JP2012082866A - Vibration reducing system of vehicle and vibration reducing method of vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vibration reducing system of a vehicle capable of reducing the transmission of excessive vibration such as cranking vibration upon an idling stop.SOLUTION: A control device 11 generates a reference signal whose signal frequency is a real number multiple of a resonance frequency of an engine and generates vibration adding forces in ACMs 3a and 3b on the basis of a signal obtained from a sensor 9 and the reference signal to perform control so that vibration caused in a prescribed position in a vehicle 10 is reduced. The control device 11 monitors the signal from the sensor 9 and when the deviation of the resonance frequency is detected, corrects the resonance frequency by frequency analysis.

Description

  The present invention relates to a vibration reduction system and a vehicle vibration reduction method for reducing vibration at a predetermined position in a vehicle.

In recent years, an increasing number of vehicles are equipped with an idling stop mechanism that stops the engine when it is red and restarts the engine when starting off due to consideration of the global environment due to exhaust gas from the engine. As a result, the engine vibration force is also increasing. Therefore, it is required to reduce transient vibration such as engine vibration (cranking vibration) at idling stop.
As a countermeasure, conventionally, the design parameters of the engine mount are mainly adjusted with respect to the cranking vibration in the frequency domain, thereby reducing the target cranking vibration. In addition, an engine mount having a mechanism for switching engine mount characteristics with respect to various vibrations such as cranking vibration and idling vibration has been designed to reduce the target vibration (Patent Document). 1).
However, since engine mounts are required to reduce a wide range of vibrations such as cranking vibration, idling vibration, shake vibration, and vehicle acceleration vibration, all vibrations can be completely reduced by adjusting various engine mount design parameters. It is difficult to reduce.

In addition, in order to reduce the transmission of vibration in a predetermined direction of the engine mounted on the vehicle to various parts of the vehicle, an active vibration isolator (active control mount) that fixes the sensor for detecting vibration to the engine and controls the engine (Hereinafter referred to as "ACM"), and the engine damping system controls the damping force of the ACM based on the reference signal obtained from the crank rotation pulse signal and the ignition ignition pulse signal and the signal from the sensor. The system is known.
When trying to reduce cranking vibration using this engine damping system, the engine stops when idling stops, so the crank rotation pulse signal and ignition ignition pulse signal cannot be used as control reference signals. Therefore, the resonance frequency of the engine is specified in advance, and a pulse signal of that frequency is artificially created and used as a reference signal.

JP 2001-277865 A

  However, when vibration is reduced using an engine damping system, the resonance frequency in the engine's predetermined direction (front / rear or up / down) varies slightly depending on the temperature of the engine mount and aging (for example, starting) Immediately after driving for a long time, a new car and a 100,000-kilometer vehicle), and the transmission characteristics from the ACM to the sensor differ depending on the traveling environment, and the vibration reduction effect by the ACM becomes worse. Such a problem can be dealt with by preliminarily storing information on the resonance frequency and transfer characteristics for each temperature and for each driving age, but enormous information is required.

  The present invention has been made in view of such problems, and an object of the present invention is to provide a vehicle vibration reduction system and a vehicle vibration reduction method that reduce transient vibration such as cranking vibration during idling stop. To do.

  In order to achieve the above object, the first invention provides at least one vibration generating device for generating a vibration force, a device for detecting vibration at a predetermined position in the vehicle, and a signal frequency of the resonance frequency of the power source. A vibration signal generated at a predetermined position in the vehicle is generated by generating a vibration force in the vibration generator based on the reference signal and a signal obtained from a device that generates a real number multiple reference signal and detects the vibration. A vibration reduction system for a vehicle including a control device that controls to reduce the frequency when the control device monitors a signal from a device that detects the vibration and detects a deviation of the resonance frequency. The resonance frequency is corrected by analysis.

  According to a second aspect, in the first aspect, the vibration device is provided between the suspension device and the vehicle body.

  According to a third aspect of the invention, there is provided at least one vibration generating device that generates a vibration force, a device that detects vibration at a predetermined position in the vehicle, and a reference signal whose signal frequency is a real number multiple of the resonance frequency of the power source. And controlling the vibration generating device to generate a vibration force based on a signal obtained from the vibration detecting device and the reference signal so as to reduce the vibration generated at a predetermined position in the vehicle. A vibration reduction method for a vehicle in a system including an apparatus, wherein a processing procedure of the control device monitors a signal from a device that detects the vibration, and when a deviation of the resonance frequency is detected, a frequency Correcting the resonance frequency by analysis.

