Position measurement control device and position measurement method

Abstract

a first start position acquisition unit that acquires a first start position, which is the position of the contact body when a manual operation to bring the contact body into contact with the measurement object is started; a measurement position acquisition unit that acquires a measurement position, which is the position of the contact body in a state where the contact body is in contact with the measurement object; a separation instruction unit that instructs a user to move the contact body away from the measurement object by manually operating a drive mechanism when it is determined that the first start position and the measurement position match; a position change acquisition unit that acquires a position change of the contact body during the manual operation to move the contact body away from the measurement object; a contact direction determination unit that determines the contact direction of the contact body relative to the measurement object at the measurement position based on the first start position or the position change and the measurement position; and a position calculation unit that calculates the contact position of the contact body and the measurement object based on the measurement position and the contact direction.

Description

[Technical Field]

[0001] The present disclosure relates to a position measurement control device and a position measurement method. [Background technology]

[0002] In machine tools and the like, a contact body is held by a drive mechanism and manually brought into contact with an object to be measured, thereby calculating the position of the object. An expensive probe capable of detecting the contact direction may be used as the contact body, but an inexpensive metal rod or the like that does not include a sensor may also be used. Because the contact body has a certain size, there is a deviation between the reference position of the contact body and the position where it is in contact with the object to be measured. Therefore, it is desirable to determine the direction of the contact body where the object to be measured is in contact, correct the deviation between the reference position of the contact body and the position where it is in contact with the object to calculate the accurate position of the object to be measured.

[0003] A technology has also been proposed that determines the direction in which the contact body contacts the object to be measured based on the position of the contact body at the start of the operation of bringing the contact body into contact with the object to be measured and the position of the contact body in contact with the object to be measured, and corrects the error equivalent to the radius of the contact body to calculate the accurate position of the object to be measured (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2023 / 228356 Summary of the Invention [Problem to be solved by the invention]

[0005] In a method for acquiring the position of the contact body at the start of its movement and the position where it contacts the measurement object, the user must prepare to attach the contact body to the drive mechanism, and then perform a confirmation operation by operating a switch or the like before starting the movement of the contact body and after manually operating the drive mechanism to bring the contact body into contact with the measurement object, thereby allowing the numerical control device to acquire the position of the contact body. However, if the user forgets to perform the confirmation operation after attaching the contact body and performs the confirmation operation twice after bringing the contact body into contact with the measurement object, the position of the contact body at the start of its movement and the position where it contacts the measurement object may be detected as the same position. If the position of the contact body at the start of its movement and the position where it contacts the measurement object are the same position, it is impossible to determine the direction in which the contact body contacts the measurement object. Therefore, a technology that can reliably determine the contact direction of the contact body relative to the measurement object is desired. [Means for solving the problem]

[0006] A position measurement control device according to one aspect of the present disclosure is a position measurement control device that brings a contact body into contact with a measurement object by a user manually operating a drive mechanism that positions the contact body relative to the measurement object, and calculates a contact position between the contact body and the measurement object based on a change in position of the contact body identified by drive information of the drive mechanism, the position measurement control device including: a first start position acquisition unit that acquires a first start position, which is the position of the contact body when the manual operation to bring the contact body into contact with the measurement object is started; and a measurement position acquisition unit that acquires a measurement position, which is the position of the contact body in a state where the contact body is in contact with the measurement object. The device is equipped with a separation instruction unit that instructs the user to move the contact body away from the measurement object by manually operating the drive mechanism when it is determined that the first start position and the measurement position match; a position change acquisition unit that acquires a position change of the contact body during the manual operation of moving the contact body away from the measurement object; a contact direction determination unit that determines the contact direction of the contact body with respect to the measurement object at the measurement position based on the first start position or the position change and the measurement position; and a position calculation unit that calculates the contact position of the contact body and the measurement object based on the measurement position and the contact direction. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a schematic diagram showing the configuration of a machine tool equipped with a position measurement control device according to a first embodiment of the present disclosure. [Figure 2] 2 is a schematic diagram illustrating position measurement by the position measurement control device of FIG. 1. FIG. [Figure 3] 3 is a flowchart showing the procedure of a position measurement method using the position measurement control device of FIG. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. FIG. 1 is a schematic diagram showing the configuration of a machine tool 1 equipped with a position measurement control device 20 according to a first embodiment of the disclosure. The machine tool 1 machines a workpiece W (measurement object) by positioning a tool (not shown) relative to the workpiece W. The machine tool 1 also functions as a position measurement device system that accurately identifies the position of the measurement object W by positioning a contact body C and bringing it into contact with the measurement object W. The machine tool 1 includes a drive mechanism 10 that positions the tool or contact body C relative to the measurement object W, and a position measurement control device 20 that controls the drive mechanism 10.

