Speaker placement solutions
NXP
Reference website: https://www.nxp.com.cn
NXP Semiconductors has announced the launch of a solution for echo cancellation and noise reduction, the solution significantly reduces the noisy voice communication problems, and car manufacturers to provide consumer satisfaction hands-free calling experience. This cost-effective solution that combines innovative ECNR software, which can be easily ported to NXP car radio and audio DSP processing or i.MX family of applications processors. The new NXP ECNR solutions to improve voice quality by eliminating echo and filter unwanted noise in the cockpit.
Echo and noise make conversation difficult way to travel. Speakers in the car at the time of the speech signal transmitting incoming phone call will have an echo, echo returns to the microphone can cause callers to hear his own voice, so that distraction and can lead to interruption of communication. In addition, the road noise from the fan, exhaust pipes, tires, windows and passengers may penetrate call, causing the call does not recognize, call the ultimate driving experience damage and annoyance.
The new NXP ECNR solution solves both problems by eliminating echo and filter unwanted noise in the cockpit, thereby improving call quality.
Sound can affect the comfort of the journey. Traffic noise, music, or even the size of the air conditioner sounds good to say you can bring irritation, at worst, can bring great destructive. Premium Sound System can be canceled out unwanted outside sound, adjust the music according to your requirements; the interior environment can be arbitrary or energetic or calm and soothing.
With wide receiver combination devices and processing audio, broadcast and noise, NXP also offers the most advanced class AB and class D amplifiers for car audio systems. They can offer more channels, high output power and high voltage, it is designed to bring customers maximum flexibility.
NXP car stereo display solutions
TDF853x series provides compatibility channel occupies 3-5
9 speaker system
14 speaker system
17 speaker system
Microphone placed Solutions
Through research I domestic and foreign car company Web site, as well as collecting all the papers on the on-board microphone array microphone placement program are summarized below.
Option One
On youtube to see instructional installation video microphone, Address: https://www.youtube.com/watch?v=PR4LYpvRD6U
And this microphone after query, have to buy on Amazon, address: https://www.amazon.com/Universal-Pioneer-Replacement-Microphone-Navigation/dp/B074FR41Q2
Option II
Mercedes-Benz SL and SLR Roadster> SL Class (R230)
About SL500, SL550, SL600, placed source: https://mbworld.org/forums/sl-class-r230/749916-where-correct-position-microphone.html
R230s There are two types of microphones
- Placing a microphone (Figure 1) in the rear view mirror
- SOS switch placed beside a microphone, which is placed after SOS housing (Figure 2)
third solution
On youtube to see another microphone placement scheme, Bluetooth microphone is in the upper left corner of the navigation screen, the video talked about, so installation is not conducive to the radio microphone.
Option IV
Microphone placement Source: https://www.smartcarofamerica.com/threads/bluetooth-mic-placement.15972/
Program V
The car's microphone is generally in your glasses case above that, which is that the roof of the dome there in the control of
Tesla model of microphone positions 3
A model of BMW microphone placement
Sixth aspect
Some models are in the driver's side of the roof trim, a gray rubber rectangle. There are some generally has a small hole marked mic is a microphone, mostly unlabeled.
Program VII
Microphone placed next to the door
Program eight
This is an 8-board microphone array of Bluetooth products, product Address: https://www.theverge.com/2019/8/6/20754404/amazon-echo-auto-review-alexa-car-price-specs-features
Product Description Address: https://www.wired.com/story/amazon-echo-auto-engineering/
Program nine
NTT-TX solutions provided by the company , most car drivers can only capture the voice of the solution to provide voice communications to all passengers; in the car can hear all kinds of loud sounds and reverberation (road noise, car audio Wait)
solution:
- Beamforming seat by any smart microphone
- Original whistle control technology
- Reverb control technology
- Enclosed environment having a plurality of microphones and speakers echo cancellation (about 30dB reduces echoes)
advantage:
- Picks up sound from any seat in the car accurately
- Can improve speech recognition in noisy environments
- Completely hands-free
- By eliminating background noise to improve sound quality on-board microphone
Program X
Si Spitzer annular ring 6 and the microphone array microphone array 6 + 1
Bose microphone array Solution
Program eleven
This microphone array solution is seen in the paper, Acoustic Noise and Echo Canceling with Microphone Array
Providing on-board audio solutions company
I love the program Net IFLYTEK held in 2016 iFly Intelligent Voice Contest
Application microphone array technology in the automotive cockpit voice enhancement system
A typical system block diagram CSE, in order to reduce unwanted noise, a processor to perform active noise reduction (ANC) algorithm .
Microphone arrays capture sound and the audio signal create the inverted fine determined, and then sent to an amplifier, speakers and the subwoofer drive system, does not affect the volume of music or talk to reduce low frequency noise of the car cabin.
In order to enhance the sound of the engine, the processor executes an engine sound enhancement (ESE) or sound algorithm execution process is determined by a stereo system, and the RPM of the engine load, the engine sound playing pre-recorded, or so that capture sound signals from the microphone array Transmission The processor amplification and tuning this sound signals to let drivers on the engine sound is not objectionable.
