The Development Of Ship Shaft Power Measurement Based On Photoelectric Sensor

In the ship transmission system, the measurement of the axis’torque and power is the important testing item in the ship test, the measurement of the axis’power has a pivotal role to the ship’test. So many kinds of testing system researches, which made by internal or international people, have a huge improvement. With the high-speed development of the productivity and social needs-people have the higher request to the ship of high reliability, high efficiency and low energy consumption, so they have the higher request to the shaft power measuring’ performance of ship. Based on the principles of phase difference measurement, the shaft power measurement of ship was designed in this system, by adopting optoelectronic switch, photoelectrical encoder.According to selection of the need devices in the system. And then, the optical signals, which get through optoelectronic switch and photoelectrical encoder, converted into periodic electrical signals. In the experiment, aiming at the problem that the photoelectric signal is weak and vulnerable, the system designs signal processing circuit, by using hysteresis voltage comparator circuit, realize signal amplification and waveform shaping to reduce dithering pulse and enviromental interference and ensure the measurement accuracy and reliability efficiently. In order to eliminate time shift and temperature shift, the project design a specific logical operation, which calculates in the EP1C6Q240C8, signal phase difference dealt with FPGA, transports to the single-chip megal28. In order to make the result more accurate, EP1C6Q240C8and Atmega128have a proper frequency external crystals each other.The signal phase difference was sent to upper computer, the program, including image processing algorithm and serial port communication, is implemented with VB6.0. Through the program,It realize the processing of data, display, data storage, graphic and other functions in upper computer, not only improving intelligence but also reduce the cost of the hardware resources.According to the experimentation and data analysis, the paper analied the stability and repeatability of the system to find that the system is of high measurement accuracy,good real-time performance,easy-control panel, portable,the system is suitable for the real-time and online power measuring not only in marine main engine but also in other mechanical transmission system.