JP2000002292A - Vehicular positive vibration control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect abnormality of a sensor which senses residual vibration transmitted to a vehicular side with high accuracy and a low cost. SOLUTION: An engine speed sensed signal N is read in a step 201 immediately after charging a power, then it is shifted to a step 202. When the value N is not less than Nth, execution after a step 203 is omitted. When the value N is less than Nth a residual vibration signal (e) is read in the step 203. In a step 204, whether a specified time has passed or not is determined. When the answer is NO, it is returned to the step 203 where the residual vibration signal (e) is read again. When the answer in the step 204 is YES, it is shifted to a step 205 where a maximum amplitude Amax of the read residual vibration signal (e) is retrieved. In a step 206, when the value Amax is not less than eth, it is determined that a load sensor is normally operated. When the value Amax is less than eth, failure occurrence at the load sensor is determined. Then it is shifted to a step 207.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an active vibration for a vehicle in which vibration transmitted from the engine to the vehicle body is reduced by control vibration generated by an active engine mount interposed between the engine and the vehicle body. More particularly, the present invention relates to a control device that can detect an abnormality of a sensor that detects residual vibration transmitted to a vehicle body with higher accuracy and at lower cost.

[0002]

2. Description of the Related Art A conventional technique of this kind is disclosed in, for example, Japanese Patent Application Laid-Open No. 4-302729.
That is, the above publication discloses a liquid-filled active engine mount capable of generating an active supporting force. In such an active engine mount, a relatively low frequency such as an engine shake is used. As for the vibration, like the passive liquid-filled engine mount, the vibration transmitted from the vibrating body to the support is attenuated using the resonance of the liquid flowing between the two liquid chambers, while the idle For relatively high-frequency vibrations that are higher than vibration, the movable member that forms a part of the partition of the liquid chamber is actively displaced, and the pressure change in the liquid chamber is applied to the expansion spring of the support elastic body to actively A supporting force is generated to cancel the vibration.

In the apparatus disclosed in the above publication, the active vibration is detected by detecting a residual vibration transmitted to the vehicle body and executing an adaptive algorithm such as an LMS algorithm using the residual vibration as an evaluation function. A drive signal for driving the engine mount was generated.

[0004]

In the case of the active engine mount described above, the vibration transmitted from the power unit to the vehicle body through the active engine mount is offset to some extent by the active support force. This can contribute to reduction of vibration on the vehicle body side.

On the other hand, when the above-described active vibration control device for a vehicle is actually mounted on a vehicle, an abnormality in a sensor for detecting residual vibration transmitted to the vehicle body side, particularly, an abnormality between the sensor and the controller. If there is no means to detect disconnection or short-circuit abnormalities in the wiring connecting the vehicle, when such abnormalities occur, the control vibration generated by the active engine mount will actually exacerbate the vehicle vibration and cause discomfort to the occupants. There is a possibility to give. For this reason, there has been a demand for the development of a technique capable of detecting the abnormality of the sensor for detecting the residual vibration with high accuracy and at low cost.

The present invention has been made in view of such problems to be solved, and is an active vibration control system for a vehicle capable of detecting an abnormality of a sensor for detecting residual vibration with high accuracy and at low cost. It is intended to provide a device.

[0007]

In order to achieve the above object, an invention according to claim 1 is an active type which is interposed between an engine and a vehicle body and is capable of generating control vibration which interferes with vibration generated by the engine. An engine mount, a residual vibration detecting unit that detects the vibration after the interference and outputs the residual vibration signal, and control for driving and controlling the active engine mount so as to reduce the vibration of the vehicle body based on the residual vibration signal. Means for detecting the engine speed, based on the residual vibration signal and the engine speed immediately after power is supplied to the control means. Abnormality detecting means for detecting an abnormality of the residual vibration detecting means.

According to a second aspect of the present invention, in the active vibration control device for a vehicle according to the first aspect of the present invention, the control means detects a generation state of the vibration and outputs a reference signal as a reference signal. Means, an adaptive digital filter having variable filter coefficients, filter coefficient updating means for updating the filter coefficients of the adaptive digital filter based on the residual vibration signal and the reference signal and according to an adaptive algorithm, and the reference signal and the adaptive digital filter Drive signal generating means for generating and outputting a drive signal for driving the active engine mount based on the above.

According to a third aspect of the present invention, in the active vibration control device for a vehicle according to the first or second aspect, the abnormality detecting means is configured such that the engine speed is less than a predetermined speed. When the magnitude of the residual vibration signal immediately after the power is turned on to the control means is smaller than a predetermined threshold value, it is determined that the residual vibration detection means is abnormal. did.

According to a fourth aspect of the present invention, in the active vibration control device for a vehicle according to the third aspect of the present invention, the predetermined rotational speed is a rotational speed at which the engine can be determined to be in a cranking state. And

According to a fifth aspect of the present invention, in the active vibration control device for a vehicle according to the first or second aspect, the abnormality detecting means includes a control unit for controlling the abnormality immediately after power is supplied to the control means. When the magnitude of the residual vibration signal is less than a predetermined threshold value, the threshold value is set based on the engine speed, and a determination unit that determines that an abnormality has occurred in the residual vibration detection unit. Threshold setting means.

According to a sixth aspect of the present invention, in the active vibration control device for a vehicle according to the fifth aspect of the present invention, the threshold value setting means is configured such that when the engine speed is high, the threshold value setting means is lower than when the engine speed is low. Thus, the threshold value is set small.

