Surface type determination method, device and equipment and computer storage medium

Abstract

The invention provides a surface type determination method, apparatus and device, and a computer storage medium. The method comprises the steps of obtaining an actual clamping pressure applied to an element fixing mechanism by a to-be-measured optical element, and an initial surface type point cloud under the actual clamping pressure; based on the actual clamping pressure and a preset deformation relation, the position offset of at least one point cloud point in the initial surface type point cloud is determined, and the deformation relation represents the deformation of at least one point on the to-be-measured optical element under different clamping pressures; the positional offset is applied to at least one point cloud point in the initial face profile point cloud to generate a compensated face profile.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the field of optical measurement, and in particular, to a surface shape determination method, device, equipment and computer storage medium. BACKGROUND

[0002] In the modern automotive industry, head-up display (HUD) systems are becoming increasingly popular. The HUD system usually uses the front windshield of the vehicle as the reflection body of the projected image, and projects the vehicle speed, navigation and other information into the driver's line of sight. In this application scenario, the accuracy of the curved surface shape of the optical element of the front windshield has a decisive influence on the quality of the final projected image.

[0003] Therefore, the glass manufacturer must detect the curved surface shape of the front windshield with high precision during the production process. The traditional detection method involves fixing the glass to be detected on a detection tool, and the fixing process usually includes support, centering and clamping. However, the front windshield is a large-size thin-walled part with semi-flexible characteristics. When subjected to the positioning pressure applied by the clamping mechanism, the glass itself will inevitably produce a certain degree of elastic deformation. The deformation introduced by the clamping force during the measurement process causes the data obtained by the surface shape acquisition system to differ from the true surface shape of the glass in the free state. This may lead to false detection and cause unnecessary rework, or it may lead to subsequent process adjustments, resulting in serious waste of resources. SUMMARY

[0004] The present disclosure provides a surface shape determination method, device, equipment and computer storage medium, which can solve the technical problem of insufficient surface shape detection precision due to the pressure of centering and clamping in the prior art.

[0005] The technical solution of the present disclosure is implemented as follows: In a first aspect, the present disclosure provides a surface shape determination method, comprising: obtaining an actual clamping pressure of a to-be-detected optical element under the action of an element fixing mechanism, and an initial surface shape point cloud under the actual clamping pressure; determining a position offset of at least one point cloud point in the initial surface shape point cloud based on the actual clamping pressure and a preset deformation relationship, wherein the deformation relationship represents the deformation amount of at least one point on the to-be-detected optical element under different clamping pressures; applying the position offset to the at least one point cloud point in the initial surface shape point cloud to generate a compensated surface shape.

[0006] In a second aspect, the present disclosure provides a surface shape determination device, comprising: an element fixing mechanism configured to clamp a to-be-detected optical element; a pressure acquisition mechanism configured to acquire an actual clamping pressure of the optical element under application of the element fixing mechanism; a controller configured to determine a position offset of at least one point cloud point in the initial surface profile point cloud based on the actual clamping pressure and a preset deformation relationship; and apply the position offset to the at least one point cloud point in the initial surface profile point cloud to generate a compensated surface profile.

[0007] In a third aspect, the present disclosure provides an electronic device, which includes a processor and a memory storing computer executable instructions, the computer executable instructions being executed by the processor to cause the processor to execute the surface profile determination method of the first aspect.

[0008] In a fourth aspect, the present disclosure provides a computer readable storage medium storing a computer program, the computer program being executed by a processor to implement the surface profile determination method of the first aspect.

[0009] The present disclosure provides a surface profile determination method, device, equipment and computer storage medium. In the measurement process, the actual clamping pressure of the optical element under the application of the centering and clamping mechanism is acquired, and the initial surface profile point cloud under the actual clamping pressure is acquired. Then, the position offset of at least one point cloud point in the initial surface profile point cloud is determined based on the actual clamping pressure and a preset deformation relationship. Finally, the position offset is applied to the at least one point cloud point in the initial surface profile point cloud to generate a compensated surface profile. The compensated surface profile is compared with the design surface profile, which improves the detection accuracy and reduces the misjudgment rate. BRIEF DESCRIPTION OF DRAWINGS

[0010] Figure 1 The hardware system of the high-precision surface profile measurement system of an embodiment of the present disclosure is shown in the overall schematic diagram.

