JPH05215554A - Gyro compass - Google Patents

Abstract

PURPOSE:To obtain a gyro compass having high accuracy and high reliability and including a less expensive azimuth servo and azimuth angle transmitting system. CONSTITUTION:A gyro compass has an azimuth deviation detector 8 which detects a deviation angle between a gyro case 1 and its support devices 3, 10, 13 around a vertical axis line, a step motor 50 for rotating the support devices around the vertical axis with respect to a disk 16, and an azimuth controller 100 for controlling the step motor 50. The azimuth controller 100 includes an azimuth controlling part 110 for inputting a deviation signal 8A from the azimuth deviation detector 8, a motor controlling part 120 including a voltage-frequency converter and a pulse direction discriminator, a step motor driver 130 and an azimuth angle accumulator 140 while a pulse rate suppressing means is provided between the azimuth controlling part 110 and the voltage- frequency converter.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gyro compass suitable for use in, for example, a high speed vessel.

[0002]

2. Description of the Related Art Conventionally, a gyro compass is often used for measuring the course of a ship. FIG. 9 shows a gyro compass according to a conventional example disclosed in Japanese Patent No. 428317 related to the same applicant as the present applicant.

The gyro compass A has a gyro case 1 containing a gyro rotor, and the gyro rotor is rotated at a constant rotational speed by an induction motor. The gyro rotor or gyro has a horizontal spin axis, and its rotation vector is southward (clockwise when viewed from the north side). The gyro case 1 has a pair of vertical shafts 2 and 2 ′ that project vertically,
2'is a ball bearing 4 attached to a corresponding position of a vertical ring 3 arranged outside the gyro case 1,
It is fitted to the inner ring of 4 '. The upper vertical shaft 2 is attached to a vertical suspension line mounting base 5'via a vertical suspension line 5, and the vertical suspension line 5'is supported on the vertical ring 3.

The entire weight of the gyro case 1 is carried by the vertical suspension line 5 or the vertical suspension line mounting base 5 ', and
Thrust load is not applied to the ball bearings 4 and 4 ′ of the vertical shafts 2 and 2 ′, and the friction torque of the ball bearings 4 and 4 ′ can be reduced. A pair of liquid stabilizers 6 and 6 ′ are attached to both east and west sides of the vertical ring 3, and a damping weight 7 is attached to the west side of the gyro case 1. The liquid stabilizers 6 and 6 ′ function as a finger north device for moving the gyro case 1 in the finger north direction, and the damping weight 7 functions as a vibration damping device for damping the finger north motion in the gyro case 1.

The vertical ring 3 has a pair of horizontal axes 9, 9 ',
The horizontal axes 9 and 9'are perpendicular to both the vertical axes 2 and 2'and the gyro spin axis and project outward from the east-west position. The ends of the horizontal axes 9 and 9'are vertical rings. 3 are respectively fitted to the inner rings of ball bearings 11 and 11 ′ attached to corresponding positions of the horizontal ring 10 arranged on the outer side of 3. The horizontal ring 10 is further provided with horizontal axes 9 and 9'in the horizontal plane.
Has a pair of gimbal axes 12, 12 'orthogonal to the. Each of the gimbal shafts 12 and 12 ′ is fitted to the inner ring of a pair of gimbal shaft ball bearings 14 and 14 ′ attached to a follow-up ring 13 arranged outside the horizontal ring 10.

The follow-up ring 13 has a pair of follow-up shafts 15 and 15 'which project upward and downward.
5'is fitted to the inner ring of the follower shaft ball bearings 17 and 17 'attached to the corresponding positions of the board 16.
A vertical ring 3, a horizontal ring 10 and a follow-up ring 13 and three axes 2, 2 ', 9, 9', 12, 1 for rotatably connecting them to each other.
2'constitutes a supporting device for supporting the gyro case 1 with three axes.

A compass card 18 is attached to the shaft end of the upper follower shaft 15, and the compass card 1
The azimuth angle of the bow is read by 8 and the base line 18B fixed to the corresponding position on the bow side of the board 16. A bearing gear 21 is attached to the lower follower shaft 15 ',
The azimuth gear 21 is connected to the board 1 via the azimuth pinion 20.
It is connected to the rotary shaft 19A of the azimuth servomotor 19 attached to the lower part of the position 6. The azimuth gear 21 is engaged with the rotary shaft 22A of the azimuth transmitter 22 via a gear train, and the azimuth signal of the azimuth oscillator 22 is converted into an electric signal and transmitted to the outside.

