Attitude Control Research Of The End Of Armoured Photoelectric Composite Rope Applied To Core Sample Drill For Deep Seebed Shallow Strata

To ensure the photoelectric composite cables that used in deep-sea drilling have not been damaged becomes one of the key factors that ensuring the deep core sampling drill can successfully complete the expedition mission. At present, there is little research about the attitude control of communications and power transmission cable during the equipment operation at the domestic. In the actual operation, the release/recovery control and the attitude control of the photoelectric composite rope are more dependent on the practical experience of marine scientists, for there is no accurate control scheme from the theoretical calculation. What’s more, the cable kinks loosen occasionally during the operation, which increased the risk of scientific research equipment and restricted the smooth completion of the scientific research task in some extent.This paper mainly focuses on the armored photoelectric composite cable that applied to deep-sea drilling rig. Based on the force analysis of the cable in the actual operation, obtained the geometry equation of the cable under the largest positioning radius. By using MATLAB software and maple symbolic computation software, got the cable length of different operation depth in the sea under the largest positioning radius, which provided an important reference for the shortest cable length in different depth of water.In order to get more accurate distribution of the tension in the cable, the three-dimensional lumped mass model was established, acquired motion equations of lumped mass point and calculated the tension distribution of the cable in the different positioning radius. According to this result, several feasible programs have been put forward to hang buoyancy ball in the cable.Under the constraints of experiment conditions and complex, changeable Marine environmental, it is difficult to directly observe the attitude of the cable at different solutions when the vessel moves. Therefore, in order to get intuitive attitude changes of the cable and the tension distribution of the cable, Adams virtual prototype model was established. After that, the proposed feasible programs have been simulated, and optimized it. Finally, the reasonable programs to control the cable have been got.It was proved that, the actual releases cable length from the catenary model, and the control scheme of the cable attitude from the three dimensional lumped mass model and the Adams model were very feasible.