Research For Multi-Axles Coordinated Adhesion Control Of Locomotive

With the deepening of China’s Reform and Opening, railway transportation takes a more important role in the country’s transport industry. Larger tractive power locomotive has been researched and developed to improve the freight efficiency by the railway department. It depends on the adhesion between wheel and rail to make full use of the great tractive power. To avoid the locomotive’s slipping and sliding and improve the adhesion utility ratio, the adhesion system must be equipped in the locomotive, and it is one of the core component of traction system. Most research of the locomotive adhesion control consider how to improve adhesion performance of every wheelset, but ignore the characteristics of the locomotive as a whole. In the traditional process of adhesion control, all of the wheelsets try to work in the optimum adhesion point, but the slip of any wheelset will affect other wheelset, and reduces the adhesion utility ratio. This treatise started from the characteristics of the locomotive as a whole, analyses relationship between wheelsets among the locomotive, designs a Multi-Axles Coordinated Adhesion Control system for locomotive.Firstly, a Multi-Axles coordinated and Multi-Layer distributed adhesion control method is designed. And this control system is divided into upper, middle and lower levels. The upper level is torque distribution layer, which responsible for the dynamic compensation of axle-load shift. The middle level is axle-coordination layer, it reduce the slip of locomotive, and increases the adhesion utility ratio. The lower level is adhesion control layer, it realizes the adhesion control of master axle and fellow axle.Secondly, separately designed the adhesion control system for master axle and fellow axle. Normally the first axle of locomotive is easier to slip in the traction condition. And it sets the first axle in the forward direction as master axle and others as fellow axles. Master axle try to find the maximum adhesion coefficient in this condition during the adhesion control, and fellow axle adjusts the traction torque based on the maximum adhesion coefficient which finds by the master axle.Thirdly, it implements a heavy load locomotive dynamic axle load-transfer compensation method. Locomotive is generally considered static axle load-transfer compensation. But the load-transfer becomes larger while the traction force is large, the lighter axle prone to slip, and affects the use of vehicle traction. Thus, taking into account the problem of axle-load impacting the adhesion force. In dry condition, the distribution of traction torque is based on axle-load, in the wet condition, combined the difference of master axle and fellow axle, it adjusts the method of torque distribution and realizes the axle-load compensation by change the traction torque, and increases the adhesion utility ratio in the low adhesion condition.Finally, it builds an adhesion control simulation platform which includes heavy locomotive multi-body dynamics model, adhesion control system and the traction power system. Normal locomotive model which we often used in adhesion control research is too simple, and is always used in the verification of logic of adhesion control method, but is hard to simulate the relationship between the axles, and can’t be used in the study of multi-axle adhesion control. This treatise builds a multi-body dynamics model of locomotive in the environment of SIMPACK, and simulates the designed Multi-Axles Coordinated Adhesion Control system by MATLAB/Simulink-SIMPACK co-simulation. And finished the simulation analysis of the adhesion control by this platform.