Component surface high-precision three-dimensional contour weak rigidity detection system and method

Abstract

The invention relates to the technical field of contour detection, in particular to a component surface high-precision three-dimensional contour weak rigidity detection system and method. The component surface high-precision three-dimensional contour weak rigidity detection system comprises a positioning mechanism, a measuring head mechanism and a movement mechanism, the measuring head mechanism comprises a measuring rod, one end of the measuring rod is fixed to a center measuring base, the center measuring base is sleeved with a shell linked with the movement mechanism, and the shell is connected with the movement mechanism. The center measuring seat is connected and supported in the shell through elastic pieces, the elastic pieces comprise an X-direction elastic piece, a Y-direction elastic piece and a Z-direction elastic piece which are symmetrically arranged in pairs, and at least one non-contact displacement sensor is arranged in each of three orthogonal directions of the center measuring seat. And a temperature sensor and a humidity sensor are arranged on the shell. The method has the advantages that the performance and reliability of a detection system can be remarkably improved, and high-precision and high-accuracy measurement results can be obtained.

Description

Technical Field

[0001] The present invention relates to the technical field of contour detection, and particularly relates to a high-precision three-dimensional contour weak stiffness detection system and method for the surface of a component. Background Art

[0002] With the development of high-tech industries and advanced manufacturing, the precision and structural complexity of components required in fields such as aerospace, semiconductors, and optoelectronics are increasing day by day. Therefore, the measurement requirements for these components are also increasing. Precision measurement of the three-dimensional contour of the component surface is an important part of the micro-nano measurement field.

[0003] Currently, the main devices for precision measurement of the component surface contour are atomic force microscopes (AFMs), scanning electron microscopes (SEMs), ultra-high-precision three-dimensional measuring instruments (UA3Ps), etc. Among them, AFMs and SEMs can accurately measure the surface topography of components. However, due to the small measurement range and small longitudinal range of AFMs and SEMs, it is difficult to measure components with large surface undulations or large sizes. Although the UA3P can achieve precision measurement of the three-dimensional contour of the component surface, it can only measure the surface topography of simple structures and is difficult to measure complex structures.

[0004] On the other hand, the probe sensing systems mainly include optical systems, capacitive sensing systems, grating measurement systems, etc. Optical systems (such as the solutions disclosed in patents with application numbers 202410931158.4, 202311224536.7, etc.) are greatly affected by environmental changes. Especially, temperature changes and air flow affect the air density, change the refractive index of the air, and then cause signal fluctuations in the optical system, reducing the precision of probe sensing. For capacitive sensing systems, the thermal deformation of their mechanical structures has a great impact on the signals of the sensing system, thereby reducing the overall measurement precision of the probe. For grating measurement systems, such as the solution disclosed in the patent with application number 202010685064.5, although it can perform micro-force detection, its structure is relatively complex, the contact force of the probe still reaches 30 gf - 100 gf, which has a great impact on the detection results. At the same time, since an additional turntable needs to be set up to detect the side contour, the detection progress will be further reduced and it cannot be used for precision measurement of the three-dimensional contour of the component surface. Summary of the Invention

[0005] The purpose of the present invention is to provide a high-precision three-dimensional contour weak stiffness detection system for the surface of a component that can perform three-dimensional contour detection on the surface of the component and has higher detection result precision.

[0006] To achieve the above object, the present invention adopts a high-precision three-dimensional contour weak stiffness detection system for the surface of a component, which includes a positioning mechanism for positioning and fixing the component to be detected, a probe mechanism, and a motion mechanism for driving the probe mechanism to move. The probe mechanism includes a probe rod for contacting the component to be detected. One end of the probe rod is fixed to a central measuring seat. An outer shell linked with the motion mechanism is sleeved outside the central measuring seat. The central measuring seat is connected and supported inside the outer shell through an elastic member. The elastic member includes X-direction elastic members, Y-direction elastic members, and Z-direction elastic members that are symmetrically arranged in pairs. The X-direction elastic members, Y-direction elastic members, and Z-direction elastic members are orthogonally arranged in pairs. At least one non-contact displacement sensor fixed to the outer shell is provided in each of the three orthogonal directions of the central measuring seat. A temperature sensor and a humidity sensor for detecting the air temperature and humidity between the central measuring seat and the outer shell are provided on the outer shell.

