Method And Implementation Of Synchro Signal Digitization

With the rapid development of electronic technology and automatic control theory, control system is gradually changing from analog signal processing to digital signal processing. As an important parameter to be controlled in some control systems, angle signal processing is also changing from analog style to digital style with high performance. In order to achieve high performance digital control, the output signals of Synchro should be digitized in the system using synchro as angle sensor.Previous digital conversion methods of synchro signals include phase shifting coding, successive approximation coding and Scott transformer plus tracking coding, etc. However, some of these methods have low accuracy, some have weak anti-interference ability, some drift easily, some has low real-time performance, and some are costly. This thesis aims to find a cost-effective solution and finally implement the solution by studying the methods of synchro signal digitized conversion and their characteristics.Specifically, this thesis uses operation and conditioning circuits that consist of operational amplifiers and analog multiplier as digital front-end part. After a series of processing such as sampling, differential comparison, subtraction and division operation for the three-channel synchro output signals and the excitation reference signal, the sinusoidal signal of angle value is measured and the quadrant logic signals will be obtained, and then after A/D conversion, filtering correction, and output encoding, the digital value of the angle is obtained as the result of the conversion.Finally, synchro signal digital conversion system is tested by test system based on digital/synchro signal conversion module and a separate developed test software based on PC computer, the test results verifies the feasibility of the method. Ideas and measures are also proposed for further improvement.