CN2474994Y - Micro pilot apparatus based on micro computer electric technology - Google Patents

Abstract

The utility model belongs to the technical field of minitype measurement units, which comprises a plurality of sensors, an A/D converter, a microprocessor, a PC machine, and an RS232 standard serial port, which is characterized in that the sensor comprises a triaxial silicon accelerometer and a surrounding circuit, a three-shaft gaussmeter and a surrounding circuit, and signal processing and display software modules which are pre-stored in the microprocessor and the PC machine. The utility model can achieve the whole gesture information of a moving carrier with whole solid structure, small cubage, lightness, low power consumption, fast start-up, and low cost and the like.

Description

Miniature guider based on micro-electromechanical technology

The utility model belongs to miniature surveying instrument technical field, the particularly design of miniature guider.

Navigation is to utilize various sensors to carry out Measurement and analysis to obtain position and the attitude of carrier with respect to reference data.Traditional guider has: (1) inertial navigation unit, it is made up of gyroscope and accelerometer.Wherein gyroscope costs an arm and a leg, volume is big, it is long to ask when starting, it is high that environmental baseline is required; (2) visual guider is debated links such as knowledge and is formed by shooting, image processing, image, and in the implementation process of this navigation, may occur taking blind spot and cause misleading, in addition, and the image processing procedure complexity, real-time is poor; (3) global location device (GPS), it is made up of 24 satellites, geoceiver and processors, because it has the error of artificial adding in time and satellite position information, thereby has limited the measuring accuracy of GPS navigation device.In addition because GPS needs the external world that reference information is provided, be not suitable for adopting this kind mode so carrier under water navigated.Comparatively speaking, emerging micro electronmechanical guider based on silicon micro-sensor, but can the implement device microminiaturization, practicability and intelligentized perfect adaptation, all has the absolute predominance that surmounts traditional guider on the price, on the size, on the weight and on the performance, not only can be for large-scale motion carriers such as boats and ships, aircraft navigate, and be applicable to the attitude measurement and the control of small-sized carrier (as: robot, unmanned flivver, guided missile etc.) more.

Microelectromechanicdevices devices (MEMS) is with microelectric technique and micro mechanical technology combination, sensor and its treatment circuit is completely integrated on the silicon microstructure sensor chip, thus the micro device of realization electromechanical integration.

Sensor in the microelectromechanicdevices devices is to use the silicon microstructure sensor that micromachining technologies such as photoetching, burn into deposition, ion injection, bonding are produced on electrooptical material chips such as monocrystalline silicon, quartz crystal, lithium niobate, and it has, and cost is low, volume is little, light weight, power consumption is little, reliability is high, be easy to realize advantages such as digitizing and intellectuality.Main representative based on the miniature guider of micro-electromechanical technology will belong to the digital magnetic resistance compass HMR3000 of the end of the nineties by the development and production of U.S. Honeywell company, its major function provides course information, negative effect for compensating for tilt, also set up inclination sensor in the device, to eliminate the influence of the course being measured less than 40 ° of inclinations.Its composition and principle of work be as shown in Figure 1: record small size pitch angle by the diaxon inclinator that is filled with liquid, pitch angle information is calculated in single-chip microcomputer with three road field signals that recorded by three magnetoresistive transducers, calculate course data, angle-data carries out communication by RS232 standard serial mouth and PC.Magnetoresistive transducer wherein is to be made by permalloy thin slice (NiFe), adopts very little solid-state encapsulation.HMR3000 can measure 0 °～360 ° course less than 40 ° of inclinations, the course measuring accuracy be ± 1.0 ° (horizontal levels) and ± 2.0 (obliquities); The inclination measurement scope is ± 40 °, the inclination measurement precision be ± 0.4 ° (when＜20 °) and ± 0.6 ° (when＞20 °).

There are the following problems for this HMR3000 numeral magnetic resistance compass:

(1) the angle of bank measurement scope is little, can only measure the pitch angle less than 40 °;

(2) measuring accuracy can reduce along with the increase at angle of inclination, is ± 1.0 ° as the course precision when the horizontal level, and when run-off the straight, the course precision reduces to ± and 2.0 °; For tilt accuracy, along with the increase at angle of inclination, tilt accuracy by ± 0.4 ° reduce to ± 0.6 °.

