JPS63150614A - Control system for gyroscope - Google Patents

Abstract

PURPOSE:To obtain an angular speed having no noise, to suppress vibrations, and to stably and accurately perform swiveling and measurement by directly measuring an angular speed for servocontrol which holds a gimbals at a constant angle of rotation. CONSTITUTION:A gyroscope 1 consists of the gimbals 12 which supports a rotating rotor 10, a detecting means 16 which detects the angle of rotation of the gimbals 12, and an actuator 14. In this constitution, the angle theta of rotation of the gimbals 12 from the detecting means 16 of the gyroscope 1, the angular speed theta of the gimbals 12 from an actuator 14b, and a current (i) from an actuator 14a are fed back to a servocontrol part 2 respectively and the actuator 14 is brought under servocontrol so as to hold the gimbals 12 at a command position. Then, the actuator 14a generates torque balancing with the generated torque of the gimbals 12 by the swiveling of a moving body, so that the gimbals 12 is held at a constant position.

Description

[Detailed description of the invention] [Table of contents] Overview Industrial field of application Conventional technology Problems to be solved by the invention Means for solving the problems (Fig. 1) Working example (a) One embodiment Explanation of the configuration (Figure 2) (b)
Explanation of the operation of one embodiment (Fig. 3) (C) Explanation of other embodiments Effects of the invention [Summary] A gimbal of an inertial gyro is supported by a spring, and an actuator rotates the gimbal in response to detection of rotation of the gimbal. In a gyroscope control method that controls the position at a constant level, the actuator is used to measure angular velocity and generate torque, and the gimbal control of the actuator is stabilized by servo-controlling the actuator based on the measured angular velocity of the actuator.

[Industrial application field]

The present invention relates to a control method for a gyroscope mounted on a moving body such as a self-propelled robot to measure the running direction (turning angular velocity) of the moving body, and in particular, the gimbal of the inertial gyro is held at a constant rotational position by an actuator. This invention relates to a gyroscope control method that measures the running direction using the current flowing through the actuator.

For example, FA (factory automation) and OA
As one type of office automation, self-propelled vehicles are used to transport goods, etc., and self-propelled vehicles with autonomous driving functions have been developed.

To realize this autonomous driving function, self-position measuring means is essential, and gyroscopes are seen as promising as this measuring means. In particular, the inertial gyro is suitable for applications such as self-propelled vehicles because it is inexpensive and can be miniaturized.
High measurement accuracy is required.

[Conventional technology]

An inertial gyro uses a gimbal to support a rotor (inertial body) that rotates at high speed, and uses the fact that the direction of the axis of rotation of the inertial body remains constant even if the moving object equipped with the gyro changes direction. This is what we do.

In such an inertial gyro, the turning angle is measured by the rotational output of the nutation axis of the gimbal, but a measurement error occurs due to the rotational friction of the two nutation axes.

In order to prevent this, the fourth
The gyroscope shown in FIG. 4 has been proposed. In other words, as shown in FIG. It is fixed with spring members 13a and 13b such as torsion bars.

In other words, the gimbal" 2 O'lh axis 13 a
.

13b is made of a spring member to prevent the first nutation shafts 13a and 13b from rotating relative to the frames 15a and 15b, thereby eliminating rotational friction of the ninth nutation shaft.

In this case, the reaction force due to the inertial force of the rotor 1o against the turning is applied to the spring member 13a via the gimbal 12.

13b to rotate the gimbal 12.

The torque T generated by the gimbal 12 at this time is assumed to be the gyro moment Mj and the turning angular velocity of the self-propelled vehicle ω.

T , = Mj・ω ・・・・・・・・・
・・・－・・・・・・・・・(1)

By fixing this nutation shaft, the spring members 13a, 13
Since b is twisted, errors occur due to nonlinear and hysteresis characteristics as spring characteristics and vibrations due to external disturbances.

14b is provided, and the actuator 1-1142l 14b is servo driven to balance the rotational torque of the gimbal 12 by the output of the sensor 16 that detects the rotation angle of the gimbal 12, thereby preventing the spring members 13a and 13b from twisting. ing.

