JPH03282032A - Active vibration control method and control device thereof - Google Patents

Abstract

PURPOSE:To reduce all vibration in a multidegree of freedom system by a method wherein a feedback signal forms a vibration response (a speed component), classified by a single frequency, to each natural frequency of an object to be dampered. CONSTITUTION:A signal processing part factorizes an input signal into a vibration response (a speed component), classified by a single frequency, to each natural frequency of an object to be dampered by using a narrow band-pass filter 5. After multiplication of each signal by a feedback gain by means of a voltage amplifier 6, a phase is inverted by a phase inverter 7, where occasion demand, so that feedback control is stabilized. Composition of results is effected by an adder 8 to provide a control signal having frequency characteristics as shown in a diagram. A control signal converted in a manner described above by the signal processing part is inputted to a power amplifier 9 to drive an actuator 2. In this way, a feedback control system using an output (the speed component of a response separated classified by a signal frequency) is formed, and the generation of all vibration of an object to be damped is reduced.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to an active vibration control method used as a vibration damping device for general mechanical structures such as ships, steel structures, and various types of ports, and its control. Regarding equipment.

[Conventional technology]

Conventionally, as a method of actively controlling vibration, so-called output feedback control is used to drive an actuator using a signal that is proportional to the vibration velocity of the vibration damping target detected by a sensor and has an opposite phase. Methods have been proposed to reduce vibration by increasing the appearance.

[Problem to be solved by the invention]

FIG. 6 shows an example of a damping device constructed using conventional output feedback control. In FIG.

1 is a vibration damping target; 2 is an actuator; 3 is a vibration detection sensor; 4 is a charge amplifier; 6 is a voltage amplifier; 1 is a phase inverter.

According to the conventional method, vibration can be suppressed in a one-degree-of-freedom system or a part of a multi-degree-of-freedom system, but in a general multi-degree-of-freedom system, it is not necessarily possible to suppress all vibrations at low frequencies. That is, if the phase characteristics of the transfer function (mobility) between the excitation force of the actuator 2 and the point response of the sensor 3 are always in phase at the resonance point, stable feedback control will not be achieved.

However, generally, as shown in FIG. 7, the resonance point W1. W
The phase at 2°W3 is a mixture of in-phase and anti-phase inputs. Therefore, as shown in FIG. 8, in the root locus of the feedback system, some of the characteristic roots become stable, while others become unstable. The resulting vibration response is shown in Figure 9.
This response increases when the 411F root is stabilized.

As described above, the conventional method has the problem that not all vibrations can necessarily be reduced.

The present invention has been made in view of the above points, and an object of the present invention is to provide an active vibration control method and a control device thereof that can reduce all vibrations in a multi-degree-of-freedom system.

[Means to solve the problem]

That is, in the present invention, the feedback signal is a vibration response (velocity component) for each single frequency with respect to each natural frequency of the damping target. Specifically, the following formula (1
) as shown in the second-order lag element and the first-order differential 9! It is expressed as a transfer function that combines elements, and the frequency f as shown in Figure 3
Create a narrow band pass filter with no phase change between input and output at l, input the signal detected by the vibration detection sensor in parallel to the above narrow band pass filter, and generate a signal for each frequency to be focused on as a vibration suppression target. Separate into Each separated signal is multiplied by the feedback gain,
By inverting the phase and adding it to achieve stable feedback control as necessary, a control signal to be fed back is obtained, thereby achieving always stable output feedback control.

Transfer function representing the characteristics of a narrow band pass filter Here, S nira plus operator W, = 2πf1: Center frequency (frequency you want to pass) Q: Resonance magnification: Proportionality coefficient [effect] According to the above configuration, the feedback signal is the vibration response (velocity component) for each single frequency for each natural frequency of the damping target, so each output obtained is a response at each resonance frequency, and the phase relationship of the transfer function with the actuator excitation force are always in phase as shown in FIG. Therefore, the root locus of the feedback system is the fourth
As shown in the figure, all characteristic roots move toward stability. As shown in FIG. 5, the vibration response obtained as a result can be damped for all vibration modes focused on as damping targets, and the vibration response can be reduced.

〔Example〕

Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

Figure 1 is a schematic configuration diagram of the active vibration control device of the same embodiment (a diagram showing the signal transmission path), and Figure 2 is the output of the Fi signal processing section (
Fig. 3 is a diagram showing an example of the input/output transfer function of a narrow band pass filter.
The figure shows an example of a pole position on the S plane when using this device, and FIG. 5 is a diagram showing an example of a vibration response when using this device.

As shown in FIG. 1, a vibration detection sensor 3 is installed on the vibration damping target J, and a charge amplifier 4 converts it into a voltage representing the vibration speed. If the sensor 3 is an acceleration sensor, the charge amplifier 4 should have a first-order integration function, and if the sensor 3 is a displacement sensor, the charge amplifier 4 should have a first-order differentiation function, or an integrator or differentiator should be added. do it. Further, 5 is a narrow band pass filter, and 6 is a voltage amplifier.

