RU2410701C1 - Micromechanical sensor of angular speed - Google Patents

Abstract

FIELD: measurement equipment. ^ SUBSTANCE: invention relates to measurement equipment, and may be used to measure angular speed, for instance, in inertial navigation systems. Micromechanical sensor of angular speed comprises base and cover, bearing frame, the first and second inertial masses fixed on elastic elements of suspension, sensors of position of each inertial mass. At the same time additionally second position sensors are introduced for each inertial mass, as well as permanent magnets, the first and second comparators, the first and second keys and source of DC, inertial masses are made of single-crystal silicon in the form of plates with rectangular optical slot each and are fixed in bearing frame with the possibility of displacement along two mutually perpendicular longitudinal and transverse axes in plane, which is parallel to base, inertial masses are arranged in gap between permanent magnets, on surface of each inertial mass, parallel to transverse axis, there are current-conducting paths sputtered. ^ EFFECT: increased sensitivity and expansion of measurements range. ^ 2 dwg

Description

The invention relates to the field of instrumentation, in particular to measuring equipment, and can be used to measure angular velocity, for example, in various control systems, navigation, stabilization and guidance.

Known sensor angular velocity Mars-RR (Micromachined Angular Rate Sensor) [Geiger W. et al. A Silicon Rate Gyroscope with Decoupled Driving and Sensing Mechanisms MARS-RR. - Symposium Gyro Technology, Germany. - 1998], containing an inertial mass fixed on the elastic elements of the suspension relative to the anchors fastened to the substrate. The elastic suspension elements allow the inertial mass to move along one axis and together with the supporting frame along the second axis. Electrostatic force sensors provide movement of the sensor element of the position sensor together with the supporting frame and rotor elements of the force sensor.

The disadvantages are the low value of the force created by electrostatic comb engines, low accuracy and a small measurement range.

Known angular velocity sensor Micromachined Comb Drive Tuning Fork Gyroscope [United States Patent 5496436], containing the first and second inertial mass associated with the supporting frame by means of rod elastic suspension elements. The supporting frame is connected to the base through elastic suspension elements that provide angular movement. An electrostatic force sensor excites out-of-phase primary translational oscillations.

Under the influence of the angular velocity of the base, the Coriolis forces create a variable moment, leading to secondary angular vibrations of the frame. Angular oscillations are measured by capacitive sensors, the electrodes of which are located under the first and second inertial masses.

The disadvantages are the low value of the force generated by electrostatic comb engines, low accuracy and a small measurement range due to the use of amplitude modulation of the signal.

The closest known technical solution is the angular velocity sensor ADXRS 300 [Geen J. US Patent No. 5635640 Micromachined device with rotationally vibrated masses. - June 3, 1997], containing a base and a cover, the first and second inertial masses mounted on the elastic elements of the suspension, plates for forming an electrostatic feedback loop and implementing a compensation mode. The first and second inertial masses are driven by three electrostatic comb engines in vibrational motion parallel to the base plane so that the inertial mass oscillations have opposite phases.

In the presence of angular velocity under the action of the Coriolis force, one inertial mass will rise and the other will fall with respect to the plane of vibration. Sensitive elements of the capacitive position sensor form the output signal of the angular velocity sensor.

The disadvantages are the low value of the force generated by electrostatic comb engines, low accuracy and a small measurement range due to the use of amplitude modulation of the signal.

The objective is to create an angular velocity sensor that measures angular velocities with greater accuracy and an extended frequency range.

The technical result is to increase the accuracy and sensitivity of measuring angular velocity, expanding the range of measurements.

The technical result is achieved by the fact that in the micromechanical angular velocity sensor containing a base and a lid supporting the frame, the first and second inertial masses mounted on the elastic elements of the suspension, the position sensors of each inertial mass, additionally introduced the second position sensors of each inertial mass, permanent magnets, the first and second comparators, the first and second keys and a direct current source, inertial masses are made of single-crystal silicon in the form of plates with a rectangular optical slit giving and fixed in the supporting frame with the ability to move along two mutually perpendicular longitudinal and transverse axes in a plane parallel to the base, inertial masses are placed in the gap between the permanent magnets, the first position sensors of each inertial mass are made in the form of a pair consisting of a radiator and a two-segment photodetector, the optical axes of which pass through the optical slits, the second position sensors are made in the form of a pair consisting of an emitter and a photodetector, the luminous flux of which is modulated by m plates, emitters and photodetectors of both position sensors of each plate are fixed in the holes on the base and cover, respectively, with the possibility of fixing by the first sensor the displacement of the inertial mass along the longitudinal axis, and the second sensor on the transverse axis, on the surface of each inertial mass, parallel to the transverse axis conductive tracks are sprayed, the beginnings and ends of which are interconnected by conductive buses, each of which is connected through current-carrying elements of the suspension of the first inertial mass s with the output of the first key, to the first input of which a DC source is connected, and the output of the first comparator is connected to the second input, the output of one segment of the photodetector of the first sensor is connected to the first input, and the output of the second segment is connected to the second input, and from the output of the second the position sensor of the first inertial mass, the output signal is taken, the emitters of the position sensors of the first inertial mass are connected to a constant current source, the conductive buses of the second inertial mass of the current lead the water through the elastic suspension elements of the second inertial mass is connected to the output of the second key, to the first input of which a DC source is connected, and the output of the second comparator is connected to the second input, the output of one segment of the photodetector of the second sensor is connected to the first input, and the output is connected to the second input the second segment of the photodetector of the second sensor, the emitters of the sensors of the position of the second inertial mass are connected to a constant current source.

