Shape measuring device and computer-readable storage medium

Abstract

This shape measuring device: obtains the height of a surface of a measurement object from a distance sensor that moves relative to the surface of the measurement object; calculates coordinate values of a rising portion or falling portion present at the surface of the measurement object; stores reference values for the coordinate values of the rising portion or falling portion; compares said reference values with coordinate values calculated by a coordinate value calculation unit; determines coordinate values different from the reference values as being invalid data; changes speed conditions for the relative speed between the measurement object and the distance sensor; and determines a factor of the invalid data by making comparisons with coordinate values calculated according to different speed conditions.

Description

[Technical Field]

[0001] The present disclosure relates to a shape measurement device and a computer-readable storage medium. [Background technology]

[0002] Conventionally, there have been shape measurement devices that irradiate a measurement object with measurement light and measure the position of each part of the measurement object. For example, Patent Document 1 discloses such devices. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-137265 Summary of the Invention [Problem to be solved by the invention]

[0004] Some shape measurement devices store reference values ​​for the rise and fall of a signal and compare the measurement results with these reference values ​​to determine the accuracy of the shape of the object being measured. However, false detections can occur during shape measurement.

[0005] In the field of shape measurement, there is a need for a technique for determining the cause of false detection. [Means for solving the problem]

[0006] A shape measuring device according to one aspect of the present disclosure includes a coordinate value calculation unit that acquires the height of the surface of the object to be measured from a distance sensor that moves relative to the surface of the object to be measured, and calculates the coordinate values ​​of rising or falling edges on the surface of the object to be measured based on the height; a reference value memory unit that stores a reference value for the rising or falling coordinate value; a data comparison unit that compares the reference value with the coordinate value calculated by the coordinate value calculation unit; and a factor determination unit that determines that coordinate values ​​that differ from the reference value are invalid data, changes the speed conditions for the relative speed between the object to be measured and the distance sensor, compares the coordinate values ​​calculated under the different speed conditions, and determines the cause of the invalid data. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 2 is a block diagram of a shape measuring device. [Figure 2] FIG. 1 is a schematic diagram of a shape measuring device for measuring a linear measurement target. [Figure 3] FIG. 1 is a schematic diagram of a shape measuring device for measuring a circular measurement target. [Figure 4] FIG. 1 is a schematic diagram of linear coordinate values. [Figure 5] FIG. 1 is a schematic diagram of circular coordinate values. [Figure 6] FIG. 10 is a schematic diagram showing changes in coordinate values. [Figure 7] FIG. 10 is a schematic diagram of coordinate values ​​when chattering occurs. [Figure 8] FIG. 10 is a schematic diagram showing changes in coordinate values. [Figure 9] 10 is a flowchart illustrating the operation of the shape measuring device. [Figure 10] FIG. 2 is a hardware configuration diagram of the shape measuring device. DETAILED DESCRIPTION OF THE INVENTION

[0008] (First embodiment) The following describes a profile measuring device 100 according to a first embodiment. The profile measuring device 100 is applied to a machine that measures the unevenness of a measurement object, such as a gear measuring instrument. The profile measuring device 100 may also be applied to a control device of another device, such as a numerical control device, or an information processing device, such as a PC (personal computer). The configuration requirements of the profile measuring device 100 differ depending on the device to which it is applied. The components of the shape measuring device are classified by their functions, and do not necessarily have to be clearly distinguishable in terms of physical configuration and program configuration.

[0009] 1 is a block diagram of a form measuring device 100. The form measuring device 100 includes a motor drive unit 11, a motor control unit 12, a distance sensor 13, a coordinate value calculation unit 14, a reference value storage unit 15, a data comparison unit 16, a factor determination unit 17, and a factor notification unit 18.

[0010] The motor driving unit 11 drives the motor in accordance with commands from the motor control unit 12. The motor is provided with an encoder (not shown), which outputs the rotation angle of the motor.

[0011] The motor control unit 12 acquires the rotation angle of the motor and controls the rotation speed (rotation angle) of the motor. The motor control method differs depending on whether the measurement target (workpiece) is linear or circular. In the case of a linear measurement target, the rotational motion of the motor is converted into linear motion by a ball screw, as shown in Figure 2. Motor control unit 12 controls the relative position between distance sensor 13 and the measurement target (a table on which the measurement target is placed). In the case of a circular measurement target, the motor rotates the circular measurement target as shown in Fig. 3. The motor control unit 12 controls the rotation speed (rotation angle) of the motor obtained from the encoder.

