CN102116629A - Method of configuring six micro mechanical electronic gyros based on regular tetrahedron - Google Patents

Abstract

The invention discloses a method of configuring six micro mechanical electronic gyros based on regular tetrahedron. The method uses six single degree-of-freedom micro mechanical electronic gyros, employs a regular tetrahedron, instead of the conventional regular dodecahedron, to form a non-orthogonal configuration, and derives the measuring equations, the detecting equations of the regular tetrahedron, finally realizes the fault detection, isolation and identification of the gyros, and improves the system reliability. Compared with the traditional oblique crossing configuration scheme of the regular dodecahedron, the configuration scheme of the six micro mechanical electronic gyros based on a regular tetrahedron is easier to realize, and the detection of three gyros in failure can be realized. By adopting the method in an inertial navigation system, the design of the structure can be fairly simple. And because the gyros only need to be installed along six arrises of the regular tetrahedron, the method has greater application value.

Description

A kind of six micromechanics electronic gyroscope collocation methods based on positive tetrahedron

Technical field

The invention belongs to the Navigation, Guidance and Control technical field, particularly relate to a kind of six micromechanics electronic gyroscope collocation methods based on positive tetrahedron.

Background technology

Gyro is the critical elements in the inertial navigation system, in order to the angular motion of measuring machine system with respect to inertial system, thereby determines the attitude of carriers such as aircraft, guided missile, and provides foundation along the measured value that navigation coordinate system decomposes for accelerometer.Inertial Measurement Unit is a kind of very important equipment in the Navigation, Guidance and Control system, it is made up of three gyroscopes and three accelerometers, requirement according to the inertial navigation principle, three gyrostatic sensitive axes are mutually orthogonal and parallel with three corresponding carrier coordinate axis respectively in twos in the space, measures the input angular velocity of three carrier coordinate axis.Do not rely on external information during Inertial Measurement Unit work,, be not vulnerable to external interference, this unique features not to extraneous emittance yet, make it become carrier, a kind of widely used main air navigation aid of carrier in especially space flight, aviation and the navigation field.

Along with science and technology development, from engineering viewpoint, littler device, littler structural unit even littler subsystem have shown special advantages in many aspects, can satisfy the requirement of a lot of special occasions and function.So in recent years, along with micro-fabrication technique and micromechanics development of electronic technology, micromechanics electronic gyroscope of new generation develops rapidly, their volumes are little, in light weight, cost is low, have the many unrivaled advantages of traditional gyroscope.By the micro-miniature inertial measuring unit that the micromechanics electronic gyroscope is formed, having satisfied with space flight, aviation and navigation is the very urgent and outstanding demand of large quantities of miniaturization carriers of occurring in the field of representative.

Modern sail body has proposed more and more higher requirement to accuracy of navigation systems and reliability, but only depends on the design that improves parts and manufacture level improves precision and reliability is very difficult.Therefore,, adopt redundancy technology to improve reliability, become the direction of airmanship development along with control theory and development of computer.In strapdown inertial navigation system, gyro directly connects firmly on body axis system, therefore be convenient to adopt redundancy technology, a plurality of gyros are carried out nonopiate installation, to obtain a plurality of repeated measures of carrier angular motion, and detection from measured value, identification and isolated fault gyro, thereby make navigational system obtain higher reliability.

Traditional six gyro allocation plans based on regular dodecahedron are that the sensitive axes of six single-degree-of-freedom gyros is installed along the normal direction on six planes of regular dodecahedron, whenever are positioned at body axis system OX with a pair of measurement axis _bY _bZ _bA coordinate plane, then the angle of sensitive axes and coordinate axis is α=31 ° 43 ' 2.9 ", as shown in Figure 1.Littler in order to obtain volume, weight is lighter, the simple more remaining collocation method of structure adopts series of advantages such as the price that it has based on the minisize gyroscopes of micromechanics electronic technology manufacturing is low, power consumption is little, volume is little, and it is more suitable in carrying out the redundance configuration.Therefore, be necessary to propose six micromechanics electronic gyroscope allocation plans based on positive tetrahedron relatively simple for structure.

Summary of the invention

Fundamental purpose of the present invention is to provide a kind of remaining collocation method in conjunction with the characteristics of micromechanics electronic gyroscope, make its structure simpler, to obtain a plurality of repeated measures of carrier angular motion, and detection from measured value, identification and isolated fault gyro, thereby make navigational system obtain higher reliability.

For achieving the above object, technical scheme of the present invention is achieved in that

A kind of six micromechanics electronic gyroscope collocation methods based on positive tetrahedron, this method may further comprise the steps:

(1), its sensitive axes is installed along six ribs (being six foursquare six diagonal line in surface in the regular hexahedron) of positive tetrahedron, as shown in Figure 2 for each single-degree-of-freedom micromechanics electronic gyroscope;

(2) when the equal operate as normal of all gyroscopes (or performance is within required scope), the value of all parity equations is zero (or being approximately zero);

(3) lost efficacy or performance when obviously descending when certain gyro, the parity equation that comprises this gyro then no longer is zero.Like this, by well-organized above-mentioned a series of parity equations, the detection equation in the time of can writing out, two or three gyros respectively and lost efficacy, thus can realize differentiation to the inefficacy gyro.

