JPH0379645B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a measuring method and a measuring device for measuring, for example, a hole diameter of a workpiece from a moving position of a detection means in contact with the workpiece. Conventionally, when adding an automatic measurement function to a machining center, if a contact type detector was used as a detector, the contact signal generated when the detector came into contact with a workpiece to be measured would cause the sensor to be attached to the machine. It is necessary to read the values of the coordinate scale, such as inductosin and resolver. This contact signal is generated while the machine is moving, so if there is a delay in the signal transmission system (such as a delay in electrical signals or a delay in recognition when the contact signal is taken into the arithmetic processing unit), the machine may have gone too far. The coordinates of will be read.
This error increases as the machine feed speed increases. For this reason, in order to perform highly accurate measurements, it is sufficient to make the machine feed speed as slow as possible, but if the machine feed speed is slowed down,
The problem arises that measurement takes too much time and is not practical. On the other hand, in the case of a measurement method that involves contact between the workpiece and the detector, there is a problem in that large measurement errors occur if foreign matter such as chips is attached to the measurement position of the workpiece. Therefore, in order to prevent such problems, foreign matter adhering to the workpiece should be removed before measurement, but this is a difficult task in practice, especially when automatic measurement is performed on a processing machine. An object of the present invention is to provide a measuring method and a measuring device that can eliminate measurement errors caused by foreign objects as described above, and can also improve measurement efficiency while maintaining measurement accuracy. The measurement method of the present invention includes: a detection means that generates a detection signal as it approaches and separates from an object to be measured; a drive means that moves the detection means and the object relative to each other; command means for outputting command value data for commanding relative movement with an object; position detection means for detecting a relative position between the detection means and the object to be measured and outputting the relative position data; and driving based on the detection signal. In a measurement method that performs measurement using a measuring device that is equipped with a control means that controls the means and measures the contact and separation positions of the object to be measured and the detection means, the drive means moves the object to be measured and the detection means relative to each other. The difference between the command value data and the relative position data when the sensor is moved and receives a detection signal due to contact from the sensing means is stored, and the sensing means is relatively moved in the same direction by the difference and then stopped. The detection means is stopped when the object is in contact with the object to be measured by the difference between the command value data and the relative position data (servo error amount), and then the detection means and the object to be measured are moved in the opposite direction until the servo error amount is reached. After relatively moving, the detection signal is determined,
In other words, if there is a foreign object between the detection means and the object to be measured, it will fall off due to relative movement in the opposite direction, so the state at that time is determined, and the detection signal is a signal associated with contact, that is, a state in which there was no foreign object originally. When the detection signal is a signal associated with detachment, that is, when a foreign object is present but has been removed, the detection signal and the object to be measured are moved relative to each other in the direction in which they are in contact with each other. , measurement errors caused by foreign objects are eliminated, and the contact position between the sensing means and the object to be measured is detected during this relative movement based on the detection signal from the sensing means, thereby performing highly accurate measurement without the influence of foreign objects. In addition, by dividing each process of these relative movements, it is possible to make only the detection process slow and the others high speed, aiming to improve measurement efficiency while maintaining measurement accuracy. . Further, the measuring device of the present invention includes a detection means that generates a detection signal upon contact with and separation from an object to be measured, a drive means that relatively moves the detection means and the object to be measured, and a drive means that moves the detection means and the object relative to each other. a command means for outputting command value data related to movement; a position detection means for detecting a relative position between the detection means and the object to be measured and outputting the relative position data; A control means for measuring a contact position between the object to be measured and the detection means is provided.