7 is a phase inverter, 8 is an adder, 10 is a changeover switch, and 5 to 10 are signal processing units.

The signal processing section uses a plurality of narrow band pass filters 5 having characteristics as shown in FIG. 3 to calculate the vibration response (
(velocity component). Then, by the voltage amplifier 6,
After each signal is multiplied by the feedback gain, the phase is inverted by the phase inverter 2 so as to achieve stable feedback control (an example of which is shown in FIG. 4), and the adder 8 Synthesize each and create the second
A control signal having frequency characteristics as shown in the figure is obtained.

By inputting the control signal converted by the signal processing unit as described above to the power amplifier 9 and driving the actuator 2, feedback using the output (velocity component of the response separated for each single frequency) is performed. Configure the control system and
As shown in the figure, this is an attempt to reduce all the vibrations of the damping target.

Here, to describe the frequency determination method of the narrow band pass filter 5, the transfer function between the actuator and the sensor is measured when the vibration damping target 1 is excited by the control actuator 2, and an appropriate frequency is determined according to the measurement result. A frequency shall be selected. Further, on/off settings of the switch 100 are performed for each frequency based on the phase obtained at this time.

In FIG. 7, the peak (resonance point) W of @1.

In this case, the phases of the actienne taka and the sensor response are in phase (phase difference 0°). Therefore, if the actuator is driven with a signal whose phase is inverted from that of the observed signal, a control force with a phase opposite to the excitation force will not be applied, and the response will be small. -1 2nd. Third peak (resonance point) W2. W,
In this case, the phases of the actinihawk and the sensor response are opposite to each other (phase difference: 180°). Therefore, if the actuator is driven with a signal that has the phase of the observed signal inverted, a control force that is in phase with the excitation force will be further applied, and the response at this frequency will conversely increase.

By the way, with the conventional method shown in Figure 6, it is impossible to control the phase by changing the phase for each peak, and if one peak is made smaller, other peaks will inevitably become larger (in extreme cases). becomes negatively attenuated and diverges). On the other hand, according to the method shown in FIG. 1, since the control P-in and phase can be determined separately for each peak, all peaks can be made small.

〔Effect of the invention〕

As detailed above, according to the present invention, the following effects can be obtained.

The feedback signal is the velocity component of the vibration response separated for each single frequency of the vibration damping target, and the phase is reversed as necessary to ensure stable feedback control. It is possible to reduce the vibration response for all natural frequencies.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing the configuration of an active vibration control device according to an embodiment of the present invention, and Fig. 2 is an output of the signal processing section of the embodiment (velocity component of response separated for each single frequency). FIG. 3 is a diagram showing the input/output transfer function of the narrow band pass filter of the same embodiment.
FIG. 4 is a diagram showing the pole position on the S plane in the same embodiment, FIG. 5 is a diagram showing the vibration response of the same embodiment, and FIG. 6 is a block diagram showing the configuration of a conventional active vibration control device. FIG. 7 is a diagram showing the transfer function of the output (velocity signal at the observation point) and actuator excitation force according to the conventional method. FIG. 8 is a diagram showing the pole position on the S plane according to the conventional method, and FIG. 9 is a diagram showing the conventional vibration response. 1... Snow shoveling object, 2... Actieator, 3...
Vibration detection sensor, 4... Charge amplifier, 5... Narrow band pass filter, 6... Voltage amplifier, 2... Phase inverter. 8... Addition a, p-... Power amplifier (power amplifier)
. 10... Selector switch.

Claims (2)

[Claims] (1) In a vibration damping device that actively damps the vibration of a damped object in a multi-degree-of-freedom system by output feedback control, the feedback signal is a vibration response for each single frequency for each natural frequency of the damped object. The signal obtained as the output of the vibration sensor installed on the vibration damping target is input to a narrow band pass filter with no phase change between input and output, and is separated into signals for each frequency to be focused on as the vibration damping target. Multiply each signal by the feedback gain,
An active vibration control method characterized in that a control signal to be fed back is obtained by inverting the phase and adding it to achieve stable feedback control as necessary. (2) A vibration detection means for detecting the vibration of the damping target, a plurality of filter means for separating the output signal of the vibration detection means into signals of each predetermined frequency, and each signal separated by the filter means. An amplifying means for multiplying by a feedback gain, a phase inverting means for inverting the phase of each signal multiplied by the feedback gain by the amplifying means as necessary, and an adding means for adding each signal inverted by the phase inverting means. An active vibration control device comprising: and a vibration excitation device that vibrates the vibration damping target based on the output signal of the addition device.