A novel initiative mating device, which has four 2-degree manipulators around the mating skirt, is proposed to mate between a skirt of AUV （autonomons underwater vehicle） and a disabled submarine. The primary functi...A novel initiative mating device, which has four 2-degree manipulators around the mating skirt, is proposed to mate between a skirt of AUV （autonomons underwater vehicle） and a disabled submarine. The primary function of the device is to keep exact mating between skirt and disabled submarine in a badly sub sea environment. According to the characteristic of rescue, an automaton model is brought forward to describe the mating proceed between AUV and manipulators. The coordinated control is implemented by the TDES （time discrete event system）. After taking into account the time problem, it is a useful method to control mating by sinmlation testing. The result shows that it reduces about 70 seconds after using intelligent co-ordinate control based on TDES through the whole mating procedure.展开更多
This paper focuses on the problem of modeling and finite-time tracking control for mobile manipulators with affine and holonomic constraints. A reduced dynamic model is obtained by appropriately processing anne and ho...This paper focuses on the problem of modeling and finite-time tracking control for mobile manipulators with affine and holonomic constraints. A reduced dynamic model is obtained by appropriately processing anne and holonomic constraints, respectively. Then finite-time tracking controllers are designed to ensure that output tracking errors of closed-loop system converge to zero in finite time while the constraint force remains bounded. Finally, detailed simulation results are provided to confirm the effectiveness of the control strategy.展开更多
We study theoretically the effect of weak external magnetic fields on persistent spin helix states in semiconductor two-dimensional electron gases with both Rashba and linear-in-momentum Dresselhaus spin-orbit couplin...We study theoretically the effect of weak external magnetic fields on persistent spin helix states in semiconductor two-dimensional electron gases with both Rashba and linear-in-momentum Dresselhaus spin-orbit coupling.We show that in the presence of weak external magnetic fields, some basic properties of a persistent spin helix state,including the dispersion relation between the decay time and the magnitude of the wavevector, the maximum decay time and the value of the characteristic magnitude of the wavevector at which the maximum decay time occurs, will all depend sensitively on the directions of applied external magnetic fields.展开更多
文摘A novel initiative mating device, which has four 2-degree manipulators around the mating skirt, is proposed to mate between a skirt of AUV （autonomons underwater vehicle） and a disabled submarine. The primary function of the device is to keep exact mating between skirt and disabled submarine in a badly sub sea environment. According to the characteristic of rescue, an automaton model is brought forward to describe the mating proceed between AUV and manipulators. The coordinated control is implemented by the TDES （time discrete event system）. After taking into account the time problem, it is a useful method to control mating by sinmlation testing. The result shows that it reduces about 70 seconds after using intelligent co-ordinate control based on TDES through the whole mating procedure.
基金supported by the National Natural Science Foundation of China under Grant Nos.61273091and 61573177the Project of Taishan Scholar of Shandong Province
文摘This paper focuses on the problem of modeling and finite-time tracking control for mobile manipulators with affine and holonomic constraints. A reduced dynamic model is obtained by appropriately processing anne and holonomic constraints, respectively. Then finite-time tracking controllers are designed to ensure that output tracking errors of closed-loop system converge to zero in finite time while the constraint force remains bounded. Finally, detailed simulation results are provided to confirm the effectiveness of the control strategy.
基金Supported by the National Natural Science Foundation of China under Grant No.10874049
文摘We study theoretically the effect of weak external magnetic fields on persistent spin helix states in semiconductor two-dimensional electron gases with both Rashba and linear-in-momentum Dresselhaus spin-orbit coupling.We show that in the presence of weak external magnetic fields, some basic properties of a persistent spin helix state,including the dispersion relation between the decay time and the magnitude of the wavevector, the maximum decay time and the value of the characteristic magnitude of the wavevector at which the maximum decay time occurs, will all depend sensitively on the directions of applied external magnetic fields.
