Measuring equipment

Abstract

A measurement device according to the present disclosure comprises: a coordinates value calculation unit for calculating, on the basis of a signal inputted from a measurement instrument, a coordinate value of a position at which the shape of a measurement surface of an object under measurement changes; a measurement information recording unit for recording measurement information concerning the time interval at which the shape of the measurement surface of the object under measurement changes; and a speed improperness determining unit for determining, if the time interval at which the shape of the measurement surface of the object under measurement changes as recorded by the measurement information recording unit is shorter than a prescribed first threshold defined in advance, that the relative speed between the measurement surface of the object under measurement and the measurement instrument is improper. Upon determining that the relative speed is improper, the measurement device communicates that the evaluation of the measurement surface of the object under measurement is not being correctly carried out.

Description

[Technical Field]

[0001] The present disclosure relates to a measurement device. [Background technology]

[0002] There is a technology for evaluating shape by analyzing a signal input from a measuring device and calculating the coordinate values ​​at the rising and falling edges of the signal (for example, Patent Document 1). This technology is used, for example, when machining a workpiece such as a gear with an uneven surface, to detect the rising and falling edges of the gear teeth and evaluate the shape of the gear teeth. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2020-055072 Summary of the Invention [Problem to be solved by the invention]

[0004] When measuring the shape of a measurement object, increasing the relative speed between the measurement surface of the measurement object and the measuring instrument can shorten the cycle time for evaluating the shape of the measurement surface of the measurement object. For example, when evaluating the shape of gear teeth, increasing the rotational speed of the gear when measuring the unevenness of the teeth with the measuring instrument can shorten the cycle time for evaluating the gear shape. However, a certain processing time is required for the measuring device to analyze the signal from the measuring instrument and calculate the coordinate values ​​of the rising and falling positions of the teeth. Therefore, if rising and falling edges occur consecutively within the processing time for coordinate value calculation, it may not be possible to accurately calculate each coordinate value. Therefore, it is desirable to be able to determine whether the relative speed between the measurement surface of the measurement object and the measuring device is being controlled in accordance with the processing capacity of the measuring device. [Means for solving the problem]

[0005] The measuring device disclosed herein determines whether the relative speed between the measuring device and the measurement surface of the measurement target is appropriate based on the processing capacity and measurement information of the measuring device. The problem is solved by monitoring the signal input from the measuring device and determining whether the coordinate values ​​of the position where the shape of the workpiece changes can be correctly calculated at the current speed.

[0006] One aspect of the present disclosure is a measurement device comprising: a coordinate value calculation unit that calculates coordinate values ​​of a position where the shape of the measurement surface has changed based on a signal input from a measuring instrument that moves the relative position of the measurement surface of the object to measure changes in the shape of the measurement surface; a measurement information recording unit that records measurement information related to the time interval at which a shape change occurs on the measurement surface of the object to be measured; and a speed incorrectness determination unit that determines that the relative speed between the measurement surface of the object to be measured and the measuring instrument is incorrect if the time interval at which a shape change occurs on the measurement surface of the object to be measured recorded by the measurement information recording unit is shorter than a predetermined first threshold value, and if the speed incorrectness determination unit determines that the relative speed between the measurement surface of the object to be measured and the measuring instrument is incorrect, it notifies the user that the measurement surface of the object to be measured has not been correctly evaluated. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a schematic hardware configuration diagram of a measurement device according to a first embodiment of the present disclosure. [Figure 2] FIG. 1 is a schematic diagram illustrating measurement of a gear shape using the measuring device according to the present embodiment. [Figure 3] FIG. 1 is a block diagram showing schematic functions of a measurement device according to a first embodiment of the present disclosure. [Figure 4] 10 is a graph showing an example of a series of distance data calculated based on a signal input from a measuring device. [Figure 5] 10 is a graph showing another example of a series of distance data calculated based on a signal input from a measuring device. [Figure 6] FIG. 10 is a block diagram showing schematic functions of a measurement device according to a second embodiment of the present disclosure. [Figure 7] 1 is a schematic diagram illustrating measurement of the surface shape of a workpiece using the measuring device according to the present embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008] [First embodiment] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. 1 is a schematic hardware configuration diagram showing the main parts of a measuring device according to a first embodiment of the present disclosure. In this embodiment, a measuring device 1 that measures the rising and falling positions of a gear tooth as a measurement target will be described as an example.

[0009] The CPU 11 provided in the measuring device 1 according to this embodiment is a processor that controls the entire measuring device 1. The CPU 11 reads a system program stored in the ROM 12 via the bus 22 and controls the entire measuring device 1 in accordance with the system program. The RAM 13 temporarily stores temporary calculation data, display data, various data input from outside, and the like.

