CN1224151A - Navigation grade micromachined rotation sensor system - Google Patents

Abstract

A rolling sensor has a first drive member, a first sensing apparatus having a support element. The first sensing apparatus includes a sensing element connected to the support element. The sensing element is arranged to oscillate rotationally relative to the support element about a sensing axis perpendicular to the drive axis for input rotation rates of the frame about an input axis which is perpendicular to both the sensing axis and the drive axis. A second drive member is connected to the first drive member and is arranged to produce rotational oscillations about the drive axis that are opposite in direction to the rotational oscillations produced by the first drive member. The second sensing apparatus has a second sensing element arranged to oscillate rotationally relative to the support element about second sensing axis that is parallel to the first sensing axis.

Description

The rotation sensor-based system of navigation level micromachined

The present invention relates generally to the rotation sensor of the occasion that is used to navigate and so on.The present invention especially relates to when working in a kind of high G at the aircraft of reentrying etc., the high vibration environment can provide high-precision rotation sensor-based system.More particularly, the present invention relates to a kind of rotation sensor-based system based on silicon, it has the Coriolis acceleration sensor of measuring around the rotating speed of two quadrature sensing axis.

The Ke Shi of the micromachined in the past rotates sensor-based system and has shown and depart from repeatability (biasrepeatability) in 10 ° to 1000 °/hour scope.According to the analysis of these principles, although the low cost that its rotation sensor-based system according to the invention is provided with at present and the purpose of high reliability do not show its performance reliably and can improve three to five orders of magnitude and produce precise navigation level equipment.

Rotation sensor of the present invention has an installing plate that is arranged in the housing, is provided with a plurality of flexible damping pads between housing and the installing plate.From the installing plate wheel hub that extends out, in order to produce the whirling vibration around a driving axis, this wheel hub is connected with one first actuator.

Actuator is connected with first sensing device with a supporting member, thereby actuator can be delivered to supporting member around the whirling vibration of driving axis.First sensing device also has a sensing element, and it is connected in supporting member, and is arranged to vibrate around driving axis with supporting member.Sensing element is arranged to wind perpendicular to the input speed of an input axis of sensing axis and driving axis in response to framework and is wound a sensing axis whirling vibration perpendicular to driving axis with respect to supporting member.Sensing element make its moment of inertia around driving axis be substantially equal to around its perpendicular to the moment of inertia of two main axiss of driving axis and.This rotation sensor also has and is used to produce as the device of sensing element around signal function, the expression input speed of the amplitude of the first sensing axis.

This rotation sensor comprises that also one is connected in second actuator of first actuator.This second actuator is arranged to produce the whirling vibration that is in reverse to the whirling vibration that first actuator produced around driving axis.This actuator is connected with one second sensing device, and it is preferably identical with first sensing device basically.Second sensing device has one second sensing element, it is arranged to can be with respect to supporting member and around the second sensing axis whirling vibration that is parallel to the first sensing axis, and have and be used to produce as the device of second sensing element around signal function, the expression input speed of the amplitude of the second sensing axis.

The second sensing axis is preferably perpendicular to the first sensing axis.

Rotation sensor of the present invention can be made to have a wheel hub that extends out from a pedestal and first cover and is formed at drive electrode on the pedestal.One driving element is installed on the wheel hub.Be formed with the second cover drive electrode on this driving element, it is corresponding with the first cover drive electrode.Pedestal and driving element are arranged to face with each other, the appropriate section of the first and second cover electrodes is staggered on angle each other, thereby electric signal puts on first and second covers and can produce torque on the electrodes on driving element, and this torque produces around a driving axis whirling vibration driving element in a plane.This rotation sensor also has a sensing part, and it is made has an external support ring that is installed on the driving element, thereby the whirling vibration of driving element can be delivered to sensing part.Sensing part also has a sensing element and an a pair of torque rod that is connected between external support ring and the sensing element in sustained ring, and this is to the torque rod alignment and limit an output sensing axis.

Fig. 1 is the exploded perspective view of Solid Double axis rotation sensor of the present invention;

Fig. 2 is the stereographic map that can be included in the speed sensing element in the rotation sensor of Fig. 1;

Fig. 3 is the stereographic map that can be included in the part of the actuator in the device of Fig. 1;

Fig. 4 is the cut-open view that can be included in the flexibility bar in the device of Fig. 3;

Fig. 5 is the upward view that can be included in actuator and the sensor sensing element in the device of Fig. 1 and reverse electrode;

Fig. 6 is the vertical view of the actuator of Fig. 1 and Fig. 5;

Fig. 7 can be included in the cut-open view that the rotation sensory package in the device of Fig. 1 is cut open along the 7-7 line among Fig. 5, and this assembly has a capacitance signal sensitive element;

Biasing and electric signal that Fig. 8 schematically illustrates Fig. 7 device pick up;

Fig. 9 shows the circuit of the signal of handling the output of Ke Shi rotation sensor, and sensor all has the independent sensing element of collecting to every axis;

Figure 10 is the block scheme of the supplementary features of key diagram 9 circuit;

