CN106289218A - A kind of gyroscope testing circuit, gyroscope and electronic equipment - Google Patents

Abstract

A gyroscope detection circuit, gyroscope and electronic equipment are used to solve the problem that the performance of the gyroscope is restricted by the quadrature error signal in the gyroscope. The detection circuit includes: a first amplifier, whose input end is connected with the output end of the sensitive mode signal of the gyroscope; a second amplifier, whose input end is connected with the output end of the driving mode signal of the gyroscope; The output signal of the second amplifier is multiplied by the coefficient signal as the output of the multiplier, and the phase of the output signal is the same as the phase of the driving mode signal; the subtractor, the first input end of the subtractor is connected with the output end of the first amplifier, and the subtractor The second input end of the multiplier is connected to the output end of the multiplier, and is used to subtract the signal at the second input end from the signal at the first input end as the output of the subtractor; wherein, when the coefficient signal of the multiplier is the first coefficient signal, the subtraction Among the signals output by the device, the amplitude of the signal with the same phase as the driving mode signal is less than or equal to the set threshold.

Description

A gyroscope detection circuit, gyroscope and electronic equipment

technical field

The invention relates to the field of electronic technology, in particular to a gyroscope detection circuit, a gyroscope and electronic equipment.

Background technique

Micro-Electro-Mechanical System (MEMS for short) gyroscopes have the advantages of small size, light weight, low power consumption, and easy digitization, and are widely used in civil and national defense fields.

The most widely used MEMS gyroscope is the vibrating gyroscope. The vibrating gyroscope mainly uses the Coriolis force to convert the input angular velocity into displacement, and then detects the displacement by means of voltage or piezoelectricity. The amount of applied angular velocity is proportional, therefore, the angular velocity can be determined by detecting the change in capacitance value.

Specifically, referring to Fig. 1, it is a schematic diagram of a simplified model of a micromechanical gyroscope. Under the drive of the excitation voltage, the mass m vibrates reciprocatingly along the X-axis direction (called: the driving direction), which is called the driving mode. Capacitors with perpendicular directions can detect the change of capacitance value, and then output the driving mode signal, and the amplitude of the mass block in the driving direction can be determined according to the driving mode signal. When an external angular velocity around the Z-axis is applied, the mass block is subjected to the Coriolis force, which produces vibration in the Y-axis direction (called: sensitive direction), called the sensitive mode, and the capacitance perpendicular to the sensitive direction The change of the capacitance value can be detected, and then the sensitive mode signal can be output, and the amplitude of the mass block in the sensitive direction can be determined according to the sensitive mode signal, and then the angular velocity value can be determined according to the amplitude in the sensitive direction.

In actual situations, due to factors such as processing accuracy and material residual stress, the driving axis corresponding to the driving direction of the vibrating gyroscope and the sensitive axis corresponding to the sensitive direction cannot be completely perpendicular, resulting in the vibration of the gyroscope in the driving direction will be in the sensitive direction. Therefore, even when there is no angular velocity input, the capacitance in the sensitive direction can still detect the output signal due to the displacement component. This output signal is 90° out of phase with the effective signal produced by the vibration in the detection direction and is therefore called the quadrature error signal.

The quadrature error signal changes with the external environment such as temperature, and is the main error signal of the mechanical coupling of the MEMS gyroscope. It will not only cause the zero drift instability of the system, but also cause the detection circuit to saturate, restricting the performance of the gyroscope.

Contents of the invention

Embodiments of the present invention provide a gyroscope detection circuit, a gyroscope and electronic equipment, which are used to solve the problem that the performance of the gyroscope is restricted by the quadrature error signal in the gyroscope.

In the first aspect, the embodiment of the present invention provides a gyroscope detection circuit, including: a first amplifier, the input end of the first amplifier is connected to the sensitive mode signal output end of the gyroscope; a second amplifier, the second The input end of the amplifier is connected with the output end of the driving mode signal of the gyroscope; the multiplier, the input end of the multiplier is connected with the output end of the second amplifier, and the multiplier is used to connect the second amplifier The output signal of the multiplier is multiplied by the coefficient signal as the output of the multiplier, and the phase of the output signal of the multiplier is the same as the phase of the driving mode signal; The output terminal of an amplifier is connected, the second input terminal of the subtractor is connected with the output terminal of the multiplier, and the subtractor is used to subtract the signal at the first input terminal from the signal at the second input terminal as the The output of the subtractor; wherein, when the coefficient signal of the multiplier is the first coefficient signal, the amplitude of the signal output by the subtractor with the same phase as the driving mode signal is less than or equal to the set threshold.