[0009] The drive mechanism 10 may be configured to include a head H that holds the contact body C, a table B that holds the measurement target W, and multiple drive axes Ax, Ay, and Az that move the head H. The drive mechanism 10 may also be used as a mechanism that moves a tool to machine the workpiece W. In other words, the head H that holds the contact body C is typically provided on a spindle that can hold and rotate the tool. Note that the drive mechanism 10 is not limited to the Cartesian coordinate drive mechanism shown in the figure, but may also be a vertical articulated drive mechanism, a SCARA drive mechanism, a parallel link drive mechanism, or the like, and the number of drive axes may also be changed as desired.

[0010] The position measurement control device 20 brings the contact body C into contact with the measurement object W through manual operation by a user of the drive mechanism 10, and calculates the contact position between the contact body C and the measurement object W, and ultimately the position of the measurement object W, based on the change in the position of the contact body C identified by the drive information of the drive mechanism 10. The position measurement control device 20 may be realized by one or more computers having, for example, a processor, memory, an input / output interface, etc., and executing appropriate control programs. The position measurement control device 20 may be integrated with a numerical control device that controls the machine tool 1. Furthermore, the position measurement control device 20 may have output devices such as a display and a speaker, and input devices such as switches, levers, and rotary handles, to facilitate user operation. Furthermore, these output devices and input devices may be provided on a control panel or the like provided separately from the position measurement control device 20.

[0011] The position measurement control device 20 includes a manual operation unit 21, a first start position acquisition unit 22, a measurement position acquisition unit 23, a separation instruction unit 24, a position change acquisition unit 25, a contact direction determination unit 26, and a contact position calculation unit 27. Note that these components categorize the functions of the position measurement control device 20, and do not necessarily have to be clearly distinguishable in terms of physical configuration and program configuration.

[0012] The manual operation unit 21 generates a command to drive the drive axes Ax, Ay, Az in accordance with the user's operation, thereby generating a drive command to displace the drive axes Ax, Ay, Az by an amount corresponding to the user's operation. As a specific example, the manual operation unit 21 may be configured to displace the drive axes Ax, Ay, Az at a constant speed only while a switch or the like is being operated, or may be configured to displace the drive axes Ax, Ay, Az at a speed corresponding to the amount of operation of a lever or the like, or may be configured to displace the drive axes Ax, Ay, Az by an amount proportional to the amount of operation of a rotary handle.

[0013] The first start position acquisition unit 22 acquires a first start position, which is the position of the contact body C when a manual operation to bring the contact body C into contact with the measurement object W is started. The first start position acquisition unit may determine, as the first start position, the position of the contact body C when a predetermined operation is performed by the user, such as a predetermined button operation indicating the start of the operation of the contact body C. The first start position acquisition unit 22 may also determine, as the first start position, the position of the contact body C when a predetermined change occurs in a signal, screen display, or the like. The signal may be a button operation or a signal obtained from a measuring device such as a probe. The predetermined change in the screen display, or the like, may be the display of a measurement screen, a measurement in progress mode display, or the like. Typically, the position of the contact body C is determined to be the center position of the contact portion of the contact body C with respect to the measurement object W. Therefore, in the following description, the position of the contact body C will be described as the center position of the contact portion.

[0014] The measurement position acquisition unit 23 acquires a measurement position, which is the position of the contact body C in a state where the contact body C is in contact with the measurement object W. The measurement position acquisition unit 23 may take the position of the contact body C when a predetermined operation is performed by the user, such as a predetermined button operation indicating the completion of contact of the contact body C with the measurement object W, as the measurement position.

[0015] When it is determined that the first start position and the measurement position match, the separation instructing unit 24 instructs the user to separate the contact body C from the measurement object W by manually operating the drive mechanism 10. The separation instructing unit 24 may be configured to determine that the first start position and the measurement position match when the distance between the first start position and the measurement position is equal to or less than a predetermined determination threshold. The separation instructing unit 24 may be configured to instruct the user to separate the contact body C from the measurement object W by outputting a message on a display, a voice from a speaker, a buzzer sound, or the like.