[0011] Figure 2 The structure of the glass to be measured provided by the present disclosure is shown in the schematic diagram.

[0012] Figure 3 The flowchart of the surface profile determination method provided by the present disclosure is shown in the flowchart.

[0013] Figure 4 The flowchart of the deformation relationship provided by the present disclosure is shown in the flowchart.

[0014] Figure 5 The flowchart of another surface profile determination method provided by the present disclosure is shown in the flowchart.

[0015] Figure 6 The schematic diagram of the deformation surface provided by the present disclosure is shown in the schematic diagram.

[0016] Figure 7 A schematic diagram of an electronic device is provided for the present disclosure. DETAILED DESCRIPTION

[0017] The technical solutions in the present disclosure will be described clearly and completely in combination with the drawings in the present disclosure.

[0018] Figure 1 The overall schematic diagram of the hardware system of the high-precision surface shape measurement system of one embodiment of the present disclosure is shown. The system can be used to perform the measurement method described in subsequent embodiments. The system can also be regarded as one specific embodiment of the surface shape determination device described in the present disclosure.

[0019] As Figure 1 shown, the system can include an element fixing mechanism 10, a surface shape acquisition system 20, a controller 30, and an optional to-be-measured region calibration system 40 in some embodiments.

[0020] The element fixing mechanism 10 is used to physically position the to-be-measured optical element, such as the to-be-measured glass 101, according to a preset detection state. The element fixing mechanism 10 can include the to-be-measured glass 101, a support mechanism 102, a centering clamping mechanism 103, and a key additional component pressure acquisition mechanism 104.

[0021] The to-be-measured glass 101 is usually a curved automobile front windshield glass in HUD applications. As Figure 2 shown, the to-be-measured glass 101 has its specific orientation terms, such as the lower edge 1021 and the X direction. For example, the to-be-measured glass 101 has semi-flexibility, and its material properties, such as the Young's modulus of about 70 GPa and the Poisson's ratio of about 0.22, make it also produce micron-level deformation when subjected to a small force.

[0022] The support mechanism 102 is used to support the to-be-measured glass 101 at multiple design points to make it conform to the detection state.

[0023] The support mechanism 102 uses point support for the glass. For example, three support points can be used to uniquely determine a plane, thereby achieving stable support. In some embodiments, in order to prevent the to-be-measured glass 101 from sagging between the support points due to its own weight, more than three support points can be used, and the distance between the support points is ensured to meet the requirement of rigid connection between two points.

[0024] In some examples, the force direction of the support point is along the normal direction of the point on the glass. The tangential stress introduced by the support force is minimized to ensure that the support force is mainly used to counteract the gravity and reduce unnecessary distortion.

[0025] Since the initial pose of the glass 101 is not fixed when it is placed on the support mechanism 102, the centering and clamping mechanism 103 is needed to fix the pose of the glass 101 and make it in a known state.

[0026] For the limiting in Y direction / Z direction, as shown in Figure 2 , a set of physical limiting tooling can be designed by taking the lower edge 1021 of the glass as a reference. When the glass 101 is placed at a certain angle, its weight will make its lower edge 1021 lean on the limiting tooling, thereby completing the limiting in Y direction and Z direction.

[0027] For the clamping in X direction, as shown in Figure 2 , a movable centering and clamping mechanism 103 is designed on both sides of the glass 101 in X direction. For example, it can be composed of a linear actuator driven by a pneumatic cylinder or a servo motor. When the glass 101 is placed, the centering and clamping mechanism 103 is in an open position; after the placement is completed, the control system controls the centering and clamping mechanism 103 to move to a working position.

[0028] The two sides in X direction are synchronously moved. The synchronous movement can ensure that the center line of the glass 101 is pushed to a known X direction center position while it is clamped, thereby realizing the functions of centering and clamping.

[0029] The pressure acquisition mechanism 104 functions to acquire the pressure value of the glass during the centering and clamping.

[0030] In a specific embodiment, the pressure acquisition mechanism 104 can be a pressure sensor fixed on the clamping head of the centering and clamping mechanism 103 in X direction, i.e. the sensing surface of the pressure sensor directly or indirectly contacts the edge of the glass 101, and the sensor type can adopt various types of force sensors, which will not be described in detail in the present disclosure.

