Precise Location By Radio Phase Detecting Technology

For the three locomotives' co-joint is indispensable in every coking plant, this problem-study aims at how to realize the chain auto-control of three locomotives' co-joint. After analyzing the status quo of coking locomotives both home and abroad, we bring forward such a radio phase detecting technology as could gain higher with less cost. According to this method, two transmitters should be installed respectively on the both side of the rail, which will send signals uninterruptedly. When the signals run on the rail, the radio receiver in the engine itself receives the signals from the two radio sending sets below. With the phase difference compared, the location of the engine can be confirmed. Choosing the appropriate frequency of the radio wave, precision of≤1 centimeter can be attained.Compared with the coding cable location system, our method can offer equivalent orientation precision and working reliability, while our method has an outstanding advantage of low cost. Usually, the cost of the coding cable location system is extremely high about 180,000-360,000 yuan. However, the equipments attached to radio phase positioning technology cost mere 10,000 yuan. By using our method, coding cables are of no use, so that at least 150,000 yuan can be saved.My main task is to design the hardware of the engine positioning system of the three locomotives' co-joint chain. First, I have made careful research and analysis of the theory and principle about radio phase-detecting positioning. By the simulation of circuits, I have decided the whole precept, schemed out circuits in every unit, among which are crystal surge circuit, modulation and demodulation circuit, and phase-detecting circuit. In the course of this problem-study, I mainly solve such three problems as below:1. To enhance the accuracy of the phase-detecting and overcome the blind area, I adopt two set circuits working alternately and gain the expected results.2. To lower cost and improve stability, I adopt the down frequency conversion technology and prove that it doesn't effect the accuracy of the phase-detecting, which has been confirmed by the experiments and simulations.3. To lower the complexity of the system, I have halved the receiving and sending circuits by using modulation technology.Through the efforts of more than one year, I have completed the main hardware design task, and gain sound results of modulation.The completion of this paper will enable the radio phase positioning technology in the high accuracy positioning system more easily universal.