[0007] The probe mechanism of the present invention is connected and supported inside the central measuring seat through an elastic member, and the X-direction elastic members, Y-direction elastic members, and Z-direction elastic members are orthogonally arranged in pairs, enabling the central measuring seat fixed with the probe rod to move flexibly in three orthogonal directions, thereby expanding the measurement range and meeting the measurement requirements of components with large surface undulations or large sizes; due to the multi-directional elastic support of the elastic member, the probe mechanism can contact and adapt to the contours of complex structures more flexibly. With the drive of the existing motion mechanism, three-dimensional contour detection can be performed on the surface of components with complex structures.

[0008] The present invention adopts non-contact displacement sensors, avoiding signal fluctuations caused by changes in air density in the optical system and improving the stability of probe sensing. By connecting and supporting the central measuring seat and the outer shell through an elastic member, the influence of thermal deformation of the mechanical structure on the signal of the sensing system is reduced, and the overall measurement accuracy of the probe mechanism is improved. The design of the probe mechanism of the present invention does not require an additional turntable to detect the side contour, simplifying the structure; and the probe rod is fixed to the central measuring seat, and the central measuring seat is connected and supported inside the outer shell through an elastic member. With non-contact displacement sensors, the contact force of the probe can be made smaller, even reaching the micro-newton level, realizing weak stiffness contact between the end of the probe rod and the component to be detected, reducing the influence on the detection result, and being able to be used for high-precision measurement of the three-dimensional contour of the component surface, improving the accuracy of the detection result.

[0009] Meanwhile, the temperature sensor and humidity sensor set on the outer shell can monitor the air temperature and humidity between the central measuring seat and the outer shell in real time, providing a basis for environmental compensation and accuracy calibration during the measurement process, and further improving the accuracy of the detection results. After the end of the measuring rod contacts the component and generates displacements in three-dimensional directions, under the transmission of the elastic member, the central measuring seat will also generate displacements in three-dimensional directions. By pre-testing and recording, the displacement transfer matrix between the two displacements is obtained. The displacement of the central measuring seat is obtained through a non-contact displacement sensor. Thus, when the displacement data of the probe mechanism driven by the motion mechanism is determined, through displacement compensation, the displacement data of the end of the measuring rod during actual detection can be obtained, and the final measurement result can be obtained.

[0010] The system of the present invention designs a three-dimensional symmetric elastic member structure to offset the deformation force caused by the thermal expansion of the elastic member structure, reduce the displacement of the central measuring seat, and thus reduce the signal drift of the sensor. Taking the elastic members in the X direction as an example, the thermal deformations ɛ1 = αΔT and ɛ2 = αΔT generated by the two elastic members under the influence of the temperature change ΔT, where α is the coefficient of thermal expansion. The contact stresses generated by the thermal deformations of the two elastic members are F1 = Kɛ1 and F2 = Keq*ɛ2 respectively, and Keq is the equivalent stiffness of the mechanical structure. The two are equal in magnitude and opposite in direction, so the resultant force F = F1 + F2 = 0 received at the central measuring seat. Therefore, the signal change of the non-contact displacement sensor is zero, and the deformation force caused by the thermal expansion of the elastic member can be offset through the three-dimensional symmetric structure.

[0011] Among them, the system or the outer shell of the present invention should be enclosed to prevent air disturbance to further improve the accuracy of the measurement results. Among them, the non-contact displacement sensor of the present invention can adopt a capacitive displacement sensor, a confocal probe, etc. Among them, the elastic member can adopt a spring with a lower stiffness level, and the positioning and fixing of the elastic member can be carried out through the pre-tightening force of the elastic member and the circular grooves reserved on the outer shell and the central measuring seat.