[0031] When the centering and clamping mechanism 103 moves, the pressure sensor will first contact the glass 101 and generate a pressure signal. When the centering and clamping mechanism 103 moves to a preset working position, the locking position, the reading displayed on the pressure sensor at this time is the measured pressure value P1 of the glass 101 in the current state. The measured pressure value P1 will be acquired by the pressure sensor 104.

[0032] The surface profile acquisition system 20 acquires the surface profile data of the glass in the current state by scanning or visual means. The acquired surface profile data exists in the form of point cloud. The point cloud refers to a collection of a large number of points on the target surface in a three-dimensional coordinate system, each point containing at least (x, y, z) coordinate information.

[0033] In some examples, the above-mentioned surface profile acquisition system 20 can be a structured light scanning system, which can include at least one digital projector and at least one high-resolution camera. The digital projector projects a series of specially coded patterns onto the surface of the glass 101 to be measured. Since the glass 101 to be measured is curved, the high-resolution camera will capture the pattern modulated by the curved surface. By analyzing the degree of distortion of the pattern, the three-dimensional coordinates (x, y, z) of millions of points in the field of view of the camera can be calculated using the principle of triangulation, thereby generating high-density surface profile point cloud data.

[0034] In some examples, the above-mentioned surface profile acquisition system 20 can also be a laser line scanning system, which can include a laser line emitter and a camera. The laser emitter projects a laser line onto the surface of the glass 101 to be measured. The camera captures the laser line from a certain angle. According to the position of the laser line on the camera imaging instrument, the (x, y, z) coordinates of all points on the line can also be calculated using the principle of triangulation. By moving the laser scanning head through a linear moving platform, the laser line is scanned across the entire measurement area, thereby building a complete surface profile point cloud data row by row.

[0035] The specific structure type of the surface profile acquisition system 20 can also be customized according to user requirements, which will not be described here.

[0036] The controller 30 can include an impatient industrial computer, a server, or a dedicated embedded system. At the hardware level, the controller 30 is responsible for connecting the pressure sensor 104 to obtain the measured pressure value P1. Connect the surface profile acquisition system 20 to obtain the initial surface profile point cloud. In some embodiments, the element fixing mechanism 10 and the measurement area calibration system 40 are connected and controlled.

[0037] In many practical applications, it is not necessary to measure the entire surface of the glass 101 to be measured, but only a part of it. At this time, the measurement area calibration system 40 is needed. The measurement area calibration system 40 identifies the measurement area in the measurement environment according to the design requirements. The measurement area calibration system 40 can be a laser projector. It accurately draws the outline of the measurement area on the surface of the glass 101 to be measured according to the design file stored in the controller 30. The surface profile acquisition system 20 can scan according to this outline. The measurement area calibration system 40 can also be integrated into the surface profile acquisition system 20. For example, the surface profile acquisition system 20 first performs a rough scan on the glass 101 to be measured, and the controller 30 automatically aligns the rough scan result with the design model, thereby marking the position of the measurement area in the spatial coordinate system involved in the algorithm. The surface profile acquisition system 20 is guided to only collect the surface profile data of the area, improving the collection efficiency. When subsequent surface compensation is performed, priority is given to matching the marked points, i.e., accurately matching the collected point cloud points with the corresponding points in the simulation, and then compensating the deformation caused by the pressure to the corresponding points.

[0038] Figure 3 A main flowchart of a surface determination method according to an embodiment of the present disclosure. The method can be performed by the system shown in Figure 1 , in particular the controller 30 therein.

[0039] As shown in Figure 3 , the method can include the following steps S310 to S330.

[0040] In step S310, an actual clamping pressure of the optical element to be measured under the action of the element fixing mechanism is obtained, and an initial surface point cloud under the actual clamping pressure is obtained.

[0041] In some example embodiments of the present disclosure, an automated mechanical arm places the glass to be measured 101 onto the support mechanism 102, and then starts the centering and clamping mechanism 103. The centering and clamping mechanism 103 moves synchronously to clamp and fix the glass 101 in a preset measurement pose. Then, the actual clamping pressure and the initial surface point cloud are obtained. When the glass to be measured 101 is fixed by the centering and clamping mechanism 103, a pressure sensor integrated with the centering and clamping mechanism 103 measures and outputs a pressure reading in real time. This reading is the actual clamping pressure P1. At the same time, when the glass 101 is kept in the clamped state at the actual clamping pressure P1, the surface acquisition system 20 scans the to-be-measured area of the glass 101. The data output by the surface acquisition system 20 is the initial surface point cloud. It should be emphasized that this initial surface point cloud is the surface data of the glass 101 under the pressure deformation state, and it does not represent the true surface of the glass.

