CN105785074B - A kind of inertial sensor capacitance detecting accelerometer - Google Patents
A kind of inertial sensor capacitance detecting accelerometer Download PDFInfo
- Publication number
- CN105785074B CN105785074B CN201610105474.1A CN201610105474A CN105785074B CN 105785074 B CN105785074 B CN 105785074B CN 201610105474 A CN201610105474 A CN 201610105474A CN 105785074 B CN105785074 B CN 105785074B
- Authority
- CN
- China
- Prior art keywords
- digital
- signal
- output
- digital converter
- floating point
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01P—MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION, OR SHOCK; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT
- G01P15/00—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration
- G01P15/02—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration by making use of inertia forces using solid seismic masses
- G01P15/08—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration by making use of inertia forces using solid seismic masses with conversion into electric or magnetic values
- G01P15/125—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration by making use of inertia forces using solid seismic masses with conversion into electric or magnetic values by capacitive pick-up
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Gyroscopes (AREA)
- Analogue/Digital Conversion (AREA)
Abstract
The present invention provides a kind of inertial sensor capacitance detecting accelerometer, the signal output of input terminal connection inertia detecting element including preamplifier, the output signal of the input terminal connection preamplifier of transient floating point analog-digital converter, the output digit signals of transient floating point analog-digital converter transfer to digital loop filters, then by a quantizer output digit stream, close loop maneuver is realized by electrostatic force feedback unit.Negative-feedback is realized using oversampling technique, improves the linearity, the dynamic accuracy of closed-loop system.The application of digital loop filters realizes the shaping of quantizing noise, achievees the purpose that low noise, digital output.Loop filter is realized using digital form, the integral saturated phenomenon that analog loop filter can be avoided to generate, while the noise of layout design difficulty and analog loop filter is reduced to systematic influence.The accelerometer is quantified using transient floating point analog-digital converter, can effectively improve the noiseproof feature of system.
Description
Technical field
The invention belongs to inertial sensor detection technique fields, and in particular to a kind of inertial sensor capacitance detecting acceleration
Meter.
Background technology
Inertial sensor generally comprises the Sensitive Apparatuses such as accelerometer and gyroscope, these inertia devices are by external force
When effect, corresponding movement is will produce, needs measurement sensor relative to letters such as the speed of Reference and acceleration
Breath.It is illustrated by taking MEMS (Micro-Electro-Mechanical System) accelerometer as an example.Accelerate relative to tradition
Wave detector is spent, mems accelerometer has small, at low cost, high sensitivity, the advantages such as is easily integrated, while when close loop maneuver
Have many advantages, such as that dynamic range is big, the linearity is good high with bandwidth, it is general that this makes it will be used wider and wider, such as in automobile, intelligence
The fields such as energy mobile phone, drilling prospection.In the method for mems accelerometer signal detection, capacitance detecting is a kind of main detection
Means have the characteristics that low noise, low-temperature coefficient and high sensitivity.
Mems accelerometer can be equivalent to a pair of of differential capacitance, and extraneous acceleration makes mems accelerometer mass block produce
Raw displacement, and the variation of displacement is equivalent to capacitance variations.Capacitance detecting needs dedicated reading circuit to handle capacitance signal, existing
Technology mainly detects MEMS capacitance change signals using switching capacity interface circuit.Switching capacity interface detection circuit is main
Including modules such as preamplifier, loop filter and electrostatic force feedbacks, closed-loop control is realized by electrostatic force feedback, it can be with
Reach good linear and dynamic range.Accelerometer capacitance measurement technique mainly uses sigma-delta frameworks, that is, senses
The capacitance signal of device is converted into voltage signal by preamplifier, is then adjusted by analog loop filter and passes through one
Quantizer output bit flow realizes closed-loop control finally by electrostatic force feedback.It is influenced by interface circuit electronic noise, especially
Preamplifier and the limitation of loop filter noise level, the current noise water of above-mentioned sigma-delta interface circuits framework
It puts down in the left and right 1ug/rt (Hz), it is difficult to meet highly sensitive demand.In above-mentioned sigma-delta frameworks, loop filter mesh
It is preceding main using analog form realization, ASIC (Application Specific Integrated Circuit) domain is set
Meter require it is relatively high, such as parameter matching require.In addition, during ASIC design is with realizing, due to device technology error etc.
The modules such as factor, preamplifier and loop filter will produce offset voltage, and offset voltage can cause integrator to generate product
Divide saturation.The design parameter that desired test obtains system module in practice is relatively difficult, especially test loop filter parameter,
Currently without very accurate means of testing.