[0010] The nonvolatile memory 14 is composed of, for example, a battery-backed memory (not shown) or an SSD (Solid State Drive), and retains its stored state even when the power to the measuring device 1 is turned off. The nonvolatile memory 14 stores programs and data read from an external device 32 via the interface 15, programs and data input via the input device 31, data calculated based on signals input from the measuring instrument 35, and the like. The programs and data stored in the nonvolatile memory 14 may be expanded into the RAM 13 when executed / used. In addition, various system programs, such as well-known analysis programs, are written in the ROM 12 in advance.

[0011] The interface 15 is an interface for connecting the CPU 11 of the measuring device 1 to an external device 32 such as a USB device. For example, a control program and various parameters used to control the industrial machine 3 can be read from the external device 32. In addition, the control program and various parameters edited within the measuring device 1 can be stored in an external storage means via the external device 32.

[0012] The display device 30 displays various data loaded into memory, data obtained as a result of executing programs, system programs, etc., output via the interface 18. In addition, the input device 31, which is comprised of a keyboard, pointing device, etc., passes instructions, data, etc. based on operations by an operator to the CPU 11 via the interface 19.

[0013] Measuring instrument 35 is connected to measuring device 1 via interface 20. Measuring instrument 35 may be, for example, a distance detector that emits laser light and detects distance based on the reflected light. It may also be an ultrasonic sensor. Interface 20 converts the signal input from measuring instrument 35 into distance data and passes it to CPU 11.

[0014] The motor 37 is connected to the measuring device 1 via the interface 21. The interface 21 drives the motor 37 based on a control command for the motor 37 input from the CPU 11. The motor 37 has a built-in position and speed detector, and feeds back position and speed feedback signals from this position and speed detector. The position and speed of the motor 37 are then controlled based on the control command and feedback signal.

[0015] 2 is a schematic diagram of gear shape measurement using measuring device 1 according to this embodiment. Measuring device 1 is connected to measuring instrument 35 and motor 37. The gear to be measured is attached to a predetermined rotating shaft. The rotating shaft rotates by power transmitted from motor 37 via a power transmission member such as a pulley or rotating belt. Measuring instrument 35 is placed at a position a predetermined distance d away from the center of rotation of the gear in the circumferential direction, facing the center of rotation of the gear.

[0016] With this arrangement, motor 37 is driven to rotate the gear and the signal from measuring device 35 is analyzed to measure, for example, the distance from measuring device 35 to the tooth tip when the measurement position is at the gear tooth tip, or the distance from measuring device 35 to the tooth bottom when the measurement position is at the gear tooth bottom. Measuring device 35 outputs a signal indicating the measured distance to measuring device 1. Measuring device 1 can calculate the distance from the gear's center of rotation to the measurement position by subtracting the distance measured by measuring device 35 from the distance d between measuring device 35 and the gear's center of rotation, for example.

[0017] 3 is a schematic block diagram showing the functions of the measurement device 1 according to this embodiment. Each function of the measurement device 1 according to this embodiment is realized by the CPU 11 of the measurement device 1 shown in FIG. 1 executing a system program and controlling the operation of each part of the measurement device 1.

[0018] The measurement device 1 of this embodiment includes a coordinate value calculation unit 110, a measurement information recording unit 120, and an incorrect speed determination unit .

[0019] The coordinate value calculation unit 110 calculates the coordinate values ​​of the rising and falling edge positions of the gear teeth based on the signal input from the measuring device 35. For example, the coordinate value calculation unit 110 stores a series of distance data calculated based on the signal input from the measuring device 35 in a predetermined buffer memory prepared in advance. Then, when a predetermined number or more of series of distance data indicating a distance shorter than the previously measured distances continue, the coordinates of the rising edge positions of the gear teeth may be calculated from these series of distance data. Also, when a predetermined number or more of series of distance data indicating a distance longer than the previously measured distances continue, the coordinate value calculation unit 110 may calculate the coordinates of the falling edge positions of the gear teeth from these series of distance data. The coordinate value calculation unit 110 displays the calculated coordinate values ​​on the display device 30.

