Temperature compensation device, measurement system, temperature compensation method and computer program product

Abstract

The invention provides a temperature compensation apparatus, a measurement system, a temperature compensation method, and a computer program product. The temperature compensation device (100) includes: a measured temperature acquisition unit (141) for acquiring a temperature of the three-dimensional measurement device (10) during measurement; the measurement result acquisition part (142) is used for acquiring a measurement result of the to-be-measured object output by the three-dimensional measurement equipment (10); a correction value calculation unit (143) for calculating a correction value of the measurement result using a temperature compensation model formula including a polynomial consisting of values obtained by multiplying each of the plurality of temperatures by a coefficient corresponding to each of the plurality of temperature sensors (20); and a correction unit (144) for calculating a corrected measurement value, which is a corrected measurement result obtained by adding the correction value and the measurement result or multiplying the correction value and the measurement result.

Description

Technical Field

[0001] The present disclosure relates to a temperature compensation device, a measurement system, a temperature compensation method and a storage medium. Background Art

[0002] A measuring device for measuring the three-dimensional geometry of a measuring object in a contact or non-contact manner is known (for example, refer to Patent Document 1 (Japanese Patent Laid-Open No. 2004-341608) and Patent Document 2 (Japanese Patent Table No. 2019-507885)). This measuring device can accurately measure the three-dimensional geometry of the measuring object when the ambient temperature is stable. In other words, in order to measure with high accuracy, the measuring device requires a stable ambient temperature. Summary of the invention

[0003] Problem that the invention aims to solve

[0004] In the case where such a measuring device is installed in an environment with temperature fluctuations such as a factory, thermal expansion or the like may occur in the object to be measured and various parts of the measuring device, thereby causing errors in the measurement results. Conventionally, methods such as calculating the amount of thermal expansion of the object to be measured based on the temperature of the object to be measured and correcting the measurement result of the measuring device, or correcting simple expansion and contraction of a scale or the like are known. However, uneven temperature or the like in the object to be measured may occur, resulting in a situation where a high-precision measurement result cannot be obtained.

[0005] The present disclosure focuses on these problems, and an object thereof is to make it possible to easily and accurately correct errors in measurement results of a three-dimensional measuring device caused by ambient temperature changes.

[0006] Solutions for solving problems

[0007] According to a first aspect of the present disclosure, a temperature compensation device is provided for performing temperature compensation on a measurement result of an object to be measured output by a three-dimensional measuring device installed in a variable temperature environment, the temperature compensation device comprising: a measurement temperature acquisition unit for acquiring the temperature of the three-dimensional measuring device during measurement from a plurality of temperature sensors arranged at a plurality of different positions of the three-dimensional measuring device, a temperature sensor for measuring the ambient temperature of the three-dimensional measuring device, and a temperature sensor for measuring the temperature of the object to be measured; a measurement result acquisition unit for acquiring the measurement result of the object to be measured output by the three-dimensional measuring device; and a correction value calculation unit for using a temperature compensation including a polynomial. A model formula is used to calculate a correction value of the measurement result, the polynomial is composed of a value obtained by multiplying each of the multiple temperatures obtained from the multiple temperature sensors by a coefficient corresponding to each of the multiple temperature sensors; and a correction unit is used to calculate a corrected measurement value, the corrected measurement value is a corrected measurement result obtained by adding the correction value and the measurement result or multiplying the correction value and the measurement result, wherein the coefficient corresponding to each of the multiple temperature sensors is a value identified in a manner that minimizes an evaluation function based on a difference between an ideal measurement value obtained by measuring an object to be measured installed in a constant temperature environment at a predetermined temperature and the correction value.

[0008] The temperature compensation model formula used by the correction value calculation unit can be expressed as follows:

[0009]

[0010] The temperature acquired by the measured temperature acquisition unit from a total of P temperature sensors is x p The correction value calculated by the correction value calculation unit is y', and the coefficient corresponding to each of the plurality of temperature sensors is b p , and b0 is a constant term, and p is an integer from 1 to P.

[0011] The evaluation function can be expressed as L in the following formula:

[0012]

[0013] The ideal measurement value is Y, and the measurement result obtained by the measurement result acquisition unit is y n , and with the measurement result y n The corresponding correction value calculated by the correction value calculation unit is y n ', n is an integer from 1 to N.

[0014] The correction value calculation section may calculate the correction value by switching coefficients corresponding to each of the plurality of temperature sensors to coefficients identified according to the ambient temperature of the three-dimensional measuring device, according to the ambient temperature of the three-dimensional measuring device.

