Management and Control of Connected and Automated Vehicle Platoon in the Process of Variable Speed Driving, Vehicle Cut-Out or Cut-In

The Connected and Automated Vehicle (CAV) platoon can run at the speed limit and the minimum safe time gap, that is, each vehicle speed is the speed limit and the time gap between adjacent vehicles is the minimum safe time gap known as constant time gap (CTG) strategy, and the platoon will reach the high traffic efficiency. This paper aims at the three situations of variable speed driving, vehicle cut-out and cut-in of the CAV platoon, proposes the methods of CAVs management and control to ensure the efficiency and stability of the CAV platoon in the process of driving using a small number of adjusting parameters. The communication delays among vehicles are considered, the simulation experiments show that the impact of the communication delay (50-200 ms) during acceleration or deceleration is very small, and then this paper adopts the communication delay of 100 ms. The control methods take the minimum safe time gap as the goal, by controlling the acceleration or deceleration of each vehicle, so that the platoon can change speed to the new speed limit within short time while keeping the minimum safe time gap all the time. When there is a presence of cut-out or cut-in movement in the platoon, the platoon can recover to the original driving state as soon as possible using corresponding three or two adjusting parameters to control the acceleration or deceleration of vehicles, and drive at the speed limit and the minimum safe time gap again. The simulation results indicate that the control methods can make the platoon reach the new speed limit or recover the original driving state from cut-out or cut-in movement quickly and smoothly, and can effectively reduce the traffic disturbance caused by cut-out or cut-in vehicle, and improve the traffic flow.