HU189260B - Self-calibrating measuring apparatus for digital measuring features of revolution and angular positions - Google Patents

Abstract

The present invention is a self-authentication measuring device that has multiple design, indicative of the reference angle ési, 2 of the measuring assembly ében, 2, in the proximity of the near uniform discrete angular divisions of the rotary axis, and, if necessary, a signal output unit. The outputs of the multiple-design sensor unit connected to it are connected to the start and stop unit and to the control unit, the output of which is a variable, but with the output of a constant frequency signal during the measurement, the times proportional to the rotation of the rotary axis and the discrete angular divisions and the It is connected to counters that measure time proportional to deviation between φ, 2 reference angles. The measurement results determine the reference angle <p, 2, the discrete angular positions of the rotary axis and its rotational characteristics. Depending on the installation, the measuring device may include extremity selection and display units as well as an evaluation unit. Preferably, the self-authentication measuring device is suitable for rotational movements of variable angular speeds, such as experimental experiments at the intermediate axes of explosive motors and machine tools. -1-

Description

BACKGROUND OF THE INVENTION The present invention relates to a self-calibrating measuring device for the digital measurement of motion characteristics and discrete rotational angles of rotary axes.

Measuring the exact time course of rotational motions with variable angular velocity is an increasingly common task in the experimental testing and diagnosis of various explosive motors and machine tools. Analog and digital measurement methods are known for measuring the rotational inequality of rotation, torsional vibration. The benefits of digital measurement methods can be summarized as follows:

- allow direct measurement in intermediate axle sections, not only at shaft ends,

- Extremely faster and more accurate processing and evaluation of measurement results; digitally stored measurement data can be transferred directly to a computer or measuring equipment including a microprocessor also performs direct processing and evaluation,

- the measuring range is greatly expanded, limited by the lower and upper eigenfrequencies of the analogue measuring instruments; the upper frequency limit also exists for digital measurements, but at a much higher value,

- making measurements simpler and easier to automate.

Most digital torsional vibration measurement methods known and used so far are characterized by the fact that the measurement signals produced by the rotation of discrete angular positions of known value formed in the cross section under study are the carriers of the measurement values. There are two basic variants of measurement methods. In the duration measurement method, the time intervals between known discrete angular positions are measured digitally. (Péter THEISZ-BÖHM, János: Digital torsional vibration measuring device. Hungarian patent number: 157 187, János BÖHM: Experimental investigation of torsional vibrations of shaft wires. Vehicles, Agricultural machinery, Vol. 17, No. 8, 1970 pp. 289-293. , DUNWORTH, A .: Digital Instrumetation for Angular Velocity and Aceeleration IEEE Trans. On Instrumentation and Measurement Vol. IM-18., June 2, 1969. pp. 132-138., WALLINGFORD, E.

E.-WILSON, D.J .: High Resolution Shaft Speed Measurements Using a Microcomputer IEEE Trans. on Instrumentation and Measurement 1977. No. 2 pp. 113-116.) In this case, due to the harmonic components of the rotation of the rotating structure, measurements must be made in the order of hundreds per revolution. In the event counting method, discrete angular turns are obtained by counting discrete angular turns for specific time periods (MEYER, J.P., Tachymétre accélememétre numerique Mesures, Régulation, Automatisme, 1974. No. 1/2, pp. 53-61). In this case, depending on the accuracy of the measurement, 100 times or a thousand times more discrete angular positions have to be created than with the duration measuring method.

The two basic measurement methods have made it possible to develop highly accurate digital measuring instruments. For lower measurement accuracy, such as for controlling limit values, a wise measurement method can be found in British Patent No. 1,482,797 (G 01 P 3/00), where the measurement duration can only vary within a narrow range, and greater measurement coverage is ensured by: during this, the discrete angle range of the measurement is automatically set and is part of the measurement value.

A variant of the duration measuring method is known, in which the rotation of a narrow angle range (slit, double slit) is monitored by a plurality of sensors located outside the rotating axis in a rotational cross section (Kiss József-Solymoss Endre : 162,993 G 01 P 3/36). This method makes it possible to determine the characteristics of rotational motion by measuring the periods of angular rotation Δα in discrete angular positions determined by multiple sensors. Here, too, precise adjustment of the discrete angular positions and the elements defining the angle Δα (shadow mask, light source and sensors) is important. In contrast to the patent specification, however, this method is not free from eccentricity error, while the placement and cost of many sensors are further disadvantages.

