CN1844933A - Pendulous silicon MEMS angular acceleration transducer - Google Patents

Abstract

The invention discloses a swing silicon MEMS angle accelerator sensor, which is formed by a sensitive element, a capacitor converter, a feedback static torque device, a signal processing circuit and a frame. Wherein, said frame comprises a vacuum package and a base; the sensitive element comprises two anchor points fixed on the base, and a movable polar plate whose two ends are fixed on the anchor points, the flexible support beam of movable polar plate and two symmetry weight blocks on the surface of movable polar plate; the flexible support beam is at the central line of movable polar plate; two symmetry couples of fixed polar plates are embedded at the base under the movable polar plate, while one couple is the sensitive electrodes of capacitor converter, and another couple is the force electrodes of feedback static torque device, which via wires are connected to the capacitor converter and the feedback static torque device; the sensitive angle accelerator of sensitive element will generate the angle displacement around the axle of flexible beam, to detect the angle accelerator. The invention has small volume, lower cost, and the applications for inertia stable controller, angle vibration detecting system and inertia navigation system.

Description

A kind of pendulous silicon MEMS angular acceleration transducer

Technical field

The present invention relates to a kind of pendulous silicon MEMS angular acceleration transducer, can be applied to the stable inertia control system, the angular oscillation test macro, and can be applied to the inertial navigation system of the tactical weapon that the working time is short, cost is low, dynamic range is big.

Background technology

In control, monitoring and the navigation of a lot of moving objects, not only need angular displacement, angular velocity information, more need angular acceleration information.The forties in 20th century, Germany once adopted angular acceleration transducer to be used for the V-2 missile brain, development along with control technology, directly the output movement object is used more and more widely with respect to the YC class angular acceleration transducer of inertial space angular acceleration information, nowadays in the control system of moving objects such as tank, naval vessel, cannon, guided missile, carrier rocket, satellite and space shuttle, all used angular acceleration transducer.YC class angular acceleration transducer also is widely used in the test aspect, startup and the test of braking quality and the stationarity test of accurate mechanical equipment work etc. of for example mobility of aircraft test, the vehicles.Along with science and technology development, the further raising of precision, angular acceleration transducer also can be applied to the inertial navigation system of the tactical weapon that the working time is short, cost is low, dynamic range is big.Developed country such as the U.S., Russia attaches great importance to the research work of angular acceleration transducer, has has successively researched and developed multiple mechanical type and optics angular acceleration transducer.

The development of mechanical type angular acceleration transducer is morning, and kind is more, and wherein mechanical gyro formula angular acceleration transducer is formed by add a small-sized DC tech-generator near single-degree-of-freedom gyroscopy, and this sensor accuracy is higher.The inertial angular acceleration sensor that Bagnes, France enginerring works produce adopts supported has flying wheel than large rotating inertia as sensitive element, has adopted the inductance type transducer.The elasticity ring type angular acceleration transducer that the U.S. and BJ University of Aeronautics ﹠ Astronautics all succeed in developing adopts the equilateral all directions shape ring body of being made up of the rectangle steel plate of eight congruences as sensitive element, adopts foil gauge as transducer.The mechanical type angular acceleration transducer also comprises polytypes such as antivibration ejector half angular acceleration transducer, vortex induction angular acceleration transducer, angular acceleration piezolectric gyroscope, Pendular ring type angular acceleration transducer.Development along with optical technology, adopt Mach-Ceng Teer interferometer or Michelson interferometer principle to develop the optical fiber angular acceleration transducer, on the basis of laser gyro, utilize the speed of moving interference fringes to be proportional to the angular acceleration signal principle that sensor is experienced, designed the laser angular acceleration transducer, optical fiber and laser angular acceleration transducer have improved its stability, reliability and precision owing to do not have movable mechanical structure in the course of work.Existing all mechanical types and optics angular acceleration transducer all are to adopt traditional processing technology manufacturing, and volume and mass ratio are bigger, owing to need manual preparation and assembling, so cost is all higher.

Since late 1980s, along with MEMS (micro electro mechanical system) (Micro-Electro-MechanicalSystem, MEMS) development of technology, various sensors have been realized microminaturization, based on the MEMS angular acceleration transducer of MEMS technology owing to adopt the MEMS processing technology, realized batch process, with the stock of silicon as sensor, so MEMS angular acceleration transducer cost is low, volume is little, low in energy consumption, it is big to have overcome existing angular acceleration transducer quality, the high deficiency of cost has become the main direction of its future development.Japanese Keio university research in 1992 a kind of pressure resistance type silicon MEMS angular acceleration transducer of cantilever beam structure, employing has four cantilever beam structures of pressure resistance type transducer, resolve outside angular acceleration by the variation of detection resistance value, Japanese Yamagata university proposed a kind of loop configuration angular acceleration transducer in 2003, adopted the piezoelectric detection mode to resolve outside angular acceleration.More than two kinds of angular acceleration transducer complex structures, be difficult for processing, and all do not adopt the dynamic balance loop, dynamic range is low, it is big to detect error.

