Ultra-low Frequency High Amplitude Vibration Displacement Real-time Processing Technology And Its Dsp Applications Research

With the rapid development of container transport, Container Crane (Crane) is increasingly large and high-speed as well as its vibration frequency is more low (ultra-low frequency (ulf) vibration below 1 HZ) and vibration displacement is more large (hundreds mm). Those dynamic characteristics in terms of its own security performance is essential, The Net Crane Monitoring Assessment System(Net CMAS) developed by Shanghai Maritime University realizes the real-time analysis and calculation of large displacement with ulf vibration.Because of the technique brought out by Net CMAS .Because the Net CMAS system of this technology from Simulation theory to determine the parameters(parameters "tLen" which has impact of the low frequency components of the signal and time constants "Ï„"etc. )is not enough , in practical engineering signal processing due to the impact of noise and make it difficult to ensure high precision .So we do further research on the issues of calculation precision and parameter optimization by experiment in the paper. Because of the tremendous volume of data in the scene of monitoring and the real-time signal processing about calculation includes integral,so we study and adopt DSP(Digital signal Processor) which is suitable for a large amount of data processing to realize the technique.At first,this paper use standard signal generator to produce a series of single-frequency signals and presents optimal treatment option of the real-time processing technology of large displacement with ulf vibration through simulation analysis.When tLen=5s,collectivity error of 0.2-2Hz standard cosine signal is the least. Amplitude error between emulate displacement and theoretical displacement of all single-frequency signals are within 5%(9.02% of 0.3 Hz signal).The precision meets engineering requirement.Second,we analyze vibration signal from simulation devices and on-site testing. After processing, the amplitude error between simulation displacement and theoretical displacement of each frequence experimental signal is within 10%,meets engineering requirement.Meanwhile,simulation vibration displacement and displacement measured by displacement sensors basically the same, so the simulation result is good, the optimal treatment option of the real-time processing technology of large displacement with ulf vibration is certificated.At last,we use DSP to process single-frequency signals and vibration signal from simulation devices, according input acceleration signal amplitude, we get theoretical displacement which is basically same with simulation displacement signal amplitude, so the simulation result is good, the reliability of DSP hardware system is certificated.Based on the research.we identify the optimal treatment option of the real-time processing technology of large displacement with ulf vibration,and realize its DSP hardware. This simple and high precision method also can be applied to other targets low frequency vibration and has high practicality.