JPS6341490B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an azimuth display method used in a general navigation vehicle to know the direction of travel, or azimuth, of the navigation vehicle, and a gyro device for implementing the method.

In general, all navigation vehicles have their direction of travel,
That is, it is desirable to have a means of knowing the direction, and for this purpose, well-known magnetic compasses with a magnetic needle pointing north and south of the earth's magnetic field have been widely used for this purpose. However, when the magnetic compass is tilted from the horizontal, it is sensitive to the vertical component of the earth's magnetism and causes an error. Therefore, in a normal navigation vehicle that is subject to oscillation, the magnetic compass constantly swings its head from side to side, giving no indication of its direction. It is a well-known fact that it has the drawback of being unstable, and many inventions and ideas have been made to improve it since ancient times.

Shortly after entering the 20th century, when it became possible to technologically utilize the Gyroscope, the spin axis of the Gyroscope was moved around the Earth by using the Earth's rotation, gravity, and the properties of the Gyroscope, without using the earth's magnetism at all. A gyroscope compass that aligned with the meridian was invented,
This is currently widely used on ships, but it is also unsuitable for high-speed vehicles because it increases errors related to speed, and its northward motion has a long period of several tens of minutes. Because of the problem that it cannot be used until several hours after the switch is turned on, it is only used on ships that make long-distance voyages, and is not used on a wide range of general navigation vehicles such as aircraft, hydrofoils, and vehicles such as automobiles. Not yet.

On the other hand, in airplanes, a method of equipping a free-gear gyro alongside a magnetic compass has come into widespread use. In other words, during a sudden change in attitude such as a somersault, the magnetic compass suddenly becomes unstable and cannot be used. This is a method of correcting the direction of the freesia gyro using the compass as a reference.

This solved the problem because it could be used immediately after turning on the switch, but the Freesia Gyroscope can only be used as a compass for a few minutes at most, and as the earth rotates, the spin axis of the Gyroscope changes over time. This is extremely inconvenient as the gyroscope drifts significantly and the slope changes moment by moment, requiring frequent adjustments to the gyroscope.

In the middle of the 20th century, a device was developed that eliminated the above drawbacks, relied on the properties of the gyroscope to provide stability in direction indication, and, in the long run, controlled the spin axis of the gyroscope to match the direction of the earth's magnetic field. was invented. This is called a geomagnetic slave dozer compass, or a gyroscope compass, which is currently widely used in the military and large passenger aircraft (hereinafter, for simplicity, it will be collectively referred to as the gyroscope). The azimuth pointed by the Gyroscope is not the horizontal plane projection of the Earth's rotation axis (true meridian) like the Gyroscope compass, but the direction of the horizontal component of the earth's magnetic field at that point (magnetic meridian), which in Japan is called the true meridian. It can be said to be a perfect compass for aircraft, except for the drawback that it has an error of several degrees from the meridian.

However, this gyrosine also has many drawbacks when considered to be installed in many other navigational vehicles such as vehicles, and is not put into practical use at all except in high-end aircraft. The first reason is that the unit equipped with the Gyroscope is stored inside the fuselage of the aircraft, but the magnetic sensor that detects the earth's magnetic field is located far away from most iron equipment. It is usually mounted inside the wing tip of an aircraft. However, land vehicles, hydrofoils, hovercraft, etc. do not have wings, and the magnetic environment is similar throughout the vehicle, making it ideal for aircraft wing equipment. Gyrosin's magnetic sensor is specialized and difficult to use. The second reason stems from the first reason, and is related to the exchange of geomagnetic direction between the magnetic sensor on the wing tip of the aircraft and the gyro unit, and the exchange of azimuth between the gyro unit and the direction indicator in the cockpit. However, it is extremely expensive and not common in terms of price.

Therefore, the first object of the present invention is to provide a direction display method that eliminates the drawbacks of the above-mentioned gyroscope, and a gyroscope device for carrying out the same. The purpose of the present invention is to provide a azimuth display direction that can be used in general vehicles such as hovercraft, aircraft, etc., and a gyro device for carrying out the same.
In the short term, the direction indication is stable by using the properties of the gyroscope, and in the long term, there is no drift based on the geomagnetic direction, and moreover, compared to the gyroscope, the direction indicating method and its method are significantly cheaper. The object of the present invention is to provide a gyroscope device that performs the above operations.