Summary of the invention

Technology of the present invention is dealt with problems and is: overcome the deficiencies in the prior art, propose the pendulous silicon MEMS angular acceleration transducer that a kind of cost is low, volume is little, low in energy consumption.

Technical solution of the present invention is: pendulous silicon MEMS angular acceleration transducer is by sensitive element, the condenser type transducer, feedback static torquer, signal processing circuit and housing are formed, housing comprises Vacuum Package shell and pedestal, sensitive element comprises two anchor points that are connected on the pedestal, a movable pole plate, two two ends are connected in flexible brace summer and two masses that are symmetrically distributed in movable pole plate upper surface on anchor point and the movable pole plate respectively, flexible brace summer is positioned on the center line of movable pole plate, on movable pole plate underlying foundation, the fixed polar plate of embedding two pairs of symmetrical distributions, a pair of is the sensitive electrode of condenser type transducer, a pair of application of force electrode for feedback static torquer, be connected with feedback static torquer with the condenser type translation circuit respectively by lead, the responsive angular acceleration of sensitive element produces around the axial angular displacement of flexible beam, detects angular acceleration with this.

Principle of the present invention as shown in Figure 2, when housing has the angular acceleration input, the responsive housing angular acceleration of sensitive element produces the inertia torsional moment, thereby cause movable pole plate around sensitive axes to producing angular displacement, the condenser type transducer detects this angular displacement by the capacitance detecting mode, and be converted into the electric signal that is directly proportional with angular acceleration, this electric signal is through the filtering of treatment circuit, power amplifiers etc. are handled back output, when electric signal is exported, feedback static torquer detects this output signal, produce a static moment opposite with the inertia torsional moment, make movable pole plate angular displacement be returned to the zero-bit state, realization system closed loop calculates the housing angular acceleration by detecting output signal.

The concrete control principle of the present invention when housing has the angular acceleration input, axially has the responsive housing angular acceleration of mass of big torsional inertia J as shown in Figure 3 around flexible beam Produce twisting inertia moment M _I, have less torsional rigidity k _tFlexible brace summer elasticity of torsion distortion takes place under the effect of this twisting inertia moment, thereby movable pole plate is produced around flexible brace summer axial angle displacement θ:

$\mathrm{\Δ\θ}=\frac{M_I}{{\mathrm{JS}}^2+\mathrm{DS}+k_t}=\frac{J\·\stackrel{\·}{\mathrm{\Ω}}}{{\mathrm{JS}}^2+\mathrm{DS}+k_t}---\left(1\right)$

In the formula, the ratio of damping of D representative system, when movable pole plate generation angular displacement, the capacitance that is embedded in two sensitization capacitance pole plates on the pedestal both sides changes, and electric capacity is respectively:

${\mathrm{<figure-callout\; id="1"\; label="C"\; filenames="A20061001190600101.png"\; state="\{\{state\}\}">C</figure-callout>}}_1=\mathrm{\&epsiv;}\&Integral;\frac{\mathrm{dA}}{z_0+\mathrm{\&Delta;z}}=\mathrm{\&epsiv;}\&Integral;\frac{\mathrm{dA}}{z_0+x\&CenterDot;\mathrm{\&Delta;\&theta;}}---\left(2\right)$

$C_2=\mathrm{\&epsiv;}\&Integral;\frac{\mathrm{dA}}{z_0-\mathrm{\&Delta;z}}=\mathrm{\&epsiv;}\&Integral;\frac{\mathrm{dA}}{z_0-x\&CenterDot;\mathrm{\&Delta;\&theta;}}---\left(3\right)$

In the formula, C ₁And C ₂Represent the electric capacity of two capacitor plates respectively; ε represents specific inductive capacity; DA table table is got pole plate infinitesimal area; z ₀Initial distance between deputy activity pole plate and sensitization capacitance pole plate; Δ z deputy activity pole plate and sensitization capacitance pole plate gap variable quantity can be asked for formula Δ z=x Δ θ; X represents the sensitization capacitance pole plate to distance between flexible brace summer, and two electric capacitys get through the difference of translation circuit:

