JPH0886657A - Method for damping vibration by using gyro mechanism - Google Patents

Abstract

PURPOSE: To make a gyro mechanism possible to fully exhibit its capacity by making variable the gain fed back for controlling a main system which is the object to be damped by means of the gyro mechanism. CONSTITUTION: A rotor 1 is incorporated in a gimbal 3 and rotated at a fixed angular velocity against the gimbal 3. The resistance torque against the disturbance acting on a main system 2 to be damped is a gyro moment which acts on the rotor 1 and generated when the gimbal 3 is rotated by means of an actuator 5. The angular momentum, speed feedback, constant gain, and variable gain of the main system 2 are controlled. When the gain of the main system 2 is made variable as a control law, the main system 2 can be controlled without saturating the gimbal angle even when the energy to be controlled becomes larger due to the disturbance and a larger control torque can be obtained as compared with the controlling method using a constant gain in a region where the energy of the main system 2 is small. Thus a gyro mechanism can be made to fully exhibit its capacity.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is intended to prevent rolling and pitching swaying due to waves of a ship, wind swaying of a gondola or suspended monorail, and swaying of a suspended load of a crane.
The present invention relates to a vibration control method using a gyro mechanism that can be applied to a structure such as a tower or a building to prevent shaking due to wind, earthquake, or movement of a load.

[0002]

2. Description of the Related Art When a rotating object changes the direction of its axis of rotation, a gyro-moment is applied from the object to the outside world in an amount that balances this movement. As a device using this, it has been conventionally used for a vibration control device for ships, attitude control of satellites and aircraft, and the like.

First, the principle of the gyro mechanism will be described. The gyro mechanism includes a gimbal and a rotor. The rotor rotates at a constant angular velocity and is rotatably attached to the gimbal. The gimbal is rotatably attached to the main system by a gimbal shaft. Now, if disturbances (such as wind, waves, and ground disturbances) are input to the main system and the main system shakes around the fulcrum of the main system, the direction of the rotor shaft of the rotor rotating at a constant speed will change. Therefore, a gyro-moment enough to balance this motion acts on the main system to passively suppress the swing of the main system.

In controlling the swing motion of the main system, an actuator (for example, a stepping motor or a servomotor) is connected to the gimbal shaft, a sensor for detecting the swing of the main system is installed, and the sensor output is controlled by a controller. There is an idea of active type gyro vibration suppression that positively cancels the swing of the main system by calculating with and rotating the gimbal axis with an actuator.

However, the disturbance input to the main system is not always the energy within the expected range. For example, in the case of a gondola, there are usually strong winds and weak winds, but the gondolas are sprayed with a strength within the expected range, and the maximum wind speed expected at that time is used as a guide for damping. However, there are rare cases where a strong wind that is N times as strong as a normal wind blows on the gondola. In such a case, the control range of the gyro mechanism is deviated and the control becomes impossible. In other words, as will be described later, when the gimbal control angle is calculated with a constant gain obtained from the sensor output at the normally expected maximum wind speed, the actuator is operated, and the gimbal shaft is rotated to perform vibration suppression control. Has
As described above, the main system undergoes a sway exceeding the design value, such as during a typhoon, and the gimbal angle exceeds the design value, resulting in loss of control.

Therefore, in order to cope with such an abnormal condition as well, the gain should be set to be extremely small so that the gimbal control angle will have the maximum amplitude in a range not exceeding the maximum limit angle even in the abnormal condition. In this case, the damping effect works effectively in an abnormal situation, but since the gain is constant and too small, the damping effect causes the fluctuation of the main system to weaken or the fluctuation to be small. In a normal state, there is a problem that most of the capacity of the gyro mechanism is not effectively used. Further, in an actual device, the weight and cost of the object to be damped are greatly restricted, and the minimum cost and the minimum device are required to have the maximum vibration damping effect.

[0007]

The object of the present invention is to reduce the gain when the energy of the main system is excessive,
By changing the gain such that the gain is increased when the energy of the main system is attenuated or when the energy of the main system is small, the energy of the main system is too small and the gain becomes too large. In such a case, the gain is fixed to maximize the performance of the gyro mechanism.

