CN100585331C - Double quality oscillatory type silicon micro-gyroscopes - Google Patents
Double quality oscillatory type silicon micro-gyroscopes Download PDFInfo
- Publication number
- CN100585331C CN100585331C CN200710133223A CN200710133223A CN100585331C CN 100585331 C CN100585331 C CN 100585331C CN 200710133223 A CN200710133223 A CN 200710133223A CN 200710133223 A CN200710133223 A CN 200710133223A CN 100585331 C CN100585331 C CN 100585331C
- Authority
- CN
- China
- Prior art keywords
- broach
- resonator
- type silicon
- oscillatory type
- silicon micro
- 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
Images
Landscapes
- Gyroscopes (AREA)
Abstract
The invention comprises an upper layer and a lower layer. On the upper layer there is a gyroscope mechanical structure made on a monocrystalline silicon plate; on the lower layer there are signal leads made on the glass substrate. The gyroscope mechanical structure is composed of two identical substructures; said two substructures are set in bilateral symmetry and respectively connected to the cross beam; the cross beam is connected to the fixed base through two groups of twisted bars; said fixed base is mounted on the linkage point o the fixed base on the glass substrate in order to make the mechanical structure part on the upper layer hang above the glass substrate.
Description
Technical field
The invention belongs to microelectromechanical systems and micro-inertia measuring technology, particularly a kind of double quality oscillatory type silicon micro-gyroscopes.
Background technology
The micro-mechanical inertia instrument comprises micro-mechanical gyroscope (MMG) and micro-mechanical accelerometer (MMA).Utilize microelectronic processing technology to allow micro mechanical structure and required electronic circuit are completely integrated on the silicon chip, thereby reach the high unity of performance, price, volume, weight, reliability aspects.Thereby this class instrument has a series of advantage (little, in light weight as volume, low price, reliability height, can produce in enormous quantities etc.), all is being with a wide range of applications aspect the army and the people two.Aspect civilian, be mainly used in auto industry, industrial monitoring and consumer product and Robotics, as air bag, anti-lock braking system, yaw rate sensor, tumble rate sensor, image stability and toy or the like; In military domain, be mainly used in the independent navigation guidance system of agile bomb, intelligent projectile, tactical missile, new concept weapon and miniplane etc.
1993, a kind of micromechanical gyro of novelty-tuning-fork type line oscillation gyro (M.Weinberg has been passed through in the topped silicon layer fabrication techniques of glass surface in U.S. De Leipo laboratory, J.Bernstein, et al.Amicromachined comb-drivetuning fork rate gyroscope.Proc.Of the 49
ThAnnual meeting " Future global navigation andguidance ", the Institute of Navigation, June 21-23,1993, pp.595-601).This gyroscope is made up of double quality blocks, support beam and crossbeam, and gyroscope adopts the line vibratory drive, and angular oscillation is responsive to be detected, and can detect the axial input angle speed on gyroscope plane.This gyrostatic double quality blocks design can increase output signal, but its driving and responsive motion coupling fully, and the linearity of angular oscillation is relatively poor, has limited the raising of its sensitivity.
Summary of the invention
The object of the present invention is to provide a kind of can the realization to drive mode and the mobile decoupling, violent oscillatory motion, the detection output decoupling that detect mode, reach the double quality oscillatory type silicon micro-gyroscopes that error is little, antijamming capability is strong, highly sensitive.
The technical solution that realizes the object of the invention is: a kind of double quality oscillatory type silicon micro-gyroscopes, by last, following two-layer formation, the upper strata is the gyroscope physical construction that is produced on the monocrystalline silicon piece, lower floor is the signal lead that is produced on the glass substrate, gyroscope upper strata physical construction is made up of a pair of identical minor structure, these two minor structures are symmetrical set, and be connected with crossbeam respectively, this crossbeam is connected with fixed pedestal by two groups of torsion bars, this fixed pedestal is installed on the retainingf key chalaza on the glass substrate, makes the physical construction part on upper strata unsettled on the glass substrate part of lower floor; Each minor structure is made up of mass, resonator, driving support beam, detection support beam and fixing responsive broach, the detection support beam that each mass passes through separately respectively links to each other with transverse slat, and the resonator separately on this transverse slat links to each other with crossbeam by driving support beam; Drive support beam and with the detection support beam drive part and test section are separated, drive part is made up of resonator, transverse slat, and detection architecture is made up of the movable responsive broach on fixing responsive broach and mass and the mass.