In addition, solve the above problems may be used simple analog-digital converter (ADC) by preamplifier output signal into
Row is quantified and is filtered using digital form, needs to consider that ADC generates influence of the quantizing noise to system closed loop noise at this time.
In order to reduce influence of the ADC quantizing noises to system noise performance, effective method is to use high-precision adc.In close loop maneuver
When, due to electrostatic force, MEMS mass blocks are moved up and down in equilbrium position substantially so that MEMS Sensitive Apparatus output signals accord with
Normal distribution is closed, and then the voltage signal of preamplifier output also complies with normal distribution.Using high-precision adc although reducing
Quantizing noise, but the number of significant digit actually used when closed loop is extremely limited, certainly will thus generate the wasting of resources, increase and set
Cost and design complexities are counted, industrialization use is unfavorable for.
Invention content
In order to solve the above technical problem, the present invention provides a kind of inertial sensor capacitances to examine accelerometer, realizes height
Precision and numeral output.Simple ADC amounts are effectively reduced while meeting normal distribution application using transient floating point analog-digital converter
Changing noise influences system noise.
Technical solution provided by the invention is：A kind of inertial sensor capacitance detecting accelerometer, the acceleration
Meter includes：
MEMS capacitance Digital Detecting units, the MEMS capacitances Digital Detecting unit is for experiencing acceleration signal, by institute
It states acceleration signal and is converted into the identifiable digital input signals of digital arithmetic unit.
Digital arithmetic unit, the digital arithmetic unit carry out digital input signals at phase compensation and noise shaping
Reason, and carry out quantized digital signal and generate electrostatic force feedback unit required input signal.
Electrostatic force feedback unit, the electrostatic force feedback unit convert digital arithmetic unit output signal to electrostatic force,
For balancing the inertia force.
The MEMS capacitances Digital Detecting unit includes a preamplifier；
Further, the preamplifier is used to detect the capacitance signal of inertia detecting element output and is converted into instantaneous
The identifiable voltage signal of floating-point analog-to-digital converter；
Further, the preamplifier has used a kind of simple and practical Correlated Double Sampling, can realize difference
Divide amplification, reduce offset voltage, and include sampling holder buffer, increases carrying load ability；
Further, the preamplifier includes a kind of feedback control switch, can under with reference also to voltage condition,
Realize the output of maximum electrostatic power.Time-sharing multiplex can be completed by timing control simultaneously, reduce electrode demand, increase to greatest extent
Power up capacity.
The MEMS capacitances Digital Detecting unit further includes an instantaneous floating-point analog-to-digital converter；
Further, the transient floating point analog-digital converter can quantify input signal, and it is defeated to generate digital signal
Go out, is converted into the input signal that digital loop filters can identify；
Further, the transient floating point analog-to-digital conversion device includes a kind of temporal gain controller, for judging input letter
Gain ranging where number；
Further, the transient floating point analog-digital converter also includes a kind of linear quantizer, can be according in the increasing
Equal interval quantizing, and output data code stream are carried out to input signal in beneficial range；
Further, the transient floating point analog-digital converter further includes a kind of Serial output or parallel output encoder,
For generating transient floating point analog-digital converter output code flow；
Further, the transient floating point analog-digital converter can either meet the function of simple analog-digital converter, can also accord with
The characteristics of mems accelerometer output signal meets normal distribution is closed, design complexities and design cost are reduced.
The digital arithmetic unit includes a digital loop filters and a quantizer；
Further, the digital loop filters carry out phase compensation and noise in close loop maneuver to input signal
Shaping；
Further, the realization of the frameworks such as PD, PID may be used in digital loop filters, while realizing that over-sampling is handled；
Further, a quantizer quantifies the digital signal that digital loop filters export, output one
Position data code flow, and it is converted into the input signal that electrostatic force feedback unit can identify.
Further, a data code stream of the quantizer output includes the feedback needed for electrostatic force feedback unit
Power size and polarity information, while including input acceleration information.
The a data code stream that the electrostatic force feedback unit can be exported according to loop filter, is converted into electrostatic force,
It acts on inertial sensor, for balancing the inertia force, realizes close loop maneuver.
Further, the MEMS sensing units, preamplifier, the transient floating point analog-digital converter, described
Digital loop filters, a quantizer, the electrostatic force feedback unit are sequentially connected, and constitute closed circuit.
A kind of inertial sensor capacitance detecting accelerometer feedback, described method includes following steps：
MEMS capacitance Digital Detecting units are provided, the MEMS capacitances Digital Detecting unit is used to experience acceleration signal,
The analog acceleration signal, which is converted to digital signal, becomes the input signal that digital arithmetic unit can identify；
Digital arithmetic unit is provided, the digital arithmetic unit converts the output signal of MEMS capacitance Digital Detecting units
For the identifiable input signal of electrostatic force feedback unit；
Electrostatic force feedback unit is provided, the electrostatic force feedback unit converts the input signal to electrostatic force for putting down
Weigh the inertia force.