[0012] The distance sensor 13 irradiates the measurement object with sound waves, light, or the like, and detects the height of the surface of the measurement object from the reflection from the measurement object.

[0013] The coordinate value calculation unit 14 calculates the coordinate values ​​of the rising and falling edges of the irregularities present on the surface of the measurement object based on the height of the surface of the measurement object detected by the distance sensor 13. The coordinate value calculation method uses existing technology.

[0014] The units of coordinate values ​​differ between linear and circular measurement targets. In the case of a linear measurement target, the position of the distance sensor relative to the measurement target is taken as the coordinate value. In the case of a circular measurement target, the motor angle is used as the coordinate value.

[0015] The reference value storage unit 15 stores reference coordinate values. The reference coordinate values ​​indicate positions where rising and falling edges exist on the surface of the measurement object. In this embodiment, the cross section of the linear measurement object is assumed to be rectangular for the sake of explanation, but may be trapezoidal or another shape.

[0016] The reference values ​​include the machine coordinates of the machine that measures the object, the relative coordinates with respect to the origin set on the machine coordinate system, and the distance (or angular difference) between the coordinates. Machine coordinates are unique coordinates that belong to the machine itself. Relative coordinates are coordinates that start from any point on the machine coordinate system. Inter-coordinate distance is the distance between two or more reference values ​​on the machine coordinate system. If the measurement object is circular, a point on the rotation axis is set as the origin. Relative coordinates are relative coordinates that start from any point on the rotation axis. The distance between coordinates is the distance between two or more reference values ​​on the rotation axis.

[0017] The reference values ​​can be calculated from the ideal original form of the measurement object, a design drawing of the measurement object, etc. For example, the ideal original form of the measurement object is measured, and the coordinate values ​​of the rising and falling edges are used as the reference values. The reference values ​​of the rising and falling edges can also be calculated from the design drawing. A tolerance may be set for the reference values. If a tolerance is set, the factor determination unit 17 determines that coordinate values ​​that exceed the tolerance are invalid data.

[0018] The data comparison unit 16 compares the rising and falling coordinate values ​​calculated by the coordinate value calculation unit 14 with the reference values ​​stored in the reference value storage unit 15. If the comparison shows that the rising and falling coordinate values ​​differ from the reference values, the data is determined to be invalid data.

[0019] If the data comparison unit 16 detects invalid data, the cause determination unit 17 sends a command to the motor control unit 12 to change the speed conditions of the motor and re-measure the coordinate values. If the same coordinate values ​​as the previous coordinate values ​​are detected as a result of changing the motor speed conditions, the factor determination unit 17 determines that the cause of the invalid data is a defective shape of the object to be measured.If the coordinate values ​​different from the previous coordinate values ​​are detected as a result of changing the motor speed conditions, the factor determination unit 17 determines that the cause of the invalid data is chattering.If the invalid data is not detected as a result of changing the motor speed conditions, the factor determination unit 17 determines that the cause of the invalid data is noise, speed conditions, etc.

[0020] The cause notification unit 18 notifies the user of the result of the determination made by the cause determination unit 17. The notification method may be an existing method.

[0021] Next, the operation of the shape measuring device 100 will be described using a linear measurement target as an example. Figure 4 is a schematic diagram of the shape measuring device 100 measuring a linear measurement target. The distance sensor 13 measures the height of the surface of the measurement target while moving parallel to the surface of the measurement target. The profile measuring device 100 detects the coordinate values ​​of the positions where rising and falling edges exist on the surface of the measurement object based on the height of the surface of the measurement object detected by the distance sensor 13. The reference value storage unit 15 stores the reference values ​​of the coordinate values ​​of the rising and falling edges. In Fig. 4, the reference values ​​of the coordinate values ​​are plotted as coordinate values ​​with the measurement start position of the distance sensor 13 as the origin, and as the distance between the coordinates of two points. The reference values, with the measurement start position of the distance sensor 13 as the origin, are the rising edges "3, 6, 9, ..." and the falling edges "4, 7, 10, ...". The reference value of the distance between coordinates is the distance between the rising edge and the falling edge "1, 2, 1, 2, 1, 3, ...". The reference value of the distance between coordinates may also be "all 1".