[0008]

According to a first aspect of the present invention, there is provided a gimbal which is rotatably attached to a rotary rotor (1) and a main system (2) which supports the rotary rotor (1) and is a vibration damping target.
(3) and the actuator (5) connected to the gimbal shaft (4) to control the angle θ ₂ of the gimbal (3) and the vibration θ ₁ of the main system (2).
The gyro mechanism (A) composed of a sensor (6) for detecting the above, and a control device (7) for feeding back the calculation result based on the sensor output fetched from the sensor (6) to the actuator (5) The control gain Kv is
This is a damping method in which the energy E of the main system (2) is changed to decrease / increase contrary to the increase / decrease, and when the energy E of the main system (2) is large, the gimbal (3) by feedback control is used. for the angle theta ₂ is as the gain Kv so as not to exceed the maximum allowable angle is small, small energy E of the main system (2), the range of the angle theta ₂ of the gimbal (3) is less than or equal to the maximum allowable angle It is characterized in that the gain Kv is changed in accordance with the energy E of the main system (2).

[0009]

According to this, even if the energy E of the main system (2) is excessive, the gain Kv is reduced so that the control angle θ ₂ of the gimbal (3) does not exceed the maximum allowable angle. Therefore, the control torque u ′ ₁ based on the swing angle (= control angle θ ₂ ) of the gimbal (3) is controlled at the capacity limit of the gyro mechanism (A). When the sway of the main system (2) is gradually attenuated,
When the energy E of the main system (2) is small, the gain Kv is changed according to the energy E of the main system (2) so that the damping control of the main system (2) is effectively performed. , As a result, the main system
Gyro mechanism (A) even when energy E of (2) is excessive
It becomes possible to perform the maximum control commensurate with the capacity of the main system (2), and when the energy E of the main system (2) is normal, the optimum control suitable for the capacity of the gyro mechanism (A) becomes possible, and the capacity is excessively larger than necessary. It is not necessary to do so, and it is possible to exert the maximum damping effect with a reasonable capacity.

A third aspect of the present invention is an improvement of the first aspect, wherein the gimbal is rotatably attached to the rotary rotor (1) and the main system (2) that supports the rotary rotor (1) and is a vibration damping target.
(3) and the actuator (5) connected to the gimbal shaft (4) to control the angle θ ₂ of the gimbal (3) and the vibration θ ₁ of the main system (2).
A gyro mechanism (A) composed of a sensor (6) for detecting the sensor and a controller (7) for feeding back the calculation result based on the sensor output fetched from the sensor (6) to the actuator (5) of the gimbal (3). ), The gain Kv of the feedback control is changed so as to decrease / increase in opposition to the increase / decrease in the energy E of the main system (1), and the energy E is too small and smaller than the minimum allowable value. This is a damping method for controlling the gain Kv to be constant, and when the energy E of the main system (2) is large, the control angle θ ₂ of the gimbal (3) by feedback control does not exceed the maximum allowable angle. If the energy E of the main system (2) is small and the control angle θ ₂ of the gimbal (3) by the feedback control is less than the maximum allowable angle, the main system (2) The energy E of If the energy E of the main system (2) is smaller than the minimum permissible value and the gain Kv becomes excessive, the minimum permissible energy is set and the energy of the main system is less than this value. Is characterized in that the gain Kv is fixed with the minimum allowable energy E (= Ec) as a reference.

[0011]

In addition to claim 1, this is the addition of a point corresponding to the case where the energy E of the main system (2) is too small (E <Ec) and the gain Kv becomes too large. According to the above, when the energy E input to the main system (2) is too small and smaller than the minimum allowable energy Ec, the gain Kv is controlled so as to be fixed to a certain value. not excessive relative to the energy E of the gimbal (3) of the control torque u _'1 is the main system (2) based, it would be to stop the main system (2) quickly. Gain Kv is the main system at that time (2)
Energy E (generally the minimum allowable energy Ec) is defined as a reference.