  According to the first and third aspects of the present invention, the reference signal is generated from the resonance frequency signal of the engine, and the excitation device generates the excitation force based on the signal obtained from the vibration detection device and the reference signal. Therefore, control is performed to reduce the vibration generated at a predetermined position in the vehicle, and the signal is captured by a device that detects vibration, and the resonance frequency is corrected by frequency analysis. Vibration can be reduced even during transient vibration such as vibration.

  According to the second invention, the vibration of the vehicle can be reduced by providing the vibration exciting device between the suspension device and the vehicle body.

1 is a schematic diagram showing a first embodiment of a vehicle vibration reduction system according to the present invention. 1 is a block diagram showing a basic control system according to a first embodiment of a vehicle vibration reduction system. FIG. It is a flowchart explaining the Example of the processing operation which correct | amends the resonant frequency of an engine. It is a figure which shows an example of the vibration waveform at the time of idling stop. It is a flowchart explaining the other Example of the processing operation which correct | amends the resonance frequency of an engine. It is a block diagram when the control system which concerns on a 1st Example is comprised with a SAN filter. It is a flowchart explaining the Example of the processing operation which correct | amends the resonant frequency of an engine. It is a flowchart explaining the other Example of the processing operation which correct | amends the resonance frequency of an engine. It is a schematic diagram which shows the 2nd Example of the vibration reduction system of the vehicle which concerns on this invention. It is a block diagram which shows the basic control system which concerns on 2nd Example of the vibration reduction system of a vehicle.

  Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram showing a first embodiment of a vehicle vibration reduction system according to the present invention. In FIG. 1, the engine 12 is supported by an active control mount (ACM) 3 a having a built-in actuator such as a voice coil and a plurality of engine mounts 5. It has a function as a device and functions to suppress vibration at a predetermined position in the vehicle by actively applying an excitation force to the engine 12. Further, a sensor 9 for detecting vibration is attached to the floor portion of the driver's seat, and a control device 11 that controls the damping force of the ACM 3a is located at the front portion of the driver's seat (for example, in the instrument panel). Has been placed.

  The sensor 9 that detects vibration functions to detect vibration (for example, acceleration) at a predetermined position in the vehicle in real time, and is located at a place where a passenger feels or a vibration source (a vehicle body, in the vicinity of the vibration device). It is preferable to be disposed. In the first embodiment, it is disposed on the floor portion of the driver's seat, but may be disposed on the steering 4, the seat 13, the vehicle body 14, the headrest portion of the front seat, the floor portion of the rear seat, and the like. As the sensor 9, for example, an acceleration sensor, a load sensor, or the like can be used. The control device 11 may be arranged at any location in the vehicle.

  FIG. 2 is a block diagram showing a basic control system according to the first embodiment of the vehicle vibration reduction system. In the first embodiment, the control device 11 reduces vibration with a sensor that detects one ACM and one vibration.

  In this embodiment, as shown in FIG. 2, the control device 11 generates a reference signal (basic frequency signal and its harmonic signal), and a reference signal x (t) output from the synthesizer 16. The adaptive filter 17 that outputs the control signal y (t) of the ACM 3a by adjusting the phase and gain, the reference signal from the synthesizer 16, and the acceleration signal (error signal) e (t) detected by the sensor 9 are read. And an LMS calculation unit 18 that performs a process of updating the filter coefficient of the adaptive filter 17.

  In FIG. 2, C indicates the actual transfer characteristic from the ACM 3a to the sensor 9, and C 'indicates the estimated transfer characteristic (measured impulse response).

  The control device 11 generates a pulse signal of the engine resonance frequency based on the information of the engine resonance frequency set at the time of the previous engine start or stop, and the signal frequency is generated by the synthesizer 16 based on the generated pulse signal. Generates a reference signal that is a real number multiple of the resonance frequency (fundamental frequency) of the engine. The LMS calculation unit 18 reads the reference signal, further reads the error signal e (t) from the sensor 9, and updates the filter coefficient of the adaptive filter 17 using a LMS (Least Mean Square) algorithm. The adaptive filter 17 outputs the control signal y (t) to the ACM 3a based on the updated filter coefficient.