Optionally, the detection circuit further includes: a first demodulator, the input terminal of the first demodulator is connected to the output terminal of the subtractor, and the first demodulator is used to convert the first In the input signal of the demodulator, the signal with the same phase as the driving mode signal is demodulated into a DC signal, and outputs the DC signal; an error feedback circuit, the input terminal of the error feedback circuit is connected to the first demodulator connected to the output terminal of the multiplier, the output terminal of the error feedback circuit is connected to the second input terminal of the multiplier, and the error feedback circuit is used to adjust the DC signal according to the output of the first demodulator. The coefficient signal of the multiplier, so that the DC signal output by the first demodulator approaches the set threshold.

Optionally, the error feedback circuit includes: a judging unit, the input end of the judging unit is connected to the output end of the first demodulator, and is used to judge the direct current of the output of the first demodulator. Whether the signal is less than or equal to the set threshold; a coefficient adjuster, the input end of the coefficient adjuster is connected to the output end of the judgment unit, and the output end of the coefficient adjuster is connected to the second input end of the multiplier connected, the output value of the coefficient regulator is used as the coefficient signal of the multiplier; wherein, when the DC signal output by the first demodulator is greater than the set threshold, the judgment unit indicates the The coefficient adjuster changes the output value so that the direct current signal output by the first demodulator becomes smaller after the coefficient adjuster changes the output value.

Optionally, the coefficient regulator includes: a digital signal generator, the input end of the digital signal generator is connected to the output end of the judgment unit, and the digital signal generator is used to generate digital signal; a digital-to-analog converter, the input of the digital-to-analog converter is connected to the output of the digital signal generator, and the output of the digital-to-analog converter is connected to the second input of the multiplier, The digital-to-analog converter is used to convert the digital signal output by the digital signal generator into the coefficient signal.

Optionally, the displacement of the first amplifier is equal to the displacement of the second amplifier.

Optionally, the first amplifier and the second amplifier are chopper-stabilized amplifiers.

Optionally, the detection circuit further includes: a phase shifter, the input end of the phase shifter is connected to the output end of the second amplifier, and the phase shifter is used to adjust the phase of the input signal to the sensitive The phase of the modal signal; the second demodulator, the first input end of the second demodulator is connected with the output end of the subtractor, and the second input end of the second demodulator is connected with the shifter The output terminal of the phase shifter is connected, and the second demodulator is used to demodulate the signal of the same phase as the sensitive mode signal in the input signal of the second demodulator according to the output signal of the phase shifter for a DC signal.

In the second aspect, an embodiment of the present invention provides a gyroscope, including: a driving circuit for generating a driving voltage; a vibration sensor, the input end of the vibration sensor is connected to the output end of the driving circuit, The driving voltage vibrates, the first output end of the vibration sensor is used to output the sensitive mode signal of the gyroscope, and the second output end of the vibration sensor is used to output the driving mode signal of the gyroscope; The detection circuit according to one aspect, wherein the input terminal of the first amplifier is connected to the first output terminal of the vibration sensor, and the input terminal of the second amplifier is connected to the second output terminal of the vibration sensor.

Optionally, the drive circuit is a feedback drive circuit, the input end of the feedback drive circuit is connected to the output end of the second amplifier, and the feedback drive circuit is used to adjust the output value of the second amplifier according to the output value of the second amplifier. The driving voltage is used to keep the vibrating element of the vibration sensor in a stable and constant amplitude vibration state.

In a third aspect, an embodiment of the present invention provides an electronic device, including: a housing; a processor fixed in the housing; a gyroscope fixed in the housing and connected to the processor; the gyroscope It includes: a driving circuit, used to generate a driving voltage; a vibration sensor, the input end of the vibration sensor is connected to the output end of the driving circuit, and is used to vibrate according to the driving voltage, and the first output end of the vibration sensor It is used to output the sensitive mode signal of the gyroscope, and the second output terminal of the vibration sensor is used to output the driving mode signal of the gyroscope; the detection circuit according to the first aspect, wherein the first The input end of the amplifier is connected to the first output end of the vibration sensor, and the input end of the second amplifier is connected to the second output end of the vibration sensor; wherein, the processor is based on the second demodulator The output direct current signal determines the angular velocity of the electronic device.

