Patent Translate Powered by EPO and Google Notice This translation is machine-generated. It cannot be guaranteed that it is intelligible, accurate, complete, reliable or fit for specific purposes. Critical decisions, such as commercially relevant or financial decisions, should not be based on machine-translation output. DESCRIPTION JP2004020714 The present invention provides an active vibration noise reduction device that can be realized by an inexpensive microcomputer or the like without using an expensive DSP or the like in order to reduce vibration noise of a rotational secondary component in a 4-cycle 4-cylinder engine. An active vibration noise is generated by updating an adaptive notch filter coefficient of an adaptive notch filter 4 by adaptive processing and canceling vibration noise by a secondary vibration noise generator 8 driven based on an output of the adaptive notch filter 4. In the reduction device, a pulse wave synchronized with the rotational secondary component of the 4-cycle 4cylinder engine 21 is generated by the tacho pulse generator 22, and this pulse wave is formed by an analog circuit with the low pass filter 23 and the first phase shift. The reference cosine wave signal and the reference sine wave signal are obtained by filtering in the second phase shifter 25 and the second phase shifter 25. [Selected figure] Figure 1 Active vibration noise reduction device The present invention relates to an equal phase and an anti-phase to vibration noise such as unpleasant engine vibration or engine squeaking (noise) generated in a vehicle interior as the engine rotates. More specifically, the present invention relates to an active vibration noise reduction device that can be realized by an inexpensive microcomputer or the like without using an expensive DSP or the like. [0002] Since the engine muddy sound is a vibration radiation sound generated by transmitting the excitation force generated by the engine rotation to the vehicle body, the vibration having remarkable periodicity synchronized with the number of rotations of the engine The noise is noise. For example, in the case of a four-stroke four-cylinder engine, a large amount of vibration noise, which is called a rotational secondary component having a frequency twice as high as the engine rotation speed, is generated. [0003] This is because torque fluctuation due to gas combustion that occurs every half rotation of the engine crank generates 10-04-2019 1 excitation vibration originating from the engine, and this causes vibration noise in the vehicle interior. When this rotational secondary component coincides with the cavity resonance frequency of the vehicle body, a particularly loud noise is generated in the vehicle interior, causing discomfort to the occupants. Among such engine noises, a method using an adaptive notch filter as proposed in, for example, Japanese Patent Laid-Open No. 2000-99037 is known as a method for actively reducing the rotational secondary component most likely to be a problem. ing. The configuration of the active vibration noise reduction device disclosed therein is shown in FIG. In FIG. 5, all discrete operations for realizing the active vibration noise reduction device are processed by the DSP 17. First, noise and the like superimposed on the engine pulse are removed by the waveform shaper 1 and the waveform is shaped. The output signal of this waveform shaper 1 is applied to a cosine wave generator 2 and a sine wave generator 3 to produce a cosine wave and a sine wave as reference signals. The output signal of the coefficient multiplier 5 that multiplies the reference cosine wave signal that is the output signal of the cosine wave generator 2 and the filter coefficient W0 of the adaptive notch filter 4 is a reference sine wave signal that is the output signal of the sine wave generator 3 And the filter coefficient W 1 of the adaptive notch filter 4 are added by the adder 7 at the output signal of the coefficient multiplier 6 and supplied to the secondary vibration noise generator 8. The secondary vibration noise is generated by the secondary vibration noise generator 8 and is canceled by interfering with the vibration noise based on the engine pulse. At this time, the residual signal that can not be silenced is used as an error signal e in the adaptive control algorithm. On the other hand, at the notch frequency to be muffled determined from the engine speed, a reference cosine wave is transferred to the transfer element 9 having C 0 simulating the transfer characteristic from the output of the adaptive notch filter 4 to the adaptive control algorithm calculator 15. A reference sine wave signal is supplied to the transfer element 10 which supplies a signal and has C1 simulating the transfer characteristic from the output of the adaptive notch filter 4 to the adaptive control algorithm calculator 15 as well, and outputs the transfer element 9 and the transfer element 10 Are added by the adder 13 and the error signal e are supplied to the adaptive control algorithm computing unit 15, and the filter coefficient W0 of the adaptive notch filter 4 is updated based on the adaptive control algorithm, for example, the LMS algorithm. Similarly, a reference sine wave signal