JPH10122296A - Active engine mount control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the frame vibration of a cab vibration input point surely, regardlees of the mode of a frame by installing an error sensor to a position for detecting the vibration of a cab mount part with a large vibration input to the cab. SOLUTION: Error sensors 9 like a vibration sensor, an acceleration sensor and a displacement sensor are installed on the frame part just below the front mount 3 of a cab 1. A/D converter 12 converts an engine rotation synchronous analog signal from an engine speed sensor 8 to a pulse and A/D converter 11 converts the error detection signal from the error sensor 9 to a digital signal. A fixed filter 13 amends the transmission characteristic of the output signal of the A/D converter 11. A adaptive filter 15 inputs the output signal of the fixed filter 13 and the output signal of the A/D converter 12 and controls adaptive an active engine mount 6 through D/A converter 14 so that the error detection signal from the A/D converter 12 become minimum.

Description

DETAILED DESCRIPTION OF THE INVENTION

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an active engine mount control device, and more particularly to an active engine mount control device for actively reducing engine noise of an automobile or the like.

[0001]

2. Description of the Related Art In recent years, the demand for comfort of automobiles and the like is high.
Low vibration and low noise engines are in progress. Vibration that is a problem in the engine idle rotation region is caused by engine roll resonance due to uneven combustion between cylinders or cycles,
So-called swaying vibration (about 7 to 15 Hz) and explosion 1
This is a pulsating vibration (approximately 20 to 35 Hz) that is caused mainly by torque fluctuation due to the next component. Further, in the high rotation region, there is a problem of the vibrating force due to the reciprocating inertial force of the engine motion system.

One of the elements to meet this demand is an improvement in an engine mount provided between an engine and a vehicle body. In order to address the above-mentioned problem, the engine mount must be mounted in an idling region of the engine. It is necessary that the damping of the low frequency vibration be large and the transmission rate in the high rotation region be small.

For this reason, rubber materials have been used for engine mounts for a long time. Recently, however, in order to improve low frequency vibration such as shake, a large damping force that cannot be obtained with rubber alone is generated. JP-A-6-340228
As disclosed in Japanese Patent Laid-Open Publication No. H10-115, an active actuator designed to reduce vibration over the entire engine rotation range by using an electromagnetic actuator unit.
Engine mount controls have been developed.

[0004]

When the above-described active engine mount control device is applied to a vehicle with a frame such as a truck, the active engine mount control device is connected to an engine 21 and a frame 22 as shown in FIG. An active engine mount 24 is installed between the engine mount bracket 23 and an error sensor 25 such as an acceleration sensor is disposed immediately below the active engine mount 24.

[0005] As shown in a side view in FIG. 10, an engine 5 is mounted on a frame 2, and a vehicle cab 1 corresponding to a vehicle compartment is mounted on a front cab 4 at four points on the frame 2.
The engine 5 is mounted on the frame 2 with a front engine mount 6 and a rear engine mount 7 and is mounted on a mount 3 and a rear cab mount 4.
The positions of the mounts 3, 4 and the engine mounts 6, 7 are shifted and different as shown in the figure.

For this reason, the vibration into the cabin is not
Directly from the cab mounts 3 and 4 above, the engine mounts 6 and 7 are separated from the cab mounts 3 and 4, and the base frame 2 has its own mode. As shown in FIG. 11 (2), the mounting points of the engine mounts 6 and 7 may be nodes of vibration of the frame 2, and the mounting points of the cab mounts 3 and 4 may be antinodes of the vibration. .

Accordingly, when the vibration control of the support point immediately below the mount is performed by actively controlling the engine mount, the mounting point B of the active engine mount is located at the antinode of the frame vibration as shown in FIG. In some cases, an apparently large effect can be obtained, but since the vibration level is small at the tip portion A of the cab and the influence on the vibration in the vehicle interior is small, the vehicle interior effect may be small or, conversely, deteriorated.

Further, when the mounting point B of the active engine mount is located at a node of the frame vibration as shown in FIG. 2B, almost no error detection signal is output, so that the active engine mount is controlled. Therefore, the vibration (belly) of the frame is transmitted as it is at the tip portion A of the cab, and the vibration reduction effect is not obtained or there is a small area.

