2010 automotive electronics hotspot application trend forecast
China's auto industry is likely to hit or cross the threshold of 10 million vehicles per year this year. In fact, before achieving this goal, China has become the world's second largest auto market after the United States. In current automobiles, automotive electronic systems account for an ever-increasing proportion. Many of the featured functions rely on automotive electronics technology. If we have already occupied a very important position in terms of manufacturing quantity, then specific In the automotive electronics industry, how can we synchronize with our international counterparts? In the last two years of the first decade of this century, which automotive electronics applications will become hot spots, and what challenges will they face when implementing these applications? The author selected several hot-spot applications on this issue and interviewed some related industry experts, hoping to help readers in China engaged in the design of automotive electronic systems. These hotspot applications include adaptive car headlights, LED tail lights and HID headlights, intelligent keyless entry systems, visual and radar reversing systems, etc.
AFS adds weight to ensure driving safety
The role of car lights in ensuring driving safety is obvious, and in practical applications, the traditional headlight system has many problems. For example, the existing low-beam lights have poor lighting effects at short distances; there are also problems with the dark areas of the lighting that exist when the vehicle turns and the reflected glare of the water on the ground when the vehicle is driving on a rainy day. Very good solution or improvement. The changes brought about by the Adaptive Auto Headlight (AdapTIve Front LighTIng System, AFS) system can help drivers easily face these problems.
The so-called AFS refers to a headlamp system that can automatically change more than two light patterns to adapt to changes in vehicle driving conditions. According to Steven Nelson, Freescale ’s global automotive marketing director, “At present, there are many types of AFS on the market, ranging from relatively inexpensive horizontal systems to so-called lighting“ bending â€applications. Horizontal systems adjust the verticality of the light based on the vehicle ’s load Aiming, this type of system is regulated in Europe. More advanced "bending" applications can dynamically change the light aiming or beam pattern based on vehicle load, acceleration / deceleration, steering wheel angle, weather conditions and other information. Such systems are generally made up of Stepper motor control. "For example, when driving in a curve, the light of the traditional headlights is consistent with the direction of the vehicle, so it is inevitable that there are dark areas of illumination. Once there are obstacles on the curve, it is easy to cause traffic accidents. At this time, AFS will generate light of rotating light type to give the curve sufficient illumination.
Mr. Shigeda Shinji, General Manager of the Automotive Electronics Market Center of Renesas Electronics (Shanghai) Co., Ltd., said: "There are two types of controls that can change the direction of the headlights. One type needs to actually turn the short-focus headlights, and the other type does not turn the front Lights, but rotating mirrors. But in either case, you need to increase the motor and gearbox. The input signals that determine the rotation angle are the steering angle, the vehicle speed signal, the direction lights, and the reverse switch. "Processing of the sensor signal The calculation of the headlight angle and the control of the motor are done by the MCU, sensor and motor driver. Existing automotive electronic systems can already collect information such as steering angle signals, vehicle speed, etc. and have devices such as direction lights and reverse switches, and the control of the motor is no different from other motors. Shinji Ueda also said: "The design challenge of AFS is mainly to define the specifications, and then determine how AFS works and the design of MCU software. Regarding AFS, Renesas MCU has been used in many Japanese cars for five years. Renesas can provide 16-bit MCU / M16C series and R8C series to meet the different needs of customers. "
Regarding the next development trend of AFS, Rising Tian Shenji believes that in the future AFS, some car manufacturers are considering integrating image recognition functions to detect pedestrians, vehicles and roadside obstacles. In this application, a 32-bit processor with image recognition is required. Renesas' product SH7774, which is suitable for adaptive cruise control (ACC) and lane departure warning system (LDWS), is also suitable for future AFS. LED turn signals have also been adopted in newer systems. In this type of system, there are a series of LEDs that can be manipulated to provide functions such as leveling and bending, so motor support is no longer required.