[0012] Preferably, the elastic member is sleeved outside the non-contact displacement sensor.

[0013] The elastic member is sleeved outside the non-contact displacement sensor, which not only facilitates the installation and fixing of the non-contact displacement sensor and the elastic member, but also enables the two not to interfere with each other, and makes the non-contact displacement sensor closer to the center of the central measuring seat surface.

[0014] Preferably, some components of the central measuring seat, the outer shell and the non-contact displacement sensor are made of materials with low coefficients of thermal expansion.

[0015] Among them, the coefficient of thermal expansion of the present invention can be much smaller than that of the structural materials (such as aluminum alloy) used in the conventional three-dimensional profile detection system. For example, the coefficient of thermal expansion of the material with a low coefficient of thermal expansion of the present invention can be only 1.2x10-6 The thermal expansion coefficient of conventional aluminum alloys can be one twentieth of that per degree Celsius. This invention reduces the thermal expansion of the entire probe mechanism by using low-expansion materials such as invar alloys or conductively coated glass-ceramics, thereby reducing sensor signal drift and improving detection accuracy, resulting in highly accurate test results.

[0016] Preferably, the housing is provided with a matching hole for the non-contact displacement sensor portion to pass through, and the non-contact displacement sensor portion extends to the outside of the housing.

[0017] A smaller housing is relatively less affected by changes in external ambient temperature, and its internal temperature distribution is more uniform; a smaller housing has a smaller mass, and the driving force required for the motion mechanism is smaller. The motion mechanism can drive the probe mechanism to move and adjust more quickly, thereby improving the response speed and dynamic performance of the entire detection system; the lag effect caused by its inertia is also smaller, so that the probe mechanism can follow the instructions of the motion mechanism to change position more promptly, thereby improving the real-time and coordination of the detection system; at the same time, it also facilitates the wiring or signal transmission of the non-contact displacement sensor.

[0018] Preferably, the measuring rod is arranged along the Z direction and is coaxial with the Z-direction elastic member, the measuring rod is connected below the central measuring seat, the outer shell includes a shell and a lower cover, and the lower cover is sleeved outside the measuring rod.

[0019] The measuring rod is arranged along the Z direction (vertically) and coaxial with the Z-direction elastic member. When driven by the motion mechanism, it can avoid additional bending moments and shear forces caused by eccentricity as much as possible, thereby improving the accuracy of measuring the displacement of the measuring rod. The non-contact displacement sensor can more accurately measure tiny displacement changes of the measuring rod, thereby improving the measurement accuracy of the three-dimensional contour of the component surface by the entire detection system.

[0020] Preferably, a measuring ball is provided at one end of the measuring rod away from the central measuring seat.

[0021] The stylus ball has a smaller contact area and lower contact stiffness, enabling more precise positioning of the contact point when in contact with the component being measured, helping to improve measurement accuracy and resolution. Furthermore, the stylus ball can better adapt to the complex contours and curvature variations of the component being measured, making it particularly suitable for inspecting components with complex geometries or uneven surfaces, enhancing measurement flexibility and adaptability.

[0022] The present invention discloses a measurement method using the above-mentioned component surface high-precision three-dimensional profile weak stiffness detection system, comprising the following steps: S1. Establishing a probe displacement signal-wet temperature model; S2. According to the probe displacement signal-temperature and humidity model obtained in step S1 and the real-time acquisition signals of the temperature sensor and the humidity sensor, calculate the signal fluctuation component generated by the non-contact displacement sensor due to environmental temperature and humidity changes, and perform online error compensation on the value detected by the non-contact displacement sensor; S3. Conduct a three-dimensional displacement calibration experiment on the component to be detected, obtain the displacement values S measured by all non-contact displacement sensors under the displacements of the central measuring seat in the X, Y, and Z directions, and establish a displacement transfer formula between the displacement of the probe end and the displacement of the central measuring seat; S4. According to the displacement transfer formula, decouple the signals sent by the non-contact displacement sensor to obtain a measurement result including contour information; S5. Measure the three-dimensional contour of the probe end to obtain the shape error of the probe end, map the shape error onto the surface contour of the component to be detected, establish a surface contour model of the component to be detected, perform online contour error compensation on the measurement result in step S4, and finally obtain the final measurement result after error compensation.

