JPS5860213A - Device and method of detecting physical characteristic - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for detecting physical characteristics. In particular, the present invention relates to a device capable of detecting parameters such as angular velocity, linear acceleration, magnetic field orientation, electric field orientation, and airflow data. Currently, there are multi-sensor devices, ie, multisensors, that measure the parameters of lift. This specific device was issued to Rowland Pitman on April 16, 1980. U.S. Patent No. 41) for “Multiple Detection Apparatus and Apparatus for Multiple Detection”? No. 7787 KN is shown. Based on this patent, some details are described below.

FIG. 1 shows a device 10 and a suitable demodulator 12. FIG. The device io is basically made of piezoelectric material and vibrates a bipolar check 6 of L@. It consists of a rolling shaft 14 extending in the radial direction and having 92 arms. When a physical change is applied, the two arms deflect, producing a piezoelectric electromotive force corresponding to the degree of this deflection. Its output is taken from the multisenna by means of a sliding ring (not shown).

The multi-sensor described above detects the speed and negative acceleration by rotating the piezoelectric generating element around the motor rotation axis. By properly coupling the piezoelectric generators, their responses can be minimized for a desired input and maximized for a desired output. It occurs on the surface of the dipole when the axis is rotating. Any acceleration applied.

That is, the linear acceleration in the case of an acceleration sensor or the Coriolis acceleration in the case of a rotational speed sensor.

cas(ωat) to produce a rotational speed signal whose magnitude is proportional to the applied acceleration. Here, 0
The mouth closes at the angular velocity of rotation. However, when a twice the disturbance input occurs and a rotational speed (2ω-) is added, it will produce a rotational speed output signal that is indistinguishable from the desired input. If there are any defects or imperfections in the bearing, it is
There is a risk of generating acceleration and angular velocity that are modulated by the rotating machine.

Moreover, it produces errors that are important to the output. If multiple sensors are purchased from a single dipole, there is no effective way to compensate for these spurious signals.

Since the device of FIG. 1 is not provided with the ability to discriminate the desired input signal from twice the disturbance rotation speed, the multisenna has not been widely applied. Therefore, it is an aim of the present invention to utilize the basic principles of multi-sensors that are not susceptible to bearing noise and other errors that can result in mt-skew output signals.

The present invention overcomes the deficiencies of the multi-sensor disclosed in US Pat. No. 419'Z787 by incorporating a second dipole disposed perpendicular to the first dipole.

For convenience, the first dipole is named a real dipole, and the second dipole is named a virtual dipole. These dipoles are indicators of a rotating coordinate system. The added companion, ie, the virtual dipole, provides an additional source of information that, when demodulated, allows for accurate reconstitution of the information originally provided to the multisenna.

For a better understanding of the invention, as well as other objects, please refer to the following explanation made in connection with the stock illustration:
Reference ranges will be pointed out in the claims.

The invention and the demodulation circuit forming part of the invention are illustrated in FIG. A modified nine multi-sensor 20 is shown in FIG. Almost identical to the prior art multi-senna lO. The multi-sensor 20 is made of piezoelectric material and has 9 axes 2
It has 21IiI dipoles 22 and 24 mounted on 8. The mechanical details of the multi-sensor 20 are similar for purposes of its construction to those of a multi-sensor with a single dipole. The details on the i-groove are fully disclosed in U.S. Patent No. 4.19-787 and will not be repeated herein.

No. 29 also demodulates the signal in the form of a block diagram.
The circuit required for j8 is illustrated. The demodulation process is similar to that used for multisensors with dipoles of L@, with some differences. The demodulation process is
Further details will be revealed.

The following analysis is necessary to understand the operation of a multi-sensor with a 2fil dipole.

For the amplitude AK with phase angle φ at time 1-0,
Angular velocity ω of the multi-sensor in the XY plane. Assuming a disturbance that draws a sire curve, the amplitude of the disturbance is given by the following equation. Namely.