Further, the MEMS capacitances Digital Detecting unit provides a preamplifier, by the electricity of MEMS sensing units
Hold signal and is converted into voltage signal；
Further, the capacitance Digital Detecting unit also provides an instantaneous floating-point analog-to-digital converter, by preamplifier
Output analog signal is converted into digital signal, the input signal as digital arithmetic unit；
Further, the digital arithmetic unit provides digital loop filters and carries out phase compensation to input digital signal
And noise shaping；
Further, the digital arithmetic unit also provides a quantizer and believes the number that digital loop filters export
Number quantified, exports a data code stream；
Further, a data code stream that the electrostatic force feedback unit can be exported according to digital arithmetic unit, turns
Electrostatic force is turned to, is acted in inertia detection unit, inertia force caused by equilibrium electrostatic power.
Beneficial effects of the present invention are：The output capacitance of inertia detecting element is believed using simple Correlated Double Sampling
Number it is converted into voltage signal, the analog signal that preamplifier exports then is converted by number by transient floating point analog-digital converter
Word signal, and digital loop filters is transferred to carry out noise shaping, there is no integral saturated phenomenons.The preamplifier uses phase
Imbalance electricity can effectively be reduced by closing double-sampling, while provide feedback control switch, can realize that maximum electrostatic power exports.This
Outside, integral saturated phenomenon can be effectively avoided using digital loop filters, reduces design difficulty and design cost, be conducive to quick
Optimal Filter parameter saves design time.Finally, transient floating point analog-to-digital conversion device provided by the invention can be believed according to input
Number size determine gain ranging, in specific gain ranging, carry out equal interval quantizing, while reducing quantization error both
It reduces to simple analog-digital converter accuracy requirement, and eliminates the non-linear and design of non-uniform quantizing analog-digital converter generation
The problems such as complicated, and then system noise performance can be improved, realize digitlization and high-precision.
Description of the drawings
Fig. 1 is a kind of typical " sandwich " structure MEMS acceleration sensor structure schematic diagrames；
Fig. 2 is the MEMS acceleration transducer capacitance detecting accelerometer frameworks of the prior art；
Fig. 3 is inertial sensor capacitance detecting accelerometer framework of the present invention；
Fig. 4 is preamplifier architectures schematic diagram；
When Fig. 5 (a) is that acceleration signal inputs for 0.001g, mems accelerometer output signal distribution histogram；Fig. 5
(b) be acceleration signal be 0.011g input when, mems accelerometer output signal distribution histogram；Fig. 5 (c) is acceleration letter
Number for 0.101g input when, mems accelerometer output signal distribution histogram；Fig. 5 (d) is that acceleration signal is that 0.201g is defeated
It is fashionable, mems accelerometer output signal distribution histogram；
Fig. 6 is transient floating point analog-digital converter structure schematic diagram；
Fig. 7 is transient floating point analog-digital converter work flow diagram；
Fig. 8 is 3-bit transient floating points analog-digital converter and the simple modulus converter quantizing noise comparison diagrams of 4-bit；
Fig. 9 is third-order digital loop filter open-loop transfer function Bode diagram；
When Figure 10 is 8-bit transient floating point analog-to-digital conversion devices, five rank system output signal PSD figures.
Specific implementation mode
In order to make the purpose , technical scheme and advantage of the present invention be clearer, with reference to the accompanying drawings and embodiments, right
The present invention is explained in further detail.It should be appreciated that specific embodiment described herein is used only for explaining the present invention, and
It is not used in the restriction present invention.
On the contrary, the present invention covers any replacement done in the spirit and scope of the present invention being defined by the claims, repaiies
Change, equivalent method and scheme.Further, in order to make the public have a better understanding the present invention, below to the thin of the present invention
It is detailed to describe some specific detail sections in section description.Part without these details for a person skilled in the art
Description can also understand the present invention completely.
With reference to figure 3, which is one schematic diagram of inertial sensor capacitance detecting accelerometer embodiment provided by the invention.This
" sandwich " MEMS inertial sensor detecting element is embedded into a high-order sigma-delta (SDM) by the system architecture of invention
In the middle, by rational circuit design, system stability design, digital feedback is realized.It is realized as a result of oversampling technique
Negative-feedback greatly improves the linearity, dynamic range of closed-loop system etc..In addition, the application of high-order SDM realizes digital noise
Shaping and phase compensation achieve the purpose that low noise, numeral output.