The inside of the horizontal ring 10, that is, the portion including the horizontal ring 10, the vertical ring 3, the gyro case 1, etc. is usually called a sharpened portion. Such sharp parts are gimbal shafts 12 and 12 '.
A heavy physical pendulum is constructed downwardly around the horizontal axis 9 and 9 ', so that the horizontal axis 9, 9'is always kept in the horizontal plane regardless of the inclination of the hull.

A follow-up pickup 8 is attached to the east side of the gyro case 1, and the follow-up pickup 8 is a primary coil 8-1 of a differential transformer arranged in the gyro case 1 and a vertical ring facing the primary coil 8-1. And the secondary coil 8-2 of the differential transformer arranged at the position 3. If there is a difference between the orientation of the gyro case 1 and the orientation of the vertical ring 3,
The difference is detected by the follow-up pickups 8 provided on both sides, and the azimuth difference is converted into an electric signal 8A and supplied to the external servo amplifier 23. The electric signal 8A is amplified by the servo amplifier 23 and supplied to the azimuth servomotor 19, which controls the azimuth servomotor 19.

The rotation of the azimuth servomotor 19 depends on the rotation axis 1.
The vertical ring 3 and the gyro case 1 are transmitted to the follower ring 13 via 9A, the gear train, and the azimuth gear 21, and further to the vertical ring 3 via the horizontal ring 10, the horizontal shafts 9 and 9 ', etc.
The bearing deviation between and is always kept at zero. Thus, the azimuth servo system for controlling the azimuth servo motor 19 is constructed.

By the action of the azimuth servo system, the horizontal axis 9,
9'and the spin axis of the gyro are always orthogonal to each other, and the torsion torque of the vertical suspension line 5 is not applied to the gyro case 1. That is, the gyro case 1 is completely shielded from angular movement such as rocking of the hull by the action of the three axes of the vertical shafts 2 and 2'having the servo system, the horizontal shafts 9 and 9'and the gimbal shafts 12 and 12 '. It will be done and will constitute a gyroscope.

[0012]

The gyro compass has the azimuth servomotor 21 in the azimuth servo system and the azimuth transmitter 22 in the azimuth angle transmission system as described above. The azimuth servo motor 21 is required to have wide responsiveness from a low speed range to a high speed range, a long product life, and a small size. On the other hand, the azimuth oscillator 22 has high resolution, high precision, and high accuracy. It is required to have reliability.

Azimuth servo motor 21 and azimuth transmitter 22
Is generally a high price because it is a special industrial product that requires such performance. Further, although not shown in FIG. 9, a gear train is actually provided between the azimuth gear 21, the rotation shaft 19A of the azimuth servomotor 21, and the rotation shaft 22A of the azimuth transmitter 22. The rows are also required to have high accuracy and high reliability.

Therefore, in the price of the gyro compass, the ratio of the azimuth servo system including the azimuth servo motor 21 and the azimuth angle transmission system including the azimuth oscillator 22 is large. In view of such a point, an object of the present invention is to provide a gyro compass including an azimuth servo system and an azimuth angle transmission system, which has high accuracy and high reliability and which is lower in price.

[0015]

According to the present invention, a gyro case 1 containing a gyro having a spin axis substantially horizontal, and a supporting device 3 for supporting the gyro case 1 in three axes of freedom, Between the gyro case 1 and the support device, a vibration damping device for applying a torque proportional to the inclination of the spin axis with respect to the horizontal plane to the gyro case 1 about the vertical axes 2 and 2 ′ orthogonal to the spin axis. Azimuth deviation detecting device 8 for detecting a declination angle around the vertical axis of, and a step motor 5 for rotating the supporting device with respect to the board 16 around the vertical axis.
In the gyro compass having 0 and the azimuth control device 100 that controls the step motor 8 based on the signal from the azimuth deviation detection device 8, the azimuth control device 100 inputs the deviation signal 8A from the azimuth deviation detection device 8. The azimuth controller 110, the voltage frequency converter 120-7, the pulse direction discriminator 120-8, and the step motor driver 130 are included, and the azimuth controller 110 and the voltage frequency converter 120-7 are included.
Between the pulse rate suppressing means 120-1 to 120-6
Is provided.