[0042] In step S320, based on the actual clamping pressure and the preset deformation relationship, a position offset amount of at least one point cloud point in the initial surface point cloud is determined.

[0043] The deformation relationship represents the deformation amount of at least one point on the optical element to be measured under different clamping pressures.

[0044] In some examples, the preset deformation relationship can be obtained first. The obtaining of the deformation relationship can be completed offline, i.e., before the actual measurement starts. The preset deformation relationship represents the deformation amount of a point on the optical element to be measured 101 when it is subjected to different clamping pressures. The deformation relationship can be obtained by simulation in a design software. The deformation relationship can have two main forms, such as a deformation curve and a surface profile.

[0045] The deformation curve is a one-dimensional function relationship between the pressure value and the deformation amount for a certain key point. The deformation surface is a three-dimensional function relationship between the pressure value and the deformation amount of any coordinate on the glass surface. In the process of obtaining the deformation relationship, a design pressure value P is usually determined. The design pressure value P is a standard pressure value obtained by superimposing the deformation curve and the displacement change curve, which represents the ideal pressure state that minimizes the glass deformation amount and simultaneously enables uniform displacement.

[0046] In determining the position offset, the input of the controller 30 is the preset deformation relationship, the actual clamping pressure P1, and the initial face shape point cloud. The output is the position offset. The offset represents the deformation amount of each point in the initial face shape point cloud due to the pressure P1.

[0047] In step S330, the position offset is applied to at least one point cloud point in the initial face shape point cloud to generate a compensated face shape.

[0048] In some example embodiments of the present disclosure, the position offset is applied to the initial face shape point cloud. The controller can perform coordinate adjustment or data compensation on the initial face shape point cloud, for example, for any point in the initial face shape point cloud, the corresponding position offset is calculated, and then the coordinates of the point are adjusted based on the position offset.

[0049] After the adjustment of the position offset is completed, a compensated face shape is generated. After the compensation algorithm is applied to all point cloud points in the initial face shape point cloud, a new point cloud set is formed, which constitutes the compensated face shape. The compensated face shape theoretically represents the true face shape of the glass 101 to be tested in a free state after the influence of the P1 pressure is eliminated.

[0050] After obtaining the compensated face shape, the controller 30 compares it with the stored standard design face shape data. According to whether the deviation of the comparison is within a reasonable range, it is finally determined whether the glass to be tested meets the design requirements.

[0051] The comparison of the present embodiment is between the compensated face shape and the design face shape. Since the compensated face shape is similar to the true face shape, the comparison benchmark of the present embodiment is closer to the true situation, thereby improving the face shape detection accuracy. Due to the improved accuracy, the misjudgment rate caused by measurement errors is reduced. Due to the reduced misjudgment rate, unnecessary rework actions are reduced, thereby reducing the resource waste caused by rework.

[0052] In some examples, the following is referred to Figure 4 The process of generating the above deformation relationship is explained in detail.

[0053] In step S401, a finite element model of the optical element to be tested is constructed.

[0054] First, import the precise 3D model of the glass 101 under test. Assign precise material properties to the model. For example, define its Young's modulus, Poisson's ratio and density for an automotive glass. Then perform meshing, which discretizes the continuous geometry model into a collection of finite elements and nodes. The density of the mesh affects the accuracy and time of the computation. Generally, finer mesh is used in the regions of interest and the regions where forces / constraints are applied.

[0055] In step S402, apply the simulated boundary conditions and loads.

[0056] Apply displacement constraints on the nodes corresponding to the physical support points 102. Apply parametric pressure loads on the nodes corresponding to the locations of the centering clamping mechanisms 103. That is, simulate the pressure.

[0057] In step S403, perform the simulation process to obtain a plurality of sets of deformation data.

[0058] The controller 30 performs a parametric sweep or load step analysis. Iteratively change the value of the simulated pressure, for example, from 0 N, in steps of 0.5 N, up to 5.0 N, for a total of 11 load steps. At each load step, calculate the displacement and strain of all nodes on the model. Then extract the required data from the simulation results to form a collection of a plurality of sets of deformation data.