The control means includes a contact state indicating means that outputs a contact state signal when receiving a detection signal associated with the contact, and a difference between the command value data and the relative position data when receiving the contact state signal. braking distance storage means for storing a braking distance as a braking distance; and a means for relatively moving the object to be measured and the detecting means in a proximal direction at a first speed, and relatively moving the object by the braking distance in the same direction when receiving the contact state signal. a second movement command means that is activated subsequent to the first movement command means and relatively moves the object to be measured and the detection means in opposite directions at a second speed by the braking distance; measurement direction determining means that is activated subsequent to the second movement command means and specifies the opposite direction if the detection signal is in a contact state, and specifies the approaching direction if the detection signal is in a detached state; a third movement command means that is activated subsequent to the determination means and relatively moves the object to be measured and the detection means in a specified direction at a third speed lower than the first speed and the second speed; 3. Measured position output means that is activated together with the movement command means and outputs the relative position data as a measured position when the detection signal changes to either contact or separation. With such a configuration, the object to be measured and the detection signal are first approached at a first speed, and after making contact, they travel a predetermined distance in the same direction, and are returned a predetermined distance in the opposite direction at a second speed. Then, the measurement direction is selected depending on the contact state at this point, and if it is in contact, it is in the opposite direction, that is, in the direction of separation, and if it is separated, it is in the approaching direction, that is, in the direction of contacting again. During this movement, the contact position is measured at the time of separation or contact again. In other words, accuracy is ensured by setting the third speed at a low speed when performing position measurements, and the distance traveled at the third speed is limited to short sections, increasing the moving speed in other sections to speed up the overall process. The purpose of the present invention is to achieve the above-mentioned object by realizing a flexible operation and automatically avoiding the influence of the presence or absence of a foreign object. An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows the entire system of this embodiment. The system uses a piezoelectric element as a detection means mounted on a machining center, for example, in the measurement direction of the workpiece W as the object to be measured, that is, in the diameter direction of the hole H (hereinafter referred to as the x direction) in this embodiment. A contact detector 1 consisting of a contact detector 1, etc., can be moved back and forth by the operation of a drive device 2. The detector 1 includes a probe 1A whose tip is in contact with the workpiece W.
While the probe 1A is in contact with the workpiece W, a detection signal is provided through the signal detection circuit 3 to a control section 4 serving as a control means, which is a main part of the present invention. The control unit 4 provides various control signals to the NC device 5 according to preset processing procedures based on the detection signal provided through the signal detection circuit 3, and also provides various control signals to the NC device 5 under predetermined conditions. It is designed to import the data that has been entered. The NC device 5 also serves as a commanding means and first to third movement commanding means, and is connected to a driving device 2 which indicates the movement position of the detector 1.
The driving device 2 is driven based on the _difference between the measured value data (Position Feedback Signal, hereinafter referred to as PFS) from the position detection device 6 attached to the The drive is controlled according to the following. FIG. 2 shows the circuit configuration of the control section 4 and the NC device 5. The NC device 5 includes an NC device main section 51 that performs predetermined calculations, first and second storage means 52 and 53, an addition section 54, and a difference register 55.
and are included. The main part of the NC device 51 includes:
It includes a sequence section 51A that handles sequence information, a decode section 51B that decodes data from the tape reading section 7, and an interpolation calculation section 51C that outputs a movement command value (Δx/ΔT) at fixed time intervals according to a clock time ΔT. ing. In addition, the first
The storage means 52 is constituted by a feedback counter that sequentially stores the measured value data PFS sequentially inputted from the position detecting device 6. Further, the second moving means 53 includes the main part 51 of the NC device.
A command value counter integrates the movement command values Δx/ΔT sent from the interpolation calculation unit 51A at fixed time intervals and stores the current command value data as X _T =Σ _T (Δx/ΔT). It is configured. The difference between these first and second storage means 52, 53 is given to the difference register 55 via the adder 54 as a so-called servo error SVE. This servo error SVE is given to the drive device 2 including the D/A converter. Incidentally, the addition section 54 and the difference register 55 can be configured as reversible counters. The control section 4 is configured such that the detection signal from the signal detection circuit 3 is input to AND circuits 21 and 22, respectively, and also inputs the detection signal from the signal detection circuit 3 to an inverter 23.
The signal is inputted to the AND circuit 24 via. In addition to the detection signal, the AND circuit 21 receives a clock signal output from the timer circuit 25 at fixed time intervals Δt and a signal from the set output terminal Q of the flip-flop 26. Further, the output from the AND circuit 21 resets the flip-flop Z26 and sends the command value Δx/ to the NC device main section 51.
It is input as a stop command signal STP for stopping the distribution of ΔT and fixing the command value data X _T , and is also given to the gate circuit 27. Here, the AND circuit 21 and the flip-flop 26 constitute contact state indicating means, and the H output of the AND circuit 21 becomes the contact state signal. The gate circuit 27 is opened when the output of the AND circuit 21 becomes H level (logical value 1),
The servo error SVE of the difference register 55 is taken into the third storage means 28 which is a braking distance storage means. The data taken into the third storage means 28 is stored as the braking distance ΔX _SVE for moving the detector 1 in the opposite direction when the difference register 55 is once set to zero. given to. In addition to the signal from the signal detection circuit 3, the AND circuits 22 and 24 also receive a discrimination command signal HS outputted from the NC device main section 51 after the operation based on the signal ΔX _SVE is completed. There is.