[0022] The data comparator 16 compares the reference values ​​with the coordinate values ​​(actual measurements) detected by the distance sensor. Assume that the actual measurements are "3, 4, 6, 7, 9, 10.1, ...." The data comparator 16 determines that the third falling coordinate value "10.1," which differs from the reference value, is invalid data.

[0023] When invalid data is detected, the factor determination unit 17 changes the motor speed conditions and starts measurement again. The factor determination unit 17 sends a command to the motor control unit 12. The distance sensor 13 calculates the coordinate values ​​at which rising and falling edges occur under the new speed conditions.

[0024] The cause determination unit 17 compares the coordinate values ​​of the rising and falling edges detected under the new speed conditions with the coordinate values ​​of the rising and falling edges detected under the previous speed conditions. If the coordinate values ​​of the invalid data detected under the new speed conditions differ from the coordinate value "10.1" of the invalid data detected previously, the cause determination unit 17 determines that the cause of the invalid data is chattering. If the coordinate value of the invalid data detected under the new speed conditions is the same as the coordinate value "10.1" of the invalid data detected previously, the factor determination unit 17 determines that a shape defect exists at the coordinate value "10.1". If the invalid data previously detected is not detected under the new speed condition, the cause determining unit 17 determines that the cause of the invalid data is noise, the speed condition, or the like.

[0025] Next, an example of measuring a circular measurement object will be described. Fig. 5 is a schematic diagram of a shape measuring device 100 that measures a circular measurement object. A distance sensor 13 irradiates the surface of the measurement object with a laser or the like. The measurement object rotates, and the laser measures the height of the surface of the measurement object. It is assumed that the measurement object in Fig. 5 has a defect at the "95 degree" position.

[0026] The reference value storage unit 15 stores reference values ​​for the rising and falling coordinate values. In the schematic diagram of FIG. 5, the reference values ​​for the coordinate values ​​are plotted as reference values ​​with a point on the rotation axis as the origin and the distance between the coordinates of two points on the rotation axis. The reference values ​​with a point on the rotation axis as the origin are the rising coordinate values ​​"0, 45, 90, 135, ..." and the falling coordinate values ​​"15, 60, 105, 150, ...". The reference values ​​for the distance between coordinates can be expressed, for example, as "tooth tip: 15, tooth interval: 30" or the angle between the rising and falling edges "15, 30, 15, 30, 15, ...".

[0027] Assume that when the measurement target is rotated at a certain speed, the distance sensor 13 detects rising coordinate values ​​"0, 45, 90, 100, 135, . . . " and falling coordinate values ​​"15, 60, 95, 105, 150, . . . ". The coordinate values ​​detected by the distance sensor 13 may be expressed as the angle difference between two points (tooth tip: 15, 5, tooth interval: 30, 5).

[0028] The factor determination unit 17 compares the reference values ​​with the coordinate values ​​detected by the distance sensor 13. The coordinate value "100" of the fourth rising edge and the coordinate value "95" of the third falling edge differ from the reference values. The factor determination unit 17 determines that the coordinate values ​​"100" and "95" that differ from the reference values ​​are invalid data.

[0029] If the cause determination unit 17 detects invalid data, it changes the speed conditions of the motor, causing the measurement object to rotate at a new speed, and measurement can be performed again under the new speed conditions.

[0030] The process of determining that the cause of the incorrect data is a defect will be described with reference to FIGS. The distance sensor 13 irradiates the surface of the measurement object with a laser or the like. The measurement object rotates, and the laser measures the height of the surface of the measurement object. Note that in the measurement object in Figure 5, there is a defect at the "95 degree" position.

[0031] The shape measuring device 100 rotates the object to be measured at a normal speed. At this time, the data comparison unit 16 compares the reference value with the coordinate value detected by the distance sensor 13, and determines that the third falling coordinate value "95" is invalid data. When the cause determination unit 17 detects invalid data, it changes the speed conditions of the motor.