The present invention compared with prior art, its remarkable advantage is: (1) two minor structure is symmetrically arranged, and has increased output signal, is the twice of single mass output signal; (2) adopt two groups of support beams that drive part and test section are separated, realized driving direction and detection side to mobile decoupling, thereby reduce error signal; The actuation movement of (3) two minor structures and detection motion are move toward one another, form the broach differential capacitor and detect, and have realized responsive output decoupling, have suppressed undesired signal; (4) torsion bar symmetric arrangement has in twos increased y, the rotational stiffness of z axle and the bending stiffness of z axle, has increased impact resistance, in addition, has also increased the dirigibility of regulating mode of oscillation and resonance frequency; (5) detect the structure that support beam adopts U type beam, heat release stress effectively not only, and suppressed quadrature coupling error signal, and in addition, also reduced the non-linear of motion, thereby can increase Oscillation Amplitude, improve detection sensitivity; The resonator broach antisymmetry of (6) two minor structures is arranged, applies identical driving voltage on the driving comb of two minor structures, just can make two minor structure move toward one another, thereby has simplified circuit.Design in this invention does not also have relevant, similar design at home.
Below in conjunction with accompanying drawing the present invention is described in further detail.
Description of drawings
Fig. 1 is the structural representation of double quality oscillatory type silicon micro-gyroscopes of the present invention.
Fig. 2 is the resonator structure synoptic diagram of double quality oscillatory type silicon micro-gyroscopes of the present invention.
Fig. 3 is the detection architecture synoptic diagram of double quality oscillatory type silicon micro-gyroscopes of the present invention.
Fig. 4 is the signal lead synoptic diagram on the glass substrate of double quality oscillatory type silicon micro-gyroscopes of the present invention lower floor.
Embodiment
In conjunction with Fig. 1, double quality oscillatory type silicon micro-gyroscopes of the present invention, be used for the surveying instrument of measuring vertical in base level, by last, following two-layer formation, the upper strata is the gyroscope physical construction that is produced on the monocrystalline silicon piece, lower floor is the signal lead that is produced on the glass substrate, gyroscope upper strata physical construction is by a pair of identical minor structure 100,200 form, these two minor structures 100,200 are symmetrical set, and respectively with crossbeam 3a, 3b connects, this crossbeam 3a, 3b is by two groups of torsion bar 2a, 2b, 2c, 2d and fixed pedestal 1a, 1b connects, this gyrostatic resonator 120a structure as shown in Figure 2, resonator 210a is made up of three groups of linear pectination broach electric capacity.Wherein, middle one group is the drive feedback broach, is made up of the movable broach on fixed drive feedback broach 104a and the transverse slat 107a.Two groups is driving comb in addition, is made up of the movable broach on fixed drive broach 103a, 103b and the transverse slat 107a.The responsive broach of mass 101,201 symmetria bilateralis distribution linears, responsive broach is become insert group with movable responsive broach on the mass 101,201 by fixing responsive broach 102a, 102b, 202a, 202b, as shown in Figure 3.Whole gyrostatic superstructure is by two groups of torsion bar 2a, 2b, 2c, 2d and fixed pedestal 1a, 1b are unsettled is installed on the glass substrate.Wherein, every group of torsion bar is by torsion bar 2a, 2b, 2c, 2d symmetric arrangement.Detect the structure of support beam 106a, 106b, 106c, 106d, 206a, 206b, 206c, 206d employing U type beam.On fixed drive broach 103a, 103b, 103c, 103d, 203a, 203b, 203c, 203d, apply the alternating voltage of band direct current biasing, adopt monolateral static driven, the working method that differential capacitor detects.Fixed pedestal 1a, 1b link to each other with retainingf key chalaza 4a, 4b, and fixed drive broach 103a, 103b, 103c, 103d, 203a, 203b, 203c, 203d, fixed drive feedback broach 104a, 104b, 204a, 204b, fixing responsive broach 102a, 102b, 202a, 202b link to each other with corresponding keys chalaza 112a, 112b, 112c, 112d, 212a, 212b, 212c, 212d, 113a, 113b, 213a, 213b, 111a, 111b, 211a, the 211b of lower floor glass substrate respectively.
