JPS63128224A - Controlling method for gyroscope - Google Patents

Abstract

PURPOSE:To measure an azimuth with high accuracy by using a complete integral type power amplifier for inputting a feedback signal of current and position. CONSTITUTION:A power amplifier 23 drives a motor coil 14c by a current, by synthesizing a complete integral quantity of a difference between an angle command value gamma and a rotational angle theta by a complete integral part 20, an angular velocity theta' of an angular velocity feedback part 22, a rotational angle theta, and a current (i) of a plate motor. The amplifier 23 is provided with an operational amplifier OP1, a pair of transistors TR1, TR2, a capacitor C1 and an input resistance R7, therefore, a transmission characteristic of the amplifier OP1 uses a complete integral type, and to an input part of the amplifier OP1, the rotational angle theta, the angular velocity theta' and the current (i), and the complete integral value of a difference between the angle command value gammaand the rotational angle theta are applied with positive feedback, a negative feedback, and positive feedback, respectively. In such a way, by forming a transfer characteristic of the power amplifier 23 for driving an actuator, as a complete integral type, a measuring error by an electric characteristic of the actuator is prevented, and an azimuth can be measured with high accuracy without causing a delay.

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 Example Explanation (Figures 2 and 3) (b)
Description of other embodiments (Fig. 4) Effects of the invention [Summary] A gyroscope control method in which the gimbal of an inertial gyro is supported by a spring, and an actuator controls the rotational position of the gimbal at a constant level in response to detection of rotation of the gimbal. By making the transfer characteristics of the power amplifier that drives the actuator completely integral, measurement errors due to the electrical characteristics of the actuator are prevented and feedback constants can be easily set.

[Industrial application field]

The present invention relates to a control method for a gyroscope mounted on a moving object such as a self-propelled robot to detect the running direction (turning angular velocity) of the moving object, and in particular to a method for holding the gimbal of an inertial gyro at a constant rotational position by an actuator. This invention relates to a gyroscope control method for detecting running direction.

For example, FA (factory automation) and OA
As part of office automation, self-propelled vehicles are used to transport goods, etc., and it is desired that these self-propelled vehicles have an autonomous driving function.

To realize this autonomous driving function, self-position measuring means is essential, and gyroscopes used in aircraft etc. are promising as this measuring means. It is suitable for application to such moving bodies. An inertial gyro uses a gimbal to support a rotor (inertial body) that rotates at high speed, and takes advantage of 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. direction detection.

In such gyroscopes, improvement in measurement accuracy is required.

[Conventional technology]

As something that can improve the measurement accuracy of gyroscopes,
The one shown in Fig. 5 is published in Japanese Patent Application Laid-Open No. 60-253912 (
This method has been proposed in Japanese Patent Application No. 59-111796).

In this proposed gyroscope, a gimbal 12 supporting a rotor 10 as an inert gyro via a spin shaft 10) is fixed to frames 15a and 15b of a self-propelled vehicle with spring members 13a and 13b such as torsion bars. It is something.

In this proposed gyroscope, a general inertial gyro has a nutation axis 13a of a gimbal 12.

13b is supported for two rotations on the frames 15a, 15b, and the turning angle is measured by the rotational output, whereas the second nutation shaft 13a is constructed of a spring member such as a torsion bar.

13b is prevented from rotating relative to the frames 15a and 15b, thereby eliminating rotational friction of the nutation shaft that causes measurement errors.

In this case, the reaction force due to the inertial force of the rotor 10 against turning is transmitted through the gimbal 12 to the torsion bars 13a, 13b.
The screw shear gimbal 12 rotates at 0. The torque T generated by the gimbal 12 at this time is, assuming that the gyro moment is Mj and the turning angular velocity of the self-propelled vehicle is ω(δ).

T=Mj・ω ・・・・・・・・・・・・
......(1).

Further, a planar motor 14 is provided, which includes magnets 14a and 14b at the bottom of the gimbal 12, and coils 14C and 14d on the frame 15b, and the output of the sensor 16 that detects the rotation angle of the gimbal 12 is used to drive the planar motor 14. , and combine the rotational torque of the gimbal 120 and the rotational torque of the flat plate motor 14.

The torsion bars iaa and tab are prevented from twisting to prevent errors due to the nonlinear and hysteresis characteristics of the torsion bars as springs and errors due to vibrations caused by external disturbances, thereby increasing precision. The generated torque T is calculated as follows, where the torque constant of the flat plate motor 14 is B/, and the current flowing through the flat plate motor 14 is i, 'T=Bl*i...
(2) Because the flat plate motor 14 is servo-controlled so that the shear gimbal 12 does not rotate.

Mj・ω=BIIIi ω=i−Bl/Mj ・・・・・・・・・・・・・・・
...(3), depending on the current l flowing through the flat plate motor 14.