[0012]

The method of the present invention will be described below. FIG. 1 is a perspective view showing the principle of the gyro mechanism (A) according to the present invention. As can be seen from FIG. 1, the gyro mechanism (A) used in the present invention supports a rotating rotor (1) and a main system (a main system that rotatably supports the rotating rotor (1) and is a vibration suppression target). The gimbal (3) pivotally attached to the bearing in (2) and the actuator (5) installed as a gimbal angle control device in the gimbal shaft (4).
And a sensor (6) that detects the displacement angle (sway) of the main system (2),
A control device (7) that calculates the gain Kv obtained from the captured sensor output to calculate the control angle (θ ₂ ) of the gimbal (3) driven by the actuator (5) and feeds it back to the actuator (5). ) And. The main system (2) in the present invention is like a rigid pendulum, more specifically, a ship swayed by waves, a gondola suspended from a cableway, a hanging monorail, or a crane suspended by a rope. Corresponding cargo, etc. are applicable. If we compare Fig. 1 to a gondola, in the figure, (8) is the ground, (9) is the prop that supports the cableway, (10) is the cableway, and (2) is the gondola body that corresponds to the main system. .

In the embodiment of FIG. 1, the gimbal (3) rotatably supports the rotary rotor (1) on a vertical axis, and the rotary rotor (1) rotates at a constant angular velocity. A drive device (not shown) for the rotary rotor (1) is, for example, a DC motor. In addition, the actuator (5) has a simple rotation angle and rotation speed control such as stepping
Something like a motor or servomotor is used.

First, the gimbal damping device according to the present invention.
The analysis model of (A) will be described. As described above, the rotor (1) is incorporated in the gimbal (3) and maintains a constant angular velocity with respect to the gimbal (3) by the driving device. Main system
The resistance torque against the disturbance acting on (2) is a gyro moment acting on the rotor (1), and is generated by rotating the gimbal (3) with the actuator (5). Gimbal
The gimbal about the main axis (10) by the rotation of (3)
Assuming that the moment of inertia of (3) does not change, the main system
The equation of motion of the main system (2), which has been made dimensionless using the period of (2), is as follows. θ '' _1- (α / β) ^1/2 · Ω '· θ' ₂ · cos θ ₂ + 2Z θ ' ₁ + θ ₁ = w' (1) where θ ₁ and θ ₂ are the main system (2) and gimbal Angular displacement of (3),
w ′ is a dimensionless excitation torque, Ω ′ is a rotation angular velocity of the dimensionless rotor (1), Z is a viscous damping of the main system (2), α,
β is the moment of inertia ratio. The second term of equation (1) is the damping torque to the main system (2) as a gyro moment,
'The gimbal (3) in order to obtain a ₁ distant a required damping torque, theta' which _{u 2 = (β / α)} 1/2 · [u '1 / (Ω' · cosθ 2)] It is necessary to rotate so as to satisfy (2).

[Constraint by Angular Momentum] When the gimbal angle θ ₂ reaches ± π / 2, the control torque instantaneously becomes zero,
Before and after that, the sign of the output torque is reversed. Therefore, | θ
_{2 In} the region of │> π / 2, the specified damping torque cannot be obtained. Therefore, the gimbal (3) needs to operate in the region of | θ ₂ | ≦ π / 2. If the constraint on the gimbal angle θ ₂ is │θ ₂ │≤θmax≤π / 2 (3), the torque product that can be added to the main system (2) is │∫u ' ₁ dt│ = │ (α / β) ^{1 / 2}・ Ω'∫θ ' ₂・ cos θ ₂ dt | ≤ 2 (α / β) ^1/2・ Ω' ・ sin θmax (4) There is a constraint. If there are no restrictions on the gimbal angle θ ₂ (θmax
= Π / 2), twice the rotor angular momentum is the upper limit of the torque product.

[Velocity Feedback Control] Next, the conventional constant gain control will be described, and then the variable gain control of the present invention will be described. (Constant gain control) Let the feedback gain be Kv,
The damping torque of the main system (2) is determined by u ′ ₁ = −Kv · θ ′ ₁ .
The damping torque product is │∫u ' ₁ dt│ = │Kv∫θ' ₁ dt ｜ (5), and the main system (2) is the origin (for example, in the case of a crane, when the cargo is located at the vertical point). When an impulse input of strength θ ₀ is received in a stationary state, the maximum value is 2 Kv ・
It can be approximated by θ ₀ . Comparing equation (4) and equation (5), the main system (2)
The feedback gain Kv that maximizes the damping ratio of is Kv = (α / β) ^1/2 · Ω '· sin θmax / θ ₀ (6), and as a result, the control law of gimbal (3) is as follows. Become. θ ₂ = −sin ⁻¹ [(sin θmax) · θ ₁ / θ ₀ ] (7) When the equation (7) is followed, the constraint of the gimbal angle θ _{2 in} the equation (3) is satisfied. This is not limited to the case of impulse input, but is always applicable as long as the main system amplitude in the controlled state is θ ₀ or less.

