| With the rapid development of economy,improvement of transportation conditions,and particularly the perfection of expressway network since the 21 th century,automobile transportation is booming developing aiming at the large-scale and heavyduty.Full-Trailer Trains with its' unique advantages such as pull more and run fast,lower manufacturing costs and higher utilization rate,is accounting for considerable proportion in the road transport.While currently,the trailer train achieves movement and steering mainly depending on driving truck control.The trailer under the drag of steering mechanism,which ended up with the great offset distance,poor misalignment of rutting track,and the large width of channel in the moving process.In this paper,the control scheme of active steering for the double-bar hydraulic trailer train is proposed based on the turning theory of trailer.This project takes the core component of draught attachment as the research object,improves the motor vehicle mobility as the ultimate goal,the excellent coincidence of trailer trajectory,narrower travel channel width,and much more steering maneuverability and stability can be realized.This project has the following innovative points: First,the way between the driving truck and trailer connection.This subject breakthrough hinge and single draught attachment,putting the double-bar hydraulic draught attachment.Second,it has changed the tractor-trailer steering concept.The subject applies the intelligent control theory to achieve the trailer to the passive to the active change.The control scheme of active steering for the double-bar hydraulic trailer train is proposed based on the turning theory of trailer.The tire side deviation of double-bar hydraulic trailer can basically be ignored because of its' not high enough speed and low steering intensity,by using the Ackermann steering principle to analysis steering characteristics,the angle relationship between the tractor turns to the drive wheel steering angle and the hydraulic double rod connecting device between the tractor and the trailer is derived.A local communication system is created between the tractor and the trailer to transmit the motion data parameters of the tractor to the controller of tracker,especially the steering angle and the displacement state,which means that,the tracker using the parameters like the speed,angle of rotation,and displacement data detected in the trailer to actively adjust elongation or shortening of the double rod in the hydraulic connection device,finally achieving reproduced rut,active steering,the tractor following,and the improvement of steering characteristics about the trailer train.The virtual prototype model of the double-bar hydraulic trailer was put forward in ADAMS software,and the input and output state variables of the mechanical syst em were defined.With the control system designed in MATLAB,and the simulation for virtual prototype completed jointly in MATLAB and ADAMS,trajectory curve of tractor and trailer which viewed as particle were respectively obtained in the case where the full trailer train conducted a 90-degree and 180-degree turn around.The best consequence of control system was achieved by the commonly used adaptive fuzzy PID algorithm.Finally the simulation results show that,comparing with that ordinary train,the double-bar hydraulic trailer has better trajectory coincidence,and enhanced driving mobility.Based on the similarity principle,the scaled model of double-pole hydraulic train was designed,the hardware circuit was devised and the corresponding program were written,thus the movement state of the train could be observed intuitively.By comparing the testing results of the proportional model and simulation results in software,combing the analysis against the experimental results,the feasibility of our designed scheme for double-bar hydraulic vehicle is verified,which provides the theoretical basis for the future development and research of the automobile train. |
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