  In addition, since the vibration generated in the vehicle is synthesized with various phases and the vibration with a frequency of 0.5 times or 1.5 times may increase, in the present invention, the fundamental frequency of the pulse signal is increased by the synthesizer. A reference signal that is a real number multiple is generated and combined.

  FIG. 3 is a flowchart for explaining an embodiment of the processing operation for correcting the resonance frequency of the engine. The resonant frequency of the engine changes with temperature and aging. If the resonance frequency is changed, the effect of suppressing vibration is reduced. Therefore, when it is determined that the vibration reduction amount has decreased (when the vibration reduction amount is equal to or less than a predetermined threshold value), the control device 11 performs a process of correcting the resonance frequency.

  When the engine is stopped (idling stop) (S101), the control device 11 takes in a signal from the sensor 9 for a certain time (S102), performs frequency analysis or extraction in the time domain, and calculates a resonance frequency (S103). ). Next, it is determined whether or not the resonance frequency has changed from the previously set resonance frequency (S104). If the resonance frequency has changed from the set resonance frequency (Yes), the resonance frequency is corrected (S105). Then, a pulse signal having a newly set resonance frequency (the number of pulses is arbitrary) is created (S106).

  FIG. 4 shows an example of a vibration waveform at the time of idling stop taken from a sensor installed on the floor, FIG. 4 (a) shows a vibration waveform at a certain time (previous time), and FIG. The vibration waveform at a certain time (this time) is shown. The horizontal axis indicates time (seconds), and the vertical axis indicates acceleration (m / s2). The control device 11 performs extraction in a region of a fixed time after idling stop surrounded by a solid line, calculates the resonance frequency, and corrects the resonance frequency if there is a change.

  FIG. 5 is a flowchart for explaining another embodiment of the processing operation for correcting the resonance frequency of the engine.

  The control device 11 vibrates the vibration device (S201), takes in a signal from the sensor 9 for a certain time (S202), and extracts a specific frequency in the frequency domain or the time domain (S203). Next, it is determined whether or not the resonance frequency has changed from the previously set resonance frequency (S204). If the resonance frequency has changed from the set resonance frequency (Yes), the resonance frequency is corrected (S205). Then, a pulse signal having a set resonance frequency (the number of pulses is arbitrary) is created (S206).

  In the embodiment shown in FIG. 5, the resonance frequency of the engine can be corrected by exciting the vibration device at an arbitrary time, not only when the engine is started or stopped. Therefore, the control device 11 may constantly monitor the signal from the sensor 9 and correct the resonance frequency by frequency analysis when a deviation of the resonance frequency is detected.

  In S202, when the signal from the sensor is captured, the transfer characteristic may be calculated. If the transfer characteristic is changed from the previously set transfer characteristic, the transfer characteristic may be corrected. The effect of suppressing vibration is not limited to the case where the resonance frequency changes due to temperature and aging deterioration, but also decreases when the transfer characteristic changes due to temperature and aging deterioration, so that the control device 11 reduces the amount of vibration reduction. When it is determined that the vibration has been reduced (when the vibration reduction amount is equal to or less than a predetermined threshold), the resonance frequency may be corrected and the transfer characteristic may be corrected.

  Further, the control system according to the first embodiment may be configured by a SAN filter (Single frequency Adaptive Notch filter). The configuration with the SAN filter is more advantageous in terms of calculation amount. FIG. 6 is a block diagram when the control system according to the first embodiment is configured by a SAN filter.