Figure 11 is an overall block-diagram of handling the circuit of Ke Shi rotation sensor output signal, and wherein two sensing elements are combined in the collecting loop of every axis simultaneously;

Figure 12 is the exploded perspective view of solid-state mono-axial rotation sensor of the present invention;

Figure 13 is the vertical view that is included in the sensing element in this embodiment of the invention shown in Figure 12;

Figure 14 is the vertical view that is included in the driving element in this embodiment of the invention shown in Figure 12;

Figure 15 is the upward view of the driving element of Figure 14;

Figure 16 is the cut-open view of cutting open along the 16-16 line among Figure 14;

Figure 17-19 can be included in the cut-open view of the torque member in the sensing element of Figure 12 and 13;

Figure 20 A is the exploded perspective view of second embodiment of the anti-angle of throw rate sensor of biaxial two-phase of the present invention;

Figure 20 B is the exploded perspective view of dual sensor of the present invention, mono-axial rotation sensor;

Figure 21 is the cut-open view of the device of Figure 20 A;

Figure 22 is the exploded perspective view of the 3rd embodiment of solid-state mono-axial rotation sensor of the present invention;

Figure 23 is the device of two Figure 22 of combination of the present invention and produce the cut-open view of the device of the anti-angle of throw rate sensor of a biaxial two-phase;

Figure 24 is the stereographic map of a sidepiece of the driving element of Figure 22, shows an anodal bonding land and many drive electrodes.

Referring to Fig. 1, rotation sensor 20 of the present invention comprises a pedestal 22, and this pedestal has a bottom 23 and a top cover (not shown), and top cover is preferably basic identical with bottom 23.Pedestal 22 has a roughly rectangular cross section.Pedestal 22 comprises the abase frame 24-27 that is installed in 28-31 place, corner in the pedestal 22 respectively.

Rotation sensor 20 comprises a pair of speed sensing part 34 and 36, and they are preferably identical.Each speed sensing part 34 and 36 is preferably made by micromachined by the single piece of silicon crystal.Rotation sensor 20 also comprises a pair of actuator 38 and 40, and they also are identical, and each is all made by the single piece of silicon crystal.

Fig. 1 shows speed sensing part 34 and 36 facing surfaces 42 and 44.As shown in Figure 1, when assembling during rotation sensor 20, the surface 42 of speed sensing part 34 is joined on the lower surface of actuator 38.Equally, with the lower surface engages of speed sensing part 36 to actuator 40.

Actuator 38 has a frame 50, and it roughly is expressed as rectangle in the drawings so that explanation.Frame 50 also can have other profile.Referring to Fig. 3, the middle body 52 of actuator 38 upper surfaces 54 is thinner than frame 50.Referring to Fig. 1 and 3, middle body 52 has side 55-58, and they are connected on the frame 50 by flexibility bar 60-63.Flexibility bar 60-63 preferably extends to frame 50 from the center of side 55-58.In Fig. 3, omitted part actuator 38, so that clearly show that middle body 52 and flexibility bar 60-63.Fig. 4 shows the section of flexibility bar 60, and it is formed by the silicon crystal etching.Shown in Fig. 1,3,4 and 7, flexibility bar 60-63 is preferably identical, and has the ability of higher opposing at vertical in-plane bending.Flexibility bar 60-63 opposing is lower in the ability of horizontal in-plane bending, thereby middle body 52 can be to vibrate around the small size rotation of the vertical axis by its geometric center.

Fig. 5 shows the bottom side of actuator 38.This actuator 38 has four and reverses electrode 227a-227d, and they can be made by the selected part of metalized actuator 38.These reverse electrode 227a-227d preferably and shown in Figure 1 be positioned on the actuator 40 to reverse electrode 228a identical with 228d.Sensing element 110 and 112 is respectively in the face of reversing electrode 227a-227d and 228a-228d.Reverse electrode and can be used to apply feedback torque to sensing element 110 and 112, this will be below to illustrating in the description that can be included in the signal processing apparatus in the present invention.

Referring to Fig. 1 and 6, carry out suitably metalized by all parts to the crystal of making actuator 38, on actuator 38, form four groups of electrode assemblie 70-73.This electrode assemblie is connected in middle body 52 between flexibility bar 60-63.Referring to Fig. 6, for example, the oblique dashed area of electrode assemblie 70 is represented the electrode 80-88 that separates.Electrode 80-88 is with respect to the corner 90 of electrode assemblie 70 and be positioned in the identical actuator 40, and angular displacement takes place corresponding electrode mutually.

When actuator 40 is reversed and makes electrode assemblie face-to-face, can produce displacement between the corresponding electrode.The mode of vibration that this angular displacement of the electrode in two actuators 38 and 40 can make electrode be added the frequency of frequency to be twice in attracts each other, causes the rightabout whirling vibration of electrode with the corresponding middle body of actuator.These two actuators are connected with electric signal source, in order to apply drive signal on electrode.Drive signal preferably drives each actuator with its resonant frequency.Actuator 38 is preferably identical with 40 resonant frequency, generally is about 5kHz.

