, pp.83-88 http://dx.doi.org/10.14257/astl.2016. Dynamic and Decoupling Analysis of the Bogie with Single EMS Modules for Low-speed Maglev Train Yougang Sun* 1, 2, Wanli Li 1, Daofang Chang 2, Yuanyuan Teng 2 1 School of Mechanical Engineering, Tongji University, 201804, China 2 College of Logistics Engineering, Shanghai Maritime University, 201306, China 1989yoga@tongji.edu.cn Abstract. In order to analyze the decoupling capacity of the bogie of low speed maglev train, a dynamic multi-degree model of rising, falling, nodding and rolling movement of the maglev bogie is built. A single maglev bogie decoupling test platform is established. The experimental test results are included to demonstrate the decoupling capacity of the low-speed maglev train bogie and provide an important evidence for simplifying the whole train suspension control into single EMS Module suspension control. Keywords: decouple; low speed maglev train; dynamics; bogie; single EMS module. 1 Introduction Low speed maglev transportation technology with prominent advantages of the low operating noise, small turning radius, strong climbing ability and the less maintenance costs is becoming a new type of urban rail transit [1-3]. The bogie frame is the core component of the maglev train s operation and control system. The characteristics of the bogie frame are not only related to the safety and comfort of the vehicle, but also have a decisive influence on the design of the suspension control algorithm and the rail system [4]. So we need to conduct a thorough study of the characteristics of the bogie frame. Fig. 1. Structure of the MAGLEV train ISSN: 2287-1233 ASTL Copyright 2016 SERSC
Fig. 2. Structure of the maglev bogie frame In the world, the low-speed maglev trains adopt different types of anti-rolling mechanism as bogie frame. South Korean UTM-02 maglev trains use an anti-roll sill with a suspension module to realize the anti-roll decoupling [5]. But the maglev trains of the commercial operation line in Inchon use the steeve type anti roll decoupling mechanism [6]. In China, most of the middle and low speed maglev test vehicles use the steeve type anti roll decoupling mechanism [4, 7-8]. At present, there is little research on the structure decoupling of the low speed maglev bogie frame structure. The kinematic requirements of single bogie frame to realize the mechanical decoupling based on the D-H transform is proposed by Zhang Kun [9] and Zhang Gen [7] etc.. But they didn t figure out the bogie frame s dynamics analysis. Jiang Haibo [10] etc. analyzed the working principles of the anti-roll decoupling mechanism of bogie frame, and analyzed the design requirements of the decoupling mechanism according to the motion relationship between bogie frame and the rail. In this paper, the dynamic multi-degree model of rising, falling, nodding and rolling movement of the maglev bogie is built and decoupling capability of the low speed maglev bogie frame is analyzed by experimental test. 2 Low-speed Maglev Train Bogie Frame Structure The low speed maglev train system adopts the distributed structure. The vehicle body includes two parts, which are the carriage and the bogie frame. Each carriage is supported by 3-4 identical but independently controlled bogie frames, and the bogie frame and carriage are connected by an air spring. The physical structure of the bogie frame is shown in Figure 2. To the bogie frame of the low speed maglev train, the motion of the left and right modules in the movement process must be decoupled. The so-called decoupling refers to the relative position between the left and right modules, which can be realized by the motion of the joints of the lateral roll. The bogie frame makes the interaction between 4 Single EMS Modules in a very small range, which can realize the stable of the whole bogie frame by the independent single EMS module control. 84 Copyright 2016 SERSC
