CN203547837U - Engine noise reduction controller - Google Patents

Abstract

An engine noise reduction controller includes a DSP data processing module, a power amplification module connected to an audio decoding module that can output an anti-phase amplitude modulation output signal to offset engine noise, and an engine connected to the DSP data processing module that can receive an engine speed signal Speed regulation module. The utility model collects the noise signal through the DSP, analyzes the signal, outputs the reverse sound wave equal to the external noise, and neutralizes the noise, so as to achieve the effect of noise reduction. This method can reduce the quality of the whole vehicle and at the same time weaken the damage to the human body. Larger low-frequency noise, better noise reduction effect, so as to realize the low noise of the whole vehicle.

Description

An engine noise reduction controller

technical field

The utility model belongs to the technical field of automobile electronics, in particular to an engine noise reduction controller.

Background technique

The engine is the excitation source of the entire noise system, and the engine noise reduction technology can be roughly divided into active noise reduction and passive noise reduction. Active noise reduction is to directly reduce engine noise, while passive noise reduction needs to increase the system's resonance frequency and sound absorption and noise reduction as much as possible. The traditional engine noise control technology is mainly passive noise reduction technology, including sound absorption treatment, sound insulation treatment, use of mufflers, damping and vibration reduction, etc. This method will cause the car to be bulky and the noise reduction effect is not ideal, and there is no active noise reduction treatment for the engine. .

Utility model content

The purpose of this utility model is to provide an engine noise reduction controller for the above problems.

The technical solution adopted by the utility model is: it includes a data acquisition module for inputting engine noise signals, an audio decoding module connected with the data acquisition module, a DSP data processing module connected with the audio decoding module, and a DSP data processing module connected with the audio decoding module. A power amplifying module that can output anti-phase amplitude modulation output signals to offset engine noise and an engine speed conditioning module that is connected with the DSP data processing module and can receive engine speed signals.

Further, the audio decoding module is an audio codec CODEC.

Further, the DSP data processing module is connected with an engine speed regulation module capable of receiving engine speed signals.

Further, the engine speed regulating module includes a magnetoelectric speed sensor and a regulating circuit.

Further, the DSP data processing module is connected with a FLASH ROM expansion module and an SDRAM expansion module that can expand the on-chip capacity of the DSP data processing module.

Further, the data acquisition module is a left and right channel microphone connected to the audio decoding module.

Furthermore, the power amplifying module includes a class D power amplifier connected to the audio decoding module and a speaker connected to the class D power amplifier.

The utility model collects the noise signal through DSP, analyzes the signal, outputs the reverse sound wave equal to the external noise, and neutralizes the noise, so as to achieve the effect of noise reduction. This method can reduce the quality of the whole vehicle and at the same time weaken the noise The low-frequency noise that damages the human body is more effective, and the noise reduction effect is better, so as to realize the low noise of the whole vehicle.

Description of drawings

Fig. 1 is the structural representation of the utility model.

Detailed ways

The utility model will be further described in detail below in conjunction with the accompanying drawings and specific embodiments to facilitate a clear understanding of the utility model, but they do not limit the utility model.

As shown in Figure 1, the utility model is installed in the engine intake manifold, including data acquisition module 1, audio decoding module 2, DSP data processing module 3 and power amplification module 4, and data acquisition module 1 is connected with audio frequency decoding module 2 , the DSP data processing module 3 is connected to the audio decoding module 2, and the power amplification module 4 is connected to the audio decoding module 2. The data collection module 1 is the microphone of the left and right sound channels connected with the audio decoding module. The audio decoding module 2 is an audio codec CODEC. The DSP data processing module 3 is connected with an engine speed regulating module 5, and the engine speed regulating module 5 includes a magnetoelectric speed sensor and a regulating circuit; the DSP data processing module 3 is connected with a FLASH ROM expansion module with an expandable DSP data processing module 3 internal capacity. 6 and SDRAM expansion module 7. The power amplifying module 4 includes a class D power amplifier 4.1 connected to the audio decoding module and a speaker 4.2 connected to the class D power amplifier 4.1.

Data acquisition module: The engine noise is input through the signal microphone MIC of the left and right channels, and it is installed in the engine compartment. When selecting a microphone, it is required that it can detect low-frequency noise (100-1000Hz) in the environment that can be heard by the ear.

DSP data processing module: It can collect noise below 1.5KHZ frequency and the sampling frequency is greater than or equal to 16KHZ. The function of this module is to collect data, integrate and process the control algorithm, and realize real-time operation to control the noise. Since the on-chip capacity of DSP is not enough, this module also includes FLASH ROM expansion module and SDRAM expansion module.

Audio codec module: This module can choose CODEC, a low-power, stereo audio codec. The noise signals of the differential left and right channels input by the microphone are processed by the audio decoder, processed by the DSP data processing module, and then the signal is input to the power amplification module for further processing.

Power amplifying module: use Class D power amplifier as the core of the power amplifying module in this controller, which can amplify the signal output by the audio codec module, and finally obtain a stereo sound with the opposite phase and the same amplitude as the noise, and then use the speaker to amplify the sound Emitted to cancel out the original noise.

Engine speed conditioning module: The engine speed conditioning module is composed of a magnetoelectric speed sensor and a conditioning circuit. The conditioning circuit compares the sine wave speed signal output by the magnetoelectric speed sensor across zero, and obtains a square wave signal after being processed by the conditioning circuit. DSP The data processing module directly collects the digital signal.

The working principle of the utility model: the engine noise signal is input through the signal microphone MIC of the left and right channels, and after the signal is processed by the audio decoding module, it is input to the DSP data processing module as the target signal to be eliminated; at the same time, the DSP data processing module receives After the engine speed signal, the half-order noise frequency at this speed is calculated as the reference signal of the active noise reduction system, and the signal collected by the microphone to the DSP data processing module is used as the target signal to be eliminated, and an adaptive filter is designed to input For each sample value of the reference signal, update and adjust the weighting coefficient according to a specific algorithm, so that the mean square error between the output of the filter and the target signal is minimized, and the output of the filter thus obtained is used as the final reverse amplitude modulation signal Then the speaker output is driven by the audio decoding module and the class D power amplifier to offset the engine noise.

The content not described in detail in this specification belongs to the prior art known to those skilled in the art.

Claims (6)

1. a kind of engine noise reduction controller is characterized in that: it comprises the data acquisition module that is used for engine noise signal input, the audio decoding module that is connected with data acquisition module, the DSP data processing module that is connected with audio frequency decoding module, and The audio decoding module is connected to a power amplification module that can output anti-phase amplitude modulation output signals to offset engine noise, and an engine speed conditioning module that is connected to the DSP data processing module and can receive engine speed signals. 2. An engine noise reduction controller according to claim 1, characterized in that: the audio decoding module is an audio codec CODEC. 3 . The engine noise reduction controller according to claim 1 , wherein the engine speed regulating module includes a magnetoelectric speed sensor and a regulating circuit. 4 . 4. A kind of engine noise reduction controller according to claim 1, characterized in that: said DSP data processing module is connected with a FLASHROM expansion module and an SDRAM expansion module which can expand the internal capacity of the DSP data processing module. 5 . The engine noise reduction controller according to claim 1 , wherein the data acquisition module is a left and right channel microphone connected to an audio decoding module. 5 . 6 . The engine noise reduction controller according to claim 1 , wherein the power amplifying module includes a class D power amplifier connected to the audio decoding module and a speaker connected to the class D power amplifier.

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