[0015] The correction value calculation section may calculate the correction value by switching a coefficient corresponding to each of the plurality of temperature sensors to a coefficient identified according to the elapsed time, according to the time that has elapsed since the three-dimensional measuring apparatus started measurement.

[0016] The correction value calculation section may calculate the correction value by switching coefficients corresponding to each of the plurality of temperature sensors to coefficients identified according to the measurement item to be measured by the three-dimensional measuring device, according to the measurement item to be measured by the three-dimensional measuring device.

[0017] The correction value calculation section may calculate the correction value by switching coefficients corresponding to each of the plurality of temperature sensors to coefficients identified according to the position of the object to be measured.

[0018] At least one of the temperature sensors may be disposed at a position in the portion of the three-dimensional measuring device having a temperature variation trend different from a temperature variation trend of the object to be measured caused by a change in ambient temperature.

[0019] Two or more temperature sensors may be disposed at locations in the portion of the three-dimensional measuring device, each having a different temperature change trend with respect to an ambient temperature change.

[0020] The second aspect of the present disclosure provides a measurement system, which includes: a three-dimensional measuring device for measuring the three-dimensional geometric shape of an object to be measured; a plurality of temperature sensors arranged at a plurality of different positions of the three-dimensional measuring device; and a temperature compensation device according to the first aspect of the present disclosure, for performing temperature compensation on the measurement results of the three-dimensional measuring device based on a plurality of temperatures acquired by the plurality of temperature sensors.

[0021] A third aspect of the present disclosure provides a temperature compensation method for temperature compensating a measurement result of an object to be measured output by a three-dimensional measuring device installed in a variable temperature environment, the temperature compensation method comprising the following steps: obtaining the temperature of the three-dimensional measuring device during measurement from a plurality of temperature sensors arranged at a plurality of different positions of the three-dimensional measuring device and a temperature sensor for measuring the ambient temperature of the three-dimensional measuring device; obtaining the measurement result; calculating a correction value of the measurement result using a model formula for temperature compensation including a polynomial, the polynomial being composed of values ​​obtained by multiplying each of the plurality of temperatures obtained from the plurality of temperature sensors by coefficients corresponding to each of the plurality of temperature sensors; and calculating a corrected measurement value, the corrected measurement value being a corrected measurement result obtained by adding the correction value to the measurement result or multiplying the correction value by the measurement result, wherein the coefficient corresponding to each of the plurality of temperature sensors is a value identified in a manner that minimizes an evaluation function based on the difference between an ideal measurement value obtained by measuring the object to be measured installed in a constant temperature environment at a predetermined temperature and the correction value.

[0022] A fourth aspect of the present disclosure provides a storage medium storing a program, which, when executed by a computer, causes the computer to function as the temperature compensation device according to the first aspect of the present disclosure.

[0023] Effects of the Invention

[0024] According to the present disclosure, it is possible to easily and accurately correct a measurement error caused by a temperature of a measurement result of a three-dimensional measurement device caused by a change in ambient temperature. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 A configuration example of the measurement system S according to the present embodiment is shown.

[0026] Figure 2 A configuration example of the temperature compensation device 100 according to the present embodiment is shown.

[0027] Figure 3 An example of the operation flow of the temperature compensating device 100 according to the present embodiment is shown.

[0028] [Explanation of Reference Numerals]

[0029] 10 3D measuring equipment

[0030] 20 Temperature Sensor

[0031] 100 Temperature compensation equipment

[0032] 110 Communications Department

[0033] 120 Storage Department

[0034] 130 Display unit

[0035] 140 Control Department

[0036] 141 Measurement temperature acquisition unit

[0037] 142 Measurement result acquisition unit

[0038] 143 correction value calculation unit

[0039] 144 Correction Department DETAILED DESCRIPTION

[0040] <Configuration example of measurement system S>

[0041] Figure 1 The configuration example of the measuring system S according to the present embodiment is shown. The measuring system S performs temperature compensation for the measurement error of the temperature of the measurement result of the measuring device caused by the change of the ambient temperature. The measuring system S includes a three-dimensional measuring device 10, a plurality of temperature sensors 20, and a temperature compensation device 100.

[0042] The three-dimensional measuring device 10 measures the three-dimensional geometric shape of the object D to be measured. The three-dimensional measuring device 10 includes: a coordinate measuring unit for measuring the three-dimensional coordinates of the object D to be measured; and a controller (e.g., a computer) for calculating the shape, spatial position relationship, and distances between multiple positions of the object D to be measured, etc., based on the multiple three-dimensional coordinates identified. The three-dimensional measuring device 10 measures the three-dimensional geometric shape of the object D to be measured by measuring the three-dimensional coordinates of multiple positions of the object D to be measured. Because such a three-dimensional measuring device 10 is known and described in Patent Document 1, etc., a detailed description of the three-dimensional measuring device 10 will be omitted here.