Further, of the cab mounts 3 and 4,
The front cab mount 3 has a harder spring constant than the rear cab mount 4 and has a larger supporting load than the rear cab mount 4 because it restricts the movement of the cab 1.・ Mount 3
Are more easily transmitted to the cab 1.

Accordingly, the present invention provides an active engine mount control applicable to a vehicle having a frame structure such as a small truck, in which the positions of an engine mount and a cab mount mounted on the frame are different. It is intended to provide a device.

[0011]

To achieve the above object, an active engine mount control device according to the present invention comprises an active engine mount control device provided between an engine and a vehicle body frame and having a function of varying a spring constant. A mount, an error sensor provided at a position for detecting the vibration of the cab mount, a sensor for generating a signal synchronized with the rotation of the engine, and an engine rotation synchronization signal and an error detection signal from the error sensor. The active engine mount is detected by the rotation synchronization signal of the engine and the error detection signal using the transmission characteristic from the active engine mount, which is measured in advance, to the error sensor via the frame. A controller that performs adaptive control so that the signal is minimized.

That is, according to the present invention, the vibration of the cab mount portion having a large vibration input to the cab is detected from the position immediately below the conventional active engine mount (point B in FIG. 11). Location (Figure 1
Move to point A) of 1.

Then, the controller transmits the transmission between the active engine mount, the frame, and the front cab mount (error sensor) measured in advance using the engine rotation synchronization signal and the error detection signal from the error sensor. By using the characteristic, the active engine mount is adaptively controlled by the current engine rotation synchronization signal and the error detection signal so that the error detection signal is minimized.

As described above, the control target is set to the front cab
Since the vibration of the mount was minimized, FIG.
In the frame mode shown in (1), since the vibration level at the cab tip A is originally small, there is no problem even if the active engine mount is not substantially controlled, and the frame mode shown in FIG. In this case, since the vibration level at the cab tip A is large, the vibration can be suppressed by controlling the active engine mount.

Therefore, the frame vibration at the vibration input point of the cab can be reliably reduced regardless of the mode of the frame.
Thus, the vibration noise in the cab chamber can be reduced.

It is preferable that the above-mentioned error sensor is provided on a frame portion located directly below the front mount of the cab.

Further, the active engine mount can be constituted by an electromagnetic actuator section and a liquid operating section.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG.
1 is a schematic side view of an embodiment of an engine mount control device, in which 1 is a cab of a vehicle, 2 is a body frame for supporting the cab 1, and 3 is a front frame.
Cab mount, 4 for rear cab mount frame, 5 for engine, 6 and 7 for engine 5 and frame 2
, A front engine mount (active engine mount) and a rear engine mount, 8 an engine speed sensor for detecting an engine speed synchronization signal synchronized with the engine speed, 9 Are error sensors such as a vibration sensor, an acceleration sensor, and a displacement sensor provided in a frame portion of the cab 1 directly below the front mount 3.

Reference numeral 10 denotes a controller, which is an A / D converter 12 for converting an engine rotation synchronizing analog signal from the sensor 8 into a pulse, and an A / D converter for converting an error detection signal from the sensor 9 into a digital signal. Vessel 11 and A
A fixed filter 13 for correcting the transfer characteristic of the output signal of the / D converter 11, a D / A converter 14 for supplying a control signal to the active engine mount 6, and an output signal of the filter 13 and A / A A well-known method of inputting the output signal of the D converter 12 and adaptively controlling the active engine mount 6 via the D / A converter 14 so that the error detection signal from the A / D converter 12 is minimized. An adaptive filter 15 is provided. 16 is the controller 1
An amplifier (AMP) that amplifies a control signal from 0 to the active engine mount 6.

FIG. 2A is a plan view showing the embodiment shown in FIG. 1 with the cab 1 removed, and FIG. 2B is a view showing only the frame 2 from the side. It is shown.

As can be seen from FIG. 2, the front cab mounts 3 (3a, 3b) and the active engine mounts 6 (6a, 6b) are similar to those shown in FIGS. It is located separately at the tip A and the front engine part.

Since the error sensor 9 is provided at the front end A of the frame, the input from the front active engine mount, the input from the transmission 20 and the rear sensor at the point B shown in FIG. The sum of the inputs from the suspension part is observed by the error sensor 9.

