舰载机着舰甲板运动误差及其补偿仿真研究

论述了舰载机着舰过程中的甲板运动扰动,分析了其对飞机着舰的影响,据此对舰载机着舰引导系统进行甲板运动补偿网络设计,并进行仿真,仿真结果表明,补偿网络明显的减小了飞机着舰的纵向误差,通过随即给的航母甲板运动初始相位进行仿真,说明补偿网络具有良好的适应性。     

铼(Re)对定向高温合金组织与性能的影响

以第二代定向柱晶DZ9合金成分为基础,调整Re含量,通过对三种不同Re含量的定向合金的研究,探讨了Re含量的变化对定向高温合金组织和性能的影响。结果表明:加入Re可提高合金的初熔温度和γ'相的回溶温度;Re的含量显著影响合金的γ+γ'共晶相形态和γ'相的尺寸和形态;增加Re含量,可提高合金的室温拉伸强度和合金的高温持久寿命。     

采用变速控制力矩陀螺的航天器姿态跟踪研究

研究了以变速控制力矩陀螺(VSCMG)作为执行机构的航天器姿态跟踪问题.建立了以VSCMG为执行机构的航天器姿态动力学模型, 引入一阶稳定的线性角速度滤波方程, 同时, 根据Lyapunov稳定性定理, 设计了闭环系统的控制律. 利用加权的最小范数解得到VSCMG的姿态控制输入矢量. 提出了表征VSCMG构型的新奇异度量, 在其基础上利用梯度法构建了VSCMG的零运动, 以回避VSCMG的构型奇异, 并使转子转速趋于期望值. 以四陀螺金字塔构型为例进行仿真,仿真结果验证了该算法的可行性和有效性.      

Failure treatment strategy and fault-tolerant path planning of a space manipulator with free-swinging joint failure

Aiming at a space manipulator with free-swinging joint failure, a failure treatment strategy and fault-tolerant path planning method is proposed in this paper. This method can realize failure treatment of a space manipulator with free-swinging joint failure through determination of the optimal locked joint angle and dynamics model reconfiguration. Fault-tolerant path planning is realized by the establishment of the degraded workspace with integrated kinematics performance (DWWIKP) and an improved A-Star (A1) algorithm. This paper has the following contributions. The determination of the optimal locked joint angle can ensure that the manipulator is able to continue follow-up tasks while maximizing the workspace of the manipulator after locking the fault joint. Underactuated control of a high degree-of-freedom (DOF) manipulator can be effectively solved through dynamics model reconfiguration. The analysis process of the dynamics coupling relationship can be applied to cases where the active joint and the passive joint are parallel or perpendicular to each other. The establishment of the DWWIKP can demonstrate the kinematics performance of the manipulator in both joint space and operation space comprehensively. The improved A1 algorithm based on the integrated kinematics performance index (IKPI) can search a fault-tolerant task trajectory that satisfies the requirements of reachability and the overall kinematics performance simultaneously. The method proposed in this paper is verified by a 7-DOF manipulator, and it is available to any DOF manipulator with free-swinging joint failure.     

干运转下连轴弧齿锥齿轮的瞬态热分析

为了模拟干运转下弧齿锥齿轮的温度场,根据齿轮啮合原理并考虑热量向轴的传导建立了连轴弧齿锥模型。在对热源、热传导和对流换热参数分析的基础上,建立了连轴弧齿锥齿轮瞬态热分析模型,得到了两种转速下的瞬态温度场和温升曲线,并与传统单齿模型的计算结果进行了对比。结果表明:5kr/min转速下的最终温升和温升速率相较于3kr/min转速下的结果明显更高,且两种转速的齿面温度之差沿啮合点向两端逐渐减小;在最初的5s内,单齿模型的计算结果与连轴弧齿锥模型基本一致,但随着时间的推移单齿模型的最高温升相比于连轴弧齿锥模型将更高。     

基于拉格朗日插值法的ATS射频信号衰减修正研究

对自动测试系统中射频信号通路的衰减修正进行了研究。为解决现有修正方法操作复杂、后期维护困难的问题,提出了基于拉格朗日插值的方法来实现射频信号衰减的修正,在保证修正数据准确度的前提下既减少了修正的工作量又降低了系统后期维护的难度,并通过算例和验证了该方法的可行性。     

Scientific Objectives and Payloads of Chinese First Mars Exploration

China plans to implement the first Mars exploration mission in 2020. It will conduct global and comprehensive exploration of Mars and high precision and fine resolution detection of key areas on Mars through orbiting, landing and roving. The scientific objectives include studying the Martian morphology and geological structure characteristics, studying the soil characteristics and the water-ice distribution on the Martian surface, studying the material composition on the Martian surface, studying the atmosphere ionosphere and surface climate and environmental characteristics of Mars, studying the physical field and internal structure of Mars and the Martian magnetic field characteristics. The mission equips 12 scientific payloads to achieve these scientific objectives. This paper mainly introduces the scientific objectives, exploration task, and scientific payloads.      

控制力矩陀螺驱动空间机器人的角动量平衡控制

针对V构型控制力矩陀螺(CMGs)驱动的冗余空间机器人的CMGs角动量饱和问题,提出一种角动量平衡控制方法。该方法从平衡使用机械臂各臂杆CMGs角动量的思想出发,定义了角动量平衡指标,并使用加速度分解技术和逆动力学方法设计了角动量平衡控制器。该控制器可在保证机械臂跟踪工作空间轨迹的同时,利用机械臂的空转运动使得角动量平衡指标尽量减小,即各臂CMGs的角动量使用趋于平均,从而降低某些臂杆的CMGs先行饱和的可能性,充分利用CMGs的控制能力。基于平面三自由度冗余机械臂的数值仿真结果验证了所设计的控制器的有效性。     

月面巡视探测器任务规划顶层设计与实现

针对巡视器月面任务规划工程的可实现性,开展了巡视器任务规划顶层设计方法的研究,主要内容包括:任务规划技术特点的梳理与归纳;任务规划输入条件与约束条件的整理,规划变量的统一;任务规划框架的设计,巡视器行为序列与上行控制指令的衔接,针对巡视器行为序列的大模式套用小模式的动态设计等。通过巡视器任务规划工程实现的介绍,说明在巡视器任务规划的顶层设计中,任务的不确定性、部分约束与输入信息的模糊性,是任务规划框架设计以及在后续工程实现过程中需要重点考虑的内容,是与任务规划的工程可实现性直接相关的。