Two central driver 38 and 40 form an opposite torsional resonance mechanical vibrator together.The speed sensing part 34 and 36 in two outsides forms the tuning inertia speed sensor-based system of a biaxial together.

Referring to Fig. 1,3 and 7, the thickness of the middle body 52 of actuator 38 is less than the thickness of frame 50.The middle body 150 of actuator 40 is also thin than its frame 100.When the frame 100 of the frame 50 of actuator 38 and actuator 40 was bonded together, the thickness difference of middle body and frame formed a little gap between middle body.

Referring to Fig. 1,2 and 7, speed sensing part 34 and 36 has sensing element 110 and 112 respectively.Speed sensing part 34 has a middle body 120 and a plurality of flexible sheets spring 122-125 that extends to sensing element 110 from middle body 120.Equally, speed sensing part 36 has the sheet spring 130-133 that extends to sensing element 112 from its middle body 121.Sensing element 112 is preferably formed as a structure that roughly is thin rectangular shape, and it has a roughly rectangular central opening 113.As can be seen, middle body 121 is thicker than sensing element 112 from Fig. 2 and 7, and sensing element 112 is thicker than sheet spring 130-133.Coriolis acceleration ac can cause these vibrations, and it forces sensing element 110 and 112 around the vibration of the output of the x-shown in Fig. 2 axis.The input rate that shown Coriolis acceleration equals twice is taken advantage of the spot speed v of the sensing element 112 that the dither actuation movement produced ⁺

Fig. 7 represents actuator 38 and 40 is bonded together, then speed sensing part 34 and 36 is engaged in the middle body at the actuator 38 and 40 back sides respectively and the structure that produces.Only speed sensing part 34 and 36 the thickest middle bodies 120 and 121 are engaged in corresponding driving part 38 and 40 respectively.Therefore, sheet spring 121-125 and 130-133 can with by a small margin in the paper plane of Fig. 7 along the z axis free vibration shown in Fig. 1 and 2.

Referring to Fig. 1 and 7, with actuator 38 and 40 and after speed sensing part 34 and 36 is bonded together, place them in the pedestal 22, actuator 38 is contacted with abase frame 24-27 with 40 corner.Each abase frame 24-27 is preferably formed as to comprise a damping flexible member between the frame 50 of mechanical vibrator supporting base 22 and actuator 38.This flexible member is essential for guaranteeing that opposite rotary machine Vib. has single resonant frequency.This flexible member also has the adjection of decay external vibration input.

When rotation sensor 20 is assembled into fully, and when driving voltage being applied on the electrode assemblie of two actuators 38 and 40, rotation sensor 20 just can be used for detecting the rotation of the isoplanar axis that is designated as X and Y in Fig. 1 and 2.In speed sensing element 110 and 112, produce the vibration of Different Plane around the rotation input of X or Y-axis line.The vibration of these Different Plane is that the coriolis force of the Different Plane that produced on an object that rotates because of the axis in plane as shown in Figure 2 in this plane internal vibration causes.Sheet spring 122-125 and 130-133 allow the vibration around an amount of Different Plane of isoplanar axis of rotating in response to input.The resonant frequency of two speed sensing parts 34 and 36 on the X-axis line is preferably equal substantially.Equally, speed sensing element 110 is preferably also identical with 112 Y-axis line resonant frequency.These resonant frequencies preferably equal the vibration frequency of actuator.

Around the vibration of the caused Different Plane of input speed of X-axis line or Y-axis line cause actuator 38 and 40 and corresponding speed sensing element 110 and 112 between the variation of relative displacement.The displacement of these variations can be used as changes in capacitance, and it provides capacitive to pick up, and will explain below.

In Fig. 1 and 7, the middle body of actuator 40 is by label 150 expressions.Actuator 40 also is illustrated as having respectively flexibility bar 61 and 63 corresponding flexibility bars 152 and 154 with actuator 38.

Fig. 8 schematically shows picking up of capacitive signal.Oscillator 160 provides ω to speed sensing element 110 and 112 _cThe benchmark pumping signal of frequency.The voltage of benchmark pumping signal is about 10V, frequencies omega _c= 250kHz.Capacitor 162 and 164 is formed between actuator 38 and the speed sensing element 110. Capacitor 166 and 168 is formed between actuator 40 and the speed sensing element 112.With one be about+driving voltage of 10V is added on capacitor 162 and 166.With one be about-driving voltage of 10V is added on capacitor 164 and 168.Electric wire 170-173 sends the oscillator signal of expression rotating speed to signal processing circuit discussed below.

Referring to Fig. 9, there is shown a kind of citation form of the signal Processing that is used for the embodiment of the invention, wherein embodiments of the invention all have two such as at the sensing element shown in speed sensing part 34 and 36 to every axis in X and the Y-axis line.Rotating speed can put on the first and second X-axis line sensing elements 200 and the 202 and first and second Y-axis line sensing elements 204 and 206.The first and second X-axis line sensing elements 200 and 202 output are input to a totalizer 208 respectively.Equally, the first and second Y-axis line sensing elements 204 and 206 output are input to a totalizer 210 respectively.Then, totalizer 208 and 210 offers quantizer with X and Y-axis line turn signal.

