Measurement apparatus, measurement method, and measurement control program

Abstract

To provide a measuring device, a measuring method, and a measurement control program capable of securing measurement accuracy even in a measurement environment where a temperature change occurs.SOLUTION: On the basis of temperatures at a plurality of points obtained on the basis of outputs from temperature sensors (80, 82, 84) installed at the plurality of points of the measuring device (1), a relative evaluation parameter indicating a correlation of the temperatures at the plurality of points is calculated, and whether or not to measure the measuring object (W) is determined on the basis of the relative evaluation parameter.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a measuring device, a measuring method, and a measurement control program, and more particularly to a measuring device, a measuring method, and a measurement control program for measuring the shape, roughness, contour, etc. of the surface of an object to be measured. [Background technology]

[0002] Measuring devices are known for measuring the shape, roughness, contour, etc. of the surface of a measurement object (workpiece). Such measuring devices are equipped with a mechanism whose parameters change with temperature (for example, thermal expansion). Furthermore, the parameters of the measurement object may also change with temperature. If the parameters of the measuring device or the measurement object change with temperature, the measurement results of the measurement object will fluctuate.

[0003] In order to reduce the effect of temperature changes on the measurement results of a measurement object, a shape measuring device has been proposed that uses temperature data detected by a temperature sensor to correct the driving program of the measuring device or the measurement results. For example, Patent Document 1 discloses that temperature sensor detection units are attached to each component of a coordinate measuring machine and to the measurement object, and temperature data acquired by the temperature sensors is used to perform temperature correction processing on the actual dimensions of the measurement object or the measurement operation of the coordinate measuring machine (changing the stop position of each drive unit during the measurement operation). In Patent Document 1, the temperature correction processing described above makes it possible to obtain the dimensions of the measurement object at a reference temperature (e.g., 20°C). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-090427 Summary of the Invention [Problem to be solved by the invention]

[0005] When performing temperature correction in a measurement device, in order to accurately evaluate changes in parameters (e.g., thermal expansion) due to temperature changes in each component of the measurement device, it is necessary to accurately detect temperature changes in each component at locations where the temperature changes are likely to have an effect. Here, a location where the temperature changes are likely to have an effect is, for example, a location in a component included in the measurement device where thermal expansion occurs due to factors such as the positional relationship with the heat source or heat exhaust unit, the material, shape, or thermal expansion coefficient, and which may affect the measurement results of the object being measured. In order to accurately detect temperature changes in locations where the temperature changes are likely to have an effect, it is preferable to install a temperature sensor directly in the location where the temperature changes are likely to have an effect.

[0006] However, there are cases where it is not possible to directly install a temperature sensor due to physical factors within the measuring device, etc. For example, in the case of a component that slides against other components, the temperature sensor cannot be installed in a position where it will interfere with other components.

[0007] When it is not possible to directly install a temperature sensor in a location susceptible to temperature changes, it is possible to install a temperature sensor in a location near the location susceptible to temperature changes and where a temperature sensor can be installed. However, there is a possibility that the temperature may differ between the location susceptible to temperature changes and the location where the temperature sensor is installed. For example, the temperature difference between the location susceptible to temperature changes and the system where the temperature sensor is installed may be due to differences in heat capacity and temperature change response between the two. If a temperature difference occurs between the location susceptible to temperature changes and the location where the temperature sensor is installed, the accuracy of temperature correction will decrease, and the accuracy of measurement of shape, roughness, contour, etc. will decrease.

[0008] The present invention has been made in consideration of the above circumstances, and aims to provide a measurement device, a measurement method, and a measurement control program that can ensure measurement accuracy even in a measurement environment where temperature changes occur. [Means for solving the problem]

[0009] A measuring device according to a first aspect of the present invention is a measuring device equipped with a detector for measuring an object to be measured, and is equipped with temperature sensors installed at multiple locations on the measuring device, and a control unit that calculates a relative evaluation parameter indicating the correlation between the temperatures at the multiple locations based on the temperatures at the multiple locations determined based on the output from the temperature sensors, and determines whether or not to measure the object to be measured based on the relative evaluation parameter.