According to the present invention, in such a gyro compass, pulse rate suppressing means 120-1 to 120-
6 compares the previous pulse rate and the current pulse rate (120-2), and outputs the current pulse rate as it is (120-
4) If the difference is larger than the predetermined pulse rate, the predetermined pulse rate is added to or subtracted from the previous pulse rate and output (120-5).

According to the present invention, in such a gyro compass, the azimuth control device 100 includes the pulse direction discriminator 12
Cumulative calculation means 140 for accumulating output pulses from 0-8
And a reference pulse generator 60 provided between the board 16 and the supporting device, and resets the output signal from the accumulator 140 by the output pulse from the reference pulse generator 60. Output the direction output signal HEA
It is configured to output as D.

[0018]

According to the present invention, a widely used step motor 50 is used in place of the azimuth servo motor 19 and the azimuth oscillator 22, and the step motor 50 is controlled by the azimuth controller 100. It The azimuth control device 100 includes a pulse rate suppressing unit 120, and the step rate of the step motor 50 is prevented by the pulse rate suppressing unit 120.

[0019]

Embodiments Embodiments of the present invention will be described below with reference to FIGS. 1 to 8, corresponding parts in FIG. 9 are designated by the same reference numerals, and detailed description thereof will be omitted.

FIG. 1 shows a gyro compass of the present example. The gyro compass of the present example is different from the gyro compass of the conventional example shown in FIG.
A step motor 50 is provided instead of 9, and the azimuth transmitter 2
2 and the servo amplifier 23 are removed, the azimuth control device 100 is installed instead, and the zero-cross oscillator 60 is attached to the azimuth gear 21.

When the tracking pickup 8 detects that an azimuth difference has occurred between the gyro case 1 and the vertical ring 3, the azimuth difference is converted into an electric signal 8A and supplied to the azimuth control device 100. .. The direction control device 100 outputs a control signal CS to the step motor 50,
The step motor 50 is controlled based on the control signal CS. When the step motor 50 rotates, the azimuth gear 2
1 is rotated and the horizontal ring 10 and the vertical ring 3 are rotated. Thus, the azimuth of the vertical ring 3 follows the azimuth of the gyro case 1, and the azimuth difference between the two is always zero.

As shown in FIG. 2, the azimuth control device 100 has an azimuth control unit 110, a step motor control unit 120, a driver unit 130, and an azimuth angle accumulation unit 140. The electric signal 8A output from the follow-up pickup 8 is input terminal 10
The electric signal V _OUT is input to the azimuth control unit 110 via 0a and is output to the step motor control unit 120 from the azimuth control unit 110.

The step motor controller 120 outputs a pulse signal CW for rotating the vertical ring 3 in the clockwise direction as viewed from above the gyro compass or a pulse signal CCW for rotating the vertical ring 3 in the counterclockwise direction. Driver section 1
Reference numeral 30 outputs a control signal CS for controlling the step motor 50 to the step motor 50 via the output terminal 100c in response to the pulse signal CW or CCW output from the step motor controller 120. The azimuth angle accumulating unit 140 responds to the input pulse signal CW or CCW, and outputs the azimuth angle signal HE of the gyro compass via the output terminal 100d.
AD is output, whereby the azimuth angle of the gyro compass is displayed on a display (not shown).

The reset signal RS output from the zero-cross oscillator 60 is input to the azimuth angle accumulator 140 via the input terminal 100b. As will be described later, the reference signal of the azimuth signal HEAD indicating the azimuth of the support device with respect to the board 16 is given by the reset signal RS.
The azimuth control unit 110 is a control system that establishes the characteristics of the azimuth servo system of the gyro compass, and a block diagram of the azimuth servo system is shown in FIG. In FIG. 3, block 110
-1 is the follow-up pickup gain K _PV , block 11
0-2 is the control unit G _C (S), block 110-3 is the voltage pulse frequency gain K _VF , and block 110-4 is the rotation angle STE per pulse of the step motor 50.
In P and block 110-5, the reciprocal of the ratio N between the rotation angle of the step motor 50 per pulse and the rotation angle of the vertical ring 3 is shown. S represents a Laplace operator, but equivalently represents a step motor.

