Optimization Of Air Suspension Parameters Of Single-axle Monorail Bogie

The straddle monorail is the key technical equipment for the straddle monorail system.There are two types of straddle monorail vehicles,one is a two-axle bogie monorail vehicle with air suspension adopted by Chongqing Rail Transit Line 2 and Line 3.Due to the air suspension of the vehicle,the ride comfort is significantly improved.In addition,the bogie is lightweight and easy to maintain.The other is a single-axle bogie monorail vehicle with an hourglass spring developed by Bombardier,that is inferior to the two-axle bogie with air suspension in terms of the ride comfort.At present,domestic research on single-axle bogies with air suspension is rare.Therefore,the structural scheme of the single-axle monorail bogie based on air suspension is designed,the dynamics performance is analyzed and dynamic parameters of the vehicle are optimized.The main research work and achievements are as follows:(1)Compare the existing characteristics of the two-axle monorail bogie and the single-axis monorail bogie,the structural scheme of the single-axle monorail bogie based on air suspension is proposed and its traveling mechanism is analyzed.(2)After simplifying the components and structure of the complex vehicle system,the single-axle monorail vehicle topology and a multi-body dynamics model for monorail vehicles are established.(3)The dynamic performance index of single-bogie monorail vehicle with air suspension is analyzed by simulating the established dynamic model,which includes curve passing,running stability and comfort,etc.The analysis results show that the riding comfort index of single-axle monorail vehicles with air suspension running at different speeds is less than 2.5,indicating that the riding comfort of single-axle monorail vehicles with air suspension is better than that of single-axis monorails with hourglass springs.(3)In order to optimize the matching suspension parameters,the monorail vehicle is further improved in driving stability while maintaining its riding comfort.Using the sensitivity analysis method,the air suspension parameters that have a significant influence on the stability of the single-axis monorail vehicle are selected.(4)The suspension parameters of monorail vehicle as the design variables which influences significantly is optimized for driving stability of the monorail vehicle and the matching suspension parameters are obtained.The optimization results show that the vehicle pitch angle is reduced by 9.7% and the vehicle body yaw angle is reduced by 3.4%,indicating that the driving stability of the single-axis monorail vehicle can be improved.