The processor implements the microphone beamforming algorithm (MBF ), in order to efficiently perform high-performance handsfree system. The driver's face from the microphone to the sound beam, the system only "hear" present in the beam and reject sound coming from other directions. Very particular from respective microphones in the microphone array system, the sampling frequency by a specified separation. The distance to affect the sound arrival time of each particular microphone spent, provide sufficient information about the direction and distance of the sound source for the system, and reject any sound other than the virtual beams.
Integrated analog front end integrated in the ADC, help to improve the signal to noise ratio (SNR) and achieve higher quality audio capture. However, this method only achieve this goal, one of the many ways. For example, I2S digital microphones may also be used, but this method is higher than the cost of alternative analog microphone and multi-channel ADC. Through this program cost, performance, and other implementations of multi-angle considerations final confirmation, it has a high market advantage!
Strato microphone array solution services Smart Car
Official website: https://www.aicloud.com/dev/ability/index.html?key=sma
News 1: http://digital.it168.com/a2016/0524/2659/000002659296.shtml
News 2: http://www.sohu.com/a/133531831_703174
Function: Voice wake up, the sound source directional far-field noise reduction, echo cancellation, voice interrupted the speech correction, several rounds of dialogue
Advantages: very strong noise immunity, the driver can accurately identify the utterance in the vehicle speed 80km / h of
Car noise: car tire noise, wind noise, the sound of car air conditioning, engine noise and other road noise environment
Strato type anti-noise + speech recognition microphone array car noise easily cracks
principle:
The array may be a multi-microphone sound arrival time difference, accurately calculate the angle and distance between the sound source and the array module, positioning and tracking of a target sound source, and the use of spatial filtering characteristics of the microphone array, are formed in the direction of the target speaker pickup beam, only the beam pick-up signal, suppressing noise and reverberation (reflected sound) other than the beam, while by echo cancellation, filtering out the sound emitted by the audio device, so that the acquired user voice recognition engine sound clearer pure.
Readers see this chart, please listen to me say a few words:
Most are single-vehicle system microphone, high-end cars will configure the microphone array, generally consisting of 2,4,6 microphone microphone array, also explained to me in front of the microphone placed on the market most of the on-board solutions. It can be summarized thus: the design of vehicle microphone, either one, or two or four components a linear array of microphones , or with four or six microphones annular layout (see Bose).
Since the microphone array will inevitably ambient noise pickup driving portion, a voice recognition rate impact, which, considering the physical structure SinoVoice vehicle speed change and the vehicle for driving the vehicle during tire noise, wind noise, the sound of car air-conditioning , engine noise and other ambient noise onboard information modeling, and practical training with a lot of traffic noise data, to further optimize the voice recognition engine, launched a deep acoustic model adaptive learning algorithm and interior noise for noise immunity, so Strato speech recognition with strong noise immunity, easy to deal with common car ambient noise. Meanwhile, the technology uses deep neural network algorithm (DNN) algorithm, the user can use, use by trained accumulated voice data, optimization algorithms and improve speech recognition rates, so that voice interaction of driver and vehicle equipment increasingly more fluent.
Strato far-field voice interaction solutions to fully meet the needs of drivers
In order to fully meet the actual needs of the driver while driving, Strato far-field voice interaction solutions in the realization of phone calls, send text messages, listen to music, maps, navigation, control equipment and other voice control, while providing weather, news for drivers, story, stock, trains, flights, restaurants, and other 30 kinds of cloud information and content services.
In driving, the driver just say wake up words such as "Healer boot" on-board equipment will be turned on, and the formation of a beam pickup driver-oriented direction. The driver said, "for me to navigate to the Tiananmen Square" on-board equipment will automatically route planning and navigation, need to call on the road, the driver can say "call to xx", "Call xx", or directly quote the phone number phone will automatically dial when the phone number identification is incorrect, the driver can easily perform error correction by several rounds of dialogue. I got off the phone, if you want to listen to the song to relax, you can just say "let's first blue and white", "Jay to the first song," or "Play Jay blue and white", automotive equipment can easily identify; If you want to know the latest information, No matter the weather, news, stock still, flight information, just say it, you can easily get from the cloud; if you want to go for a blow, breathe, and without hands, just say "window", the window will automatically fall, the real voice control, the driver's eyes and hands back driving, driving safety escort.
In addition, Strato far-field voice interaction solutions have unique advantages: voice recognition, SinoVoice by using idling, medium speed, high speed, open the window, close the window and air conditioning weak wind, strong winds and other driving conditions massive real data recorded by the line under the ASR engine optimization training, so that voice recognition technology Strato can easily cope with various driving ambient noise, and real-time speech recognition accuracy rate has reached industry-leading level; speech synthesis, speech synthesis Strato providing male, female, cute Boys and other sounds for users to choose to meet the individual needs of different users. Meanwhile, SinoVoice take full account of the current state of network coverage, to provide users with voice interaction service combining local and cloud, even if the car traveling in remote areas without a network, using voice interaction can easily control vehicle equipment.
