model. This application obtains the height difference, i.e., the actual thickness of the positioning block, through distance detection, and then, combined with the design thickness of the positioning block, determines the possible height error in the placement position, and further compensates for the height error, making the cutting path more accurate.

[0067] In one embodiment, when compensating for the initial digital cutting path corresponding to the dental model based on the difference, the height of each point on the cutting path can be compensated for the height error. In practical applications, methods such as coordinate system transformation can also be used for cutting path compensation, which will not be listed here.

[0068] In this embodiment, by compensating for the height of the digital cutting path, the problem of height error in the placement of the dental model is made up, thus achieving more accurate cutting of the orthodontic appliance.

[0069] It is worth mentioning that the examples above in this application are merely illustrative for ease of understanding and do not constitute a limitation on the technical solutions of this invention.

[0070] The steps of the various methods described above are only for clarity. In practice, they can be combined into one step or some steps can be split into multiple steps. As long as they include the same logical relationship, they are all within the scope of protection of this patent. Adding insignificant modifications or introducing insignificant designs to the algorithm or process, but without changing the core design of the algorithm and process, are also within the scope of protection of this patent.

[0071] The third embodiment of this application provides a cutting path compensation system for orthodontic appliances, used to implement the above-described cutting path compensation method for orthodontic appliances, such as... Figure 2a Specifically, it includes: a feeding module 10, a positioning module 20, a processing module 30, and a controller 60; the positioning module 20 and the processing module 30 are respectively connected to the controller 60; wherein,

[0072] The loading module 10 is used to receive the dental model to be cut. The dental model includes a positioning block protruding inwards from the dental arch, and the dental model is fixed to the carrier by the positioning block. In some embodiments, the loading module 10 can be a workbench. In one embodiment, the loading can be done manually, placing the dental model to be cut into a predetermined position on the workbench, or it can be placed into a predetermined position on the workbench by an automatic transfer mechanism. In other embodiments, the loading module 10 can be a conveyor belt, which can be controlled by the controller 60 to transport the dental model to be cut from the loading position to the current workstation. Further examples are not listed here.

[0073] The controller 60 controls the positioning module 20 to detect the spatial pose of the detection surface and the spatial pose of the reference surface based on the distance detection device; wherein, the detection surface is the upper surface of the positioning block, and the reference surface is the bearing surface of the vehicle.

[0074] The controller 60 controls the processing module 30 to acquire the initial digital cutting path corresponding to the dental model, and determines the difference between the spatial pose of the bearing surface and the spatial pose of the detection surface, and compensates the digital cutting path corresponding to the dental model based on the difference.

[0075] In some embodiments, the controller 60 may be a PLC controller. It is understood that in practical applications, it may also be other control systems, which will not be listed here.

[0076] As can be seen, the cutting path compensation system for the orthodontic appliance in this embodiment uses distance detection to detect the detection surface on the positioning block of the dental model and the reference surface on the carrier, thereby determining the spatial pose of the dental model and the carrier surface respectively. Since the surface of the dental model is uneven and varies in shape, this application specifically uses the protruding positioning block on the dental model as the detection position, ensuring that the shape of the dental model itself is not affected under the premise that the detection area is flat. Then, by compensating for pose differences, a digital cutting path is obtained to obtain a cutting path more suitable for the actual dental model in the current pose, improving the yield of the orthodontic appliance after cutting. At the same time, because the digital cutting path is compensated by software, the accuracy requirements for the placement of the dental model are reduced, increasing the online availability rate of the dental model and greatly reducing the time and material costs incurred due to the remaking of the physical model. Therefore, the technical solution of this application requires minimal hardware modification, is compatible with existing production processes, and while controlling costs, accurately determines the compensation amount, greatly improving the yield of the finished orthodontic appliance.

[0077] The fourth embodiment of this application provides a cutting system for an orthodontic appliance, such as Figure 8As shown, it includes: a cutting device 80, a motion module 70, and a cutting path compensation system for the orthodontic appliance as described above; wherein, the controller 60 in the cutting path compensation system is communicatively connected to the motion module; the controller 60 controls the motion module 70 to drive the dental model to move according to the digital cutting path output by the cutting path compensation system, so as to realize the cutting device cutting on the dental model to obtain the orthodontic appliance.

[0078] by Figure 8 Taking this example, the motion module 70 is a robotic arm, with a pickup component 71 at its end. The controller 60 controls the movement of the robotic arm, allowing the pickup component 71 to pick up the dental model. The controller also controls the robotic arm to move the dental model along a digital cutting path at the cutting position of the cutting device 80, completing the orthodontic appliance cutting. This embodiment further defines the motion module as a robotic arm, which drives the dental model to complete the cutting. It is compatible with existing laser cutting and mechanical cutting processes, requires almost no changes to existing manufacturing procedures, adds little hardware, and has low cost. Its improvement is effective, and the yield rate of finished orthodontic appliances is greatly improved.

[0079] In other embodiments, the motion module 70 can be connected to the cutting equipment. Correspondingly, the dental model is fixed on the worktable, and the controller sends the compensated digital cutting path to the robotic arm. After receiving the digital cutting path, the robotic arm drives the cutting equipment to move and completes the cutting of the orthodontic appliance.

[0080] As can be seen, the cutting system in this embodiment, based on the more accurate cutting path obtained by the above-mentioned cutting path compensation system, cuts the dental model according to the compensated target cutting path, making the cutting path more compatible with the current dental model, and thus making the yield of the orthodontic appliance formed by the cutting device higher.