The set input terminals S of flip-flops 29 and 30 are connected to the output terminals of the AND circuits 22 and 24, respectively. A signal from the set output terminal Q of one flip-flop 29 is inputted to the NC device main section 51 as a forward feed command signal FS for driving the drive device 2 in the direction in which the detector 1 moves away from the workpiece W. and is also applied to the AND circuit 31. Also, the set output terminal Q of the other flip-flop 30
The signal from the AND circuit 33 is outputted to the NC device main section 51 as a reverse feed command signal RS for driving the drive device 2 in the direction in which the detector 1 contacts the workpiece W. is given to. Here, the AND circuits 22, 24 and the flip-flops 29, 30 constitute a measurement direction determining means, and the measurement direction is designated by the forward feed command signal FS or the reverse feed command signal RS. On the other hand, the AND circuit 31 receives a sequential feed command signal.
In addition to the FS, a signal obtained by inverting the detection signal from the signal detection circuit 3 by an inverter 32 and a clock signal from the timer circuit 25 are input. In addition to the reverse feed command signal RS, the AND circuit 33 also receives a detection signal from the signal detection circuit 3,
and a clock signal from the timer circuit 25 are respectively input. Outputs from these AND circuits 31 and 33 are given to a gate circuit 35 through an OR circuit 34. The gate circuit 35 includes the AND circuit 31,
33 is released when the output of one of them becomes H level, and the data of the first storage means 52 is stored in the fourth memory means 52.
The data is taken into the storage means 36 of. Here, the AND circuits 31, 33 and the fourth storage means 36 constitute a measured position output means, and the data taken into the fourth storage means 36 is outputted as a measurement value to, for example, a display.
The flip-flop 26 is set to the set state by an initial setting command signal SS from the sequence section 51A of the main part of the NC device. Further, the flip-flops 29 and 30 have an OR circuit 37
The command signal SS from the sequence section 51A of the NC device main section 51 and the output from the OR circuit 34 are respectively reset. Next, the operation of this embodiment will be explained with reference to FIGS. 3, 4, and 5. First, the sequence section 51A of the NC device main section 51
The flip-flop 26 is placed in the set state by the initial setting command signal SS from the flip-flop 2.
9 and 30 are respectively initialized to the reset state, the detector 1 is moved from the reference position P ₀ , which is the measurement starting point, to the high-speed first speed V ₁ via the drive device 2 in response to a command from the NC device main section 51. When it is moved (see FIG. 3), a position feedback signal PFS is sequentially given from the position detection device 6 attached to the drive device 2, and the measured data is stored in the first storage means 52. On the other hand, in the process of the detector 1 moving at a speed V ₁ , when the probe 1A reaches the position P where it contacts the workpiece W, an H level detection signal (contact signal) is transmitted through the signal detection circuit 3 to the AND circuit of the control unit 4. 21
given to. At this time, if a foreign object such as chips is attached to the surface to be measured of the workpiece W, the probe 1A is at a position P' where it comes into contact with the foreign object, that is, the workpiece W.
H at the point before the position in contact with the true surface to be measured.
A level detection signal is given to the AND circuit 21. Since the flip-flop 26 is in the set state, that is, the AND circuit 21 is in a state where an H level signal is applied from its set output terminal Q, when the clock signal from the timer circuit 25 is applied, the AND circuit 21 outputs an H level signal. occurs. Then,
The flip-flop 26 is reset by the H level output from the AND circuit 21, and at the same time, a stop command signal is sent to the main part of the NC device 51.