[0023] The method of the present invention effectively controls and corrects the errors in the measurement process from multiple aspects through multi-stage compensation, enhancing the reliability and credibility of the measurement result; at the same time, it has the advantages of better adaptability to complex environments and better measurement capabilities for complex components. The present invention establishes a probe displacement signal-temperature and humidity model, and uses the real-time signals of the temperature and humidity sensors to calculate the signal fluctuation component, performing online error compensation on the non-contact displacement sensor, effectively reducing the influence of environmental temperature and humidity changes on the measurement result and significantly improving the measurement accuracy. By decoupling the signals sent by the non-contact displacement sensor, the actual displacement of the probe end can be obtained more accurately, further improving the accuracy of the measurement result. Considering the shape error of the probe end and mapping it onto the surface contour of the component to be detected, a surface contour model is established to achieve online contour error compensation for the measurement result, effectively reducing the influence of the probe end shape error on the measurement result and making the final measurement result more real and reliable; due to manufacturing processes and processing errors, there are extremely small concavities and convexities on the probe end / measuring ball of the present invention, and the measuring ball is not a perfect sphere. Step S5 of the present invention compensates for the shape error of the probe end, further improving the three-dimensional contour measurement accuracy of the component to be detected.

[0024] Preferably, in step S1, temperature sensors and humidity sensors are arranged to detect changes in the ambient temperature, and at the same time, the readings of the non-contact displacement sensors are recorded. Based on the recorded sample data, a probe displacement signal-temperature and humidity model is established by the least squares method. The compensation value S_compensation = K1T + K2H + K3, where K1, K2, and K3 are the model coefficients obtained by the least squares method, T is the temperature value detected by the temperature sensor in real time, and H is the humidity value detected by the humidity sensor in real time.

[0025] By arranging temperature sensors and humidity sensors to detect changes in the ambient temperature and humidity in real time and recording the readings of the non-contact displacement sensors, a large amount of sample data can be obtained. Using the least squares method to process these data, an accurate probe displacement signal-temperature and humidity model can be established. This model can accurately reflect the influence of changes in the ambient temperature and humidity on the displacement sensor signal, providing a reliable basis for subsequent error compensation. The compensation formula is simple and clear, facilitating real-time calculation and compensation. By obtaining the detection values (T, H) of the temperature sensor and humidity sensor in real time and substituting them into the compensation formula, the compensation value (S 补偿 ) can be quickly calculated, and based on this, an online error compensation is performed on the detection value of the non-contact displacement sensor, effectively reducing signal fluctuations caused by changes in the ambient temperature and humidity and improving the measurement accuracy. The least squares method is a mature and stable numerical method, and the model coefficients (K1, K2, K3) obtained by this method have good stability and convergence, ensuring that the performance of the model remains consistent under different measurement conditions and reducing model errors and uncertainties. The implementation of real-time compensation makes the measurement process more concise and efficient. There is no need to perform complex offline processing and correction on the data after measurement. The measurement personnel can directly obtain accurate measurement results after compensation, simplifying the measurement process and improving work efficiency.

[0026] Preferably, in step S3, the displacement transfer formula between the probe end and the central measurement seat is S 测量值 = Rx, where S 测量值 is the displacement in three-dimensional directions generated by the central measurement seat detected by the non-contact displacement sensor, R is the displacement transfer matrix, and x is the displacement in three-dimensional directions generated by the contact between the probe end and the component.

[0027] Preferably, when symmetric non-contact displacement sensors are arranged in the X or Y direction, the final displacement value S 测量值终 in three-dimensional directions generated by the central measurement seat detected by the non-contact displacement sensor is (S 测量值1 - S 测量值2 ) / 2, where S 测量值1 and S 测量值2 are the displacements in three-dimensional directions generated by the central measurement seat detected by two symmetrically arranged non-contact displacement sensors.

