Design And Research Of Active Controller Of Pantograph For Monorail Train

Urban rail transit has become an indispensable mode of transportation for people because of its convenience and speed.The straddle monorail is a type of urban rail transit,which is different from other types of rail transit.Due to its unique load-bearing and pantograph-catenary coupling method,the straddle monorail has the advantages of strong climbing ability and small turning radius.Especially suitable for special landforms such as mountain city.With the continuous development of electrification and intelligence of rail transit in recent years,the stability and reliability requirements for the operation of monorail are continuously improved,and the pantograph-catenary relation is one of the keys to ensure the stable operation of vehicles.The contact pressure of the pantographcatenary is an important factor in evaluating the quality of pantograph-catenary relation.Excessive contact force is likely to cause wear on the pantograph’s head,distortion,cracking and even breaking of pantograph,if the contact force is too small,The pantograph will leave the surface of the catenary and cause arcing to burn the pantograph’s head.The resulting strong electromagnetic interference will affect the normal operation of the train’s electrical equipment.The instantaneous inrush current may even damage the electrical equipment,which will not only cause huge economic losses may also affect the safety of passengers.In response to this problem,this paper proposes an active control method of straddle monorail’s pantograph-catenary system to reduce the contact force fluctuation of the pantograph and improve the quality of the current.The research content includes the following aspects:(1)In this paper,the monorail’s pantograph is used as the control object.According to the structural characteristics of the monorail’s pantograph,a two-dimensional calculation model is established,its static characteristics are analyzed,and then the monorail’s catenary is equivalent to a fixed stiffness model and established The nonlinear dynamic mathematical model of the straddle monorail’s pantograph-catenary coupling system is simplified and linearized for the convenience of calculation and solution,and the corresponding Simulink dynamic model is established,combining the monorail traffic operation and the pantograph-catenary relationship standard The characteristics of the contact force response and frequency response of the pantograph at different speeds are analyzed.The results show that without active control,the contact force fluctuates greatly and does not meet the standard of the monorail pantograph relationship,and the faster the speed,the greater the fluctuation,The more violent the vibration.(2)The brushless DC motor has a key role as the actuator of the active control system.Firstly,the selection basis of the actuator is analyzed.According to the dynamic characteristics of the pantograph,the dynamic parameters of the brushless DC motor are calculated to match the parameters,and Design the corresponding mechanical drive structure,and then determine the drive control method of the brushless DC motor according to the parameter properties of the brushless DC motor,and establish the double closed-loop control Simulink model of the brushless DC motor,and analyze the motor under the double closed-loop control effect.The response characteristics under load and load disturbance show that the double closed-loop control of the brushless DC motor can meet the regulation requirements of the maximum vibration main frequency of the singletrack pantograph in response speed and anti-load disturbance capability.(3)On the basis of the above,the fractional order PID and neural network PID controller models were established respectively to complete the construction of the entire active control system.By comparing and analyzing the contact force response indicators of the two control algorithms,the neural network PID can more effectively reduce the contact force fluctuations,With stronger robustness,neural network PID has lower overshoot and shorter time to reach steady state in terms of adjustment characteristics.(4)According to the active control method,the hardware platform required for the experiment was built,including pressure signal acquisition and conditioning circuit,display circuit,data storage circuit,and main control circuit and motor drive circuit.According to the hardware characteristics and control method,the corresponding software was built platform.Considering that there are many difficulties in the direct measurement of the contact force of the bow net,the indirect measurement method of the contact pressure of the pantograph-catenary is designed: the contact force is indirectly measured by measuring the tensile force of the spring and calibrating the contact force.Finally,the active control experiment of the monorail pantograph is simulated.The results prove that the designed monorail pantograph active control system can effectively suppress the fluctuation of the contact force of the pantograph and improve the relationship between the pantograph and catenary.