BSD+RCTA System Specification Project: RT05 2016/11/15 WNC Nancy Wu FCC Caution: Any changes or modifications not expressly approved by the party responsible for compliance could void the user’s authority to operate this equipment. This device complies with Part 15 of the FCC Rules. Operation is subject to the following two conditions: (1) This device may not cause harmful interference, and (2) this device must accept any interference received, including interference that may cause undesired operation.
HISTORY ............................................................................................................................................................... 3 1 2 SCOPE ................................................................................................................................................................ 4 3 SYSTEM DESCRIPTION .................................................................................................................................. 5 3.
1 History Version# Reviser Date 0.1 Nancy 2016.11.
2 Scope This document describes system introduce, technical requirement, function requirement, mechanism, installation, connecter interface, CAN communication and environment requirement.
3 System description 3.1 System Introduce Two 24 GHz narrow band sensors compose this system. Two major functions are included which are BSD (Blind spot detection)and RCTA (Rear cross traffic Alert). 3.2 System Diagram Master Sensor IGN GND Private CAN ECU Slave Sensor ECU is built by customer. The communication interface between 2 sensors is CAN (Private CAN or sensor CAN).
3.3.2 RCTA (Rear Cross Traffic Alert) The Rear Cross Traffic Alert (RCTA) system uses the same radar infrastructure used for detecting vehicles in the blind spot (Blind Spot Detection, BSD). Some serious accidents are happen when driver are reversing out of parking space (Refer to follow picture). The usual reason of these accidents is because drivers either fail to see a vehicle or cyclist approaching from the side or they see them too late. RCTA system provides assistance to the driver to prevent this.
4 Technical requirement 4.1 Basic parameter Operation voltage range：9~16V Typical operation voltage: 12V Operation temperature：-30℃~+85℃ Maximum power consumption ：7W Operation frequency: 24GHZ (NB) Water proof: IP67 4.2 Radar performance Frequency : 24.075 – 24.225GHz (Left side) 24.065 – 24.215GHz (Right side) FOV : 120 degree range accuracy: 0.25m range resolution:1m velocity accuracy: 0.08 m/s Velocity resolution: 0.
5 Function requirement 5.1 Detection FOV is 120 degree. 120° 120° 30m 30m 5.2 Warning 5.2.1 Blind zone define of BSD system The warning zone definition is as follow, and it can be adjusted if needed. Right side blind zone 3.8~4.5m dynamic change 0.4m 2m 7m Center of the car 0.4m 2m 7m 3.8~4.
5.2.2 Parameter of BSD system x Y Y Car Ys Xf Ys Alert Region Alert Region X Xr Extend Alert Region V Extend Alert Region Tracking Object A Tracking Object B V Unit: meter(m) Parameter Description Default value Xf Forward length of Alert region 2m Xr Backward length of Alert region 7m Ys Alert ignore area 0.4m Thold_ToS Warning hold time when target overtaking subject 0.5sec Thold_SoT Warning hold time when subject overtaking target 0.
For X: We have one linear formula as follow which is calculate from ISO 17387 Chapter 4 Table 3 T=0.1V +1.5 (where T is TTC and V is relative speed) That means different relative speed, we have different TTC.
5.2.3 RCTA zone of RCTA system The RCTA zone definition is as follow, and it can be adjusted if needed. The moving target which is with Speed between2.5m/sec~15m/sec and enter left or right RCTA ZONE and have Potential collision TTC<2.0sec The maximum subject car speed is not over 15km/hr. 7m Typ. 30m base on TTC <2.0sec Center of the car RCTA Zone Typ. 30m base on TTC<2.
5.2.4 Parameter of RCTA system X Y Car Xcf Xcf Tracking Object Tracking Object Xcr Xcr Yc Yc Position of Tracking Object will fall into the potential collision Region (length is Xcf+Xcr, Width is Yc for each side) with TTC within 2sec Parameter Description Default value Forward length of potential collision area 3m Xcf Backward length of potential collision area 5m Xcr Width of each side (right or left) 0.8m Yc 2sec TTC_RCTA Alert TTC setting 5.
6 Mechanical Requirement 6.1 Weight Weight of Signal sensor is 285g 6.2 The size of sensor 144*98*23±0.
6.3 Installation There are 4 fix locations, please refer to follow: The master sensor is installed inside the rear bumper of left, and the connecter is down.
7 Connecter interface 7.1 Connecter I/O connecter [16pin]: ACES: 50992-0161L-001 Wire connecter: Tyco 1438031-1 7.2 Pin define 8.2.1.
8.2.2.