[0010] In the measurement device according to the second aspect of the present invention, in the first aspect, the control unit calculates the rate of temperature change at multiple locations as a relative evaluation parameter, and determines to measure the object to be measured if the rate of temperature change at multiple locations is within a specified range.

[0011] In the measurement device according to the third aspect of the present invention, in the first or second aspect, the control unit calculates the temperature difference between temperatures at multiple locations as a relative evaluation parameter, and determines to measure the object to be measured if the temperature difference is within a specified range.

[0012] A measuring device according to a fourth aspect of the present invention is any of the first to third aspects, in which the temperature sensor is installed on at least several of the object to be measured, a scale for measuring the displacement of a stylus portion provided on the detector so as to be swingable around a swing center according to the shape of the object to be measured, and a scale for measuring the position of the detector.

[0013] A measurement method according to a fifth aspect of the present invention includes a step of calculating, by a control unit, a relative evaluation parameter indicating the correlation between temperatures at multiple locations based on temperatures at multiple locations determined based on outputs from temperature sensors installed at multiple locations in a measurement device, and a step of determining, by the control unit, whether or not to measure the object to be measured based on the relative evaluation parameter.

[0014] A measurement control program according to a sixth aspect of the present invention causes a computer to perform the following functions: calculating a relative evaluation parameter indicating the correlation between temperatures at multiple locations based on temperatures at multiple locations determined based on outputs from temperature sensors installed at multiple locations in a measurement device; and determining whether or not to measure an object to be measured based on the relative evaluation parameter. [Effects of the Invention]

[0015] According to the present invention, by using relative evaluation parameters, it is possible to ensure measurement accuracy even in a measurement environment where temperature changes occur. [Brief explanation of the drawings]

[0016] [Figure 1] 1 is a diagram showing a measurement device according to an embodiment of the present invention; [Figure 2] FIG. 2 is a block diagram showing a control device of the measurement device. [Figure 3] FIG. 10 is a perspective view for explaining thermal expansion of the scale of the detector. [Figure 4] 6 is a graph showing the response of each part to changes in environmental temperature. [Figure 5] FIG. 10 is a diagram illustrating an example of measurement environment determination. [Figure 6] 10 is a flowchart showing a first embodiment of measurement control. [Figure 7] 10 is a flowchart showing a second embodiment of measurement control. DETAILED DESCRIPTION OF THE INVENTION

[0017] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

[0018] [Measuring equipment] 1 is a diagram showing a measurement device according to one embodiment of the present invention. In the following description, a three-dimensional Cartesian coordinate system is used in which the XY plane is the horizontal plane and the Z direction is the vertical direction (perpendicular direction).

[0019] The measuring device 1 is a device for measuring the shape, roughness, contour, etc. of the surface of a measuring object W placed on a measuring object placement section (hereinafter referred to as a stage) 50.

[0020] 1, the stage 50 is placed on a base 52, and the surface of the stage 50 (the surface on which the measurement target W is placed) is parallel to the XY plane. A column (Z axis) 54 extending approximately perpendicular to the surface of the stage 50 is placed on the base 52. A carriage (X axis) 56 is attached to the column 54, and the carriage 56 is movable in the Z direction along the column 54 by an actuator (not shown).

[0021] The detector 10 is attached to the carriage 56, and the detector 10 is movable in the X direction relative to the carriage 56 by an actuator (not shown). A scale 58 for detecting the X direction position of the detector 10 is attached to the carriage 56. The scale 58 is, for example, a linear scale (linear position scale) with scale graduations formed along its length.

[0022] In this embodiment, the detector 10 is movable relative to the column 54, but the present invention is not limited to this. For example, the column 54 may be movable along the X direction relative to the stage 50, or the stage 50 may be movable along the X or Z direction relative to the column 54. That is, it is sufficient that the measurement object W placed on the stage 50 and the detector 10 are configured to be relatively movable in the X and Z directions. Furthermore, the detector 10 may be configured to be relatively movable not only in the X direction but also in the Y direction relative to the measurement object W placed on the stage 50.

[0023] As shown in Fig. 1, the detector 10 includes a stylus part 14, an arm part 16, a swing shaft 20, a scale 22, and a scale head 24. Note that Fig. 1 shows the shapes of the stylus part 14, the arm part 16, etc. in a simplified manner.

