JP2000027933A - Active engine mount device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an active engine mount device to execute constantly best vibration damping operation even when a secular change occurs to an engine mount and an engine foot, and maintain a riding sensation in a best state. SOLUTION: When, during excitation of an engine mount, an error signal outputted from an error sensor 19 exceeds a given value, it is decided by a C* update deciding part 31 that engine vibration is diverged and an update trigger is outputted to an adaptive filter 29 and a drive signal outputted from the adaptive filter 29 is suspended. Nextly, based on a vibration signal for vibration transmitted to an engine foot 2 through an engine mount 9 from an engine 7, the natural frequency of the vibration is extracted by a natural frequency detecting part 33. Based on this natural frequency, the transmission characteristic estimating value C* of the vibration transmitted to the engine mount 9 from the engine 7 is estimated by an estimating part 35 and updated and stored at a fixed filter 27.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an active engine for actively reducing engine vibration of an automobile or the like.
Related to a mounting device.

[0002]

2. Description of the Related Art Conventionally, as an active engine mounting apparatus, there is known an apparatus described in Japanese Patent Application Laid-Open No. 6-340228 shown in FIG. This active engine mount device is first equipped with an engine 7 when the vehicle is shipped.
The C * data representing the estimated value of the transfer characteristic is obtained by using the vibration when is not rotating. That is, sine wave data is generated by a sine wave generator 45 provided in the vibration controller 47, converted into a sine wave signal by the D / A converter 25, and the oscillating machine 10 provided in the engine mount 9 is operated. Excite. As a result, the engine mount 9 is vibrated.
Therefore, based on the sine wave signal and the error signal from the error sensor 19, the transfer characteristic estimated value C * data between the engine mount 9 and the engine foot 2 is obtained. C * data fixed filter 2
7

At the time of engine rotation, the adaptive filter 43 reads the transfer characteristic estimated value C * data read from the fixed filter 27 according to the engine speed and the A / D converter 23.
Drive data is generated based on the error signal from
The signal is converted into a drive signal by an / A converter 25 and supplied to a vibrator 10 provided in the engine mount 9. The vibration transmitted from the engine 7 to the engine foot 2 via the engine mount 9 can be minimized by the opposite-phase vibration generated by the vibration exciter 10 by the drive signal. As a result, there is an advantage that discomfort caused by engine vibration applied to the occupant during driving of the vehicle can be suppressed.

[0004]

By the way, in the conventional active engine mounting apparatus, the vibration suppression control by the adaptive filter 43 is stopped and the sine wave generation section 45 provided in the controller 47 generates the sine wave. The re-engine mount 9 is excited by the sine wave to obtain the transfer characteristic estimated value C * data. Also,
If the C * data is obtained during driving of the vehicle, the occupant may be uncomfortable due to the sine wave vibration. Therefore, the C * data obtained at the time of shipping the vehicle has been used.

[0005] However, components such as the engine mount 9 and the engine foot 2 are subject to aging due to oxidation, fatigue, and the like after the passage of time. As a result, when the transfer characteristic estimated value C * data obtained at the time of shipment of the vehicle is continuously used as it is, the vibration suppression control by the adaptive filter 43 is not performed to the best range, and the vibration suppression performance is deteriorated. There was such a problem.

[0006] The present invention has been made in view of the above,
It is an object of the present invention to provide an active engine mount device that can always perform the best vibration damping operation and maintain the best ride comfort even when the engine mount, the engine foot, and the like deteriorate over time. It is in.

[0007]

According to the first aspect of the present invention,
In order to solve the above-mentioned problem, fixed filter means for previously storing a transfer characteristic estimated value of vibration transmitted to an engine foot via an engine mount, and outputting the transfer characteristic estimated value, an engine and an engine mount Error vibration detection means for detecting an error vibration transmitted to the engine foot by synthesizing vibrations from the engine, an estimated value of a transmission characteristic from the fixed filter means, and an error signal based on the error signal from the error vibration detection means. An adaptive filter means for generating a drive signal having a phase opposite to that of the signal, and a vibration means for vibrating the engine mount in response to the applied drive signal, so as to minimize error vibration transmitted to the engine foot. An active engine mount device for attenuating the engine mount when the engine mount is vibrated. A vibration divergence determination unit that determines that the engine vibration is diverging when an error signal from the vibration detection unit exceeds a predetermined value, and a signal for stopping a drive signal output from the adaptive filter unit to the vibration unit. Stopping means, vibration detecting means for detecting vibration transmitted from the engine to the engine foot via the engine mount, and a vibration component for extracting a natural frequency of the vibration based on a vibration signal from the vibration detecting means Extraction means, based on the natural frequency extracted by the vibration component extraction means,
A transmission characteristic estimating means for estimating a transmission characteristic estimated value of vibration transmitted from the engine to the engine mount and updating and storing the estimated value in the fixed filter means.