$\mathrm{\&Delta;C}=C_2-{\mathrm{<figure-callout\; id="1"\; label="C"\; filenames="A20061001190600101.png"\; state="\{\{state\}\}">C</figure-callout>}}_1=\mathrm{\&epsiv;}(\&Integral;\frac{\mathrm{dA}}{z_0-x\&CenterDot;\mathrm{\&Delta;\&theta;}}-\&Integral;\frac{\mathrm{dA}}{z_0-x\&CenterDot;\mathrm{\&Delta;}0})=k_s\&CenterDot;\mathrm{\&Delta;\&theta;}---\left(4\right)$

In the formula, k _sRepresentation transformation device scale-up factor.According to the electrostatic field theory, two parallel capacitance pole plate electrostatic attraction formula are:

$F=\frac{1}{2}\mathrm{\&epsiv;A}{\left(\frac{u}{z}\right)}^2---\left(5\right)$

In the formula, A represents the capacitor plate area; Z represents polar plate spacing, and the voltage u that is applied on the pendulous silicon MEMS angular acceleration transducer application of force capacitor plate is made up of two parts: the one, and bias voltage U ₀, it is a definite value, another is control voltage u _OutWhen angular acceleration was imported, the voltage on two battery lead plates changed, and u is arranged ₁=U ₀+ u _OutAnd u ₁=U ₀-u _Out, two application of force capacitor plate electrostatic attraction moment sizes are respectively M ₁And M ₂, the static resultant moment of generation is M _e:

M _e＝M ₁-M ₂＝∫x _edF ₁-∫x _edF ₂＝k _Fu _out (6)

In the formula, dF _iRepresent application of force capacitor plate attractive force differential; x _eRepresent application of force capacitor plate to the distance between flexible brace summer, k _FRepresent the backfeed loop transfer coefficient, the silicon MEMS angular acceleration transducer input/output relation can be expressed as:

$u_{\mathrm{out}}=\frac{J\&CenterDot;\frac{k_s{k}_V}{{\mathrm{JS}}^2+\mathrm{DS}+{\mathrm{<figure-callout\; id="1"\; label="k\; t"\; filenames="A20061001190600101.png"\; state="\{\{state\}\}">k</figure-callout>}}_t}}{1+\frac{k_s+k_V+k_F}{{\mathrm{JS}}^2+\mathrm{DS}+k_t}}\&CenterDot;\stackrel{\&CenterDot;}{\mathrm{\&Omega;}}---\left(7\right)$

Work as k _VWhen enough big, this angular acceleration silicon MEMS transducer sensitivity can be expressed as:

$S=\frac{u_{\mathrm{out}}}{\stackrel{\&CenterDot;}{\mathrm{\&Omega;}}}=\frac{J\stackrel{\&CenterDot;}{\mathrm{\&Omega;}}\&CenterDot;k_s{k}_V}{k_t+\frac{\mathrm{\&epsiv;}{U}_0{A}_e({2s}_e+b_e)}{z_0^2}{k}_s{k}_V}\&ap;\frac{J}{k_F}---\left(8\right)$

The present invention's advantage compared with prior art is: pendulous silicon MEMS angular acceleration transducer is simple in structure, be easy to processing, torsional inertia is big, remolding sensitivity is higher, the condenser type transducer has improved accuracy of detection, and the dynamic balance backfeed loop has improved the stability and the dynamic range of sensor, this sensor and to have a volume little, cost is low, shock resistance and unfailing performance advantages of higher.

Description of drawings

Fig. 1 is pendulous silicon MEMS angular acceleration transducer one-piece construction figure of the present invention;

Fig. 2 is a pendulous silicon MEMS angular acceleration transducer system principle diagram of the present invention;

Fig. 3 is pendulous silicon MEMS angular acceleration transducer of the present invention system control block diagram.

Embodiment

As shown in Figure 1, the present invention is made up of sensitive element 8, condenser type transducer 9, feedback static torquer 10, signal processing circuit 11 and housing 12, its middle shell 12 comprises Vacuum Package shell and pedestal 1, and sensitive element 8 comprises the flexible brace summer of two anchor points 2, two 4, movable pole plate 3 and two masses 5.As shown in Figure 4, condenser type transducer 9 comprises two sensitive electrodes 6 and translation circuit, and as shown in Figure 5, feedback static torquer 10 comprises two static application of force electrodes 7 and feedback circuit, as shown in Figure 6, input and treatment circuit 11 comprise amplification, filtering, correction, power amplifier.