[0032] FIG. 6 is a schematic diagram showing changes in coordinate values ​​when the speed condition of the measurement object is changed. In this example, the motor speed is slowed down. If the coordinate value of the invalid data does not change even when the motor speed condition is changed, the cause determination unit 17 determines that a defect exists at the position of the coordinate value where the invalid data occurs.

[0033] The process of determining that chattering is the cause of invalid data will be described with reference to FIGS. In the shape measuring instrument 100 of FIG. 7, chattering occurs in the distance sensor 13. Distance sensor 13 irradiates the surface of the measurement object with a laser or the like. The measurement object rotates, and the laser measures the height of the surface of the measurement object. When the measurement object is rotated at a certain speed, the distance sensor 13 detects rising coordinate values ​​"0, 0.4, 45, 45.4, 90, 90.4, . . . " and falling coordinate values ​​"0.2, 15, 45.2, 60, 90.2, 105, . . . ". The distance sensor 13 may detect the angle difference between two points (tooth tip: 15, 0.2, tooth interval: 30, 0.2) as a coordinate value.

[0034] The factor determination unit 17 compares the reference values ​​with the coordinate values ​​detected by the distance sensor. In the example of Fig. 7, the coordinate value of the second rising edge "0.4", the coordinate value of the fourth rising edge "45.4", the coordinate value of the sixth rising edge "90.4", the coordinate value of the first falling edge "0.2", the coordinate value of the third falling edge "45.2", and the coordinate value of the fifth falling edge "90.2" are different from the reference values. The factor determining unit 17 determines that these coordinate values ​​"0.2", "0.4", "45.2", "45.4", "90.2", and "90.4" are invalid data.

[0035] If the cause determination unit 17 detects invalid data, it changes the speed conditions of the motor. If the measurement object is circular, changing the speed conditions allows re-measurement.

[0036] FIG. 8 shows the change in coordinate values ​​when the speed conditions of the measurement object are changed. Suppose that when the measurement target is rotated at a certain speed, invalid data is detected at the first falling edge "0.2" and the second rising edge "0.4". When the cause determination unit 17 detects invalid data, it changes the motor speed conditions. In this example, the motor speed is slowed. If the motor speed is 0.2 degrees / ms when the chattering signal is 1 ms, invalid data will occur at the coordinate values ​​"0.2" and "0.4". If the motor speed is changed to 0.1 degrees / ms, invalid data will occur at the coordinate values ​​"0.1" and "0.2". The cause determining unit 17 changes the motor speed conditions, and when the coordinate values ​​of the invalid data change, determines that the cause of the invalid data is chattering.

[0037] If the invalid data at the coordinate values ​​"0.2" and "0.4" is no longer detected as a result of changing the speed conditions, the cause determining unit 17 determines that the cause of the invalid data is noise, the speed conditions, or the like.

[0038] Next, the operation of the profile measuring device 100 will be described according to the flowchart in Fig. 9. The profile measuring device 100 rotates the motor at a certain speed (step S1). The rotation of the motor causes the surface of the measurement object and the distance sensor 13 to move relative to each other. By moving the surface of the measurement object and the distance sensor 13 relative to each other, the coordinate values ​​of the position detected by the distance sensor 13 change. The distance sensor 13 measures the height of the surface of the measurement object (step S2). The profile measuring device 100 calculates the coordinate values ​​of the rising and falling edges of the surface of the measurement object (step S3), and compares the calculated coordinate values ​​with reference values ​​(step S4).

[0039] If the detected coordinate values ​​are the same as the reference values ​​(step S5; Same), it is determined that the measurement was successful (step S6), and the cause determination process is terminated. If the coordinate values ​​are different from the reference values ​​(step S5; Different), the shape measuring device 100 determines that the coordinate values ​​detected in step S3 are invalid data (step S7).

[0040] If invalid data is detected in step S7, the profile measuring device 100 changes the motor speed conditions (step S8). The profile measuring device 100 changes the motor speed and calculates coordinate values ​​(step S9). The profile measuring device 100 compares the coordinate values ​​of the invalid data calculated under the new speed conditions with the coordinate values ​​of the invalid data detected beforehand (step S10). If the coordinate values ​​of the invalid data detected under the new speed conditions are the same as the coordinate values ​​of the invalid data detected beforehand (step S11; same), the profile measuring device 100 determines that the cause of the invalid data is the shape of the measurement object (step S12) and ends the cause determination process.