In the invention according to the first aspect, immediately after the power is turned on to the control means, the vibration reduction control by the control means has just started, so that the drive of the active engine mount is controlled and the control vibration is reduced. Even if it occurs, the vibration is not reduced or the vibration reduction margin is small. Then, since the control means appropriately controls the drive of the active engine mount based on the residual vibration signal, after a while, the engine vibration is offset by the control vibration,
Residual vibration is reduced.

In particular, in the case where the filter coefficients of the adaptive digital filter are successively updated according to the adaptive algorithm as in the second aspect of the present invention, the condition that the filter coefficients of the adaptive digital filter converge to the optimum value is obtained. Therefore, the level of the residual vibration is high immediately after the power is turned on to the control means, and after a while the filter coefficient of the adaptive digital filter is updated to some extent, the level of the residual vibration is reduced. Will begin to fall.

Therefore, if the residual vibration signal is not at a certain level, for example, based on the residual vibration signal immediately after the power is turned on to the control means, it is possible that the residual vibration detecting means has an abnormality. Is high.

On the other hand, the control means is actually realized by a microcomputer or an electronic circuit, and the timing when such control means is turned on is mainly immediately after the ignition is turned on. However, when the power supply voltage supplied from the battery is momentarily lowered due to a momentary connection failure or the like, the microcomputer may be reset. May be indistinguishable from In other words, from the point of view of the microcomputer, immediately after the instantaneous drop of the power supply, it is the same as immediately after the power is turned on, so that it is determined that the control means has been turned on even though the engine has not been started. Then, there is a possibility that the abnormality determination processing of the residual vibration detecting means is executed based on the residual vibration signal at that time.

Then, when the engine speed is high, there may be a case where the abnormality determination processing of the residual vibration detecting means is executed. However, the vibration generated in the engine is higher when the engine speed is higher than when it is lower. Low and therefore
If the microcomputer is reset due to a momentary drop in power when the engine speed is high, it is possible that the level of the residual vibration signal is low and that the residual vibration detection means is erroneously determined to be abnormal. There is.

Therefore, as in the first aspect of the present invention, if the abnormality detecting means executes the abnormality detecting process based on both the residual vibration signal immediately after the control means is turned on and the engine speed, The possibility of misjudgment can be reduced.

Further, a sensor for detecting the engine speed is provided in a normal vehicle, and the residual vibration signal is a signal which has already been read into the microcomputer. Therefore, it is not necessary to provide a new sensor or the like. Therefore, there is no significant cost increase.

As a specific configuration of the abnormality detecting means, the following can be considered. In other words, the abnormality detecting means according to the third aspect of the present invention basically provides the residual vibration detecting means when the magnitude of the residual vibration signal immediately after the power is supplied to the control means is smaller than a predetermined threshold value. It is determined that an abnormality has occurred, but if the engine speed is not lower than the predetermined speed, the residual vibration signal may be lower than the predetermined threshold even if the magnitude of the residual vibration signal is smaller than the predetermined threshold value. Since it is not determined that an abnormality has occurred in the vibration detection means, the possibility of erroneous detection is reduced accordingly.

In this case, it is desirable that the predetermined engine speed used for the determination is a speed that can determine whether the engine is in a cranking state, as in the invention according to claim 4. In other words, since the engine speed in the cranking state is lower than the engine speed after the start of the engine is completed, it is necessary to determine whether such an engine speed is to be subjected to abnormality determination processing in Sakai. Thus, the possibility of erroneous detection can be reduced more reliably. The specific value of the predetermined rotation speed may be appropriately determined based on the vehicle specifications, but a value of, for example, about 1000 rpm is applicable.

On the other hand, the abnormality detecting means according to the fifth aspect of the present invention basically provides a method for detecting a residual vibration when the magnitude of the residual vibration signal immediately after the power is turned on to the control means is smaller than a predetermined threshold value. It is determined that an abnormality has occurred in the vibration detection means, and the threshold value of the magnitude of the residual vibration signal used for the determination is variable according to the engine speed. That is, since the magnitude of the vibration generated in the engine is substantially determined by the engine speed, the possibility of erroneous detection can be reduced by determining the threshold value according to the engine speed.

Since the vibration generated in the engine generally tends to decrease when the engine speed is high, if the threshold value is set as in the invention according to claim 6,
The possibility of erroneous detection can be reduced more reliably.

[0024]

According to the present invention, the abnormality detection of the residual vibration detecting means is performed based on the residual vibration signal immediately after the control means is turned on and the engine speed. Has an effect that the abnormality of can be detected with high accuracy and at low cost.

In particular, the inventions according to claims 3 to 6 have an effect that the possibility of erroneous detection can be reduced more reliably.

[0026]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 6 show the first embodiment of the present invention, and FIG. 1 is a schematic side view of a vehicle to which the active vibration control device for a vehicle according to the present invention is applied.

First, the structure will be described. An engine 17 mounted horizontally is supported by a vehicle body 18 composed of a suspension member and the like via an active engine mount 20 arranged rearward in the vehicle longitudinal direction. . In addition,
Actually, a plurality of engine mounts that generate a passive supporting force according to the relative displacement between the engine 17 and the vehicle body 18 are interposed between the engine 17 and the vehicle body 18 in addition to the active engine mount 20. . As a passive engine mount, for example, a normal engine mount that supports a load with a rubber-like elastic body, or a known fluid-filled mount in which a fluid is sealed inside a rubber-like elastic body so that a damping force can be generated. An insulator or the like can be applied.