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

In the conventional proposal, servo control at this time was carried out as shown in the block diagram of FIG. 5).

In FIG. 5(B), L is the inductance of the flat plate motor 14, R is the resistance of the flat plate motor 14, J is the inertia of the movable part, D is the viscous damping coefficient, and the spring member 13a,
13b is the spring constant, θ is the rotation angle, H is the angle command value,
K1. 2. 3 is the current feedback gain, speed feedback gain, and rotation angle feedback gain, respectively, fi, and! 1 is the open loop gain of the power amplifier.

S is a Laplace operator.

In the figure, the part indicated by TF is the transmission characteristic of the flat plate motor 14 supported by the spring 13b, and the gyroscope 1
In addition to the mechanical properties (inertia J, viscous damping coefficient, torque constant Bl, spring constant K of the support spring), the electrical properties of the flat plate motor 14 (inductance L, resistance R1, back electromotive force constant, etc.) are included. It was a system that was

[Problem that the invention seeks to solve]

In such a gyroscope, a flat plate motor 1
In order to obtain the rotational angular velocity (or rotational torque) of the gimbal 12 from the current value i of 4°, the current value and rotational angular velocity will correspond accurately if there is no 9-hour delay.

However, there is a problem in that the inductance L of the flat plate motor 14 and the counter electromotive force of the resistor R2 are time delay elements with respect to the detected rotation angle θ, and cause measurement errors.

Also, when setting the feedback gain to 1, the flat plate motor 1
Accurately measure the electrical characteristics of 4.

Mechanical properties had to be taken into consideration when making the decision, which caused problems in adjustment during mass production.

Furthermore, it is necessary to take these into account when converting the torque from the current value, which also creates a problem that the conversion process becomes complicated.

SUMMARY OF THE INVENTION An object of the present invention is to provide a gyroscope control method that is highly accurate and easy to work with, in which the electrical characteristics of an actuator do not affect direction measurement.

[Means for solving problems]

FIG. 1 is a diagram explaining the principle of the present invention.

In Fig. 1 (5), the same components as those shown in Fig. 5 (B) are indicated by the same symbols. ks/8 indicates the transfer characteristic of a single fully integrated power amplifier. There is.

Note that, compared to FIG. 5(b), the rotation angle θ is fed back positively with respect to the input of the power amplifier (23), and the integral value of the difference between the angle command value and the rotation angle θ is fed back positively. .

This is not essential to the principles of the invention.

That is, in the present invention, the power amplifier to which at least current and position feedback signals are input is of a completely integral type.

[For production]

The transfer characteristic when a flat plate motor is connected to the power amplifier falls within the range shown by PT in FIG. 1 (5).

If the transfer characteristic regarding the current output is determined from the input voltage Vp to the power amplifier in this range, it will be as follows.0 Therefore, it becomes a time-delayed system.

Here, if the gain of the power amplifier is set to 6 as large as possible (for example, 100 dB), then equation (4) is obtained.

It can be approximated as

This means that to the extent that the approximation from equation (4) to equation (5) holds true, the system in Figure 1 is equivalent to the system in Figure 1 (B), and Figure 1 (5) is equivalent to the system in Figure 1 (B). The PT part of is 1. The electrical characteristics (L, R, Bl) of the actuator, which are delay elements, can be removed from the system.

Therefore, the current i can be controlled without being affected by the electrical characteristics of the actuator. However, the power supply voltage of the power amplifier should be sufficiently higher than the back electromotive force of the flat plate motor.

The band ωP of the power amplifier at this time is 1. It is determined by the power amplifier's input resistance value R6 (described later) and the power amplifier's feedback capacitor capacitance C1.

becomes.

For example, k,,=l/R6・CI=100dB,
If k□=1, ωP=l □! l rad/
S (=15.9KHz),! : Naru.

This is because the actual response of the gyroscope is about 100 Hz, so the approximation of equation (5) does not produce any errors in practice.

〔Example〕

(Ex) Description of one embodiment In the block diagram of the servo control system shown in FIG. 1(5), the transfer function from the angle command value R(S) to the rotation angle θ(S) is as follows.

On the other hand, the similar transfer function in FIG. 1(B) in which equation (4) is approximated to equation (5) is:

becomes.

Therefore, while equation (7) includes a quartic term of S, (8)
Since the formula includes up to the third-order term of 8, the 9-hour delay is reduced.

In determining the gains kl and k4, it is necessary to obtain a stable response because the feedback system includes an integral element, the gain is large at high frequencies, and there is a possibility of the system starting to slope. A typical example of this is the Butterworth type response.

To get this.

cubic term of S Quadratic term of S linear term of S It is sufficient to set 4 to 4 so that the following relationship is satisfied.