[0016] The position change acquisition unit 25 acquires a position change of the contact body C during a manual operation to separate the contact body C from the measurement object W. When the separation instruction unit 24 instructs the user to separate the contact body C, the position change acquisition unit 25 can be configured to acquire the coordinate position of the contact body C thereafter or the positions of the drive axes Ax, Ay, Az that position the contact body C for each control cycle.

[0017] The contact direction determination unit 26 determines the contact direction of the contact body C relative to the measurement object W at the measurement position based on the position change of the contact body C for separating it from the measurement object W and the measurement position when the separation instruction unit 24 instructs the user to separate the contact body C from the measurement object W, and based on the first start position and the measurement position when the separation instruction unit 24 does not instruct the user to separate the contact body C from the measurement object W.

[0018] 2, the contact direction determination unit 26 may be configured to determine that the contact direction Df of the contact body C with respect to the measurement object W is the direction opposite to the separation direction Dr, which is the moving direction when the user separates the contact body C from the measurement object W. Furthermore, when the separation instruction unit 24 does not instruct the contact body C to separate from the measurement object W, the contact direction determination unit 26 may be configured to determine that the contact direction Df is the direction from the first start position Pa toward the measurement position Po.

[0019] The contact direction determination unit 26 may be configured to identify a position of the contact body C different from the first start position during the manual operation of separating the contact body C from the measurement object W, i.e., a second start position Pb which is the position of the contact body C separated from the measurement object W. In this case, the contact direction determination unit 26 may be configured to determine the contact direction Df of the contact body C with respect to the measurement object W, assuming that the contact body C has come into contact with the measurement object W by moving from the second start position Pb to the measurement position Po. This makes it possible to appropriately determine the contact direction Df even when the contact direction Df of the contact body C with respect to the measurement object W is different from the drive axes Ax, Ay, Az and the user operates multiple axes among the multiple drive axes Ax, Ay, Az in order.

[0020] Furthermore, the contact direction determination unit 26 may be configured to determine, as the second start position Pb, the position at which the distance L of the contact body C from the measurement position Po is at a maximum or longest point in the positional change of the contact body C. Specifically, the contact direction determination unit 26 may be configured to determine, as the second start position Pb, the position at which the movement direction of the contact body C is reversed. Movement of the contact body C by manual operation may have multiple maximum points of the distance L from the measurement position Po, but it is possible to identify the contact direction Df of the contact body C with respect to the measurement target W by using any of the maximum points as the second start position Pb. However, since the contact direction Df can be more reliably identified as the distance L of the second start position Pb from the measurement position Po is greater, it is preferable to determine the position at which the distance L from the measurement position Po is at a maximum as the second start position Pb. As an example, the contact direction determination unit 26 can be configured to store the maximum value of the distance L from the measurement position and the position of the contact body C at that time, calculate the distance L from the measurement position of the position of the contact body C for each control cycle, and if the newly calculated distance L is greater than the previously stored distance L, repeat the process of overwriting the new distance L and position.

[0021] The contact position calculation unit 27 calculates the contact position Pw between the contact body C and the measurement object W based on the measurement position Po and the contact direction Df. The position Pw where the contact body C and the measurement object W are actually in contact is a position offset by the radial distance R of the contact body C in the contact direction Df of the contact body C relative to the measurement object W, with the measurement position (center position) Po of the contact body C as the reference. Therefore, the coordinates of the position Pw where the contact body C and the measurement object W are actually in contact can be accurately calculated based on the measurement position Po and the contact direction Df of the contact body C relative to the measurement object W.

[0022] A position measurement method according to one embodiment of the present disclosure, which is performed using the above-described machine tool, includes, as shown in FIG. 3, a step of acquiring a first start position Pa, which is the position of the contact body C when the manual operation is started (step S1); a step of acquiring a measurement position Po, which is the position of the contact body C when the contact body C is in contact with the measurement object W (step S2); a step of determining whether the first start position Pa and the measurement position Po coincide (step S4); a step of separating the contact body C from the measurement object W when it is determined that the first start position Pa and the measurement position Po coincide (step S4); a step of acquiring a position change of the contact body C during the manual operation of separating the contact body C from the measurement object W (step S5); a step of determining a contact direction Df of the contact body C with respect to the measurement object W at the measurement position Po based on the first start position Pa or the position change and the measurement position Po (step S6); and a step of calculating a contact position Pw of the contact body C and the measurement object W based on the measurement position Po and the contact direction Df (step S7).