The actuators 14a and 14b are flat DC motors composed of a mover (magnet) 140, 141 on the gimbal 12 side and a stator (coil) 142, 143 on the frame 15b side, and the generated torque T of this motor is , the torque constant of the motor is Bl, and the current flowing through the motor is i.

T=Bl-i... Song, song... (2). Servo control is performed so that the gimbal 12 does not rotate, so equations (1) and (2)
From the formula, M''・ω= Bl・i ω= i −Bl/Mj ・・・・・・・・・
. . . (3) due to the current i flowing through the motor 14.

The turning angular velocity ω of a moving body equipped with a gyro can be obtained.

Such servo control of the actuators 14a and 14b is performed at nine positions θ (rotation angle) shown in the block diagram of FIG. 4(B).
, angular velocity δ, and lightning current feedback control.

In FIG. 4(B), L is the inductance of the actuator 14, and R is the resistance of the actuator 14.

J is the inertia of the movable part, D is the viscous damping coefficient, is the spring constant of the spring members 13a and 13b, F- is the angle command value,
Ks, K2-Ks are a current feedback gain, a speed feedback gain, and a rotation angle feedback gain, respectively, 6Lks is an open loop gain of the power amplifier, and S is a Lagrass operator.

Also, in FIG. 9, the portion indicated by TF is the spring member 13a,
The transmission characteristic of the actuator 14 supported by the actuator 13b is the rotation angle θ obtained from the detection output of the sensor 16, and the angular velocity δ obtained from the differential value of the output of the sensor 16.

[Problem that the invention seeks to solve]

However, such gyroscopes tend to operate in a high frequency range due to the influence of vibrations from self-propelled vehicles, etc., and accurate speed feedback is required to suppress this. When differentiated, noise is easily multiplied by one rotation angle, making it difficult to obtain accurate angular velocity.
There was a problem in that it was impossible to suppress vibrations.

Furthermore, if a low-pass filter or the like is installed to reduce noise and the gain in the high frequency range is reduced, the servo characteristics will not be stable due to rotation by one phase, making it difficult to measure turning with high precision.

An object of the present invention is to stably servo control the gimbal of a gyroscope and provide a gyroscope control method capable of measuring rotation with high precision. [Means for solving the problems] FIG. FIG. 2 is a diagram explaining the principle of the present invention.

In the figure, the same parts as those shown in FIG. The actuator 14a is servo-controlled based on the measured angular velocity dK.

In the present invention, a plurality of actuators 14a.

One of the 14b is used for gimbal 120 angular velocity measurement.
The other part 14a is used for generating rotation angle control torque.

[For production]

In the present invention, the angular velocity necessary for servo control to maintain and control the gimbal 12 at a constant angle is obtained using one of the actuators provided around the rotation axis of the gimbal 12.

That is, since the angular velocity is not obtained by differentiating the rotation angle detected by the detection means 16, the angular velocity is not affected by noise that tends to occur in a high frequency range, and stable servo control can be performed. Also, since a part of the actuator is used, the angular velocity of the gimbal can be accurately detected.

Highly accurate turning measurement becomes possible.

〔Example〕

(a) Description of the configuration of one embodiment FIG. 2 is a block diagram of an embodiment of the present invention.

In the figure, the same parts as those shown in Figures 1 and 4 are indicated by the same symbols, and 130 and 131 are radial (cruciform) springs that support the nutation shafts 13a and 13b, respectively. 16a is a strain gauge, and 2 nutation shafts 13b
The amount of deformation of the radial spring 13 (i.e., the rotation angle of the gimbal 12) due to the rotational force (torque) of the gimbal 12
This is to detect.

20 is a complete integration section, and 2 is a processor (not shown) (CP
The difference (θ-
卜) is completely integrated by operational amplifier OP3 and capacitor C and output.