Hereinafter, before describing the present invention in detail, gyrosin will be explained with reference to FIG. 1, and then the present invention will be explained and the merits of the present invention will be clearly explained by comparing with FIG. do.

FIG. 1 is an explanatory diagram for explaining the principle of gyrosin. In the figure, reference numeral 1 denotes a gyro rotor, which is supported by a gyro case 2 so as to be rotatable around its spin axis. The gyro case 2 has concentric shafts 3 on both sides,
3', and these shafts 3, 3' are rotatably supported by a gimbal 5. Note that the line passing through the center of the axes 3 and 3' will be referred to as the horizontal axis in the following text. The horizontal axis is perpendicular to the spin axis of the gyro rotor 1. The gimbal 5 has axes 4 and 4' above and below. Although the shafts 4 and 4' are omitted in Fig. 1,
It is rotatably supported by a panel 9 shown in FIG. The line passing through the center of the axes 4, 4' will be referred to as the vertical axis in the following text. This vertical axis is orthogonal to the horizontal axis. A torquer 10 is directly connected to the shafts 4, 4', and this generates a torque on the panel 9 to rotate the gimbal 5 around the shafts 4, 4'.
In the example shown in Fig. 1, the torquer 10 is of the AC two-phase type, its terminals 10' and 10'' are fixed phase, and the AC power supply 19' (400Hz is normally used in aircraft).
connected directly to. The control phase, on the other hand, is connected to a known electrolyte level or slope detector 8 and to an AC power source 19, as shown, to form a bridge circuit. Electrolyte level 8 is gyro case 2
(separated in the figure), and the direction of movement of the electrolyte is along the spin axis.
The power supply 19 is naturally synchronized with the power supply 19',
Only the phase is assumed to differ by approximately 90°. When the gyroscope case 2 is tilted, the internal resistance within the electrolyte level 8 becomes unbalanced, and the torquer 10 responds accordingly.
produces a torque around the vertical axis and the gimbal 5
However, due to the presence of the gyro, the gimbal 5 does not rotate around the vertical axis; instead, the spin axis of the gyro is rotated by the preset around the axes 3 and 3'. Change your posture. This makes the spin axis horizontal,
When the internal resistance of the electrolyte level 8 is balanced, the torque generation of the torquer 10 stops, and the presetting of the gyro also stops. That is, the device consisting of the electrolyte level 8, the power source 19, and the control winding of the torquer 10 is a device for automatically raising the gyro case 2 (keeping it horizontal).

As will become clear later, the gist of the present invention has nothing to do with this automatic erecting device, so a brief explanation will be provided in this regard.
Incidentally, as the electrolyte level 8, those having various known structures can be used, and a mercury switch may also be used.

In FIG. 1, 12' generally indicates a geomagnetism detector. This is a known flux valve (also called flux gate) transmitter, and its excitation winding 12'-1 is connected to an AC power source 19''. The secondary windings 12'-2, 12'-3 and 12'-4 are
According to the known flux valve principle, an alternating current voltage is output whose frequency is twice that of the power source 19'' and whose amplitude is proportional to the magnitude of the earth's magnetic field linked to the respective winding.This secondary winding 12' -2,1
The three-phase output consisting of 2'-3, 12'-4 is received by a high impedance control transformer 12''. ″
-4 vector-synthesizes the received three-phase outputs of the flux valve 12' within the stator, so the stator of the control transformer 12'' contains two
At double frequency, AC magnetic flux vectors with a certain direction are synthesized, and the direction is 1:1 with the direction of the earth's magnetic field.
Take action. Therefore, control transformer 1
2'' rotor winding 12''-1 will have a maximum voltage when it is fully linked with the above-mentioned resultant AC flux vector, and when the rotor is turned at right angles from this position, it will no longer be linked with the magnetic flux. The generated voltage becomes zero. In other words, the relationship between the flux valve 12' and the direction of the earth's magnetic field is as follows, with the stator of the control transformer 12'' in relation to the rotor.
Therefore, the rotor of the control transformer 12'' is directly connected to the azimuth axis 4' of the gyro, and the output of the winding 12''-1 is transmitted through the amplifier 13. The torquer 14 is directly connected to the shafts 3 and 3'.
In addition, if the gyro is caused to preset around the shafts 4 and 4', the gyro will preset to the direction where the voltage generated in the winding 12''-1 becomes zero and stop there. , Gyrosin creates a 1:1 correspondence between the geomagnetic direction and the Gyrospin axis direction,
The flux valve 12' and the control transformer 12'' are installed on the same body of the vehicle, and first, the control transformer 12'' and the control transformer 9 are connected so that the geomagnetic direction and the gyro spin axis direction match.
By adjusting the relative angle to the earth's magnetic field, you can always keep the spin axis of the gyro parallel to the earth's magnetic field even if the vehicle changes its orientation with respect to the earth's magnetic field.

