tailieunhanh - Intelligent Vehicle Technology And Trends Episode 1 Part 9

Tham khảo tài liệu 'intelligent vehicle technology and trends episode 1 part 9', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | 142 Longitudinal Sensing and Control Systems to benefit from several years of experience with production ACC systems to gain confidence in stepping into the active safety realm. The introduction of FCM in Japan as with all new car technology there is managed by the Japanese MLIT. In 2003 the agency issued the following technical guidance for these systems The system must alert a driver before activating deceleration by braking. System activation is limited to situations in which a driver cannot avoid a crash with deceleration. Braking deceleration must be over . The major Japanese automakers responded by introducing very similar systems as can be seen from Table . Sensing technologies employed either radar or lidar reflect the type of ACC sensing used by different OEMs. All three systems use audible alerts to initially get the driver s attention to a forward crash situation with Honda also employing impulsive braking which is in essence a tapping of the brakes sufficient to be felt by the driver. If the driver does not brake the vehicle the systems use the maximum braking force allowed by the government at the last moment to reduce the severity of the crash while at the same time pretensioning seat belts. The Honda CMBS provides a good example of how these FCM systems work. The system determines driving conditions using sensors that detect factors such as yaw rate steering angle wheel speed and brake pressure and the millimeter-wave radar detects vehicles ahead within a range of approximately 100m and a 16-degree arc. The system then calculates the distance between vehicles relative vehicle speeds and the anticipated vehicle path to determine the likelihood of a collision. Three levels of warning are employed in the Honda system Primary warning When there is a high closing rate to the vehicle ahead or if the distance between the vehicles has become dangerously short an alarm sounds and the message BRAKE appears on the information display in the .