Perception-control Integrated Designing Method For Tractor-trailer Vehicles

Tractor-trailer vehicle composed of tractor and trailer is a modular vehicle system,which has been widely applied in various fields,such as logistics transportation,disaster investigation and rescue.However,limited by the mechanical structure characteristics,tractor-trailer vehicle will suffer from unmeasurable states,state constraints,underactuated dynamics and friction uncertainty.Therefore,this paper is dedicated to put forward a set of perception-control integrated theory,in order to enhance the adaptability and maneuverability of the system.Firstly,for the purpose of accurate perception and control,we choose the system independent coordinates wisely.Next,based on the Lagrange equation,the dynamic model of system has been constructed.Besides,we clarify the nonholonomic constraints and assumptions about its working conditions.Furthermore,theorems of robot system are employed to verify the rationality of its mathematical model.Secondly,in term of the technical difficulties in kinematics and dynamics,a coordinated trajectory tracking control for tractor–trailer vehicles via constrained model predictive control and direct adaptive fuzzy techniques is proposed.Constrained MPC is adopted to deal with the trajectory tracking and underactuated problem.Meanwhile,direct adaptive fuzzy technique is employed to track the desired velocity,which enhanced the robustness and adaptability of the system.Thirdly,in the absence of disturbance and velocity signals,an ESO-based perception-control integrated control strategy is introduced to deal with the related issues.In the dynamics level,robust terminal sliding model control is introduced to achieve the tracking control for velocity signals.At the same time,extended state observer is developed to observe the velocity signals in perception level,which not only solves the technical difficulties about absence of velocity signals,but also lays the theoretical basis of perception level during the coordinated control process.Lastly,the friction effect,the relevant perception and control methods for tractor-trailer vehicles are summarized.At first,on the basis of the previous research about friction,a parametric friction model for tractor-trailer vehicle is constructed.Furthermore,from the view of perception and control,RBFNN-based and SMC-based friction identification and compensation mechanism is proposed to deal with parametric friction.The effective combination of the aforementioned mechanism enhanced the robustness and adaptability for friction.Not only the stability proof of tractor-trailer vehicle system is demonstrated,but also the feasibility and effectiveness of the perception-control integrated strategy are verified by the simulation in Matlab/Simulink environment.The research results of this paper show obvious advantages in improving the operability for the system,which motives us to make further theoretical research and engineering exploration.