JP2000018316A - Active controlling device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To appropriately realize a correction against a variation of a presumed transfer function against a variation of a using environment of a vehicle and a deterioration with age without giving an uncomfortableness to a passenger by successively renewing a presumption transfer function data previously defined by the presumption transfer function calculated. SOLUTION: When it is a measuring time, a measurement of a transfer function is started. Namely, an excitation signal is spotly outputted at an interval of 1 Hz in a frequency range of 20 to 22 Hz and excitation of an actuator 23 is carried out. A vibration due to the excitation is inputted to a controlling portion by a pick up acceleration sensor 14 and a presumption transfer function value is calculated based on the result. A presumption transfer function data calculated is rewritten with a presumption transfer function data memorized in a data table RAM 41. Since measuring time of the presumption transfer function is short time of 0.5 second or less and a spot excitation is carried out, the excitation operation is not felt by a passenger and an uncomfortableness due to the excitation operation is not given to the passenger.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an active control device for actively suppressing vibration of a vehicle body.

[0002]

2. Description of the Related Art Conventionally, as an active control device for an engine mount of an automobile, as shown in FIG. 5, for example, as shown in FIG. It is known that a control unit 40 is provided to perform active control of vehicle vibration. That is, a crankshaft rotation pulse or the like is extracted by the sensor 12 from the engine 11 of the automobile as a signal source, and the adaptive control unit 40
The control target frequency ω is determined and the control target frequency ω
Select and output the control target signal of DXHS LMS
The amplitude compensation and the phase compensation are performed by the filter coefficient of the filter, and the sine wave signal is synthesized and output. The output signal is
The power is amplified by the power amplifier 32 and input to the vibrator 23, and the vibrator is vibrated to suppress the vehicle body vibration. On the other hand, an external force signal having a frequency to be controlled is detected by a pickup acceleration sensor 14 attached to the seat 13 of the automobile M, and is used for updating control of the adaptive filter.

Here, an adaptive control method using a DXHS LMS filter is based on an adaptive least mean square filter (Filtered-X LM).
This is to reduce the calculation amount of the filter coefficient in S), and is performed as follows. In this adaptive control, as shown in FIG. 6, a crankshaft rotation pulse or the like is transmitted from a vibration source 51 such as an automobile engine as a signal source to a sensor 1.
2, the signal s is extracted, and the frequency determination unit 61 determines that the signal is the control target frequency ω, and the control target frequency ω
Is selected and output to the adaptive filter W62. The input signal x is amplitude- and phase-compensated by the filter coefficient of the adaptive filter W62, is synthesized into a sine wave signal, and is output. The output signal y is the control target system 63
(Transfer function G), and the processed signal z is output.
The processing signal z is a signal transmission system 52 such as an engine vibration.
The external force d passing through (G ') is added and detected by the sensor as an observed value. In the vibration control, the target of the detection value of the sensor is 0, and the difference from the target becomes the error signal e. Using the error signal e and the estimated value of the estimated transfer function 64, the adaptive filter W is sequentially updated by the digital filter 65 (DXHS LMS) as described below. First, an external force signal d (target signal) having a periodicity to be controlled is expressed by the following equation (1).
Is represented by

[0004]

D = B.exp [j (ω ^* t + φ ^* )]

Note that ω ^* indicates the angular frequency of the control target signal, and B and φ ^* indicate the amplitude and phase of the control target signal, respectively. Further, the periodic signal x is represented by the following equation 2,
The adaptive filter W is expressed by the following equation 3, and the transfer function G is expressed by the following equation 4.

[0006]

X = X · exp [jωt]

[0007]

W = [a, φ]

[0008]

G = [A, Φ]

Note that ω represents the angular frequency of the periodic signal, and X represents the amplitude. A and φ represent an amplitude compensation coefficient and a phase compensation coefficient. Further, A and Φ represent an amplitude transfer function and a phase transfer function. The output signal y of the adaptive filter W and the output signal z of the transfer function G are as shown in Expressions 5 and 6 below.

[0010]

Y = Xa · exp [j (ωt + φ)]

[0011]

## EQU6 ## z = XaA.exp [j (ωt + φ + Φ)]

The angular frequency ω ^* of the external force d is derived from a known input signal such as a crankshaft rotation pulse signal or an ignition pulse signal from the external sensor, and is assumed to be equal to the angular frequency ω of the output signal. Further, the instantaneous mean square error J is expressed by the following equation (7).