STP is given. As a result, the main part of the NC device 5
1 stops the distribution of the command value Δx/ΔT from the interpolation calculation unit 51C to the second storage means 53, and fixes the command value data X _T in the second storage means 53. Further, the H level output from the AND circuit 21 opens the gate circuit 27. Then, the difference (servo error amount SVE) between the measured value data of the first storage means 52 and the command value data of the second storage means 53, that is, the value of the difference register 55, is stored as the braking distance ΔX _SVE in the third storage means. 28. Thereafter, the detector 1 is moved to a position P ₁ or P ₁ ' where the servo error amount becomes zero and is stopped (see FIG. 3). Here, the overshoot amount l of the detector 1 from when the probe 1A of the detector 1 comes into contact with the workpiece W and the corresponding detection signal is output until it stops is: l=servo error amount +V ₁ · Δt ₁ ... ...(1) Here, V ₁ ∆t ₁ is the amount of deviation in the stop position due to the delay error ∆t ₁ that occurs during braking, and ∆t 1 is the amount of deviation of the stop position due to the delay error ∆t 1 that occurs during braking, and ∆t ₁ is the detection signal when the probe 1A of the detector 1 is in contact with the workpiece W. This is the time from when the clock signal is output to when the clock signal is applied to the timer circuit 25, that is, the delay until the control section 4 recognizes the detection signal, and is smaller than at least the cycle Δt of the clock signal. Next, the position P ₁ where the detector 1 stopped, or
From P ₁ ', the detector 1 is moved in the opposite direction by the braking distance ΔX _SVE of the third storage means 28 at a relatively high second speed V ₂ . When this movement stops, the NC
A discrimination command signal HS is given from the main part 51 of the apparatus to the AND circuits 22 and 24 of the control part 4. Here, the AND circuits 22 and 24 determine whether the detection signal provided through the signal detection circuit 3 is at H level or L level. Normally, when the probe 1A first outputs a contact signal, if there is no foreign object between the workpiece W and the probe 1A, the controller 4 is activated after the probe 1A actually contacts the workpiece W. Since there is a time delay until contact is recognized, the H level detection signal, that is, probe 1
A is in contact with the workpiece W, but if a foreign object is interposed between the workpiece W and the probe 1A, when the probe 1A comes into contact with the foreign object, the foreign object Since the probe 1A falls off, the detection signal is at L level, that is, the probe 1A is separated from the workpiece W. Now, assuming that there was no foreign object when the probe 1A first outputs the contact signal, the H level detection signal is being given to the AND circuits 22 and 24, so the AND circuit 22 outputs an H level signal. be done. Then flipflop 2
9 is set, so the flip-flop 2
An H level signal from the set output terminal Q of No. 9 is applied to the AND circuit 31, and is also applied to the main section of the NC device 51 as a forward feed command signal FS. As a result, the NC device main part 51 detects the detector 1 in the previous step.
The position where is moved in the opposite direction by the servo error amount
From P ₂ , the detector 1 is moved in the same direction at a third speed V ₃ that is low or very small. In the process of detector 1 moving at speed V ₃ ,
Position P where the probe 1A leaves the workpiece W
When the detection signal reaches the inverter 3 of the control unit 4, an L level detection signal (disengagement signal) is transmitted through the signal detection circuit 3.
After being inverted in step 2, it is applied to the AND circuit 31. Since the flip-flop 29 is in the set state, that is, the AND circuit 31 is in the state where an H level signal is applied from the set output terminal Q, when the clock signal from the timer circuit 25 is applied, the AND circuit 31 outputs an H level output. Occur. Then, the gate circuit 35 is opened by the H level output from the AND circuit 31, and the measured value data of the first storage means 52 at this time is stored in the fourth storage means 36, and at the same time, the flip-flop 29 is reset to its initial state. Thereafter, the data stored in the fourth storage means 36 can be displayed as measured values on, for example, a display. Here, from the time when the probe 1A of the detector 1 detaches from the workpiece W and the detection signal at that time is output until the detection signal is recognized, Δt ₂ (Δt)
The amount of overshoot, that is, the error δ of the detector 1 in is expressed as δ=V ₃ ·Δt ₂ (2). Therefore, if the speed V ₃ is set to a low speed or a very small speed, the error δ can be made extremely small. In addition, the speed V ₂ is unrelated to the measurement, so it is assumed to be a fast feed, and the speed V ₁ may have some error, so if the allowable speed of the fastest detector 1 is set, then the speed V ₃ is set to a slow or minute feed. Even if it is measured as speed, the distance traveled is limited to a small range, so without compromising measurement accuracy,
Moreover, it is possible to increase measurement efficiency. For example, from the reference position P ₀ of detector 1 to detector 1
Under the conditions that the distance ₀ (actually unknown) until contact with the workpiece W is 10 mm and Δt = 5 m sec, and the speeds V ₁ , V ₂ , and V ₃ are all high speeds such as 2000 mm/min, Although the measurement time is less than 1 second, the measurement error is up to 166 μm. On the other hand, the speeds V ₁ , V ₂ , and V ₃ are all 10 mm/min.
At a low speed like , the measurement error is about 0.8μm.
