JP2001173713A - Vibration reducing method and device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce ROM necessary for a vibration reducing device and suppress the enlargement of a system scale. SOLUTION: The vibration frequency of an engine 3 is taken in a controller 5 with a frequency sensor 7, and acceleration applied to a sheet 2 is taken in the controller 5 with an acceleration sensor 8. The controller 5 supplies a vibration output for canceling the vibration in a vibration system estimated with an adaptive algorithm operation unit 6 to an actuator 4 through an power amplifier 9, and the vibration of the engine is actively suppressed. A filter coefficient of an adaptive digital filter is updated based on an error signal from the acceleration sensor 8. Before starting control, in the engine stopped state, amplitude characteristics from the signal output of the controller 5 to the signal input by the acceleration sensor 8 are measured by the following procedure. Phase characteristics obtained by Hilbert transform of the amplitude characteristics are used to update the filter coefficient.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for reducing vibration, and more particularly to a method and apparatus for reducing periodic vibration.

[0002]

2. Description of the Related Art When an unknown system can be approximated by an FIR (finite response) filter, that is, a non-recursive filter, its parameters, that is, an impulse response, are estimated to obtain the same output as that of the unknown system. It is. That is, adaptive signal processing means estimating parameters of an unknown system. For example, if an engine vibration system is analyzed as an unknown system, a vibration reduction device that generates a pseudo vibration and actively cancels the engine vibration is provided. Can be constructed.

The conventional vibration reducing device shown in FIG. 2 reduces vibration of an engine 3 transmitted to a seat 2 such as a driver's seat by vibrating an actuator 4 mounted on an engine mount. 1
In 0, an adaptive algorithm operation unit 6 is incorporated. The vibration frequency of the engine 3 is captured by the controller 10 by the frequency sensor 7, and the acceleration applied to the seat 2 is captured by the controller 10 by the acceleration sensor 8. The controller 10 includes the adaptive algorithm calculator 6
The vibration output that cancels the vibration of the vibration system estimated by the above is supplied to the actuator 4 via the power amplifier 9 to actively suppress the vibration of the engine.

The conventional vibration reducing apparatus shown in FIG. 2 uses, for example, a synchronous LMS (least mean square) algorithm, so-called SFX algorithm, as an adaptive algorithm. The SFX algorithm generates an impulse train synchronized with the fundamental period of a periodic signal or a pseudo-periodic signal in the processor, and uses this as a virtual input to which the filtered XLMS algorithm can be applied. Since the signal and the reference signal can be generated only for the necessary ones, the convolution operation is unnecessary and the operation amount is small,
Further, there is an advantage that the control ability can be improved by increasing the sampling frequency.

However, since the SFX algorithm processes a periodic signal such as engine vibration, the sampling frequency also increases in accordance with the upper limit of the frequency, and it is necessary to increase the order of the number of taps of the impulse response. Therefore, there is a problem that the sampling period becomes longer as the processing time increases, and the calculation accuracy also decreases.

Therefore, in order to remove a specific frequency component of a periodic signal, a sine wave output signal is included as disclosed in "Adaptive control method of periodic signal" disclosed in Japanese Patent Application Laid-Open No. 8-44377. The evaluation function represented by the square of the function is
A gradient vector is obtained by partially differentiating using a filter coefficient of an estimation system, which is a function of the amplitude and phase of the sine wave output signal, and a value obtained by multiplying the gradient vector by a constant number is subtracted from the filter coefficient to obtain a time. An adaptive algorithm has been proposed in which the filter coefficient is updated every elapse, and the amplitude and phase of the sine wave output signal are updated based on the updated filter coefficient amplitude and phase.

In this method, the updating of the filter coefficient W is as follows.

[0008]

(Equation 1)

Here, n is time, ω is angular frequency, T is sampling period, μa and μp are step size parameters, e is an error signal, and ak and φk represent the amplitude and phase of the k-th output signal. Step size parameter μa
And μp are determined experimentally in consideration of convergence stability and calculation speed. Output signal amplitude and phase ak, φ
The k initial value is set to, for example, 0.

JP-A-8-44377 further discloses that
An adaptive control method of a periodic signal is disclosed in which the amplitude and the phase of the sine wave output signal are updated based on phase information of a system obtained in advance. In this case, assuming that the delay due to the transmission of the k-th order system is mk, it is only necessary to replace n with n-mk for terms other than the instantaneous error (e) in the above equation (1).

This adaptive algorithm can be operated only from the basic period of the periodic signal, and does not require a convolution operation for generating a filter coefficient and a reference signal. Also,
Since the sampling period is constant, there is such a feature that the calculation is not sacrificed due to an increase in the frequency, and the result is improved.

[0012]

In the conventional vibration mitigation method, a synchronous adaptive algorithm is used as an adaptive algorithm. The equivalent transfer characteristic of a control target system for generating a reference signal is enormous for both phase data and amplitude data. R
OM data is required, and there is a problem that the system scale is easily enlarged.

