Research Of Pressure Testing System Based On Train Fundamental Brake System

Stable fundamental brake system guarantees that the train can run on the railway safely. With the increasing speed of the train, a study on the fundamental brake system is becoming more and more important, especially on the brake shoes and brake pads. As the executive components of fundamental brake system, whether the brake shoes and brake pads can work normally is the important prerequisite for the train braking. Therefore, the pressure test of brake shoes and brake pads is very necessary. In addition, with the rapid development and wide application of virtual instrument in the testing field, it is absolutely to achieve the sharing of hardware and software resources by using the virtual instrument technology, and then various test systems can be built fast and easily.On the basis of a full study of fundamental brake system, this paper introduces the characteristics and working principle of brake shoes and brake pads. Combined with the related railway standards at home and abroad, pressure test standard for brake shoes and brake pads is formulated. Focus on the pressure test in this paper, the pressure test system on brake shoes and brake pads is designed by using virtual instrument. The design of pressure instrument is divided into two parts: hardware design and software design. The hardware design mainly includes the design of pressure transducers and their sectional fixtures. With the deep research of pressure transducer, this paper uses strain gauge pressure transducer to test the pressure of brake shoes and brake pads, and the pressure transducers and their sectional fixtures which meet the test requirement are designed according to the structure characteristic of brake shoes and brake pads. In addition, the signal conditioning module and data acquisition module are selected. The software is designed by using "three layers" structure. According to the pressure test requirements of brake shoes and brake pads, the "three layers" structure is defined as system user layer, data layer and data management layer. Through the realization of multiple threads, the three layers of this testing system can execute parallel and transfer data through the data queue and LV2 global variables with each other. This structure can ensure real-time testing and management. Each layer uses the event-loop-state machine to program. Finally, the test instrument is integrated. According to the pressure test standard of brake shoes and brake pads, pressure test on the brake shoes and brake pads would be in progress. Comparing with the experimental results, the braking ability of fundamental brake system can be evaluated.Through the design and development of pressure test system for brake shoes and brake pads, this paper studies the braking performance of brake shoes and brake pads fully, and establishes the evaluation standard for the pressure test of brake shoes and brake pads. It is of great significance to evaluate the braking ability of fundamental brake system. In addition, this pressure test system developed by using virtual instrument technology makes itself become open and extensible. It is a new thought and method to popularize and develop this kind of test instruments.