RU2278389C2 - Device for measuring angular acceleration of shift - Google Patents

Abstract

FIELD: measurement technology.

SUBSTANCE: device can be used for measurement of parameters of rotation of shaft of automatic control systems. Measuring device is built on the base of cylindrical magnet domains and microelectronic devices. Ferromagnetic disc with film of single-axis magnetization has two cylindrical magnetic domains spaced for angle of φ_1. The cylindrical ferromagnetic domains rotate due to domain-shifting structures coaxial to shaft at angular velocity of ω_D. Cylindrical ferromagnetic domain detectors D1 and D2 are tightly connected with shaft; detectors are spaced by angle of φ_c. Angular acceleration is found from relation of E=C*(1/t₂-1/t₂), where E is angular acceleration of shaft, C is angular velocity of domain ω_D, t₁ is time during which cylindrical magnetic domain 1 moves along detectors D₁ and D₂, t₂ is time during which cylindrical magnetic domain 2 moves between detector D₁ and D₂. Values of t1 and t2 are found by means of pulse oscillator, pulse counter. Division and subtraction operations are preformed by means of divider and subtraction unit. Cylindrical magnetic domains have small sizes and high speed of movement.

EFFECT: improved precision of measurement: high speed of operation.

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Description

The present invention relates to the field of measuring the parameters of rotation of the shaft. The invention can be used in automatic control systems, in industrial control systems, in the measurement technique, in acceleration measuring devices.

A known converter of angular acceleration of the shaft into a code based on the use of phase shifters [a.s. No. 1994990], described in the book of VG Domrachev et al. “Circuitry of digital converters”, M., Energoizdat, 1987. The essence of this device is that when the shaft is rotated using a pulse generator and a phase shifter, phase shifts of pulses are created, which are fed to a phase detector with a controlled generator, which is controlled by an adder with an integrator, and the other output of the phase detector through a low-pass filter produces a signal corresponding to angular acceleration.

The disadvantage of this device is the low accuracy, low speed and large dimensions due to the great complexity of the conversion and use of phase shifters (rotary transformers, etc.).

Known Converter angular acceleration [and.with. 1101740 USSR] using phase shifters and electric frequency reduction, due to which the error is reduced. But still large dimensions, margin of error and little speed. The device is even more complicated.

The closest in technical essence to the claimed object is the angular acceleration converter to the code described in the book (V. G. Domracheva et al. “Circuit design of digital converters”, M., Energoizdat, 1987, p. 145).

The essence of this device is that the generator feeds the phase shifter through the frequency divider and the reference voltage driver, the shaft of which transmits information about angular acceleration. The signal from the output of the phase shifter is fed to the null-organ and then to the trigger, from the output of which to the narrow pulse shaper, to the first accumulating adder and to the first input of the register for generating the output signal of angular acceleration. The signal from the narrow pulse shaper is fed to the second accumulating adder and the information input of the binary totalizing counter, the output of which is fed to the binary adder, the second input of which is the output signal of the second accumulating adder, from the output of the binary accumulating adder the signal is supplied to the second register acceleration.

The disadvantages of this device are the low speed associated with the use of the phase as an intermediate parameter in the converter, the low accuracy associated with the error of the phase shifter itself, the large size and complexity of the conversion.

The objective of the invention is the creation of a meter of angular acceleration of the shaft, which allows to increase the conversion accuracy, speed, significantly simplify the conversion and reduce the size. This is achieved by using the high-speed properties of cylindrical magnetic domains (CMD) and design features of the implementation of circuit solutions.

The essence of the invention is to create cylindrical magnetic domains on a ferromagnetic disk with a magnetically uniaxial ferromagnet film that rotate around the shaft with a speed ω _d determined by the rotation speed of the external magnetic field vector ω _vp , which is significantly higher than the shaft speed. The CMD microelectronic detectors detect them and allow measuring the time intervals of the passage of the CMD between two detectors. The reciprocal values of the values of these intervals determine the values of angular accelerations according to the formula (in accordance with the authors patent No. 2137296 of 09/10/99, "Method of measuring the angular acceleration of the shaft"):

E = C · (1 / t ₂ -1 / t ₁ ),

where E is the angular acceleration of the shaft;

C is the angular velocity of the domain ω _d ;

t ₁ - time progress CMD1 between the detectors CMD D1 and D2;

t ₂ - time progress CMD2 between detectors CMD D1 and D2.

The technical result is achieved due to the lack of analog converters, the simplicity of the device, the use of CMD technology and microelectronic technology.

The possibility of carrying out the invention is confirmed by the fact that the authors have already developed and protected by copyright certificates angle and speed transducers, built on the basis of CMD technology and microelectronic technology. The possibility of measuring angular displacements with an accuracy of one angular second and linear to one micrometer, as well as time intervals up to fractions of a microsecond, is proved. All this makes it possible to measure accelerations with a simple method.

The diagram of the angular acceleration meter in the code is shown in the drawing.

It contains the following elements: shaft (1), ferromagnetic disk ФД (2), ЦМД1 (3), ЦМД2 (4), detectors Д1 (5) and Д2 (6), domain-promoting structures of DPS (7), brackets К1 ( 8) and K2 (9), UVP rotating magnetic field assembly (10), generator G (11), delay element (12), triggers T1 (13) and T2 (14), pulse counter ST (15), divider (16), the registers RG1 (17) and RG2 (18), the subtractor “-∑” (19), the bus “output” (20) and the synchronization bus (21).