In the block diagram of FIG. 3, the control unit G
_C (S) corresponds to the azimuth control unit 110. When the transfer function of the tracking error with respect to the input of the gyro compass direction servo system is obtained,

[0026]

[Equation 1]

Where S is the Laplace operator and D ₁ (S)
Is a disturbance term, and α and β are respectively given by the following equation (2).

[0028]

[Equation 2]

Here, if the disturbance term D ₁ (S) is omitted, the equation of the equation 1 becomes

[0030]

[Equation 3]

It becomes Control unit G _C (S) is PI (proportional +
Assuming that it operates by (integral) control,

[0032]

[Equation 4]

Here, K _P is a proportional gain and T _I is an integration time constant. Substituting this equation of equation 4 into the equation of equation 3,

[0034]

[Equation 5]

The numerator on the right side of this equation is S ² . Therefore, when the control unit G _C (S) is operated by PI control, it is possible to ignore the steady-state error even if the input signal θ _in (S) is a step input or a ramp input. It is clear from the theorem of.

Next, let us consider the influence of a steady error on the step input of the disturbance term D ₁ (S) with the input signal θ _in (S) = 0. From the formula of Equation 1,

[0037]

[Equation 6]

The steady-state error of the disturbance term D ₁ (S) with respect to the step input is

[0039]

[Equation 7]

It becomes Therefore, the disturbance term D ₁ (S), that is, the offset voltage of the electric circuit or the like can be ignored.

Thus, by configuring the control unit G _C (S), that is, the azimuth control unit 110 to PI control as shown in the equation (4), a tracking error can be obtained even for an angular velocity motion such as turning of the gyro compass. The characteristic of the azimuth servo system that does not occur can be obtained. The step motor control unit 120 inputs the electric signal V _OUT output by the azimuth control unit 110 and outputs a pulse signal CW or CCW to the driver unit 130. The step motor 50 has its rotation shaft rotated in response to the pulse signal CW or CCW.

The step motor 50 rotates in synchronization with the pulse of the control signal CS supplied from the driver section 130,
The rotation speed is determined by the pulse speed (pps), that is, the pulse frequency, and the rotation angle is determined by the pulse number.

However, the step motor 50 has its own self-starting region with respect to the input pulse frequency, and therefore the step motor 50 becomes incapable of responding (step-out) to the input pulse signal. Sometimes.

The operating characteristics of the step motor 50 will be described with reference to FIG. FIG. 4 shows a pulse-torque characteristic curve of a conventional stepper motor, which characteristic curve shows the relationship between the frequency of the input pulse and the torque generated by the stepper motor. The characteristic of the step motor 50 has three regions divided by two curves as shown in the figure, and the self-starting region X below the self-starting limit curve A is shown.
And a through region Y sandwiched between the self-starting limit curve A and the through limit curve T and a region Z outside the through limit curve T.

In the self-starting region X, the step motor 50 can be started from a stopped state or stopped from an operating state. In the through area Y, the step motor 50
Can change from one operating state to another, but cannot start from a stopped state or stop from an operating state. When the step motor 50 is started from the stopped state or stopped from the running state in the through region Y, the step motor 50 loses step and becomes unrotatable.

For example, when the frequency of the input pulse is PF1, the step motor 50 can be started from the stopped state or stopped from the operating state because it is in the self-starting region X. However, if the frequency of the input pulse is PF
When it is 2, the stepping motor 50 is present because it is in the through area Y.
Can not be started from the stopped state, and loses control.

For example, when the tracking pickup 8 detects a large azimuth difference and the azimuth control signal device 100 outputs the control signal CS having the pulse frequency PF2 to the step motor 50, the step motor 50 is operated.
Will be out of sync.

An area Z outside the through area Y is a non-operation area. It is assumed that the torque generated by the step motor 50 is sufficiently larger than the load torque, and the consideration of the increase of the load torque generated during the acceleration / deceleration of the step motor 50 will be omitted. The step motor 50 may be a commercially available one, and a detailed description of its structure and other functions will be omitted.