Each above-mentioned minor structure is by mass 101,201, resonator 120a, 120b, 220a, 220b, drive support beam 105a, 105b, 105c, 105d, 205a, 205b, 205c, 205d, detect support beam 106a, 106b, 106c, 106d, 206a, 206b, 206c, 206d and fixing responsive broach 102a, 102b, 202a, 202b forms, each mass 101,201 pass through detection support beam 106a separately respectively, 106b, 106c, 106d, 206a, 206b, 206c, 206d and transverse slat 107a, 107b, 207a, 207b links to each other, this transverse slat 107a, 107b, 207a, the 120a of resonator separately on the 207b, 120b, 220a, 220b is by driving support beam 105a, 105b, 105c, 105d, 205a, 205b, 205c, 205d and crossbeam 3a, 3b links to each other.Wherein, driving support beam 105a, 105b, 105c, 105d, 205a, 205b, 205c, 205d and detection support beam 106a, 106b, 106c, 106d, 206a, 206b, 206c, 206d separate drive part and test section, drive part is made up of resonator 120a, 120b, 220a, 220b, transverse slat 107a, 107b, 207a, 207b, and detection architecture is made up of the movable responsive broach on fixing responsive broach 102a, 102b, 202a, 202b and mass 101,201 and the mass 101,201.Resonator 120a, the 120b of minor structure 100,200, the broach of 220a, 220b are arranged as antisymmetry and arrange.Resonator 120a, 120b, 220a, 220b are limited in the directions X motion.Movable responsive broach on fixing responsive broach 102a, 102b, 202a, 202b and the mass 101,201 constitutes the broach differential capacitor.
Glass substrate comprises signal lead and metal silicon/glass bonding point as shown in Figure 4.Signal lead comprises ground wire 5, drives input lead 109a, 109b, 209a, 209b, drive feedback input lead 110,210, responsive output signal lead-in wire 108,208; Metal silicon/glass bonding point comprises retainingf key chalaza 4a, 4b, fixed drive broach bonding point 112a, 112b, 112c, 112d and 212a, 212b, 212c, 212d, fixed drive feedback broach bonding point 113a, 113b and 213a, 213b, fixing responsive broach bonding point 111a, 111b and 211a, 211b.
Double quality oscillatory type silicon micro-gyroscopes of the present invention adopts monolateral static driven, the working method of capacitance detecting.Apply the alternating voltage that contains dc offset voltage on the fixed drive broach 103a of pectination resonator 120a, the 120b of structure 100,103b, 103c, 103d, produce the electrostatic force of alternation, static driven power is:
In the formula, n is the movable broach number of resonator, and ε is a specific inductive capacity, and h is a thickness of structure, and d is the broach spacing, U
dBe the dc offset voltage of driving voltage, U
aBe alternating voltage, ω
dAngular frequency for alternating voltage.
In like manner, on fixed fingers 203a, the 203b of pectination resonator 220a, the 220b of structure 200,203c, 203d, apply the identical alternating voltage of phase place that contains dc offset voltage, produce the electrostatic force of alternation, because the broach of minor structure 100 and 200 resonators is arranged as antisymmetry and arranges, therefore, it is opposite to act on the static driven force direction of structure 100 and 200.
So the whole bascule of structure 100 and 200 is done simple harmonic quantity line vibration in opposite directions along driving shaft under the effect of static driven power.When the natural frequency of the frequency that drives alternating voltage and gyroscope driving mode was consistent, the line vibration displacement was:
In the formula, F
D0Be static driven power amplitude, k
xBe the elastic stiffness of directions X, Q
xFor driving the quality factor of mode.
