JPH0267907A - Device for measuring surface shape - Google Patents

Abstract

PURPOSE:To shorten measurement time by a method wherein a plurality of laser beam distance measuring devices are provided and a surface size of an object to be measured is continuously measured by moving an X-Y table. CONSTITUTION:Analog voltage of a surface shape of an object to be measured, which is measured by a plurality of laser heads 1, 1a, is amplified by an amplifier 6, digitally converted by an A/D converter 7 and input to a microcomputer 8. Then, the computer 8 performs calculation and comparison of the stored data, and the results of measurement are displayed on a CRT 10 while recorded on a printer 9. In an interface 12, input serial data is supplied to an X-Y table 17 via pulse generators 13, 14 and pulse motors 15, 16, so that the object to be measured which has been mounted on the table 17 is continuously moved. Therefore, the object to be measured is continuously measured by the heads 1, 1a to have measurement time shortened.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a measuring device for measuring the smoothness, degree of eccentricity, level difference, etc. of the surface of an object to be measured.
More specifically, the present invention relates to a surface shape measuring device that uses a plurality of laser beam distance measuring devices to continuously and efficiently measure the surface condition of an object to be measured placed on an X-Y table.

[Conventional technology]

2. Description of the Related Art Conventionally, image processing devices have been used to measure and monitor the surface roughness or surface shape of workpieces, electronic components, etc. that require precision. This is the i! obtained by photographing the object to be measured from different positions. ii@ is processed by computer, and an imaging device such as a video camera and a computer with advanced processing capabilities are used.

[Problem to be solved by the invention]

When this method is used, the processing for digitizing the surface condition by performing arithmetic processing from the moving angle of the video camera and the corresponding image is extremely complicated, and the program becomes enormous. Further, in order to use such a device, it is necessary to be technically proficient, making it difficult for the general public to use, and the cost of the device is also extremely high.

The present invention was created in view of these points, and it is an object of the present invention to provide a relatively inexpensive surface shape measuring device that takes a short measurement time, provides accurate numerical values and image output, has excellent workability, and is relatively inexpensive. purpose.

[Means to solve the problem]

The surface profile measuring device according to the present invention measures distances with a plurality of laser beams that generate analog outputs that are proportional to the distance between the object to be measured on the X-Y table and the measuring section, and outputs the analog outputs as digital outputs. an A/D converter for converting the output of the A/D converter, a storage device for storing the output of the A/D converter, and calculating the contents stored in the storage device and displaying the calculation result on a CRT and displaying the object to be measured. It comprises a microcomputer that generates a signal for movement, and a pulse motor that receives the signal and moves the XY table.

[Function] A laser beam distance measuring device that has multiple laser heads that generate analog outputs measures the distance between the object to be measured on the x-y table and the measuring section of the laser beam distance measuring device. . Since there are multiple laser heads, the number of operation steps can be reduced compared to the case where there is a single laser head, and the measurement time can be shortened. The analog output indicating distance is A
/ After being digitally converted by a D converter, it is input to a computer. The computer performs calculations to generate the required numerical output, and also performs processing for displaying on the CRT. Further, a pulse motor is driven by a signal generated by the computer, and the XY table is moved. Movement of the X-Y table and computer processing of the measurement results are performed continuously for a required period of time, and the results are printed out on a printer as necessary.

〔Example〕

Embodiments of the present invention will be described below with reference to FIGS. 1 to 7.

FIG. 1 is a diagram showing the principle of the invention, in which a laser head of a laser beam distance measuring device is designated by reference number 1.1a. Although a plurality of laser heads are installed, two are usually necessary and sufficient due to space constraints. It is preferable that the distance between the laser heads 1 and la can be adjusted manually or automatically depending on the size of the workpiece 3 to be measured. 2 is a measuring section of a laser beam distance measuring device, and the distance between the workpiece to be measured 3 and the measuring section 2 is measured by the laser beam distance measuring device.

Usually, the distance between the measurement unit 2 and the workpiece to be measured 3 is set to a certain distance tilt (reference value), as shown in the figure.

Figure 2 shows the output of the laser beam distance measuring device caused by the relative movement between the laser head and the workpiece to be measured 3, where the horizontal axis shows the scanning distance and the vertical axis shows the output voltage. . Further, in FIG. 2, X indicates a high potential portion generated by a convex portion of the workpiece 3 to be measured, but it is also possible to conversely be configured so that a high potential is generated by a concave portion.