The present embodiment provides inertial sensor capacitance detecting accelerometers, including：Inertia detection unit 1, preamplifier
2, transient floating point analog-digital converter 3,4, quantizers 5 of digital loop filters and electrostatic force feedback unit 6, the inertia
Detection unit 1 is MEMS sensing units.
With reference to figure 4, the preamplifier 2 includes three electrodes to connect with three pole plates of inertial sensor：VT, VC and
VB, wherein VT connection sensor top crown electrode, VC connection sensor middle plates, VB connection sensor bottom crowns；On pole plate
Three voltages connected：+ Vfre ,-Vref and VCOM, wherein+Vref is reference voltage ,-Vref is negative reference voltage,
VCOM is common-mode voltage；Three of sensor are attached between electrode and reference voltage by switch S1~S7；Sensor
Target is connect by switch S8 with amplifier Amp1；Switch S9~S11 control Amp1 signals read and reset；Switch S12
It is sampling switch；Capacitance Cf is feedback capacity, the gain size of control amplifier Amp1；Capacitance Csample is sampling capacitance, with
Switch S12 constitutes sample circuit；Amplifier Amp2 is unit gain driver, increases the output loading capability of preamplifier 2；
Clock control signal ph1 and ph2/ph3 is non-overlapping clock, the connecting and disconnecting of control switch S1~S12.
With reference to figure 5, shown histogram is produced in different acceleration signals according to inertial sensor detection unit 1
The corresponding histogram distribution of raw output signal, it can be seen that under varying input signal, output histogram substantially conforms to normal state
Distribution lays the foundation for the proposition of transient floating point analog-digital converter 3 with demand.
With reference to figure 6, the transient floating point analog-digital converter 3 includes temporal gain controller 31, can be according to input signal
Amplitude, judge gain section, control quantizer 32 quantifies step size；Quantizer 32 is according to transient floating point analog-digital converter 3
Adjust automatically quantifies step size, and different numerical digit stream is quantified as according to varying input signal；Serial/parallel encoder 33 is by wink
When gain controller 31 generation the liner code that generates of gain code and quantizer 32 be combined into transient floating point analog-digital converter 3 with
The corresponding digital output signal of input signal.
With reference to figure 9, the amplitude-frequency of the digital loop filters 4 is corresponding, is made of multiple-order integrator, such as quadravalence, five ranks, six
Rank SDM introduces 2,3,4 integrators respectively.When integrator number is 3, then adding inertial sensor detecting element
1 approximate second integrator, we term it five rank SDM.
We are reference with " sandwich " structure inertia accelerometer below, as shown in Figure 1, dividing in detail in conjunction with the derivation of equation
Analyse the operation principle of accelerometer provided by the invention.
It is same as the prior art, it is corresponding upper and lower when mass block 100 is subjected to displacement x in accelerometer shown in Fig. 1
Plates capacitance difference Δ c is：
Wherein, A is polar plate area, d primary clearances between pole plate, C0Corresponding initial capacitance, ε are when static for sensor
Dielectric constant.As x ＜ ＜ d, and when x ≈ 0, there are Δ c ≈ 2Cox/d.As can be seen that under certain condition, capacitance change and position
It is in a linear relationship to move variation.
In preamplifier 2 shown in Fig. 4, control clock signal ph1 and ph2/ph3 are two-phase non-overlapp-ing clocks, point
Imbalance Wan Cheng not inputted and be stored and read out process.In the ph1 stages, switch S1 is disconnected, and switch S2 meets reference voltage+Vref, opens
It closes S3 and meets negative reference voltage-Vref, switch S4~S8 is disconnected, and switch S9 is connected, and switch S10 is disconnected, and switch S11 connects common-mode voltage
VCOM, switch S12 are disconnected.In the ph1 stages, in conjunction with above-mentioned switching manipulation, the offset voltage of preamplifier 2 is stored in feedback and increases
On beneficial capacitance.Negative reference voltage-Vref is met in ph2/ph3 stage switches S1, switch S2 is disconnected, and switch S3 is disconnected, and switch S4 connects
Reference voltage+Vref, switch S5~S7 are disconnected, and switch S8 connects sensor middle plate electrode Vc, and switch S9 is disconnected, switch
S10 is connected, and switch S11 is disconnected, and switch S12 offsets output signal VX and connection sampling capacitance and unit gain driver
It completes to read while the offset voltage that the ph1 stages store.Sample circuit with unit gain driver Amp2 is put to reduce
The noise of big device Amp1 output signals and the carrying load ability for increasing Amp1.It, can after the completion of ph1 the and ph2/ph3 stages
It converts the capacitance change signal of sensor to voltage signal, by charge conservation, capacitance caused by acceleration change can be obtained and become
Change Δ c and the relational expression of reading circuit output voltage is as follows：
V in above formulaxIt is the output signal of amplifier Amp1, VrefFor reference voltage, CfFor feedback oscillator capacitance.It can be seen that
As x ＜ ＜ d, and when x ≈ 0, convolution (1) above formula is equivalent to：
It can obtain, in x ＜ ＜ d, and 2 read-out voltage of preamplifier causes with acceleration change in the present invention when x ≈ 0
Displacement change approximately linear relationship.Differential capacitance is utilized in this preamplifier 2 simultaneously so that and gain doubles,
A kind of simple and effective Correlated Double Sampling is used simultaneously, can effectively offset influence of the offset voltage to system.In addition, adopting
Sample retainer can reduce system noise and increase by 2 carrying load ability of preamplifier.