Actually, since the fixed phase of the torquer 14 uses an alternating current synchronized with the power supplies 19, 19', and 19'', the amplifier 13 converts the voltage generated by the winding 12''-1 to 1/2 frequency. A circuit is used that modulates the current at the same frequency as the power supply 19 to 19'' after synchronously rectifying it to DC, but theoretically the fixed phase of the torquer 14 is synchronized with the output of the control transformer 12''. If you use an AC (double frequency power supply such as the power supply 19) power source and have an appropriate phase difference with respect to the output of the control transformer 12'',
The amplifier 13 may be a simple amplifier.

In addition, since the entire flux valve 12' is suspended like a physical pendulum with the upper support, even if the aircraft is tilted, the flux valve 12'
is designed to pick up the horizontal component of the geomagnetic field almost correctly, except for transient phenomena.

The control transformer 12'' has a preferable system, as described above with reference to FIG. In other words, as the flux valve 12' swings like a physical pendulum when the aircraft it is equipped with makes a sharp turn or changes its attitude, it picks up the vertical component of the earth's magnetic field and responds to the transient error signal generated. However, because the gain of that loop is low, the response of the gyro is very small and does not cause any problematic errors.In fact, due to the gyro's direction retention ability, it tries to continue pointing in the direction before the attitude change. Therefore, it is extremely accurate in the short term.On the other hand, in the long term, if the direction of the wheel deviates from the geomagnetic direction due to the drift of the wheel, the torquer 1
4 continues to output torque and the spin axis of the gyro is slowly aligned with the geomagnetic direction, so the drift of the gyro is automatically corrected and there is no need for manual correction.

In an aircraft, it is necessary to display the direction so that it can be easily seen from the pilot's seat, but it is important to incorporate a compass card attached to the extension of the axes 4 and 4' into the front of the pilot's seat so that it can be seen easily from the pilot's seat. This is impossible because the card cannot be tilted due to its structure. Therefore, newly added on the shafts 4 and 4',
A synchro oscillator 20 is installed, and its output is indicated by the broken line 2.
Control transformer 21 in the indicator indicated by 9
is received at the stator winding 21' of the rotor winding 21'.
is applied to the control phase of the two-phase servo motor 24 via the amplifier 23, and the rotation of the servo motor 24 is controlled via the gear train 25 to the control phase of the rotor winding 2.
1', the rotor is rotated, and the compass pointer 26 attached to the rotor of the control transformer 21 is turned, so that the voltage generated at the rotor winding 21' of the control transformer 21 is always almost zero by this servo loop. The pointer 26 is rotated to remotely indicate the geomagnetic direction, and the indicator 29 is made compact.
This is installed at an angle within the front control panel,
This makes it extremely easy to see for the pilot. In addition, for the indicator 29, the unit surrounded by the broken line 28 is the directional dial unit.
The part surrounded by the broken line 27 is called a flux valve unit, and the gyroscope is composed of at least three units.