[0013]

J = e ² = (z + d) ²

The updating formula of the adaptive filter is as shown in the following equation (8).

[0015]

(Equation 8)

When the gradient vector ▽ is obtained by using the above formulas 1, 6 and 7, it is expressed by the following formula 9.

[0017]

(Equation 9)

Here, since the amplitude and the phase are calculated independently of each other, the step size parameters of the amplitude and the phase are expressed as μa and μp, respectively, in the update formula for updating the filter coefficient. Also, since the true value of the transfer function is unknown, by replacing it with an estimated value (indicated by ＾), the update equation of the filter coefficient becomes
It will be like 0.

[0019]

(Equation 10)

As described above, the above algorithm does not require a convolution operation for updating a coefficient, and does not require a convolution operation for generating a reference signal. Therefore, in the case of periodic vibration or noise, When the fundamental wave and its higher-order components are to be controlled, an external harmonic signal is not required for input.

In the above adaptive control, the estimated transfer function 64
Is obtained in advance by a frequency sweep excitation or an impulse response measurement test or the like. The transfer function G is obtained by mapping an estimated value of the transfer function (G) of the control target system, which is denoted by ＾, with respect to the frequency in the control program, and is referred to when the adaptive filter is updated.

[0022]

By the way, when an active control device is applied to a vehicle, the estimated transfer function is conventionally adjusted only at the time of shipment of the vehicle. When the estimated transfer function changes due to a temporal change or the like, there is a possibility that the effect of the vibration control may not be properly exhibited. For example, there is a possibility that a problem such as deterioration of the noise vibration harness or divergence of the transmission characteristics of the control device may occur. On the other hand, the estimated transfer function may be appropriately measured and updated, but when the estimated transfer function is measured, sweep vibration or the like must be performed to continuously apply vibration to the vehicle body. Measurement would not be possible during normal operation because it would cause discomfort to the occupants.

The present invention is intended to solve the above-described problem, and corrects a change in an estimated transfer function due to a change in a use environment of a vehicle or a change with time without appropriately giving a passenger an unpleasant feeling. It is an object of the present invention to provide an active control device that can perform the control.

[0024]

Means for Solving the Problems and Effects of the Invention In order to achieve the above object, a structural feature of the invention according to claim 1 is that an input based on a periodic pulse signal from a vibration source of a vehicle is provided. The signal is subjected to amplitude compensation and phase compensation by a filter coefficient which is a function of an amplitude compensation coefficient and a phase compensation coefficient of an adaptive filter, and further processed by a transfer function of a controlled system of a vehicle. The external force from the source is added, and a digital filter is used based on an error resulting from the addition and an estimated transfer function processing signal obtained by subjecting the input signal to amplitude and phase processing based on a predetermined estimated transfer function of the control target system of the vehicle. An active control device that sequentially updates the filter coefficients of an adaptive filter and controls the vibration of the vibrator by the adaptive filter to actively suppress vehicle body vibration. During the engine operation of the vehicle, the vibrator is vibrated for a short time at an arbitrary time interval by the signals of a plurality of frequency groups randomly selected over the entire range of the predetermined frequency corresponding to the estimated transfer function data, An estimated transfer function is calculated by measuring a response due to vibration, and the estimated transfer function data specified in advance is sequentially updated by the calculated estimated transfer function.

According to the first aspect of the present invention, the vibration by the signal of the frequency group selected at random is applied to the vehicle body within a short time that the occupant does not feel during the operation of the engine of the vehicle. Since it is sufficient to add the vibration, the vibration caused by the vibration does not give the occupant any discomfort due to the vibration. Further, during the operation of the engine, the estimated transfer function is measured at an arbitrary time interval, and the estimated transfer function is updated based on the measured value. Therefore, it is possible to always maintain the estimated transfer function in an appropriate state. And appropriate vibration control can be performed.

According to a second aspect of the present invention, in the active control apparatus according to the first aspect, the excitation frequency is controlled based on an adaptive filter. It is different from the frequency. With the configuration of the second aspect of the invention as described above, it is possible to reliably measure the estimated transfer function by performing excitation using a frequency different from that while appropriately performing excitation control.

[0027]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG.
DXHS for vibration reduction of 4-cycle gasoline engine vehicles
FIG. 2 schematically shows an active control device using an LMS filter, and FIG. 2 is a block diagram showing an adaptive control system using a DXHS LMS filter.

