RU2164004C2 - Gear measuring linear dimensions of objects - Google Patents

Abstract

FIELD: measurement technology, testing systems. SUBSTANCE: characteristic feature of gear measuring linear dimensions of objects consists in that it incorporates symmetric flip- flop, dimension corrector made of unit determining time misalignment between pulses following one another, adder of codes following one another, two dividers of unit converting duration signal to code, multiplier and panel outputting constant. EFFECT: increased accuracy of determination of linear dimensions of object. 1 dwg

Description

 The invention relates to the field of measuring equipment and can be used in technical control systems.

 A device for measuring the linear dimensions of a moving object, described in patent N 2031362, the authors - Chasovskoy A.A., Yanina T.A. In it, using a laser emitter located on a moving platform, the object is irradiated with a continuous beam. The size of the object characterizes the duration of the signal.

 Due to the irradiation of the control object located in front of the working object, a correction is determined that increases the accuracy of determining the linear dimensions. However, the accuracy of determining the range is affected by the uneven movement of the platform.

 A device for determining the range described in A.S. 1610269, authors Chasovskaya A.A., Yanina T.A., in which a measured object is irradiated with a continuous laser. The radiation source is rigidly connected to a movable platform controlled by the drive. The reflected light energy enters the laser receiver, where it is formed into electrical signals that enter the amplitude selector. The latter gives a signal at the moment of changing its amplitude, which takes place at the moments of the beginning and end of the irradiation of the object.

 During the irradiation period of the object, a trigger is triggered. The signal from the trigger output gives permission to the coincidence element to pass pulses through it from the output of the photodetector, which is part of the speed sensor, which, together with a low-power light source, moves along with the movable platform along a fixed ruler with slots. As a low-power light source, a low-power laser can be used, the beam from which hits the photodetector when passing through the slot of a fixed ruler. Thus, the number of pulses from the output of the photodetector depends on the speed of the platform. The number of pulses from the photodetector is calculated using a counter and displayed on the indicator, which is set together with the counter to its original state after the measurement is completed using the reset panel. However, the accuracy of determining the size depends on the number of slots in a fixed ruler. Using the proposed device increases the accuracy of sizing.

 This is achieved by using instead of a trigger, a symmetric trigger and introducing a size corrector, consisting of a unit for determining the temporal mismatch between successive pulses, an adder of successive codes, two dividers, a unit for converting the signal duration to code, a multiplier and a constant output panel, at the output of the coincidence element is connected through the first input of the size corrector, through the unit for determining the temporary mismatch between successive pulses, through the sums anator of successive codes with the first input of the first divider having a second input and output, respectively connected through the second input of the size corrector to the output of the counter and with the first input of the second divider, the second input and output of which are respectively connected to the output of the constant output panel and to the first the input of the multiplier having a second input and output, respectively connected through a signal-to-code converter, a third input of a size corrector with an output of a symmetric trigger, and through an output of a size corrector with the first indicator input.

 The following notation is used in the drawing and in the text.

1 - radiation source;
2 - laser receiver;
3 - drive;
4 - movable platform;
5 - amplitude selector;
6 - symmetric trigger;
7 - element of coincidence;
8 - speed sensor;
9 - photodetector;
10 - fixed ruler with a slot;
11 - low-power light source;
12 - counter;
13 - size corrector;
14 is a block for determining a temporary mismatch between successive signals;
15 - adder of successive pulses;
16 - divider;
17 - block converting the duration of the signal into code;
18 - multiplier;
19 - divider;
20 - panel issuing constants;
21 - reset panel;
22 - indicator;
wherein the output of the coincidence element 7 through the first input of the size 13 corrector, through the time mismatch determining unit between successive pulses 14, through the adder of the consecutive codes 15 is connected to the first input of the divider 16 having a second input and output, respectively connected through the second input of the size 13 corrector with the output of the counter 12 and with the first input of the divider 19, the second input and output of which are respectively connected to the output of the constant output panel 20 and to the first input of the multiplier 18 having a second od and output, respectively connected through a signal duration converter to code 17, the third input of size 13 corrector with the output of symmetric trigger 6 and through the size corrector input with the first input of indicator 22 having a second input connected to the output of the reset panel 21, also connected to the first input of the counter 12, the second input of which is connected to the aforementioned output of the matching element 7, the first and second input of which are respectively connected: through a symmetric trigger 6, through the amplitude selector 5 with the laser output when ISRC 1 and output via the speed sensor 8 in a yield of photodetector 9, an optical input of which is connected with a low-power optical output of the light source 11, is rigidly associated with the aforementioned photodetector 9, the radiation source 2 and the movable platform 4 having a rigid connection with the drive 3.

 The operation of the device is as follows.