In other words, in equation (6), (α / β) ^1/2 ,
All of Ω ′, sin θmax, and θ ₀ are constants, and Kv calculated from them also has a constant value. As a result, with this constant gain control, if it is attempted to be able to cope with abnormal times as described above, the gimbal (3) control angle θ ₂ will have the maximum amplitude even within the abnormal range within the range not exceeding the maximum allowable angle. As described above, θ ₀ must be set large, that is, the gain Kv must be set extremely small, and most of the capacity of the gyro mechanism cannot be effectively used as described above.

[Variable Gain Control] According to the control rule of Equation (7) (constant gain control), when the main system amplitude | θ ₁ | exceeds θ ₀ (usually | θ ₁ | ≦ θ ₀ ). , | Θ ₂ | becomes more than θmax. Therefore, theta ₀ ^2/2 is focused on equal to the energy E of the main system immediately after receiving an impulse (2), adopts the following equation as the control law. θ ₂ = −sin ⁻¹ [(sin θmax) · θ ₁ / (2E) ^1/2 ] (8) E = (1/2) (θ ₁ ² + θ ′ ₁ ² ) (9) This is the feedback gain Kv. Is variable based on the energy E of the controlled object. That is, equation (8)
In the above, θ ₂ changes depending on the variable E, but θ ₂
Means that the feedback gain Kv for calculating θ ₂ is changing.

Rewriting this with respect to Kv, the following is obtained.
Get the expression. Kv = (α / β)^1/2・ Ω '・ sin θmax / (2E)^1/2 (10) Damping torque u'to the main system (2)₁Is u '₁=-(Α / β)^1/2[Ω '・ sin θmax / (2E)^1/2] (1-θ₁ ²/ 2E) θ '₁ + (Α / β)^1/2[Ω '・ sin θmax / (2E)^1/2] (Θ₁・ Θ '₁/ 2E) θ ''₁  It is expressed as (11).

In equation (1), w'≡ 0 and the main system is set on both sides.
The following equation can be obtained by multiplying the angular velocity θ ′ ₁ of (2) and rearranging the energy change velocity E ′ of the main system (2). {1- (α / β) ^1/2 [Ω '・ sin θmax / (2E) ^1/2 ] (θ ₁ · θ' ₁ / 2E)} E '= -2Zθ' ₁ ^2- (α / β) ^{1 / 2 [Ω '· sinθmax /} (2E) 1/2] θ' 1 2 (12) Thus, E '<condition becomes 0 ^{_{because, θ 1 = (2E) 1/2}} · cosψ, θ' _{When 1} = (2E) ^1/2 · sin ψ, E> (1/8) · (α / β) · Ω ′ ² · sin ² θmax · sin ² 2ψ (13).

The angular acceleration θ ″ ₁ of the main system (2) is expressed by the following equation. θ '' ₁ =-[{2Z + (α / β) ^1/2 [Ω '・ sin θmax / (2E) ^1/2 ] (1-θ ₁ ² / 2E)} θ' ₁ -θ ₁ ] ÷ {1 − (Α / β) ^1/2 [Ω '・ sin θmax / (2E) ^1/2 ] (θ ₁・ θ' ₁ / 2E)} (14)

