汽车主动安全新技术

The Technology Behind Active Safety Systems in Cars March 26 2016 by Editorial Team Want to know about the components used in active safety systems Today s cars are becoming smarter and safer with the help of advanced technology and data processing New systems are arriving every year to assist drivers from automatic high beam control to pre collision braking systems becoming the norm in practically all kinds of cars The Technology There are three major forms of sensors used to assist drivers in cars LIDAR radar and cameras Each of these sensors can be beneficial in different ways and are often combined to achieve better solutions LIDAR LIDAR Light Detection And Ranging is a technology that relies on lasers in order to measure distance In automotive applications these systems implement infrared 904nm lasers that fire hundreds of pulses per second LIDAR sensors are used by numerous companies such as Toyota s Dynamic Laser Cruise Control system Volvo s Front Collision Mitigation Support system and Infinity s Intelligent Cruise Control system These LIDAR sensors are often paired with other technologies such as cameras or radar to provide additional data An example of this sensor fusion is Continental s Multi Function Camera with LIDAR MFL system that was developed for Toyota This module s dual sensors are able to provide a pre collision system lane departure alert and automatic high beam control Continental Corporation s Multi Function Camera with LIDAR Radar Radar is one of the predominant sensor technologies used in advanced driver safety systems These systems measure the time of flight frequency shift and the amplitude of the return signal to determine what information is relevant Radar systems are used in automotive applications in systems from blind spot monitoring to forward collision warning Just like the LIDAR sensors radar sensors are often combined with other technologies such as cameras to obtain better data Delphi Automotive makes a module called the Radar and Camera System RACam that integrates both a radar sensor and camera into a single module By using these two sensors the RACam can provide a lot of functionality According to Delphi the dual sensor system can achieve full speed adaptive cruise control lane departure warning lane keeping headway alert forward collision warning pre crash collision mitigation full autonomous braking pedestrian detection object detection headlight control and traffic sign recognition All of this technology is integrated into a package that s mounted inside the car in front of the rearview mirror Delphi s Integrated Radar and Camera System Cameras Cameras play a huge role in many driver assistance systems Many systems use cameras and computer vision algorithms to augment other systems as mentioned above and to stand on their own By using FPGA s and powerful processors sophisticated image processing can be done in real time to obtain valuable data Some current vehicles are packed full of cameras that can provide many different forms of data The diagram below shows what types of data can be obtained from cameras mounted in various locations XILINX s Driver Assistance System In addition to monitoring the roadway cameras are also used in vehicles to ensure that the driver is paying attention One such system is DENSO s Driver Status Monitor This system detects a driver s face angle long duration eye closure drowsiness level and head position by using a camera and IR LEDs for nighttime illumination The computer in the system uses image recognition and processing technologies to detect the driver may be distracted or drowsy The system is then able to produce a warning or adjust the direction of the side mirrors overall safety comfort and convenience DENSO DYNAMICS Driver Status Monitor Thermal Camera Thermal cameras aren t a very popular option for driver assistance systems due to their cost These systems are usually found in luxury vehicle brands such as BMW Audi and Mercedes These thermal cameras use image processing to identify pedestrians and animals and alert the driver even if lighting is not ideal Mercedes Night View Assist FLIR manufactures the PathFindIR II system that incorporated a rugged camera and image processing into one system The pathfinder system has a range that far exceeds traditional high beam lights and can alert the driver if it detects a person or animal FLIR gears this system towards trucking and first responder applications FLIR s PathFindIR II The Future Ten years ago many of these systems would have been considered science fiction Five years ago many these safety systems were reserved for luxury vehicles Today these systems can be found in many inexpensive cars These driver assistance systems are becoming