JPH0510777A - Measuring instrument equipped with function of automatically adjusting offset - Google Patents

Abstract

PURPOSE:To shorten the time for arrangement before actual measurement by automatically adjusting an offset value by means of calculation of the value from data at one part of a pre-area preceeding a measuring area or of the measuring area, the offset value being added to display, or printing, outputs. CONSTITUTION:In a measuring instrument which measures the surface configuration of a subject to be measured and displays or prints it, a pre-area preceeding a measuring area is set in order to avoid the transient response of a driving system. Because the properties of the pre-area for flat subjects to be measured resemble those of the measuring area, the average value of the pre-area approximates that of the measuring area. Therefore the average value of the pre-area is used as an output offset value so that offset adjustment is automatically carried out in such a way that a zero point on the display screen serves as a starting value of measurement. When the surface area of a subject to be measured is too small to provide a wide pre-area, data at some part of the measuring area may be averaged to compute an output offset value which is utilized to provide similar displaying or printing methods.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a measuring machine for detecting and displaying or printing the state of a measuring object, and particularly to a front section or a measuring section preceding an measuring section with an offset value for adjusting the display or print output. The present invention relates to a measuring instrument with an automatic offset adjustment function, which calculates from some data of itself and automatically adjusts.

[0002]

2. Description of the Related Art The properties of the surface of an object are
It is called roughness, waviness, contour (shape), etc. The surface texture measuring machine detects such a texture of the surface of an object with high accuracy using a contact type or non-contact type detector. Some surface texture measuring machines using a contact type detector (stylus) can measure a full stroke of 0.5 mm with a resolution of several thousandths. Such a high-resolution measuring instrument has a plurality of measurement ranges with different magnifications, and the measurement ranges can be selected so that the range to be measured can be displayed with as large an amplitude as possible. In addition, it is necessary to adjust the offset value added to the measurement value.

[0003]

However, in the conventional measuring machine, since the optimum range is selected and the offset value is adjusted while repeating the preliminary measurement, it takes time to set up before the actual measurement can be performed. In particular, in a measuring machine using a contact type stylus, there is a concern that the measurement object surface may be damaged by repeating the measurement many times.

For example, the offset adjustment includes a detector offset adjustment and an enlarged recording graphic display or print output offset adjustment. When the former adjustment result affects the latter, both adjustments are repeated. There is a drawback that it takes time to prepare for the measurement.

It is an object of the present invention to automate the offset adjustment to shorten the setup time until the main measurement and facilitate the measurement.

[0006]

In order to achieve the above object, the present invention provides means for detecting the state of a measurement object, means for sequentially sampling and processing the measurement values detected by the detection means, and this processing. Means for displaying or printing the processing result of the means, and means for calculating an output offset value for zeroing the display or print output of the front section from the partial measurement value of the front section preceding the measurement section by the detecting means The first feature is that it comprises an offset adjusting means for adjusting the display or print output of the measurement section with the output offset value.

Further, means for detecting the state of the object to be measured, means for sequentially sampling and processing the measured values detected by the detecting means, means for displaying or printing the processing results of the processing means, and the detecting means. Means for calculating an output offset value for zeroing the display or print output of a part of the measurement section by means, and adjusting the display or print output of the rest of the measurement section with this output offset value The second feature is that the offset adjusting means is provided.

[0008]

According to the structure of the present invention, even if the magnification for displaying or printing a recorded figure is arbitrarily set, the offset commonly included in the detection data is canceled, so that the figure to be displayed or printed may be overwritten. It becomes difficult to range, and it is possible to easily obtain an enlarged recorded figure without failure. For the same reason, the detected data may have an offset,
Even if the positioning and offset adjustment of the detector are rough, operability is improved.

[0009]

1 and 2 show a CPU to which the present invention is applied.
It is a divided block diagram of a built-in type surface texture measuring machine.
FIG. 1 is a partial block diagram mainly showing a CPU and its input / output circuit. On the other hand, FIG. 2 is a partial block diagram showing a configuration peculiar to the surface texture measuring machine. The common bus 10 connecting these figures includes an address bus, a data bus, a clock line, and the like.

In FIG. 1, 11 is a control center CP.
U (central processing unit). The CPU 11 performs regular processing and aperiodic processing, but the real-time clock generator 11a uses the output clock for a fixed time (for example, 5 m).
An interrupt is issued every s), and periodical processing is repeatedly executed. The CPU 11 uses the memory 12 via the common bus 10. The memory 12 includes a RAM (random access memory) and a ROM (read only memory). Of these, the ROM mainly stores operation programs for the CPU 11 and constant tables for various processes. On the other hand, the RAM is used for storing various measurement conditions and collected data, and is backed up by a battery or the like as necessary so that the data is not lost even after the power is turned off.