The step motor control section 120 has a pulse rate suppressing means, and the pulse rate suppressing means functions so as to prevent the step motor 50 from being out of step. Next, the function of the step motor control unit 120 will be described with reference to the flowchart shown in FIG. The operation of the step motor control unit 120 is the start step 120-
0, absolute value calculation step 120-1, deviation value calculation step 120-2, deviation value determination step 120-3, replacement steps 120-4, 120-5 and 120-6, pulse frequency conversion step 120-7, direction classification. It includes step 120-8 and ending step 120-9. At the start step 120-0, the electric signal V
_OUT is input. In the absolute value calculation step 120-1, the absolute value of the electric signal V _OUT input from the azimuth control unit 110 is calculated, and the absolute value signal V _X representing the absolute value is calculated.
Are supplied to the deviation value calculation step 120-2. Furthermore,
The positive or negative polarity of the electric signal V _OUT is determined, and the polarity signal PS indicating the polarity is output to the direction classification step 120-8.

In the deviation value calculation step 120-2, the present absolute value signal V _X is compared with the previous absolute value signal V _X0 to calculate the deviation value ΔV. Deviation value determination step 120
At -3, the absolute value of the deviation value ΔV from step 120-2 is compared with the set value V _S. When the absolute value of the deviation value ΔV is smaller than or equal to the set value V _S , the process proceeds to the replacement step 120-4, and when the absolute value of the deviation value ΔV is larger than the set value V _S , the process proceeds to the replacement step 120-5. In step 120-5, the symbol Sign represents an operation of extracting the positive / negative sign of the variable in parentheses. In step 120-4, the output V _Y replaced with the current absolute value signal V _X is output as it is, and in step 120-5, the value calculated based on the previous absolute value signal V _X0 is output as the output value V _Y. To be done. The output value V _Y from the replacing step 120-4 or step 120-5 is replaced as the previous absolute value signal V _{X0 in} the replacing step 120-6.

The output value V _Y from the replacing step 120-4 and step 120-5 is further converted into a pulse frequency in the pulse frequency converting step 120-7 and the pulse frequency signal PF is output. Direction classification step 12
In 0-8, the pulse frequency signal PF from the pulse frequency conversion step 120-7 and the absolute value calculation step 120-1
Pulse signal CW or C based on the polarity signal PS from
CW is calculated. The pulse signals CW and CCW are obtained by the following logical operation formula.

[0052]

[Equation 8]

Here, the symbol ∩ represents the AND of the logical operations, and the symbol ∣ represents the inversion of the logical operations. The pulse signals CW and CCW are supplied to the step motor controller 120 in the ending step 120-9.

In the step motor control unit 120, steps 120-1 to 120-6 constitute pulse rate suppressing means, and when the frequency of the input pulse exceeds the self-starting region X and is in the through region Y by this. However, the step motor 50 can be started without step-out.
The pulse rate suppressing means will be specifically described below.

First, as the first case, the azimuth control unit 11
The electric signal V _OUT is input to the step motor control unit 120 from 0, and the electric signal V _OUT (the polarity is positive).
Is converted into a pulse signal having a frequency of PF1 by the step motor control unit 120, and the pulse signal CW or CC
Consider a case where W is generated and supplied to the step motor 50. In step 120-1, electric signal V _OUT1
The absolute value | V _OUT1 | of is calculated, but since the electric signal V _OUT1 has a positive polarity, V _X = V _OUT1 . Step 120
At −2, the deviation value ΔV is calculated, but since the previous electric signal is V _XO = 0, the deviation value ΔV = V _X. In the deviation value determination step 120-3, the set value V _S is

[0056]

[Equation 9]

If so, the determination result in step 120-3 is YES, and the process proceeds to replacement step 120-4. The set value V _S is the frequency PF1 of the self-starting region X.
It corresponds to. In step 120-4, V _Y = V _X is replaced, but V _Y = V _S is output according to the equation (9). In the pulse frequency conversion step 120-7,
The pulse frequency PF corresponding to the set value V _S is converted.
The pulse frequency is always the self-starting frequency PF1,
The pulse signal CW or CCW output from the direction classification step 120-8 is also within the self-starting area X.

Therefore, when the electric signal V _OUT1 from the azimuth control unit 110 corresponds to the pulse signal CW or CCW in the self-starting region X, the pulse signal having the frequency PF1 is supplied to the step motor 50. .. However, in the second case, the electric signal V _OUT2 from the azimuth control unit 110 is the pulse signal CW or CCW in the through region Y.
, The pulse signal having the frequency obtained as described below is supplied to the step motor 50 instead of the pulse signal having the frequency PF2. However, in this case, it is assumed that the frequency PF2 is approximately four times as large as the frequency PF1.

