几何非线性分析的二维共旋铁摩辛柯梁单元

改进了独立于单元的共旋(EICR)二维梁列式,使得不必再重新推导局部共旋标架下的单元材料刚阵,该列式可直接将现有性能良好的线性梁单元扩展用于二维梁结构任意大转动的几何非线性分析,同时推导了随动压强载荷作用引起的载荷刚度项,确保了高效的收敛速率。基于二维EICR梁列式将一种工程中实用的铁摩辛柯梁单元扩展用于几何非线性分析,数值算例表明文中所提共旋列式的铁摩辛柯梁单元计算精度高、计算效率高,可用于二维梁结构的几何非线性优化。     

凸轮轮廓整数向径角的计算

以LT型剑杆织机的开口凸轮为例 ,在凸轮轮廓曲线极坐标方程基础上 ,利用解一元非线性方程———区间二分法 ,对凸轮轮廓整数向径角的计算进行了研究和讨论     

Finite-time tracking control for multiple non-holonomic mobile robots based on visual servoing

This paper investigates finite-time tracking control problem of multiple non-holonomic mobile robots via visual servoing. It is assumed that the pinhole camera is fixed to the ceiling, and camera parameters are unknown. The desired reference trajectory is represented by a virtual leader whose states are available to only a subset of the followers, and the followers have only interaction. First, the camera-objective visual kinematic model is introduced by utilising the pinhole camera model for each mobile robot. Second, a unified tracking error system between camera-objective visual servoing model and desired reference trajectory is introduced. Third, based on the neighbour rule and by using finite-time control method, continuous distributed cooperative finite-time tracking control laws are designed for each mobile robot with unknown camera parameters, where the communication topology among the multiple mobile robots is assumed to be a directed graph. Rigorous proof shows that the group of mobile robots converges to the desired reference trajectory in finite time. Simulation example illustrates the effectiveness of our method.     

基于反求技术的摆动从动件空间凸轮CAD

由于测绘点的实际接触点在理论上存在差异,摆动从动件空间凸轮机构的反求问题目前仍未获取很好解决,本文在空间凸轮反求ＣＡＤ中,担子 利用廓面测绘数据根据共轭面面原理反求出从动件运动规律,再利用该运动规律和有关结构参数重新解析设计出廓面的新方法。文中对反求方法和测绘数据进行了分析;提出了理论廓面、实际廓面的相关性质;在此基础上,利用共轭曲面原理导出了从动件运动反求的非线性规划数学模型,给出了算法。本文的     

The generalized discrete ‐centroid problem

The ‐centroid problem or leader–follower problem is generalized considering different customer choice rules where a customer may use facilities belonging to different firms, if the difference in travel distance (or time) is small enough. Assuming essential goods, some particular customer choice rules are analyzed. Linear programming formulations for the generalized ‐medianoid and ‐centroid problems are presented and an exact solution approach is applied. Some computational examples are included.     

凸轮摆动从动杆滚子的运动

本文研究凸轮机构中的摆动滚子从动件，并推导出滚子的角速度和角加速度的通用计算公式，还以不打滑为条件导出滚子转动惯量的限制公式，为滚动轴承的设计提供了运动参数计算的依据。     

用解析法确定摆杆盘形凸轮机构基本尺寸的研究

本文深入研究了摆杆的初位角ψ０对最大压力角αｍａｘ的影响。在全面考虑压力角α的极大值和最大值关系的基础上，找到压力角αｍａｘ随初位角ψ０和中心距ａ变动的曲线，从而找到了一种按最大压力角最小来确定摆杆的初位角，并进一步确定其它基本尺寸的方法。     

摆动从动件凸轮机构基本尺寸确定的CAD动画方法

通过对摆动从动件凸轮机构压力角求解过程的分析，论述了按照许用压力角设计摆动从动件凸轮机构基本尺寸的CAD动画方法，进一步介绍了用该方法确定基本尺寸的CAD过程，它可以得到精确的结果。     

Decentralised regulation of nonlinear multi-agent systems with directed network topologies

This paper aims to address the leader–follower regulation problem of multi-agent systems with directed network topologies, where the agents are described by feedforward nonlinearities with the growth rate being unknown a priori. Both the state feedback regulation protocol and the output feedback regulation protocol are delicately constructed such that all the states of followers can converge to the leader state globally. In this paper, a model transformation is firstly performed and the leader–follower regulation problem can be transformed into a general regulation problem. Then, by introducing an appropriate state transformation, the regulation problem can be changed into a parameter determined problem. It is proved that the parameter can be determined by both the properties of M-matrices and the estimates of nonlinear terms. Finally, a numerical example is presented to show the feasibility of designed protocols.     

Distributed control of LPV systems over arbitrary graphs with communication latency

This paper focuses on spatially distributed control systems where the controller sensing and actuation topology is inherited from that of the plant. Specifically, this paper considers distributed systems composed of discrete‐time linear parameter‐varying subsystems interconnected over general graph structures. These distributed systems are subject to a communication latency of one sampling period, where the information sent by a subsystem at the current time step is received by the target subsystem at the next time step. Analysis and synthesis conditions are derived for control design in this setting using a parameter‐dependent Lyapunov approach with the ?₂‐induced norm as the performance measure. Fast and easy‐to‐implement algorithms are also provided for constructing the controller in real time. The techniques developed are finally applied to a leader‐follower formation problem with intermittent communications.