Around the CPU 11, output devices such as a printer 13 and a CRT display 14 and input devices such as a keyboard 15, a mouse 16 and a switch 17 are connected. The printer 13 is for printing out various measurement conditions, collected data, and the like in characters, graphs, etc. For this interface, for example, a Centronics type output circuit 12a is used. The CRT display 14 displays the measurement conditions, measurement data, etc. stored in the video memory 14b on the CRT screen. The CRT control circuit 14a controls the horizontal sweep and the vertical sweep of the display 14, and controls the read and write of the video memory 14b.

The video memory 14b contains a display 1 when a color graphic display is used, for example.
Color information of each pixel displayed in No. 4 is stored. FIG. 3 shows an example of the display screen. In this example, one screen is divided into a plurality of areas, and an enlarged recorded figure showing the surface roughness is displayed in the large area A. The vertical axis of the enlarged recorded figure display portion A is the degree of unevenness (amplitude), and the horizontal axis is the distance (detector feed position described later). In addition to this, there is a stylus position display portion B, an icon display portion C, and the like.

The keyboard 15 has alphabet keys, numeral keys, etc., and the ON information of each key is encoded by the encoding circuit 1.
5b is coded and input to the CPU 11. Reference numeral 15a is a key input circuit used at this time. Mouse 16 is 2
A shaft encoder and a switch are incorporated, and the encoder output is counted by the counter 16b. The count value of the counter 16b is input to the CPU 11 via the mouse input circuit 16a. At this time, the switch signal of the mouse 16 is also input to the CPU 11 via the mouse input circuit 16a.

The switch 17 is various push button switches,
The switch 11 includes a selection switch, a limit switch, and the like.
To enter. The signals required in the examples described later include manual operation signals that give instructions for detector up / down, left / right direction, etc., automatic operation signals such as measurement start, and operation stroke over signal of the mechanism part. There is.

On the other hand, the configuration of FIG. 2 includes a roughness detector 21, a recorder 22, a detector feed position scale 23, a detector feed unit 24, a column 25, and a tilt correction stage 26. The roughness detector 21 detects irregularities on the surface of the object to be measured, for example, by bringing a mechanical contact point into contact with the surface of the object to be measured and moving the needle as necessary. Since the output of this detector 21 is low in level and susceptible to noise, it is input to the noise removing bridge 21a, and its output (sine wave signal) is input to the synchronous rectifier 21b. Since the bridge 21a and the synchronous rectifier 21b both receive the sine wave signal from the oscillator 21c, synchronous rectification at this portion outputs only a DC voltage corresponding to the vertical displacement of the stylus. The output of the synchronous rectifier 21b is amplified by an amplifier 21d for determining the measurement range (magnification), and then the A / D
It is converted into a digital signal by the converter 21e, and is taken into the CPU 11 through the detector signal input circuit 21f.

In addition to the basic structure described above, the adder 27a
At, the offset voltage for zero adjustment is added. This offset voltage enables the zero point to be determined independently of the displacement of the stylus, and is output from the CPU 11. However, since the output of the CPU 11 is a digital quantity, this is output to the D / A converter 27 via the offset output circuit 27c.
It is input to b and used here after being converted into an analog voltage. On the other hand, a range switching signal for switching the amplification degree of the amplifier 21d is output from the CPU 11, and the range switching output circuit 2
It is given to the amplifier 21d via 8a. Since the amplification degree of the amplifier 21d can be changed by changing the value of the range switching signal, it is possible to display or print at the enlargement magnification suitable for the measurement data.

Since the recorder 22 mainly records the stylus displacement as a waveform, the CPU 11 multiplies the stylus displacement value by a predetermined constant value and outputs the result to the recorder output circuit 22a. Output through. Since the output of this output circuit 22a is a digital value, it is D / A
It is converted into an analog value by the converter 22b and input to the recorder 22.

The above-mentioned parts relating to the roughness detector 21 and the recorder 22 relate to the detection and recording of the surface texture measuring device, and from the detector feed position scale 23 to the tilt correcting stage 26 which will be described later. The present invention relates to a mechanism portion for optimizing the positional relationship between a measurement object to be measured and a stylus and sliding a detector.