One or more technical solutions provided in the embodiments of the present invention have at least the following technical effects or advantages:

In the embodiment of the present invention, the signal output by the multiplier is in the same phase as the quadrature error signal. Therefore, by reasonably setting the coefficient signal of the multiplier 103, that is, when the coefficient signal of the multiplier is the first coefficient signal, the subtractor 104 can be made The amplitude of the signal input by the second input end is equivalent to the quadrature error signal, and then the amplitude of the signal with the same phase as the driving mode signal in the signal output by the subtractor 104 is less than or equal to the set threshold, and can even be 0, so as to realize suppression or elimination The quadrature error signal in the sensitive modal signal improves the detection accuracy of the gyroscope. Moreover, in the technical solutions provided by the embodiments of the present invention, no new noise sources are introduced, and the system is simple to implement and low in cost.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings that need to be used in the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For Those of ordinary skill in the art can also obtain other drawings based on these drawings without any creative effort.

Fig. 1 is the schematic diagram of the working principle of the gyroscope in the background technology;

Fig. 2 is the schematic diagram of the gyroscope provided by the embodiment of the present invention;

Fig. 3 is a schematic diagram of a digital-to-analog converter in an embodiment of the present invention.

detailed description

Embodiments of the present invention provide a gyroscope detection circuit, a gyroscope and electronic equipment, which are used to solve the problem that the performance of the gyroscope is restricted by the quadrature error signal in the gyroscope.

The technical solutions of the present invention will be described in detail below through the accompanying drawings and specific examples. It should be understood that the embodiments of the present invention and the specific features in the examples are detailed descriptions of the technical solutions of the present invention, rather than limitations to the technical solutions of the present invention. In the case of no conflict, the embodiments of the present invention and the technical features in the embodiments may be combined with each other.

The gyroscope detection circuit provided by the embodiment of the present invention in the first aspect, referring to FIG. 2 , the detection circuit includes:

The first amplifier 101, the input terminal of the first amplifier 101 is connected to the output terminal of the sensitive mode signal of the gyroscope, and is used for amplifying the sensitive mode signal output by the vibration sensor 114 of the gyroscope.

In actual situations, the capacitance value of the capacitor used to detect sensitive modal vibrations changes when the vibrating part of the gyroscope vibrates in sensitive modals to generate a detection current, which is then converted into a voltage through a resistor, which is the output of the vibration sensor 114 Sensitive modal signals. Due to the influence of factors such as processing accuracy and material residual stress, the output signal of the sensitive mode signal output includes an quadrature error signal, that is, a signal with the same phase as the driving mode signal.

The second amplifier 102, the input terminal of the second amplifier 102 is connected to the output terminal of the driving mode signal of the gyroscope, and is used for amplifying the driving mode signal output by the vibration sensor 114 of the gyroscope.

In actual situations, the capacitance value of the capacitor used to detect the driving mode vibration changes when the vibrating part of the gyroscope undergoes driving mode vibration to generate a driving current, which is then converted into a voltage through a resistor, which is the output of the vibration sensor 114 Drive modal signal.

A multiplier 103, the input terminal of the multiplier 103 is connected to the output terminal of the second amplifier 102, and the multiplier 103 is used to multiply the output signal of the second amplifier 102 by the coefficient signal as the output of the multiplier.

In actual situations, the multiplier can be an α multiplier or a β multiplier, and the multiplier 103 multiplies the signal output by the second amplifier with the coefficient signal, and the phase of the obtained signal is the same as that of the signal output by the second amplifier, namely The phase of the multiplier output signal is the same as that of the drive mode signal.