FIG. 2 shows the boundary C where E'is switched between positive and negative, the contour line of the angular acceleration θ ″ ₁ of the main system (2), and the movement of the main system state quantity on the phase plane. The vertical axis represents the angular velocity θ ′ ₁ of the main system (2), and the horizontal axis represents the displacement angle θ ₁ of the main system (2). The shaded area in the figure is │θ '' ₁ │>
It is an area of 0.028 rad. When the control by the formula (8) is performed, the gimbal (3) is rotated at a very high speed in the vicinity of the boundary C (when the energy E of the main system (2) is very small and near the minimum allowable value). Become. In other words, in the equation (8), if the energy E becomes very small, the gimbal angle θ ₂ must be very large, which means that the gain Kv becomes excessive from the equation (8). , It leads to the high speed rotation of the gimbal (3) mentioned above. As a result, the angular acceleration θ '' _{1 of} the main system (2)
Will be higher. This is not a good result for vibration control. That is, the variable gain control is performed by the energy E of the main system (2).
Even if is very large, it is effective because it can be fully operated up to the limit of the gyro mechanism (A) capacity, but if the energy E is too small (when E <Ec described later), a problem remains. It will be a matter.

Therefore, the following method is adopted to solve this problem. _{E C ≧ E C min = (} 1/8) · (α / β) · Ω '2 · sin 2 θmax select the E _C such that (15), the energy of the main system (2) E <E _C
In case of, switch to control by constant gain.
E _C is the angular acceleration θ ″ ₁ to θ ″ m near the origin of the main system (2)
Determined by setting the upper limit of ax, and rotate the gimbal (3) according to θ ₂ = −sin ^-1 {[sin θmax / (2Ec) ^1/2 ] ・ θ ₁ } (16) in the region of E <E _C Let At this time, E ′ ≦ 0 in the entire area on the phase surface. In this experimental example, θ ″ max = 0.028 rad
(Dimensionless). In equation (16), [sin θmax on the right side
/ (2Ec) ^1/2 ] is a constant, and θ ₂ changes according to θ ₁ .

{Experimental Example} The experimental apparatus of the present invention is as follows. The experimental device consists of a main system, a gimbal, and a rotor, and a rotary encoder (corresponding to a sensor) is attached to the main system shaft and the gimbal shaft. The gimbal shaft is connected to the drive shaft of a pulse motor (corresponding to an actuator) with a stepped belt at a reduction ratio of 1: 4, and by sending a speed command to the pulse motor, a predetermined position (that is, control angle)
It can be rotated to (0.36 deg / pulse). Further, the rotor maintains a constant angular velocity by the DC servo motor, and the number of rotations can be set by the controller. The moment of inertia ratio of the experimental device is α = 11.6, β
= 5500, the natural frequency of the main system is 3.55 rad / s.
The rotation speed of the rotor was 2500 rpm (Ω = 0.292), and the restriction on the gimbal angle was θmax = 3π / 8.

The measuring method is as follows. The rotary encoders for the main system axis and gimbal axis are connected to the counter board in the expansion slot of the personal computer, and the count value is read into the personal computer in synchronization with the 10ms interrupts from the interval timer. From the measured angular displacement of the main system, the gimbal axis is driven by the servo system using the difference in the angular displacement of the gimbal according to the control law.

The experimental results of the present invention are as follows. The transient response from the state where the initial angle of 5.0 ° was given to the main system was measured. FIG. 3 shows the response of the main system when the constant gain is set based on the initial displacement of the main system and when the variable gain is used.
(Constant gain control) and FIG. 4 (Variable gain control) are shown. In the figure, the vertical axis represents the displacement angle of the main system and the horizontal axis represents time. The solid line, broken line, and dotted line are the results of experiments and simulations during control, and the alternate long and short dash line is the results of experiments when control is not performed.
Compared to FIG. 3, in FIG. 4, by changing the gain,
Even in a region where the main system amplitude is small, a large control torque is obtained by fully utilizing the gimbal stroke. The experimental results are in good agreement with the simulations, and control with variable gain is feasible.

[0027]

The method of the present invention confirms the damping effect of the active gyro mechanism when velocity feedback is used as a control law. By varying the gain, the energy of the damping target is affected by disturbance. It is possible to perform control without saturating the gimbal angle even if it becomes large, and to obtain a larger control torque in the region where the energy of the main system is small compared to the conventional constant gain control method. It is possible and effective.

Further, when the energy of the main system is smaller than the minimum allowable value Ec, the inconvenience of the variable gain control can be eliminated by switching from the variable gain control to the constant gain control, and the capacity of the gyro mechanism can be reduced. You can make the most of it.