D=A■ (ω, is 1φ) (1) If the disturbance occurs in the direction of the line at an angle θ with respect to the X-axis of the sensor, the disturbance in the X-axis direction is D! “DQIIθ
(2) becomes. Mafcs'r
The axial disturbance is.

D,=D θ (3).

Combining equations l and 2 for the X-axis component of the disturbance,
Equations l and 8tl for the Y-axis component of the disturbance are combined and rearranged.

nx=(■(ω, t+φ+θ) billion(ω, t+φ−θ)
) (4) D! =mu(dn(ωB1+φ+θ)−t
h(ω, 1+φ−θ)) (5) is given.

The sensor is orthogonal to the pivot axis.

Assume that they are one-to-zero dipoles (referred to as real and virtual in Jin) mounted orthogonally to each other, and further define that the real dipole is aligned with the X-axis of the instrument at time 1-0. and a virtual dipole.

It is defined as being aligned with the Y axis of the instrument at time t-π/(201). Here, ω1 is the angular velocity of the rotation axis. As for reality signals.

8th seal - D8α wealth (ωat) + Dyah (ωat)
(6) And regarding virtual signals.

Eft = Dr (ICII(0m t) -Dx
m(a'a t) (7) is given.

Rewrite and organize this.

Sm = A/2(cas(('%-0m),
) t + φ + θ) 10 ((ω. + ωsN + φ-θ) )
(8) S s −A/ 2[dn
((ωp-ω-))t+φ10)-th((-+ωs)
t+φ−θ) ) (9) is given.

To restore the initial long-term information about the X and Y axes, we add dn(ωat) and Cog(ω
It is necessary to multiply these product pairs by multiplying at), obtaining the product of 4@ and combining these product pairs.

X@signal=8.・(2) (ω5t)-8m image (ωat)
(g)Y@double signal 81”COI!(ωs t)+
8s Yu (”a t) CIO and equation (8)
, Substituting (9) and rewriting and organizing.

Regarding the above 2wA signal component.

X signal = A/2 (am(aI!lt+φ10θ)10cm
((alot+φ-θ)]@Y signal-A/2(sin(
t+φ+6)-m<t+φ-θ)](to) is given.

These equations (6) and Ql can be rewritten as follows. Namely.

X signal - Aam (ωD1+φ) cm #
Q4Y signal - Accm(ωD1+φ)m
θ (to) A cos (ω, t
+φ) fJ4 is the disturbance applied to Senna. On the other hand,
■θ and inner θ represent the direction of the disturbance with respect to both axes of the instrument. Equations α4 and (to) are.

Real dipoles and virtual dipoles are used in instruments, and.

After the signal i! Show that when Ml is multiplied by (2), the output represents the input to the instrument. It is impossible for bearing-noise aliasing to enter the quiet bias at twice the rotational speed.

In existing multi-sensors, information is encoded by eleven dipole detectors without relying on the use of real and virtual sensors. Various results obtained by this detector can be obtained by setting the virtual signal to 0 in equations (7) and (b).

X signal-8l”QIl(ω-1)
@Y signal = Sm'5hI (ωat)
Q7) If you rewrite and organize this,
Regarding the signal component of 2@.

i signal - Mu residence (ω. t + φ) - 〇) + Mu (2) ((ω1
2ω1)t+4 is obtained.

Equation [phase] and the first term in 09 are equations a◆ and (
is equal to 1/l of the signal defined by ) and represents the true output of the device. However, this output is corrupted by the second and eighth terms. Paragraph 8 is less important. Because the lowest possible rotation speed is ω! This is because when the rotation speed is 1-0, the rotational speed of the device is 02 times higher. The 8th
The second term in equation (2) and OQ presents difficulties, representing high-speed noise that does not normally affect the system. The second term indicates that a disturbance at 02 times the rotational speed will produce a quiet bias in the output (compared to the instrument's quiet sensitivity) with a sensitivity of 60 inches. Since the influence of bearing noise is 02 times the rotational speed, an instrument configuration that does not utilize both real and virtual dipoles loses QIl@, which is important for its bias stability.