The electric signal V _OUT2 output from the azimuth control unit 110 has the absolute value calculation step 120-
1, the deviation value calculation step 120-2 and the deviation value determination step 120-3 are performed. Deviation value determination step 120-3
Then, the absolute value of the deviation value is larger than the set value, and | ΔV ₁ |
> V _S Therefore, the judgment result is No and the replacement step 1
Proceed to 20-5.

In the first cycle, since the previous absolute value signal is V _X0 = 0, V _{Y is used in the} replacement step 120-5.
= + V _{S is} replaced. Such output signal V _Y
Is the replacement step 120-6, the pulse frequency conversion step 120-7, and the direction classification step 1 as described above.
Proceeding to 20-8, pulse signal CW of self-starting frequency PF1
Or CCW is generated. In this way, the stepping motor 50 is started without step out by the control signal CS generated in the first cycle. In the first cycle, the replacement step 120-6 is

[0061]

[Equation 10]

Has been replaced. 2nd service
Even in an icicle, in the deviation value determination step 120-3, | Δ
V₂|> V _STherefore, proceed to replacement step 120-5.
Mu. However, in the replacement step 120-5,
V from the formula of equation 10_X0= V_SSo

[0063]

[Equation 11]

It becomes The output signal V _Y is frequency-converted in the pulse frequency conversion step 120-7. In this way, from the step 120-7 in the second cycle, from the step 120-7, the pulse signal of the frequency 2 × PF1 corresponding to the output signal of the formula 11 is obtained instead of the pulse signal of the frequency PF2 corresponding to the electric signal V _OUT2 . A pulse signal is output.

The pulse of frequency 2 × PF1 supplied to the step motor 50 is in the through area Y which exceeds the self-starting area X. However, since the step motor 50 has already been started by the pulse of the frequency PF1 supplied in the first cycle, even if the pulse of the frequency 2 × PF1 is output in the second cycle, Frequency deviation value ΔPF (= PF1) of the self-starting region X
As long as it is inside, the step motor 50 does not step out. Thus, the step motor 50 is rotated at twice the rotational speed by the frequency 2 × PF1 pulse twice the frequency PF1. By the third and subsequent cycles, similarly, the pulse frequency of the output signal from the step motor control unit 120 sequentially increases, thereby increasing the rotation speed of the step motor 50. The pulse rate suppression operation described herein will be more easily understood with reference to the graphs of FIG.

The graph of FIG. 6 shows the step motor controller 1
20 shows the relationship between the electric signal V _OUT input to the signal 20 and the frequency PF of the pulse signal CW or CCW output from the step motor control unit 120. In FIGS. 6A and 6B, the electric signal V _OUT1 corresponding to the frequency PF1 in the self-starting region X is time t.
If the input to the stepper motor controller 120 to ₁ ~t _2, shows that the pulse frequency PF1 is directly output from the motor control unit 120 at time t ₁ ~t ₂ against the step motor 50. This is the first case described above. However, it should be noted that the electrical signal V _OUT and the frequency PF1 are related by the voltage pulse frequency gain K _VF . 6C and 6D show the frequency P in the through region Y.
When the electric signal V _OUT2 corresponding to F2 is input to the step motor control unit 120 from time t _{1 to} t ₂ , the frequency PF is transmitted from the motor control unit 120 to the step motor 50.
It is shown that the pulse of 2 is not output as it is, but the pulses of the frequency smaller than the frequency PF2 are sequentially output. This is the second case.

With reference to FIG. 6D, the pulse frequency PF output in each cycle of the pulse rate suppressing operation cycle in the second case will be described. Frequency PF of the pulse, the time t ₁ ~t ₁ corresponding to the first cycle to the fourth cycle constant frequency PF2 next in ~t ₂ 'successively increases at the time t ₁ corresponding to the fifth and subsequent cycles', first Times t ₂ to t corresponding to the'cycle to the 4th 'cycle
It is decreasing gradually at ₂ '. When the pulse frequency PF changes stepwise, it corresponds to the update of the frequency PF in each cycle.