FIG. 3 is a partial view showing an example of an object to be measured 5 including a deformed portion 4, and such deformed portion 4 is also detected as an output of the laser beam distance measuring device. Further, the distance d between the object to be measured 5 of the work to be measured 3 is detected by the relative movement of the laser head Lla and the work to be measured 3.

FIG. 4 schematically shows the output of the laser beam distance measuring device, and shows the distance between the workpiece 3 and the object 5 to be measured.
is shown as the voltage change over time.

FIG. 5(A) is a schematic diagram showing the moving path of the workpiece to be measured 3 when there is a single laser head, and FIG. 5(B) is a schematic diagram showing the moving path of the workpiece to be measured 3 when there are two laser heads according to the present invention.
As described later, various routes can be set by simple programming. As is clear from these figures, if the laser head is quasi-, it must trace all the measurement points, but in the case of two laser heads, at least two sides can be traced by the -movement, which reduces the measurement time. This means that it can be shortened.

FIG. 6 is a block circuit diagram of a surface profile measuring device according to the present invention.

In the figure, reference number 1.1a is a laser head, as described above, which irradiates a measured object with a pulsed laser and measures the distance by counting the time until the reflected pulse returns with a counter. Although what is measured is common, the present invention is not limited thereto. Generally, a semiconductor is used as the power source, and the laser head 1.1a constitutes a laser beam distance measuring device together with devices (not shown) such as a power source. This laser head 1.1a detects the height and pitch distance of the uneven portion of the object to be measured, and outputs an analog voltage based on these. In the figure, reference numeral 6 is an amplifier that amplifies the analog voltage from the laser head 1.1a and supplies a suitable voltage to the following A/D converter 7. Amplifier 6
The output of is set to, for example, a maximum of ±3v. The relationship between displacement and voltage at this time is, for example, 1 mV/1 μm. A
The output of the /D converter 7 is DMA-transferred to a specially provided RAM together with a 16-bit microcomputer 8. The data stored in this RAM is subjected to arithmetic comparison processing using a program prepared in advance, and the results are displayed in real time on a CRT, which will be described later. As this 16-bit microcomputer 8, a commercially available personal computer or the like can be used as is. The microcomputer 8 is connected with a printer 9, CRTIO, keyboard 11, etc. as external devices, and is also equipped with a floppy disk device (not shown). The operator of the microcomputer 8 can easily change parameters using a simple personal computer language or the like. Note that, as will be described later, the measurement results are displayed on the CRTIO and also stored in the printer 9. In the figure, reference number 12 is an interface, which transmits serial data obtained via an external bus such as R3232C of a personal computer to a pulse generator 13.1.
4. Using this serial data, the X-Y table 17 is driven according to the preprogrammed contents, and the drive is controlled so that measurement is performed only when the motor rotates at a constant speed. Further, reference numerals 15 and 16 are pulse motor drivers, which are used to drive a pulse motor (not shown) to move the XY table 17. In order to make it a high resolution device, the pulse motor driver 15.16 is 6000PPS.
It is desirable to use an X-Y table 17 having a response characteristic of ~toooopps, and it is desirable to use an X-Y table 17 with a repeatable positioning accuracy of approximately ±0.003 inch. A 5-phase motor is used as the pulse motor to ensure high resolution and to prevent measurement results from being affected by vibration.

The operating modes of the device include a target work switching mode and a target work selection mode. In the target workpiece switching mode, the X-Y table 17 moves based on various setting data backed up in the memory in advance, regardless of the workpiece, and in the target workpiece selection mode, the The operation data of the XY table 17 thus obtained is stored in the memory. Setting of various parameters such as operation parameters is performed based on input data from the keyboard 11 saved on a floppy disk (not shown) or the like. Note that the reason why a turning trajectory is drawn at each end of the four sides of the schematic diagram in FIG. 5 is to prevent measurement from being performed at the rising and falling portions of the motor. This means that measurements are taken only when the vehicle is running at a constant speed.