The technical result is achieved due to the fact that the first and second inertial masses self-oscillate 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 analysis of the prior art by the applicant has established that there are no analogs characterized by sets of features identical to all the features of the claimed micromechanical angular velocity sensor, 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 indicated technical result was not 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. The first inertial mass.

2. The second inertial mass.

3. The first elastic elements of the suspension.

4. The second elastic elements of the suspension.

5. The supporting frame.

6. Permanent magnets.

7. The basis.

8. The first optical slit.

9. The second optical slit.

10. The cover.

11. The first emitter.

12. The second emitter.

13. The first two-segment photodetector.

14. The second two-segment photodetector.

15. The third emitter.

16. The fourth emitter.

17. The first photodetector.

18. The second photodetector.

19. The first conductive paths.

20. The second conductive paths.

21. The first conductive bus.

22. The second conductive bus.

23. The third conductive bus.

24. The fourth conductive bus.

25. The first current lead.

26. The second current lead.

27. The first key.

28. The source of direct current.

29. The first comparator.

30. The third current lead.

31. The fourth current lead.

32. The second key.

33. The second comparator.

On figa presents a signal at the output of the first and second keys 27 32 in the absence of acceleration along the longitudinal axis.

On figb presents the signal at the output of the first and second keys 27 and 32 in the presence of acceleration along the longitudinal axis.

In the proposed micromechanical angular velocity sensor, the first and second inertial masses 1, 2 are placed on the elastic suspension elements 3, 4 in the carrier frame 5 in the gap between two permanent magnets 6 with the possibility of linear movement along two mutually perpendicular longitudinal and transverse axes in a plane parallel to the base 7, and is made of single-crystal silicon in the form of a plate with rectangular optical slots 8, 9. Magnets 6 are mounted on the base 7 and the cover 10. The first position sensors of each inertial mass 1, 2 flaxen in the form of pairs consisting of emitters 11, 12 and two-segment photodetectors 13, 14, the optical axis of which pass through the optical slots 8, 9, emitters 11, 12 and two-segment photodetectors 13, 14 are fixed to the base 7 and the cover 10. Second position sensors made in the form of pairs consisting of emitters 15.16 and photodetectors 17, 18, the optical axis of which pass near the edge of the inertial masses 1, 2. Emitters 11, 12, 15, 16 and photodetectors 13, 14, 17, 18 of both position sensors each inertial mass 1, 2 are fixed in the holes on the base 7 and the cover 10, with tvetstvenno. On the surface of each inertial mass 1, 2 parallel to the transverse axis are sprayed conductive tracks 19, 20, the beginnings of which are interconnected by conductive tires 21, 22, and the ends are connected by conductive tires 23, 24. Conductive tires 21, 23 by current leads 25, 26 through elastic elements the suspension 3 of the first inertial mass 1 is connected to the output of the key 27, to the first input of which a DC source 28 is connected, and the output of the first comparator 29 is connected to the second input, the output of one segment of the two-segment is connected to its first input photodetector 13 of the first sensor, and the output of the second segment is connected to the second input. The emitters 11, 15 of the position sensors of the first inertial mass 1 are connected to a constant current source 28, the conductive busbars 22, 24 of the second inertial mass 2 by current leads 30, 31 through the elastic suspension elements 4 of the second inertial mass 2 are connected to the output of the second key 32, to the first input of which a DC source 28 is connected, and the output of the second comparator 33 is connected to the second input, the output of one segment of the two-segment photodetector 14 of the second sensor is connected to the first input, and the output of the second is connected to the second input egmenta two-segment photodetector 14, a second sensor radiators 12, position sensor 16 of the second inertial mass 2 is connected to a DC source 28.