[0024] The stylus unit 14 is fixed to the arm unit 16 so as to extend in the X direction. Hereinafter, the stylus unit 14 attached to the arm unit 16 will be referred to as the swing unit 18. The swing unit 18 is attached to the detector housing 26 so as to be swingable integrally around a swing shaft 20. The mounting angle of the detector 10 relative to the carriage 56 is adjusted so that the swing shaft 20 is approximately parallel to the XY plane.

[0025] The configuration of the swinging part 18 is not limited to the example shown in Fig. 1. For example, the stylus part 14 or the arm part 16 may have an L-shaped bent part, and the stylus part 14 and the arm part 16 may be attached so as to be approximately parallel to each other.

[0026] A stylus 12 is provided at the tip of the stylus unit 14. The stylus 12 extends downward (in the -Z direction) in the figure. When the stylus 12 is brought into contact with the surface of the measurement object W placed on the stage 50 with a predetermined pressure, the oscillating unit 18 oscillates around the oscillating axis 20 according to the height and unevenness of the surface of the measurement object W at the contact position.

[0027] The configuration of the stylus unit 14 is not limited to the example shown in Fig. 1. For example, the stylus unit 14 may be a T-shaped stylus with styluses provided in the vertical direction in the figure, or an L-shaped stylus with a stylus that protrudes downward in the figure longer than in the example shown in Fig. 1.

[0028] The scale 22 is, for example, an arc scale (angle scale) formed in a substantially arc shape along the swing direction of the arm portion 16. The scale 22 has scale graduations formed along its length direction (displacement detection direction). The scale 22 is fixed to the base end of the arm portion 16 and is capable of swinging integrally with the swinging portion 18.

[0029] The swinging portion 18 is attached to the detector housing 26 via a swinging shaft 20 , and a scale head 24 is fixed to face the base end of the arm portion 16 .

[0030] The scale head 24 is a device that reads the graduations at the opposing position of the scale 22 fixed to the arm portion 16. As the scale head 24, for example, a photoelectric sensor or a non-contact sensor that includes an imaging element and an illumination light source (for example, an LED (Light-Emitting Diode)) for reading the graduations of the scale 22 can be used. Note that the type of the scale head 24 is not limited to the above.

[0031] The reading of the graduations of the scale 22 read by the scale head 24 is output to the control unit 102 of the control device 100 (see FIG. 2).

[0032] The control unit 102 controls the actuators provided on the column 54 and carriage 56 to move the measurement object W and the stylus 12 of the detector 10 relative to each other, while acquiring the readings of the graduations on the scale 22 for each position on the surface of the measurement object W. This makes it possible to measure the shape, roughness, contour, etc. of the surface of the measurement object W.

[0033] In this embodiment, the scale 22 is fixed to the base end of the arm portion 16, and the scale head 24 is fixed to the detector housing 26, but the present invention is not limited to this. For example, the scale 22 may be fixed to the detector housing 26, and the scale head 24 may be fixed to the base end of the arm portion 16. Furthermore, the scale 22 is not limited to an arc scale, and may be, for example, a linear scale (linear position scale).

[0034] Temperature sensors 80, 82, and 84 are temperature sensors capable of measuring the temperatures of the components (measurement object W, scale 22, and scale 58, respectively) of measurement device 1. In the example shown in Fig. 1, temperature sensor 80 is disposed near stage 50, temperature sensor 82 is disposed near scale 22 inside detector housing 26, and temperature sensor 84 is disposed near scale 58 on carriage 56, but the installation locations of temperature sensors 80, 82, and 84 are not particularly limited. Note that, for example, radiation temperature sensors or color temperature sensors may be used as temperature sensors 80, 82, and 84.

[0035] The measurement device 1 is provided with a control device 100. The control device 100 controls each part of the measurement device 1 to measure the measurement target W. The control device 100 also controls the temperature data D detected by the temperature sensors 80, 82, and 84. 80 , D 82 and D 84 and performs a measurement execution determination, which will be described later. Then, the control device 100 performs measurement of the measurement object W when it determines that the measurement environment is a normal (OK) environment suitable for measuring the measurement object W. When measuring the measurement object W, correction of the measurement result (temperature correction) is performed based on the temperatures of the measurement object W, the scale 22, and the scale 58. Note that the temperature correction is not limited to correction of the measurement result. For example, drive control and position control of the detector 10, etc. may be performed based on the temperatures of the measurement object W, the scale 22, and the scale 58.