However, the measurement time is 1 minute or more. Furthermore, the speed V ₁ is 2000 mm/min, and the speed V ₂ is
Assuming 1000mm/min and speed V ₃ of 10mm/min,
The measurement accuracy is the same as that of about 0.8 μm, and the measurement time is about 1.4 seconds even if the overshoot amount is 2 mm. Therefore, if the feed rate is controlled under the following conditions, the measurement time can be significantly shortened without reducing measurement accuracy. On the other hand, in the determination made by the AND circuits 22 and 24, if there is a foreign object when the probe 1A first outputs the contact signal and it falls while moving in the opposite direction by the amount of servo error, the probe 1A will be separated from the workpiece W and Since the level detection signal is being applied to the AND circuits 22 and 24, the AND circuit 24 outputs an H level signal. Then, since the flip-flop 30 is set, the H level signal from the set output terminal Q of the flip-flop 30 is given to the AND circuit 33 and is also used as the reverse feed command signal RS.
It is given to the main part 51 of the NC device. This results in
The main part of the NC device 51 moves the detector 1 from the position P ₂ ′ where it was moved in the opposite direction by the servo error amount in the previous step.
The detector 1 is moved at a speed _V3 , which is a low or very small speed, in the direction opposite to the previous stroke, that is, in the direction in which it comes into contact with the workpiece W. In the process of detector 1 moving at speed V ₃ ,
When the probe 1A reaches a position P where it contacts the workpiece W, an H level detection signal is provided to the AND circuit 33 of the control section 4 through the signal detection circuit 3.
Since the flip-flop 30 is in the set state, that is, the AND circuit 33 is in the state where the H level signal is applied from the set output terminal Q, when the clock signal from the timer circuit 25 is applied,
Generates H level output. Then, the H level output from the AND circuit 33 opens the gate circuit 35 in the same manner as above, and the measured value data of the first storage means 53 at this time is transferred to the fourth storage means 3.
At the same time, the flip-flop 29
is reset and set to the initial state. Therefore, even if there is a foreign object attached to the workpiece W, it is determined when the workpiece W is moved in the opposite direction by the servo error amount, and the probe 1A moves to the workpiece W again.
As a result of measuring by moving it in a direction that touches the surface, it is possible to prevent measurement errors caused by foreign objects. Furthermore, the measurement efficiency in this case depends on the size of the foreign object, but considering that the foreign object is such that it adheres to the workpiece W, it is possible to achieve a high efficiency that is approximately the same as in the above-mentioned example. In addition, FIG. 4 shows a time chart of various signal waveforms of the control unit 4 and the detector 1 when there is no foreign object.
FIG. 5 shows a time chart of various signal waveforms of the control section 4 and a speed change of the detector 1 when a foreign object is present. Although the diameter of the contact end of the probe 1A has been ignored in the above description, it is actually necessary to correct the diameter of the contact end. In addition to measuring missing diameters, it can also be used for hole core measurement, automatic centering, concentric hole machining, etc. Although FIG. 2 in the above embodiment shows the configuration of the control unit 4 as a logic circuit as hardware, recently, CNC (Computerized
In the case of a numerical control device (Numerical Control Device) type, the control section 4 does not need to be configured as a specific logic circuit, and can be replaced with a group of program instructions. Such a program command group is read out and executed as a subprogram in the CNC device in response to an interrupt signal every Δt. Therefore, the main steps of this program command will be explained. Now, when the machine (detector) is moving at a speed of V ₁ and an interrupt signal is given, the signal detection circuit 3
The presence or absence of the output of the signal detection circuit 3 is checked, and when the output of the signal detection circuit 3 is "present", the interpolation calculation within the CNC device is stopped, and the servo error amount at this time is stored in the register (the third register in the above embodiment).
(corresponding to the storage means 28). Eventually, when the machine is stopped after moving by the servo error, the contents of the register are given to the drive system of the machine as a command value, and the machine is moved at a speed _V2 in the opposite direction to the moving direction at the speed _V1 . Command it to move. Next, when the movement corresponding to the servo error is completed, the presence or absence of the output of the signal detection circuit 3 is checked, and if it is "present", a movement command is issued at a low (fine) speed V ₃ in the same direction as the speed V ₂ . Low (slight) when “no”
Give a movement command at speed V ₃ in the opposite direction to speed V ₂ . While moving at this low speed _V3 , changes in the output of the signal detection circuit 3 are checked, and if there is a change, the supply of command pulses (Δx/ΔT) is stopped.