Subtractor 104, the first input end of subtractor 104 is connected with the output end of first amplifier 101, the second input end of subtractor 104 is connected with the output end of multiplier 103, and the effect of subtractor 104 is: use subtractor 104 The signal at the first input end of the subtractor subtracts the signal at the second input end of the subtractor 104, and the signal after the operation is used as the output of the subtractor 104;

The signal input by the first input terminal of the subtractor 104 includes the sensitive modal signal and the quadrature error signal amplified by the first amplifier, and the signal input by the second input terminal of the subtractor 104 is a signal with the same phase as the driving modal signal, That is, the signal with the same phase as the quadrature error signal, therefore, by reasonably setting the coefficient signal of the multiplier 103, that is, when the coefficient signal of the multiplier is the first coefficient signal, the signal input by the second input terminal of the subtractor 104 can be It is equivalent to the amplitude of the quadrature error signal, and then the amplitude of the signal with the same phase as the driving mode signal in the signal output by the subtractor 104 is less than or equal to the set threshold, and can even be 0, so as to suppress or eliminate the positive signal in the sensitive mode signal. Interchange the error signal to improve the detection accuracy of the gyroscope. Moreover, in the technical solutions provided by the embodiments of the present invention, no new noise sources are introduced, and the system is simple to implement and low in cost.

In actual situations, the threshold is set to a small value, even 0. In addition, the determination of the first coefficient signal can be determined through multiple tests, or can be determined by means of gradual approximation through the error feedback circuit.

Optionally, in the embodiment of the present invention, the detection circuit of the gyroscope also includes:

The first demodulator 105, the input end of the first demodulator 105 is connected with the output end of the subtractor 104, and the first demodulator 105 is used for the input signal of the first demodulator 105 and the driving mode signal phase The same signal is demodulated to a DC signal and a DC signal is output.

In actual situations, after the first demodulation circuit demodulates the signal with the same phase as the driving mode signal into a DC signal, the DC signal can be output through the filter circuit.

Error feedback circuit 106, the input end of the error feedback circuit is connected with the output end of the first demodulator, the output end of the error feedback circuit is connected with the second input end of the multiplier, the error feedback circuit is used for according to the first demodulator The output DC signal adjusts the coefficient signal of the multiplier so that the output DC signal of the first demodulator approaches the set threshold.

Specifically, the function of the error feedback circuit is to dynamically adjust the coefficient signal of the multiplier according to the effect of quadrature error cancellation, so that after the coefficient of the multiplier is adjusted, the DC signal output by the first demodulator is closer to the set threshold until the DC signal Less than or equal to the set threshold to realize the cancellation of the quadrature error signal.

Optionally, the error feedback circuit 106 includes:

Judging unit 107, the input end of the judging unit 107 is connected to the output end of the first demodulator 105, and is used to judge whether the DC signal output by the first demodulator 105 is less than or equal to the set threshold;

Coefficient regulator 108, the input terminal of coefficient regulator 108 is connected with the output terminal of judging unit 107, the output terminal of coefficient regulator 108 is connected with the second input terminal of multiplier 103, the output value of coefficient regulator 108 is used as multiplier coefficient signal;

Wherein, when the DC signal output by the first demodulator is greater than the set threshold, the judging unit instructs the coefficient adjuster to change the output value, so that the DC signal output by the first demodulator becomes smaller after the coefficient adjuster changes the output value .

Specifically, when the judging unit 107 determines that the DC signal output by the first demodulator 105 is greater than the set threshold, it indicates that the quadrature error signal has not been completely canceled, and the coefficient adjuster 108 adjusts the coefficient signal of the multiplier so that the output value of the multiplier is The amplitude is closer to the quadrature error signal, so that the DC signal output by the first demodulator is smaller, and the amplitude of the signal in the output value of the subtractor having the same phase as the driving mode signal is smaller. Through multiple times of feedback by the feedback circuit, the first coefficient signal can be determined, so that the magnitude of the quadrature error signal is less than or equal to the set threshold, and even the quadrature error signal is completely eliminated.

In actual situations, the way for the coefficient adjuster 108 to adjust the coefficient signal of the multiplier 103 includes: first, the coefficient adjuster 108 directly outputs the coefficient signal; second, the coefficient adjuster inputs an adjustment variable to the multiplier, and the multiplier adjusts according to the coefficient The manipulated variable adjustment coefficient signal input by the controller.

