Straddle-type Monorail Vehicle Research Articles

Lateral Dynamic Performance of High-Temperature Superconducting Pinning Maglev Vehicle Driven by Electrodynamic Wheel at Medium and Low Speed

High-temperature superconducting (HTS) pinning maglev has the advantages of self-stationarity, low noise and resistance. This technology can be applied in urban rail transit, such as straddle-type monorail vehicles. Due to the limited space for placing the drive device above the track, electrodynamic wheel (EDW) drive can be applied effectively utilizing the ample space on both sides of the track, realizing contactless drive. In this paper, the lateral dynamic performance of an HTS pinning maglev vehicle driven by EDW is analyzed. Initially, 2-D transient simulations under various rotational speeds of the EDW are conducted. The influence of different working air gaps on the device's normal force and propulsion force is analyzed. Subsequently, a dynamic model of HTS pinning maglev vehicle with EDW is established. EDW's influence on the lateral dynamic performance of HTS pinning maglev vehicle is analyzed, and the lateral dynamic performance of the vehicle at various speeds is simulated. The results show that the HTS pinning maglev vehicle driven by EDW has good lateral dynamic performance in the low and medium speed range, and EDW can effectively improve the lateral stationarity of HTS pinning maglev vehicle. This study can provide a new driving mode for HTS pinning maglev vehicle and reference for improving and optimizing the existing medium and low speed straddle-type monorail vehicles with HTS maglev technology.

Shimmy analysis of straddle-type monorail vehicle with single-axle bogies based on factor model

Shimmy is one of the important factors affecting the ride comfort and lateral stability of straddle-type monorail vehicles with single-axle bogies (SMVS). To obtain the main parameters affecting SMVS shimmy, a global sensitivity analysis strategy for SMVS shimmy is proposed. The shimmy response surface model is constructed, and the sensitivity analysis of the shimmy response surface model is carried out by the Sobol method. Based on this, the shimmy factor model of SMVS is established by factor analysis method. A novel SMVS shimmy analysis method based on factor model is proposed. The shimmy factor model is verified by the dynamic model of SMVS. The results show that 11 main factors affecting the shimmy are obtained by sensitivity analysis. Through the dimension reduction technology of factor analysis, four main factors affecting SMVS shimmy are extracted. The complex coupling relationship between the shimmy factors of SMVS is revealed. The established shimmy factor model can effectively analyse the shimmy state of SMVS, and the dynamic simulation results also show consistency. This study not only proposes a new perspective to understand the SMVS shimmy mechanism, but also provides the foundation for further optimal design of monorail vehicle stability.

Sensitivity-based, space rod system multi-objective design of straddle-type monorail vehicle with single-axle bogies

In order to study the influence of the space linkage system on the stability of the straddle-type monorail vehicle with single-axle bogies, the sensitivity analysis of the space linkage system is identified based on the Pearson coefficient method to determine the importance of each component of the single-axle bogies. The dynamics model of straddle-type monorail vehicle with single-axle bogies is established by the multi-rigid body dynamics. The Pearson analysis method is used to identify the key parameters of the space linkage system. Based on that, dynamic response optimization model of space bar system is developed to carry out a multi-objective suspension design optimization process. The results show that the maximum sensitivity parameter for the RMS value of yaw acceleration and pitch angle acceleration is the length of the longitudinal tow bar; there is a correlation of approximately 0.088 between the stiffness K and the damping coefficient C of the hydraulic shock absorber. After optimization the root mean square of lateral acceleration of the optimized single-axle bogie vehicle is reduced by 6.0%.

Operational safety assessment of straddle-type monorail vehicle system based on cloud model and improved CRITIC method

This paper proposes an improved critic method and establishes an operational safety assessment method for straddle-type monorail vehicle system based on cloud model and improved critic method. Firstly, according to the structure and function of straddle- type monorail vehicle system, the reliability index system of straddle-type monorail vehicle is established, and the weight value of reliability evaluation index is determined by improved critic method. Then, the cloud model expression of reliability evaluation index of straddle-type monorail vehicle system is obtained by virtual cloud. finally, similarity analysis is conducted between the new cloud of straddle-type monorail vehicle system reliability comprehensive index and the cloud model of reliability evaluation set, so as to judge that the comprehensive cloud model of straddle-type monorail vehicle system can be used to evaluate the operation status of “main functions” of the system. The analysis shows that the reliability evaluation method of straddle-type monorail vehicle system based on cloud model and improved critic method can correctly describe the daily operation of straddle-type monorail vehicle system in Chongqing, which provides a method reference for reliability evaluation of straddle-type monorail vehicle system.