The operating modes of the device include an automatic operating mode and a manual operating mode. In automatic operating mode, after changing the workpiece,
It will automatically restart after a certain period of time. In the manual operation mode, the process is restarted by operating a switch (not shown) after replacing the workpiece. The inspection speed can be adjusted by controlling the feed rate of the X-Y table 17, and either stepwise or continuous control can be performed. On the other hand, it is possible to monitor and control the output voltage of the laser beam distance measuring device during scanning. For example, it is possible to change the display contents of the CRTIO when the voltage change width X shown in FIG. .

Parameters such as the allowable value of the voltage change width X can be easily set using the keyboard 11.

Note that the permissible value of the voltage change width X corresponds to the permissible value of the tolerance of the object to be measured.

When using the keyboard 11 manually, settings can be made from both the Ryu standard and the MILL standard. To give an example of the tolerance, the minimum tolerance is 1.22 μm in the Dragon standard, and the minimum tolerance is 0.3 MILL” in the old LL standard.
A maintenance mode is provided for inputting setting data such as the inspection origin, movement range, and movement distance, and operation in this mode is performed when changing the workpiece.

FIG. 7(a) is a flowchart of the apparatus according to the present invention. Next, the control flow of the apparatus according to the present invention will be explained with reference to FIG. 7(a). First, in step 5100, the power is turned on, and then in step stoi, various parameters are set. Next, in step 5102, the object to be measured is set, and in step S10
When the start t indication is given in step 3, step S
At 104, movement of the X-Y table is started. X-Y
As the table moves, sampling, that is, measurement is performed in step 8106. Sampling in step 5106 is continued until the movement of the XY table is completed in step 5105. After each sampling is completed in step 5107, the data is processed in step 310B. usually,
Processing is performed for each sampling of data, and the results are stored in memory within the computer device. When the measurement of one workpiece is completed, it is determined in step 5109 whether or not to change the measurement workpiece. If there is no need to change the measurement work, control moves to step 5102 and the measurement target is set. If the measurement work is changed, the jig to be inspected is replaced in step S110, and control then moves to step S101 to reset the parameters.

FIG. 7Tb) is a flowchart showing an example of steps for determining whether to print and save data to a file when one measurement is completed. In the figure, when a stop signal is generated in step 3120, it is determined in step 5121 whether or not to end the measurement. If the measurement is not to be terminated, control moves to step S122 and the measurement is continued. On the other hand, if it is determined that the measurement is to be completed, it is determined in step 3123 whether or not to print out. If it is to be printed out, printing is performed in step 5124, and if it is not to be printed out, it is further determined in step 5125 whether or not to store it in a file. If it is to be stored in a file, control moves to step 3126, and if it is not to be recorded in a file, step 5127
Control is transferred to , and measurement continues.

〔Effect of the invention〕

As described above, according to the present invention, an accurate numerical output can be quickly obtained with a relatively inexpensive device, and a surface shape measuring device with excellent workability can be obtained.

[Brief explanation of the drawing]

Figure 1 is a diagram of the principle of the present invention, Figure 2 is a graph showing an example of the output of the device according to the present invention, Figure 3 is a partial side view of the workpiece and object to be measured, and Figure 4 is a laser beam. Graph schematically showing how the distance measuring device comes out, Figure 5 (8), (B)
6 is a block circuit diagram of the surface profile measuring device according to the present invention, FIG. 7 fa+ is a flowchart of the device according to the present invention, and FIG. 3 is a partial flowchart of the apparatus according to FIG. Explanation of symbols 1.1a - Laser head, 2... Measuring section 3 -...
Workpiece to be measured, 5--Object to be measured 7--A
/D converter 8...Microcomputer 9...Printer 10...CRTll-.
Keyboard, 12--Interface 13
．． 14...-Pulse generator 15.16...Pulse motor drive 17...X-Y table patent applicant Seiei Kosan Co., Ltd.

Claims (1)

[Claims] (1) A plurality of laser beam distance measuring devices that generate analog outputs proportional to the distance between the object to be measured on the X-Y table and the measurement unit, and an A/D converter that converts the analog outputs into digital outputs. a storage device that stores the output of the A/D converter, and generates a signal for calculating the contents stored in the storage device, displaying the calculation result on a CRT, and moving the object to be measured. and a pulse motor that moves the X-Y table in response to the signal, and the surface dimension of the object to be measured is continuously measured by moving the X-Y table. surface shape measuring device.