Various solutions are known for determining the starting angular positions of measurements. In many sensors, the starting angle position is clearly indicated by the symbol of the selected sensor. If the rotation of the discrete angular positions is monitored by only one sensor, the most common solution is to determine the starting angular position of the measurement cross-section by observing a single discrete angular position in another rotational cross section. Discrete angular positions in the measurement cross-section can also be formed so that the initial angular position can be clearly determined from the signals observed with a single sensor. An interesting solution for purely digital selection independent of speed is described in British Patent No. 1,596,605 (G 01 P 3/00).

Accurate knowledge of discrete angular positions directly affects the accuracy of measurement in all of the measurement variants discussed above. This raises serious problems in two respects. One of these is the complexity and cost of constructing accurate discrete angular positions (accuracy, small size, easy mounting and / or application, time stability). Another problem is the central mounting of the exact measuring disc on the rotating device. Eccentricity causes additional measurement error. Although the effect of this can be mitigated by diametrically located sensors, this further limits the selection of the measurement cross-section, complicates the placement of the sensors, and complicates the measurement and evaluation process.

It is an object of the present invention to overcome these disadvantages of known and applied digital measurement methods. This is made possible by the application of the self-authentication principle, according to which the value of the discrete angular positions and the change of the rotation characteristics can be determined simultaneously with the calibration measurement directly in the measuring arrangement. In this way, discrete angular positions in the measurement cross-section 2189 260 can be formed much simpler and cheaper, and they also need to be accurately measured. However, certain inaccurate adjustments, such as the eccentric positioning and mounting of a precision coulter on the rotary axis, should not, in principle, result in a measurement error when using the self-calibrating measuring method.

Discrete angular positioning unit of the measuring apparatus according to the invention, which emits or applies light, electrical, magnetic, or radioactive signals, or reflects, or which is nearly uniformly distributed, fixed rigidly, independently of the rotary axis, to the axis of the rotating body. it has a multiple signal conductor and preferably a signal output unit, and also a rigid multiple detector, preferably transducing and, if necessary, converting into multiple signals, independently of the axis of rotation, detecting multiple signals arriving by rotation of the axis and discrete angular positions.

The design and placement of the multiple sensor in the measurement cross-section and the multiple signal guide and preferably signal output unit define a reference angle approximately equal to the nearly uniform divisions of the discrete angular positions. In this way, the time-sensitive characteristics of the discrete angular position signals, detected and shaped twice per revolution, will be the bearers of the calibration and measurement values. With the help of these signals, the values of the reference angle and discrete measuring angles, as well as the motion characteristics of the rotary axis (angular velocity, angular acceleration) can be self-calibrated from the numerical values of the duration measurements of a rotation.

Detailed Description of the Invention The present invention will be described in detail with reference to the drawings.

Figure 1 is a schematic diagram of a measuring apparatus according to the invention.

Figures 2 and 3 illustrate one embodiment of units indicating discrete angular positions of the measurement cross-section, with characteristic dividing points.

The time diagrams of Figure 4 show the measurement start signals and the suitably shaped measurement signals of the dual sensors, with the characteristic points, corresponding angular positions, time periods and gauges, corresponding to the respective discrete angular positions.