is supplied to the transfer element 11 having C0 simulating the transfer characteristic from the output of the adaptive notch filter 4 to the adaptive control algorithm computing unit 16 at the notch frequency to be muffled determined from the engine speed Similarly, the reference cosine wave signal is supplied to the transfer element 12 having (-C1) simulating the transfer characteristic from the output of the adaptive notch filter 4 to the adaptive control algorithm computing unit 16, and the outputs of the transfer element 11 and the transfer element 12 Are added by the adder 14 and the error signal e to the adaptive control algorithm computing unit 16, and the filter coefficient W1 of the adaptive notch filter 4 is updated based on the adaptive control algorithm, for example, the LMS algorithm. In this manner, the filter coefficients W 0 and W 1 of the adaptive notch filter 4 10-04-2019 2 recursively converge to an optimal value so that the error signal e becomes smaller, in other words, the vibration noise in the vibration noise suppression unit is reduced. I will. SUMMARY OF THE INVENTION The above-mentioned active vibration noise reduction device according to the prior art is realized by discrete signal processing. In order to output a muffling signal as an active vibration noise reduction device, multiplication of the reference cosine wave signal and the filter coefficient W0 of the adaptive notch filter 4, multiplication of the reference sine wave signal and the filter coefficient W1 of the adaptive notch filter 4, and Two multiplications such as addition and one addition are required. On the other hand, in order to perform adaptive processing, r0 can be obtained by multiplying the reference cosine wave signal and the transfer characteristic C0, multiplying the reference sine wave signal and the transfer characteristic C1, and performing addition and two additions such as addition and one addition. Similarly, r1 can be determined by two multiplications and one addition. In addition, since two multiplications and one addition are required in the LMS algorithm operation, eventually, eight multiplications and four additions are required for the adaptive processing alone. [0010] A total of 10 multiplications and 5 additions must be performed within the discrete sampling period. This has the advantageous aspect that the amount of calculation is very small compared to the long tap length adaptive filter used in realizing general non-periodic active noise and vibration control. On the other hand, although a specific method for generating the reference cosine wave signal and the reference sine wave signal is not shown, generally, the period of the vibration noise generated from the engine rotational speed is calculated. For sampling values at each sampling time of a cosine signal or a sine signal based on a period, a method is used in which a cosine function or a sine function is calculated with a Taylor-expanded polynomial. Shown below is a polynomial by Taylor expansion of cosine function and sine function. 【 ００１１】 ｃｏｓ（ｘ）＝１−ｘ<２>／２！ ＋ｘ<４>／４！ ……＋（−１）<ｎ>・ ｘ<２ｎ>／（２ｎ）！ ｓｉｎ（ｘ）＝ｘ−ｘ<３>／３！ ＋ｘ<５>／５！ ……＋（−１）<ｎ>・ ｘ<２ｎ＋１>／（２ｎ＋１）！ The reference cosine wave signal and the reference sine wave signal are created by obtaining an approximation value by calculation up to a certain constant in the above-described polynomial which actually goes to infinity. As described above, in the apparatus for actively reducing vibration noise of engine rotation second-order components using the conventional adaptive notch filter, a large number of multiplications are required to generate the reference cosine wave signal and the reference sine wave signal. At the same time as the addition is required and the merit of a small amount of operation when the adaptive notch filter is used is reduced, it is indispensable to use an expensive DSP or the like which can perform high-speed operation. Therefore, it has a problem that it is difficult to realize a low-cost active vibration noise reduction device using an inexpensive microcomputer or the like although the calculation speed is low. The present invention solves the above-mentioned conventional problems, and discrete numerical operation for producing a reference cosine wave signal and a reference sine wave signal by using a filter and a phase shifter constituted by an analog circuit. It is an object of the present invention to realize a low-cost active vibration noise reduction device 10-04-2019 3 by eliminating the need to use a microcomputer. According to the present invention for achieving the above object, there is provided a synchronous pulse generator for generating an electrical pulse synchronized with a frequency to be a subject of vibration noise generated from a vibration noise source, A cosine wave generating means for generating a cosine wave synchronized with the generated pulse signal from the synchronous pulse generator, and a reference cosine wave signal and a reference sine wave signal synchronized with the generated cosine wave from the cosine wave generating means and orthogonal to each other Means for generating a reference signal, an adaptive notch filter to which the reference cosine wave signal and the reference sine