Sensing circuit 200-206 can be identical.Figure 10 shows a kind of structure that is used for each circuit of four sensing circuit 200-206.Angular speed puts on the rate sensor 34.One picking up assembly 214 can produce an electric signal, the response of 110 pairs of rotating speeds of this signal indication sensing element.The signal indication of picking up assembly 214 outputs is with frequencies omega _DThe coriolis force that causes of opposite rotation actuation movement produce the dynamic modulation signal, as shown in Figure 2.These in-phase signals can be expressed as the cosine function of drive signal arbitrarily.Represent that the signal of 90 ° of phase differential dynamic errors then can be characterized by the sine function of drive signal.

Then, the output of picking up signal assembly 214 is amplified by an amplifier 230.This amplifier 230 offers a pair of detuner 232 and 236 with output, and they use sin ω respectively _DT and cos ω _DT comes restituted signal.Detuner 232 and 236 output are imported into corresponding servo compensation circuit 234 and 237 respectively.The signal output of servo compensation circuit 234 is to deliver to the suitable totalizer 208 of Fig. 9 or 210 angle rate signal. Servo compensation circuit 234 and 237 output signal also are imported into respectively reverses modulation circuit 238 and 240, and they use sin ω respectively _DT and cos ω _DT modulates the signal that is input to them.The output signal of reversing modulation circuit 238 and 240 is transfused to a totalizer 242.The output of totalizer 242 and then the sensing part that is admitted on the actuator 38 of Fig. 5 reverse electrode 227a-227d, to provide feedback torque to sensing part 34.

Figure 11 shows the signal processing circuit of the signal combination of two sensing elements wherein at a collecting loop.The input of one X speed is applied to and just is driving frequency ω _DDescend on the sensing part of modulating with coriolis force 34 and 36.Pick-up circuit 254 and 256 is in frequencies omega _DProduce the amplitude response of the first and second speed sensing parts 34 and 36 down.Amplifier 260 and 262 is amplifying circuit 254 and 256 signals of exporting respectively.Totalizer 264 produce indication circuits 254 and 256 output signals and signal, totalizer 266 produces the signal of indication circuits 254 and 256 output signal differences.Then, these are transfused to a detuner 270 with signal and difference signal, and it carries out homophase and 90 ° of phase differential demodulation.The output of detuner 270 is transfused to a servo compensation circuit 272, it so that produce measured rotating speed around the X-axis line.

The signal that the servo oscillation device 274 of actuator is exported is connected to detuner 270, and is connected to modulation and adding circuit 276, and it carries out homophase and the torque modulation of 90 ° of phase differential and add operation mutually.Modulation and adding circuit 276 receive the signal of servo compensation circuit 272, and the sensing element in sensing part 34 and 36 110 and 112 provides a feedback torque signal.

The present invention preferably has the device same as shown in Figure 11 that is used for the Y-axis line.

Figure 11 represents that the signals of two sensing parts 34 and 36 outputs carried out addition and subtract each other before applying feedback torque.This method has improved the tuning Q value of output axis.If each sensing part all is collected separately, then the Q value will be carried out phase locking with the reversal of vibrations pattern to feedback torque owing to can not balance each other in the anti-torque of each sensing part the time and be reduced.If each sensing part is collected separately, then energy will be at the abase frame inner dissipation.For the thoroughly deflection of collecting sensor, homophase and 90 ° of phase signals and and signal must all be zero with difference signal.The signal of the speed that expression is applied is the in-phase component of difference signal.Other feedback torque is done the correction of common mode and 90 ° of phase differential torque aspects according to undesirable crosslinked input and angular acceleration input.

Rotation sensor 20 of the present invention is had several remarkable and unique features, and they can reduce vibration rectification errors and improve the biasing repeatability.These features can make rotation sensor 20 meet the performance and the environmental requirement of rotation sensor 20, to meet following navigation request:

Repeatable-0.01 °/hour of biasing;

Scaling ratio error-1,000,000/20;

Angle random moves-0.001 °/√ hour;

G sensitivity is less than 0.01 °/hour/G.

At first, overlap with its center of suspension, two axis are all realized the common mode inhibition of linear oscillator by the center of gravity that makes sensing element 110 and 112.And, the same with the vibration rate sensor that is used for other mechanical type, the phase place of independent acceleration transducer and the coupling of gain and follow the tracks of unimportant.The second, inertia speed sensing element is mechanically isolated with the driving force of the Different Plane that causes biased error.The 3rd, actuation movement does not cause the relative motion between inertia speed sensing element and its sensitive element, and this is because each actuator and relevant sensing element thereof are done as a whole mobile together.The 4th, actuator 38 and 40 and the torque of sensing part 34 and 36 machinery vibration component be reverse balance, this can reduce to minimum to the susceptibility of the exterior mechanical impedance variation that can cause biased error equally.