FIG. 2 is a perspective view showing the structure of an example of the directional air unit 28 described above. In Figure 2, the same numbers are given to the same parts as in Figure 1, and to avoid duplication,
The explanation will be omitted. In addition, in Figure 2, 40
is a brush, 41 is a slip ring, and these are:
This is an electrical circuit device for sending power and control signals from the panel 9 to the gyro rotor 1, torquer 14, etc. still,
Since the friction torque between the slip ring 41 and the brush 40 directly affects the performance of the directional gyro 28 as gyro drift, it is required to be compact and have low friction characteristics, as well as high reliability, which increases manufacturing costs. This is one of the factors.

As explained with reference to Figures 1 and 2, the Gyrocin is able to effectively combine the orientation retention properties of the Gyroscope and the non-divergent properties of the geomagnetic direction, thereby reducing the influence of the turning motion of the aircraft on which it is installed. It can be removed and has become an essential instrument for aircraft, etc.

However, Gyroshin requires an electrolyte level and a torquer to hold the spin axis of the gyro horizontally, and a slaving torquer on the azimuth axis and a low-friction slip spring to supply power to the gyro rotor. etc., and the need to increase the angular momentum of the gyroscope in order to reduce the influence of the friction of the slip spring, making the device itself large and extremely expensive, making it unsuitable for aircraft use. Although conveniently constructed, it has drawbacks that make it unsuitable for navigational vehicles other than aircraft. Therefore, as described above, the present invention eliminates these drawbacks and provides a new, inexpensive, highly reliable, and highly accurate direction display method suitable for many navigational objects such as ships and vehicles, and a method for implementing the same. The present invention aims to provide a gyro device that does the following.

The azimuth display method according to the present invention is characterized by obtaining an output corresponding to the azimuth of the navigation vehicle using a uniaxial degree-of-freedom gyro whose input shaft is arranged in the vertical axis direction with respect to the navigation vehicle, and including the information included in the output. removing a steady error component caused by the drift of the gyro, etc., and calculating the azimuth of the navigation object by the gyro based on an output corresponding to the azimuth of the navigation object that does not include the steady error component; The magnetic azimuth output of the navigation object is compared with the calculated azimuth, the comparison output is used to correct the azimuth determined by the gyroscope, and the corrected azimuth is displayed as the azimuth of the navigation object. exist.

Further, the gyroscope device according to the present invention is characterized by a uniaxial degree of freedom gyroscope whose input shaft is arranged in a direction perpendicular to the navigation object, and a geomagnetic azimuth installed on the navigation object to detect the geomagnetic direction of the navigation object. After eliminating the steady error component caused by the drift of the gyro included in the detection device and the output of the gyro, the azimuth of the navigation object is calculated by the gyro based on the output of the gyro. an arithmetic section having a section for comparing the azimuth with the output of the geomagnetic azimuth detection device and a section for correcting the azimuth output of the navigation object by the gyroscope using the comparison output; and a display for displaying the corrected output of the arithmetic section as the azimuth. It is based on this.

Hereinafter, with reference to FIGS. 3 and 4, an example of an orientation display method according to the present invention having the above-mentioned characteristics and an apparatus for implementing the same will be described.

In Fig. 3, 101 is a uniaxial degree-of-freedom gyro, which is fixed so that its input axis coincides with the turning axis (vertical axis) of a general navigation vehicle whose direction of movement, or azimuth, is to be detected. be done. As the uniaxial degree-of-freedom gyroscope 101, a rate gyroscope having a restoring torque generating device such as a torsion bar around its output shaft and whose output is approximately proportional to the input angular velocity is most suitable because of its simple structure and low cost. If high precision is required, a rate integrating gyroscope having an electric torquer around the output shaft of the gyroscope, a laser gyroscope, etc. can also be used. In the following explanation, it is assumed that a rate gyro is used as the gyro.

The output corresponding to the angular velocity of the navigation object from the gyro 101 is input to the A/D converter 102,
After being converted into a digital signal _φ〓v , it is input to the drift compensation calculation unit 106 in the calculation unit 105, thereby removing the steady error component caused by gyro drift and the like contained therein.
On the other hand, the output of the flux valve 103, which is installed in the navigation vehicle and detects the geomagnetic direction of the navigation vehicle, is
D converter (synchro-digital converter) 10
4, converts it into a digital signal φ _F , and then inputs it to the comparison calculation unit 110 in the calculation unit 105. The output of the drift compensation calculation section 106 is sent to the integral calculation section 108 via the coefficient calculation section 107.
After being integrated and converted into an azimuth signal φ, the signal is input to a display 112 through a decoder 111, thereby displaying the azimuth of the vehicle.