At time t ₁ , the electric signal V _OUT2 corresponding to the frequency PF2 is input, and in the first cycle, the result of the deviation value determination step 120-3 becomes NO and step 120-5.
A pulse of frequency PF1 is output via the. Even in the next second cycle, the result of the deviation value determination step 120-3 is NO, and the previous frequency PF1 is determined in step 120-5.
Since the frequency increment ΔPF (= PF1) is added to, a pulse having a frequency of 2 × PF1 is output. Similarly, in the third cycle, a pulse of frequency 3 × PF1 is output,
In the cycle, a pulse of frequency 4 × PF1 is output.

However, as described above, the frequency PF
Since it is assumed that 2 is almost four times the frequency PF1,
In the cycle, the result of the deviation value determination step 120-3 is YES. In the deviation value calculation step 120-2, the current input absolute value signal V _X (= | V _OUT2 |) is compared with the previous absolute value signal V _X0, and the deviation value ΔV ₅ (the subscript indicates the number of cycles). However, since the input absolute value signal V _X this time is a value corresponding to the pulse of the frequency PF2 and the previous absolute value signal V _X0 is a value corresponding to the frequency 4 × PF1, the deviation value is ΔV ₅ = It becomes 0. Thus, in step 120-3, the determination result is YES,
Proceed to replacement step 120-4. Thus, in the fifth cycle, the frequency PF2 corresponding to the input electric signal V _OUT2
The pulse signal of is output. This is the same as the frequency 4 × PF1 of the pulse output in the fourth cycle. Fifth
The pulse signal of the frequency PF2, which is equal to the frequency 4 × PF1, is output in the subsequent cycles.

At time t ₂ , the input electric signal is V _OUT = 0.
However, similarly, the frequency PF of the output pulse signal is decreased by the frequency variation ΔPF (= PF1) in each cycle from the 1'cycle to the 4'cycle, and then becomes the 4'cycle. It becomes 0. The frequency PF of the output pulse signal is 0 even in the 5'th and subsequent cycles.

As is apparent by comparing FIGS. 6A and 6B with FIGS. 6C and 6D, the pulse rate suppressing means functions in FIGS. 6C and 6D, and the input electric signal V _OUT =
V _{OU T2} or V _OUT = frequency PF2 or 0 corresponding to 0
The modified pulse signal is generated instead of the pulse signal CW or CCW.

Next, the configuration and function of the driver unit 130 are shown in FIG.
Will be described. The driver unit 130 uses the pulse signal CW or CC supplied from the step motor control unit 120.
The circuit is configured as a circuit for supplying a pulse train of W to the winding of the step motor 50 in a predetermined order, and includes an excitation signal generation unit 130-1 and an amplification unit 130-2. The pulse signal CW or CCW supplied from the step motor controller 120 via the input terminals 130a and 130b is shaped and distributed by the excitation signal generator 130-1. The signal ES output from the excitation signal generator 130-1 is amplified by the amplifier 130-2. The control signal CS output from the amplification unit 130-2 is supplied to the step motor 50 via the output terminal 130c.

Although not shown in FIG. 7, a power source for applying a voltage to the winding of the step motor 50 is connected to the driver section 130, and such a power source is preferably a DC stabilized power source. To be done.

The azimuth angle accumulating section 140, as shown in FIG.
A difference unit 140-1 and an accumulation unit 140-2 are included. The pulse signals CW and CCW supplied from the step motor control unit 120 are input to the difference unit 140-1 via the input terminals 140a and 140b. Therefore, the difference ΔC between the frequencies of the pulse signals CW and CCW is calculated and output by the following equation (12).

[0075]

[Equation 12]

In the accumulator 140-2, the difference ΔC is cumulatively calculated and the cumulative value is output as the azimuth angle signal HEAD. That is,

[0077]

[Equation 13]

As shown in FIG. 1, a zero-cross generator 60 for adjusting the zero point of the compass gear is provided. When the reset signal RS from the zero cross generator 60 is supplied to the accumulator 140-2, the accumulated value calculated by the accumulator 140-2 is replaced with the reference azimuth signal HEAD0.

[0079]

[Equation 14]

Here, the reference azimuth signal HEAD0 represents the reference value of the azimuth of the support device with respect to the board 16. By the reset signal RS, the operation of the equation (14) is performed, and the difference in the azimuth accumulating unit 140 and the error generated in the cumulative calculation can be eliminated.