The purpose of this utility model is for overcoming the weak point of prior art, design a kind of novel miniature guider based on micro-electromechanical technology, on the basis of above-mentioned digital magnetic resistance compass, its structure composition and software algorithm have all been done bigger change, collecting multiple MEMS sensor is one, by processing to acquired signal, can access the full attitude information of motion carrier, have characteristics such as structure of whole solid state, volume are little, in light weight, low-power consumption, startup is fast, cost is low.

The utility model is designed a kind of novel miniature guider based on micro-electromechanical technology, comprise a plurality of sensors, the A/D converter that the signal that this sensor is recorded is changed, the microprocessor that the digital signal of this A/D converter output is calculated, the RS232 standard serial mouth that microprocessor is linked to each other with PC, it is characterized in that, said sensor is made up of three silicon micro accerometers and peripheral circuit thereof and three axis magnetometer and peripheral circuit thereof, and is stored in signal Processing and software for display module in said microprocessor and the PC in advance.

Said signal Processing and software for display module comprise that sensor signal Fusion Module, attitude algorithm module, graphic interface module, user operate the demonstration interface module.

Signal fused module of the present utility model comprises: signal filtering and conversion of signals two parts.Wherein:

Finite impulse response (FIR) digital filtering is adopted in signal filtering, and promptly the output y (n) of digital filtering depends on the input in past limited and present input x (n), x (n-1) ..., x (n-N+1).Adopted second-order filter in the utility model, the input and output relation of its filtering is:

Y (n)=h ₀X (n)+h ₁H in x (n-1) formula ₀, h ₁Be filter factor.

Conversion of signals is that the actual voltage signal that records is converted into physical quantity corresponding, and its processing formula is:

U (n)=(v (n)-v ₀V (n) is the voltage signal of input in the)/kv formula, and u (n) is a physical quantity corresponding, v ₀Be zero-point voltage, k _vFor changing amplitude, the zero point of each sensor and amplitude are determined by demarcating in advance.

Attitude algorithm method of the present utility model is:

Set up the carrier position geographic coordinate system north-Dong-ground (being N-E-D), (X-is in the carrier symmetrical plane, points to the carrier movement forward direction by barycenter to be fixed on the carrier coordinate system X-Y-Z of carrier; Y-is perpendicular to the carrier symmetrical plane and point to right-hand; Z-is in the carrier symmetrical plane and perpendicular to the X-axis directed downwards.), see Fig. 2 (carrier is example with the aircraft).

The attitude available support coordinate system of carrier in the space represents that with respect to the motion of geographic coordinate system movement angle is called the attitude angle of carrier.Course angle ψ commonly used, pitching angle theta and roll angle γ were as the attitude angle of carrier during navigation was learned, two coordinate systems overlap (N is corresponding with X-axis, E and Y-axis, D and Z axle) when initial, carrier is around the capable partially ψ angle of D axle (Z), again around horizontal y ' axle pitching θ angle, at last around X subsequently " axle lift-over γ angle.Vector in carrier coordinate system and the geographic coordinate system can be changed mutually by following direction cosine matrix: $C_n^h=\left[\begin{array}{ccc}\cos (N,X)& \cos (E,X)& \cos (D,X)\\ \cos (N,Y)& \cos (E,Y)& \cos (D,Y)\\ \cos (N,Z)& \cos (E,Z)& \cos (D,Z)\end{array}\right]={\left[T_{\mathrm{ij}}\right]}_{3\×3}$ Its subscript b represents carrier coordinate system, and subscript n is represented geographic coordinate system, T _IjBe the capable j column element of i in the matrix.