3 Dynamic Modeling of Maglev Bogie Fig. 3. Dynamic model of the bogie frame The dynamic model of the bogie frame is shown in Figure 3. Assume the bogie frame as a rigid body, it can be simplified as a vibration system composed of two rigid bodies, which are connected with each other by the elastic damping element (K b, C b ). Each rigid body has three degrees of freedom, which are ups and downs, nodding and rolling. The vertical levitation force of the electromagnet in Single EMS Module is equivalent to the spring damper suspension (K p, C p ), which means to linearize the suspension force at the equilibrium point. According to Figure 3, we can get the whole bogie dynamic equations in the directions of ups and downs, the pitch and lateral roll. 2 2 2 ml zl Fli ml g Cp (2 zl Wli ) K p (2 zl Wli ) i1 i1 i1 2 2 2 mr zr Cp (2 zr Wri ) K p (2 zr Wri ) Fri mr g i1 i1 i1 2 2 Jll CP[2 l1 l l1 ( Wl 1 Wl 2)] K p[2 l1 l l1 ( Wl 1 Wl 2)] ( Fl 1 Fl 2) l2 2 2 Jrr ( Fr 1 Fr 2) l2 CP[2 l1 r l1 ( Wr1 Wr 2)] K p[2 l1 r l1 ( Wr1 Wr 2)] 2 2 2 2 J ll Cb[( l lb ) l 2 llb l ( l lb )( zl zr )] 2 C l Kb[( l lb ) l 2 l lbl ( l lb )( zl zr )])] 2K l 2 2 2 2 J rr Cb[( l lb ) r 2 llb r ( l lb )( zl zr )] 2 C r Kb[( l lb ) r 2 llb r ( l lb )( zl zr )])] 2K r Copyright 2016 SERSC 85
4 Test for the Bogie Frame s Capacity of Decoupling 4.1 Test Philosophy Sensors and jacks are applied to the bogie frame which has shown in Fig.5. Jacks are adjusted to make the four corners of the bogie frame in one plane. Then, one of the four corners will be jacked up from 0mm to 25mm and the data of the pressure sensors and the displacement of the bogie beam can be read. The variation of the four forces and the four displacements can be obtained by jacking up the four corners one by one and the degree of coupling can be obtained, while the capacity of decoupling can also be got. Fig. 4. Test platform 1 jack, 2 pressure sensor, 1234 displacement sensor 4.2 Test Results In order to analyze the influence of the pivot on the displacements and loads of each point, the initial value of the displacements and the loads will be subtracted and listed in table 1. According to table 1, when pivot 1 is being jacked up, the variation of the diagonal pivot s load is in accordance with the variation of the pivot s load and the variation of the adjacent pivots are also in accordance. The displacement of pivot is quite big while the other three pivots are quite small (all about 1.0mm), which is satisfying to the decoupling requirements. The results for the pivot 1 and the other three pivots are quite similar. So, we only give the test results of pivot 1 in this paper. 86 Copyright 2016 SERSC
Table 1. The vertical displacement change table-- pivot 1 load NO. Displac ement increme nt (mm) Stres s (kn) Point 1 Point 2 Point 3 Point 4 Displa Displa Displace Stress Stress cemen Stress cemen ment (kn) (kn) t (kn) t (mm) (mm) (mm) Displa cemen t (mm) 1 2.18 0.23 2.18-0.17-0.01 0.22 0.01-0.26 0.03 2 5.82 0.48 5.82-0.45-0.01 0.53-0.03-0.53 0.10 3 10.44 0.71 10.44-0.68-0.01 0.76-0.07-0.73 0.19 4 15.07 0.86 15.07-0.76-0.01 0.86-0.09-0.84 0.21 5 20.18 1.11 20.18-1.02-0.01 1.09-0.14-1.05 0.36 6 25.33 1.44 25.33-1.35-0.02 1.43-0.22-1.39 0.61 The test results show that vertical displacements of single EMS modules are not interacting with each other in a certain range, decoupling capacity of the bogie is excellent 5 Conclusions (1) A dynamic multi-degree model of rising, falling, nodding and rolling movement of the maglev bogie is built. The simulation proves the decoupling capacity of the bogie in theory. (2) The experimental test results demonstrate the single EMS modules on bogie are not interacting with each other, which can realize the stable of the whole bogie frame by the independent single EMS module control. References 1. Thornton, R.D.: Efficient and Affordable Maglev Opportunities in the United States [J]. Proceedings of the IEEE, 2009, 97(11): 1901-1921. 2. Lee, H. W., Kim, K.C., Lee, J.: Review of Maglev Train Technologies [J]. IEEE Transactions on Magnetics, 2006, 42(7): 1917-1925. 3. Liu, SK., An, B., Liu, SK., Guo, ZJ.: Characteristic research of electromagnetic force for mixing suspension electromagnet used in low-speed maglev train [J]. IET Electric Power Applications, 2015, 9(3): 223-228. 4. Liu, Y. Z., Deng, W., Li, J.: Research on the Anti-rolling and decoupling characteristics of maglev bogies [J]. Journal of the China railway Society, 2014, 36(3): 37-41. 5. Yim, B. H., Han, H. S., Lee, J. K.: Curving Performance Simulation of an EMS-type maglev vehicle [J]. Vehicle System Dynamics, 2009, 47(10): 1287-1304. 6. Han, J. W., Kim, J. D., Song, S. Y.: Fatigue Strength Evaluation of a Bogie Frame for Urban Maglev Train with Fatigue Test on Full-scale Test Rig [J]. Engineering Failure Analysis, 2013, (31): 412-420. 7. Zhang, G., Li, J., Li, J.: Kinematics Study on Anti-roll Boom of Low-speed Maglev train [J]. Journal o f the China Railway Society, 2012, 34(4): 28-33. Copyright 2016 SERSC 87
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