For self-calibration of rotation characteristics and discrete angular positions of a rotary axis, only 2 units of discrete angular positions measuring or emitting or reflecting light or electrical or magnetic or radioactive signals mounted on or applied to the rotary axis, we use 3 units for starting angle position. The unit 2 is formed in the measuring cross-section A-A of the rotary shaft 1 and the unit 3 is generally formed in the cross-section B-B thereof. In the proximity of the detection of the units 2 and 3, the multiple signal conductor and, if necessary, the signal transmitting unit 4, which is connected with the signal conductors 21 and 22 to the unit 2, the signal conductor to the unit 3 and 24, 25 and signal conductors 26 are connected to unit 5. The unit 5, which senses the signals of the signal conductors 24, 25 and 26, preferably converts them into electrical signals and, if necessary, shapes them, is connected to the unit 6 by the conductor 33 and to the unit 7 by the conductors 32 and 31. The synchronized start-stop unit 6 is connected by line 34 to the unit 7. The unit 7 for controlling synchronously started and stopped measurements is connected by line 35 to units 9 and 10 for counting duration measurements, to which line 36 is connected to a variable unit which produces pulses of variable frequency but fixed over the duration of the measurement. Units 9 measure by counting times for angular turns starting at discrete angular positions of the A-A cross section, and units 10 also count by counting the time intervals corresponding to the discrete angles for the A-A cross-section. Unit 9 is connected by line 41 and unit 10 by line 42 to unit 11 for temporarily storing time measurements, which is connected via line 43 to unit 12, permanently storing measurement results on tape, magnetic tape or otherwise. Thus, in a digital form, all measurement data are available from which the values of the discrete angular positions of the reference angle and the measurement cross-section A-A, as well as the motion characteristics of the rotary axis 1 can be calculated.

The method of generating the measurement information required for self-authentication and accurate measurement of rotation characteristics is described in more detail. In one embodiment, unit 2 outputs signals in substantially uniform divisions, which are transmitted by signal conductors 21 and 24 and 22 and 25 to unit 5, respectively. In a similar embodiment of the unit 3, an agent generating an initial angular position signal is transmitted one turn per turn and transmitted by the signal conductors 23 and 26 to the unit 5. In this embodiment, the unit 4 has a signal conductor role only, which means a direct connection of the signal pair pairs 21-24, 22-25 and 23-26. The function of the unit 3 is only to enable the starting position of the unit 2 to be determined in a manner known per se using the signals of the signal conductors 23 and 26 in accordance with the direction of rotation of the rotary axis 1. All additional measurement information is carried by signals from signal pair pairs 21-24 and 22-25. In another embodiment of the unit 2, it reflects (or absorbs) the units emitted by the unit 4 in a nearly uniform manner, and absorbs it, respectively. signals supplied to the first portion of the signal conductor 22. Equivalent to this is an embodiment of the unit 2, wherein the unit 2 is a measuring disk mounted on the rotary axis 1, which passes (or closes) in a nearly uniform manner the output of the unit 4 and the unit 21 and 21 respectively. signals supplied to the first portion of the signal conductor 22.

The signals reflected or allowed by the unit 2 are shown in Figs. through the second part of the signal conductor 22, they reach the unit 4, which is connected to the terminal 24, respectively. passing them through signal conductor 25 to unit 5. In a similar embodiment of the unit 3, the signal emitted by the unit 4 and applied to the first part of the signal conductor 23 is only reflected or transmitted at the initial angular position, which is transmitted to the second part of the signal conductor 23

189 to 260 units, and thence to signal unit 26 to unit 5. In this embodiment, the unit 4 also has signaling and signaling functions. The signaling role here is the direct connection of the pairs formed by the second part 21 and the second part 24 and the second part 22.

The upper part of Fig. 2 shows the measurement cross-section AA, showing the nearly uniform dividing points P, _F , P _2F , P _{mF of} the units defining the discrete measurement angular positions. The cross-section in terms of circle <p between the dividing points _{IF, <2F} p ... <p _JHF angles and _{2F, 3F,} ... _iF the angles calculated using the starting point P division _1F indicate the drawing. In the lower half of Figure 2, a schematic arrangement of the units 2 and 3 is shown on the extended circumference of the rotary shaft. Located near uniform angular spacing between the two points dividing the unit P _iF P _iK division points. The shaded parts of the figure have the opposite properties (emitting, reflecting or permeating) of units 2 and 3. 2, P; the index of i points is clearly defined. In Fig. 2, the center of the circular measuring cross-section coincides with the point of rotation and intersects at the same point O with 21 and 21, respectively. an edge representing a line of influence of the signal of the signal conductor 22; é2 sensing line, which is 51 and 5 respectively. It leads to 52 batteries. In the figure, beside the direction of rotation indicated by the angular velocity ω of the rotary axis 1, the discrete angular divisions detected by the element 51 are detected by the element 52 after a rotation of φ ₁₂ angular divisions. At the output of the elements 51 and 52 respectively the S31 or wires shown on the wires 32, respectively; S32 signals are carriers of measurement information.