LED and HID shine in automotive lamp applications
According to Tony Armstrong, Power Products Marketing Manager of Linear Technology, light-emitting diodes (LEDs) have been used in automotive taillights for more than a decade. And Mr. Boon-Hooi Lim, Automotive LED Product Marketing Manager of Anwar High-Tech Optoelectronics Division, said: "There are already more and more cars in the entire rear combination light (RCL) (including parking lights, turn signals, tail lights and reflector lights) Etc.) Tony Armstrong also introduced: "High Intensity Discharge Lamp (High Intensity Discharge Lamp, HID) lamps include all high intensity gas discharge lamps used in general lighting, and HID used in automobiles mainly refers to HID xenon The lamp is usually used as a car headlight. "
Why use LEDs in car lights? Experts from Shiqiang Telecom said: "Compared with traditional car signal lights (such as incandescent lights), LEDs have energy saving, long life, maintenance-free, explosion-proof, easy to control and environmental protection. The advantages, combined with the independent cold light characteristics of the LED, make the shape of the lamp not deformed due to long-term heating, thereby improving the life of the entire lamp. And with the technological innovation and the rise of the market, the current luminous power and cost of LED Both bottlenecks will be resolved. "
Compared to LED taillight applications, the heat dissipation problem is still not completely resolved for headlight applications. Linear Technology's Tony Armstrong said: "The power supply of HB LED headlights really needs to pay special attention to thermal design, because they usually require 50W of power supply." Brian Blackburn, senior application engineer of ON Semiconductor, said: "Some systems A fan is used to cool the LED headlights. But this type of cooling is not a good thing for the long-term availability of LED headlights. â€Shi Qiang ’s experts said on this issue:“ Multiple LEDs are concentrated in a limited space. It will cause difficulty in heat dissipation, and the temperature of the LED module will increase, which will lead to the reduction of the life of the LED, and accelerate the light decay of the LED, affecting the efficiency and reliability of the LED driver and other components (generally the operating temperature of the component needs to be controlled below 80 ° C). The increase will also change the wavelength of the light output by the LED and change the color characteristics, which may affect automotive lighting. "He said:" To solve the heat dissipation problem, from the perspective of the manufacturer, new materials and new packaging technologies can be used. , To increase the heat dissipation area of ​​the PN junction, etc .; from the designer's point of view, there are several options to choose from, including the choice of high-quality solutions ; Heat amount control current is reduced when the temperature rises, to reduce power consumption; and selecting reasonable thermal design. "
An increasingly powerful intelligent entry system
Remote control door lock (RKE) and keyless entry control (PKE) are the most easily seen intelligent entry systems on various types of vehicles. Anti-theft is the original intention of developing these systems, and now their functions are becoming more and more abundant. For example, the car search and RES (remote start engine) functions are added to the PKE system. Mr. Zhang Jianchen, Senior Marketing Manager of NXP Semiconductors Automotive Electronics Greater China, said: "These are the functions of automotive proximity systems that are very popular in North America, and they think they should be added to the next-generation PKE system.
According to Stephen Chan, marketing manager for Microchip Automotive Products Asia Pacific: "PKE transponders are the mainstream configuration for high-end cars, and are now rapidly gaining popularity in ordinary cars. With PKE transponders, users only need to carry the transponder to open the door , There is no need to manually press the button on the transponder. "The PKE system consists of a base station and a transponder unit. The base station unit sends commands in the 125kHz frequency band, and the PKE transponder realizes long-distance command reception and response transmission through an external UHF transmitter, or uses the internal backhaul function in the same 125kHz frequency band for short-range applications. He also said: "The challenging task that PKE system design engineers need to solve is to reliably detect base station commands under any possible working conditions, while keeping all other design parameters unchanged, such as battery power usage and the physical size of the antenna. "
In order to realize the car search and RES functions on PKE, the next-generation PKE needs to expand the radio frequency link to bidirectional radio frequency communication (315 / 434MHz) with a maximum communication distance of 300 meters. With the two-way radio frequency link, the key end can obtain the feedback signal from the car end and send commands to the car at the same time. In terms of hardware, it is necessary to select a suitable MCU from 8-bit to 32-bit MCU according to different algorithms and system procedures. Microchip's PIC16F639 is a powerful, easy to program (only 35 single-byte instructions), 8-bit microcontroller based on CMOS flash memory, only need to add a transponder analog front end to make the device suitable for PKE systems. It uses Microchip's powerful PIC MCU architecture, integrated KeeLog compatible encryption module, PLVD, dual comparator and 256 bytes of EEPROM data memory in a 20-pin package.
For two-way PKE, system security, power consumption and communication distance are the three main challenges. The RES function needs to involve the engine control unit (ECU), so safety is very important. Mr. Zhang Jianchen of NXP strongly recommends using the same algorithm as the car lock system to ensure safety. Two-way radio frequency communication will result in greater power consumption, which is fundamentally different from traditional RKE technology. With traditional SAW transmitter technology, the distance is only about 30 meters. In new applications, special transceiver chips based on PLL must be selected. NXP is a leading semiconductor supplier in the engine anti-theft locking system (IMMO) and PKE market. It is a smarter entry system that can be easily upgraded from PKE based on NXP solutions. These solutions use the same algorithm, the same technology and The same ECU interface. Some key features of the NXP solution can also help designers meet the three major challenges mentioned above: 1. Integrated HITAG2 / AES128 algorithm to ensure automotive safety. 2. Realizing the battery recharging function through the low frequency link can solve the power consumption problem. 3. Committed to improving the product types of radio frequency technology, using Frac-N PLL to realize the transmitter, receiver and transceiver can ensure long-distance communication.