[0036] 2 is a block diagram showing the control device 100 of the measurement device 1. As shown in FIG. 2, the control device 100 includes a control unit 102, an input unit 104, a display unit 106, and a storage 108.

[0037] The control unit 102 includes a processor (e.g., a CPU (Central Processing Unit) or an MPU (Micro-Processing Unit)) for controlling each part of the measuring device 1, and memory (e.g., a ROM (Read Only Memory), a RAM (Random Access Memory)). In response to an operation input from the input unit 104, the control unit 102 outputs control signals for controlling the control device 100 and the measuring device 1, and control signals for controlling an actuator for moving the detector 10, etc. The control unit 102 also has a measurement control function, a measurement execution determination function, and a temperature correction function.

[0038] The input unit 104 is a device for receiving operation input from an operator, and includes, for example, a keyboard, a mouse, a touch panel, and the like.

[0039] The display unit 106 is a device for displaying images and includes, for example, an LCD (Liquid Crystal Display). The display unit 106 displays, for example, a GUI (Graphical User Interface) for operating the control device 100, the measuring device 1, the actuator, etc., and measurement results such as the shape, roughness, or contour of the surface of the measurement target W.

[0040] The storage 108 is a device for storing a measurement control program for controlling the measurement device 1 and measurement result data, and includes, for example, a hard disk drive (HDD) or a solid state drive (SSD). 80 , D 82 and D 84 may be stored in storage 108.

[0041] The detector drive mechanism 60X includes an X-axis drive unit (for example, an actuator, not shown in FIG. 1) for moving the detector 10 in the X direction relative to the carriage 56.

[0042] The detector drive mechanism 60Z includes a Z-axis drive unit (for example, an actuator, not shown in FIG. 1) for moving the carriage 56 in the Z direction relative to the column 54, thereby moving the detector 10 in the Z direction.

[0043] When the stylus 12 comes into contact with the surface of the object W to be measured, the swinging unit 18 (arm unit 16) is displaced in the Z direction. The control unit 102 receives an input of a reading (scale head detection value) of the scale 22 by the scale head 24. The control unit 102 also receives an input of a reading (scale detection value) of the scale 58 indicating the amount of movement of the detector 10 in the X direction. The control unit 102 then uses the scale head detection value and the scale detection value to perform calculations on the shape, roughness, contour, etc. of the surface of the object W to be measured. The control unit 102 also receives temperature data D detected by the temperature sensors 80, 82, and 84. 80 , D 82and D 84 are acquired, and measurement execution determination and temperature correction are performed.

[0044] 2, the control device 100 of the measuring device 1 has the measurement execution determination function and the temperature correction function, but the present invention is not limited to this. The measurement execution determination function and the temperature correction function may be provided in a device separate from the control device 100 of the measuring device 1.

[0045] [Measurement execution determination function] The control unit 102 according to this embodiment monitors the operation of the temperature sensors 80, 82, and 84 incorporated in each component of the measurement device 1. The control unit 102 then determines whether or not the measurement environment is suitable for measuring the measurement object W, and performs measurement of the measurement object W only if the measurement environment is suitable. This measurement execution determination function is realized by a measurement control program provided in the control device 100 (an example of a computer).

[0046] 1, in this embodiment, the temperature sensors 80, 82, and 84 are installed near the measurement object W, the detector 10 including the scale 22, and the carriage 56 including the scale 58 and the detector drive mechanism 60. Specifically, the control unit 102 converts the temperature data D detected by the temperature sensors 80, 82, and 84 into 80 , D 82 and D 84 The temperature characteristics of each part are obtained and a measurement decision is made taking into consideration (for example, the temperature difference between the actual installation locations of the temperature sensors 80, 82, and 84 and the location to be measured, the ability to follow temperature changes in the measurement environment in which the measurement device 1 is installed, etc.).