Semi-active lateral control simulation of straddle-type monorail dynamic model with single-axle bogies

Lateral stability of straddle-type monorail vehicle (STMV) with single-axle bogies, as a new type of bogies, has been paid more and more attention. To solve it the lateral control method of a semi-active suspension system for STMV dynamic model with single-axle bogies based on magnetorheological fluid damper is proposed. The full-scale dynamics model of 34 freedom and magneto-rheological (MR) damper is established. An adaptive fuzzy hybrid strategy for STMV dynamic model based on vehicle body acceleration and velocity feedback is designed. The inverse mechanical model of MR damper is established to predict the control current. The dynamic characteristics of a semi-active suspension system based on MR damper model are studied by numerical method. The dynamic response of a STMV model with a semi-active suspension system is analysed. The simulation results show that the proposed adaptive control strategy can improve the comfort of the vehicle and improve the stability of the operation.

Optimization research on arc height of running surface based on reducing partial wear of straddle-type monorail vehicle running wheel tire

This article proposes an ideal of reducing the partial wear of the running wheels by optimizing the arc height of the running surface to improve the wheel-rail contact state. To realize this idea, two kinds of concave and convex running surfaces were designed, the “running wheel-rail beam” finite element model of three kinds of rail surfaces of concave, convex, and plane were established. Taking the arc height of the running surface as the design variable, the total friction work and the friction work deviation (FWD) value as the dual optimization goal, an optimization model of arc height of running surface was established based on finite element model and multidisciplinary optimization platform Modefrontier. An improved genetic algorithm was used and an co-simulation optimization mode was put forward in the optimization. The optimization results show that when the concave height of the inner running surface is 22.62 mm, the total friction work and the FWD values are reduced by 11% and 11.8% respectively; When the convex height of the outer running surface is 11.81 mm, the objection values are reduced by 4.9% and 32.1% respectively. An ideal running surface was obtained and the life of the running wheel was extended by the research.

Improving ride comfort of straddle-type monorail vehicle with single-axle bogie by active suspension

This article is concerned with improving the ride comfort of straddle-type monorail vehicles with single-axle bogies by using electro-hydraulic actuator active suspension, which is a new research field. Based on the 15-DOF dynamic model of straddle-type monorail vehicle with single-axle bogie, the model of electro-hydraulic actuator is established, and the adaptive neural fuzzy inference system proportional–integral–differential (adaptive fuzzy inference system proportional–integral–differential) is designed. The simulink results show that the adaptive fuzzy inference system proportional–integral–differential control active suspension can effectively reduce the root mean square value and peak value of the lateral acceleration, vertical acceleration, roll angle acceleration, pitch angle acceleration, and yaw angle acceleration of monorail vehicles compared with the passive suspension. The active suspension of electro-hydraulic actuator can effectively improve ride comfort of the straddle monorail with single-axle bogie.

Theoretical Derivation of Gauges for Straddle-type Monorail Vehicle

The theoretical model of the straddle-type monorail vehicle bogie is set up and the function of each component is introduced. The lateral and vertical displacements of carbody when the lateral and roll motion of carbody in the same/reverse direction are attained through theoretical derivation, which can be put into the calculation of the vehicle gauge. A computational program is written to simulate the corresponding results under specific parameters. The correctness of the method to calculate the monorail vehicle gauge is verified.

Study on Dynamic Response of Straddle-Type Monorail Vehicle with Single-Axle Bogie Under Curve Condition

This paper is concerned with the dynamic response of straddle-monorail with single-axle bogie under curve condition. A 15 degrees-of-freedom(DOF) dynamic model is established for straddle-type monorail vehicle with single-axle bogie, which consists driving wheels, steering wheels and stabilizing wheels. The motion equations of the straddle-type monorail vehicle are derived using the Lagrange's equation, and the wheel-rail contact model and the curving track beam model are created. Compared with the test results, the accuracy of the method is verified. Finally, the influence of curve radius, curve superelevation rate, number of passengers and stiffness of driving wheels on dynamic response is discussed.