Actuator 38 and 40 mechanical vibration can be biaxial Ke Shi angular speed sensing necessary vibration velocity excitation are provided.The elasticity coefficient of four flexible member 60-63 has been set up the Vib. resonant frequency jointly with the inertia of the vibrating elements 52 that links to each other with other four flexible members of actuator 40 and 34 and the inertia of vibrating elements 36 and 150, the peak velocity amplitude comes sensing by the Vib. sensitive element simultaneously, and is controlled by signal being added to the lip-deep relatively drive electrode of oscillating plate two by drive electronics.Oscillating plate two lip-deep relatively be sensitive element/afterburning electrode, every axis that they are used to force inertia speed sensing element is balance again.Should notice that all drivings, sensitive element/afterburning electrode and electric contact all are limited in the mechanical vibrator.

The free-running frequency of mechanical vibrator is about 5KHz, and total resonant frequency of rotation sensor chip and abase frame flexible member is about 1KHz.Therefore, can satisfy the bandwidth of needed 500Hz at an easy rate.

During work, last speed sensing part 36 is driven into by actuator 38 and 40 with following speed sensing part 34 and differs 180 ° of phase places.Upper and lower speed sensing element 110 and 112 responds the angular speed input of winding perpendicular to an axis of mechanical vibrator axis by the axis vibration of winding perpendicular to input axis and mechanical vibrator.This Ke Shi induction vibration component of speed sensing element is by X and Y-axis line capacitive sensitive element sensing, as shown in Figure 8.The signal of these sensitive elements is added on the X and Y passage of rotation sensor servo electronics, and this electronic equipment provides feedback voltage, thereby speed sensing element 110 and 112 is applied electrostatic force and makes its vanishing.The X and the Y component of the size of the feedback voltage on every axis and the angular speed of input are linearly proportional.

Signal processing circuit compensates homophase and 90 ° of phase signals in such a way, that is, make loop in the mechanical vibrator frequencies omega _DOn have the gain of integer, the dc signal that is directly proportional with angular speed is provided simultaneously.

Referring to the quantizer among Fig. 9 212, use band to cross the double range conversion plan of the feature of taking a sample at a high speed.The tetravalence Δ ∑ modulator of high dynamic range will be simulated rate signal and be converted serial bit stream to, and each represents an angle Δ θ.Then, microprocessor is taken a sample these Δs θ position phase adduction under the 5KHz that is higher than 10 times of bandwidth, and makes fast averaging.Because signal contains interference, this processing causes the resolution that improves.

Sensor 20 is preferably with closed loop mode work, and this can make sensing axis modulated humorous, moves the decline that the order of magnitude is arranged than open loop device at random thereby make.For example, moving with its bandwidth at random of open loop tuning fork gyroscope instrument reduces pro rata, continues to reduce because the sensitivity meeting of sensitive element reaches higher bandwidth with its vibration frequency of further being left under order tuning fork.

The stress of vibratory drive motion or its generation can not appear on the sensitive element.Move with sensing element by the pedestal that makes the displacement sensitive element, can eliminate a kind of error source that harm is arranged most fully.These characteristics have been eliminated the bonding at the imperfect place on the vibration plane of their sensing elements when vibrating fully on sensitive element.Even the surface smoothness of the silicon of micromachined is about 0.02 microinch, it be still for 0.01 degree/hour the big many orders of magnitude of motion amplitude differentiated of the required quilt of performance.This motion sensitive Element Technology has also been eliminated the influence that causes because of any minimum inclination of sensing element during micromachined.The signal combination that this inclination caused is to amassing in the output that is directly proportional with this inclination and angular amplitude are.In many other Ke Shi sensing devices, sensitive element uses piezoresistance or piezoelectric stress sensing transducer to detect coriolis force.Unfortunately, these sensitive elements must be separated all stress that drive vibration, and this stress is bigger tens times than the stress of differentiating 0.01 degree/hour required.

The invention provides the common mode inhibition of intrinsic linear oscillator.Sensing element 110 and 112 is inherent balances, thereby its center of gravity is just on its center of suspension.The same with many other designs, they are not cantilevered.Therefore, not having output concerning the linear oscillator input produces.For cantilevered detection quality, make the signal difference of two outputs, to suppress sensitivity to vibration.This means that for this removal, good gain and phase matching are critical.

For the resonant frequency of 5000Hz and the peak velocity of 0.5 meter per second, to 0.01 °/hour input rate, the peak value Coriolis acceleration is 0.005 μ G.The peak value output shaft displacement of the lines of this acceleration when 5000Hz is 5.1 * 10 ^-11Micron.For the conservative Q value 500 around the output axis, this motion will be amplified to 2.5 * 10 ^-8Micron.Sensitive element with minimum gap of 10 microns will produce 1.2nV for 5V electric bridge source, estimate that parasitic and back side electric capacity will reach 5 times of gap capacitance.This will cause scaling ratio be the every degree of 120nV/hour.Be better than the instrument amplifier of 4nV/ √ Hz with the interference of today, the white spirit of rotation sensor disturb be better than 0.05 degree/hour/√ Hz, can convert RMS to and carry out the all-wave demodulation.This interference is convertible into than 0.001 degree/√ hour and better moves at random.If obtain higher Q value, then this numeral will reduce in proportion.