[0008]

According to the first aspect of the present invention, when the error signal exceeds a predetermined value during the vibration of the engine mount, it is determined that the engine vibration is diverging, and the driving output from the adaptive filter is performed. Stop the signal. Next, a natural frequency of the vibration is extracted based on a vibration signal of the vibration transmitted from the engine to the engine foot via the engine mount, and transmitted from the engine to the engine mount based on the natural frequency. By estimating the transmission characteristic estimation value of the vibration and updating and storing the estimated value in the fixed filter, the transmission characteristic estimation value stored in the fixed filter can always be updated to the latest one. As a result, it is possible to always perform the best damping operation and maintain the best riding comfort irrespective of the deterioration of the engine mount, the engine foot and the like over time.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view showing a system configuration of an active engine mounting device according to one embodiment of the present invention. As shown in FIG. 1, below a frame 5 of a vehicle, wheels on which tires 3 are mounted are rotatably mounted on an engine foot cross member (hereinafter, referred to as an engine foot 2), and a cab of the vehicle body is provided above. 1 is provided.

An engine 7 is mounted on the engine foot 2, and an engine mount 9 is provided between the engine 7 and the engine foot 2. In addition, engine
The mount 9 is provided with a vibrator 10 for vibrating the engine mount 9 itself. The vibrator 10 is composed of an electromagnetic actuator that vibrates according to a drive signal from a D / A converter 25 described later. Further, an error sensor 19 is provided at a connection portion between the engine mount 9 and the engine foot 2 to detect an error vibration such as vibration applied to the engine foot 2 and acceleration and displacement as an error signal.

In the casing of the engine 7, there is provided a synchronization sensor 1 for generating a rotation speed synchronization signal synchronized with the rotation of the engine.
The synchronous sensor 11 calculates and outputs the number of revolutions from the detected frequency of the engine 7. Cab 1
A vibration controller 15 that attenuates the vibration transmitted from the engine 7 to the driver's seat or the like so as to be minimized and controls the vibrator 10 provided on the engine mount 9 to vibrate in the opposite phase. Is provided.

In FIG. 1, for convenience of explanation, a functional block diagram of the vibration controller 15 is shown outside the cab 1. The vibration controller 15 includes the A / D converter 2
1, 23, D / A converter 25, fixed filter 27, adaptive filter 29, C * update determination unit 31, C * update unit 39
It is composed of The vibration controller 15 has a CPU, a ROM, and a RAM inside, and is configured to control each unit based on a control program stored in the ROM.

The A / D converter 21 converts an analog signal representing the engine speed detected by the synchronous sensor 11 in synchronization with the engine vibration into engine speed data. A
The / D converter 23 converts an error signal output from the error sensor 19 into error data. D / A converter 25
Converts the drive data generated by the adaptive filter 29 into a drive signal and repeatedly supplies the drive signal to the vibrator 10 provided on the engine mount 9.

The fixed filter 27 incorporates C * data representing an estimated value of a transmission characteristic of an error vibration for each frequency band transmitted from the engine 7 to the engine foot 2 via the engine mount 9.

The adaptive filter 29 has a phase opposite to that of the error data from the A / D converter 23 based on the transfer characteristic estimated value C * data corresponding to the current engine speed output from the fixed filter 27. From the next point in time, the engine mount 9 is controlled so that the error signal input from the error sensor 19 via the A / D converter 23 is attenuated and minimized.
D / A converter 2 generates drive data for exciting
5 is output. The C * update determination unit 31 outputs the error sensor 1
The amplitude of the error signal input from 9 through the A / D converter 23 is compared with a threshold value K, and when the error signal is larger than the threshold value K, an update trigger is generated.

When an update trigger occurs, a C * updating unit 39 estimates a transmission characteristic C * based on engine vibration.
Is estimated, updated in the fixed filter 27, and recorded. C *
The updating unit 39 includes a natural frequency detecting unit 33, a C * estimating unit 35, and a memory unit 37, which will be described later.