In histogram shown in fig. 5, what type of analog-digital converter is introduced in order to study, is reached with minimum cost
Obtain best system performance purpose.In fig. 5 it can be seen that when input 125Hz acceleration signal when, signal amplitude from
When 0.001g to 0.201g, the distribution histogram base of prior art such as 2 output signal of corresponding preamplifier in Fig. 2
Originally meet normal distribution.Therefore it needs to consider under the premise of not increasing system complexity using the suitable analog-digital converter amount of progress
Change, achievees the effect that improve system performance.In prior art such as Fig. 2, a kind of mode is to use simple analog-digital converter
Quantization is completed, but in order to achieve the purpose that reduce quantizing noise, needs to use high-precision adc, is bound to cause resource
Waste increases design cost.Another mode is to use non-uniform quantizing analog-digital converter, i.e., the signal being distributed around to zero
It is individually handled, is non-uniform quantizing in entire input reference signal, although more simple analog-to-digital conversion device is to system performance
It makes moderate progress, but nonlinear analog-to-digital converter implements more complex and very high to design requirement, while amount of nonlinearity
Change introduce it is non-linear the problems such as system performance certainly will be had an impact.For this purpose, the present invention proposes that a kind of transient floating point modulus turns
Parallel operation 3 designs to complete digital accelerometer system.
It is the structure chart of the transient floating point analog-digital converter 3, including temporal gain controller 31, quantizer shown in Fig. 6
32 and serial/parallel encoder 33.Temporal gain controller 31 can be according to the range adjust quantization device 32 of input signal
Reference voltage, quantizer 32 select reference voltage level according to the reference voltage control signal that temporal gain controller 31 is sent out, and
Complete equal interval quantizing.Serial/parallel encoder 33 is to export gain code and quantizer 32 that temporal gain controller 31 exports
Liner code be integrated into output signal, transfer to following digital loop filter 4 handle.
Fig. 7 show 3 work flow diagram of transient floating point analog-digital converter of the present invention.Transient floating point analog-digital converter 3 it is defeated
Enter the output signal that signal is preamplifier 2.So-called transient floating point, which refers to this n-bit ADC, to be predicted to a certain extent
Input signal size, and reference source voltage swing is adjusted according to input signal, it is big to reach big signal quantization error, small signal quantization
Error is small, realizes (n+1) bits or higher resolution ratio.When input signal amplitude is more than Vref/2, reference voltage is kept
Vref is constant, is quantified according to LSB3 and exports corresponding digital code；When input signal amplitude is in Vref/2 and Vref/, 4 it
Between when, adjustment reference voltage is Vref/2, and carrying out quantization according to LSB2 exports corresponding digital code；When input signal amplitude is less than
When Vref/4, reference voltage is changed into Vref/4, simultaneously output digit signals quantify according to LSB3, and so on, it can
To determine the value of gain voltage according to actual demand, that is, realize that small signal quantization noise is small, big signal quantization noise is big.With list
Pure analog-digital converter is compared with non-homogeneous analog-digital converter, while transient floating point analog-digital converter 3 of the present invention realizes quantization its
Quantization code is uniform quantization in selected gain ranging, can effectively reduce to simple modulus converter accuracy requirement with avoid it is non-
The problem that uniform analog-digital converter non-uniform quantizing, realization is simpler, reduces Design of A/D Converter complexity.Figure
It is that comparison uses 3-bit transient floating point analog-digital converters 3 of the present invention and simple 4-bit analog-digital converters quantizing noise shown in 8, it can
To find out, heart district domain in the signal, the amount of the quantizing noise and 4-bit analog-digital converters of 3-bit transient floating points analog-digital converter 3
It is suitable to change noise.