ALANGO vehicle-based voice and audio technology
Reference website address: http://www.alango.com/solutions-automotive.php
Because of noise and reverberation, car interior acoustic environment face unique challenges. Engine, road, amplitude and frequency spectrum of the noise of wind and rain may suddenly change. Sound hard surfaces will have a strong reflection echo, the echo tail is longer. Alango automotive solutions to overcome these challenges is tailored to deliver superior and pleasing voice and audio quality.
Alango companies were to provide a "hands-free speech enhancement," "enhanced voice recognition", "speech enhancement", "vehicle communications" solution
Alango voice communications package (VCP) is the voice of more than 20 million cars on the road enhancement solutions. Alango VCP clearly hear the voice of the passengers in the car through the car hands-free system (using the vehicle microphone and speaker) by reducing echo and noise and adjust the gain and frequency equalization to ensure.
Glossary
| An adaptive directional microphone (ADM) | Alango using beamforming algorithm, two or more microphones may be placed in the compartment to distinguish between speech and noise adaptive. |
| Echo canceller (AEC) | Alango realized the car class "type 1" full-duplex echo cancellation. Easy to configure and adjust to a different car interiors. |
| Noise suppressor (NS) | Reduce noise in the cabin microphone and loudspeaker signals. Alango High Resolution NS can suppress noise up to 24dB, and will not cause significant speech distortion. |
| Automatic gain control (AGC) and dynamic range compressor (DRC) | Voice balanced microphone and speaker level signals, ensuring legible. Alango AGC techniques may be resistant to environmental noise, and fast equalization signal (~200ms) without increasing ambient noise. |
| Frequency equalizer (EQ) | High resolution can be frequency response of the loudspeaker and microphone fine frequency adjustment. |
| EasyListen™ | Real-time incoming voice slows down the speed, thereby improving the clarity of fast talker, foreign language, email and phone number. |
| Automatic volume and balance (AVQ) | The ambient noise level and spectral modifications loudspeaker signal, provide equal loudness and clarity in variable driving conditions (speed, type of road, rain, window, etc.). |
| Packet loss concealment (PLC) | PLC is a lost or discarded to mask influence of packet technology. PLC object is reconstructed composite signal, so as to cover the missing data received bit stream, to hide transmission losses. |
Alango of sound enhancement package (SRP) can be achieved from the driver to voice communication car rear passengers, while the driver without raising his voice or turned to face the passengers.
The driver's voice is actually played through the speakers. This is achieved by Alango intercom package that combines feedback cancellation and noise reduction. Because the driver can naturally exchange, while keeping sight on the road, so it has absolute value in terms of safety and convenience.
Glossary
| Acoustic feedback cancellation (AFC) | Attempts to simulate the acoustic path between the loudspeaker and microphone, and subtracting the feedback signal to predict the prediction value from the microphone signal. |
| Noise suppressor (NS) | Reduce noise in the cabin microphone and loudspeaker signals. Alango High Resolution NS can suppress noise up to 24dB, and will not cause significant speech distortion. |
| Reducing acoustic feedback | Reducing the acoustic feedback can be detected and reducing the feedback, and helps the normal operation of AFC. It is based on the frequency notch filter and adaptive scaling. |
| Automatic volume and balance (AVQ) |
Automatically modifying system amplification and frequency equalizer to compensate for ambient noise intensity and spectral changes. |
Car hands-free digital array microphones and noise reduction solutions provided by ANDREA
Reference website address: https://andreaelectronics.com/products/
Array microphones on the vehicle platform Transtron
Reference website: https://www.transtron.com/en/products/arrayindex.html
Transtron has developed a compact digital array microphone for automotive applications. It uses our unique array microphone technology, which can effectively eliminate noise and pass a driver's voice.
The microphone array used for the eCall
A digital array microphone, includes a speaker which supports the eCall emergency call system, the system has been launched in Russia. Its newly developed high-performance echo canceller can be appropriately processed within the compact housing echo speaker. The design and implementation of the eCall system call quality required in a small space.
The microphone array module may be integrated into the vehicle-mounted device, such as a car navigation system. It has two microphones and high-speed digital signal processor (DSP) is mounted on a miniature circuit board, it can easily be added to our digital array microphone-vehicle device and high quality. It also supports the extended function, such as an echo canceller for a call or input from the external microphone.
Extra
I have this blog is to introduce foreign companies, of course, our domestic IFLYTEK, elephant sound department, etc. are doing well, I will not introduce here, the other for everyone to share a microphone 6 + 1 article array https://www.jianshu.com/p/1cfa15eaadfe
American TI company can eliminate 512 channels of echo signals simultaneously based Telinnovation proposed for the echo canceller AEC solve the problem,
Canada Octasic's developed OTC9600 can achieve good acoustic echo control and adaptive noise reduction.
Huawei, Tencent, IFLYTEK other companies and Tsinghua University, Southwest Jiaotong University and other research institutions to study the echo cancellation problem with cutting-edge technology products.