The detector feed position scale 23 is a parallel position when the roughness detector 21 (here, a mechanical stylus is assumed) is fed in a direction parallel to the surface of the object to be measured, that is, the display 14 or the like. This is a scale for detecting the position in the horizontal axis direction of the enlarged recorded figure in the recorder 22. When the scale 23 is an incremental type, it takes an output form that one pulse is generated for each predetermined movement amount.
This pulse is counted by the counter 23b in the subsequent stage, and the total amount of movement from the start position (this is called the detector feed position)
Ask for. Since the CPU 11 needs this feed position for display and print control, it transfers it to the CPU 11 via the feed position input circuit 23a.

If the counter 23b has a function of generating a distance signal for each predetermined feed position, the CPU 11 can be interrupted by this distance signal. Since this interrupt corresponds to the actual position of the detector 21, it can be conveniently used for display or recording control in addition to the time interrupt by the real-time clock.

The detector feed unit 24 is a mechanism for moving the detector 21 in the horizontal direction (direction of arrow H) as shown in FIG. The above-mentioned scale 23 is the feeding unit 2
The movement amount of the detector 21 by 4 is measured. The feed unit 24 can be moved up and down by the column mechanism 25, whereby the distance in the vertical direction (direction of arrow V) from the measurement object (workpiece) 30 can be arbitrarily adjusted. Measured object 30
Is a table for tilt correction (auto leveling table) 26
It is placed on the surface and the horizontal degree (angle θ) is arbitrarily set within a predetermined range.
Can be adjusted. Reference numeral 31 is a surface plate that keeps the stage 30 and the feed unit 24 in a stable positional relationship.

A DC electric motor, for example, is used as a drive source for the detector feeding unit 24. In this case, the CPU 11 outputs a feed speed command signal to control the feed position of the feed unit 24. This feed rate signal (digital amount) is taken in by the feed rate output circuit 24a, and the D / A converter 2
4b is converted into an analog quantity. A pulse width modulator 24c is used to convert this analog voltage into a drive signal, and its output is used as a drive amplifier 24d of a DC drive motor.
To enter.

When, for example, a pulse motor is used as the drive source of the column mechanism 25 for vertically moving the detector feed unit 24, the vertical movement data output from the CPU 11 is taken in by the vertical movement output circuit 25a, and this is generated.
Convert to pulse train at b. This pulse is generated so that there is one pulse per unit movement amount, and the pulse counter 25c
Is counted in. Then, this count value is used as the driving amplifier 25d.
The vertical movement amount of the column mechanism 25 can be controlled by inputting into the column.

When a pulse motor is used as the drive source of the tilt correction stage 26 for adjusting the levelness of the object 30,
The correction angle output circuit 2 receives the correction angle data from the CPU 11.
Capture with 6a. After that, as in the case of the column 25, the pulse generator 26b, the pulse counter 26c, the drive amplifier 26
The pulse motor is driven using d to adjust the inclination of the stage 26 on which the measured object 30 is placed.

In such a measuring instrument, two types of offset adjustment are required. One is the offset adjustment of the detector 21, which is performed by processing the output value to the offset output circuit 27c. The other is offset adjustment for display or print output.

The present invention relates to the latter offset adjustment. Specifically, regardless of the output operation of the offset output circuit 27c, the detector signal input from the detector signal input circuit 21f is multiplied by a range constant, Further, the output offset adjustment for obtaining the display or recording output by multiplying the magnification constant for the display or recorder 22 is performed (generally, the output offset value is subtracted).

Examples of the present invention will be described below. Figure 5
FIG. 3 is an explanatory diagram of an embodiment of the present invention. For measuring instruments that measure and display or print the surface properties of the measurement object, in order to avoid the transient response of the drive system or to avoid the influence of the transient state in the filter calculation, before measuring the desired measurement interval. A storage interval may be set. FIG. 7A is displayed assuming the measurement data when such a front section and a measurement section are continuously measured by the same detector.

Generally, since the front section of the object having a flat shape is similar to the property of the measurement section, the average value of the front section is close to the average value of the measurement section even if there is a difference in surface roughness. have. Therefore, if the average value of this front section is used as the output offset value of the measurement section display, the measured data of the desired measurement section will be used as the measurement start value at the zero point on the display surface as shown in FIG. 5B. The offset is adjusted automatically. Therefore, it is possible to observe the surface properties in detail using a high range. The data used for calculating the average value in the front section may be the whole or a part of the front section.

In some cases, the surface of the object to be measured has a small area and the front section cannot be sufficiently taken. In such a case, the output offset value may be calculated by averaging data of an arbitrary part of the measurement section, and using this, the same display or print form may be used. For example, one example is to calculate an output offset value from the data of the beginning part of the measurement section and apply it to the remaining part.

