Active Disturbance Rejection Unmanned Vehicle Group Tracking Control

Transportation is an important part of industrial production and daily life.Increasing demand for transportation brings heavy burden to the existing transportation system.This will not only cause road congestion problems,but also a large hidden danger of traffic safety.The formation of unmanned vehicles can effectively alleviate the problems of road congestion and safety hazards in the transportation process.The core problem of formation driving is the synchronization of unmanned vehicles.The tracking control of the unmanned vehicle group is the specific application of the synchronization problem in practice.However,in actual driving,unmanned vehicles will be affected by complex uncertain factors that cannot be accurately modeled,such as air resistance,nonlinear friction and external interference.Errors are conductive,which will challenge the tracking control of unmanned vehicles.For the longitudinal tracking control of the unmanned vehicle group:using the pilot-follow method we establish the longitudinal tracking system of the unmanned vehicle.Then,we use an extended state observer to estimate the total disturbance that consist of the un-modeled system dynamics and the external disturbance,and then compensate the total disturbance in the feedback control to improve the control performance.The convergence and the stability of the feedback control closed-loop system are proved rigorously.Simulations are carried out to illustrate the merits of the proposed method.For the lateral and longitudinal tracking control of unmanned vehicle group:The movement of an unmanned vehicle traveling in a plane needs to be characterized by three quantities:the abscissa,the ordinate,and the deflection angle of the unmanned vehicle.Traditional method is to use the speed and angular velocity of the unmanned vehicle to control in an under-driven manner.In practice,the speed and angular velocity of the unmanned vehicle are driven by the thrust of the engine and the rotation of the axle,and the errors of unmanned vehicles are conductive,the uncertainty factors will combine with the uncertainty factors of the preceding vehicle,which will affect the lateral and longitudinal tracking control of the unmanned vehicle group.Considering the complexity of the model,this paper only discusses the external disturbance.To eliminate the negative effects of external disturbances,we developed an active disturbance rejection tracking control method.We use an extended state observer to estimate the total disturbance that consist of the un-modeled system dynamics and the external disturbance,and then compensate the total disturbance in the feedback control to improve the control performance.The convergence and the stability of the feedback control closed-loop system are proved rigorously.Simulations are carried out to illustrate the merits of the proposed method.