 Before starting work in conditions of constant illumination of the object, the amplitude selector 5 is calibrated, with the help of which the beginning and end of the object are determined. A radiation source 2, which may be a helium-neon cw laser emitter, emits light energy with a narrow radiation pattern. The radiation source 2 is located on a movable platform 4, moving along the measured object using the drive 3. The distance over which the movable platform 4 moves, is chosen so as to irradiate the entire size of the object.

 The light energy reflected from the object is received by the laser receiver 1, also located on the platform 4. It converts the light energy into electrical signals supplied to the amplitude selector 5. The amplitude selector gives a signal about the beginning of the irradiation of the object at the moment the amplitude changes to the input of the symmetric trigger 6. Amplitude selector 5 gives a second signal at the moment of irradiation of the object, setting the symmetric trigger 6 to its initial state. The duration of the signal at the output of the symmetric trigger is The size of the object. A low-power light source 11, which can be a low-power laser and a photodetector 9, is rigidly connected and moves with it with a movable platform 4, and a fixed ruler with slots 10 is located between them. A light beam passes through these slots. A photodetector 9 converts light energy into electrical signals.

 The repetition rate of these signals characterizes the speed of the movable platform 11 with the radiation source 2. The above nodes 9, 10 and 11 are part of the speed sensor 8, the output of which successive pulses pass through coincidence element 7 in the presence of a signal from a symmetric trigger 6 to the input of the counter 12 and to the corrector of size 13, to the input of the block for determining temporary discrepancies between successive pulses 14. Counter 12 counts the number of pulses from the photodetector 9 during the irradiation of the object, and the block 14 provides time codes between successive signals from the photodetector 9 during periods of irradiation of the object.

 The execution of block 14 does not differ from the range converter, presented, for example, in the book "Reference book on radio location". M .: Higher school, 1977

 These codes are added in the adder of the successive codes 15. The average value of the time mismatch code is determined in the divider 16, where the sum of the codes is divided by the information on the number of pulses coming from the counter 12. The average value of the time mismatch is divided in the divider 19 by the reference value of the time mismatch coming from the panel issuing the constant 20. It is determined during the calibration process, which is carried out as follows.

 In the process of measuring the size of the control object, the divider 16 is disconnected from the divider 19 and connected to the control digital indicator, which fixes the average value of the time mismatch. This value is stored and entered during operation from the panel issuing the constant 20. As a result, at the output of the divider 19, there is a correction factor, the value of which depends on the difference between the actual speed of the movable platform 4 and the reference. This coefficient is multiplied in the multiplier 18 by the signal duration code, which is determined in the block for converting the signal duration to code 17.

 As a result, the refined code of the signal duration characterizing the size of the object enters the indicator 22, where it is displayed. After the measurement is completed using the reset panel 21, the information in the indicator 22 is reset and the counter 12 is reset. Thanks to the introduction of the size corrector 13, the accuracy of determining the linear dimensions can be less than a micron. Before measuring a series of parts, the dimensions of the first of them are determined by the usual contact method, and if the tolerances for the manufacture of the part correspond to the norm, its dimensions are measured using this device. Further, these sizes are remembered and compared with the sizes of the following parts, which are displayed on the indicator 22, and it is determined whether they correspond to the tolerance.

 Using the proposed device eliminates the influence of the finiteness of the number of slots in the fixed line of the speed sensor on the accuracy characteristics. At the same time, the factor of the absence of a change in the platform displacement velocity on the accuracy of determining the size is also preserved. This makes it possible to provide accuracy characteristics of less than one micron.

Claims (1)

 A device for measuring the linear dimensions of objects, consisting of a radiation source, a laser receiver, a drive, a moving platform, an amplitude selector, a trigger, a coincidence element, a speed sensor, a photodetector, a fixed ruler with a slot, a low-power light source, a counter, a reset panel, and an indicator, where the second input of the indicator is connected to the output of the reset panel, also connected to the first input of the counter, the second input of which is connected to the output of the matching element, the first and second inputs of which respectively inens with the trigger output, the first input of which is connected through the amplitude selector to the output of the laser receiver and through the output of the speed sensor, with the output of the photodetector, the optical input of which is connected to the optical output of a low-power light source and with a movable platform that has a rigid connection with the drive, characterized in what is the use instead of a trigger, a symmetric trigger and the introduction of a size corrector, consisting of a unit for determining the temporal mismatch between successive pulses, with a matrator of successive codes, two dividers of a block for converting the signal duration to a code, a multiplier and a constant output panel, while the output of the coincidence element is connected through the first input of the size corrector, through the block for determining the temporal mismatch between successive pulses, through the adder, one after another of codes, with the first input of the first divider having a second input and output, respectively connected through the second input of the size corrector with the output of the counter and with the first input of the second an alternator, the second input and output of which are respectively connected to the output of the constant output panel and to the first input of a multiplier having a second input and output, respectively, connected through a signal duration converter to a code, the third input of a size corrector with the output of a symmetric trigger, and through the output of a size corrector with the first indicator input.