Principle of the present invention is: among Fig. 2, coordinate system OXYZ is the body coordinate, mi (i=1,2 ..., 6) be the measured value of i gyro, the direction of arrow is its sensitive axes direction.Under this configuration, each gyro can sense the superposition value of both direction moment of momentum.With m1 is example, has

$m1=\frac{\sqrt{2}}{2}{\mathrm{\ω}}_x+\frac{\sqrt{2}}{2}{\mathrm{\ω}}_y$

ω wherein _x, ω _yBe respectively body system with respect to the angular velocity of inertial system component at x axle and y axle.Thereby 6 micromechanics electronic gyroscopes are listed as respectively to write to be measured equation and can obtain

m＝Hω

Wherein, m=[m1, m2, m3, m4, m5, m6] ^T, ω=[ω _x, ω _y, ω _z] ^T, H is that 6 row, 3 row are measured matrix.

By following formula as can be known, any one, two or three gyros lost efficacy and promptly can't obtain measured value, all can be by the unique definite ω of remaining gyro _x, ω _y, ω _z

According to each gyro and measured value, also can write out a series of parity equations of gyro under normal operation, such as

(m ₁-m ₂)-(m ₃+m ₄)＝0

(m ₁+m ₂)-(m ₃-m ₄)＝0

When certain gyro lost efficacy or performance when obviously descending, the parity equation that comprises this gyro then no longer is zero.Like this, by well-organized above-mentioned a series of parity equations, the detection equation in the time of can writing out, two or three gyros respectively and lost efficacy, thus can realize differentiation to the inefficacy gyro.Can draw as drawing a conclusion by summing up the detection equation:

1, the situation that any single gyro was lost efficacy all can detect, discerns and isolate

2, the situation that two gyros were lost efficacy, except that special circumstances, the overwhelming majority can detect, discerns and isolate

3, the situation that following three gyros of particular condition were lost efficacy also can detect, discerns and isolate.

The present invention has following advantage:

1, simple in structure.Being about to gyro installs along six diagonal line (being the rib of regular hexahedron) of positive tetrahedron.

2, the situation that following three gyros of particular condition were lost efficacy also can detect, discerns and isolate

Description of drawings

Fig. 1. based on six gyro allocation plan principle schematic of regular dodecahedron.

Fig. 2. based on six micromechanics electronic gyroscope allocation plan principle schematic of positive tetrahedron.

Fig. 3. fault detect, isolation and reconfiguration program process flow diagram.

Embodiment

Specific implementation step of the present invention comprises: hardware is realized, software is realized, module connects.

(1) hardware of remaining system is realized:

In the remaining system prototype of research, use the micromechanics electronic gyroscope of 6 single-degree-of-freedoms, six rib oblique configurations along positive tetrahedron, in the two CPU navigational computers of miniaturization used herein, single-chip microcomputer uses the C8051F021 of CYG-NAL company, DSP uses TI company's T M S320C5416 to guarantee the existing stronger control function of navigational computer, and stronger data operation processing power is arranged again.The host interface of DSP inside (HPI) has then guaranteed data communication reliably at a high speed between two CPU.

(2) software of remaining system is realized

Redundancy technology is a kind of effective way that improves the strapdown inertial navigation system reliability, should have the function of " fault detect ", " Fault Identification ", " system reconfiguration ".

The software of remaining system failure detection scheme is realized: adopt ripe method promptly to utilize the parity equation formula to carry out the parity checking method of fault detect.In the positive tetrahedron layout, use the linear dependence relation between 6 measured values, can list the parity equation formula.If all gyros are operate as normal all, then all the parity equation formula can both satisfy.If gyro failure occurs, then corresponding parity equation formula just is false.In the native system, when 1 gyro or 2 gyros inefficacies, can detect and discern the fault gyro exactly; When the gyro more than 3 or 3 lost efficacy, under specific circumstances, the system that also can detect was out of order, and discerns.

The software of remaining system reconfiguration scheme is realized: the complete program flow diagram of remaining system as shown in Figure 3.

(3) remaining configuration software module is connected with small-sized navigational computer software module

After having write 2 subroutines of fault detect and system reconfiguration, need be transplanted in the built-in C language of single-chip microcomputer, and with the software module of small-sized navigational computer (as, lower floor's software such as the data acquisition of IMU, data transmission, hardware bottom layer configuration and navigation data upper layer software (applications) such as resolve) be connected, constitute the angular motion measuring system of a complete Redundant Inertial Navigation System.

Claims (1)

1. six micromechanics electronic gyroscope collocation methods based on positive tetrahedron, it is characterized in that: described six micromechanics electronic gyroscope collocation methods based on positive tetrahedron comprise the following step that carries out in order:

(1), its sensitive axes is installed along six ribs (being six foursquare six diagonal line in surface in the regular hexahedron) of positive tetrahedron for each single-degree-of-freedom micromechanics electronic gyroscope;

(2) when the equal operate as normal of all gyroscopes (or performance is within required scope), the value of all parity equations is zero (or being approximately zero);

(3) lost efficacy or performance when obviously descending when certain gyro, the parity equation that comprises this gyro then no longer is zero.Like this, by well-organized above-mentioned a series of parity equations, the detection equation in the time of can writing out, two or three gyros respectively and lost efficacy, thus can realize differentiation to the inefficacy gyro.

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