When rotation sensor 20 work, the coriolis force that speed produces when being applied to the axis that winds perpendicular to the vibration axis will force all sensing elements to do the vibration of the Different Plane that tilts.The signal that is installed in all sensitive element output on all plates adjacent to all sensing elements is measured these motions, and is used to produce feedback torque after amplifying, to eliminate the influence of coriolis force.Keeping sensing element 110 and 112 is that the required torque of zero-bit is the measured value of input angle speed.

Figure 12-16 shows the embodiment of a simplification physical construction of the present invention.Rotation sensor 300 is the mono-axial formula of the first half of the rotation sensor 20 of Fig. 1 substantially as can be seen.This rotation sensor 300 can be with open loop or closed loop work, and make by micromachined or by electrodischarge machining.

This rotation sensor 300 has a pedestal 302, a driving element 304 and a sensing part 306.Pedestal 302 has a columniform outer wall 308, and it is around the cylindrical region 310 of a hollow.Pedestal 302 has the upper end and a lower end of opening, and the lower end comprises a base plate 312.Base plate 312 projections have a central hub 314.Be formed with the interconnected drive electrode 316 of a cover by metallization process on the base plate 312.

Driving element 304 has one external torque/sensing ring 320, and it is embedded in the cylindrical region 310 of pedestal 302.Figure 15 is the upward view of driving element 304, shows to be formed at the interconnected drive electrode 322 of the cover of second above it.What their appropriate section of being arranged to this two covers electrode 316 and 322 went up form an angle with each other departs from.Electric signal alternately puts on the electrode and can produce torque between actuator 304 and pedestal 302.

Figure 12 and 14 shows the upper surface of driving element 304.This surface of driving element 304 is divided into two essentially identical metallic electrodes 330 and 331, and they can be used for picking up of signal and apply feedback torque to sensing part 306.

Driving element 304 has central authorities wheel hub 340 is installed, and it is installed on the central hub 314 of pedestal 302 projections.This central authorities' fabricated section 340 is made by suitable etching or micromachined technology by the material that forms driving element 340.Central authorities' fabricated section 340 substantially can cylindrical or rectangle, and is connected in outer shroud 320 by many thin bar 350-353, as shown in figure 14.Bar 350-353 is preferably on the angle apart 90 °.

Interact and the driving torque that produces causes bar 350-353 deflection by two cover drive electrodes 316 and 322, thereby driving element 304 is vibrated around driving axis in a plane.Sensing part 306 has an external support ring 360 and a sensing element 362.Sustained ring 360 is installed on the outer shroud 320 of driving element 304, thereby sensing part 306 also can vibrate around driving axis.

Sensing element 362 is installed on sustained ring 360 by a pair of torque rod 364 and 366 that radially extends.Figure 17-19 shows the various cross section of torque rod 364 and 366.Article one, determined the output axis of rotation sensor 300 by the line of torque rod 364 and 366.

When rotation sensor 300 when driving axis vibrates, coriolis force causes sensing element 362 response to rotate around its output axis around the rotation of input axis.Capacitance variations between the metalized portion 330 and 331 of sensing element 362 and driving element 304 is represented the slewing rate of rotation sensor 300.

Metalized portion 330 and 331 and the bottom surface of sensing element 362 also can be used to apply feedback torque to sensing element 362.In normal work, apply enough torques so that sensing element 362 is corrected to its neutral position.The output of sensor is must be applied to the torque electrode to be in the electric signal of neutral position to keep sensing element 362.

If sensing element 362 is designed to have a frequency of natural vibration that is different from driving frequency.Then sensor 300 can be with operate in open loop state.In this case, pickoff signals can be amplified, carry out demodulation with the driving frequency reference signal then, thereby produce the angular speed sense data.

Figure 20 A shows the two reversal of vibrations angular rate sensors 400 of biaxial of the present invention.Sensor 400 has upper and lower driving element 414,416, and they are preferably roughly the same with above-mentioned driving element 304.Sensor 400 also has upper and lower sensing part 412,418, and they are preferably also roughly the same with above-mentioned sensing part 306.

Sensor 400 has an installing plate 402 that is arranged in the housing 404.Be provided with the damping pad 406 of a plurality of flexibilities between the base plate 408 of installing plate 402 bottoms and housing 404.Installing plate 402 has the central hub 410 of a projection.When sensor 400 all assembles, a lid 420 is fixed in the upper limb of housing 404, thereby stops entering and guarantee and under vacuum, working of outside impurity.

The central hub 410 of installing plate 402 projections extends through down the centre gangway 440 in the sensing part 412.Following driving element 414 has a central mounting portion 438, and the bottom surface of this central authorities mounting portion is installed on the upper surface of central hub 410 of projection.Following sensing part 412 has an outer rim 442, and this outer rim is connected in down the outer rim 444 of driving element 414.Last actuator 416 has a central mounting portion 446, and this central authorities mounting portion is connected in down the central mounting portion 438 of actuator 414.Last sensing part 418 has an outer rim 450, and this outer rim is installed on the outer rim 452 of driving element 416.