21 is a rotation angle feedback section, which is connected to the resistance R from the strain gauge taa.
The operational amplifier OP4 amplifies the rotation angle θ given through the gyro. 22 is an angular velocity feedback section, and one of the actuators 14b of the gyro is used as a generator, and the induced voltage in the coil 143 of the gyro is set as the angular velocity d. , an operational amplifier OPs which adds the angular velocity δ given through the resistor R4 and the output of the two-rotation angle feedback section 2) and outputs the result, 23 is a power amplifier section, and complete integration of the positional deviation of the complete integration section 20. , the angular velocity of the angular velocity feedback section 22, and the current i of the other actuator 14a (for torque generation) are combined via the resistor R7, and the other 14a of the actuator 14 is
The coil 142 is driven by a current IC, and includes an operational amplifier oP1 as a preamplifier, and a pair of drive transistors Tr1. Tr2, and a capacitor C1 provided between the amplifier OPI and the output terminal of the transistor 'rr11 Tr2. Furthermore, R
8 is a current detection resistor of the actuator.

In this example, in gyroscope 1.

Cross springs 130 and 131 are used as spring members to support the nutation shafts 13a and 13b, and the rotation angle of the gimbal 120 is detected by the strain gauge 16a provided on the cross spring 131, so that the nine rotation angles can be detected with high precision. I have to.

In addition, a pair of actuators 14a and 14b are provided at the rotation of the nutation shaft 13b, which is a rotating shaft, and the magnet 140° 141 is a fixed part, and the coils 142 and 143 are movable parts.The actuator 14a is used for torque generation, and the actuator 14b is used for angular velocity. It is used for detection.

In the control circuit 2, the current i and the angular velocity δ are negatively fed back.

The rotation angle θ is fed back positively, and furthermore, the complete integral value of the positional deviation (p−θ) is fed back positively.

(b) Description of operation of one embodiment FIG. 3 is an explanatory diagram of the configuration shown in FIG.

In the embodiment shown in FIG. 2, the strain gauge 1 of the gyroscope
The rotation angle θ of the gimbal 12 from the actuator 1
4b to the gimbal 120 angular velocity δ, the actuator 1
The stain flow i from the coil 142 of 4a is fed back to the servo control section 2, and the actuator 14a is servo-controlled to maintain the gimbal 12 at the commanded position.

That is, in contrast to the torque generated by the gimbal 12 due to the rotation of the moving body 1, a torque D6 is generated from the actuator 14a, and the gimbal 12 is held at a constant position.

At this time, since the angular velocity d is directly obtained from the other actuator 14b, stable servo control is possible without noise even when operating in a high frequency range.

Further, the servo system in FIG. 2 is shown in a block diagram in FIG. 3. In this block diagram, the transfer function from the angle command value R(8) to the rotation angle θ(S) is as follows.

The transfer characteristic when the actuator 14a is connected to the power amplifier at this time is in the range shown by PT in Figure 3, and the transfer function regarding the current output from the input voltage Vp to the power amplifier in this range is as follows. .

That is, in a system with a one-hour delay, when the rotational angular velocity of the gimbal 12 is obtained from the current value of the actuator 14b, a time delay occurs in the current value from the actual rotational angle.

This means that the inductance L of the actuator 14a
, shows that the back electromotive force of resistor R9 becomes a time delay element,
9, which cause measurement errors, and it is necessary to measure these and set the gain, etc.

To prevent this, if the gain of the power amplifier is set to 5 as large as possible (for example, 100 dB), (5
)ceremony.

It can be approximated as

That is, the PT portion in FIG. 3 is expressed as a simple proportional gain of 1/kl, and the electrical characteristics (L, R, Bl) of the actuator, which are delay elements, can be removed from the system.

This can be realized by making the power amplifier section a completely integral type, as shown by block 23 in FIG.

That is, the current i can be controlled without being influenced by the electrical characteristics of the actuator. However, it is assumed that the power supply voltage of the power amplifier is sufficiently higher than the back electromotive force of the actuator.

The band ωP of the power amplifier at this time is 'l ia k
t.

Determined by the input resistance value R7 of the power amplifier and capacitor C1, 1゛ ・・・・・・・・・・・・・・・
...(7) R6φC1.