[0059] If the goal is to establish a deformation curve, extract the Z-direction displacement of a certain key point to form a two-dimensional data table. If the goal is to establish a deformation surface, extract the coordinates of all points in the region under test and their Z-direction displacements under that pressure to form a strain point cloud map.

[0060] In step S404, generate the deformation relationship through a curve fitting algorithm.

[0061] The controller 30 processes the obtained plurality of sets of deformation data. The goal of the processing is to find a mathematical function that best passes through these discrete data points. Specifically, the least squares method can be followed to obtain the mathematical function. Validate the fitted mathematical function against the curve and tune it to find a balance between the fitting accuracy and the complexity of the model. The final generated deformation relationship is stored in the controller 30 for subsequent calls.

[0062] When determining the offset based on the deformation relationship, the design pressure value P can be determined first. The design pressure value P is determined by superimposing the deformation curve and the displacement change curve. At the pressure P, the glass 101 under test is stably clamped, and at the same time its own deformation reaches the minimum deformation state. This P value is considered as the standard or ideal clamping force. The P value is stored in the controller 30.

[0063] The following will be described in conjunction with Figure 5The compensation process based on the deformation relationship as a deformation curve is described in detail.

[0064] In step S501, the measured pressure value and the initial surface profile point cloud are obtained.

[0065] The controller 30 receives the measured pressure value P1 from the pressure sensor and the initial surface profile point cloud from the surface profile acquisition system 20.

[0066] In step S502, the pressure difference is calculated.

[0067] The controller 30 reads the design pressure value P from the memory and calculates the pressure difference ΔP = P1 - P, which represents the deviation of the actual clamping force from the ideal clamping force. The goal of this embodiment is to calculate and compensate for the additional deformation caused by ΔP.

[0068] In step S503, the position offset is calculated.

[0069] The controller 30 first obtains the stored deformation curve function y = f(P). Then it calculates the first derivative function of this function: f'(P) = dy / dP. The controller 30 substitutes the measured pressure value P1 into the derivative function to calculate the slope at the P1 point: k = f'(P1). The position offset can be approximately obtained by multiplying the slope k at this point by the pressure difference ΔP.

[0070] In some examples, the positive or negative of the corresponding point offset can be determined by judging the relationship between k and 0. Example: if k = f'(P1) is positive, it means that the larger the pressure, the larger the deformation. If P1 > P, then ΔP > 0, and the position offset is positive. This means that the "actual deformation" is greater than the "standard deformation". If P1 < P, then ΔP < 0, and the position offset is negative. This means that the actual deformation is less than the standard deformation.

[0071] Specifically, when pressure is applied in the glass X direction, each point on the inner and outer surfaces of the glass is affected by bending stress, which causes a compressive linear strain on the inner side of the glass. This can be understood as the radius of curvature of the corresponding point on the inner surface of the glass becoming smaller, that is, the vector module in the direction of the normal line of the point is becoming smaller. The position offset calculated in this embodiment is a quantification of this smaller value.

[0072] In step S504, the point cloud data is compensated.

[0073] The controller 30 iterates through each point cloud point in the initial surface profile point cloud. For the i-th point cloud point, the controller 30 applies the position offset calculated in step S503 to the point.

[0074] In step S505, the compensated surface profile is generated.

[0075] The geometry of all compensated point cloud points is taken as the above-mentioned compensated face type.

[0076] In practice, with reference to Figure 6 , the clamping force is at the edge in the X direction, while the region to be measured can be in the center of the glass, and the deformation is likely to be non-uniform in space. Therefore, the above deformation relationship can be described in the form of a deformation surface. At this time, when determining the above position offset, a dedicated position offset is calculated for each point in the initial face type point cloud. The deformation surface stored in the 3D-LUT is discrete. Based on this, an interpolation-based method is used to determine the position of each point in the grid point of the LUT.

[0077] The processing method of other parts is the same as the above-mentioned deformation curve part, and will not be repeated here.

[0078] In some detection tasks, only the specific functional region on the glass 101 to be measured, such as the HUD light transmission reflection region, may be of interest, rather than the entire face type of the windshield. If the face type acquisition system 20 still acquires full-view data, a large amount of redundant point cloud data will be generated, increasing the acquisition time, data transmission bandwidth, and subsequent processing time, and reducing the detection beat.