wave signal from the reference signal generating means are input, and vibration noise driven by an output signal from the adaptive notch filter A secondary vibration noise generator generating secondary vibration noise that cancels out the residual noise signal due to the interference between the vibration noise and the secondary vibration noise, the reference cosine wave signal, and Coefficient updating means for updating the filter coefficient of the adaptive notch filter by the correction signal of the reference sine wave signal, the coefficient from the output of the adaptive notch filter of the reference cosine wave signal and the reference sine wave signal to form the correction signal In an active vibration noise reduction device comprising simulated transfer characteristic correction means for simulating transfer characteristics up to the input of the updating means, the cosine wave generation means is a low pass filter or a band pass filter constituted by an analog circuit. It is characterized by The active vibration noise reduction device having the above configuration is characterized in that the cosine wave generation means is a low pass filter or a band pass filter formed of an analog circuit, whereby discrete numerical operation is performed. It is possible to generate a cosine wave as a reference signal for generating the reference cosine wave signal and the reference sine wave signal without requiring any The effect is obtained that the device can be used. In the above configuration, the reference signal generating means is a first phase shifter composed of an analog circuit to which the generated cosine wave as an output signal from the cosine wave generating means is input, and the same as the cosine wave generating means. And a second phase shifter composed of an analog circuit to which the generated cosine wave, which is an output signal from the above, is input, thereby eliminating the need for any discrete numerical operation. It is possible to generate the reference cosine wave signal and the reference sine wave signal, and it is possible to obtain an effect that a discrete arithmetic processing unit having a low calculation speed can be used in realizing the active vibration noise control apparatus. In addition, the synchronous pulse generator has a feature of outputting a pulse synchronized with the ignition cycle of the engine, so that it is possible to obtain a pulse synchronized with the ignition cycle identical to the gas combustion cycle. The advantage is obtained that it is easy to generate a reference signal synchronized with the vibration caused by the gas combustion of the engine. The synchronous pulse generator is characterized by being a tach pulse generator or a TDC sensor, and these are devices that are already equipped in vehicles, and there are vibrations that become a problem by using them. The effect is obtained 10-04-2019 4 that it is possible to eliminate the need to separately install a device that generates an electrical pulse synchronized with the frequency of noise. BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings for understanding of the present invention. The same components as those of the conventional active vibration noise reduction device shown in the prior art are designated by the same reference numerals. FIG. 1 is a block diagram showing the configuration of the active vibration noise reduction device according to the present embodiment, and 21 is a 4-cycle 4-cylinder engine as a vibration noise source. It operates to reduce the rotational secondary component in the vibration noise generated from the cycle 4 cylinder engine 21. Generally, among the rotational secondary components in the four-cycle four-cylinder engine, vibration noise (hereinafter referred to as secondary task vibration noise) in a specific frequency range is often a problem. A TDC sensor (top dead center sensor) as a synchronous pulse generator or a tacho pulse generator 22 (hereinafter referred to as a tacho pulse generator) is used as a rotational secondary component of a 4-cycle 4-cylinder engine 21 as a vibration noise source. It generates a tacho pulse signal which is a synchronized signal. In many cases, the tach pulse signal is already provided on the vehicle side as an input signal of the tachometer, etc. There is no need to separately install a device for generating an electric pulse synchronized with the frequency of the vibration noise which is a special problem. The tach pulse signal in the four-stroke four-cylinder engine 21 is a pulse wave of two cycles per one rotation of the crank, and hence is a signal synchronized with the rotational secondary component of the four-stroke four-cylinder engine 21. A tacho pulse signal which is an output signal from the tacho pulse generator 22 is input to a low pass filter 23 as cosine wave generating means constituted by an analog circuit. Since the tach pulse signal is a pulse signal synchronized with the rotational secondary component of the 4-cycle 4-cylinder engine 21 as described above, the tacho pulse signal is composed of the sum of a component having the rotational secondary component as a fundamental frequency and its harmonic components There is. Therefore, by