Fig. 9 is the amplitude-frequency response for the digital loop filters 4 that the present invention uses.Digital loop filters 4 have many differences
Framework, but mentality of designing is much the same.For there are the topological structures of resonance point, improving condenser type from the angle of energy adds
The quantized noise shaping ability of speedometer, that is, by quantizing noise from working frequency range " digging " to high band, the position of resonance point
Set the position for determining and being walked quantizing noise energy by " digging ".Loop filter is made of multiple-order integrator, and transmission function can be with
It is expressed as：
H (z)=n (1-z-1)n (4)
Wherein n is integrator exponent number.When n is 3, in addition the approximate second-order integrator of inertial sensor detecting element, claims
Be five rank SDM.For traditional SDM, the signal-to-noise ratio of system output is：
SQNRN=6+10log (2N+1)+10log (2N+1) log (OSR) -10N (5)
As can be seen that signal-to-noise ratio is related to the exponent number of integrator, over-sampling rate.Acceleration sensitive device is embedded into
In SDM, signal can also be with reference to above formula to the signal-to-noise ratio of quantizing noise.
4 output signal of digital loop filters generates numeral output code stream by a quantizer, according to the digital code stream
Positive-negative relationship judge the direction of electrostatic force feedback size and electrostatic force feedback, by switch S5 shown in Fig. 4 and switch S6 into
Row feedback control completes close loop maneuver.Feedback force is enabled to be doubled in same time using switch S5 and switch S6, i.e., in fact
Existing electrostatic force output maximizes.
Result above is preposition it can be shown that in inertial sensor capacitance detecting accelerometer provided in an embodiment of the present invention
Amplifier 2 uses simple Correlated Double Sampling, is improving the accelerometer voltage conversion gain using differential capacitive structure
While can effectively reduce influence of the input offset voltage to system of preamplifier 2.Using 4 energy of digital loop filters
It is enough effectively to overcome the problems such as integral is saturated, complex circuit designs and parameter testing are difficult present in prior art.In addition, this
The involved transient floating point analog-digital converter 3 of invention can while meeting the quantization function for realizing simple analog-digital converter
Meet the characteristics of acceleration sensor outputs signals meet normal distribution, also the non-uniform quantizer of use can be overcome to be brought
Non-linear factor influence, realize fairly simple, reduce design complexities and design cost.According to Figure 10 when the present invention uses
When 8-bit transient floating point analog-digital converters 3, system noise levels disclosure satisfy that high precision design demand.
Inertial sensor capacitance detecting accelerometer provided by the invention can also be applied to differential capacitive structure
Other inertia detecting elements are such as MEMS gyroscope.
The above described is only a preferred embodiment of the present invention, being not intended to limit the present invention in any form.Though
So the present invention has been disclosed with preferred embodiment as above, and however, it is not intended to limit the invention.Any technology for being familiar with this field
Personnel, without departing from the scope of the technical proposal of the invention, all using the methods and technical content of the disclosure above to this hair
Bright technical solution makes many possible changes and modifications, or is revised as the equivalent embodiment of equivalent variations.Therefore, every not take off
Content from technical solution of the present invention, according to the technical essence of the invention it is made to the above embodiment it is any it is simple modification, etc.
With variation and modification, still fall within technical solution of the present invention protection in the range of.
Claims (7)
1. a kind of inertial sensor capacitance detecting accelerometer, which is characterized in that the accelerometer includes MEMS capacitance numbers
Detection unit, digital arithmetic unit and electrostatic force feedback unit, the MEMS capacitances Digital Detecting unit, digital arithmetic unit and
Electrostatic force feedback unit is sequentially connected and constitutes circuit；
The MEMS capacitances Digital Detecting unit before an instantaneous floating-point analog-to-digital converter, a MEMS sensing units and one including putting
Big device；The MEMS sensing units are converted into capacitance signal for detecting extraneous acceleration signal, as preamplifier
Input signal；The preamplifier receives MEMS sensing units output signal and is converted into voltage signal output as instantaneous floating
The input signal of point analog-digital converter；Transient floating point analog-digital converter quantifies the voltage signal of input, generates number letter
Number output；
The digital arithmetic unit includes a digital loop filters and a quantizer；The digital loop filters will come from
The digital signal of transient floating point analog-digital converter carries out noise shaping；What one quantizer exported digital loop filters
Digital signal is quantified, and a data code stream is exported；
The a data code stream that the electrostatic force feedback unit is exported according to a quantizer, is converted into electrostatic force, acts on
MEMS sensing units.