  As shown in FIG. 6, the control device 11 includes a cosine wave generator 31 that generates a cosine wave having a set frequency (resonance frequency) and a frequency that is a real number thereof, and a set frequency (resonance frequency) and a real number that is a multiple of the cosine wave. A sine wave generator 32 that generates a sine wave of frequency, an adaptive filter 33 that adjusts the gain and phase of the reference signal output from the cosine wave generator 31, and the gain of the reference signal output from the sine wave generator 32 And an adaptive filter 34 that adjusts the phase, and an adder 35 that adds the control signal from the adaptive filter 33 and the control signal from the adaptive filter 34 and outputs the control signal y (t) to the ACM (actuator) 3a; , An adder 36 for adding the reference signal from the cosine wave generator 31 and the reference signal from the sine wave generator 32, the reference signal from the adder 36 and the acceleration signal (error signal) detected by the sensor 9. ) LMS calculation unit 37 that reads e (t) and updates the filter coefficient of the adaptive filter 33, and an addition that adds the reference signal from the cosine wave generator 31 and the reference signal from the sine wave generator 32 And an LMS calculation unit 39 that reads the reference signal from the adder 38 and the acceleration signal (error signal) e (t) detected by the sensor 9 and updates the filter coefficient of the adaptive filter 34. Yes.

  In FIG. 6, C indicates the actual transfer characteristics from the ACM 3a to the sensor 9, and Cr (f) and Ci (f) indicate the estimated transfer characteristics at each frequency. Cr (f) and Ci (f) are obtained in advance at each frequency.

  The control device 11 generates a sine wave / cosine wave having a fundamental frequency and a harmonic multiple of the fundamental frequency based on information on the resonance frequency of the engine set at the time of the previous engine start or stop. The LMS calculation units 37 and 39 read the reference signal, further read the error signal e (t) from the sensor 9, and update the filter coefficients of the adaptive filters 33 and 34 using an LMS (Least Mean Square) algorithm. . The adaptive filters 33 and 34 output the control signal y (t) to the ACM 3a based on the updated filter coefficient.

  In addition, since the vibration generated in the vehicle is synthesized with various phases and the vibration of the frequency of 0.5 times or 1.5 times may increase, in the present invention, the sine wave / cosine wave generator A sine wave and cosine wave of the set frequency and its real number are generated.

  FIG. 7 is a flowchart for explaining an embodiment of the processing operation for correcting the resonance frequency of the engine. When it is determined that the vibration reduction amount has decreased (when the vibration reduction amount is equal to or less than a predetermined threshold), the control device 11 performs a process of correcting the resonance frequency. When the engine is stopped (idling stop) (S301), the control device 11 takes in a signal from the sensor 9 for a certain time (S302), performs frequency analysis or extraction in the time domain, and calculates a resonance frequency (S303). ). Next, it is determined whether or not the resonance frequency has changed from the previously set resonance frequency (S304). If the resonance frequency has changed from the set resonance frequency (Yes), the resonance frequency is corrected (S305).

  FIG. 8 is a flowchart for explaining another embodiment of the processing operation for correcting the resonance frequency of the engine. The control device 11 vibrates the vibration device (S401), takes in a signal from the sensor 9 for a certain time (S402), and extracts a specific frequency in the frequency domain or the time domain (S403). Next, it is determined whether or not the resonance frequency has changed from the previously set resonance frequency (S404). If the resonance frequency has changed from the set resonance frequency (Yes), the resonance frequency is corrected (S405).

  In the embodiment shown in FIG. 8, the resonance frequency of the engine can be corrected by exciting the vibration device at an arbitrary time, not only when the engine is started or stopped. Therefore, the control device 11 may constantly monitor the signal from the sensor 9 and correct the resonance frequency by frequency analysis when a deviation of the resonance frequency is detected.

  In S402, when the signal from the sensor 9 is captured, the transfer characteristic may be calculated. If the transfer characteristic is changed from the previously set transfer characteristic, the transfer characteristic may be corrected. The effect of suppressing vibration is not limited to the case where the resonance frequency changes due to temperature and aging deterioration, but also decreases when the transfer characteristic changes due to temperature and aging deterioration, so that the control device 11 reduces the amount of vibration reduction. When it is determined that the vibration has been reduced (when the vibration reduction amount is equal to or less than a predetermined threshold), the resonance frequency may be corrected and the transfer characteristic may be corrected.