6 to 8 are flowcharts of various tasks 1 to 3 showing the processing of the present invention. Of these, task 1
Is a process relating to the feed control of the detector 21 and the sampling of the detector signal, which is executed regardless of whether the front section is set or not. On the other hand, task 2 is processing relating to output offset adjustment and recorder output control, which is executed when the front section is not set. Task 3 is processing relating to output offset adjustment and recorder output control, which is executed when the front section is set.

Task 1 is combined with task 2 or task 3, and the set of tasks 1 and 2 (or the set of tasks 1 and 3) can be apparently executed simultaneously by a multitasking real-time monitor.

First, details of task 1 in FIG. 6 will be described. The first step S1 of this task 1 relates to preparation for sending the detector. Here, the preset offset value is output to the offset output circuit 27c, and the preset range number is output by range switching. Output to the circuit 28a. In the next step S2, the feeding of the detector is started. That is, the preset detector feed speed is output to the feed speed output circuit 24a.

In the following step S3, it is determined whether or not a front section preceding the measurement section is set. If it is determined that there is no setting, the process branches to step S4, and if it is determined that there is a setting, the process branches to step S9.

In step S4, the detector signal is sampled. That is, the detector feed position signal is input from the feed position input circuit 23a, and the detector signal is fetched from the detector input circuit 21f at preset sampling intervals.

In step S5, the size of the sampling number is judged on the basis of m samples. If it is judged to be less than m, the process returns to step S4, and if it is judged to be m or more, step S6 is executed. In this process, when the front section is not set, a part of the measurement section for calculating the output offset value (total of n pieces of data), m pieces (m <n) at the head portion in this example. It is to determine whether or not all the data have been sampled.

In step S6, task 2 in FIG. 7 is activated, and then the process proceeds to the next step S7. Since the task 2 starts executing from this point, the task 1 and the task 2 are simultaneously executed by the real-time monitor.

In step S7, it is determined whether or not the sampling of the detector signal data of the total number (n) of data in the measurement section is completed. If it is determined that the number is n or more, the process proceeds to step S8. If it is determined that the number is less than n, the process proceeds to step S8.
Return to 4. When the number is less than n, the task 2 is activated each time the loop from step S4 to step S7 is passed, but the task 2 is activated no more than the second time, so there is no problem.

In step S8, the feeding of the detector is stopped. That is, the zero signal is output to the feed speed output circuit 24a to stop the feed of the detector 21.

On the other hand, when it is determined in step S3 that the front section is set, step S4 is performed in step S9.
Perform the same processing as. However, in the subsequent step S10, the size of the sampling number is determined on the basis of k (the total number of data in the front section) different from step S5. If the number is less than k, the process returns to step S9. If it is determined that the number is k or more, the task 3 is activated in step S11 and then the process proceeds to step S12.

In step S12, the size of the sampling number is determined with reference to (k + n), and if it is less than (k + n), the process returns to step S9, but if it is determined to be (k + n) or more, the process proceeds to step S8. Stop the detector feed with. This (k + n) number is the total number of data in the front section and the measurement section. Incidentally, from step S12 to step S9
Even if it returns to step S11, the activation of the task 3 in step S11 is valid only for the first time, and no work is performed for the second time and thereafter. This is similar to the case of step S6.

FIG. 7 shows details of the task 2 started when there is no setting of the front section. In the first step S21 of this task 2, the output offset is calculated. Specifically, an average value is obtained for m pieces of data from the beginning of the sampled detector signal data, and this is used as an output offset. In the next step S22, from the first data of the sampled detector signal data to step S21
Subtract the output offset obtained in.

Hereinafter, in the loop processing of steps S22 to S26, the output offset adjustment is sequentially performed one by one from the first detector signal data every time step S22 is executed. In this case, the processing up to step S22 is performed on the input value itself from the detector signal input circuit 21f without considering the magnitude of the signal due to the range.

On the other hand, in step S23, the multiplication of the range constant is performed in order to consider the magnitude of the signal according to the range. That is, when the range constant determined by the range number output to the range switching output circuit 28a is S and the expansion constant determined by the recording magnification set in advance for performing recorder output is R, the above step S
The output offset adjustment result obtained at 22 is multiplied by the range constant S and the expansion constant R, respectively. Then, in the next step S24, the multiplication result of step S23 is output to the recorder output circuit 22a.

