基于改进人工势场法的救灾机器人路径规划

针对矿井障碍物复杂多变、救灾机器人采用传统人工势场法进行路径规划易陷入局部极小点的问题,提出一种基于改进人工势场法的救灾机器人路径规划方法。该方法通过在引力场中加入扰动场来改变引力场函数,使救灾机器人在陷入局部极小点时自主走出局部极小点;结合障碍填充法,通过对凹障碍物进行虚拟填充,形成新的障碍物并产生相应的斥力场函数,避免救灾机器人再次陷入局部极小点。仿真及测试结果验证了该方法的可行性及有效性。     

Tabu search algorithm combined with global perturbation for packing arbitrary sized circles into a circular container

The arbitrary sized circle packing problem （ACP） is concerned about how to pack a number of arbitrary sized circles into a smallest possible circular container without overlapping. As a classical NP-hard problem, ACP is theoretically important and is often encountered in practical applications. Based on the already existing Quasi-physical method, this paper proposes a hybrid algorithm named GP-TS which combines tabu search with global perturbation to solve the two-dimensional ACP. The Quasi-physical method is a continuous optimization method which is used to obtain a local optimal configuration from any initial configuration. The tabu search procedure iteratively updates the incumbent configuration with its best neighboring configuration according to some forbidden rule and aspiration criterion. If the configuration obtained by the tabu search procedure does not satisfy the constraints, the global perturbation operator is subsequently applied in order that the search jumps out of the current local optimum without destroying the incumbent configuration too much. After that, the tabu search procedure is launched again. GP-TS is performed by repeating this process until the stop criterion is met. Computational experiments based on 3 sets of representative instances show that GP-TS can improve many best known results within reasonable time.     

Second-order terminal sliding mode control for hypersonic vehicle in cruising flight with sliding mode disturbance observer

This paper focuses on the design of nonlinear robust controller and disturbance observer for the longitudinal dynamics of a hypersonic vehicle (HSV) in the presence of parameter uncertainties and external disturbances. First, by combining terminal sliding mode control (TSMC) and second-order sliding mode control (SOSMC) approach, the secondorder terminal sliding control (2TSMC) is proposed for the velocity and altitude tracking control of the HSV. The 2TSMC possesses the merits of both TSMC and SOSMC, which can provide fast convergence, continuous control law and hightracking precision. Then, in order to increase the robustness of the control system and improve the control performance, the sliding mode disturbance observer (SMDO) is presented. The closed-loop stability is analyzed using the Lyapunov technique. Finally, simulation results illustrate the effectiveness of the proposed method, as well as the improved overall performance over the conventional sliding mode control (SMC).     

大型观测有效载荷对空间站平衡姿态影响研究

空间站通常运行在力矩平衡姿态下。空间站上搭载大型天文观测有效载荷时,载荷运动会产生干扰力矩,对空间站平衡姿态会产生影响。针对搭载在空间站平台上的大型观测类有效载荷工作特点,建立了其运动补偿规律和扰动模型,将扰动引入空间站的平衡姿态动力学过程中,并进行了计算机仿真和分析。仿真结果表明,在设计的二次调节器和前馈控制器的作用下,转动有效载荷运动引起的姿态角、姿态角速率变化等控制在一定的范围内,且有效载荷的跟踪观测效果较稳定。     

光伏电池最大功率点跟踪方法比较

根据太阳能光伏电池的工程数学模型,在Matlab环境下建立了光伏电池仿真模型,分析了光照强度和温度变化对光伏电池输出特性的影响。针对扰动观察法采用固定的扰动步长而难以获得较高跟踪精度和响应速度的问题,提出了一种基于变步长的改进的扰动观察法,并通过对光伏电池控制系统进行仿真,比较了这2种最大功率点跟踪方法的仿真曲线。结果表明,采用改进的扰动观察法的光伏电池控制系统能更快速跟踪最大功率点,且在最大功率点处稳定性较好。     

对河口水库清淤施工工艺及扰动源强分析

对河口水库清淤保源工程是水源安全综合治理的重要组成部分.分析了清淤工程的陆域和水域施工工艺及工程环保措施,重点研究了链斗挖泥船施工时引起的污染物源强和污染物衰减过程,包括单只挖泥船影响范围和多个挖泥船的叠加影响,以及对取水口可能造成的影响,以期检验工程清淤船只施工工艺的合理性.     

改进正交试验法在调速器参数优化中的应用

对粤电集团某水电站机组建立仿真模型,采用改进正交试验法对该电站调速器参数进行优化,并对优化后的调节系统进行了频率扰动仿真试验.结果表明:参数优化后的调节过程性能得到明显改善,且用改进正交试验法优化调速器参数是方便、快捷和可行的.     

知识的属性扰动规律的不等式关系

知识的属性扰动引起知识规律的变化,这些变化的规律称为扰动规律.利用单向S-粗集和单向S-粗集对偶,给出属性扰动的知识规律的上规律.下规律的概念,并对知识规律与属性扰动的知识规律进行了讨论,提出了属性扰动知识规律(上规律,下规律)的不等式定理.     

基于抗扰动补偿的转台伺服系统准滑模控制研究

针对飞行模拟转台伺服系统中存在的内部和外部扰动.在分析它们对转台伺服系统影响基础上,采用线性连续准滑模控制(LCPSM)和状态立方反馈准滑模控制(SCFPSM)两种方法对转台伺服系统进行了杭扰动补偿控制,通过与传统PID控制方法和常规滑模变结构控制方法的比较证明准滑模控制方法对于转台伺服系统中的参数摄动和外部摩擦等扰动因素具有良好的抑制和补偿作用,消除了常规滑模变结构控制中的抖振现象.