[0028] The symmetrically arranged non-contact displacement sensors can effectively eliminate the common-mode interference caused by environmental factors (such as temperature changes, electromagnetic interference, etc.). These interferences usually have similar effects on the two sensors. By taking the difference and dividing it by 2, the influence of the common-mode interference on the measurement results can be significantly reduced. By performing differential processing on the measurement values of the two sensors, the errors caused by individual differences of the sensors can be suppressed, making the measurement results more accurate, and enabling the present invention to be used for more complex and higher-precision three-dimensional contour detection.

[0029] The present invention provides a three-dimensional contour detection solution for component surfaces with high precision and strong adaptability, which is applicable to a variety of complex environments and measurement requirements, and has the advantages of significantly improving the performance and reliability of the detection system, so as to obtain high-precision and highly accurate measurement results. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 is a sectional view of the probe mechanism of the present invention.

[0031] Figure 2 is a schematic structural diagram of the probe mechanism of the present invention after removing the outer shell.

[0032] Figure 3 is a signal processing flow chart of the online error compensation method for the weak stiffness detection of the surface three-dimensional contour.

[0033] Figure 4 is a fitting flow chart of the non-contact displacement sensor and the temperature and humidity relationship model algorithm.

[0034] Figure 5 is a calibration and decoupling schematic diagram of the probe system based on the coupling of the non-contact displacement sensor and the elastic member.

[0035] Figure 6 is an online compensation schematic diagram of the surface contour of the probe ball of the probe system. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0036] The following further describes the present invention according to the drawings and specific embodiments.

[0037] Consisting of Figure 1 and Figure 2As shown in the figure, this embodiment discloses a high-precision three-dimensional contour weak stiffness detection system for the surface of a component, including a positioning mechanism (not shown in the figure) for positioning and fixing the component to be detected (not shown in the figure), a probe mechanism 100, and a motion mechanism (not shown in the figure) for driving the probe mechanism 100 to move. The part of the detection system in this embodiment except the probe mechanism 100 can adopt the structure of any existing three-dimensional contour detection system. The probe mechanism 100 in this embodiment includes a probe rod 1. The upper end of the probe rod 1 is fixed to the central measurement seat 2, and a probe ball 11 for contacting the component to be detected (not shown in the figure) is coaxially fixed at the lower end of the probe rod 1.

[0038] An outer shell linked with the motion mechanism is sleeved outside the central measurement seat 2. The outer shell includes a shell body 31 and a lower cover 32. The lower cover 32 is sleeved outside the probe rod 1, and the central measurement seat 2 is located in the inner cavity formed by the shell body 31 and the lower cover 32. The central measurement seat 2 is connected and supported in the inner cavity of the outer shell through an elastic member. The elastic member includes X-direction elastic members 51, Y-direction elastic members 52, and Z-direction elastic members 53 that are symmetrically arranged in pairs. The X-direction elastic members 51, Y-direction elastic members 52, and Z-direction elastic members 53 are arranged orthogonally to each other. The probe rod 1 is arranged along the Z direction and is coaxial with the Z-direction elastic member. The probe rod 1 is connected directly below the center of the central measurement seat 2. At least one non-contact displacement sensor 4 fixed to the outer shell is arranged in each of the three orthogonal directions of the central measurement seat 2. The shell body 31 is provided with a fitting hole for the outer end of the non-contact displacement sensor to pass through, and a part of the non-contact displacement sensor extends to the outside of the outer shell.

[0039] Among them, a temperature sensor and a humidity sensor (not shown in the figure) for detecting the air temperature and humidity between the central measurement seat 2 and the outer shell are arranged on the outer shell. The elastic member in this embodiment is a spring and is sleeved outside the non-contact displacement sensor 4. Part of the components of the central measurement seat 2, the outer shell, and the non-contact displacement sensor 4 are made of low-expansion alloy (invar). The non-contact displacement sensor 4 in this embodiment adopts a capacitive displacement sensor.