Curving Performance of Straddle-Type Monorail Vehicle with Single-Axle Bogies Based on Spatial Multi-Body Dynamic Analysis

Straddle-type monorail ,as a unique technology, energy saving and environmental protection, is different from the subway of urban rail transit system. In order to study the curving performance of a new type of the straddle-type monorail vehicle with single-axle bogies ,the three-dimensional spatial dynamics model which consists of the vehicle model and track model designis proposed by the multi-body dynamics soft ADAMS. The monorail vehicle dynamic model which consists of three types of tire -track contact model and the nonlinear model of the horizontal stop is established. Based on the dynamic model, the influences such as pre pressure and curve super-high rate parameters of the curve passing for the dynamic characteristics are discussed. The simulation results show that the suitable preload for the guide and stabilizer tires of straddle-type vehicle with single-axle bogies is 5KN and after selecting the appropriate pre-pressure, the super-high rate is recommended to be 8%-10%.

Improving curving performance of a straddle type monorail vehicle by using semi-active devices

Improving curving performance of a straddle type monorail vehicle by using semi-active devices

Abnormal wear analysis of straddle-type monorail vehicle running wheel tire

On the Chongqing’s straddle-type monorail train in China, serious abnormal wear of running wheel tires occurs in its routine use, leading to a series of safety, environmental, and economic concerns. To analyze the causes of abnormal wear, a dynamic model of straddle-type monorail vehicle with full consideration to the lateral behavior of running wheel tire was established using Lagrange equations and verified by Zhong’s model created using SIMPACK. Based on the boundary conditions provided in the dynamic model and the friction characteristics of tire and pavement, a finite element model of the running wheel tire was built and validated with vertical, lateral, and longitudinal stiffness tests of corresponding tires. The wear situations of each running wheel tire under extreme turning condition were described in detail with the contact behavior and an assessment was done based on the friction work and the friction work skewness value. Besides, the influence of slip angle, roll angle, and their combined effect on the abnormal wear of running wheel tire was analyzed. This research proposes that, reasonable matching of the slip angle and the roll angle is of engineering significance and it can reduce uneven wear of the running wheel tire.

RESEARCH OF NORMAL CONTACT STIFFNESS OF STRADDLE-TYPE MONORAIL TYRES BASED ON FRACTAL THEORY

The contact stiffness of on the rough surface of tread interaction (tire-track) ,a significant parameter for the tire-track contact surface, gives rise to direct influences on stiffness and noises of tyres. There is no sufficient theoretical support for the wheel face design due to lack of research on this parameter. To solve this problem, an innovative method based on the fractal theory and the Hertz contact theory is proposed to estimate tread interaction contact stiffness. The fractal theory model is established to research the influencing factors on normal contact stiffness on the tread surface. Finite element analysis and physical tests have been conducted to make comparisons about the model. According to research results, there is a non-linear relationship between the contact stiffness and the fractal dimension. The research provides theoretical basis for tyre dynamics of straddle-type monorail vehicles and design of the track contact dynamics.

Radial adjustment mechanism of a newly designed coupled-bogie for the straddle-type monorail vehicle

ABSTRACT The bogies of the Hitachi and Bombardier straddle-type monorail vehicles could not be in the radial state on the circular curve because of the constraints of their own structure or secondary suspension system. Therefore, a large load always existed on the guiding wheels, restricting the curve negotiation speed of the vehicle. Taking this as the starting point, this study aimed to propose a newly designed bogie, called the automatic radial coupled-bogie (ARC-bogie). The theoretical model of linear steady-state curve negotiation of the ARC-bogie was established to analyse the passive radial adjustment mechanism of the ARC-bogie, and the calculation method for the optimal coupled parameters required for achieving the radial state was proposed. To validate the theoretical model, the dynamic performance of the ARC-bogie and the influence of coupled parameters were analysed by dynamic simulation. The result showed that the coupled rotary stiffness could make the ARC-bogie achieve the radial state automatically on the circular curve under reasonable matching between the secondary suspension system and the coupling mechanism. Moreover, the maximum radial force of the guiding wheels decreased obviously, and the curve negotiation safety of the vehicle improved remarkably. Finally, a scheme for the coupling mechanism of ARC-bogie was proposed.