  FIG. 9 is a schematic diagram showing a second embodiment of the vehicle vibration reduction system according to the present invention. In FIG. 9, the engine 12 is supported by two ACMs 3 a and 3 b and a plurality of engine mounts (not shown). The ACMs 3 a and 3 b function as a vibration device as well as a function of supporting the engine 12. And functions to suppress vibration at a predetermined position in the vehicle by actively applying an excitation force to the engine 12. In addition, a sensor 9a that detects vibration is attached to the steering 4 of the vehicle 10, and a sensor 9b that detects vibration is attached to the floor of the driver's seat. In the following description, the sensors 9a and 9b are referred to as sensors 9 unless otherwise distinguished. In addition, a control device 11 that controls the damping force of the ACMs 3a and 3b is disposed at the front position of the driver's seat (for example, in the instrument panel).

  The sensor 9 that detects vibration functions to detect vibration (for example, acceleration) at a predetermined position in the vehicle in real time, and is located at a place where a passenger feels or a vibration source (a vehicle body, in the vicinity of the vibration device). It is preferable to be disposed. In the second embodiment, the vehicle is disposed on the steering 4 or on the floor of the driver's seat, but may be provided on the seat 13, the vehicle body 14, the headrest of the front seat, the floor of the rear seat, or the like. As the sensor 9, for example, an acceleration sensor, a load sensor, or the like can be used. The control device 11 may be arranged at any location in the vehicle.

  FIG. 10 is a block diagram showing a basic control system according to the second embodiment of the vehicle vibration reduction system. In the second embodiment, the control device 11 reduces vibrations with two ACMs and sensors that detect two vibrations.

  In the present embodiment, as shown in FIG. 10, the control device 11 synthesizer 21 that generates a reference signal (basic frequency signal and its harmonic signal), and a reference signal x (t) output from the synthesizer 21. The adaptive filter 22 that outputs the control signal y1 (t) of the ACM 3a by adjusting the phase, gain, etc., the reference signal from the synthesizer 21, and the acceleration signal (error signal) e1 (t) detected by the sensor 9a The LMS calculation unit 23 that reads and updates the filter coefficient of the adaptive filter 22, the reference signal from the synthesizer 21, and the acceleration signal (error signal) e2 (t) detected by the sensor 9b are read and the adaptive filter 22 An LMS operation unit 24 that performs filter coefficient update processing and an AC by adjusting the phase and gain of the reference signal x (t) output from the synthesizer 21 The adaptive filter 25 that outputs the control signal y2 (t) of 3b, the reference signal from the synthesizer 21, and the acceleration signal (error signal) e1 (t) detected by the sensor 9a are read and the filter coefficient of the adaptive filter 25 is read LMS calculation for updating the filter coefficient of the adaptive filter 25 by reading the reference signal from the LMS calculation unit 26 that performs the update process, the reference signal from the synthesizer 21, and the acceleration signal (error signal) e2 (t) detected by the sensor 9b Part 27.

  In FIG. 10, C11 is the actual transfer characteristic from the ACM 3a to the sensor 9a, C12 is the actual transfer characteristic from the ACM 3a to the sensor 9b, C21 is the actual transfer characteristic from the ACM 3b to the sensor 9a, and C22 is the sensor from the ACM 3b to the sensor 9a. Actual transfer characteristics up to 9b are shown, and C11 ′, C12 ′, C21 ′, and C22 ′ show estimated transfer characteristics.

  The control device 11 generates a pulse signal of the engine resonance frequency based on the information of the engine resonance frequency set at the time of the previous engine start or stop, and the signal frequency is generated by the synthesizer 16 based on the generated pulse signal. Generates a reference signal that is a real number multiple of the resonance frequency (fundamental frequency) of the engine. The LMS calculation unit 23 reads the reference signal, further reads the error signal e1 (t) from the sensor 9a, and performs the update process of the filter coefficient of the adaptive filter 22 using the LMS algorithm. The LMS calculation unit 24 reads the reference signal, further reads the error signal e2 (t) from the sensor 9b, and updates the filter coefficient of the adaptive filter 22 using the LMS algorithm. The adaptive filter 22 outputs a control signal y1 (t) to the ACM 3a based on the updated filter coefficient.

  Further, the LMS calculation unit 26 reads the reference signal, further reads the error signal e1 (t) from the sensor 9a, and updates the filter coefficient of the adaptive filter 25 using the LMS algorithm. The LMS calculation unit 27 reads the reference signal, further reads the error signal e2 (t) from the sensor 9b, and updates the filter coefficient of the adaptive filter 25 using the LMS algorithm. The adaptive filter 25 outputs the control signal y2 (t) to the ACM 3b based on the updated filter coefficient.