FIG. 2 is a plan view showing the upper structure of an active engine mount 20 connected to the engine 17 via a bracket (not shown) fixed to the engine 17. The two projecting connection bolts 30a are inserted from below into the insertion holes of the bracket described above, and nuts are screwed into the engine 17 so that the engine 17 is rotated.
Is fixed at the upper end. Reference numeral 60 denotes a rebound restricting member. The rebound restricting member 60 extends perpendicularly to a line connecting the two connecting bolts 30a and extends above the engine-side connecting member 30 in an arch shape. It is fixed to the case 43 and is located above the rebound stopper 31 made of a rubber elastic body fixed to the upper surface of the engine side connecting member 30.

FIG. 3 shows an internal structure of the active engine mount 20 shown in a sectional view taken in the direction of the arrow in FIG.
Of the A-A arrow sectional along a line connecting the two connecting bolts 30a, the axis of FIG. 3 (hereinafter, referred to as the mounting shaft) P ₁
Are shown on the right side as boundaries, and the two connecting bolts 30 of FIG.
The direction taken along line B-B cross sectional view perpendicular to the line connecting the a, are shown to the right of the mounting shaft P ₁ in FIG. 3 as the boundary.

In the active engine mount 20, mounting parts such as an outer cylinder 34, an intermediate cylinder 36, an orifice constituting member 37, and a support elastic body 32 are built in an apparatus case 43, and a fluid chamber 84 is provided below these mounting parts. The movable member 78 elastically supported while forming a part of the partition
This is a device incorporating an electromagnetic actuator 52 for displacing in the direction in which the volume of the vehicle changes, and a load sensor 64 for detecting a vibration state of a vehicle body member (not shown). The member 30 has a lower peripheral edge portion 30g formed with roundness,
The first hole 30c is formed at a position along the mounting shaft P _1. The connection bolt 30a fitted into the engine connection member 30 from below and facing upward has a head 30d protruding from the lower surface of the engine connection member 30. Here, the outer peripheral edge of the head 30d is formed to be rounded.

A hollow cylindrical body 30b having an inverted trapezoidal cross section is fixed to the lower surface of the engine side connecting member 30.
This hollow cylinder 30b, with a second hole 30e at a position close to the connecting bolts 30a are formed, the third hole 30f is formed on the lower surface along the mounting axis P _1. No hole is formed in the hollow cylinder 30b at a position separated from the connection bolt 30a.

A rubber support elastic body 32 is provided on the lower surface of the engine-side connecting member 30 so as to cover the inside of the hollow cylindrical body 30b and the lower side of the engine-side connecting member 30.
Are fixed by vulcanization adhesion.

That is, the support elastic body 32 is a rubber elastic body whose diameter is increased downward from the engine-side connecting member 30 side, and has a hollow section 32 having a mountain-shaped cross section on its inner surface.
a, but the outer peripheral surface of the support elastic body 32 at a portion apart from the connecting bolt 30a is formed on the rebound stopper 31 while covering the outer peripheral portion of the engine side connecting member 30 as shown on the left side of FIG. It is continuous. On the other hand, as shown in the right side of FIG. 3, the support elastic body 32 that is close to the connection bolt 30a has a covering portion 32b that covers the entire area of the head 30d of the connection bolt 30a, and the head 30d
Has a shape that is largely recessed inward (hereinafter, referred to as a recessed outer peripheral portion indicated by reference numeral 32c). The inner surface of the support elastic body 32 facing the concave outer peripheral portion 32c while forming the above-described hollow portion 32a is also formed into a shape which is greatly expanded inward (hereinafter, reference numeral 32d).
(Referred to as a bulge inner peripheral portion). And connecting bolt 3
The thickness of the portion of the support elastic body 32 close to 0a is substantially the same as the thickness of the portion away from the connecting bolt 30a by providing the bulging inner peripheral portion 32d facing the concave outer peripheral portion 32c. Is set to

[0034] Then, the lower end portion of the resilient support member 32 which is a thin shape, the inner peripheral surface of the intermediate cylinder member 36 which mounts shaft P ₁ is oriented vibrator support direction to the hollow cylinder 30b coaxially by vulcanization bonding bond are doing.

The intermediate cylinder 36 is a member in which a small-diameter cylinder 36c is continuously formed between an upper cylinder 36a and a lower cylinder 36b having the same outer diameter, and has an annular recess on the outer periphery. Although not shown, an opening is formed in the small-diameter cylindrical portion 36c, and the inside and the outside of the intermediate cylindrical body 36 communicate with each other through this opening.

An outer cylinder 34 is fitted on the outside of the intermediate cylinder 36, and the outer cylinder 34 has the same inner diameter as the outer diameter of the upper cylinder 36a and the lower cylinder 36b of the intermediate cylinder 36. age,
It is a cylindrical member whose axial length is set to the same size as the intermediate cylinder 36. An opening 34a is formed in the outer cylinder 34, and an outer periphery of a diaphragm 42 made of a rubber thin film elastic body is coupled to an opening edge of the opening 34a so as to close the opening 34a. It bulges toward the inside of the outer cylinder 34.

When the outer cylinder 34 having the above structure is fitted around the intermediate cylinder 36 so as to surround the annular recess, an annular space is defined in the circumferential direction between the outer cylinder 34 and the intermediate cylinder 36, and the annular space is formed. The diaphragm 42 is disposed in the space in a swelled state. A tubular orifice component member 37 is fitted inside the intermediate tubular body 36.

The orifice constituting member 37 has a minimum diameter cylindrical portion 3 formed to have a smaller diameter than the small diameter cylindrical portion 36c of the intermediate cylindrical body 36.
An upper annular portion 37b and a lower annular portion 37c are formed radially outward at upper and lower ends of the minimum diameter cylindrical portion 37a, and the minimum diameter cylindrical portion 37a, the upper and lower annular portions 37b are formed. , 37c and an intermediate space between the intermediate cylinder 36. In addition, the minimum diameter cylindrical portion 3
A second opening 37d is formed in a part of 7a. Here, the upper annular portion 37b is located below the support elastic body 32, but as shown on the right side of FIG.
upper annular portion 37b ₁ which is located below the resilient support member 32 in proximity to a is provided with a recess to form a thin wall thickness, a position away from the bulge in the peripheral portion 32d of the elastic support member 32 Facing each other.

The device case 43 has an upper end caulking portion 43a having a circular opening having a diameter smaller than the outer diameter of the upper end cylindrical portion 36a at the upper end thereof, and a case body continuous with the upper end caulking portion 43a. Is a cylindrical member (the lower end opening is indicated by a broken line in FIG. 2) having the same inner diameter as the outer diameter of the outer cylinder 34 and continuing to the lower end opening. By caulking the lower end opening portion inward in the radial direction after the completion of assembling, the caulked portion shown by the solid line in FIG. 2 is formed.

The support elastic body 32, the intermediate cylinder 36,
The outer cylinder 34 in which the orifice constituting member 37 and the diaphragm 42 are integrated is fitted into the inside of the apparatus case 43 from the lower end opening thereof, and the outer cylinder 34 is attached to the lower surface of the upper end caulking part 43a.
When the upper ends of the intermediate cylinders 36 are brought into contact with each other, they are arranged at the upper part in the device case 43. At this time, an air chamber 42c is defined in a portion surrounded by the inner peripheral surface of the device case 43 and the diaphragm 42, and an air hole 43a is formed at a position facing the air chamber 42c. 43
The air chamber 42c communicates with the atmosphere via a.

A cylindrical spacer 70 is fitted into a lower portion of the device case 43, and a movable member 78 is disposed in an upper portion of the spacer 70.
An electromagnetic actuator 52 is arranged at a lower part in the area “0”. The spacer 70 includes a cylindrical upper cylindrical body 70a,
It is composed of a cylindrical lower cylinder 70b and a substantially cylindrical diaphragm 70c made of a rubber thin film elastic body that is vulcanized and bonded between upper and lower ends of these cylinders.

The electromagnetic actuator 52 has an external cylindrical yoke 52a, an annular exciting coil 52b disposed on the upper end side of the yoke 52a, and a magnetic pole fixed vertically to the center of the upper surface of the yoke 52a. Permanent magnet 52c
It is composed of The yoke 52a has an annular first yoke member 53a and a permanent magnet 5 in a central cylindrical portion.
2c is fixed to the second yoke member 53b.

The upper and lower cylinders 70a, 70b
The intervening diaphragm 70c bulges toward a concave portion 52d formed on the outer periphery of the yoke 52a. In addition, a load sensor 64 is interposed between the lower surface of the yoke 52a and the lid member 62 having the vehicle body side connection bolts 60 in order to detect residual vibration required for vibration reduction control. As the load sensor 64, a piezoelectric element, a magnetostrictive element, a strain gauge, or the like can be applied. As shown in FIG. 1, the detection result of this sensor is supplied to the controller 25 as a residual vibration signal e. I have.

On the other hand, above the electromagnetic actuator 52, a seal ring 72 for fixing a seal member, a support ring 74 for supporting the outer peripheral portion of a leaf spring 82 described below from below at a free end, and a permanent Magnet 52c
And a gap holding ring 76 for setting a gap H between the movable members 78. The outer diameters of the seal ring 72, the support ring 74, and the gap holding ring 76 are set to the same dimensions as the inner diameter of the upper cylinder 70a of the spacer 70 described above, and the upper cylinder projecting upward from the yoke 52a. A seal ring 72 in the body 70a;
All of the support ring 74 and the gap retaining ring 76 are fitted inside. A movable member 78 is arranged inside the seal ring 72, the support ring 74, and the gap holding ring 76 so as to be vertically displaceable.

The movable member 78 is a member composed of a partition wall forming member 78A having a disk shape in appearance and a magnetic path forming member 78B formed in a disk shape larger in diameter than the partition wall forming member 78A. A bolt hole 80a is formed in the axial center of the partition wall forming member 78A located farther from the electromagnetic actuator 52, and a magnetic path forming member 78B close to the electromagnetic actuator 52 is formed.
The partition wall forming member 78A and the magnetic path forming member 78B are integrally connected by screwing a movable member bolt 80 that passes through the bolt hole 80a into the bolt hole 80a.

Partition wall forming member 78A and magnetic path forming member 78
A ring-shaped continuous constriction 79 is defined between B, and a plate spring 82 for elastically supporting the movable member 78 is accommodated in the constriction 79. That is, the leaf spring 82 is a disk-shaped member having a hole formed in the center, and the free end of the inner periphery of the leaf spring 82 is supported from below the rear center of the partition wall forming member 78A. 82 is supported at its free end from below by a spring support portion 74a of a support ring 74, whereby the movable member 78 is
3 is elastically supported via a leaf spring 82.

The partition wall forming member 78A is formed by reducing the thickness of the partition wall portion 80c facing the fluid chamber 84,
A member formed with an annular rib 80b protruding upward from the outer periphery of the member. A fluid chamber 84 is formed by the upper surface of the partition wall forming member 78A, the lower surface of the support elastic body 32, and the inner peripheral surface of the orifice constituting member 37, and the fluid is sealed in the fluid chamber 84.

In order to prevent leakage of fluid from the fluid chamber 84 to the constricted portion 79 containing the leaf spring 82,
A ring-shaped seal member 86 made of a rubber-like elastic body is fixed between the outer periphery of the partition wall forming member 78A and the inner periphery of the seal ring 72. The elastic deformation of the seal member 86 causes the seal ring 72, The relative displacement of the movable member 78 in the vertical direction with respect to the device case 43 is allowed.

Next, the vibration input damping action of the active engine mount 20 of this embodiment will be briefly described. In the active engine mount 20 of the present embodiment, the hollow portion 32a of the support elastic body 32 communicates with the axial center space of the orifice member 37, and the axial center space of the orifice member 37 and the orifice member 37 and the intermediate cylindrical body. 36, the annular space communicates through a second opening 37d, and the annular space and the space in which the diaphragm 42 bulges communicate through an opening formed in the intermediate cylinder 36. From the hollow portion 32a of the supporting elastic body 32,
A fluid such as ethylene glycol is sealed in the communication path to the space where the bulges.

If the communication passage from the hollow portion 32a of the support elastic body 32 to the annular space between the orifice constituting member 37 and the intermediate cylinder 36 is the main fluid chamber 84, the intermediate cylinder 3
A fluid resonance system is formed in which the vicinity of the opening formed in 6 is an orifice, and the region surrounded by the diaphragm 42 facing the opening is a sub-fluid chamber. The characteristics of this fluid resonance system, that is, the mass of the fluid in the orifice,
The characteristic determined by the expansion direction spring of the support elastic body 32 and the expansion direction spring of the diaphragm 42 is that when the engine vibration is generated while the vehicle is stopped, that is, when the engine mount 20 is at 20 to 30 Hz.
A and 20B are adjusted so as to exhibit a high dynamic spring constant and a high damping force when vibrated.

On the other hand, the exciting coil 52b of the electromagnetic actuator 52 generates a predetermined electromagnetic force according to a drive signal y which is a current supplied from the controller 25 through, for example, a harness. Controller 25
Is a microcomputer, necessary interface circuit, A / D converter, D / A converter, amplifier, ROM, R
A drive signal y for the active engine mount 20 is generated such that an active support force that is configured to include a storage medium such as an AM or the like and reduces vibration generated in the engine 17 is generated in the active engine mount 20. Output.

As described above, the load sensor 64 is built in the active engine mount 20 and
8 is detected in the form of a load and output as a residual vibration signal e, and the residual vibration signal e is used as a signal representing the vibration after the interference by the controller 2 through, for example, a harness.
5.

Here, for example, in the case of a reciprocating four-cylinder engine, the engine vibration of the engine rotation secondary component is generated by
The main reason is that the vibration is transmitted to the engine 8 and, if the drive signal y is generated and output in synchronization with the secondary component of the engine rotation, the vibration on the vehicle body side can be reduced. Therefore, in the present embodiment, an impulse signal synchronized with the rotation of the crankshaft of the engine 17 (for example, in the case of a reciprocating four-cylinder engine, one for every 180 ° rotation of the crankshaft) is generated, and the reference signal x Pulse signal generator 19 which outputs as
Is provided, and the reference signal x is supplied to the controller 25.

Then, based on the supplied residual vibration signal e and reference signal x, the controller 25 performs a synchronous Filtered-X LMS which is one of adaptive algorithms.
By executing the algorithm, a drive signal y for the active engine mount 20 is calculated, and the drive signal y is output to the active engine mount 20.

Specifically, the controller 25 has an adaptive digital filter W having a variable filter coefficient W _i (i = 0, 1, 2,..., I-1: I is the number of taps).
The filter coefficient W _i of the adaptive digital filter W is sequentially output as the drive signal y at a predetermined sampling clock interval from the time when the latest reference signal x is input, while the reference signal x and the residual vibration signal e are output. A process for appropriately updating the filter coefficient W _i of the adaptive digital filter W based on this is executed.

However, in this embodiment, the synchronous Fi
The following equation (1) is used as an evaluation function in the iterated-X LMS algorithm. Jm = {e (n)} ² + β {y (n)} ² (1) That is, in the LMS algorithm, the evaluation function Jm
Since the filter coefficient W _i is updated in a direction in which is smaller, the filter coefficient W _i becomes smaller as the square value of the residual vibration signal e becomes smaller, as is clear from the content of the right side of the above equation (1). , The value obtained by multiplying the square value of the drive signal y by β becomes smaller. Β is a coefficient called a divergence suppression coefficient. As the divergence suppression coefficient β increases, the drive signal y tends to decrease. That is, the divergence suppression coefficient β has an effect of suppressing the divergence of the control.

When the convergence coefficient is α and an update equation for the filter coefficient W _i is obtained based on the evaluation function Jm expressed by the above equation (1), the following equation (2) is obtained. _{W i (n + 1) =} W i (n) + 2αR T e (n) -2βαy (n) ...... (2) Therefore, this (2) a new convergence factor to "2α" in the formula α
And then, if the a new divergence suppression factor β "2βα" update equation of the filter coefficients W _i of the adaptive digital filter W is as the following equation (3).

[0058] _{W i (n + 1) =} W i (n) + αR T e (n) -βy (n) ...... (3) here, (n), terms that stick is (n + 1), the sampling time n, n + 1 ,, And.
The update reference signal R ^T is theoretically the reference signal x
Is a value obtained by performing a filtering process using a transfer function filter C ＾ that models a transfer function C between the electromagnetic actuator 52 and the load sensor 64 of the active engine mount 20. The magnitude of the reference signal x is “1”. Therefore, when the impulse responses of the transfer function filter C # are successively generated in synchronization with the reference signal x, the impulse responses coincide with the sum of the impulse response waveforms at the sampling time n.

Further, theoretically, the reference signal x is filtered by the adaptive digital filter W to generate the drive signal y. However, since the magnitude of the reference signal x is "1", the filter coefficient W _{Even if i} is sequentially output as the drive signal y, the result is the same as when the result of the filter processing is set as the drive signal y.

Further, the controller 25 performs the vibration reduction processing using the adaptive digital filter W as described above, and immediately after the power is turned on, based on the residual vibration signal e and the engine speed, An abnormality detection process for detecting whether a disconnection abnormality, a short circuit abnormality, or the like has occurred in the load sensor 64 has been performed.

That is, the controller 25 is supplied with an engine speed detection signal N from the engine speed sensor 28. Based on the engine speed detection signal N immediately after the power is turned on, the engine speed is determined. N is equal to or a predetermined rotational speed N _th or more, the engine speed N
Is less than the predetermined rotation speed N _th and the maximum amplitude A _max of the residual vibration signal e immediately after the power is turned on is also less than the predetermined threshold value e _th , an abnormality has occurred in the load sensor 64. Is to be determined. The term “immediately after the power is turned on” means a period from when the power is turned on to the controller 25 until a predetermined time elapses. The predetermined time is a period from when the ignition is turned on to when the cranking state of the engine is completed ( for example, the engine speed N is a time period comparable to that required for reaching) a predetermined rotational speed N _th.

When the controller 25 detects an abnormality of the load sensor 64, the controller 25 prohibits the vibration reduction control as a process at the time of abnormality detection,
For example, a process for notifying the driver of the occurrence of an abnormality by, for example, turning on a lamp on the front of the driver's seat is executed.

Next, the operation of this embodiment will be described. That is, as a result of adjusting the resonance frequency of the fluid resonance system in the active engine mount 20 to 20 Hz, a certain amount of damping force is generated in the active engine mount 20 even when the engine shake, which is a vibration of 5 to 15 Hz, occurs. For,
The engine shake generated on the engine 17 side is attenuated to some extent by the active engine mount 20 and the engine shake is also attenuated by another fluid-filled engine mount or the like (not shown), so that the vibration level on the vehicle body 18 side is reduced. You. It is not necessary to positively displace the magnetic path forming member 78B for the engine shake.

On the other hand, when a vibration having a frequency equal to or higher than the idle vibration frequency is input, the controller 25 executes a predetermined calculation process, outputs a drive signal y to the electromagnetic actuator 52, and outputs the drive signal y to the active engine mount 20. Generate an active support force that can reduce vibration.

This will be described in detail with reference to FIG. 4 which is a flowchart showing the outline of the processing executed in the controller 25 when idle vibration and muffled sound vibration are input.
First, after a predetermined initial setting is performed in step 101, the process proceeds to step 102, where the updating reference signal ^RT is calculated based on the transfer function filter C #.
In step 102, the update reference signal ^RT for one cycle is calculated collectively.

Next, the routine proceeds to step 103, where after the counter i is cleared to zero, the routine proceeds to step 104, where the i-th filter coefficient W _{i of} the adaptive digital filter W is output as the drive signal y.

After outputting the drive signal y in step 104, the process proceeds to step 105, where the residual vibration signal e is read. Then, the process proceeds to step 106, counter j is zero cleared, then the process proceeds to step 107, j-th filter coefficient W _j of the adaptive digital filter W is updated according to equation (3) above.

When the updating process in step 107 is completed, the process proceeds to step 108, where it is determined whether or not the next reference signal x has been input. If it is determined that the reference signal x has not been input, Moves to step 109 in order to update the next filter coefficient of the adaptive digital filter W or output the drive signal y.

In step 109, it is determined whether or not the counter j has reached the number of outputs T _y (more precisely, since the counter j starts from 0, the value obtained by subtracting 1 from the number of outputs T _y ). This determination, the filter coefficient W _i of the adaptive digital filter W in step 104, after outputting the drive signal y, the filter coefficient W _i of the adaptive digital filter W, whether to update the necessary number as the drive signal y Is to judge. Therefore, if the determination in step 109 is “NO”, step 11
After incrementing the counter j by 0, step 1
Returning to step 07, the above processing is repeatedly executed.

However, the determination in step 109 is "YE
In the case of "S", it can be determined that the update processing of the necessary number of filter coefficients as the drive signal y among the filter coefficients of the adaptive digital filter W has been completed.
After shifting to 1 and incrementing the counter i, it waits for a predetermined time. This predetermined time is determined in step 104 above.
Is performed until the time corresponding to the predetermined sampling clock interval elapses from the execution of the processing of FIG. Then, when the time corresponding to the sampling clock has elapsed, the process returns to step 104 to repeatedly execute the above-described processing.

On the other hand, if it is determined in step 108 that the reference signal x has been input, the process proceeds to step 112, where the counter i (exactly, since the counter i starts from 0, 1 is added to the counter i). _Is stored as the latest output count Ty, and the process returns to step 102 to repeatedly execute the above-described processing.

As a result of repeatedly executing the processing of FIG. 4, the active engine mount 2
The filter coefficient W _i of the adaptive digital filter W is sequentially supplied as a drive signal y to the electromagnetic actuator 52 of 0 at the sampling clock interval from the time when the reference signal x is input.

As a result, the drive signal y is supplied to the exciting coil 52b.
Is generated, but the magnetic path forming member 78B includes:
Since a constant magnetic force has already been applied by the permanent magnet 52c, the magnetic force of the exciting coil 52b is
It can be considered that this acts to increase or decrease the magnetic force of 2c. As described above, when the magnetic force of the permanent magnet 52c is increased or decreased, the movable member 78 is displaced in both the forward and reverse directions. When the movable member 78 is displaced, the volume of the main fluid chamber 84 is changed, and the volume of the main fluid chamber 84 is changed. Since the expansion spring of the elastic body 32 is deformed, active support forces in both forward and reverse directions are generated in the active engine mount 20.

Then, each filter coefficient W _i of the adaptive digital filter W serving as the drive signal y is determined by a synchronous filter
Since the sequentially updated by the above equation (3) in accordance with the red-X LMS algorithm, after converged to optimum values each filter coefficient W _i of the adaptive digital filter W has passed a certain time, the drive signal y is By being supplied to the active engine mount 20, idle vibration and muffled sound vibration transmitted from the engine 17 to the vehicle body 18 via the active engine mount 20 are reduced.

The above is the operation of the vibration reduction processing executed when the vehicle is running. On the other hand, immediately after the power is supplied to the controller 25, the processing of FIG. 5 is executed in parallel with the processing of FIG. 4. First, in step 201, the engine speed detection signal N is read. The engine speed N calculated based on the calculated engine speed N is stored. Then, the process proceeds to step 202, the engine speed N and a predetermined rotational speed N _th are compared, in the case of N ≧ N _th, the step 20
The third and subsequent processes are not executed, and the abnormality detection process of this time is ended.

On the other hand, the determination in step 202 is “N
In the case of "O", the routine proceeds to step 203, where the residual vibration signal e is read. Then, the process proceeds to step 204, where it is determined whether or not the above-described predetermined time has elapsed since the start of the abnormality detection process. If not, the process returns to step 203 to read the residual vibration signal e. Step 2
When the determination at step 04 is “YES”, the process proceeds to step 205. At the time when the process proceeds to step 205, a large number of residual vibration signals e read one after another in step 203 are stored. In step 205, the maximum amplitude of the residual vibration signal e is obtained from the stored residual vibration signal e. A
Search for _max . The maximum amplitude A _max is obtained by dividing the difference between the maximum value and the minimum value of the residual vibration signal e stored in step 203 by １ ／.
Is required.

Then, the routine proceeds to step 206, where the maximum amplitude A _max is compared with the threshold value e _th, and if A _max ≧ e _th , it is determined that the load sensor 64 is normal and the current abnormality is detected. The detection processing ends.

However, the determination in step 206 is "NO".
In the case of, it is determined that an abnormality has occurred in the load sensor 64, and the process proceeds to step 207 to execute the above-described processing at the time of detecting an abnormality, and the subsequent processing of FIG. 4 is prohibited.

Here, the timing at which the abnormality detection processing shown in FIG. 5 is executed is immediately after the power is turned on to the controller 25 by turning on the ignition and immediately after the controller 25 is reset by the momentary voltage drop of the power supply. You could think so.

In the former case, the stopped engine 17
However, since the engine shifts to the idling state via the cranking state, the vibration generated by the engine 17 has a relatively large amplitude. Further, since it is intended to gradually filter coefficient W _i of the adaptive digital filter W is gradually updated toward the optimum value from the time power is applied to the controller 25, when in a cranking state, the engine vibration most reduced It reaches the load sensor 64 without being performed.

For this reason, as shown in FIG. 6A, at time t ₁ when the ignition is turned on, the vibration at substantially the same level as the vibration generated in the engine 17 reaches the load sensor 64. Therefore, the level of the residual vibration signal e immediately after the time t ₁ is large, and the level of the residual vibration signal e gradually decreases as the filter coefficient W _i of the adaptive digital filter W is updated. To go.

If a disconnection abnormality or a short circuit abnormality occurs in the load sensor 64, such a residual vibration signal e is not read, and only a signal of a noise level is detected at most.

Thus, by appropriately setting the threshold value _eth , it is possible to detect whether or not the load sensor 64 is abnormal. On the other hand, in the latter case, the engine 17 is operating, and the vibration generated by the engine 17 has a relatively small amplitude at a certain number of rotations. For this reason, unlike immediately after the ignition is turned on, as shown in FIG.
There much larger engine vibrations to the load sensor 64 is also at time t ₂ which is reset is not input. And
Since the time t ₂ the filter coefficient W _i again adaptive digital filter W immediately after is updated, the residual vibration signal e becomes smaller again.

However, in such a case, step 202
Is determined to be "YES", the processing after step 203 is executed, and it is prevented that the load sensor 64 is erroneously determined to be abnormal.

As described above, in the present embodiment, an abnormality occurs in the load sensor 64 based on both the residual vibration signal e immediately after the power is supplied to the controller 25 and the engine speed N. Since it is determined whether or not the abnormality is present, the possibility of erroneously determining the abnormality can be reduced.

Further, since the engine speed sensor 28 is provided in a normal vehicle, it is not necessary to provide a new sensor for executing the above-described abnormality detection processing, which is advantageous in cost.

Here, in the present embodiment, the engine 17
Corresponds to the vibration source, the load sensor 64 corresponds to the residual vibration detecting means, the controller 25 corresponds to the control means, the engine speed sensor 28 corresponds to the engine speed detecting means, and the processing in FIG. In response to the processing, the pulse signal generator 19 corresponds to the reference signal generating means, and in the processing of FIG. 4, the processing of outputting the filter coefficient W _i as the drive signal y in step 104 in synchronization with a predetermined sampling clock. Step 1 of FIG. 4 corresponds to the drive signal generation means.
Step 07 corresponds to the filter coefficient updating means.

FIG. 7 is a view showing a second embodiment of the present invention, and is a flow chart showing an outline of the abnormality detection processing similar to FIG. 5 in the first embodiment. Since the overall configuration and the content of the vibration reduction processing are the same as those in the first embodiment, their illustration and description are omitted, and the same processing as in FIG. Duplicate descriptions are also omitted.