Last driving element 416 is identical with following sensing part 412 with following driving element 414 respectively with last sensing part 418.In the time of in being installed on sensor 400, last driving element 416 and last sensing part 418 are respectively with respect to driving element 414 and following sensing part 412 are inverted down.

Following sensing part 412 is arranged to have one first torque axis, and this axis is limited by the torque rod 454 and 456 of a pair of radially aligned of supporting one sensing element 460.Last sensing part 418 is arranged to have one second torque axis, and this axis is limited by the torque rod 462 and 464 of a pair of radially aligned of supporting one sensing element 466.For the biaxial rate sensor, the second torque axis is preferably perpendicular to the first torque axis.

Driving element 414 and 416 has drive electrode 470 and reverses electrode 472.The drive electrode of following driving element 414 and last driving element 416 staggers driving element 414 and last driving element 416 corresponding electrode basically toward each other each other on angle, such as previously discussed.Therefore, driving voltage puts on and can cause driving element 414 and 416 the bar 478-481 in following driving element 414 and the bar 484-487 in the last driving element 416 and vibrate in the isoplanar on the drive electrode.Therefore, driving element 414 and 416 and the assembly of sensing part 412 and 418 vibrate around the driving axis shown in Figure 20 A.The direction of vibration of last driving element 416 and last sensing part 418 is opposite with following driving element 414 and following sensing part 412.These vibrations are the twices that put on the driving signal frequency of drive electrode 470, thereby any drive signal that is connected in sensing part 412 and 418 can not be detected as rate error.

Figure 20 B shows a kind of mono-axial speed probe 400a.The difference of sensor 400a and biaxial sensor 400 only is that the following sensing element 412 of Figure 20 A is replaced by a sensing element 418a, and the sensing element 418 of this sensing element and Figure 20 A is roughly the same.The numbering of all members of this sensing element 418a is identical with sensing element 418, has just added letter " a ".

Sensing element 418a has torque rod 462a and 464a, and they are parallel to torque rod 462 and 464 respectively.Therefore, these two sensing elements 418 have the sensing axis that the parallel torque axis by sensing element 418 and 418a is limited with 418a.Speed probe 400a has the advantage that common mode inhibition can be provided the angular oscillation of importing this mono-axial sensing device.

Figure 21 be Figure 20 A sensor 400 by at bonding land 411a-411d with the cut-open view of all member engages after being fully assembled together.

Figure 22 shows another embodiment of the present invention.Figure 22 represents an angular rate sensor 500, and it has the sensing part 506 and the one sensitivity/torsion element 508 of a driving element 502, a driven element 504, a conduction.

Driving element 502 preferably includes a substrate 509 of being made by Pyrex glass, pottery or other similar insulating material.Driving element 502 goes out a plurality of drive electrodes 510 and a plurality of driving sensitive electrode 512 through metalized on the surface of substrate 509.Driving element 502 preferably has a center rectangle bonding land 513.

Figure 24 shows the surface 514 of driven element 504 in the face of driving element 502.It is a silicon chip that driven element 504 is preferably formed as.Be formed with a plurality of electrodes 516 on the surface 514 of driven element.These electrodes 516 etch groove 517 backs and remain in surface 514.Preferably channel erosion is carved into about 0.003 " the degree of depth.Then, metallized and formation electrode 516 in the bottom surface of groove.Electrode 516 deviates from drive electrode 510 on angle, thereby applies electric signal can produce a torque on driven element 504, its mode identical with described in above other embodiments of the invention.

The middle body of driven element is anodic bonding district 518, and it is bearing on two couples of bar 520-523 that radially extend.This anodic bonding district 518 is roughly rectangular.Bar 520-523 vertically stretches out from the sidepiece in anodic bonding district 518.The surface 514 of driven element is preferably from the about 5 microns distance of the downward etching in anodic bonding district.Anodic bonding district 518 and bar 520-523 preferably make by active-ion-etch (RIE) technology.

Referring to Figure 22, the upper surface 530 that is driven anode 504 preferably applies oxide skin(coating) 531, so that electrical isolation to be provided again.The lower surface of sensing part 506 preferably also applies oxide skin(coating) 533.

Sensing part 506 has a roughly rectangular housing 540.Only carry out etching, thereby in housing 540, form a sensing element 542 in the inboard of housing 540 outsides.Etch process has stayed roughly rectangular sensing element 542, and it is by between two two opposite ends that extend sensing element and housing 540 and the torque rod 544 of radially aligned and 546 supportings.Housing 540 is fixed in the upper surface 530 of driven element 504, thereby the vibration of driven element 504 can be delivered to sensing part 506.