[0040] This embodiment discloses a measurement method using the above-mentioned high-precision three-dimensional contour weak stiffness detection system for the surface of a component, as shown in Figures 3 to 6 , including steps S1 - S5.

[0041] S1. Establish a probe displacement signal - humidity and temperature model. In step S1, the change in ambient temperature is detected by arranging a temperature sensor and a humidity sensor, and at the same time, the reading change of the non-contact displacement sensor is recorded. Through the recorded sample data, a probe displacement signal - temperature and humidity model is established by the least squares method, and the compensation value S 补偿 = K1T + K2H + K3, where K1, K2, and K3 are model coefficients obtained by the least squares method, T is the temperature value detected in real time by the temperature sensor, and H is the humidity value detected in real time by the humidity sensor.

[0042] S2. Based on the probe displacement signal-temperature and humidity model obtained in step S1 and the real-time collected signals from the temperature sensor and humidity sensor, calculate the signal fluctuation component of the non-contact displacement sensor caused by changes in ambient temperature and humidity, and perform online error compensation on the value detected by the non-contact displacement sensor.

[0043] S3. Perform a three-dimensional displacement calibration experiment on the component to be tested, obtain the displacement value S measured by all non-contact displacement sensors when the center measuring seat is displaced in the X, Y and Z directions, and establish the displacement transfer formula between the measuring ball displacement and the center measuring seat. In step S3, the displacement transfer formula between the measuring ball displacement and the center measuring seat is S 测量值 =Rx,S 测量值 The displacement in the three-dimensional direction of the center measuring seat detected by the non-contact displacement sensor is R, the displacement transfer matrix, and x, the displacement in the three-dimensional direction generated by the contact between the measuring ball and the component. When a symmetrical non-contact displacement sensor is set in the X or Y direction, the final displacement value of the three-dimensional direction generated by the center measuring seat detected by the non-contact displacement sensor is =( - ) / 2, and The displacement transfer matrix R is measured using the high-precision displacement stage included in the calibration test and detection system.

[0044] S4. According to the above displacement transfer formula, the signal emitted by the non-contact displacement sensor is decoupled to obtain a measurement result including contour information.

[0045] S5. Measure the three-dimensional profile of the stylus ball to obtain its topographic error. This topographic error is mapped onto the surface profile of the component to be measured, and a surface profile model of the component to be measured is established. The measurement results from step S4 are then subjected to online profile error compensation to obtain the final measurement result after error compensation. In step S5, by measuring a high-precision standard sphere (hereinafter referred to as the "standard sphere"), the surface profile detection error of the standard sphere can be reflected on the surface profile of the stylus ball. This surface profile detection error of the standard sphere is mapped onto the surface profile of the stylus ball using existing algorithms such as a mapping algorithm, thereby facilitating the establishment of the stylus ball surface profile model. To improve surface modeling accuracy, the standard sphere should be larger than the stylus ball. The mapping formula is α→H(α), where α is the stylus ball's movement direction and corresponds to the angle at which the stylus ball contacts the component to be measured, and H(α) is the corresponding topographic value of the stylus ball.

Claims

1. A high-precision three-dimensional contour weak stiffness detection system for the surface of a component, comprising a positioning mechanism for positioning and fixing the component to be detected, a probe mechanism, and a motion mechanism for driving the probe mechanism to move. The probe mechanism includes a probe rod for contacting the component to be detected, and is characterized in that: One end of the measuring rod is fixed to the central measuring seat. An outer shell linked to the motion mechanism is sleeved outside the central measuring seat. The central measuring seat is connected and supported inside the outer shell through an elastic member. The elastic member includes X-direction elastic members, Y-direction elastic members, and Z-direction elastic members that are symmetrically arranged in pairs. The X-direction elastic members, Y-direction elastic members, and Z-direction elastic members are arranged orthogonally to each other in pairs. At least one non-contact displacement sensor fixed to the outer shell is provided in each of the three orthogonal directions of the central measuring seat. A temperature sensor and a humidity sensor for detecting the air temperature and humidity between the central measuring seat and the outer shell are provided on the outer shell.

