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Co-operative Adaptive Cruise Control(CACC). Anirudha U. Bodhankar Roll no. 04329003, MTech04 KReSIT, IIT Bombay. Adaptive Cruise Control. Independent device. Has control over acceleration and breaking. Use sensors to detect vehicle ahead and estimates its velocity.
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Co-operative Adaptive Cruise Control(CACC) Anirudha U. Bodhankar Roll no. 04329003, MTech04 KReSIT, IIT Bombay.
Adaptive Cruise Control • Independent device. • Has control over acceleration and breaking. • Use sensors to detect vehicle ahead and estimates its velocity. • Ensures Smooth driving and less fuel consumption • Dsafe = v * T + v2 / (2r)
Adaptive Cruise Control cont… • Parameters estimated are always • not reliable • Probability of false alarm is relatively heigh
Applications of IVC/RVC • Information and warning functions • Communication-based longitudinal control • Co-operative assistance systems • Added value applications
MAC layer for IVC/RVC • Basic CSMA • RR-ALOHA • Location aware MAC
CSMA • Contention oriented • Best-effort service • Fairness is not preserved • Suffers from hidden terminal problem • wastage of bandwidth
RR-ALOHA • Decentralized MAC protocol • Transmits application as well as service information • guarantees reliable use of broadcast channel • Frame information(FI) gives status of allocation as perceived by a node. 1 2 5 3
Location aware MAC • Geographic area is divided into cells. • Trade-off for size of the cell. • Contention is used within cell. • frequency band can be reused in distant cells, depending on transmission range of nodes. • Avoids hidden terminal problem. • preserves fairness property
Network Layer of IVC/RVC • Routes the packets to desired nodes. • Classifies the nodes in five classes • Same road, same direction, ahead • Same road, same direction, behind • Same road, opposite direction, ahead • Same road, opposite direction, behind • Others • Use a location service like GPS.
Application to Blind Crossing • A sends Merge Alert(MA) to vehicles in main lane • If tOV <= tMV <= tPV MA is of relevance • Conflict resolution
Security • Use of public key private key for authentication • Vehicle its Digital Number Plate (DNP) and Kpr(DNP) • Roadside Base Station(BS) authenticates the vehicle • A Session Key (SK) which is used upto next BS.