[0081] Those skilled in the art will understand that the above embodiments are specific embodiments for implementing this application, and in practical applications, various changes can be made to them in form and detail without departing from the spirit and scope of this application.

Claims

1. A method for compensating the cutting path of an orthodontic appliance, characterized in that, Applied to the system, including: Obtain a module to be cut, the module to be cut includes a carrier, a dental model fixed on the carrier, and a shell-shaped orthodontic appliance to be cut formed by hot pressing a diaphragm onto the dental model. The dental model includes a positioning block protruding into the dental arch, and the dental model is fixed to the carrier by the positioning block. The spatial pose of the detection surface and the spatial pose of the reference surface are detected by the distance detection device respectively; wherein, the detection surface is the upper surface of the positioning block, and the reference surface is the bearing surface of the vehicle; The difference between the spatial pose of the bearing surface and the spatial pose of the detection surface is calculated, and the initial digital cutting path corresponding to the dental model is compensated based on the difference to obtain a new digital cutting path.

2. The cutting path compensation method for the orthodontic appliance according to claim 1, characterized in that, The method of detecting the spatial pose of the detection surface and the spatial pose of the reference surface based on the distance detection device includes: The spatial pose of the detection surface is detected based on a first distance detection device; and the spatial pose of the reference surface is detected based on a second distance detection device.

3. The method for compensating the cutting path of the orthodontic appliance according to claim 2, characterized in that, The first distance detection device and the second distance detection device are arranged such that the detection direction is perpendicular to the bearing surface.

4. The cutting path compensation method for the orthodontic appliance according to claim 3, characterized in that, There are at least three first distance detection devices, and the three points projected onto the plane of the bearing surface are not collinear.

5. The cutting path compensation method for the orthodontic appliance according to claim 4, characterized in that, The three first distance detection devices are arranged such that three points projected onto the xy plane of the reference coordinate system built into the cutting path compensation system form the three vertices of a right triangle.

6. The method for compensating the cutting path of the orthodontic appliance according to claim 5, characterized in that, The first distance detection device projected onto the vertex of the right angle is the first sensor, and the other two are the second sensor and the third sensor, respectively. The step of detecting the spatial pose of the detection surface based on the first distance detection device includes: calculating a first tilt of the dental model relative to the bearing surface based on the height values ​​measured by the first sensor and the second sensor; calculating a second tilt of the dental model relative to the bearing surface based on the height values ​​measured by the first sensor and the third sensor; and compensating for the spatial position of the initial digital cutting path based on the first tilt and the second tilt.

7. The cutting path compensation method for the orthodontic appliance according to claim 6, characterized in that, The first tilt and the second tilt are represented by coordinates in Cartesian, Lagrange, or Euler coordinate systems.

8. The method for compensating the cutting path of the orthodontic appliance according to claim 3, characterized in that, The first distance detection device is one unit, and the compensation system further includes: a motion module fixedly connected to the first distance detection device, used to drive the first distance detection device to move back and forth at at least three detection positions.

9. The method for compensating the cutting path of an orthodontic appliance according to claim 2, characterized in that, Also includes: Compensate for the height value of the initial digital cutting path; These include: Obtain the height difference Δh measured by the first distance detection device and the second distance detection device; and obtain the design thickness H of the positioning block in the dental model; The height value of the digital cutting path is compensated based on the difference between Δh and H.

10. The method for compensating the cutting path of the orthodontic appliance according to any one of claims 1-9, characterized in that, The dental model is equipped with an identification code, and the compensation method further includes: identifying the identification code of the dental model, and retrieving the initial digital cutting path of the dental model from the information database according to the identification code.

11. The method for compensating the cutting path of the orthodontic appliance according to any one of claims 2-9, characterized in that, The first distance detection device and / or the second distance detection device are contact sensors or laser sensors.

12. A cutting path compensation system for an orthodontic appliance, characterized in that, A method for compensating the cutting path of the orthodontic appliance according to any one of claims 1-11, comprising: a feeding module, a positioning module, a processing module, and a controller; wherein the positioning module and the processing module are respectively connected to the controller; wherein... A feeding module is used to receive the dental model to be cut. The dental model includes a positioning block protruding into the dental arch, and the dental model is fixed to the carrier by the positioning block. The controller controls the positioning module to detect the spatial pose of the detection surface and the spatial pose of the reference surface based on distance detection; wherein, the detection surface is the upper surface of the positioning block, and the reference surface is the bearing surface of the vehicle; The controller controls the processing module to obtain the initial digital cutting path corresponding to the dental model, and determines the difference between the spatial pose of the bearing surface and the spatial pose of the detection surface, and compensates the digital cutting path corresponding to the dental model based on the difference.

13. A cutting system for an orthodontic appliance, characterized in that, include: Cutting equipment, motion module, and cutting path compensation system for the orthodontic appliance as described in claim 12; The controller in the cutting path compensation system is communicatively connected to the motion module; The controller controls the motion module to drive the cutting device or the dental model to move according to the digital cutting path output by the cutting path compensation system, so as to realize the cutting device cutting on the dental model to obtain the orthodontic appliance.

14. The cutting system for the orthodontic appliance according to claim 13, characterized in that, The motion module is a robotic arm, and the end of the robotic arm is equipped with a pickup component. The controller controls the movement of the robotic arm, the pickup component picks up the dental model, and the controller controls the robotic arm to drive the dental model to move along the digital cutting path at the cutting position of the cutting device to complete the orthodontic appliance cutting.

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