Although the embodiments of the present invention have been described above in detail, those skilled in the art will understand that the present invention is not limited to the above-mentioned embodiments and various other configurations can be adopted without departing from the gist of the present invention. Easy to understand.

[0082]

According to the present invention, since a relatively low-priced step motor is used instead of a high-priced servo motor, it is possible to manufacture a gyro compass that is cheaper than a conventional gyro compass. There are advantages.

According to the present invention, since the step motor 50 capable of generating a large torque is used, it is not necessary to use a multistage gear train having a large reduction ratio like the conventional gyro compass, and therefore the mechanism is There is an advantage that a simpler gyro compass can be provided.

According to the present invention, the azimuth transmitter used in the conventional gyro compass is unnecessary, so that there is an advantage that the price of the gyro compass can be set at a lower price.

According to the present invention, in the gyro compass having the step motor 50, since the azimuth control device 100 is provided with the pulse rate suppressing means, there is an advantage that the step motor 50 can be controlled without step-out. ..

[Brief description of drawings]

FIG. 1 is a diagram showing an example of a gyro compass of the present invention.

FIG. 2 is a block diagram showing an example of an azimuth control device.

FIG. 3 is an explanatory diagram showing an operation of an azimuth servo system.

FIG. 4 is a diagram showing characteristics of a step motor.

FIG. 5 is a flowchart showing an operation of a step motor control section.

FIG. 6 is an explanatory diagram showing a pulse rate suppressing operation of a step motor controller.

FIG. 7 is a block diagram showing an example of a drive unit.

FIG. 8 is a block diagram showing an example of an azimuth accumulating unit.

FIG. 9 is a diagram showing an example of a conventional gyro compass.

[Explanation of symbols]

 1 Gyro Case 2, 2'Vertical Axis 3 Vertical Ring 4, 4'Ball Bearing 5 Vertical Suspension Line 5'Straight Suspension Line Attachment 6,6 'Liquid Stabilizer 7 Damping Weight 8 Follow-up Pickup 9, 9'Horizontal Axis 10 Horizontal Ring 11 , 11 'Ball bearing 12, 12' Gimbal shaft 13 Follower ring 14, 14 'Ball bearing 15, 15' Follower shaft 16 Board device 17, 17 'Ball bearing 18 Compass card 18B Baseline 19 Direction servo motor 19A Rotation axis 20 Direction pinion 21 azimuth gear 22 azimuth oscillator 23 servo amplifier 50 step motor 60 zero-cross oscillator 100 azimuth control device 110 azimuth control unit 120 step motor control unit 130 driver unit 140 azimuth angle accumulating unit

Claims (3)

[Claims] 1. A gyro case having a gyro with a spin axis substantially horizontal, a support device for supporting the gyro case with three degrees of freedom, and a torque proportional to the inclination of the spin axis with respect to a horizontal plane. A vibration damping device applied to the gyro case around a vertical axis orthogonal to the spin axis, an azimuth deviation detection device for detecting a deviation angle around a vertical axis between the gyro case and the support device, and the support In a gyro compass having a step motor that rotates the device around a vertical axis with respect to a board, and an azimuth control device that controls the step motor based on a signal from the azimuth deviation detection device, the azimuth control device, An azimuth controller for inputting a deviation signal from the azimuth deviation detecting device, a voltage frequency converter, a pulse direction discriminator, and a step motor driver are provided. See, gyrocompass, characterized in that a pulse rate suppression means between said orientation controller and the voltage frequency converter. 2. The gyrocompass according to claim 1,
The pulse rate suppressing means compares the previous pulse rate with the current pulse rate, and outputs the current pulse rate as it is when the difference is within a predetermined pulse rate, and when the difference is larger than the predetermined pulse rate. Is a gyro compass characterized in that it is configured to output by adding and subtracting the predetermined pulse rate to the previous pulse rate. 3. The gyro compass according to claim 1 or 2, wherein the azimuth control device is provided between the accumulator for accumulating output pulses from the pulse direction discriminator, the panel device, and the support device. With a reference pulse generator,
A gyro compass characterized in that the output signal from the accumulator is reset by the output pulse signal from the reference pulse generator and the output of the accumulator is output as an azimuth output signal.