Optionally, in this embodiment of the present invention, the coefficient adjuster 108 includes:

Digital signal generator 109, the input end of digital signal generator 109 is connected with the output end of judging unit 107, and digital signal generator 109 is used for generating digital signal according to the instruction of judging unit;

DAC 110, the input end of DAC 110 is connected with the output end of digital signal generator 109, the output end of DAC 110 is connected with the second input end of multiplier, DAC 110 is used for The digital signal output from the digital signal generator 109 is converted into a coefficient signal.

With reference to Fig. 3, it is a kind of realization mode of digital-to-analog converter 110, the digital signal output of digital signal generator is connected to the input conductance of the accumulator shown in Fig. 3, G _c in Fig. 3 is input conductance, G _f Is the feedback resistance, G _i is the input resistance. For other implementation manners of the digital-to-analog converter, please refer to the prior art, and the embodiments of the present invention will not describe in detail.

Optionally, in this embodiment of the present invention, the displacement of the first amplifier 101 is equal to the displacement of the second amplifier 102, so that the signal output by the multiplier 103 can cancel the quadrature error signal in the signal output by the first amplifier 101.

Optionally, in this embodiment of the present invention, the first amplifier 101 and the second amplifier 102 are chopper-stabilized amplifiers.

Optionally, in the embodiment of the present invention, it also includes:

Phase shifter 111, the input end of phase shifter 111 is connected with the output end of the second amplifier 102, and phase shifter 111 is used for the input signal of phase shifter (that is, the driving mode signal after the second amplifier amplifies) The phase is adjusted to the phase of the sensitive mode signal;

The second demodulator 112, the first input end of the second demodulator 112 is connected with the output end of the subtractor 104, the second input end of the second demodulator 112 is connected with the output end of the phase shifter 111, the second The demodulator 112 is configured to demodulate the signal of the same phase as the sensitive mode signal in the input signal of the second demodulator 112 into a DC signal according to the output signal of the phase shifter 111 .

Specifically, the signal output by the subtractor with the same phase as the sensitive mode signal is a modulated signal, which needs to be demodulated according to the driving mode signal. Before demodulation, the phase of the amplified driving mode signal must be adjusted is the phase coincident with the sensitive mode signal.

Since the quadrature error signal contained in the amplified sensitive modal signal is canceled by the subtractor 104, the DC signal output by the second demodulator is more accurate, and when the angular velocity is determined using the DC signal output by the second demodulator, the accuracy Higher, the gyroscope works more stably.

Based on the same technical concept, the embodiment of the present invention provides a gyroscope in the second aspect. Referring to FIG. 2 , the gyroscope includes: a driving circuit 113 , a vibration sensor 114 and the detection circuit provided in the first aspect.

Wherein, the driving circuit 113 is used to generate the driving voltage; the input end of the vibration sensor 114 is connected with the output end of the driving circuit 113, and is used to vibrate according to the driving voltage, and the first output end of the vibration sensor 114 is used to output the sensitive mode of the gyroscope. The second output terminal of the vibration sensor 114 is used to output the driving mode signal of the gyroscope. The input end of the first amplifier in the detection circuit is connected to the first output end of the vibration sensor, and the input end of the second amplifier is connected to the second output end of the vibration sensor.

In actual situations, the vibration sensor includes the vibrating part of the gyroscope, the driving sensing circuit for detecting the driving modal vibration of the vibrating part, and the sensitive sensing circuit for detecting the sensitive modal vibration of the vibrating part, the driving sensing circuit and the sensitive sensing circuit Capacitors and resistors may be included in the circuit, and a voltage signal is output according to the vibration of the vibrating element.

Optionally, in the embodiment of the present invention, the driving circuit 113 is a feedback driving circuit, the input terminal of the feedback driving circuit is connected to the output terminal of the second amplifier 102, and the feedback driving circuit is used to adjust the driving voltage according to the output value of the second amplifier 102 , so that the vibrating part of the oscillating sensor maintains a stable and constant-amplitude oscillating state.

Specifically, the feedback drive circuit may include a demodulator, a comparison circuit, and a variable gain amplifier. The specific implementation method refers to the prior art, and the closed-loop drive loop is realized through the feedback drive circuit to ensure that the vibrating part of the gyroscope maintains a stable constant amplitude. The vibration state ensures the accuracy and stable operation of the gyroscope.