The emitters 11, 12, 15, 16 can be made, for example, based on commercially available KIPD80 V.

Photodetectors 17, 18 can be made, for example, based on mass-produced MG-32 photodetectors.

Two-segment photodetectors 13, 14 can be made, for example, based on commercially available optocouplers VO0630T [Password N.V., Kaydalov S.A. Photosensitive devices and their application: Handbook. M: Radio and communication, 1991].

Comparators 29, 33 can be performed, for example, on the basis of a commercially available microcircuit (comparator) 521CA2.

The keys 27, 32 can be performed, for example, on the basis of the commercially available transistor GT108.

The direct current source 28 can be represented by any typical circuit that meets the specified parameters of the power supply of conductive paths 19, 20. [Reference to the elements of electronic devices. Ed. V.N.Dulina, M.S. Zhuka. M: Energy, 1977].

The micromechanical angular velocity sensor operates as follows:

и взаимодействия этого магнитного поля с магнитным полем постоянных магнитов 6, имеющим индукцию

, возникает сила

, действующая на инерционную массу 1 по продольной оси и равнаяA micromechanical angular velocity sensor is mounted on an object for measuring angular velocity, taking into account that the sensitivity axis is orthogonal to the plane of the base 7 and passes through its center. In the initial state, the first emitter 11 through the first optical slot 8 is open for the first segment of the first two-segment photodetector 13, and for the second segment it is closed. As a result, a signal appears at the output of the first segment of this two-segment photodetector, which is sent to the first input of the first comparator 29, the output voltage of which controls the first switch 27, which connects the DC source 28 to the first conductive tracks 19 through the first and third conductive buses 21, 23 , the first and second current leads 25, 26. As a result of the creation of a magnetic field k conductive paths 19 having a length l, when applying electric current to them

and the interaction of this magnetic field with a magnetic field of permanent magnets 6 having induction

, there is a force

acting on the inertial mass 1 along the longitudinal axis and equal to

.

.

перемещается по продольной оси, при этом первый излучатель 11 через первую оптическую щель 8 становится открыт для второго сегмента первого двухсегментного фотоприемника 13 и закрыт для первого его сегмента. Вследствие этого с выхода первого сегмента этого двухсегментного фотоприемника сигнал поступать перестает, а на выходе второго его сегмента появляется сигнал. Этот сигнал направляется на второй вход первого компаратора 29, выходной сигнал которого направляется на первый ключ 27, что приводит к переключению им направления тока в токопроводящих дорожках 19. Далее процесс переключения повторяется, и инерционная масса 1 совершает автоколебания по продольной оси.Inertial mass 1 by force

moves along the longitudinal axis, while the first emitter 11 through the first optical slot 8 becomes open to the second segment of the first two-segment photodetector 13 and is closed to its first segment. As a result, the signal stops coming from the output of the first segment of this two-segment photodetector, and a signal appears at the output of its second segment. This signal is sent to the second input of the first comparator 29, the output signal of which is sent to the first key 27, which leads to the switching of the current direction in the conductive tracks 19. Then, the switching process is repeated, and the inertial mass 1 self-oscillates along the longitudinal axis.

In the initial state, the second emitter 12 through the second optical slot 9 is open for the first segment of the second two-segment photodetector 14, and for the second segment it is closed. As a result, a signal appears at the output of the first segment of this two-segment photodetector, which is sent to the first input of the second comparator 33, the output voltage of which controls the second switch 32, which connects the DC source 28 to the second conductive tracks 20 through the second and fourth conductive buses 22, 24 , the third and fourth current leads 30, 31. The inertial mass 2 moves along the longitudinal axis, while the second emitter 12 through the second optical slot 9 becomes open for the second segment of the second uhsegmentnogo photodetector 14 and closed to its first segment. As a result, the signal stops coming from the output of the first segment of this two-segment photodetector, and a signal appears at the output of its second segment. This signal is sent to the second input of the second comparator 33, the output signal of which is sent to the second key 32, which leads to the switch of the current direction in the conductive paths 19. Then, the switching process is repeated, and the inertial mass 2 self-oscillates along the longitudinal axis in antiphase from the first inertial mass 1.

