Planning and Simulation for Autonomous Vehicles in Urban Traffic Scenarios

Download or read book Planning and Simulation for Autonomous Vehicles in Urban Traffic Scenarios written by Xinchen Li (Ph. D. in electrical engineering) and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Traffic accidents result in a high number of fatalities each year. This brings up the importance of developing Autonomous Vehicles (AV) and Advanced Driver Assistance Systems (ADAS), due to their potential of increasing traffic safety by reducing vehicle crashes caused by driver errors. It could also be helpful to deploy the intelligent transportation systems (ITS) in different traffic scenarios to increase the efficiency of traffic flow and enlarge the traffic capacity. Planning and control of the autonomous vehicles, the two essential modules in autonomous driving, are still facing severe challenges in adapting to various traffic scenarios and complex environments. The planning and decision making of vehicles in urban traffic environment are still a big challenge for autonomous vehicles due to its complexity and uncertainties. Hence it is necessary to develop decision making and planning algorithms for vehicles in urban traffic, especially in intersections. Also, velocity profile planning for autonomous vehicles is also required based on various requirements according to the environment. Additionally, a convenient method for testing and validating the developed algorithms is also required. Hence a good simulation environment is important in the field of autonomous vehicles. This dissertation contributes to planning and decision making of autonomous vehicles in urban traffic scenarios as well as developing a way of generating realistic simulation environments as test beds to validate developed autonomous driving algorithms. Decision making methods and planning methods for autonomous shuttles and autonomous vehicles in urban traffic are proposed. A rule based decision maker working for last mile problem is introduced for an autonomous shuttle so that the autonomous shuttle can deal with typical traffic on designated routes. Then to deal with complex and uncertain urban traffic scenarios when the ego autonomous vehicles doesn’t have full observability over other vehicles’ states, a Partially Observable Markov Decision Making Process (POMDP) based decision making algorithm is proposed for solving the roundabout intersection planning problem with multiple vehicles involved. Moreover, a velocity planning method for autonomous shuttle in geo-fenced area is developed, such that passengers in the autonomous shuttle are safe and comfortable. In order to improve the performance of decision making algorithms, vehicle behavior and trajectory prediction methods are also studied. Sensor perception is an important part of the autonomous driving as the ego autonomous vehicle is detecting the environment and surrounding vehicles all the time. Noise is inevitable during the perception and some internal states of other vehicles are not detected. Hence, a Kalman filter based vehicle trajectory tracking is introduced to take care the measurement noise in the perception as well as to estimate the vehicle internal states. A change point detection based policy prediction method is also introduced for determining the most likely vehicle behavior given a series of observation data along the vehicle trajectory. Combining both methods, a vehicle trajectory prediction over a future period of time is also proposed. In addition, a method for developing simulation environment using real map data and 3D rendering based on a game engine is presented as a powerful tool for developing simulations for intelligent transportation systems. All the proposed methods are provided with simulation and test results to demonstrate the efficiency.