Here, ωC is the desired Butterworth response band 0. For example, if 1 (l=1) is set, each feedback gain is determined as follows.

In this way, in order to set each feedback gain kl, k4, if the gain of the power amplifier is set to 6, which is large enough.

It is sufficient to measure the four mechanical parameters D, Bl, K, and J.

On the other hand, in the non-approximate system shown in FIG. 1, it is necessary to measure the inductance of the flat plate motor 14 and the resistance R in order to determine the feedback gain.

This means that the feedback gain can be set without considering the electrical characteristics of the flat plate motor, making gain setting extremely easy.
Become.

Furthermore, by making the power amplifier a completely integral type, the time delay element due to the electrical characteristics of the motor can be omitted as shown in FIG. 1 (CB), so that measurement accuracy can be improved.

Furthermore, since there is no need to take electrical characteristics into account when determining the rotational torque from the current i, torque conversion becomes easy.

This embodiment differs from the position servo system of the gyroscope disclosed in Japanese Patent Application Laid-open No. 60-253912 in that firstly, the rotation angle θ is fed back positively, and secondly, the angle command value Y The difference is that the difference between the rotation angle θ and the rotation angle θ is completely integrated and fed back positively.

The reason for this is that when a gyroscope is mounted on a self-propelled vehicle, there are many disturbance vibrations, unlike when on a flying vehicle. Therefore, it is possible that the spring member of the gyroscope vibrates, 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 if the spring resonates, a vibration suppression signal cannot be generated. , becomes unstable near the resonance point.

In order to prevent this, the rotation angle signal of the gimbal 12 is fed back positively to have the effect of canceling out the reaction force of the spring given as a negative feedback signal for control purposes. As a result, torque with a frequency component that causes resonance in the spring is applied to the flat plate motor 1.
4, the resonance of the spring can be prevented.

In equation (8), in the first-order term of S, the repulsion constant K is canceled out by the angular feedback gain of 3, thereby suppressing resonance.

Next, if a steady deviation occurs, highly accurate measurement is impossible, so feedback of the integral amount of the difference between the angle command value and the rotation angle cancels the steady deviation and enables highly accurate measurement.

Furthermore, it can be seen that in the second-order term of S in equation (8), the viscous damping coefficient can be controlled by adding 2 to the feedback gain of the angular velocity.

Furthermore, since the apparent inertia is given by J/L, this value is used as the feedback gain of the difference between the angle command value and the rotation angle by 4.
It can also be seen that it can be controlled by

In this way, the turning angular velocity of the moving object can be accurately measured using the current i without a two-hour delay, and the feedback gain of the servo system can be easily set, and the torque etc. can be easily converted from the current i.

Furthermore, since the servo system does not resonate with disturbances and has no steady-state deviation, it is possible to perform even more accurate measurements. FIG. 2 is a diagram showing the configuration of an embodiment of the gyroscope of the present invention.

In the figure, the same parts as those shown in Fig. 5 (5) are indicated by the same symbols, and 130 and 131 respectively support the nutation shafts 13a and 13b with radial (cross) springs. 16a is a strain gauge and 99 nutation axis 13b
The amount of deformation of the radial spring 131 due to the rotational force (torque) of the gimbal 12 (i.e., the rotation angle of the gimbal 12)
140 is a movable part of the flat plate motor 14 fixed to the nutation shaft 13b and provided with coils 14C and 14d; 141 is a fixed part of the flat plate motor 14 provided with reeds and magnets. This is what is being done.

In this gyroscope. The difference from the one in FIG. 5 (5) is that 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 a strain gauge 16a provided on the cross spring 131. It is designed so that two rotation angles can be detected with high precision.

In addition, a coil 14C214d is attached to the movable part 140 of the flat plate motor.
The fixed part 141 is provided with magnets 14a and 14b.

FIG. 3 is a block diagram of an embodiment of a gyroscope control circuit according to the present invention.

In the figure, 2 indicates the entire control circuit, 20 is a complete integration section, the control section consists of a processor (CPU), and the resistor R1.
and the angle command value r given via.

Rotation angle θ given from strain gauge 16a via resistor R1
21 is a rotation angle feedback section, and an operational amplifier OP4 amplifies the rotation angle θ given from the strain gauge 16a via the resistor R2. 22 is an angular velocity feedback section, in which the induced voltage obtained by using one coil 14d of the flat plate motor 14 as a generator is set as the angular velocity δ, and the operational amplifier OP
3 amplifies the angular velocity a given through the resistor R4.

This is added to the output of the rotation angle feedback section 21 and output.

Reference numeral 23 indicates a power amplifier section, a complete accumulation amount of a complete integration section 20, and an angular velocity of 9 rotation angles of an angular velocity feedback section 22.