Three magnetometers respectively along three placements of carrier coordinate system, are measured the projection components of earth magnetic induction density H on three of carrier coordinate system respectively, and establish: the measured value of X-axis magnetometer is x _M, the measured value of Y-axis magnetometer is y _M, the measured value of Z axle magnetometer is z _MThree of degree of will speed up meter respectively along three placements of carrier coordinate system equally, measure acceleration of gravity f respectively _gComponent on X, Y and Z axle, establish: the component of X-axis is x _g, Y-axis component be y _g, the component of Z axle is z _gTerrestrial magnetic field H and acceleration of gravity f _gExpression direction of passage cosine matrix C in geographic coordinate system and attitude frame of reference _n ^hChange, and consider to disturb [e _Mxe _Mye _Mz] T and [e _Gxe _Gye _Gz] ^TInfluence (comprise at random and normal value), resolve formula thereby obtain following attitude angle, wherein H is an earth induction intensity, β is an earth's magnetic dip angle.

The normal value of undesired signal and relevant portion can be eliminated by signal Processing and modeling.

Graphic interface module of the present utility model, user operate the demonstration interface module and all adopt Microsoft Visual C++ software programming to form.

Characteristics of the present utility model and effect:

The utility model is on the basis of aforementioned digital magnetic resistance compass, its structure composition and software algorithm have all been done bigger change, adopt three silicon micro accerometers to constitute inclination sensor, because the acceleration machine can provide the gravitational acceleration component on three vertical direction of the coordinate system that meets at right angles in the three dimensions, so the inclinator of being made up of accelerometer not only can play the effect of carrying out slope compensation for course angle, more can be used as the effective tool of measuring carrier full reclining attitude (referring to any inclination).Set up contact between geographic coordinate system and the carrier coordinate system by the orientation cosine matrix, thereby can calculate pitching, rolling and the course angle of full attitude.In a word, the related miniature guider of the utility model is that multiple MEMS sensors such as collection silicon micro accerometer and magnetometer are one, can access the full attitude information of motion carrier by the algorithm process in the utility model.The inertia device (as inertia gyroscope) of employed MEMS device in the conventional inertia guider in this device has characteristics such as structure of whole solid state, volume are little, in light weight, low-power consumption, startup is fast, cost is low; This device all is being better than the HMR3000 of U.S. Honeywell company on the function and on the performance, as can realizing the measurement of full attitude, and when environmental activity field size changed, this device still had robustness preferably; In addition, this device also make high precision full attitude (comprise little, in, wide-angle) be achieved in measuring.

Brief Description Of Drawings:

Fig. 1 is existing digital magnetic resistance compass structure and principle of work synoptic diagram.

Fig. 2 is carrier coordinate system of the present utility model and geographic coordinate system relativeness synoptic diagram.

Fig. 3 is general structure of the present utility model and principle of work synoptic diagram.

Fig. 4 is a software module general structure block diagram of the present utility model.

Fig. 5 is the circuit structure schematic diagram of embodiment of the present utility model.

Fig. 6 is the graphical display manipulation interface synoptic diagram of embodiment of the present utility model.

The utility model constitutes miniature guider based on the MEMS device and reaches embodiment in conjunction with the accompanying drawings and be described in detail as follows:

Hardware architecture of the present utility model and principle of work are as shown in Figure 3, wherein, comprising: 3 axis MEMS accelerometer and peripheral circuit thereof, three reluctance type magnetometers and peripheral circuit thereof, magnetic reset circuit, mu balanced circuit, A/D conversion, microprocessor (CPU) and RS232 standard serial communicating circuit.Wherein, three axis accelerometer and three axis magnetometer are made up of three paths of independent acceleration transducer and three paths of independent magnetoresistive transducer respectively, can measure acceleration of gravity and the magnetic field of rectangular coordinate system three orthogonal directions X, Y, Z in the three dimensions respectively; The magnetic reset circuit is in order to eliminate the influence of environment highfield effect to transducer sensitivity; The power supply that mu balanced circuit is converted into 5V with external 6 ~ 15V power supply unification is access device again; The analog quantity that sensor is exported in the A/D conversion is converted into 12 digital signal, by the parallel reading into the microprocessor (CPU) of data bus; CPU accepts after the sensor signal, is handled by the software module that is stored in CPU and the PC.