The present invention has solved the above-mentioned problem. Before starting the control, the target system is identified and the necessary R value is obtained by using the Hilbert transform.
The purpose is to reduce the OM data by half and to suppress the system scale.

[0014]

According to the present invention, there is provided a vibration reducing method for actively suppressing a vibration system by applying a vibration having an opposite phase to an original vibration by using an adaptive digital filter according to a least mean square algorithm. Only the amplitude characteristic of the vibration system is identified, the phase characteristic of the vibration system is calculated by Hilbert transform of the amplitude characteristic, and the filter coefficient of the adaptive digital filter is updated using the phase characteristic.

According to the present invention, there is provided a vibration reducing method for actively suppressing a vibration system by applying a vibration having a phase opposite to the original vibration by using an adaptive digital filter, wherein the adaptive digital filter includes a sine wave output signal. The gradient vector is obtained by partially differentiating the evaluation function represented by the square of the function by a filter coefficient that is a function of the amplitude and phase of the sine wave output signal, and a value obtained by multiplying the gradient vector by a constant number is obtained from the filter. The filter coefficient is updated every time by subtraction, and the amplitude and the phase of the sine wave output signal are updated by the amplitude and phase of the updated filter coefficient based on the phase characteristic obtained by Hilbert transforming the amplitude characteristic of the vibration system obtained in advance. And updating the phase.

According to the present invention, there is provided a vibration reducing method for actively suppressing the vibration of a vehicle by applying an anti-vibration to the engine of the vehicle using an adaptive digital filter according to a least mean square algorithm. Only the characteristics are identified, and the phase characteristics of the vehicle are calculated by Hilbert transform of the amplitude characteristics, and the filter coefficients of the adaptive digital filter are updated using the phase characteristics.

The present invention relates to an automobile engine (3 in FIG. 1).
By driving an actuator (4 in FIG. 1) mounted on the vehicle and exciting the engine, vibration of a seat (2 in FIG. 1) of the vehicle is detected by an acceleration sensor (8 in FIG. 1) to thereby control the vehicle. The amplitude characteristic of the adaptive digital filter is calculated in accordance with a least mean square algorithm based on the phase characteristic obtained by Hilbert transform of the amplitude characteristic and the vibration of the vehicle seat detected by the acceleration sensor, and the frequency characteristic is calculated. An actuator mounted on the engine is driven by a signal obtained by passing the original vibration of the vehicle engine detected by a sensor (7 in FIG. 1) through the adaptive digital filter.

[0018] The vibration reducing apparatus of the present invention includes means for applying an anti-vibration to the engine of a vehicle by using an adaptive digital filter according to a least mean square algorithm.
Means for identifying only the amplitude characteristic of the vehicle, means for calculating the phase characteristic of the vehicle by Hilbert transforming the amplitude characteristic, and means for updating the filter coefficient of the adaptive digital filter using the phase characteristic. It is characterized by including.

The vibration reducing device of the present invention is mounted on an engine (3 in FIG. 1) of an automobile, and an actuator (4 in FIG. 1) for exciting the engine, and a frequency sensor (FIG. 1) for detecting the vibration of the engine. 7), an acceleration sensor (8 in FIG. 1) for detecting vibration of a seat (2 in FIG. 1) of the automobile, and identification by detecting vibration of the seat when the actuator is driven by the acceleration sensor. A filter coefficient of an adaptive digital filter is calculated according to a least mean square algorithm based on a phase characteristic of the vehicle obtained by performing the Hilbert transform on the obtained amplitude characteristic and a vibration of a seat of the vehicle detected by an acceleration sensor, and is detected by the frequency sensor. A controller for driving the actuator with a signal obtained by passing the original vibration of the engine of the vehicle through the adaptive digital filter. Characterized in that it comprises a (5 in FIG. 1) and.

[0020]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a configuration diagram of a vibration reduction device according to an embodiment of the present invention.

The vibration reduction device shown in FIG. 1 reduces vibration of an engine 3 transmitted to a seat 2 such as a driver's seat of an automobile by vibrating an actuator 4 mounted on an engine mount. An adaptive algorithm calculator 6 is incorporated in 5. The vibration frequency of the engine 3 is captured by the controller 5 by the frequency sensor 7, and the acceleration applied to the seat 2 is captured by the controller 5 by the acceleration sensor 8. The controller 5 supplies a vibration output that cancels the vibration of the vibration system estimated by the adaptive algorithm calculator 6 to the actuator 4 via the power amplifier 9 to actively suppress the vibration of the engine.

The input signal from the frequency sensor 7 passes through an adaptive digital filter in the adaptive algorithm 6 and is supplied to the power amplifier 9 as an output signal. The filter coefficient of the adaptive digital filter is updated by the above equation (1). In this case, an error signal is obtained from the acceleration sensor 8.