[0043] A plurality of temperature sensors 20 are provided at a plurality of different positions of the three-dimensional measuring device 10. Among the plurality of temperature sensors 20, at least one temperature sensor 20 measures the ambient temperature of the three-dimensional measuring device 10. In addition, at least one temperature sensor 20 measures the temperature of the object to be measured D. The plurality of temperature sensors 20 are, for example, a resistance temperature detector using platinum or a similar material, a thermocouple, a thermistor, or the like.

[0044] The temperature compensation device 100 performs temperature compensation on the measurement result of the object D to be measured output by the three-dimensional measuring device 10 installed in a variable temperature environment, based on the temperature measured by the plurality of temperature sensors 20. The three-dimensional measuring device 10 can accurately measure the three-dimensional geometry of the object D to be measured in a temperature-stable environment such as a measuring room or a laboratory. However, when the three-dimensional measuring device 10 is installed in a temperature-fluctuating environment such as in a factory, thermal expansion may occur in the components of the three-dimensional measuring device 10 due to changes in ambient temperature, heat from the device itself, or other factors, thereby potentially causing errors in the measurement results. It is conceivable to perform a simple correction for thermal expansion, but it is sometimes difficult to accurately correct the errors in the measurement results.

[0045] Conventionally, the temperature T of the object D to be measured is measured by the three-dimensional measuring device 10. D Used for the temperature expansion a of the object D to be measured w ×(T D -T E )×L S To correct the measurement result of the three-dimensional measuring device 10, the temperature expansion amount a w ×(T D -T E )×L S From the temperature T D and the predetermined ambient temperature T E (For example, T E =20℃) D -T E ) is calculated. Here, a w is the coefficient of thermal expansion.

[0046] For example, when the three-dimensional measuring device 10 measures the distance between the center positions of two holes set in the object to be measured D, and the measurement result is L S When the controller of the three-dimensional measuring device 10 corrects the measurement result L of the three-dimensional measuring device 10 using the following formula S , to calculate the corrected measurement value L S '.

[0047] [Formula 1]

[0048] L S ′ =L S ·{1-a W ·(T D -T E )}

[0049] However, if the change in ambient temperature occurs significantly or rapidly, temperature non-uniformity may occur in the object D to be measured, which causes the correction amount of the measurement result to be different from the actual expansion amount of the object D to be measured, thereby resulting in reduced measurement accuracy.

[0050] In addition, the change in the expansion amount of the object D to be measured may sometimes follow the temperature change of the object D to be measured with a time delay. For example, when the temperature of the object D to be measured decreases from the high temperature side to the first temperature in response to the change in the ambient temperature, there is a case where the object D to be measured is in an expanded state.

[0051] In addition, for example, when the temperature of the object D to be measured rises from the low temperature side to the first temperature in response to a change in the ambient temperature, there is a case where the object D to be measured is in a contracted state. Therefore, in a variable temperature environment, even if the temperature of the object D to be measured is at the first temperature, the expansion amount of the object D to be measured may be different. Therefore, the measurement result cannot always be accurately corrected by a conventional correction formula such as Formula 1.

[0052] In addition, since various measurement items are measured for the object D to be measured of the three-dimensional measuring device 10, the use of a single correction formula may result in a change between an item whose error may be reduced and an item whose error may not be reduced. In addition, when the object D to be measured is not formed of a uniform material, it may be difficult to accurately identify the thermal expansion coefficient of the object D to be measured, etc. When the object D to be measured has a complex shape or a large volume, the temperature may be non-uniform, making it difficult to accurately identify the temperature. Therefore, the temperature compensation device 100 makes it possible to easily and accurately correct the error of the measurement result of the three-dimensional measuring device 10 caused by the change in the ambient temperature. Next, such a temperature compensation device 100 will be described.

[0053] <Configuration Example of Temperature Compensation Device 100>

[0054] Figure 2 A configuration example of a temperature compensation device 100 according to the present embodiment is shown. The temperature compensation device 100 is, for example, a computer such as a PC or a server, etc. The temperature compensation device 100 includes a communication section 110 , a storage section 120 , a display section 130 , and a control section 140 .

[0055] The communication section 110 communicates with the three-dimensional measuring device 10. The communication section 110 may be directly connected to the three-dimensional measuring device 10, or alternatively, may communicate via a communication network, etc. The communication section 110 may include an interface for connecting to a communication network such as a LAN, an Internet line, or a mobile phone network, etc. The communication section 110 can access an external server, a PC, a database, etc.