[0079] A region to be measured can be calibrated before the initial face type point cloud is acquired. The region to be measured calibration system 40 is activated. For example, the region to be measured calibration system 40 is a laser projector. The controller 30 reads the contour data of the HUD light transmission reflection region from the model. The controller 30 controls the region to be measured calibration system 40 to accurately project the contour onto the surface of the positioned glass 101 to be measured, forming a visible region to be measured boundary.

[0080] The face type acquisition system 20 is configured to only acquire and / or output point cloud data located inside the calibrated contour. In the case of a CMM or mechanical arm scanning, the motion path of the system 20 is limited within the calibrated region. If the system 20 is a full-view scanner, it still acquires the full view, but the controller 30 immediately uses the calibrated contour data as a mask to crop out the point cloud data outside the contour, and only retains the point cloud data within the region to be measured.

[0081] The controller 30 only performs the compensation algorithm on this smaller initial face type point cloud subset. Preferentially or centrally matching and interpolating these points with the corresponding simulated nodes of the HUD region in the stored deformation surface, thereby improving the efficiency and robustness of the compensation calculation.

[0082] By introducing the to-be-measured region calibration system 40, the embodiment significantly reduces the amount of data that needs to be collected and processed without losing the compensation accuracy of the target region. The scanning time and data transmission time are reduced. The processing speed is accelerated, and the file size of the initial surface point cloud and the compensated surface is reduced.

[0083] Reference is made to Figure 7 , which shows a structural block diagram of a computing device provided by an example embodiment of the present disclosure. In some examples, the computing device 70 can be at least one of a smartphone, a smart watch, a desktop computer, a laptop computer, a virtual reality terminal, an augmented reality terminal, a wireless terminal, and a laptop computer. The computing device 70 has a communication function and can access a wired network or a wireless network. The computing device 70 can generally refer to one of a plurality of terminals, and those skilled in the art can know that the number of terminals can be more or less.

[0084] As shown in Figure 7 , the computing device in the present disclosure can include one or more of the following components: a processor 710 and a memory 720.

[0085] Optionally, the processor 710 connects various parts within the entire computing device through various interfaces and lines, and performs various functions of the computing device and processes data by running or executing instructions, programs, code sets or instruction sets stored in the memory 720, and calling data stored in the memory 720. Optionally, the processor 710 can be implemented in at least one of the following hardware forms: digital signal processing (Digital Signal Processing, DSP), field programmable gate array (Field-Programmable Gate Array, FPGA), programmable logic array (Programmable Logic Array, PLA). The processor 710 can integrate one or a combination of central processing units (Central Processing Unit, CPU), graphics processing units (Graphics Processing Unit, GPU), neural network processing units (Neural-network Processing Unit, NPU), and baseband chips. Among them, the CPU mainly processes the operating system, user interface and application program, etc.; the GPU is responsible for rendering and drawing the content to be displayed on the touch display screen; the NPU is used to realize the artificial intelligence (Artificial Intelligence, AI) function; the baseband chip is used to process wireless communication. It can be understood that the above-mentioned baseband chip can also not be integrated into the processor 710, but be realized by a separate chip.

[0086] The memory 720 can include a Random Access Memory (RAM) and can also include a Read-Only Memory (ROM). Optionally, the memory 720 includes a non-transitory computer-readable storage medium. The memory 720 can be used to store instructions, programs, codes, code sets, or instruction sets. The memory 720 can include a program storage area and a data storage area, where the program storage area can store instructions for implementing an operating system, instructions for at least one function (such as a touch function, a sound playing function, an image playing function, etc.), instructions for implementing the above various method embodiments, etc., and the data storage area can store data created based on use of the computing device, etc.

[0087] In addition, those skilled in the art can understand that the structure of the computing device shown in the above-described figures does not constitute a limitation on the computing device, and the computing device can include more or fewer components than those shown in the figures, or combine certain components, or different component arrangements. For example, the computing device also includes a display screen, a camera assembly, a microphone, a speaker, a radio frequency circuit, an input unit, a sensor (such as an acceleration sensor, an angular velocity sensor, a light sensor, etc.), an audio circuit, a WiFi module, a power supply, a Bluetooth module, etc., which are not described here in detail.

[0088] The present disclosure also provides a computer-readable storage medium storing at least one instruction for being executed by a processor to implement the face type determination method according to the above various embodiments.