[0020] FIG. 4 is a graph showing an example of a series of distance data calculated based on a signal input from the measuring device 35. A signal is input from the measuring device 35 to the measuring device 1 at a predetermined cycle. The distance data calculated based on the input signal is stored in a buffer memory. The buffer memory stores a predetermined number of the most recent distance data. At this time, the coordinate value calculation unit 110 monitors the series of distance data stored in the buffer memory. Then, after a series of distance data of a predetermined distance d1 has continued (in FIG. 4, at time t i ~t (i+2) ), the distance changes significantly (in Figure 4, time t (i+3) ~t (i+4) ), followed by a series of distance data indicating a distance d2 that is shorter than the predetermined distance d1 (in FIG. 4, at time t (i+5) ~t (i+7) When such a change trend in the distance is detected, the coordinate value calculation unit 110 calculates the coordinate value of the rising position of the gear tooth based on the position of the motor 37 at any time between the time when the distance d1 was last detected and the time when the distance d2 was first detected. The coordinate value of the rising position can be calculated appropriately based on the position of the motor 37 at that time, the reduction ratio of the power transmission member, etc.

[0021] 5 is a graph showing another example of a series of distance data calculated based on a signal input from the measuring device 35. The coordinate value calculation unit 110 monitors the series of distance data stored in the buffer memory, and calculates the distance data after a series of distance data of a predetermined distance d2 (in FIG. 5, at time t j ~t (j+2) ), the distance changes significantly (in Figure 5, time t (j+3) ~t (j+4) ), followed by a series of distance data indicating a distance d1 that is longer than the predetermined distance d2 (in FIG. 5, at time t (j+5) ~t (j+7) When such a change in distance is detected, the coordinate value calculation unit 110 calculates the coordinate value of the trailing edge position of the gear tooth based on the position of the motor 37 at any time between the time when the distance d2 was last detected and the time when the distance d1 was first detected. The coordinate value of the trailing edge position can be calculated appropriately based on the position of the motor 37 at that time and the reduction ratio of the power transmission member, etc.

[0022] 4 and 5 are merely examples, and other known methods for calculating rising and falling edges may be used as appropriate.

[0023] The coordinate value calculation unit 110 executes the calculation process of the coordinate values ​​of the rising and falling edges, as exemplified above, for the time allocated for each control cycle. If the calculation process of the coordinate value of one rising or falling edge takes longer than a predetermined time, for example, while the rising edge of a gear tooth is detected and the coordinate of the rising edge is being calculated, the next falling edge may pass the measurement position of the measuring device 35. Then, when the coordinate value calculation unit 110 finishes calculating the coordinate of the rising edge, the distance data recording the falling edge position is lost from the buffer memory. In such a case, the coordinate value of the falling edge cannot be calculated correctly. Therefore, the measurement information recording unit 120 and the speed error determination unit 130 detect this situation and notify the user.

[0024] The measurement information recording unit 120 records measurement information relating to the time interval at which a change in the shape of the workpiece occurs. The measurement information may be, for example, the time interval at which a change in the shape of the workpiece occurs, calculated based on a signal input from the measuring device 35. In this case, the measurement information recording unit 120 monitors, for example, the signal input from the measuring device 35, and determines whether the distance calculated based on the signal has changed within a predetermined time t v A predetermined distance d or more within v The measurement information recording unit 120 may be configured to determine that a shape change has been detected when the time at which the shape change has occurred has changed by only a predetermined amount. Then, for example, the measurement information recording unit 120 stores the time at which the shape change has been detected in the RAM 13 or nonvolatile memory 14. Then, the difference between the time at which the shape change has been detected and the time at which the previous shape change has been detected may be recorded as measurement information relating to the time interval at which the shape change occurs. Only the shortest time interval may be recorded as measurement information relating to the time interval at which the shape change occurs. Note that the measurement information recording unit 120 may record the time at which the detected time interval at which the shape change occurs is equal to or shorter than a predetermined time t err If the time interval is less than this, the time interval may not be recorded. By configuring in this way, it becomes possible to deal with cases where a change in the shape of the workpiece is erroneously detected due to disturbances such as chattering.

[0025] The measurement information may be calculated based on the number of times that the shape of the workpiece changes within a predetermined time. In this case, the measurement information recording unit 120 prepares, for example, a counter in the RAM 13 or the nonvolatile memory 14 for recording the number of times that the shape changes. Then, after a predetermined time t from the start of measurement, p The counter is incremented each time a shape change is determined to have occurred during the predetermined time t p The counter value after the predetermined time t p The measurement information recording unit 120 records the value obtained by dividing the time interval at which the shape change occurs as measurement information relating to the time interval at which the shape change occurs. errIf the difference is less than the above, the change in shape may not be counted. By configuring in this way, it becomes possible to deal with cases where a change in the shape of the workpiece is erroneously detected due to disturbances such as chattering.