[0047] (Detector drive mechanism) The detector drive mechanism 60X includes an X-axis drive unit for moving the detector 10 in the X direction along the carriage 56. A scale 58 is attached to the carriage 56 in the range in which the detector 10 moves, and the entire range in which the scale 58 is attached is structured to thermally expand.

[0048] Since it is difficult to attach the temperature sensor 84 directly to the scale 58, in practice the temperature sensor 84 is attached to a component near the scale 58. Therefore, the temperature sensor 84 cannot directly acquire the temperature of the scale 58. Therefore, a discrepancy occurs between the temperature detected by the temperature sensor 84 and the actual temperature of the scale 58.

[0049] The carriage 56 has a large space for accommodating the scale 58 and the detector drive mechanism 60X, and a cover that covers this space causes a difference between the ambient temperature of the measurement environment in which the measurement device 1 is installed and the temperature of the space inside the carriage 56. The temperature of the space inside the carriage 56 gradually follows changes in the ambient temperature.

[0050] (detector) The locations in the detector 10 where thermal expansion occurs are the scale 22, the stylus part 14, and the stylus 12 attached to the stylus part 14. Since the above-mentioned locations are mechanisms that oscillate in the detector 10, it is difficult to directly attach a temperature sensor to them. For this reason, a temperature sensor 82 is incorporated into the circuit board portion near the detector 10.

[0051] Since the substrate near the detector 10 generates heat itself, the temperature sensor 82 may output a temperature higher than the temperatures at the locations listed above. In addition, the internal space of the detector 10 is closed by a cover. Therefore, the temperature of the scale 22 gradually follows the heat generation of the substrate.

[0052] 3 is a perspective view illustrating thermal expansion of the scale 22. When the environmental temperature is a reference temperature (for example, 20° C.), the center C of the arc-shaped scale 22 22 is the center of oscillation C of the oscillation shaft 20 20 Assume that it is consistent with

[0053] When the temperature of the detector 10 becomes higher than the reference temperature, as shown in FIG. 3, the arm portion 16 and the scale 22 thermally expand, and the center C of the scale 22A after the thermal expansion 22A is the center of oscillation C 20 It becomes out of sync.

[0054] (Measurement object) The measurement object W has the highest ability to follow changes in the environmental temperature because it is exposed at the installation location of the measurement device 1. Note that the ability of the measurement object W to follow changes in the environmental temperature depends on the heat capacity of the measurement object W itself.

[0055] (Adaptability to changes in ambient temperature) Fig. 4 is a graph showing the response of each part to changes in the environmental temperature. Fig. 4 shows the transition of the temperatures of the measurement object W, the detector 10, and the carriage 56 (detector drive mechanism 60X) when the environmental temperature is linearly decreased.

[0056] Since the measurement object W has the highest ability to follow changes in the environmental temperature, the temperature of the measurement object W decreases linearly in response to changes in the environmental temperature. Note that in Fig. 4, the graphs showing the environmental temperature and the temperature of the measurement object W are approximately parallel, but the slopes of the two graphs may differ depending on the heat capacity of the measurement object W, etc.

[0057] On the other hand, the temperature of the detector 10 rises due to heat generation from the substrate. Also, the detector 10 is less responsive to changes in the environmental temperature than the measurement object W. Therefore, the rate at which the temperature of the detector 10 decreases with a decrease in the environmental temperature is slower than that of the measurement object W (the slope of the graph is gentler).

[0058] 4, the carriage 56 (detector drive mechanism 60X) has lower responsiveness to changes in environmental temperature (the slope of the graph is gentler) than the detector 10. Therefore, when the environmental temperature starts to drop, the temperature of the detector 10 is higher than that of the carriage 56 due to the influence of heat generated by the substrate, but over time the temperature of the detector 10 may become lower than that of the carriage 56.

[0059] (Measurement decision taking into account temperature characteristics) The control unit 102 determines whether the measurement environment is suitable for measuring the measurement object W based on the outputs of the temperature sensors 80, 82, and 84.

[0060] However, as described above, when the location where the effect of thermal expansion is to be measured differs from the actual installation location of the temperature sensor (for example, scales 22 and 58 and temperature sensors 82 and 84), it is necessary to determine the possible temperatures at the location where the effect of thermal expansion is to be measured from the outputs of temperature sensors 82 and 84. When determining the possible temperatures at the location where the effect of thermal expansion is to be measured from the outputs of temperature sensors 82 and 84, it is necessary to consider the ability of measurement device 1 to respond to temperature changes in the measurement environment in which it is installed.