Then, the content of the first storage means at this time is transferred to the register, and if necessary, an instruction is given to display the value. The main program commands have been explained above, but a skilled programmer can easily create a series of programs that operate in response to interrupt commands by referring to Figure 2. It is. In addition, in the above embodiment, the present invention is mounted on a machining center, but the present invention is not limited to this, and can also be applied to, for example, an NC horizontal boring machine, and is not limited to machine tools. It can also be applied to devices, for example coordinate measuring devices. As described above, according to the present invention, it is possible to provide a measurement method and a measurement device that can improve measurement efficiency while maintaining measurement accuracy, and further eliminate measurement errors caused by foreign objects.

[Brief explanation of drawings]

The figures show one embodiment of the present invention; Fig. 1 is an explanatory diagram showing the entire system, and Fig. 2 is an explanatory diagram showing the control section.
FIG. 3 is an explanatory diagram showing the movement of the detector, and FIGS. 4 and 5 are time charts of various signal waveforms of the control section. 1...Detector as detection means, 2...Drive device as drive means, 4...Control section as control means, 5...NC device, 6...Position detection device as position detection means, 21, 26...AND circuit and flip-flop as contact state indicating means;
22, 24, 29, 30... AND circuit and flip-flop serving as measurement direction determining means, 28...
...Third storage means which is a braking distance storage means, 3
1, 33, 36...AND circuit and fourth storage means constituting measurement position output means, 51...Main part of NC device serving as command means and first to third movement command means, 52... First storage means, 53...second storage means.

Claims (1)

[Scope of Claims] 1. A detection means that generates a detection signal upon contact with and separation from an object to be measured, a drive means that moves the detection means and the object relative to each other, and a drive means that connects the detection means and the object to be measured. a command means for outputting command value data for commanding relative movement with the object to be measured; a position detection means for detecting a relative position between the detection means and the object to be measured and outputting the relative position data; In a measurement method that performs measurement using a measuring device equipped with a control means that controls a driving means and measures a position of contact and separation between an object to be measured and a sensing means, the driving means moves the object to be measured and the sensing means. Stores the difference between the command value data and the relative position data when the sensor is relatively moved and receives a detection signal from the sensing means due to their contact, and drives the driving means to further move relative in the same direction by the difference. Then, after relatively moving by the difference in the direction opposite to the direction of the relative movement, the detection signal from the detection means is determined, and if the detection signal is a signal associated with contact, the detection means and the object are When the detection signal is a signal associated with detachment, the detection signal and the object to be measured are moved relative to each other in a direction away from the object to be measured, and when a detection signal from the detection means is received during this relative movement. A measuring method characterized by outputting contact position data of the position detecting means as a measured value. 2. In claim 1, the speed at which the detecting means and the object to be measured are relatively moved in the opposite direction by the difference memorized at the time of contact is high speed, and the detecting means and the object to be measured are moved at a high speed. A measuring method characterized in that, based on the result of determining the detection signal, the speed of relative movement in the direction away from or in the direction of contact is set at a low speed. 3. A detection means that generates a detection signal as it approaches and separates from an object to be measured, a drive means that moves the detection means and the object relative to each other, and a drive means that causes relative movement between the detection means and the object to be measured. a commanding means for outputting command value data for instructing; a position detecting means for detecting the relative position between the detecting means and the object to be measured and outputting the relative position data; and controlling the driving means based on the detection signal. A control means for measuring the contact/separation position between the object to be measured and the detection means, the control means comprising: a contact state indicating means for outputting a contact state signal when receiving a detection signal associated with the contact; braking distance storage means for storing the difference between the command value data and the relative position data as a braking distance when receiving a status signal; and relatively moving the object to be measured and the detection means in a proximal direction at a first speed. and a first movement command means for relatively moving the object by the braking distance in the same direction when receiving the contact state signal; and a second movement command means that is activated following the first movement command means and moves the object to be measured and the detection means a second movement command means for causing a relative movement by the braking distance in the opposite direction at a speed; and a second movement command means that is activated subsequent to the second movement command means and specifies the reverse direction if the detection signal is in a contact state, and the detection signal is measurement direction determining means for specifying the approaching direction if in the detached state; a third movement command means for relatively moving at a third speed, which is a low speed; A measuring device comprising: a measuring position output means for outputting a measured position;