RU2399915C1 - Angular accelerometre - Google Patents

Abstract

FIELD: physics.

SUBSTANCE: accelerometre has an inertial mass on elastic suspensions, a position sensor, a cover, a base, two permanent magnets, a comparator, a switch and a direct current source. The inertial mass is made from monocrystalline silicon in form of a disc with optical slits and is placed on the elastic suspensions in the gap between the permanent magnets. Current-conducting paths are radially deposited on the surface of the inertial mass, where the beginning and ends of the said paths are connected to each other by deposited current-conducting rings. Each of the rings is connected by current conductors through the elastic suspensions to the output of the switch, whose first input is connected to the direct current source and the second input is connected to the output of the comparator, whose input is connected to outputs of photodetectors, and radiators are connected to the direct current source. The magnets are mounted on the base and cover. The position sensor is made from two radiators and two photodetectors.

EFFECT: invention increases accuracy and widens the frequency range of the measured acceleration.

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Description

The invention relates to measuring technique and can be used to measure angular acceleration, for example in inertial navigation systems.

Known sensor of angular accelerations (patent RU No. 97113215, IPC G01P 15/11, 1999.05.27) containing a stator with a magnetic circuit, made in the form of three concentric rings connected by radial jumpers, and two measuring and one output windings. The rotor is made with two permanent magnets, the poles of the same name directed opposite to each other. One of the magnets is located inside, and the other is outside the magnetic circuit. The measuring windings are each made in the form of two parallel-connected diametrically opposed short-circuited sections wound one on the inner and the other on the outer ring of the magnetic circuit. The output winding is wound on each section of the middle ring of the magnetic circuit.

When angular acceleration acts on the angular acceleration sensor, the rotor begins to rotate around the sensitivity axis, two permanent magnets create a moving magnetic field, as a result an emf is formed on the measuring winding, the magnitude of which determines the value of the measured angular acceleration.

The disadvantages are the small frequency range of the measured input exposure, weight and size characteristics.

The known Accelerometer (patent RU No. 565572, IPC G01P 15/11, 2005.08.20), comprising a housing and two measuring links, each of which includes: inertial mass combined with the sensor rotor, and elastic suspensions. Each of the elastic elements consists of several elastic rods.

The sensitivity axis of the first link coincides with the sensitivity axis of the second. The elastic elements of the suspension of the first link are mirror symmetric to the elastic elements of the second link. The angle sensors of both links are included in the summation and subtraction circuit, the outputs from which form independent channels of angular and linear accelerations, respectively.

When angular acceleration acts on a given sensor, the inertial masses are deflected by the angle measured by the angle sensors. The data on the magnitude of the angles fall on the summation and subtraction scheme, which calculates the magnitude of the angular acceleration.

The disadvantages are weight and size characteristics, a small frequency range of the measured input exposure.

The closest known technical solution is the Angular acceleration sensor (US patent No. 5349858 IPC G01P 15/08, 1994), containing the base, the inertial mass on the elastic suspensions, the second inertial mass on the elastic suspensions, located so that the axis of the suspensions is perpendicular to the axis of the elastic suspensions ring inertial mass and is located inside it, capacitive position sensor.

This sensor has the ability to measure angular acceleration along two axes of sensitivity. When one of the axes of sensitivity of angular acceleration acts on the sensor, the inertial mass rotates at a certain angle around the axis of the elastic suspensions. As a result, the distance between the plates of the capacitive position sensor changes, as a result, and the capacitance of the capacitor of the capacitive sensor changes. By changing this capacity, measured acceleration is judged.

The disadvantages are the low accuracy of the measurement, the small frequency range of the measured impact.

The task is to create an angular accelerometer that measures angular acceleration with greater accuracy and an extended frequency range.

The technical result is to increase accuracy and expand the frequency range of the measured acceleration.

The technical result is achieved by the fact that two permanent magnets, a comparator, a key and a direct current source are introduced into an angular accelerometer containing an inertial mass on elastic suspensions, a position sensor, a cover and a base, the inertial mass is made of single-crystal silicon in the form of a disk with optical slits and placed on elastic suspensions in the gap between the permanent magnets with the possibility of angular movement, the magnets are fixed on the base and the cover, the position sensor is made of two emitters and two photodetectors s, the optical axes of which pass through the optical slots and are fixed in the holes on the base and the lid, conductive tracks are radially sprayed on the surface of the inertial mass, the beginnings and ends of which are interconnected by sprayed conductive rings and each of the rings is connected by current conductors to the outputs of the key through elastic suspensions, to the first input of which a DC source is connected, and the output of a comparator is connected to the second input, the outputs of photodetectors are connected to its input, and the emitters are connected to the source nick DC.

The technical result is achieved due to the fact that the inertial mass self-oscillates around the axis of sensitivity under the action of an alternating DC signal generated in the feedback circuit. In this case, the presence of the input action leads to a shift in the center of oscillations and the appearance of temporary modulation of the signal.

The set of essential features of the invention ensures the achievement of the technical result achieved by the invention due to the fact that the inertial mass, elastic suspensions, permanent magnets, optical slots, base, cover, emitters, photodetectors, conductive tracks, key, direct current source contained in the claimed device The comparator can be effectively used to measure angular acceleration.

The analysis of the prior art conducted by the applicant has established that there are no analogues characterized by sets of features identical to all the features of the claimed angular accelerometer, therefore, the claimed invention meets the condition of "novelty."

Search results for known technical solutions in this and related fields of technology in order to identify features that match the distinctive features of the claimed invention from the prototypes showed that they do not follow explicitly from the prior art.

From the prior art determined by the applicant, the influence of the transformations provided for by the essential features of the claimed invention on the achievement of the specified technical result has not been revealed, therefore, the claimed invention corresponds to the "inventive step".