по оси чувствительности датчика на первую инерционную массу 1, движущуюся по продольной оси со скоростью

и имеющую массу m, по поперечной оси действует сила

равнаяWhen exposed to a micromechanical angular velocity sensor, it works as follows. In the presence of angular velocity

along the axis of sensitivity of the sensor to the first inertial mass 1, moving along the longitudinal axis with speed

and having mass m, a force acts along the transverse axis

equal

первая инерционная масса 1 совершает автоколебания по поперечной оси, при этом световой поток третьего излучателя 15, поступающий на первый фотоприемник 17, модулируется краем первой инерционной массы 1. Выходной сигнал первого фотоприемника 17 несет информацию об угловой скорости вращения микромеханического датчика угловой скорости

.Due to the action of force

the first inertial mass 1 self-oscillates along the transverse axis, while the light flux of the third emitter 15 arriving at the first photodetector 17 is modulated by the edge of the first inertial mass 1. The output signal of the first photodetector 17 carries information about the angular velocity of rotation of the micromechanical angular velocity sensor

.

по оси чувствительности датчика вторая инерционная масса 2 совершает автоколебания по поперечной оси в противофазе с первой инерционной массой 1, при этом световой поток четвертого излучателя 16, поступающий на второй фотоприемник 18, модулируется краем второй инерционной массы 2. Выходной сигнал второго фотоприемника 18 несет информацию об угловой скорости вращения микромеханического датчика угловой скорости

.In the presence of angular velocity

along the sensitivity axis of the sensor, the second inertial mass 2 self-oscillates along the transverse axis in antiphase with the first inertial mass 1, while the light flux of the fourth emitter 16 entering the second photodetector 18 is modulated by the edge of the second inertial mass 2. The output signal of the second photodetector 18 carries information about the angular velocity of rotation of the micromechanical angular velocity sensor

.

An additional advantage of the micromechanical angular velocity sensor is the ability to measure acceleration along the longitudinal axis. When exposed to a micromechanical acceleration sensor along the longitudinal axis, the inertial mass will act on the first inertial mass 1 along the longitudinal axis. This leads to a shift of the center of oscillation of the first inertial mass 1. As a result, these phenomena will lead to a change in the duration of the rectangular pulses at the output of the first key 27 (Fig.2b). Similarly, but in antiphase, the center of oscillation of the second inertial mass 2 will shift, which will lead to a change in the duration of the rectangular pulses at the output of the second key 32.

By changing the duration of the rectangular pulses at the output of the first and second keys 27 and 32, it is possible to determine the measured acceleration along the longitudinal axis.

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 first and second inertial masses 1 and 2.

The set of essential features of the invention ensures the achievement of a technical result in the implementation of the invention due to the fact that the base and cover contained in the claimed device, the supporting frame, the first and second inertial masses with rectangular optical slots and conductive tracks, elastic suspension elements, the first and second position sensors of each inertial mass, two permanent magnets, first and second keys, first and second comparators, a direct current source can be effectively used for For measuring angular velocity.

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 in the form 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)

A micromechanical angular velocity sensor containing a base and a lid supporting the frame, the first and second inertial masses mounted on the elastic elements of the suspension, the position sensors of each inertial mass, characterized in that the second position sensors of each inertial mass, permanent magnets, the first and second are introduced comparators, the first and second switches and a direct current source, inertial masses are made of single-crystal silicon in the form of plates with a rectangular optical slit each and are fixed in the carrier a common frame with the ability to move along two mutually perpendicular longitudinal and transverse axes in a plane parallel to the base, inertial masses are placed in the gap between the permanent magnets, the first position sensors of each inertial mass are made in the form of a pair consisting of a radiator and a two-segment photodetector, the optical axes of which pass through optical slits, the second position sensors are made in the form of a pair consisting of a radiator and a photodetector, the optical axes of which pass near the edge of the inertial mass , emitters and photodetectors of both position sensors of each plate are fixed on the base and the cover, respectively, with the possibility of fixing the first sensor to move the inertial mass along the longitudinal axis, and the second sensor on the transverse axis, conductive tracks are sprayed on the surface of each inertial mass parallel to the transverse axis, the beginnings and ends which are interconnected by conductive tires, each of which is connected to the output of the first key by means of current leads through the elastic suspension elements of the first inertial mass, to the first input of which a DC source is connected, and the output of the first comparator is connected to the second input, the output of one segment of the photodetector of the first sensor is connected to the first input, and the output of the second segment is connected to the second input, the emitters of position sensors of the first inertial mass are connected to the DC source , conductive tires of the second inertial mass by current leads through the elastic suspension elements of the second inertial mass are connected to the output of the second key to the first input of which I connect ene constant current source and the second input connected to the output of the second comparator, the first input of which is connected to the output of the first segment photodetector of the second sensor and the second input connected to the output of the second segment photodetector second sensor emitters position of the second inertial mass sensors are connected to a DC power source.

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