Sensitivity/torsion element 508 is preferably made by Pyrex glass, pottery or other similar insulating material.Sensitivity/torsion element 508 is engaged in the housing 540 of sensing part 506.Sensitivity/torsion element 508 has pair of metal part 550 and 552, and they can be used as electrode, so that ground connection to be provided, as shown in the figure, or provides bias voltage to driven element 504.Come the lead 554 and 556 of self- electrode 550 and 552 to pass centre gangway 560 in sensitivity/torsion element 508 and the opening 548 in the sensing element 542.

The picking action of sensing element 542 detects and reverses by electrode 557 and 559 and provides, and this two electrode is metallized in the bottom of sensitivity/torsion element 508.

Figure 23 is how two image sensor 500 such sensors of expression can back-to-back be installed, thereby is provided at the cut-open view that does not have the sensor-based system of reacting force on its shell 602.With sensory package 604 on one and once sensory package 606 be installed on the opposite side of a Connection Element 608.The sensing axis of last sensory package 604 and following sensory package 606 is each other in 90 °, thereby a biaxial sensor is provided.Another kind method is that the sensing axis can be arranged in parallel, thereby the double precision mono-axial sensing operation that has angular oscillation to suppress to the frequency near driving frequency is provided.

Connection Element 608 has a pair of flange 610 and 612 that extends towards shell 602.Pair of brackets 614 and 616 are installed in the shell 602, are used for admitting flange 610 and 612 respectively.Around be on the shear direction that is driven axis flexible reversed support 620 be preferably disposed on flange 610 and 612 with their corresponding supports between so that sensor-based system 600 can by the unifrequency reversal of vibrations encourage be driven.

Claims (6)

1. rotation sensor comprises:

One housing;

One is arranged on the installing plate in the housing, is provided with a plurality of flexible damping pads between housing and the installing plate;

One wheel hub that extends out from installing plate;

One is connected in first actuator of wheel hub, and this first actuator is arranged to produce the whirling vibration around driving axis;

One first sensing device, it has a supporting member that is connected in actuator, thereby actuator can be delivered to supporting member around the whirling vibration of driving axis, and this first sensing device also has:

One be connected in supporting member and be arranged to can be with supporting member around driving axis vibrating sensing element, this sensing element is arranged to wind perpendicular to the input speed of the input axis of sensing axis and driving axis with respect to supporting member in response to framework and is wound sensing axis whirling vibration perpendicular to driving axis, this sensing element make its moment of inertia around driving axis be substantially equal to around its perpendicular to the moment of inertia of two main axiss of driving axis and; And

Be used to produce as the device of sensing element around signal function, the expression input speed of the amplitude of the first sensing axis;

One is connected in second actuator of first actuator, and this second actuator is arranged to produce the whirling vibration that is in reverse to the whirling vibration that first actuator produced around driving axis;

One is connected in second sensing device of this actuator, this second sensing device is identical with first sensing device basically, and has one second sensing element, this element is arranged to can be with respect to supporting member and around the second sensing axis whirling vibration that is parallel to the first sensing axis, and have and be used to produce as the device of second sensing element around signal function, the expression input speed of the amplitude of the second sensing axis.

2. rotation sensor as claimed in claim 1 is characterized in that, the second sensing axis is perpendicular to the first sensing axis.

3. rotation sensor comprises:

One pedestal;

One wheel hub that extends out from pedestal;

First cover is formed at the drive electrode on the pedestal;

One is installed on the driving element on the wheel hub, be formed with the second cover drive electrode corresponding above it with the first cover drive electrode, pedestal and driving element are arranged to face with each other, the appropriate section of the first and second cover electrodes is staggered on angle each other, thereby electric signal puts on first and second covers and can produce torque on the electrodes on driving element, and this torque makes driving element produce whirling vibration around driving axis in a plane;

One sensing part, it has:

One is installed on the external support ring on the driving element, thereby the whirling vibration of driving element can be delivered to sensing part, sensing part also has a sensing element and an a pair of torque rod that is connected between external support ring and the sensing element in sustained ring, and this is to the torque rod alignment and determine output sensing axis; And

Be used to produce as sensing part around the function of the amplitude of output sensing axis, expression winds the device perpendicular to the signal of the input speed of an axis of driving axis and sensing axis.

4. rotation sensor as claimed in claim 3 is characterized in that, also comprises:

One is formed at first metalized portion on the driving element; And

One is formed at second metalized portion on the sensing element, and first and second metalized portion form a capacitor, and its electric capacity depends on that sensing element winds the rotating speed perpendicular to an axis of driving axis and sensing axis.

5. rotation sensor as claimed in claim 4 is characterized in that, also have be connected in first and second metalized portion, be used for applying feedback torque so that the angular oscillation of output is zero and sensing element is remained in the device of zero position to sensing element.

6. rotation sensor as claimed in claim 4 is characterized in that, also comprises:

Be used for applying ω to the first and second cover drive electrodes _DThe vibration electric signal of/2 frequencies, thus make driving element with driving frequency ω _DThe device of mechanical vibration, wherein sensing element is made its frequency of natural vibration around torque rod and is different from driving frequency ω _D, thereby sensor can be with operate in open loop state;

Be used for driving frequency ω _DDevice following restituted signal, that represent electric capacity between the metalized portion.

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