Research On Wheel/Rail Loads Wireless Test System

With the development of the high-speed railway China's railway transportation is now developing towards high speed, overloading, massive carry and high density. Wheel/rail force testing is the very important tache of vehicle dynamics theory and practice, instrument wheelset technique is the most direct and efficient method for measurement of wheel/rail forces. Using instrument wheelset as the force sensor to test wheel/rail force has the maximal precision of all wheel/rail force testing measures. Using instrument wheelset as the force sensor to test wheel/rail force has the maximal precision of all wheel/rail force testing measures. The accurance of the instrumented wheelset is influenced by the inequality of the wheel, the technics of sticking the strain gagues, rotate speed of the wheel, and the change of position of the wheel/rail contact point. The paper based on the optimal circuit bridge combination and the best position of stick strain piece, designed a accurate small cubage wireless test system.The paper introduced the framework,software,hardware and control method of the test system, and described and calculate the hardware parameter of the AC modulation and demodulation,auto-zero. In the system installed the whole amplifier and A/D sample processing on the wheelset, and transmitting the data by wireless, don't like the traditional method of signal acquisition,transmission and processing unit is transmitting strain electrical signal output of strain-guage transducer with manifold ring. It reduced the cost, easy to connection,increase the accuracy. The wireless data transmit system used the module CC2430 by protocol Zigbee. ZigBee is a new protocol of short distance data transmit, this technology has very low complexity, low-cost, low consumption and low rates. Test the system in practical measuring and analyzed the data , reach the system accuracy.