Study On Performance Of High-speed Maglev Vehicle Running On Small Radius Curve

The high-speed maglev vehicle is one of the 20th century technique inventions. Since the 1960's, some thorough researches and repeated-test trials about two kinds of magnetic levitation techniques, that is, Electro-Magnetic mode and Superconductive mode, have been carried on in Germany and Japan, resulting to make great progresses which get more and more focus from all countries in the world. In order to shorten the gap of magnetic levitation transportation with developed countries like Germany and Japan, Chinese Government has established the High-speed Maglev Vehicle Development (I) as a part of national 863 developing program ( Source: Changchun Railway Vehicle Co., Ltd), which will promote the creative researches in the Chinese-made maglev vehicle development.The high-speed maglev vehicle (maglev vehicle for short as follow) is suspended and guided in the air by electromagnetic suspensions, which realizes the non-contact between wheels and rails, and then is hauled by linear synchronous electric-machines. The maglev vehicle is mainly composed of carbody and walking assembly, in which walking assembly is the flexible chain structure of levitation and guidance modules and levitating framework, and carbody is multi-supported with walking assembly through bolsters and air-springs.There are the following difficulties in this topic study: First, maglev vehicle is a complex dynamical system which is integrated the interactions with mechanics-electromagnet-control; Secondly, because of maglev rail gauge (2200mm) and distributed-type of maglev rail-wheels, the curve-negotiation performance is needed to be analyzed based on the novel guidance principle; Thirdly, non-contact guidance requires that maglev rails must be continued smoothly, especially the even more precision is necessary for the min. radio curve.For solving the above problems, with the collaborative platform of simulation and design technologies, the maglev vehicle is divided into three classes of elementary models, that is, maglev unit, levitating frame and carbody. According to maglev railway curve design, the sectional cubic-splines are joined in MATLAB, which are then fitted smoothly by the B-spline technology in ADAMS, and are examined by the virtual cruise of maglev unit to make sure the correctness of maglev curve. As the requirements of specific researches, half-vehicle, full-vehicle and 3-vehicle trainset model are assembled with the three elementary modules, the negotiations of that traveled on small radius curved-track are simulated and the maglev guide principle is analyzed.From the contrast analyses between the calculated values and simulated ones, model and simulation result are basically correct, for example, the both calculations of the geometric relations between carbody and walking assembly (the link yaw angle and bogies' lateral displacement, etc.) are very close to each other. Simulation analysis of full-vehicle and 3-vehicle trainset running on various kinds of curves indicate that rhombus stiffness of maglev bogie have a sensitive effect to lateral electromagnet forces, while the lateral displacements of bogie result in unloading problem in end maglev units. In a word, all above simulation works would help further researching the dynamic performance of Chinese-made maglev vehicle and have certain guidance significance for maglev vehicle design in theory.