Research On Dynamic Performance Of Light Maglev Vehicle Running On Tight Curves

As a new type of rail transit,medium and low-speed maglev transportation has the characteristics of green environmental protection,good riding comfort,small turning radius and strong climbing ability.Therefore,it has been preferred by many cities.Recently,there are two opened commercial lines which are Changsha maglev line and Beijing line S1.In addition,two maglev tourism lines,Qingyuan and Fenghuang,are under construction and have good development prospects.The Changsha maglev Line and Beijing S1 Line,which have been put into operation,have a one-way traffic volume of about 25,000 to 30,000 people in one direction during peak hours.In order to expand the application range of medium and low speed maglev,light maglev with low capacity and smaller gauge has begun to attract attention.Curving performance is an important performance index to evaluate medium and low speed maglev vehicles.It is closely related to lines and station design.Additionally,its quality directly affects the running safety and running quality of vehicles.Therefore,curving performance was studied to ensure the lateral safety of vehicles and the passenger ride comfort,so that vehicles have a good dynamic passing performance.In the engineering background of light maglev vehicle,the technical features of the vehicle were introduced.According to project target,circuit parameters were designed.The structural kinematics decoupling ability of levitation frames were studied by D-H transformation.The state that the coupler should make the car body satisfy was analyzed,and the interference verification was carried out on the position of the adjacent car body connected by the coupler.Moreover,the dynamic of the vehicle was studied by using a dynamic model with active control.The specific work carried out and the relevant main conclusions were obtained as follows:(1)According to the technical conditions of the vehicle,the curve line parameters were designed,which affect the running stability of the vehicle,the comfort of passengers,and the engineering cost.The superelevation setting of the light maglev line is related to the track gauge,the height of the center of gravity of the vehicle and the cross wind.After comprehensive consideration,it is recommended that the maximum cross slope angle of the line should not exceed 6° in general and 8° in difficult cases.The minimum radius of the curve line that the vehicle can pass through is mainly restricted by both the mechanical structure and the comfort of passengers.When the superelevation is not considered,the minimum curve radius that the vehicle can pass is 50 m.(2)Taking the left and right modules of the levitation frames as two independent overall structures,the structure kinematics decoupling analysis of levitation frames were carried out,and the D-H transformation was used to analyze the condition that levitation frames meet the structure decoupling,and the design parameters of rotatory joint bearing and elastic element of suspension lug were obtained,so that the levitation frames have the ability of kinematics decoupling in structure to meet various kinematic requirements for curve passing.(3)The state of vehicle on the curve was analyzed,the state that the coupler should satisfy the car body was calculated from horizontal and vertical angles respectively,and the motion interference between the adjacent vehicle bodies connected with coupler was analyzed from the angle of geometric.(4)The layout of the anti-rolling device was optimized in dynamics.The results show that the larger distance between the anti-rolling sheet beams,the better stress state of the boom.Meantime,the vertical force can be smaller,and the shaking motion of the module can also be restricted.The influence of the distance between the booms on the boom force is inversely proportional within a certain range.According to the simulation results,the layout of the anti-rolling device was optimized that the distance between anti-rolling beams is increased from 580 mm to 1600 mm,and the distance between booms is increased from640 mm to 700 mm.(5)The dynamic response of the vehicle was analyzed when it passes the 50 m radius curve under different working conditions.The results show that the vehicle has the ability to pass through the 50 m radius curve.It is recommended that when the cross slope angle is2.4°,the curve passing speed limit is 18～25 km/h.When there is windy weather,the maximum wind force that allows the vehicle to safely pass through the 50 m curve cannot exceed level 7.