中文摘要：

由二个单个万向节的控制时刻旋转罗盘(SGCMG ) 的太空船 underactuated 的态度控制问题被调查。spacecraft-SGCMGs 系统的态度动力学的小规模的本地可控制性(STLC ) 经由非线性的可控制性理论被分析。由二非同轴的 SGCMG 保证太空船态度的 STLC 的条件作为输入与 SGCMG 的动量被获得，当整个系统的全部的尖动量是零时，暗示太空船态度是 STLC。而且，我们的结果显示在零动量的限制下面，完整的态度稳定为用二非同轴的 SGCMG 的一只太空船是可能的。为二同轴的 SGCMG 的案例，太空船的 STLC 性质不能是坚定的。在这种情况中，到稳定控制法律的以前的完整的态度的改进，要求零动量的专横，被建议说明 SGCMG 的奇特并且提高稳定的州的性能。数字模拟结果表明新控制法律的有效性和优点。

英文摘要：

The attitude control problem of a spacecraft underactuated by two single-gimbal control moment gyros （SGCMGs） is investigated. Small-time local controllability （STLC） of the attitude dynamics of the spacecraft-SGCMGs system is analyzed via nonlinear controllability theory. The conditions that guarantee STLC of the spacecraft attitude by two non-coaxial SGCMGs are obtained with the momentum of the SGCMGs as inputs, implying that the spacecraft attitude is STLC when the total angular momentum of the whole system is zero. Moreover, our results indi- cate that under the zero-momentum restriction, full attitude stabilization is possible for a spacecraft using two non-coaxial SGCMGs. For the case of two coaxial SGCMGs, the STLC property of the spacecraft cannot be determined. In this case, an improvement to the previous full attitude stabilizing control law, which requires zero-momentum presumption, is proposed to account for the singu- larity of SGCMGs and enhance the steady state performance. Numerical simulation results demonstrate the effectiveness and advantages of the new control law.