For example, 4=1/R6・C1=100 dB,
If k, = l, then 1 (1) P: 10' rad/
s (=15.9KHz), which is because the response of the actual gyroscope is about 100Hz.
The approximation of equation (6) does not produce any errors in practice.O Also, when equation (5) is approximated to equation (6), the transfer function of equation (4) is:

becomes.

Therefore, while equation (4) includes a quartic term of S, (8)
Since the formula is up to the third-order term of S, the time delay is reduced.0 This gain, to determine 4, includes an integral element in the feedback system, and the gain at high frequencies is also large, resulting in oscillation of the system. It is necessary to obtain a stable response due to the possibility of
A typical example of this is the Butterworth type response.

To get this.

The cubic term of S.

S02 Next term.

1 to 111D2 -(□-+ka)=~ ・・・・・・・・・
...... Cl0k4Bl ω. 2 The first-order term of S.

1 kt-K 2 ・・・・・・・・・
. . . 1 to 1 may be set so as to satisfy the relationship υki (R7- to □)-1.

Here, ωC is the band of the desired Butterworth response.

Next, by completely integrating the difference between the angle command value meter and the rotation angle θ and providing positive feedback, steady-state deviation is eliminated and accurate position maintenance is possible.

At this time, by positive feedback of one rotation angle θ.

Even if we provide the above-mentioned integral element and set the gain as a dog.

Prevent spring resonance.

In other words, when a gyroscope is installed in a self-propelled vehicle,
Unlike flying vehicles, there are many disturbance vibrations.

For this reason, the spring member of the gyroscope may vibrate, and the reaction force of the spring is also negatively fed back as a reaction force proportional to the rotation angle in the servo control system, so when the spring resonates, a vibration suppression signal cannot be generated. However, it becomes unstable near the resonance point.

For this reason, the gimbal 120 rotation angle is given positive feedback.

It has the effect of canceling out the spring reaction force given as negative feedback for control purposes.

In this way, the actuator suppresses torque with frequency components that cause spring resonance.
Spring resonance can be prevented.

In equations (4) and (8), the spring constant K is canceled by the angle feedback gain of 1 in the primary term of S.

Resonance is suppressed.

Therefore, since the servo system does not resonate with disturbances and has no steady-state deviation, it is possible to perform highly accurate turning measurements.

In the embodiment of FIG. 2, the feedback gain is 4, kl
I.

k, , kl are as follows.

k4:1/R1・C k, = R3/R2, : R5/R4 kl == R8 (C) Explanation of other embodiments In the above embodiment, the gyroscope shown in Fig. 2 was explained. , the spring member and the actuator may be constructed from other known components, and the servo system may also be constructed from other known components such as the one shown in FIG.

Although the present invention has been described above using examples, the present invention can be modified in various ways according to the gist of the present invention.

These are not excluded from the present invention.

〔Effect of the invention〕

As explained above, according to the present invention, the angular velocity for servo control that maintains the gimbal at a constant rotation angle can be directly measured and obtained in the inertial gile.
It is possible to obtain noise-free angular velocity, suppress vibrations,
This has the effect that rotation measurement in a high frequency range can be performed stably and accurately.

[Brief explanation of the drawing]

FIG. 1 is a diagram explaining the principle of the present invention. FIG. 2 is a configuration diagram of an embodiment of the present invention. FIG. 3 is a detailed explanatory diagram of the present invention. FIG. 4 is an explanatory diagram of the prior art. In the figure, 1... gyroscope. 2... Servo control section. 10...Rotor. 12...Gimbal. 13a, 13b--Spring members. 14...actuator. 16...Detection means.

Claims (1)

[Claims] A gimbal (12) supporting a rotating rotor (10) is supported by spring members (13a, 13b), and a detection means (16) for detecting the rotation angle of the gimbal (12) is provided.
) and a plurality of actuators (14) arranged around the rotation axis of the gimbal (12), at least one of the plurality of actuators (14)
4b) is used for measuring angular velocity, and the other (14a) is used for generating rotation angle control torque, and the actuator (14) is used based on the detected rotation angle of the detection means (16) and the measured angular velocity of the actuator (14).
), the servo control unit (2) drives the actuator (14) to control the gimbal (12) at a constant angle. control method.