CMD1 (3) and CMD2 (4) are located on the PD (2), rigidly connected to the fixed part of the meter, and CMD detectors D1 (5) and D2 (6) on the brackets K1 (8) and K2 (9), rigidly connected to meter shaft. The trajectory along which the CMD moves is determined by the DPS (7), which is located on a circle concentric with respect to the shaft. The output of the detector D1 (5) is connected to the input 1 of the counter ST (15) and through the element "Delay" (12) with the input 1 of the trigger T1 (13). The output of detector D2 (6) is connected to input 2 of trigger T1 (13) and input 2 of the divider “1 / N” (16), input 1 of which is connected to the output of counter ST (15). The output 1 of the divider is connected to input 1 of RG1 (17) and input 1 of the subtractor (19). Input 2 of the subtractor (19) is connected to the output of the register RG1 (17), and output 2 through the register RG2 (18) is connected to the output bus (20). The output 1 of the subtractor (19) is connected to the input 1 of the register RG2 (18), with the synchronization bus (21) and the input 2 of the trigger T2 (14). Input 1 of trigger T2 (14) is connected to the output 2 of the divider (16), and its outputs are connected, respectively, 2 to input 2 of RG1 (17), 1 to input 3 of the subtractor (19). The output of the generator (11) is connected to the UVP (10) and to the input 3 of the counter ST (15), the input 2 of which is connected to the output of the trigger T1 (13).

The angular acceleration meter works as follows.

On the ferromagnetic disk, rigidly connected with the fixed part of the meter, created CMD1 and CMD2, located on the circumference of the concentric axis of the shaft. The angular distance between the CMD is constant and equal to the angle φ ₁ , and the angle between the detectors is equal to φ _s . After the device is turned on, under the action of domain-promoting structures controlled by a rotating electromagnetic field (see the book by V.P. Milovzorov. Electromagnetic devices of automation. M., Higher School, 1983, pp. 239-321), the CMD move along circle relative to the shaft with a speed that is significantly higher than the maximum speed of rotation of the shaft. Moreover, they rotate relative to the CMD detectors, which are rigidly connected to the shaft.

When the first CMD1 passes near the detector D1, the last generates a current pulse, which resets the counter ST (15) to zero and then through the “delay” element (12) to input 1 of trigger T1 (13), the output of which acts on input 2 of the counter ST (15), revealing through its input 3 the following of the generator pulses into the counter. The counting of pulses begins, determining the time t _{1 of the} passage of the CMD between the detectors.

Continuing movement, CMD1 reaches the second detector D2, which gives a current pulse. This pulse is fed to input 2 of the trigger T1 (13) and stops the supply of pulses from the generator G (11) to the conversion circuit. The number of pulses counted by the counter ST (15) determines the time t ₁ . The pulse from D2 acts on the divider (16), opening the signal input (t ₁ ) from the counter output to the divider.

The divider performs the 1 / N division operation (where N = t ₁ ) and outputs the result to input 1 of register RG1 (17) and to input 1 of the subtractor (19). The output 2 of the divider (16) acts on the counting input 1 of the trigger T2 (14), the output 2 of which acts on the input 2 of the register RG1 (17), and it gives information (1 / t ₁ ) to the input 2 of the subtractor (19). Further, when CMD2 reaches detector D1, a pulse appears at its output. After that, the signal is processed similarly to the signal from CMD1. As a result, a signal appears at the second input in the form of the subtractor code N2 (N2 = 1 / t ₂ ) and a subtraction operation is performed, after which the code corresponding to the acceleration is fed to the output register, and the signal from the second output of the subtractor allows the output of information about the angular acceleration to the output bus, translates the trigger T2 (14) to its original position and generates a synchronization signal (21).

Thus, simultaneously with the synchronization signal on the bus (20), the angular acceleration value calculated by the above formula is set.

Information sources

a) V.P. Milovzorov. Electromagnetic automation devices. M., "Higher School", 1983, pp. 293-321.

b) Bobeck A.H. Properties and device applications of magnetic domains iorthoferrities // Bell System Techn.J. - 1967 - 46 No. 10 - b. 1901-1925.

c) V.S. Podlipensky, V.H. Petrenko. Electromagnetic and electric machine automation devices. Kiev. The head publishing house of the Vishka Shkola Publishing Association. 1987. p. 209-227.

d) T. O'Dell. Ferromagnetodynamics. Dynamics of CMD, domains and domain walls. M., "World". 1983.

d) G.I.Katenko. Magnetoresistors ed. "Energy", Leningrad branch, 1972.

f) V.G. Baryakhtar, Yu.I. Gorobets. Cylindrical magnetic domains and their lattices. Kiev, Naukova Dumka, 1988

Claims (1)

A shaft angular acceleration meter, comprising a shaft, a generator, a first trigger, a first register, a frequency divider, characterized in that a magnetically uniaxial ferromagnetic disk is inserted in it, rigidly connected to the fixed part of the meter, a rotating magnetic field assembly, a domain-promoting structure on a ferromagnetic disk, which is located on a concentric circle with respect to the shaft, the first and second cylindrical magnetic domains located on the path of the domain-promoting structure, the first and second cylinder detectors of magnetic magnetic domains on brackets rigidly connected to the shaft, a pulse counter, a second trigger, a second register, a subtractor, an output bus, a synchronization bus and a delay element, the input of which is connected to the first detector of cylindrical magnetic domains and the first input of the pulse counter, and the output - with the first input of the first trigger, the second input of which is connected to the second detector of the CMD and the second input of the divider, the first input of which is connected to the output of the counter, and the first output - with the first input of the subtractor and through the first register from the second input of the subtractor, the second output of which is connected to the second input of the second register, the output of which is connected to the "output" bus, and the first input - with the first output of the subtractor, with the synchronization bus and with the second input of the second trigger, the second and first outputs of which are connected respectively to the second input of the first register and the third input of the subtractor, and the first input to the second output of the divider, and the output of the generator is connected to the node of the rotating magnetic field and to the third input of the counter, the second input of which is connected to the output of the first of the trigger.