Improving curving performance of a straddle-type monorail vehicle by using semi-active devices

This paper is concerned with improving the curving performance of the monorail vehicles which are one of the modern mass transport systems, by using semi-active magnetorheological (MR) dampers. Con...

Analysis of Running Stability and Tire Wear of Monorail Vehicles

Based on the movement state of straddle-type monorail vehicle and the force state of wheels, the theoretical model is established, and the dynamic simulation software is used to analyze the anti-overturning stability of guide wheels and stabilizer wheels of straddle-type monorail vehicle under pre-pressure. Three layout schemes of guide wheels and stabilizer wheels are established, and the motion state of straddle-type monorail vehicle under three schemes is compared and analyzed. It is found that the motion state of monorail vehicle is mainly limited by the rolling stiffness and the shaking head stiffness of the vehicle itself. By increasing the rolling stiffness, the roll angle of the vehicle can be reduced, so as to reduce the load variation and speed difference of the running wheels and reduce the wear of the running wheels. Over-increasing the shaking head stiffness can reduce the side slip angle of the running wheels, so as to reduce the side slip of the running wheels and reduce the wear of running wheels.

Dynamic Response of the full-scale Straddle-type Monorail Vehicles with Single-axle Bogies

The research on vibration response on random pavement is conducted to evaluate the riding stability and comfort of a new straddle-type monorail vehicle with single-axle bogies. The topology of straddle-type monorail vehicles with single-axle bogie is analyzed, and the full-scale dynamic model of single-axle bogie straddle-type rail transit vehicles of 34 degree of freedom and the tire-track beam contact model are established. Based on the dynamic model, the random vibration influence characteristics of vehicles of different velocities and tire stiffness are analyzed. Based on the research the riding stability and comfort are reduced with the increase in velocities and tire stiffness. The vertical stability is lower than the horizontal one with the vehicle with the same velocity and mass. This is because that the vertical vibration has a larger amplitude ratio than that of the horizontal vibration. No change is caused on frequency phase with the changes on stiffness. But certain change is made on amplitude. The frequency response is reduced with the increase in stiffness, leading to better stability and riding comfort. DOI: http://dx.doi.org/10.5755/j01.mech.25.1.21931

Dynamic parameters optimization of straddle-type monorail vehicles based multiobjective collaborative optimization algorithm

ABSTRACTThe dynamic parameters of Straddle-type monorail vehicles with single-axle bogies are optimised by utilising the multi-body dynamic method. The dynamic parameter optimisation is conducted aiming at the curve negotiation properties, comfort and tire eccentric wear of monorail vehicles. The optimisation model is established with software ADAMS and modeFRONTIER and the Sobol is adopted for sensitivity analysis to acquire the optimised parameters. Finally, the multiobjective collaborative optimisation algorithm is utilised for optimised analysis. According to the results, the proposed method can conduct multi-objective optimisation to the monorail vehicles in a successful way. The curve negotiation properties and comfort are improved, and the tire wear is reduced with dynamic parameters after optimisation. Especially, a conversion strategy of the consistent objective function is proposed aiming at multiobjective nonlinear convergence.

Dynamics Study of Straddle-Type Monorail Vehicle With Single-Axle Bogies-Based Full-Scale Rigid-Flexible Coupling Dynamic Model

The longitudinal drawbar and the lateral stabilizer bar of straddle-type monorail vehicle with the single-axle bogies have relatively long structure size. The multibar system leads to deformation during the driving process due to impact loads, even leads to influence on the dynamic characteristic of the hauling mechanism as well as the riding comfort of the whole vehicle. To evaluate the dynamic behavior of straddle-type monorail vehicle with single-axle bogies accurately, a full-scale rigid-flexible coupling multibody dynamics method is proposed based on multibody dynamics and finite element (FE) theory. The modal synthesis method is adopted to establish flexible multibody dynamics of the single-axle bogies. And then rigid-flexible coupling dynamic model of the straddle-type monorail vehicle is established with the ADAMS software. The validity of the full-scale model is verified. Finally, the influences of vehicle velocity, passenger mass, curve radius and the number of axles on dynamic characteristics are discussed.

Study on Main Factors of Walking Tire Wear in Straddle Type Monorail Vehicle based on ADAMS/Tire

Study on Main Factors of Walking Tire Wear in Straddle Type Monorail Vehicle based on ADAMS/Tire