[0089] The present disclosure also provides a computer program product including computer instructions stored in a computer-readable storage medium; a processor of a computing device reads the computer instructions from the computer-readable storage medium, and the processor executes the computer instructions to cause the computing device to perform the face type determination method according to the above various embodiments.

[0090] Those skilled in the art should be aware that, in one or more examples described above, the functions described in the present disclosure can be implemented in hardware, software, firmware, or any combination thereof. When implemented in software, the functions can be stored in a computer-readable medium or transmitted as one or more instructions or codes on a computer-readable medium. The computer-readable medium includes a computer storage medium and a communication medium, where the communication medium includes any medium that facilitates transfer of a computer program from one place to another. The storage medium can be any available medium accessible by a general-purpose or special-purpose computer.

[0091] It should be noted that the technical solutions disclosed in the present disclosure can be combined arbitrarily without conflict.

[0092] The above merely provides a specific implementation of the present application, but the protection scope of the present application is not limited thereto, and any person skilled in the art can easily think of changes or replacements within the technical range disclosed in the present application, which should be covered in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A face shape determination method characterized by comprising: The method comprises: obtaining an actual clamping pressure of a to-be-tested optical element under the action of an element fixing mechanism, and an initial surface type point cloud under the actual clamping pressure; determining a position offset of at least one point cloud point in the initial surface type point cloud based on the actual clamping pressure and a preset deformation relationship, wherein the deformation relationship represents a deformation amount of at least one point on the to-be-tested optical element under different clamping pressures; applying the position offset to the at least one point cloud point in the initial surface type point cloud to generate a compensated surface type.

2. The face shape determination method according to claim 1, wherein The method further comprises: obtaining a plurality of sets of deformation amount data of the to-be-tested optical element at the at least one point cloud point under a plurality of simulated pressures; generating the deformation relationship through curve fitting based on the plurality of sets of deformation amount data.

3. The face shape determination method according to claim 1, wherein The deformation relationship comprises a design pressure value corresponding to a minimum deformation state of the to-be-tested optical element; The determination of the position offset of the at least one point cloud point in the initial surface type point cloud comprises: calculating the position offset based on a pressure difference between the actual clamping pressure and the design pressure value.

4. The face shape determination method according to claim 3, wherein The deformation relationship is represented by a deformation curve function representing the relationship between pressure and deformation amount; The calculation of the position offset comprises: determining a first derivative value of the deformation curve function at the actual clamping pressure; and determining the position offset based on the first derivative value. The deformation relationship is a deformation surface representing the relationship among surface coordinates, pressure, and deformation amount on the surface of the to-be-tested optical element; 5. The face shape determination method according to claim 3, wherein The determination of the position offset comprises: obtaining surface coordinates of a point cloud point in the initial surface type point cloud on the surface of the to-be-tested optical element; and obtaining the position offset of the point cloud point from the deformation surface based on the surface coordinates and the actual clamping pressure. The method further comprises: calibrating a to-be-tested region on the to-be-tested optical element before obtaining the initial surface type point cloud; 6. The face shape determination method according to claim 1, wherein obtaining a surface type point cloud of the to-be-tested region. The device comprises: an element fixing mechanism for clamping a to-be-tested optical element; 7. A face shape determining apparatus, characterized by comprising: a pressure obtaining mechanism for obtaining an actual clamping pressure of the to-be-tested optical element under the action of the element fixing mechanism; a controller for determining a position offset of at least one point cloud point in an initial surface type point cloud of the to-be-tested optical element based on the actual clamping pressure and a preset deformation relationship; and applying the position offset to the at least one point cloud point in the initial surface type point cloud to generate a compensated surface type. The device further comprises: a surface type acquisition system for obtaining the initial surface type point cloud. The pressure obtaining mechanism comprises a pressure sensor fixed between the element fixing mechanism and the to-be-tested optical element for obtaining the actual clamping pressure.

8. The face shape determination apparatus according to claim 7, wherein The electronic device comprises a processor and a memory, wherein the memory stores computer executable instructions, and the processor executes the computer executable instructions to perform the surface type determination method according to any one of claims 1 to 6. ​ 9. The face shape determination apparatus according to claim 7, wherein ​ 10. An electronic device for face type determination, comprising: ​ 11. A computer readable storage medium, characterized in that, The computer readable storage medium stores a computer program, and the computer program is executed by the processor to implement the face shape determination method in any one of claims 1 to 6.

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