In step S25, the number of times the recorder output in step S24 is performed is determined by the total number n of data in the measurement section.
Compare with the individual. Here, if it is determined that the number is n or more, the task 2 ends, but if it is determined that the number is less than n, step S2.
Proceed to step 6 and wait for the next data to be sampled.

That is, from step S22 to step S2
In 6, the processing of 1 data is performed per loop. For this reason, in step S26, the detector signal data to be processed next ((i +
1) data) is already sampled in task 1, and if not sampled,
Wait for it to be sampled. If it is determined in step S26 that the next data has been sampled, step S2
Returning to step 2, the same processing as described above is repeated.

FIG. 8 shows details of the task 3 started when the front section is set. In this task 3, the detector signal data in the front section can be used, so in the first step S31, an average value is obtained for k sampled front section detector signal data, and this is used as the output offset.

In the next step S32, the output offset obtained in step S32 is subtracted from the (k + 1) th data of the sampled detector signal data, that is, the first data of the measurement section. Similarly, the following steps S32
To repeat the loop process from step S36 to 1
The same subtraction process is performed on one data (n data in the entire measurement section) per loop.

In the following step S33, the output offset obtained in step S32 is multiplied by the range constant, as in step S23 of FIG. Then, step S34
Then, the result of step S33 is output to the recorder output circuit 22a. Furthermore, in step S35, step S34
It is compared whether or not the recorder output by the above is performed for the data up to the sum total (k + n) of the numbers of data in the front section and the measurement section.

If it is determined in step S35 that it is the (k + n) th or more, this task 3 is ended, but if it is determined that it is less than the (k + n) th, the processing for the total number n of measurement sections has not been completed. Therefore, the process proceeds to step S36. Similar to step S26 of FIG. 7, this step S36 is a process of waiting for sampling of the next data output by the recorder, and upon completion of this process, the process returns to step S32.

[0050]

The measuring machine with the automatic offset adjusting function of the present invention described above has the following advantages. a) Even if the range magnification used when displaying or printing a recorded figure is arbitrarily selected, the offset that is commonly included in the measurement data is canceled, making it difficult for the figure to be displayed or printed to overrange. It is possible to easily obtain an enlarged recorded graphic output. b) Since the offset amount commonly included in the measurement data is canceled, the measurement data may include the offset. Therefore, the positioning of the detector and the offset adjustment of the detector are rough, and the operability is improved accordingly.

[Brief description of drawings]

FIG. 1 is a partial block diagram of a measuring machine to which the present invention is applied.

FIG. 2 is a remaining block diagram of a measuring machine to which the present invention is applied.

FIG. 3 is an explanatory diagram showing a screen configuration of a CRT display.

FIG. 4 is a mechanism diagram of a surface texture measuring device.

FIG. 5 is an explanatory diagram of an example of the present invention.

FIG. 6 is a flowchart of task 1 showing the processing of the present invention.

FIG. 7 is a flowchart of task 2 showing the processing of the present invention.

FIG. 8 is a flowchart of task 3 showing the processing of the present invention.

[Explanation of symbols]

A ... Enlarged recorded figure display section, 10 ... Common bus, 11 ... CP
U, 12 ... Memory, 13 ... Printer, 14 ... CRT display, 15 ... Keyboard, 16 ... Mouse, 17 ... Switch, 21 ... Roughness detector, 21f ... Detector signal input circuit, 22 ... Recorder, 22a ... Record Meter output circuit, 23 ...
Detector feed position scale, 24 ... Detector feed unit,
25 ... Column mechanism, 26 ... Tilt correction stage, 27c ...
Offset output circuit, 28a ... Range switching output circuit, 3
0 ... Measured object.

Claims (2)

[Claims] 1. A means for detecting the state of a measured object, a means for sequentially sampling and processing the measured values detected by the detecting means, a means for displaying or printing the processing result of the processing means, and the detection. Means for calculating an output offset value for zeroing the display or print output of the front section from the partial measurement value of the front section preceding the measurement section by means, and displaying or printing the measurement section with this output offset value A measuring instrument with an automatic offset adjusting function, comprising an offset adjusting means for adjusting an output. 2. A means for detecting the state of a measured object, a means for sequentially sampling and processing the measured values detected by the detecting means, a means for displaying or printing the processing result of the processing means, and the detection. Means for calculating an output offset value for zeroing the display or print output of a part of the measurement section by means, and adjusting the display or print output of the rest of the measurement section with this output offset value A measuring instrument with an automatic offset adjusting function, which is provided with an offset adjusting means.