A multi-sensor has an encoder or variable voltage in its entity.
＠Deral. In order to obtain useful information from the multisensor, the output of the dipole is sampled from a slip ring structure (not shown) and processed in a demodulation circuit. The demodulation process is exactly the opposite of modulation and is controlled in its essence by the relationships expressed in equations (1) to (1) above. The signal from each dipole 22 or 2B is fed into a separate channel at -2 in 80 and ε2, respectively. Those signals are first increased by 41! in the 11th stage J1 and 86!
and F wave. Each signal is then simultaneously fed to the 21i demodulator. One signal is normalized at uo.

The other signal is normalized at 90". Mathematically, each signal has cas(ωat) and -(hia
To complete the above demodulation process, the output of demodulator vII 1168B and 42 (actually,
The outputs of demodulator 42 are inverted) are summed in adder 46, and the outputs of demodulator 10 and demodulator 1 false are added in adder 46! 8 is added. Power multipliers and output filters are provided in stages 60 and 62. The outputs of these stages 60 and 52 are:

The X-axis indicator and the Y-axis indicator, as shown mathematically in equations α◆ and ). For steady-state inputs, ω, = 6, and these signals are not time-varying functions.

It should be noted that the voltage is constant.

Theoretically speaking, the 21i dipole multisensor is just one possible form of overcoming the deficiencies inherent in the LII dipole multisensor, which utilizes a two-dimensional system to measure linear acceleration and Any system that samples angular velocity will yield the desired results. For example, 12
The Sennach 2O2 term, which has 98 radially extending arms with 0° spacing, is well distinguishable. Similarly, 72
A senna with 5 arms with a spacing of 5° is also possible.

The corresponding converter requires a suitable reference speed in order to decode the senna output.

In investigating the above problem, it was assumed that the signal from the instrument would undergo a demodulation process by multiplying it by a sine or cosine function.

This demodulation process samples the signal at a high rate, passes it through an appropriate anti-φ aliasing filter, and then performs A/D conversion to produce the resulting signal.

This could in principle be completed by multiplying K by a suitable sine or cosine function stored in the read-only memory 17-(ROM) and directed by a counter in a phase-locked synchronized closed circuit. Information suitable for computer processing can be obtained by simply passing the resulting data through a digital low-pass filter. In order to effectively carry out such pretreatment, A/
To enable multiplexing of D-converters, perhaps 100
KH1! An A/D converter with 16 to 18 bits of accuracy and resolution would be required that could operate in the .

Currently, such converters are highly unlikely to be available.

(Even the accuracy of available analog multipliers is completely inadequate for the above purpose.) Currently, the only means for demodulation operation that seems suitable is a switching demodulator. This switching demodulator uses the signal to the power of t(ω-t) or txs(ω,1) to
It works by multiplying by ±l instead of . When using a switching amplifier, odd high frequency, square wave characteristics will be present in the output, so it will be necessary to filter the F wave.

Although what is believed to be a preferred embodiment of the present invention has been described up to this point, those skilled in the art will appreciate that it is possible to embody other modifications and further changes to this embodiment and still realize the present invention. It will be recognized that no deviation from the essence thereof, and therefore, patent is claimed for all such embodiments that fall within the true scope of the invention.