  The resonant frequency of the engine changes with temperature and aging. If the resonance frequency is changed, the effect of suppressing vibration is reduced. Therefore, when it is determined that the amount of vibration reduction has decreased (when the amount of vibration reduction is equal to or less than a predetermined threshold value), the control device 11 is shown in FIGS. 3 and 5 as in the first embodiment. As described above, the resonance frequency of the engine is corrected.

  In the second embodiment, two sensors for detecting vibration are used separately, but a single sensor for detecting vibration may be used in common. When one sensor for detecting vibration is used, the transfer characteristics C12 and C21 need not be considered.

  Also, in FIG. 6, the control system of the vehicle vibration reduction system may be configured with a SAN filter in the second embodiment as well as the control system of the first embodiment with the SAN filter. The configuration with the SAN filter is more advantageous in terms of calculation amount.

  As described above, the present invention generates a reference signal from the resonance frequency signal of the engine, generates an excitation force in the excitation device based on the signal obtained from the device that detects vibration and the reference signal, Control is performed to reduce the vibration generated at a predetermined position in the vehicle, and further, the signal is acquired by a device that detects vibration, and the resonance frequency is corrected by frequency analysis, so cranking vibration when idling stops, etc. Can be effectively reduced.

In the above-described embodiment, one or two ACMs are provided as a vibration device for applying a vibration force, but three or more ACMs may be provided. The vibration device is not limited to the ACM, and may be an active mass damper or a torque rod type. The place where the vibration device is provided is not limited to the lower part of the engine, but may be provided between the suspension device and the vehicle body. By providing the vibration device between the suspension device and the vehicle body, the vibration of the vehicle can be reduced.
In the embodiment described above, the filter coefficient update processing of the adaptive filter is performed using the LMS algorithm. For the filter coefficient update processing, a complex LMS algorithm (Complex Least Mean Square Algorithm), a Normalized LMS algorithm (Normalized LMS algorithm) is used. Least Mean Square Algorithm), Projection Algorithm, SHARF Algorithm (Simple Hyperstable Adaptive Recursive Filter Algorithm), RLS Algorithm (Recursive Least Square Algorithm), FLMS Algorithm (Fast Least Mean Square Algorithm), Legal Filter Using DCT ( Can use various algorithms such as Adaptive Filter using Discrete Cosine Transform, SAN Filter (Single Frequency Adaptive Notch Filter), Neural Network, Genetic Algorithm, etc. Needless to say.

3a, 3b ACM
4 Steering 5 Engine mount 9, 9a, 9b Sensor 10 Vehicle 11 Control device 12 Engine 13 Seat 14 Car body 16, 21 Synthesizer 17, 22, 25, 33, 34 Adaptive filter 18, 23, 24, 26, 27, 37, 39 LMS calculation unit 31 Cosine wave generator 32 Sine wave generator 35, 36, 38 Adder

Claims (3)

At least one vibration generating device that generates a vibration force, a device that detects vibration at a predetermined position in the vehicle, and a reference signal whose signal frequency is a real number multiple of the resonance frequency of the power source, and detects the vibration Vibration of a vehicle comprising a control device that controls the vibration generating device to generate a vibration force based on a signal obtained from the device and the reference signal to reduce vibration generated at a predetermined position in the vehicle A reduction system,
The control device monitors a signal from a device that detects the vibration, and corrects the resonance frequency by frequency analysis when a deviation of the resonance frequency is detected.   The vehicle vibration reduction system according to claim 1, wherein the vibration exciting device is provided between a suspension device and a vehicle body. At least one vibration generating device that generates a vibration force, a device that detects vibration at a predetermined position in the vehicle, and a reference signal whose signal frequency is a real number multiple of the resonance frequency of the power source, and detects the vibration Vehicle in a system comprising a control device that controls the vibration generating device to generate a vibration force based on a signal obtained from the device and the reference signal so as to reduce vibration generated at a predetermined position in the vehicle A vibration reduction method of
The processing procedure of the control device is as follows:
Monitoring a signal from a device detecting the vibration;
A step of correcting the resonance frequency by frequency analysis when a deviation of the resonance frequency is detected;
A vehicle vibration reduction method comprising:

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