RU2446380C1 - Method of estimating deviation of perpendicularity of two axes - Google Patents

Abstract

FIELD: physics.

SUBSTANCE: method is realised by directing the sighting telescope of a first theodolite, operating in autocollimation mode, onto one face of a prism placed on a driven axle and turned about the driving axle by 90° relative the initial position of the device and obtaining the initial reading of the first angle. Further, the sighting telescope of a second theodolite, operating in autocollimation mode, is directed onto the same face of the prism which is turned 180° about both axes of the device relative the previous position and the initial reading of the second angle is obtained. Optical connection of the first and second theodolites with a third theodolite is provided and the final readings are obtained using the first and second theodolites, and the initial and final readings of the third angle are obtained using the third theodolite. Deviation of perpendicularity of two axes of rotation of the device are determined from the difference between the sum of the measured three angles and 180°.

EFFECT: possibility of measuring deviation of perpendicularity of two axes of rotation of devices using a contactless method.

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Description

The proposed method is used to measure and evaluate the deviation from the perpendicularity of the two axes of rotation of the devices, one of which is leading, and the second is driven. Field of technology: metrology, instrument making.

Known schemes and methods for measuring deviations from the perpendicularity of two axes of rotation; two methods presented in GOST 22267-76 “Metal-cutting machines. Schemes and methods of measuring geometric parameters ”have a number of fundamental limitations associated primarily with the features of the applied contact measuring and control tools, such as frame levels and control mandrels. In addition, when determining the investigated parameter, according to known methods, physical accessibility to both axes of rotation of the device is necessary.

The closest set of essential features to the proposed invention is a method of measuring the angle using an autocollimation theodolite, GOST 10529-96. “Theodolites. General specifications. "

The known method consists in the fact that theodolite telescope is pointed at a reflecting surface and an initial reading of the measured angle is obtained.

But in a known manner it is impossible to measure the deviation from the perpendicularity of the two axes of rotation of the devices.

The problem is solved due to the fact that in the present invention, as well as in the known method, the measurements are carried out by pointing the first theodolite operating in the autocollimation mode on one of the faces of the prism mounted on the driven axis and rotated 90 ° relative to the initial position instrument and obtain the initial reference of the first angle. But, unlike the known method, in the proposed one, the telescope of the second theodolite operating in the autocollimation mode is pointed at the same face of the prism, which is rotated 180 ° around both axes of the device relative to the previous position and receives the initial reading of the second angle, and then provides an optical the connection of the first and second theodolites with the third and receive the final samples of the first and second theodolites, and the third theodolite receive the initial and final samples of the third angle, and the difference of the sum of the measured three angles and 180 ° evaluate the deviation from the perpendicularity of the two axes of the device.

Achievable technical result is the ability to measure deviations from the perpendicularity of the two axes of rotation of the devices in a non-contact manner.

The set of essential features formulated in paragraph 2. claims, characterizes a method for estimating deviations from the perpendicularity of two axes of rotation of devices, in which measurements are performed in full tricks.

The invention is illustrated in the drawing, which schematically depicts a sequence of operations for implementing the proposed method. The implementation of the method will be considered taking into account the characteristics set forth in paragraph 2. claims using the example of the use of three accurate autocollimation theodolites 1, 2, 3 of the 3T2KA series and hexagonal prism 4.

Based on the fact that the angular field of the ZT2KA theodolite telescope is 1 ° 35 'and the smallest sighting distance without an additional nozzle is 1500 mm, it follows that theodolites are exposed on tripods with an accuracy of at least ± 20 mm in height.

Next, fix the prism with a mandrel on the driven axis of the device and adjust the position of the prism using theodolite 3 as follows:

Theodolite telescope is exposed so that in the autocollimation mode of the device operation, visually observe the image reflected from the first face of the prism, then, sequentially turning the driven axis of the device by 30 °, make sure that the reflected images from all faces of the prism in the vertical count of the theodolite are within ± 1 '.

Thus, the limit value of the deviation from the perpendicularity of the measuring (working) surfaces of the prism relative to the base angle for the measure of the 2nd (worst) accuracy class will be ± 1'30 '' GOST 2875-88. “Flat-angle measures are prismatic. General specifications. "

The studies described in Yu. V. Filatov, D.P. Loukianov, P.A. Pavlov, M.N. Burnashev, R. Probst. Dynamic ring laser goniometer. Ch. 12 in "Optical Gyros and their Application" / RTO / NATO AGARDograph 339, Neuilly-sur-Seine, France, 1999, p.12-17, show the dependence of the determination of the angle of rotation of a multifaceted prism on the deviation from the perpendicularity of the measuring (working) surfaces of the prism relatively basic.

According to the formula

,

,

where Δφ is the error in determining the angle of rotation of a multifaceted prism;

φ ₀ - the maximum value of the measured angle;

β is the deviation from the perpendicularity of the measuring (working) surfaces of the prism relative to the base.