[0026] Furthermore, the measurement information may be calculated based on the shape specifications of the workpiece and the speed of the motor 37. The measurement information recording unit 120 acquires the speed of the motor 37 directly from the motor 37 or from a command speed for the motor 37. Then, based on the acquired speed of the motor 37, the reduction ratio of the power transmission member, and the shape specifications of the workpiece (for example, in the case of a gear, the tooth root circumference length, tooth tip circumference length, tooth root diameter, tooth tip diameter, number of teeth, tooth pressure, circular pitch, etc.), it calculates the time interval at which a change in the shape of the workpiece occurs, and records the calculated value as measurement information.

[0027] The speed irregularity determination unit 130 determines whether the relative speed between the workpiece and the measuring device is irregular based on the measurement information stored by the measurement information recording unit 120. For example, the speed irregularity determination unit 130 determines whether the time interval at which the shape of the workpiece changes is equal to or shorter than a predetermined threshold value t th If the relative speed between the workpiece and the measuring device is shorter than the predetermined threshold value t th The value of may be calculated in advance by conducting an experiment or the like. p may be set in advance or may be set to a predetermined threshold value c th and the speed of the motor 37. When the speed incorrect determination unit 130 determines that the relative speed between the workpiece and the measuring device is incorrect, it notifies the coordinate value calculation unit 110 that the coordinate values ​​have not been calculated correctly and the measurement object has not been evaluated correctly. Upon receiving the notification, the coordinate value calculation unit 110 displays on the display device 30 the calculated coordinate values ​​as well as a message that the coordinate values ​​have not been calculated correctly and the measurement object has not been evaluated correctly. At this time, an alarm may also be output.

[0028] The measuring device 1 according to this embodiment, which is configured as described above, determines whether the coordinate values ​​of the position where the shape of the measurement surface of the measurement object has changed have been accurately calculated, and if they have not been accurately calculated, notifies the user. The user, upon receiving the notification, can adjust the relative speed between the workpiece and the measuring device and attempt to measure the shape of the workpiece again. As a result, it becomes possible to use the correct measurement results of the workpiece.

[0029] [Second embodiment] A measurement device according to a second embodiment of the present disclosure will be described below with reference to the drawings. The measurement device 1 according to this embodiment has the same hardware configuration as the measurement device according to the first embodiment.

[0030] 6 is a schematic block diagram showing the functions of the measurement device 1 according to this embodiment. Each function of the measurement device 1 according to this embodiment is realized by the CPU 11 of the measurement device 1 shown in FIG. 1 executing a system program and controlling the operation of each part of the measurement device 1.

[0031] The measuring device 1 according to this embodiment further comprises a motor speed calculation unit 140 in addition to a coordinate value calculation unit 110, a measurement information recording unit 120, and an incorrect speed determination unit . The coordinate value calculation unit 110 and the measurement information recording unit 120 according to this embodiment have the same functions as those of the measurement device 1 according to the first embodiment.

[0032] When the speed incorrectness determination unit 130 according to this embodiment determines that the relative speed between the workpiece and the measuring device is incorrect, it instructs the motor speed calculation unit 140 to control the motor speed.

[0033] When the motor speed calculation unit 140 is instructed by the speed error determination unit 130 to control the motor speed, it acquires measurement information relating to the time interval at which a shape change occurs from the measurement information recording unit 120. Then, it calculates the time interval at which a shape change occurs based on a predetermined threshold t thThen, the currently instructed speed of the motor 37 is multiplied by the calculated ratio, and the result is set as the new motor speed. At this time, the motor speed calculation unit 140 subtracts a predetermined margin value v from the calculated motor speed. m The motor speed calculation unit 140 may notify the user of the newly set speed of the motor 37 by displaying it on the display device 30, for example.

[0034] The measuring device 1 according to this embodiment, which is configured as described above, determines whether the coordinate values ​​of the position where the shape of the workpiece has changed have been calculated accurately, and if they have not been calculated accurately, changes the motor speed based on the measurement information so that the coordinate values ​​of the position where the shape of the workpiece has changed can be calculated accurately. As a result, it becomes possible to use the correct measurement results of the workpiece.

[0035] The measuring device 1 according to each embodiment described above determines whether the coordinate values ​​of the position where the shape of the workpiece has changed have been accurately calculated, and if they have not been accurately calculated, notifies the user. The user who receives the notification can adjust the relative speed between the workpiece and the measuring device and attempt to measure the shape of the workpiece again. As a result, it becomes possible to use the correct measurement results of the workpiece.