[0061] Here, when the temperatures obtained from the outputs of the plurality of temperature sensors 80, 82, and 84 are individually evaluated to determine the measurement environment, it is conceivable to perform anomaly detection by setting upper and lower limit values ​​for the temperatures obtained from the outputs of the temperature sensors 80, 82, and 84. However, even if the temperatures obtained from the outputs of the temperature sensors 80, 82, and 84 are within the respective upper and lower limit values, there may be an anomaly when viewed from the system as a whole.

[0062] As an example, consider a case where the temperature obtained from the output of the temperature sensor 82 of the detector 10 is the "temperature that can be output when the ambient temperature is low," and the temperature obtained from the output of the temperature sensor 84 of the carriage 56 is the "temperature that can be output when the ambient temperature is high."

[0063] If the ambient temperature is low, it is thought that there is some kind of abnormality in the part that includes the carriage 56. However, if the "temperature that can be output when the ambient temperature is high" falls between the upper and lower limit values ​​set for the carriage 56, the carriage 56 alone is determined to be normal, and it is not possible to detect an abnormality by taking the entire system into consideration.

[0064] Therefore, the correlation between the measurement environment and the temperatures that can be assumed at each location where the effect of thermal expansion is to be measured (for example, the measurement object W, the detector 10, and the carriage 56 (detector drive mechanism 60X)) is to be determined in advance. Then, the measurement environment is determined using the correlation between the measurement environment and each location. This allows the measurement environment of the entire system to be taken into consideration when determining the measurement environment without installing additional temperature sensors, enabling more robust anomaly detection.

[0065] Specifically, a range is set for a relative evaluation parameter that indicates the correlation between temperatures determined from the outputs of the temperature sensors 80, 82, and 84 provided on the measurement object W, the detector 10, and the carriage 56, respectively. Then, the control unit 102 performs measurement of the measurement object W only when the parameter indicating the correlation falls within the specified range.

[0066] In the example shown in FIG. 5, the temperature difference ΔT ** (°C), or the temperature gradient ∇T obtained from the temperature sensors 80, 82, and 84 * (℃ / hour) is used.

[0067] Here, the temperature difference ΔT ** (°C) is a parameter that indicates the difference in temperature obtained from the outputs of two temperature sensors. Temperature difference ΔT ** As the temperature (°C), a simple difference, an absolute value of the difference, or the square of the difference may be used.

[0068] In the example shown in FIG. 5, the temperature difference ΔT between the measurement object W and the detector 10 DW is 4 to 10°C, and the temperature difference ΔT between the measurement object W and the carriage 56 WK is 2 to 5°C, and the temperature difference ΔT between the detector 10 and the carriage 56 DK If the temperature difference ΔT is within the range of 0 to 4°C, the control unit 102 determines that there is no abnormality. **By using (℃), it is possible to detect abnormalities such as the coexistence of a component with a temperature that can be output when the ambient temperature is low and a component with a temperature that can be output when the ambient temperature is high.

[0069] Also, the temperature gradient ∇T * (℃ / hour) is the rate of temperature change per unit time, i.e., the rate of temperature change (rising or falling). * (° C. / hour) is a parameter that depends on the heat capacity of each part (measurement object W, detector 10, and carriage 56), the temperature follow-up ability of each part to changes in the environmental temperature, or the relationship with the heat source.