[0056] By communicating with the three-dimensional measuring device 10, the communication unit 110 acquires information related to the measurement results of the three-dimensional measuring device 10 and information related to the temperatures measured by the plurality of temperature sensors 20. The measurement results are, for example, the position of a predetermined part, the position of a circle center, the position of a sphere center, the diameter of a hole, the distance between end faces, the distance between two predetermined parts, the relative position between two predetermined parts, the shape of a measured component, the posture of a component, etc., which are calculated by the three-dimensional measuring device 10 based on a plurality of three-dimensional coordinates.

[0057] It should be noted that the communication unit 110 can directly communicate with the plurality of temperature sensors 20 to obtain information related to the temperatures measured by the temperature sensors 20. In addition, in the case where a controller or the like for controlling the measurement operation of the three-dimensional measuring device 10 is provided, the communication unit 110 can communicate with the controller to obtain information related to the measurement results of the three-dimensional measuring device 10 and information related to the temperatures measured by the temperature sensors 20, etc.

[0058] The storage unit 120 includes a storage medium such as a read-only memory (ROM) or a random access memory (RAM). The storage unit 120 may include a large-capacity storage device such as a hard disk drive (HDD) and / or a solid-state drive (SSD). As an example, when a computer is used as the temperature compensation device 100, the storage unit 120 may store an operating system (OS) and information such as programs that make the computer function. The storage unit 120 may store various types of information including programs for operating the three-dimensional measurement device 10 and databases referenced when executing various programs.

[0059] In addition, the storage unit 120 may store intermediate data, calculation results, threshold values, reference values, parameters, and the like generated (or used) during the operation of the temperature compensation device 100. For example, the storage unit 120 may store information related to the measurement results of the three-dimensional measurement device 10 and information related to the temperatures measured by the plurality of temperature sensors 20, and the like. The storage unit 120 may be a database or the like provided outside the temperature compensation device 100. The storage unit 120 may supply the stored data to the request source in response to a request from each component in the temperature compensation device 100.

[0060] The display section 130 displays information related to the measurement results of the three-dimensional measuring device 10 and information related to the correction results of the temperature compensation device 100, etc. The display section 130 can also be used as a display for displaying the operation state of the three-dimensional measuring device 10, the operation state and communication state of the temperature compensation device 100, the execution state of the OS and the program, etc. The display section 130 may have a touch panel function and operate as an input section 131. Operations and instructions from the user of the temperature compensation device 100 are input to the input section 131. The input section 131 may be an input device separate from the display section 130, such as a keyboard, a mouse, or an audio input device.

[0061] The control section 140 controls the components of the temperature compensation device 100. The control section 140 is, for example, a CPU (central processing unit). The control section 140 includes a measured temperature acquisition section 141, a measurement result acquisition section 142, a correction value calculation section 143, a correction section 144, and an output section 145. In other words, by executing the program stored in the storage section 120, the CPU functions as the control section 140 including the measured temperature acquisition section 141, the measurement result acquisition section 142, the correction value calculation section 143, the correction section 144, and the output section 145.

[0062] The measured temperature acquisition unit 141 acquires the temperature of the three-dimensional measuring device 10 during the measurement from the plurality of temperature sensors 20 via the communication unit 110. The measured temperature acquisition unit 141 acquires, for example, the temperature of each component of the three-dimensional measuring device 10, the ambient temperature, and the temperature of the object to be measured D during the measurement of the three-dimensional measuring device 10. The measured temperature acquisition unit 141 can acquire the temperatures measured by the plurality of temperature sensors 20 at predetermined time intervals for each predetermined time period while repeatedly measuring the same measurement item of the object to be measured D.

[0063] The measurement result acquisition unit 142 acquires the measurement result of the object D to be measured measured by the three-dimensional measurement device 10 via the communication unit 110. The measurement result is, for example, the position of a predetermined part, the position of the center of a circle, the position of the center of a sphere, the diameter of a hole, the distance between end faces, the distance between two predetermined parts, the relative position between two predetermined parts, the shape of the measured component or the posture of the component, etc. The measurement result may include the area or volume of the predetermined part, etc.

[0064] Correction value calculation section 143 calculates a correction value of a measurement result using a model formula for temperature compensation including a polynomial consisting of values ​​obtained by multiplying each of a plurality of temperatures acquired from a plurality of temperature sensors 20 by a coefficient corresponding to each of the plurality of temperature sensors 20 .