Fig. 3 shows another embodiment of the units 2 and 3 with a circular cross-section, the center of which also coincides with the O point. Referring to Fig. 2, by drawing the outlined mantle, the sensing lines edge and é2 are considered as intersections of the sensing planes Edge and É2 perpendicular to the measurement cross-section, then the same sensing planes can be positioned in Fig. 3 and perpendicular to the measurement live and é2 sensing lines. In this way, the reference angle <p, ₂ represents an angle such that after any angular change, any discrete measurement point of the cross section to be measured moves from element 51 to element 52, producing the same change first in S31 and then in S32. This is well illustrated by the angles φ, _{2 in} the time diagrams of the signals S31 and S32 in Fig. 4.

Figure 4 shows the start and end of the measurement up to 1 revolution, where the measurement is randomly started with the INDV signal in any position, but the synchronized start-stop unit 6 (and unit 7) actually starts the measurement from unit 3 to 23, then transmitted to the unit 5 via the signal conductor 26, and after sensing, if necessary transforming and shaping, the pulse signal S33 transmitted through the line 33 to the unit 6 is realized only at the initial discrete angular division of the unit 2 at the division point P _1K .

If the angles 4 of the points P, _K , P _IF , ... P _mK and P _mF were equal, then the time changes of the signals S31 and S32 would be exactly the same for any alternating rotational motion, only the indexes of the point points shifted by 1 would be worth the two marks. In this case, no self-calibration measurement would be required and rotation characteristics can be measured using methods already known, iii. would be predictable. The essence of the self-validation measurement is that it assumes only the approximate equality of the discrete angular positions, that is, according to Figure 4, the angular _turns of Ó _jF are generally not equal to the reference angle <p, ₂ and the angular deviations Δφ _ιΡ can be arbitrary.

In Figure 4, the symbols S31 and S32 indicate the time periods T to be measured, their N numerical values, and the angles between their respective discrete dividing points. If P _1F , P _2F , ... P _iF ,

... We want to measure the discrete angles of p _mF intersection points by measuring T, ₂ _ _IK , T, ₂ _ _2K , ... T, 2_ _iK , ... T, ₂ _ _mK , and _1F , AT _2F , ... AT _f , ... AT _mF durations. If the period of the very stable pulses delivered from unit 8 to line 36 to unit 9 and unit 10 is T _o , then the time periods T, measured by unit 9, respectively. the relationship between the time periods T measured by 10 units and their measured numerical values is expressed as follows:

T = NT _O , respectively:

ΔΤ = ΔΝ · Τ ₀ .

Assuming that the angles (p _iF) are close to each other and ₂ , ₂ , the constant rotation reference tp _{1 <2} can be determined from the full rotation data, which has the following value in radians:

- 2π ^ ^1,2 m + AK _FK 'where m is the number of divisions and the correction factor ΔΚ _ΡΚ is N and respectively. ΔΝ can be calculated from:

where

N = N

1,2 - (m + 1) K ^1Ν 1,2-1Κ ·

The cross section at the angles of the points of intersection of _1F , _2F , ... _jF , ... _{mF can be inscribed in} the figures 2 and 3:

_IF - 0 / ΔΝ., \ a _2F = a _1F + <p _1F = φ ,, 2 1+ -— \ ^IN 1,2-2K / and generally

In this way, the angle value of the discrete dividing points of the measurement cross-section can be determined from the data of the duration-controlled signal measurements based on the self-authentication principle.

189,260

The values of the rotation characteristics can be calculated from the measured data in several ways. The simplest and most advantageous way to calculate the angular velocity at P _{iF is} the following relationship:

Φΐ, 2 Φΐ, 2

ARC_. = - - —-.

In summary, from the results of the implemented time measurements, the rotational characteristics and the discrete angular positions of the axis can be determined by calculation.

It should be noted here that during the self-authentication measurement, twice as much measurement data should be stored as would be the case for discrete angles of known value. This need for double storage is now only a minor disadvantage, as the technical parameters and prices of digital storage and data storage facilities have been extremely favorable in recent decades.

In another embodiment of the measuring apparatus, unit 9 is connected to line 41 and unit 10 is connected to line 13, which is connected to line 14 by line 44. In this case, the 41, or. the largest and smallest numerical values of the measurement results obtained on the line 42 are selected and stored temporarily by the unit 13 and can then be displayed by the unit 14 at the end of the measurement.