inputting a tacho pulse signal to the low pass filter 23 set so that the pass frequency band is the second-order task vibration noise frequency, only cosine waves having a frequency equal to the frequency of the second-task vibration noise are extracted It becomes possible. FIG. 2 is an example of a filter used as the low pass filter 23. This filter is called a second-order positive feedback low-pass filter, and is composed of terminals 27, 33, resistors 28, 29, capacitors 30, 31 and an operational amplifier 32. The frequency characteristic of this filter is determined by the values of the resistors 28, 29 and the capacitors 30, 31, and the frequency above the cutoff frequency has a characteristic that the level decreases with a slope of 12 dB / oct. The cosine wave, which is an output signal from the low pass filter 23, is a reference signal generating means similarly constituted by an analog circuit and a first phase shifter 24 as a reference signal generating means constituted by an analog circuit. Are input to the second phase shifter 25. FIG. 3 shows an example of the phase shifter used in the present embodiment. This phase shifter is called a first-order phase shifter using an operational 10-04-2019 5 amplifier, and comprises terminals 34 and 40, resistors 35, 36 and 37, a capacitor 38 and an operational amplifier 39. An example of the phase characteristic of this phase shifter is shown in FIG. The phase characteristic of this phase shifter is a characteristic in which the phase of the output signal is delayed with respect to the input signal. Here, at the secondary task vibration noise frequency, the phase characteristic of the first phase shifter 24 is set to advance by π / 2 [rad] with respect to the phase characteristic of the second phase shifter 25. That is, if the output signals of the first phase shifter 24 and the second phase shifter 25 are relatively viewed, the output signal of the first phase shifter 24 is a cosine wave having a frequency equal to the secondary task vibration noise frequency. It can be said that the output signal of the second phase shifter 25 is a sine wave having a frequency equal to that of the secondary task vibration noise frequency. Therefore, in the active vibration noise reduction device shown in FIG. 1, the output signal of the first phase shifter 24 is a reference cosine wave signal, and the output signal of the second phase shifter 25 is a reference sine wave signal. In this way, the reference cosine wave signal and the reference sine wave signal obtained only by analog signal processing without performing discrete operation processing are respectively quantized by the microcomputer 26 that processes the discrete operation, and discrete operation processing is performed. Used as numerical data for The arithmetic processing after the reference cosine wave signal and the reference sine wave signal as discrete numerical data are obtained is the same as that shown in the prior art. That is, the output signal of the coefficient multiplier 5 that multiplies the reference cosine wave signal by the filter coefficient W 0 of the adaptive notch filter 4 is the coefficient multiplier 6 of the coefficient multiplier 6 that multiplies the reference sine wave signal by the filter coefficient W 1 of the adaptive notch filter 4. The output signal is added by the adder 7 and supplied to the secondary vibration noise generator 8. The secondary vibration noise is generated by the secondary vibration noise generator 8 and is canceled by interfering with the subject vibration noise generated from the vibration noise source. At this time, the residual signal that can not be silenced is used as an error signal e in an adaptive control algorithm described later. On the other hand, at the notch frequency to be muffled determined from the engine speed, a simulated transfer having C 0 simulating the transfer characteristic from the output of the adaptive notch filter 4 to the adaptive control algorithm computing unit 15 as coefficient updating means A reference cosine wave signal is supplied to the transfer element 10 having C1 that simulates the transfer characteristic from the output of the adaptive notch filter 4 to the adaptive control algorithm computing unit 15 by supplying the reference cosine wave signal to the transfer element 9 as characteristic correction means. The correction signal r0 and the error signal e obtained by adding the outputs of the transfer element 9 and the transfer element 10 in the adder 13 are supplied to the adaptive control algorithm computing unit 15, and adaptation is performed based on the adaptive control algorithm, for example, LMS algorithm. The filter coefficient W0 of the notch filter 4 is updated. Similarly, a reference sine wave signal is supplied to the transfer element 11 having C0 simulating the transfer characteristic from the output of the adaptive notch filter 4 to the 10-04-2019 6 adaptive control algorithm computing unit 16 at the notch frequency to be muffled determined from the engine speed Similarly, the reference cosine wave signal is supplied to the transfer element 12 having (-C1) simulating the transfer characteristic from the output of the adaptive notch filter 4 to the adaptive control