Maneuverability modeling and trajectory tracking for fish robot

This study develops a 6-DOF mathematical model for a robotic fish that considers surge, sway, heave, roll, pitch, and yaw. The model considers the conditions of a fish swimming in ocean current perturbations similar to the ocean current perturbations of the slender-body autonomous underwater vehicles. For swimming and turning behaviors, a nonlinear, dynamic, carangiform locomotion model is derived by using a planar four-link model. A 2-DOF barycenter mechanism is proposed to provide body stabilization and to serve as an actuating device for active control design. A barycenter control scheme is developed to change the center of gravity of the robot fish body by moving balancing masses along two axes. The projected torque on x and y axes propel pitch and roll angles to the desired settings. A Stabilizing controller, fish-tail mechanism, rigid body dynamics, and kinematics are incorporated to enable the fish robot to move in three dimensional space. Simulation results have demonstrated maneuverability and control system performance of the developed controller which is proposed to conduct path tracking of the robot fish as it swims under current perturbations.     

基于可操作度的虚拟人手部避障运动控制算法

研究复杂作业环境中虚拟人手部避障运动的高精度控制问题,问题的关键是解决虚拟人手的设计.为了灵活操作能在操作的末端临时变换姿态,给控制过程中手臂转动路线,速度,加速度等参数的控制带来较大困难.传统的控制方法通过增加控制自由度来解决这个问题,但是一旦自由度增加,会带来冗余控制影响,弊端较为明显.提出一种采用可操作度矩阵的逆向运动学控制算法,引入可操作度模型进行肢体末端效应器运动路径的生成,与HAL链IK分析求解方法相结合,实现了真实感较强的肢体实时运动控制.通过仿真和动作捕获实验验证了算法的有效性,可应用于人机工程仿真中的避障控制和干涉检查.     

坦克机动性虚拟试验研究

主要研究了虚拟环境中军用车辆特别是坦克机动性虚拟试验时动力学模型的建立，建立了虚拟环境下坦克的实时动力学模型，并且描述了整个虚拟试验视景仿真系统的组成及其实现过程。     

Evaluation of the dynamic performance variation of a serial manipulator after eliminating the self-weight influence

Manipulators used in the industrial field usually have a very stiff structure but without an equivalent payload on their end-effectors. This is because the stiff structure is used to prevent excessive deformation which will negatively impact the positioning accuracy of the manipulator, especially when the manipulator is fully extended. However, the stiff structure increases the weight of the manipulator and consumes much of the output of the constituent joint actuators in order to overcome the gravitational force resulting from the heavy structure. To cope with this problem, the concept of gravity balance was proposed decades ago, and there have been several approaches suggested to eliminate the influence of the self-weight of the structure. With the help of gravity balance, the output of the constituent joint actuators can fully be used to drive the manipulator and save considerable energy when the manipulator is in static or low-speed applications.For decades, many papers have discussed how to make a manipulator in gravity balance or how to design and apply a gravity balance mechanism to satisfy a certain application. However, none of them discuss what the influence on the dynamic performance of a manipulator is after it is equipped with a gravity balance mechanism or how to evaluate that influence. To rectify this insufficiency, this article utilizes acceleration radius to be the index of measuring the dynamic performance before and after a manipulator is equipped with a gravity balance mechanism and proposes a new index, the maneuverability ratio, to provide quantitative information to measure whether the dynamic performance of the manipulator increases or not after the gravity balance mechanism is applied.     

Optimum tire contour design using systematic stom and neural network

An efficient multi-objective optimization method is presented making use of neural network and a systematic satisficing trade-off method (STOM), in order to simultaneously improve both maneuverability and durability of tire. Objective functions are defined as follows: the sidewall-carcass tension distribution for the former performance while the belt-edge strain energy density for the latter. A back-propagation neural network model approximates the objective functions to reduce the total CPU time required for the sensitivity analysis using finite difference scheme. The satisficing trade-off process between the objective functions showing the remarkably conflicting trends each other is systematically carried out according to our aspiration-level adjustment procedure. The optimization procedure presented is illustrated through the optimum design simulation of a representative automobile tire. The assessment of its numerical merit as well as the optimization results is also presented.     

改变即日常——阿科米星的实践综述

在快速城市化背景下实践的中国建筑师是否可能从纷繁复杂的日常城市和建筑中发现建筑学的新经验？这正是阿科米星最近相关实践和研究的动力。本文指出工作室对日常的关注同一贯的工作立场、出发点、思考方式和价值观念有关,是一个逐步延续和转变的过程。日常建筑中蕴含的使用调整、有效建造和时间差异感的力量被尝试转化为具体的实践策略。改变即日常,自然而恒久。在中国社会不确定的语境中探索建筑学还能做什么意味着开放的边界和更多的可能。     

论提高焦炉系数的可操作性

用调查分析、现场测试等方法,找出影响焦炉K<,炉头>系数的主要原因,然后有针对性的实施行之有效的对策,解决问题.保证焦炉严密性,稳定焦炭质量.     

基于CFD的两栖车辆水动力导数的计算方法

通过采用标准k-ω模型,结合动网格技术,使用CFD(Computational Fluid Dynamics)技术模拟两栖车辆的PMM(Planar Motion Mechanism)实验,拓展了针对两栖车辆的水动力导数的数值计算方法.研究中,对比直航试验以验证计算的有效性,并分析提取数值数据,实现了水动力导数的求取.将计算所得水动力导数与船舶经验公式值对比,分析了两栖车辆与船舶的差异对水动力导数造成的影响.     

中外会计软件的制度遵循性比较

与一般计算机应用软件不同，会计核算软件处理的主要是会计核算的数据。这一处理过程是否准确可靠，关系到会计准则和会计制度的遵行。作为直接服务于财务会计子系统的应用软件，“合规性”是其突出特点。鉴于此，本文从中外会计软件的制度遵循性角度进行分析。     

Delta分拣机械手工作空间奇异性及可操作度分析

针对智能分拣机械手可达空间内可操作度问题,以三自由度Delta平移并联分拣机械手为研究对象。在对它进行运动学研究的基础上,提出一种新的工作空间整体求解数值方法,并分析主、从动臂长度和工作台半径对工作空间的影响。通过Jacobian矩阵对Delta分拣机械手奇异位形和可操作度进行探讨。为了改善分拣机械手结构尺寸,提出一种基于正解条件数的优化方法。