Furthermore, the output φ of the integral accumulator 108 is input to the comparison calculation unit 110, and is compared with the geomagnetic direction φ _F from the flux valve 103. The comparison output of the comparison calculation unit 110 is transferred to the coefficient calculation unit 10.
9 to the integral calculation unit 108, and based on this feedback, the residual error included in the output direction _φv of the gyro 101 is corrected. Therefore, the output φ of the integral calculation section 108 always serves as a signal indicating the correct heading of the moving object, so the display 112 always displays the correct heading of the moving object.

FIG. 4 is a functional explanatory diagram of the calculation unit 105.
In the figure, the same symbols as in FIG. 3, such as 106 and 107, indicate the same elements. In addition, in FIG. 4, K ₁ and K ₂ are the gains of the coefficient calculation units 107 and 109, S is the Laplace operator, and φ〓 _v is the gyro 101.
A digital signal of the turning angular velocity of the navigation object detected by
Further, each represents a digital signal corresponding to the geomagnetic direction of the navigation object detected by the _φF flux valve 103.

The digital signal φ〓 _v of the turning angular velocity of the navigation object contains stationary error components such as drift of the gyro, and this signal is directly input to the integral calculation unit 108.
Integrating at will result in a large orientation error, so
As described above, it is first necessary to remove the steady-state error component in the drift compensation calculation section 106.

Incidentally, the simplest example of the transfer function of the drift compensation calculation section 106 can be expressed as TS/TS+1, as shown in FIG. Here, T is a time constant.

However, when the navigation object to which the device is attached performs a motion with a relatively high frequency component, such as a turning motion or a zigzag motion, this transfer function has a time constant T of several hundred seconds or more. Since it is chosen to be a large value, its denominator becomes TS≫1, which cancels out the TS of its numerator, resulting in a gain of 1.
The drift compensation calculation unit 106 passes the input φ〓 _v as is. On the other hand, when the vehicle is in straight motion or at rest, the input φ〓 _v contains only low frequency components, and the numerator and denominator of the above transfer function
Although the TS term is a small value, since the constant 1 exists in the denominator, this drift compensation calculation unit 106
It has a transfer function of a small value, and has so-called high-pass characteristics. Therefore, steady error components such as gyro drift are not output from the drift compensation calculation unit 106.

If the system in FIG. 4, that is, the output φ of the calculation unit 105, is expressed using the Laplace operator S, φ=φ _F /S/K ₂ +1+K ₁ /K ₂ /S/K ₂ +1・TS/TS
+1・φ〓 _v ……(1). Here, the first term of equation (1) is the integral calculation unit 1
This shows that the output φ of 08 finally coincides with the geomagnetic direction φ _F , and its time constant (system response time constant) is given by = 1/K ₂ (2).

Further, the second term of equation (1) represents the response of the output φ of the integral calculation unit 108 to the output φ〓 _v of the gyro 101. Under various motion conditions of a normal navigation vehicle, the output φ of the calculation unit 105 needs to be approximately an integral with respect to the output φ〓 _v of the gyro 101. Therefore, the following equations 3 to (5 ) formula must be established.

TS≫1 ...(3) S≫1 ...(4) K ₁ = 1 ...(5) If the time constant is made longer, the stabilization time at the time of starting the device becomes longer, which causes problems in practicality. . on the other hand,
If the time constant is too short, there will be a problem in accuracy that it will respond more easily to fluctuations in the geomagnetic direction φ〓 _F. Therefore, in general, the time constant is 1 to
All you have to do is make your selection within 20 minutes.