algorithm computing unit 16, and the outputs of the transfer element 11 and the transfer element 12 Are added by the adder 14 and the error signal e to the adaptive control algorithm computing unit 16, and the filter coefficient W1 of the adaptive notch filter 4 is updated based on the adaptive control algorithm, for example, the LMS algorithm. . At this time, in the case of the LMS algorithm, the filter coefficients W 0 (n + 1) and W 1 (n + 1) of the adaptive notch filter 4 are obtained by the following equations. W0 (n + 1) = W0 (n) -μ · e (n) · r0 (n) (1) W1 (n + 1) = W1 (n) −μ · e (n) · r1 (n) (2) where μ is a step size parameter. In this manner, the filter coefficients W 0 and W 1 of the adaptive notch filter 4 recursively converge to an optimal value so as to reduce the vibration noise in the vibration noise suppression unit so that the error signal e becomes smaller. I will. As described above, the active vibration noise reduction device described in the present embodiment is inexpensive because it does not require any discrete arithmetic processing at all when generating the reference cosine wave signal and the reference sine wave signal. A slow microcomputer can be used as a discrete arithmetic processing device, and an active vibration noise reduction device can be configured at low cost to reduce the vibration noise of the rotational secondary component of the 4-cycle 4cylinder engine. In this embodiment, the cosine wave generation means is the low pass filter 23 formed of an analog circuit, but may be a band pass filter formed of an analog circuit. Absent. Also in this case, the band pass filter is set so that the pass frequency band is the secondary task vibration noise frequency, and the same effect can be obtained by extracting only cosine waves having a frequency equal to the frequency of the secondary task vibration noise. In the present embodiment, the reference signal generating means is the first phase shifter 24 and the second phase shifter 25. However, the differentiator calculated in the microcomputer 26 It does not matter. In this case, data obtained by quantizing the cosine wave output from the low pass filter 23 by the microcomputer 26 is used as a reference cosine wave signal, and the difference between this reference cosine wave signal and the reference cosine wave signal one sample before is The same effect is achieved by using the obtained differential signal as a reference sine wave signal. In the present embodiment, the output signal of the synchronous pulse generator 22 is a tach pulse signal, which occurs every 180 degrees of crank angle (in the case of a 4-cycle 4cylinder engine). It may be a TDC sensor signal. In this case, the signal input to the low pass filter 23 is synchronized with the rotational secondary component of the four-stroke four-cylinder engine 21 and is a pulse wave having a duty of 50% with two cycles per one crank rotation. With this configuration, in addition to the effects of the above embodiment, since the TDC sensor signal does not include even-order components in the harmonic components having the rotational secondary component as the fundamental frequency component, the low-pass filter 23 An effect is obtained that low-order ones can be used. 10-04-2019 7 Further, in the present embodiment, the case where the secondary vibration noise generator is applied to an engine muffled sound reduction device in which the speaker is a speaker is shown, but the secondary vibration noise generator is an electronic control mount device and an engine The present invention is also applicable to vibration reduction devices, commonly known as Active Engine Mount devices. As described above, according to the present invention, the reference cosine wave signal and the reference sine wave signal can be generated without requiring any discrete numerical operation. A cosine wave can be generated, and in realizing an active vibration noise control device, a discrete arithmetic processing device with a low calculation speed can be used, and an effect that an inexpensive microcomputer can be used can be obtained. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a configuration of an active vibration noise reduction device according to an embodiment. FIG. 2 is a block diagram showing the configuration of a low pass filter in the above configuration. FIG. 3 is a block diagram showing the configuration of a phase shifter in the above configuration. FIG. 4 is a graph showing phase characteristics of the same phase shifter. FIG. 5 is a block diagram showing the configuration of a conventional active vibration noise reduction device. [Description of the code] 4 adaptive notch filters 5, 6 coefficient multipliers 8 secondary vibration noise generators 9, 10, 11, 12 transfer elements (simulated transfer characteristic correction means) 15, 16 adaptive control algorithm arithmetic unit (coefficient update means ) 21 4-cycle 4cylinder engine 22 Tach pulse generator (synchronous pulse generator) 23 low pass filter (cosine wave generator) 24 first phase shifter (reference signal generator) 25 second phase shifter (reference) Signal generation means) 26 microcomputer 10-04-2019 8

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