Research On Control And Communication For Quadrotor UAV In Traffic Control System

The rapid development of our country road traffic network and the characteristics of large-scale vehicle travel time and space make it more difficult to collect traffic information with fixed detector, boosting the research interest on air detector and its application in traffic control system. In this paper, we will investigate the trajectory control and communication issues of a quadrotor which serves in traffic information collection. The main research content is as follows:To begin with, the background of traffic control system, the currently used traffic information acquisition methods, the role of quadrotor unmanned aerial vehicle in collecting traffic information are introduced. An overview of the research on quadrotor trajectory tracking control and communications system is summarized. Besides, the source and the importance of this paper's thesis are also described.Afterwards, the dynamic model of the quadrotor UAV is presented with the external disturbance lump being modelled as exogenous liner system. A nonlinear observer is then separately designed to estimate and compensate for the disturbance lump online. A backstepping trajectory controller is presented with the estimate of external disturbance. To handle the actuator's loss of effectiveness fault, an additional term is added to make the presented controller fault-tolerant.Furthermore, based on the insensibility of sliding mode control(SMC) method to model uncertainty and external disturbance, a hierarchical backstepping sliding mode fault tolerant control scheme is put forward for the quadrotor UAV. Sliding manifolds and virtual controls for outer loop and desired attitudes for inner loop are subsequently determined from which the ultimate backstepping sliding mode control law is obtained.At last, we consider the communication system between ground station and the UAV and give the top-level architecture design for the framework. Function division of each main part and their collaborations is stipulated, communication protocol is made, classification, encoding, encapsulation, error checking and format of communication data are also specified. In addition, the key implementation of serial communication between computer and wireless transmitting equipment is also provided.