The Study Of The Instrumented Wheelset Based On TDC Technology

Along with the high speed railway speed increasing, the accurate measurement of wheel rail force is very important. Wheel rail force testing for vehicle dynamics and the theory of derailment research has important significance. In wheel rail force many detection methods, instruments wheelset detection method is the most accurate and most direct detection method of wheel rail force. Instrumented wheelset wheel by direct detection element is, only need to monitor the web certain functions can realize continuous measurement. As a result of the reason of track irregularity, the working process of the vehicle, wheel rail force is non-stationary, time-varying, at the same time, the wheel rail force generated by the wheel by wheel turning angle strain effect. Instrumented wheelset measurement accuracy is affected by many factors. A wheel speed, wheel, patch technology, uniformity of the contact point position variation and external disturbances. Not only that, due to the high speed EMU running speed is high, the car under the strong electromagnetic field condition is complex, highlights the traditional instrumented wheelset technology precision and anti-interference of deficiency. The article is aimed at these problems, the main work is as follows:1.First analysis of the lateral force, vertical force and vertical force caused by the bending moment on the wheel web plate strain effect. Studied at the same radius group bridge eliminates harmonic method. In order to make the instrumented wheelset measurement precision is improved, the number of bridge, bridge phase difference and the need to eliminate the harmonic component order relation. Established by a transverse force, vertical force and moment caused by the action position under the common action of web plate strain in the nonlinear equations. And the simplified equation, the equation to eventually be able to deduce the analytic solution.2.Based on the conventional instrumented wheelset technology present situation, this paper adopts TDC technology as the core of the instrumented wheelset method. It is the time interval measurement module based on, through the external circuit compensation and signal conditioning, to obtain the high accuracy and low power consumption. Design including TDC measurement module and a peripheral circuit, four bridge mode group bridge mode, TDC discharge capacitor selection, crystal and comparator design, selection and design of the TDC control module. 3.Based on the Nano wireless transmission module of high integration, stability, design of TDC measurement system transmission module. Design of a set of application layer protocol, to realize data unpacking and checking function. Design for instrumented wheelset system operators to use PC applications. Can real time under various configurations, acquisition order, also can view real-time data collection, the corresponding data processing.4.Because of custom instrumented wheelset and standard instrumented wheelset are slightly different, measured by strain is sensitive gate covering the range of average strain, it is very difficult to get such as finite element method calculation of accurate node strain, which can lead to a test value and the finite element simulation of inconsistent values. Therefore, the program of the wheel web plate were instrumented wheelset static loading test, verify the correctness of the algorithm.