DSP-Based Damage Detection Instrument For Hoist Wire Rope

Wire rope plays a vital part in production and living, it is also a kernel component of hoist system. In order to avoid accident caused by wire rope breaking, evaluating the damage condition of wire rope timely and accurately and ensuring wire rope is working under a secure condition are necessary. Thus, designing a wire rope damage detecting device with high performance has a significant meaning in the realm of ensuring personal safety.This paper has established the research plan of wire rope damage detecting according to the main damage characteristic of hoist wire rope and the principle of damage detecting. Through analyzing and evaluating current methods, the method of magnetic flux leakage(MFL) is regurd as the basic detecting principle. Space vector relationship of leakage magnetic field at the axial, radial and circular direction of wire rope has been found by modeling and MATLAB simulation analysis. According to the simulation results, a new front signal acquisition method of hall annular space array is proposed to measure leakage magnetic field.Signal acquisition unit combine sensor and high-accuracy AD convertor, it is also connected to DSP digital signal processing unit through SPI interface. In order to save enough storage space for data processing and signal recognition, AD convertors collect the sensors in the array of hall annular space separately and output the data independently. Through the methods of parameter calculation, circuit simulation and 3D modeling, the rationality of designing DSP digital signal processing unit and signal acquisition unit is verified. At the respect of data signal processing, a combinative algorithm is proposed which combine the advantage of improved mean filter without extreme value with the advantage of sliding window mean filter. Through the original sampling data comparing analysis by MATLAB simulation, the feasibility of combinative algorithm has good results in eliminating noise and enhancing signal visibility. In the end, the prototype of wire rope damage detecting is designed to be completedFollowing the designing principles of wire rope damage detecting bench, the wire rope rotation bench with the properties of frequency is designed and produced. Several groups and kinds of experiments based on the bench and detecting system have been made that are regard to internal and external broken wires. The damage datas based experiments are analyzd from the view of space vector relation, resultant amplitude and tri-axial phase. Finally, the relationship of leakage magnetic field inside and outside wire rope in those three aspects confirm the high accuracy, recognition rate and reliability in terms of broken wire recognition through several groups of experiments.Research and experimental data shows that DSP damage detecting system based on hall annular space array and its vector method in broken wire recognition have extensive application value.