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Team Pishro-Nik and Ni Chris Comack - Simon Tang - Joseph Tochka - Madison Wang. Car-to-Car Communication for Accident Avoidance. 02.12.08. Professor Pishro-Nik Advisor, Assistant Professor, ECE . Professor Ni Advisor, Assistant Professor, CEE. Background.
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Team Pishro-Nik and Ni Chris Comack - Simon Tang - Joseph Tochka - Madison Wang Car-to-Car Communicationfor Accident Avoidance 02.12.08 Professor Pishro-Nik Advisor, Assistant Professor, ECE Professor Ni Advisor, Assistant Professor, CEE
Background • Automobile accidents are both dangerous and costly • Over 42,000 fatalities in the United States in 2005. • More than 2.9 Million injuries from 6.4 Million car accidents annually. • Combined cost of 230+ Billion dollars per year. • Responsible for 5% of preventable deaths each year (JAMA). • Goal: To provide a system to reduce these rates by warning drivers before a collision happens. How? • Use GPS to track position and OBD-II to monitor speed and acceleration of vehicles. • Communicate this information among cars on the road via Dedicated Short Range Communication in the 5.9GHz spectrum. • Government has allocated this spectrum specifically for Intelligent Transportation Systems – the responsibility is now on engineers to implement it! Source: Mokdad AH, Marks JS, et al. (March 2004). "Actual causes of death in the United States, 2000". JAMA291 (10): 1238–45.
Overview of System and Goals • PDR schedule anticipated having each separate module working and interfacing with a single microcontroller unit by midway point. • Goals partially met: • Design, prototyping and coding completed in part for each module. • Circuits for OBD-II interface and Ethernet controller built – still need full implementation of code. • Code for GPS and microcontroller partially completed. • To be completed: testing and analysis of data, integration of system components with MCU, coding of collision detection algorithm and network protocol.
Proposed Solution Use of Car to Car Communication • Cars 2 & 3 emit audio warning indicating Car 1 is decelerating rapidly. • The cars operators have more time to respond to dangerous situation, decreasing risk of collision.
Design & Requirements Utilize OBD-II to find speed, acceleration, pedal position, and other information from cars computer Standard on cars made after 1996 – more than 60% of the ~250 Million registered cars on the road in the US. Use GPS to find location of vehicle DSRC (Dedicated Short Range Communication) Transceiver for communication between vehicles System must be scalable and expandable
Transceiver Specifications • Denso DSRC Wireless Transceiver • 802.11p compliant ~5.9 GHz • Ethernet communication • Testing currently in progress
Transceiver Test Results • Logic Analyzer test with 32 byte test packet
Transceiver – Things to Come • Confirm Range (at least 150 m) • DENSO claims 280 m @ 250 kbps • Confirm receiving functionality • Implement ability to receive and send from multiple sources • Use of Medium Access Control • CSMA/CA (Carrier Sense with Multiple Access Collision Avoidance) – IN PROGRESS
Packet Components • Time Sent • ID# • Sender ID# • Position • Velocity • Acceleration
CSMA/CA Protocol • Carrier Sense Multiple Access with Collision Avoidance (MAC) • Reduces the chance of collisions because the channel is sensed before transmission. • Hidden Terminal Problem • Possible Solutions: increase power to nodes, use omni-directional antennas, remove obstacles, move the node, use protocol enhancement software, using space diversity • RTS/CTS
Global Positioning System • Serial Transmit/Receive • Transmit at 4800 baud - Coded • Receive at 4800 baud - Coded • Communication Protocol • Communication interface – In Progress / partially coded • Get position • Test Cases • Validate responses • Compare Latitude and Longitude
Global Positioning System • Metallic object may greatly reduce the accuracy of the GPS because of reflection of signals • There are atmospheric conditions that increase error in GPS • The system accuracy will not be greatly effected because the other GPS will be experiencing the same conditions
General Information • The unit will only keep information about other vehicles for a limited time. After this duration, the information about this vehicle will be cleared. The unit will only keep the most updated information on any vehicles • There will be different audio warnings
OBD-II Implementation • On Board Diagnostic – standard protocol • Proprietary standards from different manufacterers • Government mandates certain information must be provided, including: • Speed, acceleration, pedal position
Deliverables • Working communication between multiple cars • Each unit integrates correctly between GPS, OBD-II, integrated transceiver, and microcontroller • Demonstration of real world functionality