First, the natural frequency detector 33 detects the natural frequency of the engine mount 9 based on an error signal input from the error sensor 19 via the A / D converter 23. The memory unit 37 stores the latest detected natural frequency. The C * estimating unit 35 determines the engine 7 based on the latest natural frequency read from the memory unit 37.
And a current transfer characteristic estimation value C * of the system including the engine mount 9 and the engine.

In general, when an object is free-vibrated by applying an external force under conditions that do not impose physical constraints, in addition to supporting the object at a support point, the object has rigidity, shape, and volume. It vibrates at the natural frequency based on the length. Accordingly, the engine mount 9 system is not an exception and has the natural frequency fa. As the engine mount 9 system deteriorates over time, its rigidity changes due to oxidation and hardening.
For example, the natural frequency fa changes to fx.

On the other hand, the transfer characteristic estimated value C * is a function of the natural frequency fa of the engine mount 9 system. That is, the transfer characteristic estimated value C * = F (fa). The initial natural frequency fa of the engine mount 9 system is
7 is known data, but the current natural frequency fx has not been stored in the memory unit 37 yet.

Next, the operation of the active engine mounting apparatus according to one embodiment of the present invention will be described with reference to the flowchart shown in FIG. First, during the operation in which the engine 7 is burning and rotating, the rotation speed synchronization signal from the synchronization sensor 11 is converted into engine rotation speed data by the A / D converter 21 and input to the fixed filter 27. The fixed filter 27 converts the transmission characteristic estimation value C * data of the vibration in each of the rotation speed bands already incorporated into the adaptive filter 29.
Output.

In step S10, the adaptive filter 29
Generates drive data based on the input transfer characteristic estimated value C * data of the rotation speed band and generates the D / A converter 25.
Then, the driving signal is converted into a driving signal, and the vibrator 10 provided on the engine mount 9 is vibrated. As a result, the vibration suppression control can be performed so that the vibration generated in the engine 7 is not transmitted to the vehicle interior by the adaptive filter 29. Here, the vibration of the engine 7 and the vibration of the engine mount 9 by the vibrator 10 are combined. In step S20, the combined vibration is measured by the error sensor 19.

The adaptive filter 29 converts the input transmission characteristics of the rotation speed band so that the error signal representing the vibration, acceleration, and displacement converted and input by the A / D converter 23 from the error sensor 19 is minimized. The estimated value C * data is increased or decreased, and the drive signal converted by the D / A converter 25 is supplied to the vibrator 10 in the engine mount 9 to perform adaptive control.
As a result, during the operation of the engine 7, the vibration of the engine 7 and the vibration of the shaker 10 are combined on the engine mount 7, and the vibration to the seat is attenuated to a minimum.

At the same time, the error signal from the error sensor 19 is converted into error data by the A / D converter 23,
* Sent to the update determination unit 31 and the natural frequency detection unit 33.
Therefore, in step S30, the C * update determination unit 31
Data such as the amplitude value of error data is constantly monitored.
It is determined whether or not a predetermined threshold value K has been exceeded, and it is determined whether or not the vibration is increasing and diverging. If the error data is equal to or smaller than the threshold value K, the vibration synthesized by the engine mount is normal, and the process returns to step S10 to repeat the processing. During this time, the adaptive filter 27 performs D / A conversion while increasing / decreasing the transfer characteristic estimated value C * in each rotation speed band so that the error data continuously converted by the A / D converter 23 from the error sensor 19 is minimized. The exciter 10 provided on the engine mount 9 is adaptively controlled via the exciter 25.

On the other hand, if the data such as the amplitude value of the error data exceeds the threshold value K while the C * update determination unit 31 is monitoring the error data, the process proceeds to step S40. The reason for exceeding the threshold value K is as follows. This is the case where the engine mount 9 is aged and deteriorated due to the use frequency and age of the vehicle, and the natural frequency fa of the engine 7 and the engine mount 9 system changes to, for example, fx due to oxidation and hardening. The estimated value C * = F (fa) of the vibration transfer characteristic in each frequency band for the engine mount 9 system incorporated in the fixed filter 27 at the time of production of the vehicle is:
This will deviate from the actual transfer characteristic estimated value C *. As a result, the vibration damping effect due to the anti-phase vibration is reduced, and the vibration passing through the engine mount 9 is increased and transmitted from the engine foot 2 to the seat.

Therefore, in step S40, the C * update determining section 31 generates an update trigger and sends it to the adaptive filter 29 and the C * update section 39. In step S50, the adaptive filter 29 stops generating drive data in response to the update trigger. As a result, the vibration control for the vibrator 10 provided in the engine mount 9 is temporarily stopped.