[0065] For example, the correction value calculation unit 143 uses the model formula of temperature compensation shown in the following equation. Here, when the three-dimensional measuring device 10 measures the object D to be measured and outputs the measurement result y, the temperature acquired from a total of P temperature sensors 20 by the measurement temperature acquisition unit 141 is defined as x p (p is an integer from 1 to P), the correction value calculated by the correction value calculation unit 143 is defined as y', and the coefficient corresponding to each of the plurality of temperature sensors 20 is defined as b p , and the constant term is defined as b0.

[0066] [Formula 2]

[0067]

[0068] The coefficient b corresponding to each of the plurality of temperature sensors 20 is included. p The coefficient b of the model formula with constant term b0 p (p is an integer from 0 to P) can be identified by learning. For example, the coefficient b of the model formula p is to make the temperature based on the measurement of the E The value identified in a manner that minimizes the evaluation function L of the difference between the ideal measurement value and the correction value obtained for the object to be measured D in a constant temperature environment of (=20° C.).

[0069] Note that the ideal measurement value is a value obtained by measuring the object D to be measured using a three-dimensional measuring device having higher measurement accuracy than the three-dimensional measuring device 10 according to the present embodiment.

[0070] [Formula 3]

[0071]

[0072] Here, assuming that the ideal measurement value is Y, the measurement result obtained by the measurement result acquisition unit 142 is y n (n is an integer from 1 to N), and the correction value calculation unit 143 calculates the value corresponding to the measurement result y n The corresponding correction value is y n '. The coefficient b of the model formula p is calculated in advance and stored in the storage unit 120. By using such a coefficient b p For example, when the measurement result of the three-dimensional measuring device 10 becomes a value closer to the ideal measurement value, the correction value calculation section 143 calculates the correction value y′ that becomes a value closer to zero.

[0073] The correction unit 144 calculates a corrected measurement value, which is a corrected measurement result obtained by adding the correction value y' and the measurement result or multiplying the correction value y' and the measurement result. For example, the correction unit 144 takes the corrected measurement value as y+y'. The output unit 145 outputs the corrected measurement value calculated by the correction unit 144. For example, the output unit 145 causes the display unit 130 to display the corrected measurement value. The output unit 145 can cause the display unit 130 to display the corrected measurement value together with the measurement result y. The correction unit 144 can store the corrected measurement value in the storage unit 120, or can output the corrected measurement value to an external server or an external database, etc.

[0074] As described above, the temperature compensation device 100 according to the present embodiment reflects the relationship between (i) various temperatures (such as the temperature of each component of the three-dimensional measuring device 10, the ambient temperature, and the temperature of the object to be measured D) and (ii) the value of the measurement error occurring in the object to be measured D in the coefficient b of the model formula. p As a result, even if temperature unevenness occurs in the object to be measured D, the temperature compensation device 100 can calculate a correction value reflecting the distribution of the temperature of each component of the three-dimensional measuring device 10 and the ambient temperature corresponding to the temperature unevenness. Therefore, the temperature compensation device 100 can accurately correct the measurement error caused by the temperature of the measurement result of the three-dimensional measuring device 10.

[0075] Furthermore, the temperatures output by the plurality of temperature sensors 20 change in response to changes in the ambient temperature, but the temperature of at least one of the various components of the three-dimensional measuring device 10 may not follow the same trend as the temperature change of the object to be measured D. For example, the temperature of a portion having a larger heat capacity than the object to be measured D may change more slowly than the temperature of the object to be measured D. In addition, the temperature of a portion having a smaller heat capacity than the object to be measured D may change faster than the temperature of the object to be measured D.

[0076] In this case, even if the temperature of the object D to be measured is at the same first temperature, the temperature of a predetermined certain component of the three-dimensional measuring device 10 changed from the high temperature side to the first temperature may be different from the temperature of the certain component of the three-dimensional measuring device 10 changed from the low temperature side to the first temperature. The coefficient b of the model formula is learned by reflecting the temperature of each component of the three-dimensional measuring device 10 having a temperature change trend different from the temperature change trend of the object D to be measured. p .

[0077] Therefore, even if the temperature of the object D to be measured is at the same first temperature, the temperature compensating device 100 can calculate a more accurate correction value corresponding to the error corresponding to the actual expansion amount of the object D to be measured. By doing so, the temperature compensating device 100 can correct the measurement error caused by the temperature of the three-dimensional measuring device 10, which cannot be corrected by the conventional correction formula.

[0078] As described above, at least one temperature sensor 20 is disposed at a position in the part of the three-dimensional measuring device 10 having a temperature change trend different from the temperature change trend of the object D to be measured caused by the change in ambient temperature. Preferably, two or more temperature sensors 20 are disposed at a plurality of positions in the part of the three-dimensional measuring device 10 each having a different temperature change trend with respect to the change in ambient temperature. By doing so, the temperature detected by the plurality of temperature sensors 20 will differ between a case where the ambient temperature changes significantly and a case where the ambient temperature changes slightly. Therefore, even if the degree of change in the ambient temperature changes, the temperature compensation device 100 can accurately correct the measurement error caused by the temperature of the measurement result of the three-dimensional measuring device 10.