Hybrid visual and radar reversing system saves you from having to look back and worry about reversing
The current radar reversing system can already provide a lot of help for the driver, but it is not perfect. Due to the scattering characteristics of electromagnetic waves, if the ground has sharp protrusions or angular objects transverse to the sky, the existing system cannot effectively Perceived, so many old drivers have warned novices to look back at the actual situation when reversing. If you add a visual function to the reversing system, the driver can see the situation behind the car without turning back when reversing
Experts of OmniVision said: "The visual parking system using multiple sensors is very mature. 4 to 5 cameras are used on both EX and BMW 7 Series of Infinity, and finally 4 to 5 cameras are comprehensively output. The collected image is used to realize the visual parking function. The image looks as if it is viewed from a height. "He further stated:" The resolution of the sensor can be VGA to megapixel level. If it is VGA It may require 4 ~ 5 cameras; if it is a megapixel, 2 ~ 4 cameras are enough. And the more cost-effective CMOS image sensor will replace the expensive CCD sensor in the hybrid visual and radar system. "OmniVision can provide color high dynamic range CMOS sensors at the lowest BOM cost. Due to the extremely low sensitivity and special improvements, the company's camera can work around the clock.
However, adding similar functions is very important to grasp the cost, because it is not an indispensable function after all, and how much money consumers are willing to pay for it is also a factor that car manufacturers need to consider. Yang Ye, ADI ’s DSP and embedded processor product technology marketing manager, said: “To talk about the cost of a reversing system, you must understand the premise that during the normal driving of the vehicle, the proportion of parking time is very high Small, usually no more than 1%. So, whether it is a vision-based or radar-based system (or a combination of the two), how to use the processing power of the system in the remaining 99% of the time becomes a problem The essential."
He further stated: "Based on the above premises, a cost-optimized system must have flexibility and scalability. Flexibility means that in addition to the most basic functions of the system (reverse image, radar display and warning), it also needs to have system supply Some of the differentiated functions unique to the manufacturer, such as the system can linearly compensate for the distortion caused by the wide-angle lens (fish eye correction), can improve the image quality through automatic exposure, auto focus, automatic white balance, etc., can use the image system and The combination of the radar system determines whether it is an alarm and the level of the alarm. It can realize the vehicle's overhead synthetic image through the multi-camera method to improve the user experience. Scalability means that the system can be implemented by adding no or little cost to the car except for reversing. Other functions besides assistance, such as installing a front CMOS sensor / radar on the vehicle to realize lane departure warning, automatic cruise control, pedestrian monitoring, night vision, etc .; installing sensors inside the vehicle to achieve the occupant ’s Condition monitoring; Sensors are installed on the side to achieve blind spot monitoring. That is to say, by expanding various functions during normal driving of the vehicle and improving the user experience during parking, the system supplier can greatly increase the added value of the product without increasing Too much cost. "
How to better integrate these two different systems to provide drivers with a more accurate driving reference, avoid accidents, and reduce the loss of life and property is a great challenge for system suppliers. How to make an effective comprehensive judgment on the input of these two systems in different scenarios and give a result that is closest to the actual situation is an important standard that reflects the skill of different system suppliers. A typical example is when the noon sunlight is direct and the rear of the car is facing the dark garage door. Due to the intervention of the automatic exposure of the CMOS camera, the in-car display can clearly show the scene outside the garage, but it is impossible to see the garage. Obstacles, you need to use the detection results of the radar to detect the distance and orientation of the obstacles, judge the two results, and give the driver appropriate tips.
Based on the discussion that the system must have flexibility and scalability, the main processor in the system must have very high processing power, rich interfaces, and code-compatible cores that can meet low-cost to high-performance different requirements to ensure that the code can be Reuse. Mr. Ye Ye of ADI said: "The usual ASIC chips are difficult to meet the above requirements at the same time due to their inherent limitations, and a general-purpose processor can accomplish such tasks very well." ADI ’s Blackfin processor provides From low-end 400MHz single-core to high-performance 500MHz dual-core processors, it provides a series of code-compatible processors that meet the automotive industry standards for customers to choose for different system costs and specifications. The rich interfaces of the Blackfin family members can seamlessly connect CMOS, LCD and radar sensors. The built-in hardware acceleration unit that supports multi-layer image overlay and color gamut conversion allows customers to expand the system freely and flexibly without the need for external expansion. Extra peripheral chips. And the rich third-party network owned by ADI can provide a series of key algorithms that customers can directly use to shorten the time to market, and can also use this as a basis to expand their unique functions.
In addition to the applications mentioned above, there are some applications that are also very characteristic. For example, electric anti-pinch windows, such as heated rearview mirrors, etc., they can effectively provide convenience and improve driving safety at a lower cost for the occupants. Another example is a smart air conditioner that can be started in advance or can be set at a preset temperature, which is particularly useful for users in hot or cold areas, allowing them to enjoy a comfortable temperature as soon as they enter the car. In short, improving the comfort and safety of automobiles is the driving force for continuous innovation of automotive electronics manufacturers and designers; in the foreseeable future, the hotspots of automotive electronics will also revolve around these two themes, and whether it can be accepted at a cost acceptable to the market Turning these innovations into reality is the key to whether they can eventually become a selling point from a hot spot.
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