[Brief description of drawings]

FIG. 1 is a perspective view showing the principle of a gyro mechanism used in the present invention.

FIG. 2 is a graph showing the movement of the main system state quantity on the phase plane.

FIG. 3 is a time-dependent response graph of a main system in conventional constant gain control.

FIG. 4 is a time response graph of a main system in the variable gain control of the present invention.

[Explanation of symbols]

(A)… Gyro mechanism (1)… Rotary rotor (2)… Main system (3)… Gimbal (4)… Gimbal shaft (5)… Actuator (6)… Sensor (7)… Control device θ ₁ … Main system Vibration θ ₂ … Gimbal angle Kv… Feedback gain E… Energy of main system

Claims (4)

[Claims] 1. A rotating rotor, a gimbal that supports the rotating rotor and is rotatably attached to a main system to be damped, an actuator that is connected to a gimbal shaft, and controls the angle of the gimbal, and a main system. With a gyro mechanism composed of a sensor for detecting vibration and a control device for feeding back the calculation result based on the sensor output fetched from the sensor to the gimbal actuator, the gain of the feedback control increases the energy of the main system. This is a damping method that changes so as to decrease or increase in a manner that goes against the decrease, and when the energy of the main system is large, the gain should be reduced so that the gimbal angle by feedback control does not exceed the maximum allowable angle. If the energy of the main system is small, the gimbal angle of the main system will be within the maximum allowable angle. Damping method according to the gyro mechanism, characterized in that changing the gain in accordance with the Nerugi. 2. The vibration control method by a gyro mechanism according to claim 1, wherein the control angle of the gimbal is controlled by the following equation. θ ₂ = −sin ⁻¹ [(sin θmax) ・ θ ₁ / (2E) ^1/2 ] ………… (I) E = (1/2) (θ ₁ ² + θ ′ ₁ ² ) ……………… …………… (II) │ θ ₂ │ ≤ θmax ≤ π / 2 …………………………………… (III) where θ ₂ is the gimbal control angle θmax is the gimbal Maximum displacement angle θ ₁ is the displacement angle of the main system E is the energy of the main system θ ′ ₁ is the angular velocity of the main system 3. A rotary rotor, a gimbal that supports the rotary rotor and is rotatably attached to a main system that is a vibration suppression target, an actuator that is connected to a gimbal shaft and controls the gimbal angle, and a main system With a gyro mechanism composed of a sensor for detecting vibration and a control device for feeding back the calculation result based on the sensor output fetched from the sensor to the gimbal actuator, the gain of the feedback control increases the energy of the main system. A damping method in which the gain is controlled to be fixed when the energy is too small and smaller than the minimum allowable energy, when the energy of the main system is large. , The gain is small so that the gimbal control angle by feedback control does not exceed the maximum allowable angle. When the energy of the main system is small and the gimbal control angle by feedback control is less than the maximum allowable angle, the gain is changed according to the energy of the main system and the energy of the main system is the minimum allowable value. If the gyro mechanism is smaller, the minimum allowable energy is set when the gain becomes excessive, and when the main system energy is less than this, the gain is fixed with the minimum allowable energy as a reference. Vibration control method. 4. When the main system energy is equal to or higher than the minimum allowable energy of the variable gain control and the gain is variably controlled, the gimbal control angle calculated by the gain is expressed by the formulas (I) to (III). The gyro mechanism according to claim 3, wherein the gimbal control angle is controlled by the equation (IV) when the main system energy is smaller than the minimum allowable energy and the gain is fixed control. Vibration control method. θ ₂ = −sin ⁻¹ [(sin θmax) ・ θ ₁ / (2E) ^1/2 ] ………… (I) E = (1/2) (θ ₁ ² + θ ′ ₁ ² ) ……………… …………… (II) │ θ ₂ │ ≤ θmax ≤ π / 2 ………………………………………… (III) θ ₂ = −sin ^-1 [(sin θmax) ・ θ ₁ / (2Ec) ^1/2 ] (IV) where θ ₂ is the gimbal control angle θmax is the gimbal maximum displacement angle θ ₁ is the main system displacement angle E is the main system energy θ ′ ₁ is the main system Angular velocity Ec is the minimum allowable energy for variable gain control