For the case under consideration (at φ ₀ = 30 ° and β = 90``), the value Δφ will be 0.009 '', which in this case is a negligible value.

теодолитом 1 от первой грани шестигранной призмы. Далее снимают соответствующий отсчет «кругом справа»

и вычисляют первый начальный отсчет теодолита 1 по двум измерениям:After the exhibition of the prism in the horizon, the driven axis of the device is rotated 90 ° around the leading axis (Fig. 1 (a)) and the first initial count is taken "round left"

theodolite 1 from the first face of the hexagonal prism. Next, they take the corresponding count “round right”

and calculate the first initial count of theodolite 1 in two dimensions:

и

теодолитом 2 от 1-й грани шестигранной призмы и вычисляют второй начальный отсчет α₂₁:Next, realizing 180 ° turns of the prism around the driven and driving axes of the device (Fig. 1 (b)), the corresponding horizontal readings are taken in two circles

and

theodolite 2 from the 1st face of the hexagonal prism and calculate the second initial reference α ₂₁ :

Theodolite 3 is set so as to provide optical communication between all theodolites, in other words, the illuminated grid of theodolite 3 filaments should be observed in the eyepieces of theodolites 1 and 2, when the first is rotated through an angle of α ₃ (Fig. 1).

и

теодолитом 1 изображения подсвеченной сетки нитей теодолита 3, при этом фиксируют третий начальный отсчет α₃₁ теодолита 3. Вычисляют горизонтальный отсчет α₁₃ ^: Then theodolite 3 is deployed around its vertical axis in the direction of theodolite 1 so that it is possible to take horizontal readings with both circles

and

theodolite 1 image of the illuminated grid of threads of theodolite 3, while fixing the third initial reference α ₃₁ theodolite 3. Calculate the horizontal reference α ₁₃ ^:

и

и вычисляют α₂₃:Similarly, deploying theodolite 3 around its vertical axis towards theodolite, take readings

and

and calculate α ₂₃ :

In addition, a horizontal reading of α _{32 of} theodolite 3 is fixed.

Finally, having all the input data, the angles α ₁ , α ₂ and α ₃ are calculated:

Then, based on the well-known rule of the sum of the angles of a triangle, calculate the deviation from the perpendicularity of the two axes:

Next, we give an estimate of the error in determining the investigated parameter:

When angles α ₁ and α _{2 are found,} respectively, by theodolites 1 and 2, the measurements are carried out in two circles, which eliminates the collimation error of theodolites.

Finding the angle α _{3 is} calculated from the readings obtained by theodolite 3 in one circle, respectively, the error of this measurement is the passport value of the value of the collimation error of theodolite 3T2KA:

In addition, according to GOST 10529-96. “Theodolites. General technical conditions "the value of the collimation error for theodolites with an autocollimation eyepiece may exceed the passport value, but not more than 50%, therefore:

Before the start of measurements, all three theodolites are placed in the plane of the horizon at cylindrical levels with alidade of horizontal circles, with a division price of 15 ``, so the possible error of the exhibition is 7.5 ''. Thus, based on the passport data of theodolites of this series, the systematic compensation error is calculated. On 1 'of the inclination of the vertical axis of the device relative to the normal to the horizon, the measurement error is 0.8' ', therefore, with a corresponding slope of 7.5' ', the measurement error of one theodolite will be:

However, since all samples are taken at a horizontal angle, this error can be ignored.

The measurement errors caused by the presence of ren and parallax of the reading device of theodolites do not exceed 4.5 '' in total.

Important: measurements are made by theodolites, which have passed the mandatory periodic verification and have a corresponding certificate of verification from the metrological services of the Russian Federation. The same applies to a measure of a flat angle.

Thus, the total marginal error of estimating the deviation from the perpendicularity of the two axes by the proposed method will be determined by the maximum value of the collimation error of theodolite 3 and the errors of ren and parallax of all (three) theodolites:

The description of the proposed method proves the possibility of achieving a technical result - the ability to measure deviations from the perpendicularity of the two axes of rotation of the devices in a non-contact manner.

Claims (2)

1. The method of estimating the deviation from the perpendicularity of the two axes of rotation of the devices, one of which is the leading and the second driven, is implemented by pointing the telescope of the first theodolite operating in the autocollimation mode onto one of the faces of the prism mounted on the driven axis and rotated around the leading axis 90 ° relative to the initial position of the device and obtaining the initial reference of the first angle, characterized in that the telescope of the second theodolite operating in the autocollimation mode is guided to the same face of the prism, which is rotated 180 ° around both axes of the device relative to the previous position, and get the initial count of the second angle, and then provide the optical connection of the first and second theodolites with the third and get the final counts of the first and second theodolites, and the third theodolite get the initial and final readings of the third angle , and the deviation from the perpendicularity of the two axes of the device is estimated from the difference in the sum of the measured three angles and 180 °. 2. The method of evaluating the deviation from the perpendicularity of the two axes of rotation of the devices according to claim 1, characterized in that the measurements are performed in full tricks.