2. a kind of inertial sensor capacitance detecting accelerometer according to claim 1, which is characterized in that put before described
Big device uses double-sampling, converts output signal to the identifiable input signal of transient floating point analog-digital converter.
3. a kind of inertial sensor capacitance detecting accelerometer according to claim 1, which is characterized in that described instantaneous floating
Point analog-digital converter includes an instantaneous gain controller, a Serial output or parallel output encoder；The temporal gain control
Device is for gain ranging where judging input signal；The Serial output or parallel output encoder are for generating transient floating point mould
Number converter output code flow.
4. a kind of inertial sensor capacitance detecting accelerometer according to claim 1, which is characterized in that the one digit number
Include feedback force size and polarity information needed for electrostatic force feedback unit according to code stream, while including input acceleration information.
5. a kind of feedback of inertial sensor capacitance detecting accelerometer as described in claim 1, which is characterized in that
Experience acceleration signal using MEMS sensing units, the acceleration signal is converted into capacitance signal；Preamplifier receives
The capacitance signal of MEMS sensing units output is simultaneously converted into voltage signal；Transient floating point analog-digital converter believes the voltage
Number be converted to digital signal；Digital signal is carried out noise shaping processing by digital loop filters；One quantizer is by digital rings
The digital signal of path filter output is quantified, and a data code stream is exported；Electrostatic force feedback unit is by a data
Code stream is converted into electrostatic force, acts on MEMS sensing units, balances corresponding inertia force.
6. feedback according to claim 5, which is characterized in that the transient floating point analog-digital converter includes one
Temporal gain controller, a Serial output or parallel output encoder；The temporal gain controller is for judging input signal
Place gain ranging；The Serial output or parallel output encoder are for generating transient floating point analog-digital converter output code flow.
7. feedback according to claim 5, which is characterized in that a data code stream includes that electrostatic force is anti-
The feedback force size and polarity information needed for unit are presented, while including input acceleration information.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610105474.1A CN105785074B (en) | 2016-02-25 | 2016-02-25 | A kind of inertial sensor capacitance detecting accelerometer |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610105474.1A CN105785074B (en) | 2016-02-25 | 2016-02-25 | A kind of inertial sensor capacitance detecting accelerometer |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN105785074A CN105785074A (en) | 2016-07-20 |
| CN105785074B true CN105785074B (en) | 2018-07-20 |
Family
ID=56403030
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201610105474.1A Active CN105785074B (en) | 2016-02-25 | 2016-02-25 | A kind of inertial sensor capacitance detecting accelerometer |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN105785074B (en) |
Families Citing this family (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106526234B (en) * | 2016-09-30 | 2018-12-21 | 中国科学院地质与地球物理研究所 | A kind of Inertial Sensor System based on sigma-delta closed-loop control |
| CN107290566B (en) * | 2017-07-17 | 2023-06-23 | 四川知微传感技术有限公司 | Basic capacitance compensation circuit for digital accelerometer |
| CN107192851B (en) * | 2017-07-17 | 2023-05-26 | 四川知微传感技术有限公司 | Capacitance detection system of charge modulator accelerometer |
| CN108255108B (en) * | 2018-01-24 | 2019-06-04 | 中国科学院地质与地球物理研究所 | A kind of MEMS sensor controller circuitry |
| CN110350905B (en) * | 2018-04-03 | 2024-04-19 | 中国科学院声学研究所 | MEMS capacitive accelerometer interface circuit |
| CN111399369A (en) * | 2020-02-20 | 2020-07-10 | 西北工业大学 | Digital closed-loop control method for photoelectric accelerometer sensor |
| CN112187271B (en) * | 2020-10-21 | 2021-12-07 | 中国科学院地质与地球物理研究所 | MEMS sensor system and use method thereof |
| CN112234987A (en) * | 2020-10-21 | 2021-01-15 | 中国科学院地质与地球物理研究所 | MEMS sensor system and use method thereof |
| CN113092820A (en) * | 2021-05-13 | 2021-07-09 | 中国科学院地质与地球物理研究所 | High-precision acceleration sensor noise performance analysis method and device |
