Research On The Maximum Service Braking Supervision Algorithm For Middle And Low Speed Maglev Train

With the rapid development of country’s rail transportation,maglev trains,as a new type of efficient and clean transportation tool and a supplement to the wheel-rail transportation network,are taken seriously.There is a demand for the maximum service brake to replace the emergency brake in operation,that is,the maximum service brake is used by controlling the maglev for the first time,and the emergency brake is used as backup.Because the maximum service brake cannot meet the safety requirements of SIL4(Safety Integrity Level 4),the maximum service brake needs to be supervised.The main works includes:(1)Analyze the motion state of the maglev train and the Force under each motion state,the traction,braking force and resistance of the train.Then refer to IEEE1747.1 to establish a train safety braking model.(2)According to the different motion states of the train when the maximum service brake is triggered,analyze the motion process of trigger braking in the traction state,the coast state,and the braking state.Then calculate the target stop point and emergency brake trigger point position after the brake is triggered by the train traction calculation formula and the principle of conservation of energy.Use the principle of conservation of energy to determine whether the train needs to trigger emergency brake in each cycle or not.(3)By analyzing the possible conditions of the ramp,design an algorithm to deal with the ramp during the operation to ensure the ramp in the process of calculating the parking point is closer to the real ramp.(4)Protection is provided in the event of a power loss failure,and it proves that the braking distance is the longest when the train loses two sets of power at the same time during the braking process.Set up cases to verify if the results meet expectations in different situations.(5)Simulation and analysis of the obtained data prove if the algorithm meets expectations at different speeds,different motion states,and different traction braking levels.According to several aspects of research,it concludes that the maximum service brake supervision after the maximum service is triggered in different scenarios can protect the train’s safety.It can also output emergency braking commands to increase the braking level when the supervision is abnormal,so as to achieve the goal of supervising the maximum service braking and ensuring driving safety.The results provide a useful reference for the research of medium and low speed magnetic levitation.