存在饱和输入的欠驱动船舶航迹跟踪控制

针对控制输入存在饱和限制的欠驱动船舶的航迹跟踪问题,提出鲁棒饱和控制方法。以船舶纵向速度和艏向角速度为虚拟输入,设计饱和运动学控制器,并引入二阶滤波器形式对控制器进行简化;利用反步法并引入Nussbaum型函数,设计饱和动力学控制器,以实现对任意光滑航迹的跟踪控制,并保证跟踪误差收敛至零点附近的一个有界区域内。仿真算例验证了设计方法的有效性和鲁棒性。     

基于APSO算法的公路光伏声屏障储充系统优化

为实现公路光伏声屏障发电系统的能源自洽，基于自适应粒子群算法提出了一套从光伏出力、蓄电池储能到充电桩用电的“光储充”容量配置方案。根据项目所在地的温度、辐射强度及光伏组件性能衰减规律建立光伏出力模型，结合公路光伏声屏障吸声降噪效果，计算光伏组件最佳倾角并获取该倾角下的光伏资源禀赋。基于光伏出力与负荷需求，获取蓄电池逐时荷电状态，利用雨流计数法和等效循环寿命法计算蓄电池的预估使用寿命，建立了涵盖初始投资、运行维护和设备更换3部分费用的成本模型，相较于传统固定寿命的成本模型更加具有实际意义。然后，以最小化总成本为优化目标，考虑系统的最小功率、占地面积、蓄电池荷电状态、系统负荷缺电率和系统弃能率5个约束条件，建立了公路“光储充”系统容量配置协调优化模型。采用自适应的粒子群算法，通过改进惯性权重提高了粒子的全局和局部搜索能力，得到了给定光伏板数量下蓄电池及充电桩的最优容量配置方案。结果表明：提出的公路“光储充”模型的能源自洽率达95%以上，对加快公路交通能源融合具有重要意义。针对蓄电池荷电状态，设定荷电状态全年处于0.2～0.8之间，防止了蓄电池的过充过放，显著提高了蓄电池的使用寿命；针对粒子...     

Design optimization of a torpedo shell structure

An optimized methodology to design a more robust torpedo shell is proposed. The method has taken into account reliability requirements and controllable and uncontrollable factors such as geometry, load, material properties, manufacturing processes, installation, etc. as well as human and environmental factors. The result is a more realistic shell design. Our reliability optimization design model was developed based on sensitivity analysis. Details of the design model are given in this paper. An example of a torpedo shell design based on this model is given and demonstrates that the method produces designs that are more effective and reliable than traditional torpedo shell designs. This method can be used for other torpedo system designs.     

Adaptive robust control for an active heave compensation system

Active heave compensation systems are usually employed in offshore and deep-sea operations to reduce the adverse impact of unexpected vessel’s vertical motion on the response of underwater instruments.This paper presents a control strategy for an active heave compensation system consisting of an electro-hydraulic system driven by a double rod actuator,which is subjected to parametric uncertainties and unmeasured environmental disturbances.Adaptive observer and discontinuous projection type updating law with bounded adaption rate are presented firstly to estimate the uncertain system parameters.Then a similar estimation algorithm is designed by using a multiple delayed version of the system to enhance the performance of parameter observation.A reduced order observer is also introduced to estimate unknown wave disturbances.Using the obtained uncertainty information,the resulting control development and stability analysis are implemented based on the Lyapunov’s direct method and back-stepping technique.The proposed controller guarantees the heave compensation error convergent to a bounded neighborhood around the origin.Simulations illustrate the effectiveness of the proposed control system.     

海底电缆铺设回泥面的水动力分析

针对实际电缆铺设工程成本过大及耗时太长的问题,基于理论分析和数值模拟对文昌海底电缆铺设回泥面进行比较分析。通过水动力分析软件Orca Flex建立电缆铺设的数值模型,重点讨论吊缆的吊放长度和施工船舶在不同阶段的航行速度对电缆安全性能的影响,根据电缆的最大有效张力和最小弯曲半径对电缆铺设提出相应的建议,得到的结论对实际工程有一定的参考价值。     

Central pattern generator based gait control for planar quadruped robots

In this paper, a gait control scheme is presented for planar quadruped robots based on a biologic concept, namely central pattern generator （CPG）. A CPG is modeled as a group of the coupled nonlinear oscillators with an interaction weighting matrix which determines the gait patterns. The CPG model, mapping functions and a proportional-differential （PD） joint controller compose the basic gait generator. By using the duty factor of gait patterns as a tonic signal, the activity of the CPG model can be modulated, and as a result, a smooth transition between different gait patterns is achieved. Moreover, by tuning the parameters of the CPG model and mapping functions, the proposed basic gait generator can realize adaptive workspace trajectories for the robot to suit different terrains. Simulation results illustrate and validate the effectiveness of the proposed gait controllers.     

海上半潜式浮式风机平台系泊系统对比研究

选取5MW-OC4深水半潜式浮式风机平台为参考模型,利用AQWA软件建立半潜式浮式风机平台模型,在频域范围内计算浮式风机平台运动响应,得到平台幅频响应曲线,以验证数值分析的可靠性。选取3种浮式风机平台系泊系统,对比研究系泊系统改变对浮式风机平台运动响应的影响规律,同时分析极端环境条件下单缆失效对浮式平台运动响应及系泊缆张力的影响。计算结果对浮式风机平台系泊系统的优化设计有一定的参考意义。