“In the automotive cockpit electronics market, as automakers strive to differentiate their vehicles from their competitors, an increasingly obvious trend is that audio, voice, and acoustic-related applications are growing rapidly. For example, intelligent voice interaction has become the current mid-to-high end The general configuration of electric vehicles. Car audio is developing from a pure entertainment system in the past to signal input, triggering, processing and feedback, and is beginning to be closely integrated with the car driving experience.
The driving force for the development of the automotive industry is currently shifting from supply-side product-driven to consumer demand-driven. According to Roland Berger’s report, consumers’ definition of automobiles will evolve from “travel tools” to “third space”. Vehicles need to be more proactive in understanding customer needs. This is the general trend of automobile intelligence. From the perspective of intelligent development route, intelligent cockpit and intelligent driving are the two main evolution directions. Integrating supply and demand factors, smart cockpits are expected to become one of the first areas to develop under the wave of automotive intelligence.
According to the IHS report, the car cockpit has gone through the mechanization and Electronic (traditional cockpit) stages. The traditional cockpit system is dominated by simple hardware. The body electronics such as instrumentation, audio and electric seats together form the hardware system of the traditional car cockpit. As for the smart cockpit, with the improvement of functions, its hardware system composition will become more complicated. In the system design of a more complex smart cockpit, the first thing that will be faced is how to efficiently connect various smart nodes? This is also a technical point that traditional automotive electronic system technology provider ADI has exerted in recent years. Its audio bus technology (A2B) and vehicle camera and video bus (C2B) have achieved successful iterations of several generations of products, and have won the OEMs. The wide range of applications.
Changes in consumer demand for automobiles (data source: Roland Berger)
Innovative audio bus realizes audio connection revolution and empowers cockpit voice intelligence
In the automotive cockpit electronics market, as automakers strive to differentiate their vehicles from their competitors, an increasingly obvious trend is that audio, voice, and acoustic-related applications are growing rapidly. For example, intelligent voice interaction has become the current mid-to-high end The general configuration of electric vehicles. Car audio is developing from a pure entertainment system in the past to signal input, triggering, processing and feedback, and is beginning to be closely integrated with the car driving experience.
There will be more and more audio devices in the car, and the audio quality will get better and better. Almost all emerging applications require multiple acoustic sensors (such as microphones or microphone arrays) to achieve the best system-level performance, so a simple But cost-effective interconnection technology ensures that the total system cost is minimized. To coordinate all these audio devices and transmit high-quality audio signals, the latest developments in connection technology are expected to promote the rapid adoption of transformative applications in the new generation of vehicle infotainment systems, and car audio buses have become indispensable.
A2B technology is specifically designed to simplify the connection challenges of emerging automotive microphones and sensor-intensive applications. It can provide high-fidelity audio and reduce the weight of audio wiring by 75%, thereby improving fuel efficiency. In addition, the A2B transceiver transmits audio, I2C control, low-speed GPIO, clock signals, and phantom power on an unshielded twisted pair cable, which can also reduce the total BOM cost of the system. In addition to making the wiring simpler, A2B, for example, the car machine can be directly connected to the microphone module through an unshielded twisted pair, and it supports a microphone array.
In the embodiment of intelligent and innovative applications, A2B technology can also be more adapted to advanced audio algorithms. Because the audio node has a fixed delay, the DSP algorithm can be used to ensure the independence of the sound zone in different positions in the car, as well as realize echo cancellation, cooperate with the microphone and power amplifier for ANC active noise reduction, and cooperate with the acceleration sensor supporting the A2B interface for RNC road noise cancellation And other functions. System-level diagnosis is also a highlight of A2B. All A2B nodes can identify a variety of fault conditions, including open circuit, reverse connection of the wiring harness, or short circuit of the wiring harness to the power supply or ground, etc. In the event of a fault such as an open circuit, a short circuit of the wiring harness, or a reverse connection of the wiring harness, the A2B node upstream of the fault can still work normally, thereby ensuring the integrity of the system. The diagnostic function also provides the ability to efficiently isolate system-level faults and facilitate subsequent maintenance.
From an implementation perspective, A2B is a serial topology with a single master device and multiple sub-nodes. The fourth-generation A2B transceiver AD243x has improved the key functional parameters on the basis of the third-generation (the number of nodes has been increased to 17, and the bus power supply has been increased to 50 W). At the same time, an additional SPI control channel (10 Mbps) has been added, which is intelligent The remote programming of A2B nodes provides efficient software over-the-air update (SOTA) capabilities. The new features of the AD243x series make it very suitable for new applications, such as microphone nodes equipped with LEDs in ultra-advanced microphone architectures.
Innovative video bus allows smart video interaction into the car cockpit
Video is a key component of the traditional car infotainment system. With the popularity of electric vehicles, the function of video Display in the car cockpit becomes more and more important. Large screens, multiple screens, and interactive screens have become a trend. On the other hand, with the development of automated driving and intelligence in automobiles, video cameras have also become a key functional component. In terms of cockpit intelligence, some manufacturers are exploring the use of cameras to observe and analyze the head, body position and eye gaze of drivers and passengers, monitor the drowsiness and distraction of people in the car, and intelligence based on face, body, and gestures. Interaction, providing facial recognition functions of each person in the car, so as to realize the functions of personalized infotainment and services, as well as carpool payment.
However, the existing SD car camera link solutions use low-bandwidth cables, such as unshielded twisted pair cables and unshielded connectors. After adopting a higher resolution camera, the bandwidth is further increased, which brings great challenges to the traditional video signal connection link. In order to solve this problem, ADI’s new car camera link technology-car camera and video bus (C2B), is a technology optimized for car camera links and can solve these problems. C2B covers three main solution definition standards:
• Reuse the existing SD standard definition unshielded twisted pair (UTP) cable and connector link to provide the simplest HD camera link upgrade.
• Use this link to transmit high-definition video with excellent picture quality.
• Use this link to meet automotive-grade EMI/EMC requirements.
C2B supports the transmission of HD resolution video through the existing SD UTP cable and connector link. Using C2B, you can easily upgrade from SD camera to HD camera without changing the existing cables and connector links. At the same time, C2B supports many other functions, including sideband control communication through the same unshielded twisted pair, thereby supporting the remote configuration of the camera module, which can further simplify the camera design. C2B also provides freeze frame detection, which is a key requirement for many OEMs. It is also an important solution that is cost-effective and versatile. C2B products include ADV7990, ADV7991, ADV7380 and ADV7381, which are currently in production.
C2B provides many benefits for car camera system connection
According to the IHS report, more than 70% of users approve of smart cockpit configuration and can increase car purchase interest, reflecting that most users currently have an increased demand for car technology and interactive experience. The technology configuration in the cockpit has become an important consideration for users when buying a car. In addition, Chinese users who rely more on smartphones have shown greater attention to cockpit technology configuration. In the future, China’s smart cockpit configuration and assembly rate will exceed the global market. The penetration rate of smart cockpits in the Chinese market is expected to increase rapidly. In 2020, smart cockpits in the Chinese market The penetration rate is 48.8%. By 2025, the penetration rate is expected to reach more than 75%, far exceeding the global penetration rate of 59.4%, showing a rapid growth trend. Behind the rapid growth of smart cockpits, it is time to make changes in the design of related systems.