为降低卫星在发射过程中受到的动态载荷,提出一种采用磁流变阻尼器的新型半主动整星隔振平台。建立隔振平台的动力学模型和柔性卫星隔振系统总体的动力学模型。将LQG最优控制和模糊控制技术相结合应用于半主动整星隔振系统,以卫星振动响应能量和作动器输入能量的加权和最小作为最优控制目标来确定最优控制力,并采用预测状态法进行时滞补偿。以最优控制力和磁流变阻尼器的实际出力作为输入变量,以磁流变阻尼器的控制电流作为输出变量设计模糊最优控制器。仿真分析结果表明:新型半主动整星隔振系统采用模糊最优控制时,在卫星轴向和横向方向上都可取得良好的振动控制效果,并且控制效果明显优于被动控制和限幅最优控制。
When a satellite is launched, it will afford a very high dynamical load. To decrease these dynamical loads, in this paper, a new semi-active whole-spacecraft isolation platform with Magneto-rheological (MR) dampers is proposed. Dynamical model of isolating platform and the whole flexible satellite isolating system is built using Newton-Euler method. LQG optimum control and fuzzy control technique was applied to the whole-spacecraft isolation system, in which the optimum control force was determined by optimizing the weighting sum of the energy of the satellite vibration response and dampers' actuating force. Using the optimum control force and MR dampers' actual force as the input and control electricity imposed on the damper as an output variable, a fuzzy optimal controller is designed and simulated. The result obtained shows that, the performance of vibration attenuation of the satellite isolating platform with a fuzzy optimal control method in the axial and lateral direction is effective and better than passive control strategy and clipping-optimal control method.