The gasoline engine vehicle M has an engine mount (hereinafter, referred to as an engine mount) 20 with an actuator mounted on a vehicle body 10. Engine mount 2
0 has a substantially cylindrical case 21 whose both ends are sealed as shown in FIG. 3, for example. The case 21 has an annular convex portion 21 bulging coaxially outward at a substantially middle position in the axial direction.
A substantially disk-shaped anti-vibration rubber 22 is coaxially fixed along the circumferential direction on the inner wall side of the annular convex portion 21a. The anti-vibration rubber 22 has an axial cross-sectional shape projecting toward the one end side (upper end in the figure) of the case 21 in a mountain shape, and a substantially inverted conical fixing bracket 24 is coaxially fixed to the top side of the mountain shape. I have. An annular stopper portion 22a is provided at the periphery of the flat surface (the upper end surface in the figure) of the fixing bracket 24 so that the vibration-proof rubber 22 is protruded toward one end of the case 21. Further, at the axial center position of the flat surface of the fixing bracket 24,
A fixed shaft 25 is coaxially mounted, and a tip of the fixed shaft 25 projects from a through hole 21 b provided at one end of the case 21. The fixed shaft 25 has a screw hole at an axial center position.

An actuator 23 which is a vibrator for controlling the dynamic displacement of the engine is provided on the opposite side (lower side in the figure) of the vibration isolating rubber 22 in the case 21. Case 21
On the other end side (the lower end in the figure), a fixed shaft 26 having a thread groove is provided.
Are provided coaxially. This engine mount 2
Numeral 0 is fixed to the vehicle body 10 by a fixed shaft 26, and elastically supports the engine 11 by attaching the engine 11 to the fixed shaft 25.

A rotary pulse sensor 12 is provided on the crankshaft of the engine 11.
Outputs a crankshaft rotation pulse signal, and based on this, a control unit 31 described later determines a fundamental frequency of the output signal. Further, a pickup acceleration sensor 14 for detecting a rotation speed (frequency) to be controlled is attached to the seat 13 of the automobile M.

The active control device is an electric control device 30
Is provided. The electric control device 30 includes a control unit 31 formed of a microcomputer, and has the adaptive control unit 40 described above as a part thereof. Further, the adaptive control unit 40 stores a data table RAM 41 that stores update data of the estimated transfer function. The control unit 31
This executes the “vibration removal control program” shown in FIG. The rotation pulse sensor 12 and the pickup acceleration sensor 14 are connected to the input side of the control unit 31. The actuator 23 of the engine mount 20 is connected to the output side of the control unit 31 via a power amplifier 32.

The present embodiment is directed to an automobile equipped with a four-cycle four-cylinder engine, and its main use rotational frequency is 600 to 6000 rpm, and the vibration frequency range of the secondary rotational component of interest is 20 to 200 Hz. is there. In this frequency range, the excitation for one cycle is performed in spots at intervals of 1 Hz, and the transfer function is measured. The time required for the measurement is a short time such that the occupant does not feel the excitation performed in a spot-like manner.
5 seconds or less. The range of the frequency used for one measurement is, for example, 20 to 22, 40 to 42, or 60.
The entire frequency range can be randomly selected, such as ~ 62 Hz.

The measurement interval is selected from several minutes to several days. For example, the interval of several minutes is adopted when it is desired to make the transfer function follow in a case where the time change is rapid such as a temperature change. 1 if the time change is not rapid
Wide intervals, such as every day or every few days, are employed. Further, as for the frequency used for measurement, a frequency different from the frequency at which the adaptive control is performed is selected. Thereby, appropriate excitation can be performed without disturbing the execution of the adaptive control. And
The selection of the frequency range, the selection of the measurement interval, the relationship with the frequency of the adaptive control, and the like are performed under the control of the control unit 31.

Next, the operation of the embodiment configured as described above will be described. The control unit 31 starts execution of the “vibration removal control program” in step 70 shown in FIG. 4, and in step 71, a measurement frequency range is selected. Here, a frequency range of 20 to 22 Hz is selected first. Next, at step 72, a measurement time interval is selected. Here, a one-day interval is selected, and the elapse of time is counted in the control unit 31. Next, it is determined whether or not the engine is operating (step 73).
Adaptive control is performed according to the adaptive control system shown in FIG. 2, and control for suppressing noise due to engine vibration is properly performed (step 74). Next, it is determined whether or not the measurement time of the transfer function has come (step 75). If the measurement time has not yet elapsed, the program returns to step 73 based on the determination of "NO". The process is similarly repeated.