The line vibration velocity is:
When gyroscope has extraneous input angle speed ω around the z axle
zThe time, according to the right-hand rule, detecting quality and be subjected to the effect of Corioli's acceleration at output shaft (Y-axis), its size is:
In the formula,
Be dextrorotation angle between input angle speed and the line vibration velocity.
If the detection quality is m
s, then act on and detect qualitatively that De Geshi inertial force is:
The direction of Ge Shi inertial force is opposite with the Corioli's acceleration direction, and therefore, the direction that acts on De Geshi inertial force on the mass 101,201 is opposite.Under the effect of Ge Shi inertial force, mass 101,201 is done simple harmonic quantity line vibration in opposite directions along sensitive axes (Y-axis).Like this, make that the gap between movable responsive broach and the fixing responsive broach changes by certain simple harmonic oscillation rule, the capacitance difference value signal can obtain output voltage signal after electronic circuit is handled.Output voltage signal is minor structure 100,200 output voltage signal sums, and the size of output voltage signal is proportional to the size of input angle speed.By the phase relation of phase detector comparison output voltage signal and pumping signal, then can distinguish the direction of input angle speed.
Claims (8)
1, a kind of double quality oscillatory type silicon micro-gyroscopes, by last, following two-layer formation, the upper strata is the gyroscope physical construction that is produced on the monocrystalline silicon piece, lower floor is the signal lead that is produced on the glass substrate, it is characterized in that: gyroscope upper strata physical construction is by a pair of identical minor structure [100,200] form, these two minor structures [100,200] be symmetrical set, and respectively with crossbeam [3a, 3b] connect, this crossbeam [3a, 3b] by two groups of torsion bar [2a, 2b, 2c, 2d] and fixed pedestal [1a, 1b] connect, this fixed pedestal [1a, 1b] be installed in the retainingf key chalaza [4a on the glass substrate, 4b] on, make the physical construction part on upper strata unsettled on the glass substrate part of lower floor; Each minor structure is by mass [101,201], resonator [120a, 120b, 220a, 220b], drive support beam [105a, 105b, 105c, 105d, 205a, 205b, 205c, 205d], detect support beam [106a, 106b, 106c, 106d, 206a, 206b, 206c, 206d] and fixing responsive broach [102a, 102b, 202a, 202b] form, each mass [101,201] the detection support beam [106a by separately respectively, 106b, 106c, 106d, 206a, 206b, 206c, 206d] and transverse slat [107a, 107b, 207a, 207b] link to each other this transverse slat [107a, 107b, 207a, 207b] on [the 120a of resonator separately, 120b, 220a, 220b] by driving support beam [105a, 105b, 105c, 105d, 205a, 205b, 205c, 205d] and crossbeam [3a, 3b] link to each other; Driving support beam [105a, 105b, 105c, 105d, 205a, 205b, 205c, 205d] and detection support beam [106a, 106b, 106c, 106d, 206a, 206b, 206c, 206d] separates drive part and test section, drive part is made up of resonator [120a, 120b, 220a, 220b], transverse slat [107a, 107b, 207a, 207b], and detection architecture is made up of the movable responsive broach on fixing responsive broach [102a, 102b, 202a, 202b] and mass [101,201] and the mass [101,201].
2, double quality oscillatory type silicon micro-gyroscopes according to claim 1 is characterized in that: the broach of the resonator [120a, 120b, 220a, 220b] of minor structure [100,200] is arranged as antisymmetry and arranges.
3, double quality oscillatory type silicon micro-gyroscopes according to claim 1 is characterized in that: resonator [120a, 120b, 220a, 220b] is limited in the directions X motion.
4, double quality oscillatory type silicon micro-gyroscopes according to claim 1, it is characterized in that: the responsive broach of mass [101,201] symmetria bilateralis distribution linear, responsive broach is made up of the movable responsive broach interdigitation on fixing responsive broach and the mass [101,201], and fixing responsive broach [102a, 102b, 202a, 202b] constitutes the broach differential capacitor with movable responsive broach.
5, double quality oscillatory type silicon micro-gyroscopes according to claim 1 is characterized in that: every group of torsion bar is respectively by two torsion bars [2a, 2b, 2c, 2d] symmetric arrangement.