Before starting the control, the amplitude characteristic from the signal output of the controller 5 to the signal input by the acceleration sensor 8 is measured in the following order with the engine 3 stopped. The actuator 4 is driven through the power amplifier 9 by the output signal of the controller 5 to vibrate the engine 3. The vibration transmitted to the seat 2 is taken into the controller 5 through the acceleration sensor 8. This changes the frequency of the excitation over the used band.

The amplitude characteristic thus obtained is subjected to the Hilbert transform shown below to calculate a phase characteristic, ie, mk. If the transfer characteristic is H (exp (jω)), the amplitude characteristic is | H
(Exp (jω)) |. The phase characteristic is

[0026]

(Equation 2)

Can be calculated.

After starting the engine 3, the controller 5 drives the actuator 4 through the power amplifier 9 so that the output of the acceleration sensor 8 becomes 0 by the adaptive algorithm 6 when the control is started.

[0029]

As described above, according to the present invention,
Since the Hilbert transform is used, it is only necessary to identify the amplitude characteristic, and the system can be designed with half the size of the conventional ROM, so that the system can be made thinner and an excellent effect can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a vibration reduction device according to an embodiment of the present invention.

FIG. 2 is a schematic configuration diagram of a conventional vibration reduction device.

[Explanation of symbols]

 2 Seat 3 Engine 4 Actuator 5 Controller 6 Adaptive algorithm calculator 7 Frequency sensor 8 Acceleration sensor 9 Power amplifier 10 Controller

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (reference) G10K 11/16 G10K 11/16 H 9A001 H03H 21/00 J F term (reference) 3D035 CA23 3J048 AB11 AD02 EA01 EA36 5D061 FF02 GG10 5H004 GB12 HA12 HB08 HB09 JB30 KA32 KB21 KC12 MA11 5J023 DB03 DC06 DC08 DD07 DD08 9A001 EE02 FF01 GG03 HH34 KK29 KK32

Claims (6)

[Claims] 1. A vibration reduction method for actively suppressing a vibration system by applying a vibration having an opposite phase to an original vibration using an adaptive digital filter according to a least mean square algorithm, wherein only an amplitude characteristic of the vibration system is identified. And a phase characteristic of the vibration system is calculated by Hilbert transform of an amplitude characteristic, and a filter coefficient of the adaptive digital filter is updated using the phase characteristic. 2. A vibration reduction method for actively suppressing a vibration system by applying a vibration having a phase opposite to that of an original vibration using an adaptive digital filter, wherein the adaptive digital filter includes a function having a sine wave output signal. A gradient vector is obtained by partially differentiating the evaluation function represented by the square with a filter coefficient which is a function of the amplitude and phase of the sine wave output signal, and a value obtained by multiplying the gradient vector by a certain number is subtracted from the filter. Thus, the filter coefficient is updated every time, and the amplitude and phase of the sine wave output signal are updated based on the amplitude and phase of the updated filter coefficient based on the phase characteristic obtained by Hilbert transforming the amplitude characteristic of the vibration system obtained in advance. The method for reducing vibrations, characterized in that: 3. A vibration reduction method for actively suppressing a vehicle by applying an anti-phase vibration to an engine of the vehicle using an adaptive digital filter according to a least mean square algorithm, wherein the amplitude characteristic of the vehicle is only A phase characteristic of the vehicle is calculated by Hilbert transform of an amplitude characteristic, and a filter coefficient of the adaptive digital filter is updated using the phase characteristic. 4. An amplitude characteristic of the vehicle is identified by driving an actuator attached to the engine of the vehicle and detecting vibration of a seat of the vehicle when the engine is excited by an acceleration sensor. The filter coefficient of the adaptive digital filter is calculated in accordance with a least mean square algorithm based on the phase characteristics obtained by performing the Hilbert transform and the vibration of the vehicle seat detected by the acceleration sensor, and the original value of the engine of the vehicle detected by the frequency sensor is calculated. A vibration reduction method, comprising driving an actuator attached to the engine with a signal obtained by passing vibration through the adaptive digital filter. 5. A means for applying an anti-vibration to an engine of a vehicle using an adaptive digital filter according to a least mean square algorithm, a means for identifying only the amplitude characteristics of the vehicle, and a Hilbert transform of the amplitude characteristics. And a means for calculating a phase characteristic of the vehicle, and means for updating a filter coefficient of the adaptive digital filter using the phase characteristic. 6. An actuator mounted on an engine of a vehicle for exciting the engine, a frequency sensor for detecting vibration of the engine, an acceleration sensor for detecting vibration of a seat of the vehicle, and when the actuator is driven. Adaptation according to a least mean square algorithm based on the phase characteristics of the vehicle obtained by Hilbert transforming the amplitude characteristics identified by detecting the vibration of the seat by the acceleration sensor and the vibration of the vehicle seat detected by the acceleration sensor. Calculate the filter coefficient of the digital filter,
A controller that drives the actuator with a signal obtained by passing the original vibration of the vehicle engine detected by the frequency sensor through the adaptive digital filter.