Software program general structure of the present utility model as shown in Figure 4, its software comprises: sensor signal merges (comprising filtering, conversion), attitude algorithm, graphic interface, the user operates application software modules such as demonstration interface; Its step comprises: signal is carried out the signal fused of digital filtering, physical quantity conversion, and carry out resolve (above process is all finished) of attitude angle in CPU; The angle that calculates can adopt the interface module of RS232 standard serial to output on the PC to show, also can be directly used in the control of attitude angle, carry out real-time navigation; Measurement result through smoothing processing with good conditionsi, is promptly carried out smoothly subtle change earlier, and to bigger and than obvious variation smoothing processing in addition not, and the user operates and demonstrates interface module and show on the PC screen at last.

The embodiment of each parts of the utility model and principle of work be as shown in Figure 5: power supply is connected with interface cable, the output that this moment, microprocessor began to gather No. three accelerometers (present embodiment is made up of the IC301 that is numbered U10 and U12 of two twin shafts) and No. three magnetometers (present embodiment is made up of the M102 that is numbered U8 of a twin shaft and the M101 that is numbered U9 of a single shaft), wherein accelerometer signal need be passed through voltage follower (present embodiment adopts the TL404 that is numbered U11) and connect the influence of load to its signal after being eliminated, and No. three magnetometer output signals need respectively to be numbered U5 through three, U6, the AD863 of U7 (reference voltage of 2.5V wherein is provided for AD863 by the D025 that is numbered D2) amplifies; The output of No. six sensors enters microprocessor (present embodiment adopts the Intel8052 that is numbered U21) by A/D conversion (present embodiment adopts the BB567 that is numbered U22), carrying out filtering, conversion, angle in microprocessor resolves and obtains three attitude angle, this attitude angle is by RS232 communication (present embodiment adopts the TL202 be numbered U23), uses simple ASCII instruction character string to carry out communication with PC; At this moment, on the screen of PC, message block will occur, show the reading of current attitude angle and embody current attitude by figure.

Except that the basic function of above-mentioned introduction, device also is numbered the external power supply process 78D05 voltage stabilizing of UD3; In the magnetometer reset circuit, feed field effect transistor (present embodiment adopts the ICL6054 that is numbered U13) by the two-way pulse width signal and produce periodic positive and negative heavy current pulse, size of current is controlled by the output voltage size of the N7011 that is numbered U14 (N7011 converts the 5V supply voltage to desired voltage, requires voltage to adopt 12V in the present embodiment).Pulse current is by magnetometer, and magnetic resistance can recover normal working sensitivity under the positive and negative big function of current.

The graphical display manipulation interface of present embodiment as shown in Figure 6, the upper left corner is the output of No. six sensors among the figure, the upper right corner is attitude graphic presentation, it below the figure data presentation of attitude angle, also be provided with the button that " beginning " of startup, stopping device and " end " button and control are demarcated, resetted in the interface.

Present embodiment can be realized full attitude measurement, and promptly angle of pitch measurement range is-90 °～+ 90 °, and the rolling angle measurement scope is-180 °～+ 180 °, and the course angle measurement range is 0 °～360 °; Can guarantee the stability of measuring accuracy in full attitude measurement scope, angle-measurement accuracy is: course and pitch angle error are all less than 1 °; Can be adapted to the attitude measurement (as magnetic field and the uncertain or unsettled situation of gravity field amplitude) in unstable or the uncertain applied field.Present embodiment adopts the integrated encapsulation technology of integrated MEMS chip, makes instrument miniaturization more, and its vibration resistance and overload resistance are improved, thereby makes instrument can adapt to application under the various rugged surroundings.

Claims (1)

1, a kind of miniature guider based on micro-electromechanical technology, comprise a plurality of sensors, the A/D converter that the signal that this sensor is recorded is changed, the microprocessor that the digital signal of this A/D converter output is calculated, the RS232 standard serial mouth that microprocessor is linked to each other with PC, it is characterized in that, said sensor is made up of three silicon micro accerometers and peripheral circuit thereof and three axis magnetometer and peripheral circuit thereof, and is stored in signal Processing and software for display module in said microprocessor and the PC in advance.

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