The invention is illustrated by drawings, where figure 1 shows the electro-kinematic diagram of the sensor and the following notation:

1. Inertial mass

2. Elastic suspensions

3. Permanent magnets

4. Optical slit 1st

5. Optical slit 2nd

6. The basis

7. Cover

8. Emitter 1st

9. Emitter 2nd

10. Photodetector 1st

11. Photodetector 2nd

12. Current paths

13. Conductive rings

14. Conductors

15. The key

16. DC source

17. Comparator

On figa presents a signal at the output of the key in the absence of external influences.

On figb presents the signal at the output of the key in the presence of external influences.

In the proposed angular accelerometer, the inertial mass 1 is placed on elastic suspensions 2 in the gap between the permanent magnets 3 with the possibility of angular movement and is made of single-crystal silicon in the form of a disk with optical slots 4, 5, magnets 3 are mounted on the base 6 and cover 7, the position sensor is made of two emitters 8, 9 and two photodetectors 10, 11, the optical axis of which pass through the optical slots 4, 5 and are fixed in the holes on the base 6 and cover 7, conductive radially sprayed on the surface of the inertial mass 1 track 12, the beginning and ends of which are interconnected by sprayed conductive rings 13 and each of the rings by current conductors 14 through elastic suspensions 2 are connected to the outputs of the key 15, to the first input of which a DC source 16 is connected, and the output of the comparator 17 is connected to the second input, to the input of which the outputs of the photodetectors 10, 11 are connected, and the emitters 8, 9 are connected to a direct current source 16.

The comparator 17 can be performed, for example, based on a commercially available microchip (comparator) 521CA2. The key 15 can be performed, for example, on the basis of a commercially available transistor GT108.

The DC source 16 can be represented by any typical circuit that meets the specified parameters of the power supply of the conductive tracks 12.

The sensor operates as follows.

The sensor is mounted on an object for measuring angular acceleration, taking into account the fact that the axis of sensitivity passes through the center of the disk of inertial mass 1 on elastic suspensions 2 perpendicular to its surface. In the initial state, the first emitter 8 is closed by the first optical slit 4, the second emitter 9 is open. As a result, a signal appears at the output of the 2nd photodetector 11, which causes the comparator 17. The output voltage of the comparator 17 controls a key 15, which connects the DC source 16 to the conductive paths 12 through the conductive rings 13 and conductors 14. As a result of the creation of a magnetic field conductive paths 12 and its interaction with the magnetic field of permanent magnets 3 there is a pair of forces that creates a moment acting on the disk of inertial mass 1, which, in turn, is rotated by some angle, while the first emitter 8 is open, and the second emitter 9 is closed by the second optical slit 5.

As a result, a signal appears at the output of the first photodetector 10, and disappears at the output of the second photodetector 11. Because the signal of the first photodetector 10 goes to the comparator 17, it is activated, its output voltage controls the key 15, this leads to switching the key 15 of the current direction in the tracks 12 on the surface of the disk of inertial mass 1. Next, the switching process is repeated and, therefore, the disk of inertial mass 1 makes self-oscillations. The use of the key 15 and the direct current source 16 allows you to form the output current of the key 15 rectangular current pulses, constant in current strength and frequency, and hence self-oscillations, constant in amplitude and frequency. The signal at the output of the key circuit is shown in figa. When exposed to an angular acceleration sensor, it works as follows. If there is acceleration along the axis of sensitivity of the sensor, an additional torque will act on the sensitive mass 1. As a result, with the angular movement of the disk of inertial mass after switching by the comparator 17 of the key 15, the time of movement of the disk 1 to the point of overlap of the second emitter 9 and the opening of the first will increase due to the fact that the moment will act on the disk:

M = Mkp-Mvneshn,

where M is the total torque acting on the inertial mass, Mkp is the moment created by the interaction force of the current in the tracks and with the permanent magnet field, MV is the additional torque acting on the inertial mass.

As a result, this leads to a decrease in turn time. As a result, these phenomena will lead to a change in the duration of the rectangular pulses at the output of the key 15 (fig.2b). The change in the duration of the rectangular pulses judges the measured acceleration. Improving the accuracy of measurements is achieved by introducing a mode of self-oscillations and reducing as a result of this harmful moments acting on the inertial mass 1.

Thus, the above information proves that when implementing the claimed invention, the following conditions are met:

- a tool embodying the proposed device in its implementation, is intended for use in measuring equipment, namely in angular accelerometers for measuring angular acceleration, for example in inertial navigation systems;

- for the claimed invention as described in the independent claim, the possibility of its implementation using the means described before the filing date of the application has been confirmed;

- a tool embodying the claimed invention in its implementation, is able to provide the specified technical result.

Therefore, the claimed invention meets the condition of patentability "industrial applicability".

Claims (1)

An angular accelerometer containing an inertial mass on elastic suspensions, a position sensor, a base and a cover, characterized in that two permanent magnets, a comparator, a key and a direct current source are additionally introduced into the device, the inertial mass is made of single-crystal silicon in the form of a disk with optical slits and placed in the gap between the permanent magnets with the possibility of angular movement, the magnets are fixed on the base and the cover, the position sensor is made of two emitters and two photodetectors, optical si which pass through optical slots and are fixed in the holes on the base and the cover, conductive tracks are radially sprayed on the surface of the inertial mass, the beginnings and ends of which are interconnected by sprayed conductive rings and each of the rings by current conductors is connected through the elastic suspensions to the outputs of the key, to the first input which is connected to a direct current source, and the output of a comparator is connected to the second input, to the input of which the outputs of photodetectors are connected, and the emitters are connected to a constant source of current.

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