[0023] As described above, in the position measurement method according to this embodiment, when it is determined that the first start position and the measurement position are the same, the contact body C is moved away from the measurement object W, and the contact direction of the contact body C relative to the measurement object W is determined based on the change in the position of the contact body C when it is moved away, so that the radius R of the contact body C can be corrected to calculate the accurate contact position Pw between the contact body C and the measurement object W.

[0024] The following additional notes are provided regarding the above-described embodiment and modifications. (Appendix 1) The position measurement control device (20) brings the contact body (C) into contact with the measurement object (W) by manual operation by a user of a drive mechanism (10) that positions the contact body (C) relative to the measurement object (W), and calculates the contact position of the contact body (C) and the measurement object (W) based on a change in the position of the contact body (C) identified by drive information of the drive mechanism (10). The position measurement control device (20) includes a first start position acquisition unit (22) that acquires a first start position (Pa) that is the position of the contact body (C) when the manual operation to bring the contact body (C) into contact with the measurement object (W) is started, a measurement position acquisition unit (23) that acquires a measurement position (Po) that is the position of the contact body (C) in a state where the contact body (C) is in contact with the measurement object (W), and a first The device is provided with a separation instruction unit (24) that instructs a user to separate the contact body (C) from the measurement object (W) by manually operating the drive mechanism (10) when it is determined that the start position (Pa) and the measurement position (Po) match, a position change acquisition unit (25) that acquires a position change of the contact body (C) during the manual operation of separating the contact body (C) from the measurement object (W), a contact direction determination unit (26) that determines the contact direction (Df) of the contact body (C) with respect to the measurement object (W) at the measurement position (Po) based on the first start position (Pa) or the position change and the measurement position (Po), and a position calculation unit (27) that calculates the contact position of the contact body (C) and the measurement object (W) based on the measurement position (Po) and the contact direction (Df).

[0025] (Appendix 2) In the position measurement control device (20) of Appendix 1, the contact direction determination unit (26) may identify a second start position (Pb) that is different from the first start position (Pa) of the contact body (C) during a manual operation to move the contact body (C) away from the measurement object (W).

[0026] (Appendix 3) In the position measurement control device (20) of Appendix 2, the contact direction determination unit (26) may determine, as the second start position (Pb), a position where the moving direction of the contact body (C) is reversed during a position change, or a position where the distance of the contact body (C) from the measurement position (Po) is the greatest.

[0027] (Appendix 4) In the position measurement control device (20) of Supplementary Notes 1 to 3, the separation instruction unit (24) may determine that the first start position (Pa) and the measurement position (Po) match when the distance between the first start position and the measurement position (Po) is equal to or less than a predetermined determination threshold.

[0028] (Appendix 5) In the position measurement control device (20) of Supplementary Notes 1 to 4, the first start position acquisition unit (22) may determine the position of the contact body (C) when the user performs an operation as the first start position (Pa).

[0029] (Appendix 6) In the position measurement control device (20) of Supplementary Notes 1 to 4, the first start position acquisition unit (22) may determine the position of the contact body (C) when a predetermined change occurs in the signal or screen display as the first start position (Pa).

[0030] (Appendix 7) The position measurement method is a position measurement method in which a contact body (C) is brought into contact with a measurement object (W) by manually operating a drive mechanism (10) that positions the contact body (C) relative to the measurement object (W), and a contact position between the contact body (C) and the measurement object (W) is calculated based on a change in the position of the contact body (C) identified by drive information of the drive mechanism (10), the position measurement method comprising the steps of: acquiring a first start position (Pa) which is the position of the contact body (C) when the manual operation is started; acquiring a measurement position (Po) which is the position of the contact body (C) in a state in which the contact body (C) is in contact with the measurement object (W); The method includes the steps of: moving the contact body (C) away from the measurement object (W) when it is determined that the start position (Pa) and the measurement position (Po) are the same; acquiring a position change of the contact body (C) during the manual operation of moving the contact body (C) away from the measurement object (W); determining a contact direction (Df) of the contact body (C) relative to the measurement object (W) at the measurement position (Po) based on the first start position (Pa) or the position change and the measurement position (Po); and calculating a contact position of the contact body (C) and the measurement object (W) based on the measurement position (Po) and the contact direction (Df).