[0070] The temperature gradient ∇T in the measurement object W, the detector 10, and the carriage 56 W , ∇T D and ∇T K The specified values ​​of ∇T W = 4℃ / hour, ∇T D = 3℃ / hour and ∇T K = 2℃ / hour. ∇T W , ∇T D and ∇T K If ∇T is within a predetermined range including the specified value (for example, a range of ± a few percent), the control unit 102 determines that there is no abnormality. W , ∇T D and ∇T K If the temperature gradient ∇T is outside a predetermined range including the specified value, for example, if the temperature gradient indicating the rate of temperature change is larger than the predetermined range (the temperature change is fast), it is possible that there is a component receiving excessive heat, and if the temperature gradient is smaller than the predetermined range (the temperature change is slow), it is possible that there is a factor hindering the supply of heat compared to the normal state. In this case, the control unit 102 determines that there is an abnormality. As described above, the temperature gradient ∇T * By using (℃ / hour), it is possible to detect abnormalities that are difficult to detect by determining individual temperatures. Also, when using a temperature gradient, it is possible to detect abnormalities such as the coexistence of a component with a "temperature that can be output when the ambient temperature is low" and a component with a "temperature that can be output when the ambient temperature is high."

[0071] (Comparative Example) As described above, when detecting an abnormality by setting upper and lower limits for the temperatures obtained from the outputs of the temperature sensors 80, 82, and 84, in an environment where the environmental temperature changes, it is necessary to widen the range of the upper and lower limits according to the range of the change in the environmental temperature. For example, when the temperature T of the measurement object W, the detector 10, and the carriage 56 is W , T D and T K The range of each is set to 0 to 50°C. In this case, the temperature T W , T D and T K As long as each of these values ​​falls within the above range, the measurement environment will be judged to be normal.

[0072] In contrast, in this embodiment, the temperature difference ΔT ** (℃) or temperature gradient ∇T * By using the relative evaluation parameter (°C / hour), the measurement environment can be judged more strictly, thereby ensuring the accuracy of the measurement results of the measurement object W.

[0073] (Variation) In this embodiment, the relative evaluation parameter is the temperature difference ΔT ** (℃) or temperature gradient ∇T * (°C / hour) was used, but the present invention is not limited to this. For example, the temperature difference ΔT ** (℃) and temperature gradient ∇T * (℃ / hour) and the temperature difference ΔT ** (℃) or temperature gradient ∇T * Instead of or in addition to (°C / hour), another relative evaluation parameter (for example, the temperature difference between the environmental temperature and the temperature obtained from the output of each temperature sensor 80, 82, and 84, a parameter for comparing the rate of change of the environmental temperature with the rate of change of the temperature obtained from the output of each temperature sensor 80, 82, and 84 (for example, the ratio of the temperature change rates)) may be used.

[0074] Furthermore, in this embodiment, the determination as to whether or not to perform measurement is made using temperature data in the vicinity of the measurement object W, scale 22, and scale 58, but the present invention is not limited to this. The installation locations of the temperature sensors used for the determination as to whether or not to perform measurement are not limited to those described above, and may be determined, for example, according to the specific configuration of the measurement device 1 (for example, the positional relationship between the heat source and the oscillating unit 18, scales 22 and 58, etc., which may affect the measurement results, temperature response characteristics, etc.).

[0075] When the environmental temperature of the measurement environment fluctuates significantly, the user must determine the measurement environment themselves. Furthermore, the user must manually start and stop the measurement operation, which requires manpower and labor. Until now, there has been no device that automatically determines the measurement environment using the operation monitoring function of a temperature sensor or the like, and automatically switches the measurement operation on and off.

[0076] For this reason, it is difficult to set up a measuring device in a measurement environment where the environmental temperature fluctuates greatly from time to time, and the user must prepare an environment suitable for measurement. In addition, the product specifications of the measuring device are limited by the catalog specifications due to the constraints of the environmental temperature.

[0077] In contrast to this, according to this embodiment, the measurement environment can be determined automatically and accurately.

[0078] [First embodiment of measurement control] 6 is a flowchart showing a first embodiment of measurement control. In this embodiment, when the temperature sensors 80, 82, and 84 measure temperature, the following measurement environment determination process is carried out.

[0079] When temperature measurement is started, the control unit 102 determines the temperatures of the measurement object W, the detector 10, and the carriage 56 based on the outputs from the temperature sensors 80, 82, and 84. The control unit 102 then determines a temperature gradient that indicates the temperature change per unit time at each location.

[0080] If the temperature gradients of the various parts are within a specified range (step S10), the control unit 102 determines that the measurement environment is normal (OK). Then, the control unit 102 drives the detector 10 and other components to measure the measurement object W (step S12).