[Brief explanation of the drawing]

FIG. 1 is an illustration of the multi-sensor and suitable demodulation circuit disclosed in U.S. Pat. No. 41.theta.7787. FIG. 2 is according to the present invention. A new page includes an explanatory diagram of a multi-sensor and a demodulation circuit corresponding to this multi-sensor. 20...Multi-sensor, 22...First dipole, 24
... ° second dipole, 26 ... rotation axis, 28 ... demodulation means. 88...First synchronous demodulator, 40...Second synchronous demodulator, Arc 2...Eighth synchronous demodulator, Trace 4...-4th synchronous demodulator u
Vessel, 8... adder, 48... adder. FIG, 1 0 FIG, 2

Claims (1)

[Claims] (1) Consists of a rotating shaft and two piezoelectric crystal arms. A first coupled to the rotating shaft at an intermediate point and producing a signal output.
a second dipole angularly displaced with respect to the first dipole, comprising a dipole and two piezoelectric crystal arms, coupled at a midpoint to the rotational axis and producing a signal output; , and demodulation means. (2) The detection device according to claim 1, wherein the first dipole and the second dipole are arranged in a plane perpendicular to the rotation axis. (3) The detection device according to claim 2, wherein the second dipole is arranged at an angle of 90° with respect to the first dipole. (4) The detection device according to claim 8, wherein the first dipole and the second dipole exist within a 41 plane. (51) The detection device according to claim 1, comprising a vector ring for output supply coupled to the first dipole and the second dipole. Detection device according to item 6. (7) The above (31I modulation means include a first synchronous demodulator, a second synchronous OL modulator, and an eighth synchronous OL modulator, each of which has a signal input terminal, a reference input terminal, and a signal output terminal. Synchronous demodulator and arc synchronizer, with phase normalized to υ°
a first signal generator that generates an l signal, a second signal generator that generates a second signal having a phase normalized to 90 degrees, and an in-phase input terminal, an anti-phase input terminal, and an output terminal. a first adder having a first in-phase input terminal, a second in-phase input terminal and an output terminal, the output terminal of the first dipole being connected to the first synchronous converter G4 and The output terminal of the second dipole is connected to the input terminal of the second synchronous demodulator, the output terminal of the second dipole is connected to the eighth synchronous demodulator, and the output terminal of the first signal generator. is connected to one of the reference input terminals of the first intermittent demodulator and the fourth synchronous demodulator, and the output terminal of the second signal generator is connected to one of the reference input terminals of the second synchronous demodulator and the eighth synchronous demodulator III. connected to the reference input terminal, and connected to the first input terminal.
The output terminal of the synchronous demodulator is connected to the in-phase input terminal of the first adder 1, the output terminal of the WJ2 synchronous demodulator is connected to the first in-phase input terminal of the second adder p, The output terminal of the eighth adder is connected to the third adder.
Connected to the above-mentioned negative phase side input terminal of the I-device, and the above-mentioned first synchronization *
7. The detection device according to claim 6, wherein the output terminal of the tS generator is connected to a second in-phase input terminal of the second adder. (3) comprising a rotating shaft, a first arm, a second arm, and an eighth arm made of a piezoelectric material and attached to the rotating shaft while protruding perpendicularly to the rotating shaft, and demodulating means; 120 for each of the other arms.
Detection device placed at an angle of °. (9) generating an output signal from the first dipole by rapidly rotating the first dipole made of piezoelectric crystal material around an axis of rotation perpendicular to the dipole at its midpoint; and a second dipole made of a piezoelectric crystal material, which is angularly displaced with respect to the first dipole at an intermediate point thereof, is rapidly rotated around the axis of rotation at the intermediate point thereof. A method for detecting linear acceleration and angular velocity, comprising the steps of generating an output signal from a dipole, and demodulating the output signal of the first dipole and the second dipole. (G) The demodulation step includes a step of generating a first * generating an eighth demodulated signal and a first demodulated signal by synchronously demodulating the output of the dipole with a phase reference of 0'' and 90°, and inverting the eighth demodulated signal; a step of generating an X output by adding the first demodulated signal and the inverted eighth demodulated signal; and a step of generating a Y output by adding the second demodulated signal and the fourth demodulated signal. Claim No. 9
Thin acceleration and angular velocity detection method described in . O]) A method for measuring acceleration and angular velocity of an object, having a pivot axis coupled to at least two non-parallel axes, said at least two axes being substantially perpendicular to said pivot axis.