Outline of the System for Low-Speed Collision Damage Reduction

Transcription

1 No Outline of the System for Low-Speed Collision Damage Reduction Koji Hosoda Takashi Goto Kiyonobu Takahashi Takanori Kume Hirohito Yasumatsu Ryota Mitote 37% 67% 30km/h AT SCBSAT CX-5 SCBS AT AT Summary In Japan, about 37% of the car accidents occurred in the markets was rear-end collisions, of them, 67% was occurred at 30 km/h or lower speeds. Similarly, in recent years, a number of accidents caused by false departure of AT have occurred. Focusing on this fact, Mazda newly developed a Smart City Brake Support and an "AT False Departure Restraint System", an advanced safety technology specialized in reducing the damages of collisions occurred at low speeds, which is applied to the CX-5. The Smart City Brake Support is an automatic brake system that predicts the occurrence of a rearend collision and operates the automatic brake, and the AT False Departure Restraint System which reduces the engine torque to inhibit sudden acceleration caused by misapplication between the brake pedal and the gas pedal of AT. In this paper, the general outline of Low-speed collision damage reducing system which is Mazda s first time production is reported. Zoom-Zoom SCBSAT CX-5 Fig.1 37% (1) 67% 30km/h Fig.2 (2) AT 16 Vehicle System Development Dept. 156

2 No ,000 (3) (3) 17 (3) Others 5 Single vehicle crash 7% Pedestrian-car collisions 9% Turning collisions 15% Rear-end collisions 37% (1) SCBS 4km/h30km/h STEP 1 STEP 2 Fig.3SCBS SCBS Crossing collisions 27% Fig.1 Types of Traffic Accident (1) STEP 1Electronic Brake Prefill Percentage 35% 30% 25% 20% 15% 10% 5% 0% 100% 90% Percentage 80% Cumulative Percentage 70% 60% 50% 40% 30% 20% 10% 0% Vehicle Speed Km/H Fig.2 Distribution of Vehicle Speed in the Rear-end Collisions (2) CX-5 Zoom-Zoom Cumulative Percentage STEP 2Automatic Emergency Brake Fig.3 Functional Overview (SCBS) (2) AT 10km/h Fig.4 w/ function w/o function Erroneous pedal operation (Full throttle caused by pedal misapplication) SCBSAT AT Warning and reduce eingine torque Peel out Fig.4 Functional Overview (AT False Departure Restraint System) 157

3 No SCBSAT DSC PCM BCM ECU CANler Area Network Fig.5,6 SCBS DSC PCM Laser Sensor Meter DSC PCM Fig.5 Parts Layout PCM METER Fig.7 Sensor Mount Vehicle Speed Steering Angle Throttle Position Laser Sensor Calculate a Target of Acceleration Warning Sound Windshield Calculate a Target Deceleration Warning Display Object Obstacle Detection DSC Brake BCM Brake Lamp Fig.6 System Configuration Fig.8 Sensor Appearance (1) (2) DSC Fig.78 3 BCM SCBS SCBS DSC (3) PCM SCBS AT 158

4 No DSC PCM SCBSAT (4) BCM DSC (5) SCBS AT Fig.9AT Multi Information Display 9.8m/s 2 μ= km/h 15km/h30km/hSCBS 50% 25%Fig.10 1m Fig.11 15km/h () 4m 1 3m cm Collision Speed [km/h] w/o SCBS w/ SCBS (a) SCBS Fig.9 Multi Information Display (b) AT False Departure Restraint System Rerative Speed with Leading Vehicle [km/h] Fig.10 Collision Speed with or without SCBS Eng.Brake Request SCBS (1) 6m Brake Assist Request Brake Prefill Request SCBS 4 Deceleration Request Distance 0.5 m (2) Vehicle Speed 0 km/h 500ms 1.0 Time (3) Fig.11 Effect of SCBS 159

5 No AT (1) SCBS SCBS 4m SCBS (2) AT a. b. (3) 50% 25% Fig.12 SCBSAT (1) () (2) (3) () No.86pp Collision Speed [km/h] w/o AT False Departure Restraint System w/ AT False Departure Restraint Systsm Distance to Object [m] Fig.12 Collision Speed with or without False Departure Restraint System 160