Based on the same technical concept, an embodiment of the present invention provides an electronic device in a third aspect, and the electronic device includes: a casing, the gyroscope provided in the second aspect, and a processor. Wherein, the gyroscope and the processor are fixed in the housing and electrically connected, and the processor is used to determine the angular velocity of the electronic device according to the DC signal output by the second demodulator 112 .

During specific implementation, the processor and the gyroscope may be integrated together, or they may be two different chips, which are not limited in this embodiment of the present invention.

In addition, in the embodiment of the present invention, the first demodulator 105 and the error feedback circuit 106 can be integrated with other parts of the detection circuit of the gyroscope, that is, realized on-chip. In practice, the first demodulator 105 and the error feedback circuit 106 can also be implemented off-chip to reduce the overhead of the internal circuit and save the area and power consumption of the gyroscope detection circuit.

One or more technical solutions provided in the embodiments of the present invention have at least the following technical effects or advantages:

In the embodiment of the present invention, the signal output by the multiplier is in the same phase as the quadrature error signal. Therefore, by reasonably setting the coefficient signal of the multiplier 103, that is, when the coefficient signal of the multiplier is the first coefficient signal, the subtractor 104 can be made The amplitude of the signal input by the second input end is equivalent to the quadrature error signal, and then the amplitude of the signal with the same phase as the driving mode signal in the signal output by the subtractor 104 is less than or equal to the set threshold, and can even be 0, so as to realize suppression or elimination The quadrature error signal in the sensitive modal signal improves the detection accuracy of the gyroscope. Moreover, in the technical solutions provided by the embodiments of the present invention, no new noise sources are introduced, and the system is simple to implement and low in cost.

Those skilled in the art should understand that the embodiments of the present invention may be provided as methods, systems, or computer program products. Accordingly, the present invention can take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention may take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) having computer-usable program code embodied therein.

The present invention is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It should be understood that each procedure and/or block in the flowchart and/or block diagram, and a combination of procedures and/or blocks in the flowchart and/or block diagram can be realized by computer program instructions. These computer program instructions may be provided to a general purpose computer, special purpose computer, embedded processor, or processor of other programmable data processing equipment to produce a machine such that the instructions executed by the processor of the computer or other programmable data processing equipment produce a An apparatus for realizing the functions specified in one or more procedures of the flowchart and/or one or more blocks of the block diagram.

These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing apparatus to operate in a specific manner, such that the instructions stored in the computer-readable memory produce an article of manufacture comprising instruction means, the instructions The device realizes the function specified in one or more procedures of the flowchart and/or one or more blocks of the block diagram.

While preferred embodiments of the invention have been described, additional changes and modifications to these embodiments can be made by those skilled in the art once the basic inventive concept is appreciated. Therefore, it is intended that the appended claims be construed to cover the preferred embodiment as well as all changes and modifications which fall within the scope of the invention.

Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and equivalent technologies thereof, the present invention also intends to include these modifications and variations.

Claims (10)

1. a gyroscope testing circuit, it is characterised in that including:

First amplifier, the sense mode signal output part phase of the input of described first amplifier and gyroscope Even；

Second amplifier, the input of described second amplifier exports with the driven-mode signal of described gyroscope End is connected；

Multiplier, the input of described multiplier is connected with the outfan of described second amplifier, described multiplication Device is for being multiplied by the coefficient signal output as described multiplier, institute using the output signal of described second amplifier The phase place stating multiplier output signal is identical with the phase place of described driven-mode signal；

Subtractor, the first input end of described subtractor is connected with the outfan of described first amplifier, described Second input of subtractor is connected with the outfan of described multiplier, and described subtractor is for by described first The signal of input deducts the signal output as described subtractor of described second input；

Wherein, when the coefficient signal of described multiplier is the first coefficient signal, the letter of described subtractor output The amplitude of signal identical with described driven-mode signal phase in number is less than or equal to setting threshold value.

2. circuit as claimed in claim 1, it is characterised in that also include:

First demodulator, the input of described first demodulator is connected with the outfan of described subtractor, described First demodulator for by the input signal of described first demodulator with described driven-mode signal phase phase Same signal is demodulated into direct current signal, and exports described direct current signal；

Error feedback circuit, the outfan phase of the input of described error feedback circuit and described first demodulator Even, the outfan of described error feedback circuit is connected with the second input of described multiplier, and described error is anti- Current feed circuit for what the described direct current signal according to the output of described first demodulator adjusted described multiplier is Number signal, so that the described direct current signal of the output of described first demodulator approaches described setting threshold value.