[0041] If the coordinate values ​​of the invalid data detected under the new speed conditions differ from the coordinate values ​​of the invalid data detected beforehand (step S11; different), the shape measuring device 100 determines that the cause of the invalid data is chattering (step S13).

[0042] If invalid data is not detected by changing to a new speed condition (step S11; not detected), the shape measuring device 100 determines that the cause of the invalid data is other factors such as noise or speed conditions (step S14).

[0043] As described above, when the form measuring apparatus 100 of this embodiment detects invalid data that differs from the reference value, it changes the motor speed and performs measurement again. If the coordinate value of the position where the invalid data occurred does not change as a result of changing the motor speed, it determines that a form defect (such as a defect) exists at the position where the invalid data occurred.

[0044] If the coordinate value of the position where the invalid data occurred changes, the form measuring instrument 100 determines that chattering has occurred. Chattering changes depending on the motor speed.

[0045] If the remeasurement does not result in any incorrect data, the shape measurement device 100 determines that the incorrect data has been generated due to other factors such as noise or speed conditions.

[0046] According to the form measuring device 100 of the present disclosure, the cause of the incorrect data can be evaluated, thereby improving the accuracy of the measurement. Furthermore, since the cause of the incorrect data can be automatically identified, the number of measurements and the measurement time can be reduced.

[0047] The hardware configuration of the shape measuring device 100 to which the present disclosure is applied will be described below. Fig. 10 is a hardware configuration diagram of the shape measuring device 100. As shown in Fig. 10, the shape measuring device 100 includes a CPU 111 that controls the overall shape measuring device 100, a ROM 112 that records programs and data, and a RAM 113 for temporarily expanding data, and the CPU 111 reads out a system program recorded in the ROM 112 via a bus and executes shape measurement processing in accordance with the system program.

[0048] The nonvolatile memory 114 is backed up by, for example, a battery (not shown), and the stored state is maintained even when the power to the form measuring device 100 is turned off. The nonvolatile memory 114 stores various data such as programs read from the external device 120 via the interfaces 115, 118, and 119, and user operations input via the input unit 30. The nonvolatile memory 114 may also store programs and data for executing the form measuring device 100 of this embodiment. The display unit 70 also displays various data, measurement results, causes of invalid data, etc.

[0049] The interface 115 is an interface for connecting the shape measuring device 100 to an external device 120 such as an adapter. Programs, various parameters, etc. are read from the external device 120 side. The interface 118 is an interface for connecting the shape measuring device 100 to a display unit 70 such as a liquid crystal display. The display unit 70 displays various data loaded into memory, data obtained as a result of executing programs, etc. The interface 119 is an interface for connecting the shape measuring device 100 to an input unit 30 such as a keyboard, a pointing device, etc. The input unit 30 passes commands, data, etc. based on operations by an operator to the CPU 111 via the interface 119.

[0050] Although the present disclosure has been described in detail, the present disclosure is not limited to the individual embodiments described above. Various additions, substitutions, modifications, partial deletions, etc. are possible in these embodiments without departing from the gist of the present disclosure or the gist of the present disclosure derived from the claims and their equivalents. Furthermore, these embodiments can also be implemented in combination. For example, in the above-described embodiments, the order of each operation and the order of each process are shown as examples and are not limited to these.

