航天型号PCB数字化设计与管理

提出了采用PDM系统为主体框架,以流程化设计为主线,过程管理控制为核心,实施基于PDM系统平台的PCB研制工作,并实际应用于航天型号PCB设计中。通过实施PDM系统及PCB流程化设计,实现了航天型号PCB的数字化设计与管理。     

Optimal Control Strategy for Buck Converter Under Successive Load Current Change

A new control algorithm is presented for digitally controlled dc-dc converters to achieve a fast response under a successive load-change. Under the steady-state condition, the tight voltage regulation is processed by the conventional digital PID compensator. If the load disturbance is significant, the controller switches to an optimal control scheme. With the integration of the capacitor current, the proposed algorithm predicts the optimal switch over time based on the charge balance control, and the minimal voltage derivation and recovery time are thus achieved when the load current has a successive load-change. The method for calculating the optimal switch over time is described, and the implementation of the proposed algorithm with a digital controller is treated in detail. Furthermore, the simulation and experiment results are provided to validate the effectiveness of the approaches.     

Optimal trajectory planning of free-floating space manipulator using differential evolution algorithm

The existence of the path dependent dynamic singularities limits the volume of available workspace of free-floating space robot and induces enormous joint velocities when such singularities are met. In order to overcome this demerit, this paper presents an optimal joint trajectory planning method using forward kinematics equations of free-floating space robot, while joint motion laws are delineated with application of the concept of reaction null-space. Bézier curve, in conjunction with the null-space column vectors, are applied to describe the joint trajectories. Considering the forward kinematics equations of the free-floating space robot, the trajectory planning issue is consequently transferred to an optimization issue while the control points to construct the Bézier curve are the design variables. A constrained differential evolution (DE) scheme with premature handling strategy is implemented to find the optimal solution of the design variables while specific objectives and imposed constraints are satisfied. Differ from traditional methods, we synthesize null-space and specialized curve to provide a novel viewpoint for trajectory planning of free-floating space robot. Simulation results are presented for trajectory planning of 7 degree-of-freedom (DOF) kinematically redundant manipulator mounted on a free-floating spacecraft and demonstrate the feasibility and effectiveness of the proposed method.     

水/金属燃料发动机水滴蒸发非傅里叶效应研究

水／金属燃料发动机单液滴蒸发拟选用表面模型假设,为了验证此假设的正确性,采用了修正的傅立叶定律,并分析了其物理意义及适用范围。通过试验验证及分析计算,从理论上证明,表面模型假设适用于水／金属燃料发动机水滴内部的输运过程。     

基于双因素激励理论的高校图书馆志愿者管理机制研究

图书馆志愿者的招募、培训、考评是目前图书馆志愿者的主要管理内容。通过对现有高校图书馆志愿者管理的研究,分析其存在的不足,构建出一种新的基于双因素激励理论的图书馆志愿者管理机制,以期能更好地为用户服务。     

澳门文化遗产旅游发展因素研究——基于品质屋的视角

近年来,澳门特区政府加大文化遗产旅游发展力度,取得了良好成效,历史城区的众多文化遗产景点游客数量激增,但仍存在一些亟待改进的地方.为解决这些问题,首先通过“平衡记分卡”对澳门文化遗产旅游的发展因素进行梳理,然后进行SWOT分析,通过各因素的匹配找到七条战略举措.为验证这些战略举措是否与发展因素相适配,采用“质量功能展开”的品质双屋矩阵图验证所获得的战略举措与发展因素之间存在因果关系,同时通过数值的大小标明各环节的工作重要程度,再通过品质屋对战略举措进行简化和具体化,以促进澳门文化遗产旅游能够实现持续发展,成为世界旅游休闲中心.     

基于同步控制的行李电机ACA-RBF-PID控制

针对机场行李准确地从传送带导入分拣机的问题,提出将基于同步控制的ACA-RBF-PID算法应用于机场行李导入电机。该方法利用蚁群算法优化RBF神经网络避免了传统RBF网络方法带来的局部优化问题,实现了全局最优,并且电机同步控制系统保证了从导入电机与导入电机速度始终保持一致,避免了同时将两件行李送上同一个行李托盘。仿真结果表明,该策略大大地提高了行李导入效率,为行李的后续分拣带来保证。     

弹道导弹中段机动突防制导误差修正方法

针对弹道导弹中段反拦截实时机动突防带来的参数偏差问题,给出了在地球非球形摄动影响下的位置和速度偏差量的计算方法,采用改进的fg级数和预测制导方法获得了机动推力的作用方向及发动机的开启时间,并对再入点误差进行了修正。仿真结果表明,采用该方法可有效地修正因机动突防与地球扁率而引起的再入点参数误差,为末制导系统的工作提供了良...     

弧线齿面齿轮齿面接触分析

为了提高面齿轮副的强度并解决其磨齿问题,提出了弧线齿面齿轮副的一种新的加工方法,并研究其啮合特性.用有刀倾的刀盘旋转而成的切削面作为假想齿轮的齿面,模拟产形齿轮和被加工齿轮啮合过程.推导弧线齿面齿轮副齿面方程;根据两齿面在啮合过程中连续相切条件.建立了考虑安装误差的轮齿接触分析(TCA)模型;齿轮副计算机啮合仿真结果表...