[0079] In addition, the temperature compensation device 100 can calculate a correction value for directly correcting the measurement result of the three-dimensional measuring device 10 without using values ​​such as the expansion amount and expansion rate of the object to be measured D. Therefore, even for various measurement items of the three-dimensional measuring device 10, by using the coefficients identified based on the evaluation function, the temperature compensation device 100 can easily correct the measurement error caused by the temperature of the three-dimensional measuring device 10 without identifying the correction formula corresponding to each measurement item.

[0080] <Other Configurations of Temperature Compensation Device 100>

[0081] An example has been described in which the temperature compensation device 100 according to the present embodiment uses the coefficients of the model formula identified based on the evaluation function to perform temperature compensation, but the present disclosure is not limited thereto. It is also assumed that the ambient temperature of the three-dimensional measuring device 10 fluctuates significantly depending on the installation location, season, climate, etc. Therefore, the temperature compensation device 100 can divide the ambient temperature of the three-dimensional measuring device 10 into a plurality of temperature zones, and pre-identify the coefficients of the model formula for each divided temperature zone. In addition, the temperature compensation device 100 can pre-identify the coefficients of the model formula for each ambient temperature of the three-dimensional measuring device 10.

[0082] For example, the storage section 120 stores a coefficient bp1 identified when the ambient temperature is equal to or greater than 0°C but less than 10°C, a coefficient bp2 identified when the temperature is equal to or greater than 10°C but less than 20°C, a coefficient bp3 identified when the ambient temperature is equal to or greater than 20°C but less than 30°C, and a coefficient bp4 identified when the ambient temperature is not less than 30°C and less than 40°C. Then, the correction value calculation section 143 calculates the correction value by switching the coefficient of the model formula to a coefficient corresponding to the ambient temperature of the three-dimensional measuring device 10 among the pre-identified plurality of coefficients (e.g., bp1, bp2, bp3, and bp4). By doing so, even if the ambient temperature fluctuates significantly, the temperature compensation device 100 can accurately correct the measurement error caused by the temperature of the measurement result of the three-dimensional measuring device 10 by using the coefficient corresponding to the ambient temperature.

[0083] An example in which the temperature compensation device 100 switches the coefficients of the model formula according to the ambient temperature has been described, but the present disclosure is not limited thereto. The temperature compensation device 100 may switch the coefficients of the model formula according to the measurement time of the three-dimensional measuring device 10. The temperature change trends of the components of the three-dimensional measuring device 10 may be different according to states such as immediately after power is turned on, after a predetermined time has passed since power is turned on, after measurement is started after the installation position of the three-dimensional measuring device 10 has been moved, and the like.

[0084] Therefore, the temperature compensation device 100 can divide the measurement time of the three-dimensional measuring device 10 into a plurality of time zones from the start of the measurement, and pre-identify the coefficients of the model formula for each divided time zone. Then, the correction value calculation unit 143 calculates the correction value by switching the coefficients corresponding to each of the plurality of temperature sensors 20 to the coefficients identified according to the elapsed time according to the time period that has elapsed since the start of the measurement of the three-dimensional measuring device 10. By doing so, even if the temperature change trend fluctuates according to the time that has elapsed since the start of the measurement, the temperature compensation device 100 can accurately correct the measurement error caused by the temperature of the measurement result of the three-dimensional measuring device 10 by using the coefficient corresponding to the time that has elapsed since the start of the measurement.

[0085] In addition, the temperature compensation device 100 can switch the coefficients of the model formula according to the measurement items of the three-dimensional measuring device 10. Some measurement items of the three-dimensional measuring device 10 are easily affected by fluctuations in ambient temperature, some are not easily affected by fluctuations in ambient temperature, and some are affected by fluctuations in ambient temperature in a more complex manner.

[0086] Therefore, the temperature compensation device 100 can identify the coefficients of the model formula in advance for each measurement item of the three-dimensional measuring device 10. Then, the correction value calculation section 143 calculates the correction value by switching the coefficients corresponding to each of the plurality of temperature sensors 20 to the coefficients identified according to the measurement items of the three-dimensional measuring device 10 according to the measurement items to be measured by the three-dimensional measuring device 10. By doing so, the temperature compensation device 100 can accurately correct the measurement error caused by the temperature of the measurement result of the three-dimensional measuring device 10 by using the coefficients corresponding to the measurement items.

