Probabilistic seismic stability of three-dimensional slopes by pseudo-dynamic approach

Probabilistic analysis is a rational approach for engineering design because it provides more insight than traditional deterministic analysis. Probabilistic evaluation on seismic stability of three dimensional (3D) slopes is studied in this paper. The slope safety factor is computed by combining the kinematic approach of limit analysis using a three-dimensional rotational failure mechanism with the pseudo-dynamic approach. The variability of input parameters, including six pseudo-dynamic parameters and two soil shear strength parameters, are taken into account by means of Monte-Carlo Simulations (MCS) method. The influences of pseudo-dynamic input variables on the computed failure probabilities are investigated and discussed. It is shown that the obtained failure probabilities increase with the pseudo-dynamic input variables and the pseudo-dynamic approach gives more conservative failure probability estimates compared with the pseudo-static approach.

基于RBF积分滑模的无人艇集群协同路径跟踪控制

为满足船舶护航、目标围捕等任务要求,文中提出了一种基于路径参数循环的欠驱动无人艇集群协同路径跟踪控制方法。在运动学设计方面,结合视线制导与一致性算法,设计无人艇集群协同制导律,得到闭曲线上对称的编队队形,实现对目标点进行围捕。在动力学设计方面,考虑动力学模型不确定性及传统滑模导致的抖振问题,利用神经网络逼近特性和饱和函数,设计基于自适应径向基函数神经网络的分布式积分滑模控制器,保证无人艇能够精确跟踪制导信号,从而提高系统抗干扰性和路径跟踪精度。Lyapunov稳定性分析证明了闭环系统误差是全局渐近稳定的。仿真结果表明了所提出集群协同控制方法的有效性。