[0036] The above example shows the measurement of the shape of gear teeth as the measurement target. However, as shown in FIG. 7, the present invention can also be used to measure the surface shape of workpieces other than gears. In the example of FIG. 7, a measuring device 35 is placed on the measurement surface of a workpiece placed on a table. A motor 37 is then driven to move the table, causing the measuring device 35 to scan along the surface of the workpiece. Even in such a case, the measuring device 1 according to the present disclosure can determine whether the table movement speed is incorrect and notify the user. The measuring device 1 according to the present disclosure can also be effectively used when the measuring device 35 is held by a robot or the like and used to scan the measurement surface of the workpiece.

[0037] Although the present disclosure has been described in detail above, 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 spirit of the present disclosure derived from the content of the claims and their equivalents. 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. The same applies when numerical values ​​or mathematical expressions are used in the description of the above-described embodiments.

[0038] The following additional notes are provided regarding the above-described embodiment and modifications. (Appendix 1) The measurement device comprises a coordinate value calculation unit that calculates the coordinate values ​​of the position where the shape of the measurement surface has changed based on a signal input from a measuring instrument that moves the relative position of the measurement surface of the measurement object and measures changes in the shape of the measurement surface; a measurement information recording unit that records measurement information related to the time interval at which a shape change occurs on the measurement surface of the measurement object; and a speed incorrectness determination unit that determines that the relative speed between the measurement surface of the measurement object and the measuring instrument is incorrect if the time interval at which a shape change occurs on the measurement surface of the measurement object recorded by the measurement information recording unit is shorter than a predetermined first threshold value.When the speed incorrectness determination unit determines that the relative speed between the measurement surface of the measurement object and the measuring instrument is incorrect, it notifies that the measurement surface of the measurement object has not been correctly evaluated.

[0039] (Appendix 2) When the time interval during which a shape change occurs on the measurement surface of the measurement object is shorter than a predetermined second threshold, the measurement information recording unit does not record the measurement information relating to the time interval.

[0040] (Appendix 3) The measurement device further includes a motor speed calculation unit that, when the speed irregularity determination unit determines that the relative speed between the measurement surface of the measurement object and the measuring instrument is irregular, calculates the speed of a motor that moves the measurement surface of the measurement object that is not determined to be irregular relative to the measuring instrument based on the measurement information and the first threshold value.

[0041] (Appendix 4) The measurement device changes the speed of the motor to the speed of the motor calculated by the motor speed calculation unit.

[0042] 2. The measurement device according to claim 1, wherein when the speed irregularity determination unit determines that the relative speed between the measurement surface of the measurement object and the measuring device is irregular, it issues an alarm. [Explanation of symbols]

[0043] 1. Measuring equipment 11 CPU 12 ROM 13 RAM 14 Non-volatile memory 15,18,19,20,21 Interface 22 Bus 30 Display device 31 Input Devices 32 External equipment 35 Measuring instruments 37 Motor 110 Coordinate value calculation unit 120 Measurement information recording unit 130 Speed ​​fraud detection section 140 Motor speed calculation unit

Claims

1. a coordinate value calculation unit that calculates coordinate values ​​of a position where the shape of the measurement surface has changed based on a signal input from a measuring instrument that moves a relative position of the measurement surface to the object to measure the change in the shape of the measurement surface; a measurement information recording unit that records measurement information relating to a time interval at which a shape change occurs on the measurement surface of the measurement object; a speed irregularity determination unit that determines that the relative speed between the measurement surface of the measurement object and the measuring device is irregular when the time interval at which a shape change occurs on the measurement surface of the measurement object recorded by the measurement information recording unit is shorter than a predetermined first threshold value; Equipped with When the speed incorrectness determination unit determines that the relative speed between the measurement surface of the measurement object and the measuring device is incorrect, it notifies that the measurement surface of the measurement object has not been correctly evaluated. Measuring device.

2. the measurement information recording unit does not record the measurement information relating to a time interval at which a shape change occurs on the measurement surface of the measurement object when the time interval is shorter than a predetermined second threshold value; The measuring device according to claim 1 .

3. and a motor speed calculation unit that calculates, when the speed irregularity determination unit determines that the relative speed between the measurement surface of the measurement object and the measuring device is irregular, the speed of a motor that moves the measurement surface of the measurement object that is not determined to be irregular and the measuring device relatively, based on the measurement information and the first threshold value. The measuring device according to claim 1 .

4. changing the speed of the motor to the speed of the motor calculated by the motor speed calculation unit; The measuring device according to claim 3 .

5. When the speed irregularity determination unit determines that the relative speed between the measurement surface of the measurement object and the measuring device is irregular, it issues an alarm. The measuring device according to claim 1 .

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