[0051] The following additional notes are provided regarding the above-described embodiment and modifications. (Appendix 1) The shape measuring device (100) includes a coordinate value calculation unit (14) that acquires the height of the surface of the object to be measured from a distance sensor (13) that moves relative to the surface of the object to be measured, and calculates the coordinate value of a rising or falling edge on the surface of the object to be measured based on the height; a reference value memory unit (15) that stores a reference value for the coordinate value of the rising or falling edge; a data comparison unit (16) that compares the reference value with the coordinate value calculated by the coordinate value calculation unit; and a factor determination unit (17) that determines that coordinate values ​​that differ from the reference value are invalid data, changes the speed conditions for the relative speed between the object to be measured and the distance sensor, compares the coordinate values ​​calculated under the different speed conditions, and determines the cause of the invalid data. (Appendix 2) If the coordinate values ​​calculated under the different speed conditions are the same, the factor determining unit (17) determines that the cause of the incorrect data is the shape of the measurement object. (Appendix 3) If the coordinate values ​​calculated under the different speed conditions are different, the cause determining unit (17) determines that the cause of the incorrect data is chattering of the distance sensor. (Appendix 4) If the invalid data is not detected as a result of changing the speed condition, the factor determining unit (17) determines that the cause of the invalid data is noise or the speed condition. (Appendix 5) The coordinate values ​​in the shape measuring device (100) are at least one of machine coordinates, relative coordinates with respect to an arbitrary reference point, and distances between the coordinates of at least two or more points. (Appendix 6) The reference values ​​of the coordinate values ​​in the shape measuring device (100) are calculated from at least one of an ideal original shape of the measurement object and a design drawing of the measurement object. (Appendix 7) The shape measuring device (100) includes a notification unit that notifies the user of the cause of the incorrect data. (Appendix 8) A storage medium (112, 113, 114) stores instructions readable by one or more processors (111) that are executed to acquire the height of the surface of the object to be measured from a distance sensor (13) that moves relative to the surface of the object to be measured, calculate coordinate values ​​of rising or falling edges on the surface of the object to be measured based on the height, compare a reference value of the coordinate value of the rising or falling edge with the coordinate value of the rising or falling edge on the surface of the object to be measured, determine that coordinate values ​​that differ from the reference value are invalid data, change speed conditions for the relative speed between the object to be measured and the distance sensor, compare the coordinate values ​​calculated under different speed conditions, and determine the cause of the invalid data. [Explanation of symbols]

[0052] 100 Shape measuring device 13 Distance Sensor 14 Coordinate value calculation unit 15 Reference value storage section 16 Data comparison section 17 Factor determination section 18. Cause notification section 111 CPU 112 ROM 113 RAM 114 Non-volatile memory

Claims

1. a coordinate value calculation unit that acquires the height of the surface of the measurement object from a distance sensor that moves relatively to the surface of the measurement object, and calculates the coordinate value of a rising or falling edge that exists on the surface of the measurement object based on the height; a reference value storage unit that stores a reference value of the rising or falling coordinate value; a data comparison unit that compares the reference value with the coordinate value calculated by the coordinate value calculation unit; a factor determination unit that determines that coordinate values ​​that differ from the reference values ​​are invalid data, changes a speed condition of the relative speed between the measurement object and the distance sensor, compares the coordinate values ​​calculated under the different speed conditions, and determines the cause of the invalid data; A shape measuring device comprising:

2. 2. The shape measuring device according to claim 1, wherein if the coordinate values ​​calculated under the different speed conditions are the same, the cause determining unit determines that the cause of the incorrect data is the shape of the object to be measured.

3. 2. The shape measuring device according to claim 1, wherein if the coordinate values ​​calculated under the different speed conditions are different, the cause determining unit determines that the cause of the incorrect data is chattering of the distance sensor.

4. 2. The shape measuring device according to claim 1, wherein, when the incorrect data is not detected as a result of changing the speed condition, the cause determining unit determines that the cause of the incorrect data is noise or a speed condition.

5. 2. The shape measuring instrument according to claim 1, wherein the coordinate values ​​are at least one of machine coordinates, relative coordinates with respect to an arbitrary reference point, and distances between coordinates of at least two or more points.

6. 2. The shape measuring instrument according to claim 1, wherein the reference values ​​of the coordinate values ​​are calculated from at least one of an ideal original shape of the object to be measured and a design drawing of the object to be measured.

7. The shape measuring device according to claim 1 , further comprising a notification unit that notifies a user of the cause of the invalid data.

8. When executed by one or more processors, acquiring a height of the surface of the object to be measured from a distance sensor that moves relative to the surface of the object to be measured, and calculating a coordinate value of a rising edge or a falling edge present on the surface of the object to be measured based on the height; comparing a reference value of the coordinate value of the rising or falling edge with a coordinate value of the rising or falling edge present on the surface of the measurement object; determining that coordinate values ​​that differ from the reference values ​​are invalid data, changing the speed conditions of the relative speed between the object to be measured and the distance sensor, comparing the coordinate values ​​calculated under the different speed conditions, and determining the cause of the invalid data; A storage medium that stores instructions readable by the processor.

Images