FIG. 3 is a vector representation of the vibration waveform present at each of the points A to D shown in FIG. 2 on a real axis Re and an imaginary axis Im. A ′ represents points B to D observed at point A.
B ′ indicates a signal necessary for completely canceling the combined input observed at the position of the error sensor in the above-described conventional example.

Originally, if the vibration input into the cab is mainly from the point A, it is necessary to generate the cancel vector A '. In the present invention, this vector A' is generated. However, in the conventional example, the active
Since the vector B 'necessary for canceling the sensor detection signal immediately below the mounting point of the engine mount is generated, an apparently ideal cancellation is performed at the point B, but the vibration input system in the actual cab is used. On the other hand, when the cancel vector B ′ is used, a vector E is generated as a residual signal, and this is observed as deteriorating the vibration reduction effect.

FIG. 4 is a block diagram showing a control system by the controller 10 in FIG. 1. G is a transfer function to be controlled, that is, vibration of the engine 5 → active engine mount 6 → frame 2 → front cab. The transfer function up to the error sensor 9 (evaluation point) in the mount 3 is shown. C ^{* of the} fixed filter 13 is the actual transfer characteristic C and the transfer function G between the active engine mount 6 and the error sensor 9. And E indicates an error detection signal from the error sensor 9 (evaluation point).

The reason why the fixed filter 13 of the transfer characteristic estimated value C ^* is used as described above is that when the controller 10 controls the active engine mount 6, the distance from the active engine mount 6 to the error sensor 9 is controlled. Are separated, and the transmission characteristics such as the phase characteristics and transmission gain of the structure between them are not taken into account, so that the operation becomes unstable, the convergence time is delayed, and the control may be lost. .

Method for Determining Transfer Characteristic Estimated Value C ^* : Next, a method of incorporating the transfer characteristic estimated value C ^* will be described with reference to FIG.

(1) First, in the system shown in FIG. 5 (a), the vibration component from the engine 5 is not used, and instead, a sine wave generator 21 separately provided in the controller 10 and the engine rotation from the sensor 8 are used. A sine wave signal generated based on the synchronization signal is output, and the actuator of the active engine mount 6 is excited via the D / A converter 14.

The adaptive filter 22 (adaptive filter 1) is based on the sine wave signal and the error detection signal from the error sensor 9 installed immediately below the front cab mount 3.
5 may be used) are internal tap coefficients h (0) to h (n−
1) (hereinafter sometimes collectively referred to as H) is updated by the LMS algorithm as described above, and tap coefficients h (0) to h (n-1) that minimize the error detection signal are obtained. As the transfer characteristic estimated value C ^* .

FIG. 6 shows an example of a fixed filter incorporating the transfer characteristic estimated value C ^* at this time. The filter 13 fixes the measured tap coefficients h (0) to h (n-1). The only difference is that the adaptive filter 15 has

Since the present system is an adaptive system, the deviation of the transfer characteristic estimated value C ^* is absorbed by the adaptive filter 15, but if the deviation is large, it affects the control accuracy, so the following method is also devised.

(2) In an actual running state, a sine wave signal is generated based on a signal (primary explosion component) synchronized with the engine rotation from the sensor 8 and is used as a reference signal to which an actuator of the active engine mount 6 is applied. The reference signal at the time of vibration and the error detection signal from the error sensor
The transfer characteristic estimated value given to 2 is C _c ^* (this corresponds to the transfer characteristic estimated value C ^* in the above (1)).

On the other hand, the above-described
Reference signal and error detection signal from error sensor 9 at that time
Is given to the adaptive filter 22,
C_uc ^*And

At this time, the transfer characteristic estimated value C ^* of the fixed filter 13 actually incorporated in the controller 10 is C ^* = C _uc ^* -C _c ^* .

As a result, even if the frame on the ground side of the vibration of the active engine mount vibrates during actual running, an accurate transmission characteristic C ^* between the actual active engine mount and the frame can be obtained. The accuracy effect is improved.

Control operation of the controller: The controller 10 executes the actual control operation in this manner, but inputs the engine rotation information synchronized with the target engine vibration, for example, the primary component of the explosion from the sensor 8 as a reference signal. I do. The engine rotation information can be used as the reference signal because the engine vibration appears as a main component of the engine explosion and is synchronized with the engine rotation.