At the measurement time, the measurement of the transfer function is started. That is, the excitation signal is output as a spot at 1 Hz intervals in the frequency range of 20 to 22 Hz (step 7).
6) The vibration of the actuator 23 is performed, and the vibration caused by the vibration is controlled by the pickup acceleration sensor 14 into the control unit 31.
And the value of the estimated transfer function is calculated based on the result (step 77). The calculated estimated transfer function data is rewritten with the estimated transfer function data stored in the data table RAM 41 (step 78). Since the measurement time of the estimated transfer function is as short as 0.5 seconds or less as described above and is a spot-like vibration, it is necessary to make the occupant aware of the vibration operation and give discomfort due to it. There is no. Then, the execution of the program is terminated in step 79, and the execution of the "vibration removal control program" is newly started from step 70.

As described above, in the present embodiment, the vibration by the signal of the frequency group selected at random may be applied to the vehicle body within a short time that the occupant does not feel while the engine of the vehicle is running. Therefore, the occupant does not feel discomfort due to the vibration caused by the vibration. Further, the estimated transfer function is measured at an arbitrary time interval during the operation of the engine, and the estimated transfer function data is updated based on the measured value, so that the estimated transfer function can be maintained in an appropriate state. , Appropriate vibration control can be performed. Also, by making the excitation frequency different from the excitation control frequency based on the adaptive filter, it is possible to perform excitation using a different frequency while performing excitation control appropriately. Thus, the measurement of the estimated transfer function can be accurately performed.

In each of the above embodiments, the rotation pulse signal of the engine is used.
From the vehicle position detection signals such as shift position and water temperature,
By obtaining optimal filters for each of these states, it is also possible to perform excitation control. In each of the above embodiments, a DXHS LMS filter is used as an adaptive filter. However, another adaptive filter such as a Filtered-X LMS filter may be used.

[Brief description of the drawings]

FIG. 1 is a schematic diagram schematically showing an active control device for removing vibration of a gasoline engine vehicle to which an embodiment of the present invention is applied.

FIG. 2 is a block diagram schematically showing the adaptive control system.

FIG. 3 is a partial cross-sectional view showing an engine mount with an actuator used in the active control device.

FIG. 4 is a flowchart of a “vibration removal control program” executed by a control unit.

FIG. 5 is a schematic diagram schematically showing a part of a vehicle to which an active control device is applied in a conventional example.

FIG. 6 is a block diagram schematically showing the adaptive control system.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Body, 11 ... Engine, 12 ... Rotation pulse sensor, 14 ... Pickup acceleration sensor, 20 ... Engine mount with an actuator, 21 ... Case, 22 ... Anti-vibration rubber, 23 ... Actuator, 30 ... Electric control device, 3
DESCRIPTION OF SYMBOLS 1 ... Control part, 32 ... Power amplifier, 40 ... Adaptive control part,
41: Data table RAM, 51: Vibration source, 52
... signal transmission system, 61 ... frequency determination unit, 62 ... adaptive filter W, 63 ... controlled object system (transfer function G), 64 ... controlled object system (estimated transfer function), 65 ... digital filter (DXHS)
LMS).

Claims (2)

[Claims] An input signal based on a periodic pulse signal from a vibration source of a vehicle is subjected to amplitude compensation and phase compensation by a filter coefficient which is a function of an amplitude compensation coefficient and a phase compensation coefficient of an adaptive filter. After processing using the transfer function of the controlled system, the processing signal based on the transfer function and the external force from the vibration source are added, and an error resulting from the addition and a predetermined estimation of the controlled system of the vehicle are performed. A digital filter sequentially updates filter coefficients of the adaptive filter based on an estimated transfer function processed signal obtained by subjecting the input signal to amplitude and phase processing using transfer function data, and performs excitation control of a vibrator based on the adaptive filter. An active control device that actively suppresses the vehicle body vibration by performing the above-described processing over a whole range of a predetermined frequency corresponding to the estimated transfer function data. According to signals of a plurality of frequency groups selected at random, during the operation of the engine of the vehicle, the vibrator is vibrated for a short time at an arbitrary time interval, a response due to the vibration is measured, and an estimated transfer function is calculated, An active control device characterized by sequentially updating estimated transfer function data defined in advance by the calculated estimated transfer function. 2. The active control device according to claim 1, wherein a frequency at which the vibration is performed is made different from a frequency at which the vibration control is performed based on the adaptive filter. apparatus.