The Research Of A New Type Of Wheel Sensor

In recent years, China’s railway is in the process of rapid development. With the faster development, the mammoth railway transport needs higher security protection and efficient dispatching to develop steadily. The current situation of the domestic railway signal is track circuit as the mainstay and electromagnetic axle counting equipment as the auxiliary. We explore the possibility of developing a new wheel sensor, because conventional track circuit system is slowly being questioned in the safety and reliability. The sensor is designed to improve the reliability, and based on the principle of electromagnetic induction, using a combination methods of the phase modulation and amplitude modulation, to achieve not only can detect the wheels, and can achieve the purpose of accurate positioning of the wheel center position.At the beginning of the paper the development status of axle counter equip-ment is Introduced, Researched and analysed the current domestic electro-magnetic type axle counter equipment. Sum up the advantages and disadvantages of them.In order to find a method that can detect the geometric center of the wheel, introduced the principle of eddy current sensor distance measurement simply, which indicated that the eddy current principle can be used to measure area. Then, studied the equilibrium conditions of the AC bridge, and Discussed the feasibility of measuring the center position of the low-speed operation train wheels accordance with the AC bridge and the eddy current principle. In addition, accord to the phase modulation wheel sensor measuring wheel position of the high-speed running train, i have found a way to measure the position of the train’s wheel accurately. Summed up the impact of the coil physical structure parameters on the size of the generated magnetic field, and determine the physical parameters of the sensor coil by experimental and theoretical exploration.At last built the actual excitation generating circuit and a signal processing circuit, and analysis and simulation have be done for these circuits detailedly. The circuit mainly includes the excitation signal generating circuit of two sensor coils, a square wave generator circuit, the two sensor output signal demodulation and the AC amplifying circuit.