2. The high-precision three-dimensional contour weak stiffness detection system for the surface of a component according to claim 1, characterized in that: The elastic member is sleeved outside the non-contact displacement sensor.

3. The high-precision three-dimensional contour weak stiffness detection system for the surface of a component according to claim 1 or 2, characterized in that: Some components of the central measuring seat, the outer shell, and the non-contact displacement sensor are made of materials with low thermal expansion coefficients.

4. The high-precision three-dimensional contour weak stiffness detection system for the surface of the component according to claim 1, wherein: The outer shell is provided with a mating hole for a part of the non-contact displacement sensor to pass through, and a part of the non-contact displacement sensor extends to the outside of the outer shell.

5. The high-precision three-dimensional contour weak stiffness detection system for the surface of a component according to claim 1, characterized in that: The measuring rod is arranged along the Z direction and is coaxial with the Z-direction elastic member. The measuring rod is connected below the central measuring seat. The outer shell includes a housing and a lower cover. The lower cover is sleeved outside the measuring rod.

6. The high-precision three-dimensional contour weak stiffness detection system for the surface of a component according to claim 1 or 5, characterized in that: A measuring ball is provided at the end of the measuring rod away from the central measuring seat.

7. A measurement method of a high-precision three-dimensional contour weak stiffness detection system for the surface of the component described in any one of claims 1 to 6, characterized in that It includes the following steps: S1. Establish a probe displacement signal - humidity and temperature model; S2. According to the probe displacement signal - humidity and temperature model obtained in step S1 and the real-time acquisition signals of the temperature sensor and the humidity sensor, calculate the signal fluctuation component generated by the non-contact displacement sensor due to environmental temperature and humidity changes, and perform online error compensation on the value detected by the non-contact displacement sensor; S3. Conduct a three-dimensional displacement calibration experiment on the component to be detected, and obtain the displacement values S generated by all non-contact displacement sensors under the displacement of the central measuring seat in the X, Y, and Z directions. 测量值 , and establish a displacement transfer formula between the displacement of the end of the measuring rod and the displacement of the central measuring seat; S4. According to the displacement transfer formula, decouple the signal sent by the non-contact displacement sensor to obtain a measurement result including profile information; S5. Measure the three-dimensional profile of the end of the measuring rod to obtain the shape error of the end of the measuring rod. Map the shape error onto the surface profile of the component to be measured, establish a surface profile model of the component to be measured, and perform online profile error compensation on the measurement result in step S4 to finally obtain the final measurement result after error compensation.

8. The measuring method according to claim 7, characterized in that: In step S1, the change in ambient temperature is detected by arranging temperature sensors and humidity sensors, and at the same time, the change in the reading of the non-contact displacement sensor is recorded. Based on the recorded sample data, a probe displacement signal-temperature and humidity model is established by the least squares method, and the compensation value S 补偿 = K1T + K2H + K3, where K1, K2, and K3 are model coefficients obtained by the least squares method, T is the temperature value obtained by real-time detection of the temperature sensor, and H is the humidity value obtained by real-time detection of the humidity sensor.

9. The measuring method according to claim 7, characterized in that: In step S3, the displacement transfer formula between the displacement of the probe end and the central measuring seat is S 测量值 =Rx, where S 测量值 is the displacement in three-dimensional directions generated by the central measuring seat detected by the non-contact displacement sensor, R is the displacement transfer matrix, and x is the displacement in three-dimensional directions generated by the contact between the probe end and the component.

10. The measurement method according to claim 9, wherein: When symmetric non-contact displacement sensors are set in the X or Y direction, the final displacement value in the three-dimensional direction generated by the central measurement seat detected by the non-contact displacement sensors =( - ) / 2, and are the displacements in the three-dimensional direction generated by the central measurement seat detected by two symmetrically set non-contact displacement sensors.

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