By combining the current i of the flat plate motor 14C, the flat plate motor 14
An operating amplifier OPI, which drives the other coil 14C with current, serves as a pre-amplifier, a pair of transistors Tr l and Tr 2, and an amplifier OP.
It has a capacitor C1 provided between I and the output of the transistor 'l'r l and Tr 2, and an input resistor R7.

Therefore, the transfer characteristic of the power amplifier is a completely integral type, and the angle value is fed back positively to the input section of the operational amplifier OPI.
The angular velocity value and the current value are fed back negative, and the complete integral value of the difference between the angle command value and the angle value is fed positive feedback.

In this embodiment, the complete integration unit 20 obtains the complete integration amount of the difference between the angle command value Y and the rotation angle θ, and the feedback gain of 4 is
1/R1@C. Further, in the rotation angle feedback section 21, the rotation angle θ is multiplied by a feedback gain of 3 (= R3/R2'), and in the angular velocity feedback section 22, the angular velocity δ is multiplied by a feedback gain of (
=R5/R4). Therefore.

The integral amount is positive feedback, one rotation angle is positive feedback, and the angular velocity is negative feedback.

Further, when the current feedback gain kx=Rs, the current becomes a negative feedback.

Here, in order to obtain the angular velocity, the coil 1 of the flat plate motor 14
4d is used because the change in the output of the strain gauge 16H is analog, small, and has noise, so in order to obtain the angular velocity, the differential value of the rotation angle detected by the strain gauge 16H is not taken. .

One coil 14d of the flat plate motor 14 is used as a generator to obtain the angular velocity by an induced voltage.

In this way, the inertial gyro can measure the angular velocity of a moving object with high accuracy and over a wide range while keeping the gimbal 12 at a constant angle.Also, in the case where the power amplifier is not a completely integrating type.

It is necessary to use an operational amplifier to determine the back electromotive force by measuring the potential difference between the terminals of the flat plate motor 14, which makes the configuration complicated, but if it is a completely integral type, only a capacitor is required.

(b) Description of other embodiments FIG. 4 is an explanatory diagram of another embodiment of the present invention.

In the figure, 1a and 1b are gyroscopes,
The ones shown in the figure, 2a and 2b are control circuits respectively, and the one shown in FIG. 3, 30 is a differential amplifier, and the control circuit 2a
, 2b, and 31 is an A/D (analog/digital) converter that converts the difference between the differential amplifiers 30 into digital values.

When the gyroscope 1 is mounted on a moving object (mobile object), especially in a moving object such as a running robot.

In addition to the rotating motion of the moving body, disturbances such as vibrations accompanying the motion are applied to the gimbal as rotational force.

Since this disturbance causes an error in detecting the turning angle of the moving body, in this embodiment, the rotors of the gyroscopes 1a and 1b are rotated in opposite directions, and each gyroscope 1
The current t1 of the flat plate motors a and 1b. By taking the difference in i2, disturbance components are removed and the turning angular velocity is detected with high accuracy.

In the above embodiment, the gyroscope shown in FIG. 2 is used, but the spring member and actuator may be constructed of other known components, and the control circuit is not limited to that shown in FIG. 3. .

Although the present invention has been described above with reference to embodiments, the present invention can be modified in various ways according to the spirit of the present invention.

These are not excluded from the present invention.

〔Effect of the invention〕

As explained above, according to the present invention, in a gyroscope that uses an actuator to control and hold the gimbal at a constant angle, the electrical characteristics of the actuator do not affect direction measurement, so highly accurate direction measurement without delay is possible. In addition, the number of measurements of characteristics for setting the feedback gain of the actuator's servo control system is reduced, making it easy to set, and contributing to cost reduction. In addition, the turning angle, torque, etc. can be easily determined from the current output from the gyroscope.

[Brief explanation of the drawing]

FIG. 1 is a diagram explaining the principle of the present invention. FIG. 2 is a configuration diagram of a gyroscope according to an embodiment of the present invention. FIG. 3 is a configuration diagram of a control circuit according to an embodiment of the present invention. FIG. 4 is an explanatory diagram of another embodiment of the present invention. FIG. 5 is an explanatory diagram of the prior art. In the figure, 1... gyroscope. 2...Control circuit. 10...Rotor. 12...Gimbal. 13a, 13b++7 (ne members. 14...actuator. 23...Power amplifier section.

Claims (1)

[Claims] A gimbal (12) supporting a rotating rotor (10) is supported by spring members (13a, 13b), and detection means (16,
A gyroscope in which an actuator (14) controls the rotational position of the gimbal (12) at a constant level according to the output of the gyroscope (16a), characterized in that the transfer characteristic of the power amplifier that drives the actuator (14) is completely integral type. Gyroscope control method.