3. circuit as claimed in claim 2, it is characterised in that described error feedback circuit includes:

Judging unit, the input of described judging unit is connected with the outfan of described first demodulator, is used for Judge that whether the described direct current signal of output of described first demodulator is less than or equal to described setting threshold value；

Coefficient adjuster, the input of described coefficient adjuster is connected with the outfan of described judging unit, institute Second input of the outfan and described multiplier of stating coefficient adjuster is connected, described coefficient adjuster defeated Go out the value coefficient signal as described multiplier；

Wherein, described judging unit be more than at the described direct current signal of the output of described first demodulator described in set When determining threshold value, described coefficient adjuster is indicated to change output valve, so that described first demodulator output is described Direct current signal diminishes after described coefficient adjuster changes output valve.

4. circuit as claimed in claim 3, it is characterised in that described coefficient adjuster includes:

The outfan of digital signal generator, the input of described digital signal generator and described judging unit Being connected, described digital signal generator generates digital signal for the instruction according to described judging unit；

Digital to analog converter, the outfan phase of the input of described digital to analog converter and described digital signal generator Even, the outfan of described digital to analog converter is connected with the second input of described multiplier, described digital-to-analogue conversion Device is for being converted to described coefficient signal by the digital signal that described digital signal generator exports.

5. circuit as claimed in claim 1, it is characterised in that the displacement of described first amplifier is equal to The displacement of described second amplifier.

6. circuit as claimed in claim 1, it is characterised in that described first amplifier, described second Amplifier is chopper stabilized amplifier.

7. the circuit as according to any one of claim 1-6, it is characterised in that also include:

Phase shifter, the input of described phase shifter is connected with the outfan of described second amplifier, described phase shift Device for being adjusted to the phase place of described sense mode signal by the phase place of input signal；

Second demodulator, the first input end of described second demodulator is connected with the outfan of described subtractor, Second input of described second demodulator is connected with the outfan of described phase shifter, and described second demodulator is used In the output signal according to the described phase shifter, by the input signal of described second demodulator with described sensitive mould The signal that state signal phase is identical is demodulated into direct current signal.

8. a gyroscope, it is characterised in that including:

Drive circuit, is used for producing driving voltage；

Vibrating sensor, the input of described vibrating sensor is connected with the outfan of described drive circuit, uses In vibrating according to described driving voltage, the first outfan of described vibrating sensor is used for exporting described top The sense mode signal of spiral shell instrument, the second outfan of described vibrating sensor is for exporting driving of described gyroscope Dynamic mode signals；

Testing circuit as according to any one of claim 1-7, wherein, the input of described first amplifier End is connected with the first outfan of described vibrating sensor, the input of described second amplifier and described vibration Second outfan of sensor is connected.

9. gyroscope as claimed in claim 8, it is characterised in that described drive circuit drives for feedback Circuit, the input of described feedback driving circuit is connected with the outfan of described second amplifier, described feedback Drive circuit adjusts described driving voltage for the output valve according to described second amplifier, so that described vibration The vibrating member of sensor keeps stable permanent width concussion state.

10. an electronic equipment, it is characterised in that including:

Housing；

Processor, is fixed in described housing；

Gyroscope, is fixed in described housing, is connected with described processor；Described gyroscope includes:

Drive circuit, is used for producing driving voltage；

Vibrating sensor, the input of described vibrating sensor is connected with the outfan of described drive circuit, uses In vibrating according to described driving voltage, the first outfan of described vibrating sensor is used for exporting described top The sense mode signal of spiral shell instrument, the second outfan of described vibrating sensor is for exporting driving of described gyroscope Dynamic mode signals；

Testing circuit as claimed in claim 7, wherein, the input of described first amplifier shakes with described First outfan of dynamic sensor is connected, the of the input of described second amplifier and described vibrating sensor Two outfans are connected；

Wherein, described processor determines described electronics according to the described direct current signal of described second demodulator output The angular velocity of equipment.