| CN114777756B (en) * | 2022-06-20 | 2022-09-16 | 中国船舶重工集团公司第七0七研究所 | Resonance gyroscope based on closed-loop control and control method thereof |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102624397A (en) * | 2012-03-22 | 2012-08-01 | 哈尔滨工程大学 | High-linearity fully differential digital micro-accelerometer interface circuit system |
| CN103869098A (en) * | 2014-04-16 | 2014-06-18 | 东南大学 | Silicon micro resonance type accelerometer circuit control system |
| CN104049109A (en) * | 2014-07-07 | 2014-09-17 | 湘潭大学 | Servo reading circuit of MEMS acceleration sensor |
| CN104579344A (en) * | 2013-10-18 | 2015-04-29 | 亚德诺半导体集团 | Multi-stage noise shaping analog-to-digital converter |
| CN104980154A (en) * | 2014-04-07 | 2015-10-14 | 亚德诺半导体集团 | Estimation of digital-to-analog converter static mismatch errors |
| CN105301284A (en) * | 2015-10-30 | 2016-02-03 | 哈尔滨工程大学 | Low-power digital accelerometer interface circuit system |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US9030342B2 (en) * | 2013-07-18 | 2015-05-12 | Analog Devices Global | Digital tuning engine for highly programmable delta-sigma analog-to-digital converters |
-
2016
- 2016-02-25 CN CN201610105474.1A patent/CN105785074B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102624397A (en) * | 2012-03-22 | 2012-08-01 | 哈尔滨工程大学 | High-linearity fully differential digital micro-accelerometer interface circuit system |
| CN104579344A (en) * | 2013-10-18 | 2015-04-29 | 亚德诺半导体集团 | Multi-stage noise shaping analog-to-digital converter |
| CN104980154A (en) * | 2014-04-07 | 2015-10-14 | 亚德诺半导体集团 | Estimation of digital-to-analog converter static mismatch errors |
| CN103869098A (en) * | 2014-04-16 | 2014-06-18 | 东南大学 | Silicon micro resonance type accelerometer circuit control system |
| CN104049109A (en) * | 2014-07-07 | 2014-09-17 | 湘潭大学 | Servo reading circuit of MEMS acceleration sensor |
| CN105301284A (en) * | 2015-10-30 | 2016-02-03 | 哈尔滨工程大学 | Low-power digital accelerometer interface circuit system |
Non-Patent Citations (1)
| Title |
|---|
| 基于Σ-Δ调制技术的微加速度计系统研究;付娟;《中国优秀硕士学位论文全文数据库 工程科技II辑》;20111215(第S2期);第7-66页 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN105785074A (en) | 2016-07-20 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN105785074B (en) | A kind of inertial sensor capacitance detecting accelerometer | |
| CN105759077B (en) | A kind of novel high-precision mems accelerometer | |
| US10309984B2 (en) | High-precision pendulous accelerometer | |
| TWI585368B (en) | Method for reducing non-linearity during measurement of a physical parameter and electronic circuit for implementing the same | |
| CN104049109B (en) | A kind of MEMS acceleration transducer servo sensing circuit | |
| CN104168020B (en) | The electric capacity gamma correction circuit and method of a kind of analog-digital converter of approach type by turn | |
| JPH06265417A (en) | Force-measuring device | |
| CN109669054B (en) | High-precision fully-differential capacitor-voltage conversion circuit system | |
| CN105785075B (en) | A kind of condenser type inertial sensor digital servo circuit | |
| CN105758402A (en) | Closed-loop detection system of silicon micromachined gyro | |
| EP2966456A1 (en) | Electronic measurement circuit for a capacitive sensor | |
| Zhong et al. | Correlated double amplifying readout technique for low-noise power-efficient MEMS capacitive accelerometer | |
| Zhao et al. | A high-voltage closed-loop SC interface for a±50 g capacitive micro-accelerometer with 112.4 dB dynamic range | |
| Zhong et al. | Voltage control ratiometric readout technique with improved dynamic range and power-efficiency for open-loop MEMS capacitive accelerometer | |
| CN115184639A (en) | Closed-loop reading circuit of triaxial MEMS accelerometer | |
| JP6042003B2 (en) | Electronic measurement circuit | |
| CN103018485B (en) | Mass block electrostatic force feedback based linearization circuit in application specific integrated circuit (ASIC) chip of sigma-delta micro-accelerometer interface | |
| EP2684292A1 (en) | Method for using a sensor system having a single-bit quantizer and a multi-bit feedback loop | |
| Li et al. | Design of a Novel Self-Test-on-Chip Interface ASIC for Capacitive Accelerometers | |
| CN111561958B (en) | MEMS sensor detection device and MEMS sensor system | |
| CN210198392U (en) | Novel MEMS resonant gyroscope measurement and control device | |
| Jun et al. | A 16 bit incremental ADC with swapping DAC for low power sensor applications | |
| CN114509579A (en) | MEMS capacitive accelerometer interface circuit adopting voltage control proportion reading technology | |
| Li et al. | Design of a high precision digital interface circuit for capacitive MEMS accelerometers with floating point ADC | |
| Wang et al. | A method to reduce harmonic distortion of MEMS accelerometer |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |