JP3124382B2 - Vehicle vibration reduction device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration reducing device for a vehicle, and more particularly to a device for separately providing an actuator for vibrating a vehicle body .
From its body vibration of the vehicle body to vibrate at the same amplitude in phase opposition, the car
The present invention relates to an improvement of a body vibration reducing device.

[0002]

2. Description of the Related Art Conventionally, as a vehicle vibration reducing device of this type, for example, as disclosed in Japanese Patent Application Laid-Open No. 1-501344, there is provided a vibrator attached to a vehicle body to vibrate the vehicle body. setting controls the vibrator to impart vibrations of opposite phase to the vehicle body, when the amplitude of the vibration of the vehicle body is large, the gain of the excitation signal output to vibrator in large relative vibration of the phase And the amplitude of the vibration added by the shaker
It is known that the amplitude of the vehicle body vibration is substantially the same as that of the vehicle body vibration, thereby effectively reducing the vehicle body vibration.

[0003]

In recent years, active suspensions and suspension devices having variable damping characteristics such that the damping force can be switched stepwise have been developed, and vehicles having such suspension devices have been developed. In the above, the vibration state of the vehicle body described above changes with a change in the cushioning characteristic of the suspension device. In other words, the vibration transmission characteristics of the vehicle body change due to the cushioning characteristics of the suspension device, and the vibration generation state changes accordingly.

However, in the conventional vibration reducing device, when the vibration generation state of the vehicle body changes as described above, the vibration is detected by a vibration sensor, and feedback control is performed to reduce the vibration. The vibration is reduced by performing the above. For this reason, there is a problem that the convergence of the vibration reduction operation is poor, and the vibration cannot be rapidly reduced. Therefore, the inventors of the present invention paid attention to the correlation between the change in vibration of the vehicle body and the shock absorbing characteristics of the suspension device, and considered recognizing the vibration state of the vehicle body by detecting the suspension characteristics.

[0005] The present invention has been made in view of the above, and an object of the present invention is to provide a structure capable of performing a vibration reduction operation capable of rapidly reducing the vibration of a vehicle body.

[0006]

In order to achieve the above object, the present invention changes a transfer function of a digital filter for generating a drive signal for driving and controlling an actuator according to a buffering characteristic of a suspension device. I did it. Specifically, an invention according to claim 1, wherein, as shown in FIG. 1, is disposed between the vehicle body and the engine 2 of a vehicle provided with a suspension system damping characteristics is variable, the vehicle body <br / > an actuator 3 to vibrate and the vibration sensor 7 for detecting vibration of the vehicle body, receives a reference signal based on the vibration emanating from the engine 2, reverse phase and the vibration of the vehicle body based on the reference signal Control means 24 for generating a drive signal for exciting the vehicle body with the same amplitude. The control means 24 includes a digital filter 20 having a transfer function corresponding to the vibration transfer characteristic of the vehicle body. When a drive signal feedback-corrected based on the transfer function of the digital filter 20 and the vibration signal of the vibration sensor 7 is transmitted to the actuator 3, Chueta 3 is assumed vibration damping system for a vehicle that is configured to reduce vibration of the vehicle body to vibrate the body. Then, the transfer function of the digital filter 20 has a configuration such as providing a transfer function changing means 30 for changing, based on the damping characteristics of the suspension device.

According to a second aspect of the present invention, in the vehicle vibration reducing device according to the first aspect, the transfer function changing means includes:
The transfer function of the digital filter is changed according to the change in the damping force of the suspension device.

According to a third aspect of the present invention, in the vehicle vibration reducing device according to the first or second aspect, the transfer function changing means changes the transfer function of the digital filter according to a change in the spring force of the suspension device. It has such a configuration.

[0009]

According to the present invention, the following effects can be obtained. According to the first aspect of the present invention, a control signal based on a reference signal based on vibration generated from the engine 2 and a vibration signal of a vibration sensor 7 for detecting vibration of a vehicle body are provided.
4 receives, the control means 24, said the vibration of the vehicle body based on the reference signal to create a drive signal to vibrate the said body in opposite phases and the same amplitude. In addition, a drive signal feedback-corrected based on the transfer function of the digital filter 20 and the vibration signal of the vibration sensor 7 is transmitted to the actuator 3 so that the actuator 3
There reduce vibration of the vehicle body to vibrate the body. Then, at this time, the transfer function of the digital filter 20 is changed by the transfer function changing means 30 based on the buffer characteristics of the suspension device. Therefore, the actuator 3
Performs the optimal vibration reduction operation according to the control state of the suspension device, and the vibration of the vehicle body can be reduced efficiently.

According to the second and third aspects of the present invention, the transfer function of the digital filter is changed in accordance with the change in the damping force or the spring force of the suspension device, so that the actuator is optimized for the control state of the suspension device. The vibration reduction operation is performed. That is, the optimum transfer function is set by recognizing the transmission characteristics of the vibration of the vehicle body based on the damping force and the spring force.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

In FIG. 2, reference numeral 1 denotes a vehicle body, and 2 denotes an engine disposed in an engine room 1b below a hood 1a of the vehicle body 1. The engine 2 has a mount 3 and a support bracket 4 for elastically supporting a lower portion thereof. Body 1 through
The engine 2 and the vehicle body 1 constitute an entire vehicle. Further, the vehicle has an active suspension as a suspension device, and its cushioning characteristics are changed according to road surface conditions and the like.

As shown in FIG. 3, the mount 3 has a function as an actuator for exciting the engine 2 as a vibration source. That is, the mount 3 shown in the figure is composed of a casing 3b in which an insertion rod 3a to which the lower end of the engine 2 is fixed is disposed at the upper end, and a hollow cone-shaped support rubber having an outer peripheral end fixed to the lower end of the casing 3b. 3c and a support portion 3d having an inner peripheral end of the support rubber 3c fixed thereto, and an insertion rod 3e provided at a lower end of the support portion 3d is fixed to the vehicle body 1.

A main liquid chamber 3f is formed in the casing 3b, and a sub liquid chamber 3h partitioned by a diaphragm 3g is formed below the support rubber 3c. A small-diameter orifice 3i formed on the side of the support rubber 3c is formed between the main liquid chamber 3f and the sub liquid chamber 3h, and the fluid between the main liquid chamber 3f and the sub liquid chamber 3h is supplied to the orifice 3i. It is a configuration in which they are mutually circulated through the Internet. Further, the casing 3b
Inside, a vibration plate 3j forming the upper surface of the main liquid chamber 3f is disposed via a rubber 3k so as to be slidable up and down on the inner peripheral surface of the casing 3b, and above the vibration plate 3j, A permanent magnet 3m and an electromagnetic coil 3n that slide the vibration plate 3j up and down are arranged, and the vibration plate 3j is vertically vibrated by the permanent magnet 3m and the electromagnetic coil 3n to reduce the volume of the main liquid chamber 3f. By making them variable, the main liquid chamber 3f and the sub liquid chamber 3h
By repeating the flow of the fluid through the orifice 3i, the support rubber 3c is vibrated up and down, and as a result, an exciting force is generated.

Further, in FIG. 2, 7 vehicle body by the vertical acceleration of the vehicle body 1 is disposed at the position of the left front wheel near the vehicles 1
A detection signal of the acceleration sensor 7 is input to a controller 8, and the controller 8 detects the vibration of the engine based on a vertical acceleration signal detected by the acceleration sensor 7. By controlling the vibration of the mount 3 and causing the engine 2 to vibrate up and down,
This is a configuration for reducing vibration of the vehicle body 1 as a vibration element according to the present invention.

Next, FIG. 4 shows a block configuration of the vehicle body vibration reduction control by the controller 8. In the figure, reference numeral 10 denotes an engine rotation period measuring circuit for measuring an engine rotation period based on an ignition signal of an air-fuel mixture in the engine 2, and 11 denotes an engine rotation period measured by the period measuring circuit 10. The reference signal generator generates a reference signal R related to the vibration of the engine 2. An amplifier 12 amplifies an acceleration signal as a vibration signal from the acceleration sensor 7 with a set gain G2.
Reference numeral 13 denotes a low-pass filter that filters low-frequency components of the acceleration signal amplified by the amplifier 12, reference numeral 14 denotes an A / D converter that converts the acceleration signal filtered by the low-pass filter 13 from an analog value to a digital value, and 15 denotes a digital signal. An excitation signal generator that receives an acceleration signal S from the A / D converter 14 and generates an excitation signal A as a drive signal for controlling the excitation of the engine mount 3 based on the acceleration signal S. . Further, 17 is a D / A converter for converting the excitation signal A generated by the excitation signal generator 15 from a digital value to an analog value, and 18 is the D / A converter of the excitation signal from the D / A converter 17. A low-pass filter for filtering low-frequency components, and 19 is an amplifier for amplifying the excitation signal filtered by the low-pass filter 18 with a set gain G1, and the excitation signal amplified by the amplifier 19 is supplied to the engine mount 3. Is output.

The excitation signal generator 15 uses a least-squares method (Least square method) as an algorithm for generating the excitation signal.
Mean Square Method (= LM
The adaptive algorithm of S)) is used. FIG. 5 shows the internal configuration of the excitation signal generator 15 using the least squares adaptive algorithm. In the figure, reference numeral 20 denotes an excitation signal A output from the excitation signal generator 15, and the mount 3 is controlled to be excited by the excitation signal A. As a result, a change in the vehicle body vibration occurs. The change in vehicle body vibration is detected by the acceleration sensor 7.
Is a digital filter which models a transfer function H from the time when the acceleration signal S is detected to the time when the acceleration signal S is input to the excitation signal generator 15. The digital filter 21 rewrites the filter coefficient according to the acceleration signal S from the acceleration sensor 7 A convergence coefficient calculating circuit for calculating the convergence coefficient α of the reference signal R
Is multiplied by a transfer function H and a convergence coefficient α. The filter 23 sequentially updates the filter coefficient based on the output value of each output of the multiplier 22, and determines the reference signal based on the updated filter coefficient. This is an adaptive filter that outputs the excitation signal A having the same amplitude in the opposite phase. Therefore, the excitation signal generator 1
5 receives the acceleration signal S from the acceleration sensor 7,
Based on the acceleration signal S and the convergence coefficient, the adaptive filter 23
The excitation coefficient A is appropriately adjusted by updating the filter coefficient of the above, and the drive of the engine mount 3 is controlled by the excitation signal A,
The control means 24 is configured to reduce the vibration of the vehicle body 1 by setting the phase and the amplitude of the vibration applied to the vehicle body 1 to the same amplitude as the opposite phase to the vibration of the engine 2.

As a characteristic feature of this embodiment, the excitation signal generator 15 includes the digital filter 20.
Is provided with a transfer characteristic adjusting mechanism 26 for changing the transfer function. The transfer characteristic adjusting mechanism 26 includes:
A spring constant signal and a damping force signal from the suspension characteristic changing means 27 for controlling the above-described active suspension device are input, and the transfer characteristic adjusting mechanism 26 transmits the digital filter 20 based on these signals. To change the transfer function. As a result, the transfer function adjusting means 26 and the suspension characteristic changing means 27 allow the transfer function changing means 30 according to the present invention.
Is configured.

Therefore, the digital filter 2 in the present embodiment
In the transfer function changing operation of 0, the cushioning characteristic of the suspension device is detected based on the spring constant signal and the damping force signal output from the suspension characteristic changing means 27. Based on this, the transfer function is determined by the memory map shown in FIG. Calculate the coefficient vector for setting. Explaining this memory map, a coefficient vector is set according to the spring constant and the damping force of the suspension device. For example, when the spring constant is large and the damping force is large, the coefficient vector is set to hHH and the spring constant is set. Is small and the damping force is small, the coefficient vector is set to hSS, and the transfer function of the digital filter 20 is calculated based on the set coefficient vector.
In other words, a transfer function is set according to the transfer characteristics of the vehicle body 1 that change due to changes in the spring constant and the damping force that accompany changes in the cushioning characteristics of the suspension device.

As described above, according to the configuration of the present embodiment, the vehicle body 1 that changes due to the change in the shock absorbing characteristics of the suspension device
The excitation signal is corrected by changing the transfer function of the digital filter 20 in accordance with the transfer characteristic of the engine mount 3 so that the engine mount 3 can be adjusted in accordance with the state of the suspension device.
, The vibration of the vehicle body 1 can be reduced efficiently, and as a result, the quietness of the vehicle is improved.

The position of the acceleration sensor 7 is as follows.
It is desirable to dispose it on various vibration generating parts such as a floor panel, a door inner panel, a steering wheel, a shift knob and the like.
Further, the present invention can be applied not only to a vehicle equipped with an active suspension device, but also to a vehicle equipped with a suspension device configured so that damping force can be switched stepwise.

[0022]

As described above, according to the present invention, the following effects can be obtained. According to the first aspect of the present invention, since the transfer function changing means for changing the transfer function of the digital filter based on the buffer characteristic of the suspension device is provided, the actuator is adapted to the control state of the suspension device. Optimal vibration reduction operation can be performed, and vibration of the vehicle body can be reduced efficiently.

According to the second and third aspects of the present invention, the transfer function changing means is configured to change the transfer function of the digital filter according to a change in the damping force of the suspension device or a change in the spring force. Therefore, the shock absorbing characteristics of the suspension device can be easily recognized, and the transfer characteristics of the vibration of the vehicle body accompanying the suspension characteristics can be quickly recognized, so that the optimum transfer function can be set.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of the present invention.

FIG. 2 is a diagram showing an overall schematic configuration of a vehicle.

FIG. 3 is a diagram showing a specific configuration of an engine mount that also serves as a vibration control actuator.

FIG. 4 is a diagram showing a block configuration of vibration control.

FIG. 5 is a diagram showing a configuration of an excitation signal generator using an adaptive algorithm of LMS.

FIG. 6 is a diagram showing a memory map for setting a coefficient vector according to a buffer characteristic of a suspension device.

[Explanation of symbols]

1 car body 2 Engine 3 engine mount (actuator) 7 acceleration sensor (vibration sensor) 20 digital filter 24 controller 30 transfer function changing means R reference signal S acceleration signal (vibration signal) A vibration signal (drive signal) H transfer function

──────────────────────────────────────────────────続 き Continued on the front page (72) Norihiko Nakao, Inventor No. 3-1 Shinchi, Fuchu-cho, Aki-gun, Hiroshima Mazda Co., Ltd. (72) Inventor Chiaki Mitsui No. 3-1 Shinchi, Fuchu-cho, Aki-gun, Hiroshima Pref. Inside (72) Inventor Hiroshi Tsukahara 3-1 Shinchi, Fuchu-cho, Aki-gun, Hiroshima Prefecture Inside Mazda Corporation (72) Insider Shingo Harada 3-1 Shinchi, Fuchu-cho, Aki-gun, Hiroshima Prefecture Inside Mazda Corporation (56) References JP-A-3-284406 (JP, A) JP-A-65-155211 (JP, U) JP-A-60-88137 (JP, U) (58) Fields investigated (Int. Cl. ⁷⁾ , DB name) B60G 17/015 B60G 17/08 F16F 15/02 G05D 19/02

Claims (3)

(57) [Claims] 1. A vehicle equipped with a suspension device having a variable cushioning characteristic, disposed between a vehicle body and an engine ,
An actuator for vibrating the vehicle body, a vibration sensor for detecting vibration of the vehicle body, receives a reference signal based on the vibration emanating from the engine, the vibration of the vehicle body on the basis of the reference signal in opposite phase and the same amplitude and a control means for generating a drive signal which vibration the vehicle body, the control means is provided with a digital filter having a transfer function in accordance with the vibration transmission characteristics of the vehicle body,
The actuator by the feedback corrected drive signal based on the transfer function and the vibration signal of the vibration sensor of the digital filter is sent to the actuator to vibrate the vehicle body so as to reduce the vibration of the vehicle body in the vibration reduction apparatus of a vehicle constructed, the transfer function of the digital filter, of the vehicle, characterized in that the Suspension <br/> transfer function changing means for changing, based on the damping characteristics of the emission device is provided Vibration reduction device. 2. The vehicle vibration reduction device according to claim 1, wherein the transfer function changing means is configured to change a transfer function of the digital filter according to a change in damping force of the suspension device. . 3. The vibration of a vehicle according to claim 1, wherein the transfer function changing means is configured to change a transfer function of the digital filter in accordance with a change in a spring force of the suspension device. Reduction device.