Research On Nonlinear Dynamic Control Of Unmanned Driving Robot Vehicle Under Steering Condition

Unmanned driving robot(UDR)is a new solution for driverless vehicle.It can be installed in the driver’s cab to replace the human driver to drive the vehicle automatically in dangerous and harsh environment.In this thesis,based on the research on the structural characteristics and speed control of the UDR,the nonlinear dynamic control mechanism of the unmanned driving robot vehicle(UDRV)under the steering condition is studied.Firstly,the characteristics of each control mechanism are analyzed,and the steering manipulator model and the driving leg model are established.A nonlinear coupling dynamic model of UDRV is established by combining the dynamic model of 7-DOF vehicle,the model of driving and braking system and the ground feedback load moment model.Then,the steering control strategy model is established,which is composed of adjusting angle strategy module and adjusting angular velocity strategy module.A longitudinal control strategy model is established,which is composed of a longitudinal control pedal switching condition module and a longitudinal control pedal opening calculation module.Under the condition of steering driving,the lateral and longitudinal strategy models are integrated,and the coordinated control strategy models of “acceleration-steering” and“deceleration-steering” are established.Finally,the nonlinear coordinated control structure of the UDRV is analyzed.Then,the neural network tuning active disturbance rejection controller(ADRC)based on the disturbance observer and the self-adaptive fuzzy backstepping controller of the driving leg are established.Combined with the vehicle control strategy model,considering the nonlinear disturbance,the closed-loop system model of “UDR-vehicle-road” is established.The effectiveness of the proposed method is verified by simulation and experiment of the lateral and longitudinal coordinated control of the UDRV.The experimental results show that the proposed coordinated control strategy reasonably distributes the steering wheel rotation angle and the opening of the accelerator and brake pedal,and the lateral and longitudinal controllers proposed in this thesis improve the tracking accuracy,so that the path tracking error is kept between ±0.1m and the speed tracking error is kept between ±2km/h.