[0087] In addition, the temperature compensation device 100 can switch the coefficients of the model formula according to the position or area of ​​the object to be measured D. Some of the objects to be measured D are susceptible to fluctuations in ambient temperature due to the position or area, etc., some are not susceptible to fluctuations in ambient temperature, and some are affected by fluctuations in ambient temperature in a more complex manner. When the size of the object to be measured D is large, the behavior of the object to be measured D in response to changes in ambient temperature generally differs according to the position.

[0088] Therefore, the temperature compensation device 100 can identify the coefficients of the model formula for each position or region of the object to be measured D. Then, the correction value calculation part 143 calculates the correction value by switching the coefficients corresponding to each of the plurality of temperature sensors 20 to the coefficients identified according to the position of the object to be measured D according to the position of the object to be measured D. Therefore, the temperature compensation device 100 can accurately correct the measurement error caused by the temperature of the measurement result of the three-dimensional measuring device 10 by using the coefficients corresponding to the position or region of the object to be measured D.

[0089] The example in which the temperature compensation device 100 according to the present embodiment uses Formula 2 as a model formula for temperature compensation has been described, but the present disclosure is not limited thereto. The model formula for temperature compensation may be other model formulas as long as the model formula is a polynomial reflecting the temperature acquired from the plurality of temperature sensors 20. For example, the model formula may include high-order terms such as quadratic functions, or may include nonlinear terms or terms using time as a parameter, etc.

[0090] The temperature compensation device 100 according to the present embodiment has been described as an example using Equation 3 as the evaluation function L, but the present disclosure is not limited thereto. The evaluation function L may be any function as long as the difference between the ideal measurement value and the correction value can be evaluated, and other evaluation functions used in machine learning, etc. may be used.

[0091] An example in which the temperature compensation device 100 according to the present embodiment performs temperature compensation on the measurement result of the three-dimensional measuring device 10 has been described, but the present disclosure is not limited thereto. The temperature compensation device 100 can be used as a controller for operating the three-dimensional measuring device 10, for example. In addition, the controller for operating the three-dimensional measuring device 10 can be used as the temperature compensation device 100 by executing a predetermined program. In this case, a configuration in which one computer can perform the measurement operation of the three-dimensional measuring device 10 and the temperature compensation of the measurement result can be used.

[0092] <Operation Flow of Temperature Compensation Device 100>

[0093] Figure 3 An example of the operation flow of the temperature compensation device 100 according to the present embodiment is shown. Figure 3 The operation flow shown can perform temperature compensation on the measurement result of the object D to be measured output by the three-dimensional measuring device 10 installed in a variable temperature environment.

[0094] First, the measured temperature acquisition unit 141 acquires the temperature of the three-dimensional measuring device 10 during measurement from the temperature sensors 20 provided at a plurality of different positions of the three-dimensional measuring device 10 and the temperature sensor 20 for measuring the ambient temperature of the three-dimensional measuring device 10 (S51). Next, the measurement result acquisition unit 142 acquires the measurement result of the three-dimensional measuring device 10 (S52).

[0095] Next, the correction value calculation section 143 calculates the correction value of the measurement result using a model formula for temperature compensation, the model formula including a polynomial consisting of values ​​obtained by multiplying each of the plurality of temperatures acquired from the plurality of temperature sensors 20 by a coefficient corresponding to each of the plurality of temperature sensors 20 (S53). Next, the correction section 144 calculates a corrected measurement value (S54), which is a corrected measurement result obtained by adding or multiplying the correction value and the measurement result of the three-dimensional measuring device 10. Next, the output section 145 outputs the calculated corrected measurement value (S55).

[0096] The present invention has been described based on exemplary embodiments. The technical scope of the present invention is not limited to the scope described in the above embodiments, and various changes and modifications can be made within the scope of the present invention. For example, all or part of the device can be configured with any unit that is functionally or physically dispersed or integrated. In addition, new exemplary embodiments generated by any combination of embodiments are also included in the exemplary embodiments. In addition, the effects of the new exemplary embodiments generated by the combination also have the effects of the original exemplary embodiments.