Movable pole plate 3 in the sensitive element 8 be one along flexible brace summer 4 monosymmetric rectangle silicon plates, in order to reduce system damping, be carved with plurality of square holes at silicon plate glazing.Mass 5 is to be symmetrically distributed in top, movable pole plate 3 both sides, the rectangular parallelepiped derby with big torsional inertia, or siliceous gauge block, and big torsional inertia can improve the resolution of sensor.Anchor point 2 is for being connected in two rigid support points on the pedestal, and flexible brace summer 4 is sliver beams, has very little torsional rigidity and big bendind rigidity, and the sensitivity that can improve sensor reduces mushing error.Flexible brace summer 4 one ends and movable pole plate 3 are connected, and the other end and anchor point 2 are connected, and flexible brace summer 4 is positioned on the center line of movable pole plate 3, thereby have constituted the sensitive element 8 of pendulous silicon MEMS angular acceleration transducer.On movable pole plate 3 underlying foundation 1, the fixed polar plate of embedding two pairs of symmetrical distributions, a pair of is the sensitive electrode 6 of condenser type transducer 9, a pair of application of force electrode 7 for feedback static torquer 10, be connected with feedback static torquer 10 with condenser type translation circuit 9 respectively by lead, constitute the condenser type transducer 9 and the feedback static torquer 10 of pendulous silicon MEMS angular acceleration transducer, the application of force electrode 7 of the sensitive electrode 6 of condenser type transducer 9 and feedback static torquer 10 is the rectangle metal polar plate.The responsive angular acceleration of sensitive element 8 produce around the axial angular displacement of flexible brace summer 4, condenser type transducer 9 is converted to electric signal with angular displacement, the filtering of this electric signal process signal processing circuit 11, power amplifier etc. are handled back output, when electric signal is exported, feedback static torquer 10 detects this output signal, produce a static moment opposite with the inertia torsional moment, make movable pole plate 3 angular displacements be returned to the zero-bit state, realization system closed loop calculates the housing angular acceleration by detecting output signal.

Angular acceleration transducer of the present invention has overcome the deficiency of existing angular acceleration transducer, and it is high to have stability, and the dynamic range large volume is little, cost is low, and the precision advantages of higher can be applicable to the stable inertia control system, angular oscillation test macro, and short inertial navigation system of working time.

It is known that the content that is not described in detail in the instructions of the present invention belongs to this area professional and technical personnel

Prior art.

Claims (5)

1, pendulous silicon MEMS angular acceleration transducer, it is characterized in that: by sensitive element (8), condenser type transducer (9), feedback static torquer (10), signal processing circuit (11) and housing (12) are formed, housing (12) comprises Vacuum Package shell and pedestal (1), sensitive element (8) comprises two anchor points (2) that are connected on the pedestal (1), a movable pole plate (3), two two ends are connected in flexible brace summer (4) and two masses (5) that are symmetrically distributed in movable pole plate (3) upper surface on anchor point (2) and the movable pole plate (3) respectively, flexible brace summer (4) is positioned on the center line of movable pole plate (3), on movable pole plate (3) underlying foundation, the fixed polar plate of embedding two pairs of symmetrical distributions, a pair of is the sensitive electrode (6) of condenser type transducer (9), a pair of application of force electrode (7) for feedback static torquer (10), be connected with feedback static torquer (10) with condenser type translation circuit (9) respectively by lead, the responsive angular acceleration of sensitive element (8) produces around flexible brace summer (4) axial angle displacement, detects angular acceleration with this.

2, pendulous silicon MEMS angular acceleration transducer according to claim 1, it is characterized in that: described movable pole plate (3) be one along the monosymmetric rectangle silicon of flexible brace summer (4) plate, in order to reduce system damping, be carved with plurality of square holes at silicon plate glazing.

3, pendulous silicon MEMS angular acceleration transducer according to claim 1 is characterized in that: described flexible brace summer (4) is two sliver silicon beams, has very little torsional rigidity, but big bendind rigidity is arranged.

4, pendulous silicon MEMS angular acceleration transducer according to claim 1 is characterized in that: described mass (5) is two and is symmetrically distributed in movable pole plate (3) top, the rectangular parallelepiped derby with big torsional inertia, or siliceous gauge block.

5, pendulous silicon MEMS angular acceleration transducer according to claim 1 is characterized in that: the application of force electrode (7) of the sensitive electrode (6) of described condenser type transducer (9) and feedback static torquer (10) is the rectangle metal polar plate.

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