[0031] 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 to these embodiments without departing from the gist of the present disclosure or the spirit of the present disclosure derived from the claims and their equivalents. These embodiments can also be implemented in combination. For example, the order of each operation and each process in the above-described embodiments is shown as an example and is not limited to these. The same applies when numerical values ​​or mathematical formulas are used in the description of the above-described embodiments. For example, the position measurement control device according to the present disclosure may control a position measurement system other than a machine tool, such as a robot handling device. [Explanation of symbols]

[0032] 1 Machine tools 10 Drive mechanism 20 Position measurement control device 21 Manual operation section 22 First starting position acquisition section 23 Measurement position acquisition unit 24 Separation indicator 25 Position change acquisition unit 26 Contact direction determination section 27 Contact position calculation section Ax, Ay, Az drive shaft Table B C Contact body Df contact direction Dr separation direction H Head L distance Pa 1st starting position Pb 2nd starting position Po measurement position R radius W Measurement target

Claims

1. a position measurement control device that brings a contact body into contact with a measurement object by a user manually operating a drive mechanism that positions the contact body relative to the measurement object, and calculates a contact position between the contact body and the measurement object based on a change in position of the contact body identified by drive information of the drive mechanism, a first start position acquisition unit that acquires a first start position, which is a position of the contact body when the manual operation for bringing the contact body into contact with the measurement object is started; a measurement position acquisition unit that acquires a measurement position, which is a position of the contact body in a state where the contact body is in contact with the measurement object; a separation instruction unit that instructs the user to separate the contact body from the measurement object by manually operating the drive mechanism when it is determined that the first start position and the measurement position match; a position change acquisition unit that acquires a position change of the contact body during a manual operation of separating the contact body from the measurement object; a contact direction determination unit that determines a contact direction of the contact body with respect to the measurement object at the measurement position based on the first start position or the position change and the measurement position; a position calculation unit that calculates a contact position between the contact body and the measurement object based on the position change and the measurement position when the separation instruction unit instructs the user to separate the contact body from the measurement object, and based on the first start position and the measurement position when the separation instruction unit does not instruct the user to separate the contact body from the measurement object; A position measurement control device comprising:

2. The position measurement control device according to claim 1 , wherein the contact direction determination unit identifies a second start position of the contact body that is different from the first start position during a manual operation of separating the contact body from the measurement object.

3. 3. The position measurement control device according to claim 2, wherein the contact direction determination unit determines, as the second start position, a position where the movement direction of the contact body is reversed or a position where the distance of the contact body from the measurement position is greatest during the position change.

4. 4. The position measurement control device according to claim 1, wherein the separation instruction unit determines that the first start position and the measurement position are the same when the distance between the first start position and the measurement position is equal to or less than a predetermined determination threshold.

5. The position measurement control device according to claim 1 , wherein the first start position acquisition unit determines the position of the contact body when the user performs the operation as the first start position.

6. The position measurement control device according to claim 1 , wherein the first start position acquisition unit determines the position of the contact body when a signal or a screen display undergoes a predetermined change as the first start position.

7. A position measurement method comprising: bringing a contact body into contact with a measurement object by manually operating a drive mechanism that positions the contact body relative to the measurement object; and calculating a contact position between the contact body and the measurement object based on a change in position of the contact body identified by drive information of the drive mechanism, acquiring a first start position, which is a position of the contact body when the manual operation is started; acquiring a measurement position, which is a position of the contact body in a state where the contact body is in contact with the measurement object; a step of moving the contact body away from the measurement object when it is determined that the first start position and the measurement position match; acquiring a position change of the contact body during a manual operation of separating the contact body from the measurement object; determining a contact direction of the contact body relative to the measurement object at the measurement position based on the first start position or the position change and the measurement position; calculating a contact position between the contact body and the measurement object based on the position change and the measurement position when it is determined that the first start position and the measurement position match and the contact body is moved away from the measurement object, and calculating a contact position between the contact body and the measurement object based on the position change and the measurement position when it is determined that the first start position and the measurement position match and the contact body is not moved away from the measurement object; A position measurement method comprising:

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