Claims

1. A temperature compensation device for performing temperature compensation on a measurement result of an object to be measured output by a three-dimensional measurement device installed in a variable temperature environment, the temperature compensation device comprising: a measured temperature acquisition unit, configured to acquire the temperature of the three-dimensional measuring device during measurement from a plurality of temperature sensors disposed at a plurality of different positions of the three-dimensional measuring device, a temperature sensor for measuring the ambient temperature of the three-dimensional measuring device, and a temperature sensor for measuring the temperature of the object to be measured; A measurement result acquisition unit, used for acquiring the measurement result of the object to be measured output by the three-dimensional measurement device; a correction value calculation section for calculating a correction value of the measurement result using a model formula for temperature compensation including a polynomial composed of values ​​obtained by multiplying each of a plurality of temperatures acquired from the plurality of temperature sensors by a coefficient corresponding to each of the plurality of temperature sensors; as well as a correction unit, configured to calculate a corrected measurement value, wherein the corrected measurement value is a corrected measurement result obtained by adding the correction value to the measurement result or multiplying the correction value and the measurement result, The coefficients corresponding to the respective temperature sensors are values ​​identified in such a manner as to minimize an evaluation function based on a difference between an ideal measurement value obtained by measuring an object to be measured installed in a constant temperature environment at a predetermined temperature and the correction value.

2. The temperature compensation device according to claim 1, wherein: The temperature compensation model formula used by the correction value calculation unit is expressed by the following formula: The temperature acquired by the measured temperature acquisition unit from a total of P temperature sensors is x p The correction value calculated by the correction value calculation unit is y', and the coefficient corresponding to each of the plurality of temperature sensors is b p , and b0 is a constant term, and p is an integer from 1 to P.

3. The temperature compensation device according to claim 2, wherein: The evaluation function is represented as L in the following formula: The ideal measurement value is Y, and the measurement result obtained by the measurement result acquisition unit is y n , and with the measurement result y n The corresponding correction value calculated by the correction value calculation unit is y n ', n is an integer from 1 to N.

4. The temperature compensation device according to claim 1, wherein: The correction value calculation section calculates the correction value by switching coefficients corresponding to each of the plurality of temperature sensors to coefficients identified according to the ambient temperature of the three-dimensional measuring device, according to the ambient temperature of the three-dimensional measuring device.

5. The temperature compensation device according to claim 1, wherein: The correction value calculation section calculates the correction value by switching a coefficient corresponding to each of the plurality of temperature sensors to a coefficient identified according to the elapsed time, according to the time that has elapsed since the three-dimensional measuring apparatus started measurement.

6. The temperature compensation device according to claim 1, wherein: The correction value calculation section calculates the correction value by switching coefficients corresponding to each of the plurality of temperature sensors to coefficients identified according to the measurement item to be measured by the three-dimensional measuring device, according to the measurement item to be measured by the three-dimensional measuring device.

7. The temperature compensation device according to claim 1, wherein: The correction value calculation section calculates the correction value by switching coefficients corresponding to each of the plurality of temperature sensors to coefficients identified according to the position of the object to be measured.

8. The temperature compensation device according to claim 1, wherein: At least one of the temperature sensors is disposed at a position in the portion of the three-dimensional measuring device having a temperature change trend different from a temperature change trend of the object to be measured caused by a change in ambient temperature.

9. The temperature compensation device according to claim 1, wherein: The two or more temperature sensors are disposed at positions in the three-dimensional measuring device, each having a different temperature change trend with respect to a change in ambient temperature.

10. A measurement system comprising: 3D measuring equipment, used to measure the 3D geometry of the object to be measured; a plurality of temperature sensors disposed at a plurality of different positions of the three-dimensional measuring device; as well as The temperature compensation device according to any one of claims 1 to 9, configured to perform temperature compensation on the measurement result of the three-dimensional measurement device based on the multiple temperatures acquired by the multiple temperature sensors.

11. A temperature compensation method for performing temperature compensation on a measurement result of an object to be measured output by a three-dimensional measuring device installed in a variable temperature environment, the temperature compensation method comprising the following steps: acquiring the temperature of the three-dimensional measuring device during measurement from a plurality of temperature sensors disposed at a plurality of different positions of the three-dimensional measuring device and a temperature sensor for measuring an ambient temperature of the three-dimensional measuring device; obtaining the measurement result; calculating a correction value of the measurement result using a model formula for temperature compensation including a polynomial composed of values ​​obtained by multiplying each of a plurality of temperatures acquired from the plurality of temperature sensors by a coefficient corresponding to each of the plurality of temperature sensors; as well as calculating a corrected measurement value, wherein the corrected measurement value is a corrected measurement result obtained by adding the correction value to the measurement result or multiplying the correction value to the measurement result, The coefficients corresponding to the respective temperature sensors are values ​​identified in such a manner as to minimize an evaluation function based on a difference between an ideal measurement value obtained by measuring an object to be measured installed in a constant temperature environment at a predetermined temperature and the correction value. 12 . A computer program product comprising a program for causing a computer to execute the temperature compensation method according to claim 11 .

Images