An error detection signal from the front cab mount 3 is detected by an error sensor 9. This error detection signal is obtained by calculating the difference between the actual engine vibration (corresponding to the transfer function G in FIG. 4) and the engine vibration output by driving the active engine mount 6 by the controller 10 (FIG. 4).
The adaptive filter 15 updates the tap coefficient H so that (corresponding to E) becomes minimum.

In this case, since the transfer characteristic estimation value C ^* is given in advance to the reference signal by the fixed filter 13,
The convergence of the adaptive control is performed quickly.

[0039]

As described above, according to the active engine mount control apparatus of the present invention, the error sensor is provided at the frame position for detecting the vibration of the cab mount, and the engine rotation synchronizing signal and the error sensor are provided. Active measurement previously measured using the error detection signal from
A controller for controlling the active engine mount using the transfer characteristic from the engine mount to the error sensor via the frame so that the error detection signal is minimized by the current engine rotation synchronization signal and the error detection signal. Is adapted to perform adaptive control, so that the effects shown in the experimental graphs of FIGS. 7 and 8 can be obtained.

That is, FIG. 7 shows the amplitude of the vibration in the frame portion immediately below the front cab mount where the error sensor for the engine speed is arranged. Active engine
It can be seen that the vibration is reduced as compared with the case where the error sensor is arranged on the mount.

FIG. 8 shows the amplitude of vibration on the floor in the cab chamber with respect to the engine speed. It can be seen that this case is also improved in comparison with the non-control example and the conventional example.

Further, if active control is performed based on the vibration of the front cab mount that transmits the largest amount of vibration from the frame to the cab, the cab vibration can be reduced more efficiently.

[Brief description of the drawings]

FIG. 1 is a schematic side view showing an embodiment of an active engine mount control device according to the present invention.

FIG. 2 is a schematic plan view showing a state where a cab is removed in an embodiment of the active engine mount control device according to the present invention.

FIG. 3 is a graph showing a vibration vector of each part in the active engine mount control device according to the present invention.

FIG. 4 is a block diagram showing a control principle of a controller used in the active engine mount control device according to the present invention.

FIG. 5 is a block diagram showing a measurement system for obtaining an estimated transfer characteristic used in the active engine mount control device according to the present invention.

FIG. 6 is a block diagram of a fixed filter incorporating an active engine mount transfer characteristic estimation value in the active engine mount control device according to the present invention.

FIG. 7 is a graph comparing the vibration level immediately below the cab mount in the active engine mount control device according to the present invention with that of the conventional example.

FIG. 8 is a graph comparing the vibration level on the cab cabin floor in the active engine mount control device according to the present invention with that of the conventional example.

FIG. 9 is a schematic side view showing an active engine mount in a conventional example.

FIG. 10 is a schematic side view showing a relationship between a cab mount and an engine mount.

FIG. 11 is a schematic side view showing a relationship between a vibration mode of a vehicle body frame and a control effect.

[Explanation of symbols]

 Reference Signs List 1 cab 2 frame 3 front cab mount 4 rear cab mount 5 engine 6 active engine mount 7 rear engine mount 8 engine speed sensor 9 error sensor 10 controller 13 fixed filter 15 adaptive filter Same in the figure. Symbols indicate the same or corresponding parts.

Claims (3)

[Claims] An active engine mount provided between an engine and a vehicle body frame and having a function of varying a spring constant, an error sensor provided at a position for detecting vibration of a cab mount, and an engine rotation. A sensor that generates a synchronized signal, and a transmission characteristic from the active engine mount to the error sensor via the frame, which is measured in advance using the engine rotation synchronization signal and an error detection signal from the error sensor. A controller that adaptively controls the active engine mount using a rotation synchronization signal of the current engine and an error detection signal so that the error detection signal is minimized by using the controller. Mount control device. 2. The active engine mount control device according to claim 1, wherein said error sensor is provided on a frame portion located immediately below a front mount of said cab. 3. The method according to claim 1, wherein
An active engine mount control device, wherein the engine mount includes an electromagnetic actuator section and a liquid operating section.