6, double quality oscillatory type silicon micro-gyroscopes according to claim 1 is characterized in that: detect the structure that support beam [106a, 106b, 106c, 106d, 206a, 206b, 206c, 206d] adopts U type beam.
7, double quality oscillatory type silicon micro-gyroscopes according to claim 1, it is characterized in that: the alternating voltage that on the fixed drive broach [103a, 103b, 103c, 103d, 203a, 203b, 203c, 203d] of resonator [120a, 120b, 220a, 220b], applies the band direct current biasing, adopt monolateral static driven, the working method that differential capacitor detects.
8, double quality oscillatory type silicon micro-gyroscopes according to claim 1, it is characterized in that: fixed pedestal [1a, 1b] and retainingf key chalaza [4a, 4b] link to each other resonator [120a, 120b, 220a, 220b] fixed drive broach [103a, 103b, 103c, 103d, 203a, 203b, 203c, 203d], resonator [120a, 120b, 220a, 220b] fixed drive feedback broach [104a, 104b, 204a, 204b], fixing responsive broach [102a, 102b, 202a, 202b] respectively with the corresponding keys chalaza [112a of lower floor's glass substrate, 112b, 112c, 112d, 212a, 212b, 212c, 212d, 113a, 113b, 213a, 213b, 111a, 111b, 211a, 211b] link to each other.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN200710133223A CN100585331C (en) | 2007-10-12 | 2007-10-12 | Double quality oscillatory type silicon micro-gyroscopes |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN200710133223A CN100585331C (en) | 2007-10-12 | 2007-10-12 | Double quality oscillatory type silicon micro-gyroscopes |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN101135559A CN101135559A (en) | 2008-03-05 |
| CN100585331C true CN100585331C (en) | 2010-01-27 |
Family
ID=39159775
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN200710133223A Active CN100585331C (en) | 2007-10-12 | 2007-10-12 | Double quality oscillatory type silicon micro-gyroscopes |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN100585331C (en) |
Families Citing this family (17)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP2417053B1 (en) * | 2009-04-07 | 2015-05-27 | Siemens Aktiengesellschaft | Micromechanical system having seismic mass |
| CN102798386A (en) * | 2011-05-25 | 2012-11-28 | 上海飞恩微电子有限公司 | Three-degree-of-freedom resonance silicon micromechanical gyroscope |
| CN102252668B (en) * | 2011-06-23 | 2014-01-01 | 南京理工大学 | Silicon micro angular vibration output gyroscope |
| CN102706338A (en) * | 2012-06-19 | 2012-10-03 | 清华大学 | Giant magnetoresistive effect-based micro mechanical gyro |
| CN104215236B (en) | 2013-06-05 | 2016-12-28 | 中国科学院地质与地球物理研究所 | A kind of anti-phase vibratory gyroscope of MEMS and manufacturing process thereof |
| JP6481294B2 (en) * | 2014-09-05 | 2019-03-13 | セイコーエプソン株式会社 | Physical quantity sensor element, physical quantity sensor, electronic device and mobile object |
| CN104459181B (en) * | 2014-12-31 | 2017-06-23 | 东南大学 | A kind of bionical hair sensor sensitive for flow velocity, acceleration and angular speed |
| CN105466406B (en) * | 2015-12-28 | 2019-01-18 | 南京理工大学 | The Technology of Silicon Micromechanical Vibrating Gyroscope of I-shaped structure |
| CN105953781A (en) * | 2016-06-03 | 2016-09-21 | 哈尔滨工业大学 | Tuning-fork micromechanical gyroscope sensor applied to wireless sensor network |
| CN107782294B (en) * | 2016-08-24 | 2021-01-26 | 南京理工大学 | Double-mass-block tuning fork gyroscope with stress isolation capability |
| CN106813654B (en) * | 2016-10-08 | 2023-11-03 | 南京理工大学 | Double-mass tuning fork angular rate gyroscope with structural decoupling capability |
| CN106500732A (en) * | 2016-12-22 | 2017-03-15 | 四川纳杰微电子技术有限公司 | A kind of micro-mechanical gyroscope quadrature error collocation structure |