In a further embodiment of the measuring apparatus, unit 11 is connected to unit 15 by line 45 and unit 13 by line 46. In this case, the measurement data can be processed immediately after measurement in the unit 15 and the calculated rotation characteristics (angular velocity, angular acceleration) and discrete angular position values can be stored permanently with 12 units or, if necessary, with 13 units They are displayed.

In another embodiment, unit 16 of the measuring apparatus is connected by line 31 to unit 5, line 34 to unit 6, line 34 to unit 8, and line 47 to unit 14. Thus, following the start signal received from unit 6 through line 34, unit 16 measures the rotational speed of rotary shaft 1 from measurement signals transmitted from unit 5 through line 37 by unit senders S31 through line 31, and then produces the result thereof. transmitted to line 14 via line 47, provides the possibility of indicating speed at the end of the measurement.

It can be proved that the measurement method based on the self-authentication principle can be applied to the "distorted" cases different from the ideal cases shown in Figures 2 and 3. For example, in the case of eccentricity, no additional error occurs when using self-validation measurement [Péter THEISZ: Self-validating digital measurement methods for rotation characteristics and angular positions (dissertation)].

By using the self-validating measurement method, the formation of discrete measurement angular positions in the measured measurement cross-section is considerably simplified, since only the approximation of the angular divisions must be ensured, and not exactly. This, for example, makes the selection of material, design and preparation simpler and less expensive when using a measuring wheel. If necessary, even simpler methods than disc dials can be used to form discrete angles. Significant simplifications and facilitations result from the self-authentication principle of placing units 2, 3 and 4 near the selected measurement cross section.

The additional time measurement data stored in the self-calibrated measurement also allows you to check the correct measurement setting. It is possible that due to uneven rotations and other vibrations the correct setting at the beginning of the measurement will be canceled during the measurement.

These advantageous properties make the self-validating measuring method easy to apply and effective for diagnostic testing of various rotating devices.

Claims (4)

Patent claims 1. A self-calibrating measuring device for the digital measurement of rotation characteristics and discrete angular positions, having a unit (2) applied to or mounted on the rotary axis (1) or emitting light or electric or magnetic or radioactive signals or intermittently reflecting discrete angular positions (2) and a unit (3) of similar construction, but only for the starting angle position, and a signal guide and, if necessary, a signal output unit (4) fixed rigidly independent of the axis of rotation, and a unit for transmitting or intermittently reflecting the signals (2). having discrete angular positions of uniform distribution, characterized in that the signal conductor and, if necessary, the signal transmitting unit (4) are of a multiple configuration such that the reference angle (φ, ₂ ) it defines is equal to the discrete angular divisions; a sensor and preferably an electrical signal converting and forming unit (5), the output of which carries a signal defining the initial angular position of the rotary axis (1) connected to the input of the unit (6) which starts the measurement synchronously and stops one or more complete revolutions. is connected, and on the other hand control unit (7) to an input of proportional to the rotating shaft (1) uneven rotation, as well as determining the signal proportional to the angle difference between the discrete angular positions and the reference angle (φ ₂₎ periods carrier outputs of the control unit (7) of the other two whose outputs are on the enable input of the counter unit (9) for measuring unequal rotation times and on the counter input unit (10) measuring the angular misalignment between discrete angular positions and the reference angle (φ, ₂ ). The counter input is connected to the output of the variable frequency rectangular pulse generating unit (8). Measuring device according to Claim 1, characterized in that the outputs of the counting units (9) and (10) are a unit (13) for selecting and temporarily storing the maximum and minimum measurement values. They are connected to 189 260 turns, the output of which is connected to the input of the data display unit (14). 3. Azl. Measuring device according to claim 1, characterized in that the outputs of the counting units (9) and (10) are connected to an input unit (11) for temporarily storing data, which is connected bidirectionally to the unit (15) processing the data according to the self-authentication method. is connected to the input of a data recording unit (12) for permanently storing results. 4. A measuring device according to any one of claims 1 to 6, characterized in that the other output of the temporary storage unit (11) of the results obtained by processing according to the self-authentication method is connected to the other input of the data selection and temporary storage unit (13).