[0081] On the other hand, if the temperature gradient of each part is outside the specified range (step S10), the control unit 102 determines that the measurement environment is abnormal (NG). Then, the control unit 102 does not perform measurement of the measurement object W, but puts the device into a standby state for a certain period of time (step S14), and performs the determination of step S10 again after the standby state ends.

[0082] According to this embodiment, by detecting the temperature gradient when performing temperature measurement, it is possible to determine whether the measurement environment is suitable for measuring the object to be measured W, and once a suitable measurement environment is established, measurement of the object to be measured W can be automatically started.

[0083] [Second embodiment of measurement control] 7 is a flowchart showing a second embodiment of measurement control. In this embodiment, the following measurement environment determination process is periodically executed while the measurement device 1 is running.

[0084] When the measurement device 1 is started, the control unit 102 determines the temperatures of the measurement object W, the detector 10, and the carriage 56 based on the outputs from the temperature sensors 80, 82, and 84. The control unit 102 then determines the temperature difference between each of the parts.

[0085] If the temperature difference between each part is within a specified range (step S20), the control part 102 determines that the measurement environment is normal (OK) and outputs a message to that effect via the display part 106 (step S22). This allows the user to drive the detector 10 and the like to measure the measurement object W.

[0086] On the other hand, if the temperature difference between each part is outside the specified range (step S20), the control unit 102 determines that the measurement environment is abnormal (NG) and outputs a warning via the display unit 106 (step S24). DW , ΔT WK and ΔT DK Based on the above, it may be possible to output information about which component has had a temperature abnormality detected.

[0087] According to this embodiment, by periodically detecting the temperature difference, it is possible to reliably determine whether or not there is an abnormality in the measuring device 1.

[0088] The execution timing of the measurement environment determination process according to each of the above embodiments is not limited to the above. For example, it can be executed when the measurement device 1 is started up, after a predetermined time has elapsed since the measurement device 1 was started up, or at predetermined intervals, or when the measurement target W is placed on the stage 50. [Explanation of symbols]

[0089] 1...measuring device, 10...detector, 12...stylus, 14...stylus section, 16...arm section, 18...oscillating section, 20...oscillating axis, 22...scale, 24...scale head, 26...detector housing, 50...measurement object placement section, 52...surface plate, 54...column, 56...carriage, 58...scale, 60...detector drive mechanism, 80, 82, 84...temperature sensor, 100...control device, 102...control section, 104...input section, 106...display section, 108...storage

Claims

1. A measuring device equipped with a detector for measuring a measurement object, temperature sensors installed at multiple locations on the measuring device; a control unit that calculates a relative evaluation parameter indicating a correlation between the temperatures at the plurality of locations based on the temperatures at the plurality of locations obtained based on the outputs from the temperature sensor, and determines whether or not to perform measurement of the measurement object based on the relative evaluation parameter; A measuring device comprising:

2. 2. The measurement device according to claim 1, wherein the control unit calculates the rate of temperature change at the plurality of locations as the relative evaluation parameter, and determines to perform measurement of the measurement object if the rate of temperature change at the plurality of locations is within a specified range.

3. The measurement device according to claim 1 , wherein the control unit calculates a temperature difference between the temperatures at the plurality of locations as the relative evaluation parameter, and determines to perform measurement of the measurement object when the temperature difference is within a specified range.

4. 4. The measuring device according to claim 1, wherein the temperature sensor is installed on at least two or more of the object to be measured, a scale for measuring displacement of a stylus portion provided on the detector so as to be swingable around a swing center in accordance with a shape of the object to be measured, and a scale for measuring a position of the detector.

5. a step of calculating, by a control unit, a relative evaluation parameter indicating a correlation between temperatures at the plurality of locations based on temperatures at the plurality of locations determined based on outputs from temperature sensors installed at the plurality of locations of the measurement device; determining by the control unit whether or not to measure the object to be measured based on the relative evaluation parameters; A measurement method comprising:

6. a function of calculating a relative evaluation parameter indicating a correlation between temperatures at a plurality of locations on the measuring device based on temperatures at the plurality of locations determined based on outputs from temperature sensors installed at the plurality of locations; a function of determining whether or not to measure the measurement object based on the relative evaluation parameters; A measurement control program that causes a computer to execute the above.

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