That is, when the abnormality detection processing of the present embodiment is executed, at step 201, the engine speed detection signal N
Is read, the routine proceeds to step 301, where the threshold value e _th is set based on the engine speed N, and then the processing of step 203 and thereafter is executed.

That is, in the present embodiment, step 20
6, the threshold value e _th used for the determination of the controller 2
5 is set based on the engine speed N immediately after the power is turned on. And step 30
At 1, the larger threshold value _eth is set when the engine speed N is low, and the smaller threshold value _eth is set when the engine speed N is high. However, the relationship between the threshold value _eth and the engine speed N is determined by conducting experiments as appropriate for each vehicle type.

For this reason, as shown in FIGS. 6A and 6B, the threshold value e _th is set according to the vibration level of the engine 17 which should have occurred immediately after the power supply to the controller 25 is turned on. Since it is set, the possibility of erroneously determining the abnormality of the load sensor 64 can be reduced.

According to the present embodiment, the load sensor 6 can be operated even when the engine speed N is high, that is, when the controller 25 is reset due to an instantaneous voltage drop of the power supply.
4 can be determined, so that a more accurate abnormality detection process can be performed.

Here, in the present embodiment, step 20
The processing of steps 3 to 206 constitutes the judgment means, and the processing of step 301 constitutes the threshold setting means. In each of the above embodiments, the engine speed N is determined based on the output of the engine speed sensor 28. However, the present invention is not limited to this. For example, the reference signal x
May be determined on the basis of the input interval.

In each of the above embodiments, the residual vibration is detected by the load sensor 64 built in the active engine mount 20. However, the present invention is not limited to this. May be provided with an acceleration sensor for detecting floor vibration, and the output signal of the acceleration sensor may be used as the residual vibration signal e.

In each of the above embodiments, the synchronous filter is used as an algorithm for generating the drive signal y.
Although the dX LMS algorithm is applied, the applicable algorithm is not limited to this, and may be, for example, an ordinary Filtered-X LMS algorithm.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a vehicle, showing a first embodiment.

FIG. 2 is a plan view showing an example of an active engine mount.

FIG. 3 is a cross-sectional view taken along line AA and BB in FIG. 2;

FIG. 4 is a flowchart illustrating an outline of a vibration reduction process.

FIG. 5 is a flowchart illustrating an outline of an abnormality detection process according to the first embodiment.

FIG. 6 is a waveform diagram illustrating a state of generation of a residual vibration signal e.

FIG. 7 is a flowchart illustrating an outline of an abnormality detection process according to the second embodiment.

[Explanation of symbols]

17 Engine (vibration source) 18 Body 19 Pulse signal generator (reference signal generation means) 20 Active engine mount (control vibration source) 25 Controller (control means) 28 Engine speed sensor (engine speed detection means) 52 Electromagnetic actuator 64 Load sensor (residual vibration detection means)

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G05D 19/02 F16F 13/00 630C (72) Inventor Shigeki Sato 2 Takaracho, Kanagawa-ku, Yokohama-shi, Kanagawa Nissan Motor In-house F term (reference) 3D035 CA35 CA37 3J047 AA03 AB04 CA04 CB04 FA02 3J048 AB09 AB11 AB13 AB15 AD01 BA09 BE04 CB01 CB13 CB22 DA02 EA01 5H004 GA28 GA40 GB12 HA12 HB08 HB11 KA32 KC54 MA08 MA11

Claims (6)

[Claims] An active engine mount interposed between an engine and a vehicle body and capable of generating control vibration that interferes with vibration generated by the engine, and residual vibration for detecting vibration after the interference and outputting the detected vibration as a residual vibration signal. An active vibration control device for a vehicle, comprising: a detection unit; and a control unit configured to drive and control the active engine mount so as to reduce the vibration of the vehicle body based on the residual vibration signal. Engine speed detecting means for
Abnormality detection means for detecting an abnormality of the residual vibration detection means based on the residual vibration signal and the engine speed immediately after power is turned on to the control means. Vibration control device. 2. The control means includes: a reference signal generating means for detecting a state of occurrence of the vibration and outputting as a reference signal; an adaptive digital filter having a variable filter coefficient; and an adaptive digital filter based on the residual vibration signal and the reference signal. Filter coefficient updating means for updating a filter coefficient of the adaptive digital filter according to an algorithm; and drive signal generating means for generating and outputting a drive signal for driving the active engine mount based on the reference signal and the adaptive digital filter. The active vibration control device for a vehicle according to claim 1, further comprising: 3. The abnormality detection means according to claim 1, wherein said engine speed is less than a predetermined speed, and said residual vibration signal has a predetermined threshold value immediately after power-on of said control means. 3. The active vibration control device for a vehicle according to claim 1, wherein it is determined that an abnormality has occurred in the residual vibration detecting means when the value is less than the above. 4. The engine according to claim 3, wherein the predetermined rotational speed is a rotational speed at which the engine can be determined to be in a cranking state.
The active vibration control device for a vehicle as described in the above. 5. An abnormality detecting means for detecting an abnormality in said residual vibration detecting means when the magnitude of said residual vibration signal immediately after power-on to said control means is smaller than a predetermined threshold value. 3. The active vibration control device for a vehicle according to claim 1, further comprising: a determination unit configured to determine that there is a vehicle; and a threshold setting unit configured to set the threshold based on the engine speed. 6. The active vibration control device for a vehicle according to claim 5, wherein said threshold value setting means sets said threshold value smaller when said engine speed is high than when said engine speed is low. .