| CN107063222B (en) * | 2017-04-17 | 2019-07-12 | 东南大学 | The double quality silicon micromechanical gyroscopes of three frame-types of direct rate-adaptive pacemaker |
| CN108731659A (en) * | 2018-05-25 | 2018-11-02 | 中国电子科技集团公司第二十九研究所 | A kind of more detection vibration unit micro-inertial navigation gyroscopes |
| CN111650401B (en) * | 2020-06-03 | 2021-05-07 | 西安交通大学 | Coplanar-mounted metal-based integrated resonant accelerometer |
| CN111551161A (en) * | 2020-06-28 | 2020-08-18 | 江苏睦荷科技有限公司 | MEMS vibrating gyroscope structure and manufacturing method thereof |
| CN112833869B (en) * | 2021-01-06 | 2022-04-19 | 南京理工大学 | Decoupling type double-mass silicon micromechanical vibration gyroscope structure |
-
2007
- 2007-10-12 CN CN200710133223A patent/CN100585331C/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN101135559A (en) | 2008-03-05 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN100585331C (en) | Double quality oscillatory type silicon micro-gyroscopes | |
| CN106813654B (en) | Double-mass tuning fork angular rate gyroscope with structural decoupling capability | |
| US8342023B2 (en) | Coriolis gyro | |
| CN102252668B (en) | Silicon micro angular vibration output gyroscope | |
| CN102066874B (en) | Vibrating micro-mechanical sensor of angular velocity | |
| EP2404139B1 (en) | Vibrating micro-mechanical sensor of angular velocity | |
| US11015933B2 (en) | Micromechanical detection structure for a MEMS sensor device, in particular a MEMS gyroscope, with improved driving features | |
| CN101876547B (en) | Horizontal shaft micro-mechanical tuning fork gyroscope adopting electrostatic balance comb tooth driver | |
| CN102062604A (en) | Capacitive micromachined tuning fork gyroscope | |
| US8656778B2 (en) | In-plane capacitive mems accelerometer | |
| CN102798386A (en) | Three-degree-of-freedom resonance silicon micromechanical gyroscope | |
| CN102495236A (en) | High-sensitivity dual-axis silicon-micro resonance accelerometer | |
| CN101509771A (en) | Decoupling micromechanical gyroscope | |
| WO2017007428A1 (en) | Motion measurement devices and methods for measuring motion | |
| CN105466406A (en) | Silicon micromechanical vibrating gyroscope of I-shaped structure | |
| CN102221361B (en) | Capacitive micro machinery gyroscope | |
| CN206177311U (en) | Two quality piece sound fork angle rate gyroscope with structure decoupling zero ability | |
| CN109556589B (en) | High overload resistant double-mass-block tuning fork type angular rate gyroscope | |
| CN107782294B (en) | Double-mass-block tuning fork gyroscope with stress isolation capability | |
| CN202216695U (en) | Silicon micro angle vibration output gyro | |
| Kuisma et al. | A bulk micromachined silicon angular rate sensor | |
| CN101498580B (en) | Oscillation type silicon micro-gyroscope | |
| CN101746708B (en) | Fully-decoupled capacitance type micromachined gyroscope | |
| CN107687845B (en) | Rotary output tuning fork angular rate gyroscope with double mass blocks | |
| CN101135560A (en) | Crewel vibrating silicon micro-gyroscopes |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C53 | Correction of patent for invention or patent application | ||
| CB03 | Change of inventor or designer information |
Inventor after: Qiu Anping Inventor after: Shi Qin Inventor after: Su Yan Inventor after: Zhu Xinhua Inventor after: Ding Henggao Inventor before: Qiu Anping Inventor before: Shi Qin Inventor before: Su Yan Inventor before: Zhu Xinhua |
|
| COR | Change of bibliographic data |
Free format text: CORRECT: INVENTOR; FROM: QIU ANPING SHI QIN SU YAN ZHU XINHUA TO: QIU ANPING SHI QIN SU YAN ZHU XINHUA DING HENGGAO |