In addition, in the example of FIG. 3, the flux valve 10
3, the S/D converter 104 is used because it is a three-phase output type.
When using a right-angle two-phase resolver type output as the flux valve 103, a corresponding R/D converter can be used in place of the S/D converter 104, which is exactly the same as the example shown in FIG. It is clear that the following effects can be obtained.

From the above, according to the example of the present invention shown in FIGS. 3 and 4, it is possible to achieve exactly the same function as the gyroscope shown in FIGS. 1 and 2, and at the same time, the gyroscope has a simple structure and is inexpensive. It will be appreciated that any rate gyro may be used. That is, according to the present invention, the uniaxial degree of freedom gyroscope 101
can be directly attached to the vessel, so it is possible to eliminate the torquers 10, 14, electrolyte level 8, slip ring 41, etc. shown in Fig. 2, and at the same time, since the slip ring 41 is not required, the rotation It is possible to reduce the angular momentum of the device, and together with the use of a rate gyro, it has become possible to make the entire device extremely small and lightweight.

Furthermore, by providing the drift compensation calculation unit 106, it is possible to automatically compensate for long-term fluctuations in the drift of the gyro 101 and maintain pointing accuracy for a long time. Allows the use of a gyroscope. Further, according to the above-described example of the present invention, all the components except the gyro do not have rotational movement, so that the reliability of the method and apparatus can be improved, and at the same time, further cost reduction can be realized.

In the example of the present invention shown in FIG. 3, the A/D converter 102 and the S/D converter 104 are used, and the arithmetic unit 105 is a digital arithmetic unit, but the present invention is of course not limited to this. For example, a synchronous rectification rotation is used instead of the A/D converter 102 to output positive and negative DC voltages corresponding to the output of the gyro, and the drift compensation calculation unit 1
As 06, an analog calculation circuit using an operational amplifier may be used. In this way, by using a mixture of an A/D converter that converts a DC voltage into a digital signal, and an operational amplifier, the calculation section 105 may be a hybrid calculation method. , digital calculation method, or hybrid calculation method.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram showing a conventional gyro compass, Fig. 2 is a schematic perspective view of a directional gyro unit used therein, and Fig. 3 is a block diagram of an example of the present invention. 4 are block diagrams showing the functions of the calculation section. In the figure, 101 is a uniaxial degree of freedom gyroscope, 10
2 is an A/D converter, 103 is a flux valve, 104 is an S/D converter, 105 is a calculation section, 106 is a drift compensation calculation section, 107 and 1
09 is a coefficient calculation section, 108 is an integral calculation section, 110
111 is a decoder, and 112 is a display device.

Claims (1)

[Scope of Claims] 1. An output corresponding to the direction of the navigation vehicle is obtained from a uniaxial degree-of-freedom gyro whose input axis is arranged in a direction perpendicular to the navigation vehicle, and the drift, etc. of the gyro included in the output is obtained. A drift compensation calculation section removes a steady error component caused by the steady error component, and an integral calculation section calculates the bearing of the navigation object based on the azimuth of the navigation object, which does not include the steady error component. On the other hand, the magnetic azimuth output of the navigation object from the geomagnetic azimuth detection device installed on the navigation object is compared with the calculated azimuth, and the comparison output is used to determine the azimuth by the gyro with a time constant of 1 to 20 minutes. A direction display method, characterized in that the direction is corrected in the integral calculation section, and the corrected direction is displayed as the direction of the navigation object. 2. A uniaxial degree-of-freedom gyroscope whose input axis is arranged in a direction perpendicular to the navigation object, a geomagnetic direction detection device installed on the said navigation object that detects the geomagnetic direction of the navigation object, and said gyroscope included in the output of said gyroscope. a drift compensation calculation unit that eliminates steady error components caused by drift, etc.; an integral calculation unit that calculates the heading of the navigation object by the gyro based on the output of the drift compensation calculation unit; A comparison calculation section that compares the output with the output of the geomagnetic direction detection device, and an output of the comparison calculation section is fed back to the integration calculation section, and the output of the direction calculation section is calculated from 1 to 1.
What is claimed is: 1. A gyro device comprising: a display device that performs correction with a time constant of 20 minutes and displays the corrected output of the integral calculation section as the heading of the navigation object.