Then, in step S60, the engine 7
Is transmitted to the engine foot 2 via the engine mount 9 and measured by the error sensor 19. The vibration signal of the engine 7 measured by the error sensor 19 has various frequency components. Upon receiving the update trigger, the natural frequency detection unit 33 proceeds to step S
At 70, the vibration signal of the engine 7 is decomposed into each frequency component by the fast Fourier transform FFT, and the latest natural frequency fx transmitted from the engine 7 to the engine foot 2 via the engine mount is extracted. Next, the memory unit 37
Is updated to fx, and stored.

In step S80, the C * estimating unit 35 estimates the current transfer characteristic estimated value C * = F (fx) of the engine mount 9 system based on the latest natural frequency fx read from the memory unit 37. Is estimated. Then, in step S90, the estimated latest and current transfer characteristic estimated value C * is updated as the transfer characteristic estimated value C * of vibration in the frequency band of the engine mount 9 and is incorporated into the fixed filter 27. Returning to S10, the process is repeated.

As a result, the adaptive filter 29 reads the updated transfer characteristic estimated value C * data from the fixed filter 27, and reads the vibration exciter 10 provided on the engine mount 9.
Is applied, the vibration of the engine 7 is combined with the vibration of the engine mount 9, and only a minimum vibration is transmitted from the engine foot 2 to the seat, and the best ride comfort is maintained even after years.

As described above, when the error signal exceeds a predetermined value during the vibration of the engine mount, it is determined that the engine vibration is diverging. First, the drive signal to the vibrator provided on the engine mount is transmitted. Abort. Next, a natural frequency of the vibration is extracted based on a vibration signal of the vibration transmitted from the engine to the engine foot via the engine mount, and transmitted from the engine to the engine mount based on the natural frequency. By estimating the transmission characteristic estimation value of the vibration and updating and storing the estimated value in the fixed filter, the transmission characteristic estimation value stored in the fixed filter can always be updated to the latest one. As a result, it is possible to always perform the best damping operation and maintain the best riding comfort irrespective of the deterioration of the engine mount, the engine foot and the like over time.

In particular, when the vehicle is parked in a parking lot in a cold region in winter, when the engine mount 9 is frozen in the early morning, even when vibration occurs with the start of the engine, the engine mount can be mounted. 9 can be minimized. Further, when the engine mount 9 warms up and the natural frequency returns to the original value, the transfer characteristic estimated value C * data is re-corrected within a short period of time, so that the riding comfort can always be kept good.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of an active engine mounting device according to an embodiment of the present invention.

FIG. 2 is a flowchart for explaining the operation of the active engine mounting device according to one embodiment of the present invention.

FIG. 3 is a block diagram illustrating a configuration of a conventional active engine mounting device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cap 2 Engine foot 3 Tire 5 Frame 7 Engine 9 Engine mount 10 Vibrator 11 Synchronous sensor 15 Vibration controller 19 Error sensor 21, 23 A / D converter 27 Fixed filter 25 D / A converter 29 Adaptive filter 31 C * update determination unit 33 natural frequency detection unit 35 C * estimation unit 37 memory unit 39 C * update unit

Claims (1)

[Claims] 1. A fixed filter means for preliminarily storing a transmission characteristic estimation value of vibration transmitted to an engine foot via an engine mount and outputting the transmission characteristic estimation value, and a vibration from the engine and the engine mount. Error vibration detecting means for detecting an error vibration transmitted to the engine foot by combining the error signal, an error signal based on a transmission characteristic estimated value from the fixed filter means, and an error signal from the error vibration detecting means. Adaptive filter means for generating a drive signal having an opposite phase; and vibration means for vibrating an engine mount in accordance with the applied drive signal, wherein the error vibration transmitted to the engine foot is attenuated so as to be minimized. An active engine mount device, wherein the error vibration detection is performed when the engine mount is vibrated. A vibration divergence determination unit that determines that the engine vibration is diverging when an error signal from the unit exceeds a predetermined value; and a signal suspension unit that suspends a drive signal output from the adaptive filter unit to the vibration unit. Vibration detecting means for detecting vibration transmitted from the engine to the engine foot via the engine mount; and vibration component extracting means for extracting a natural frequency of the vibration based on a vibration signal from the vibration detecting means. A transmission characteristic estimating means for estimating a transmission characteristic estimation value of vibration transmitted from the engine to the engine mount based on the natural frequency extracted by the vibration component extracting means, and updating and storing the estimated value in the fixed filter means; An active engine mounting device comprising: