多自由度的

In this paper, the overall design scheme of one assault rifle prototype with double cyclic systems and variable firing rate is illuminated in brief and the related analytical models of one DOF and two DOF by the basic theory of dynamics of multi-rigid-body system is established. The calculating analogue program in VB computer language for analyzing the movement regularities of floating body of the assault rifle prototype with some universal property and function of man-machine conversation is completed. The comparison between the calculating results and the experimental results is conducted also.

本文对某步枪双循环变射频发射原理样机方案进行了简单的说明，应用多刚体系统动力学基本理论建立了原理样枪的一自由度和二自由度动力学分析模型，用VB编写了具有一定通用性和人机对话功能的自动机运动规律分析计算程序，并将计算结果与试验结果进行了比较，验证了数理模型的正确性。

Based on ABB s IRB140 mini industrial robot,this paper analyzed a 6 DOF multi-joint industrial robot in kinematics,established its kinematics model,proposed a specific simulation algorithm for robot work spaces describing,and generated a continuous work space map,which have significant referenced value in robot kinematics,barrier avoidance,computer control and robotics education.

文章以瑞典ABB公司生产的IRB140型小型工业机器人为例，对空间六自由度多关节机器人进行了运动学分析，建立了该类型机器人的运动学模型，提出了空间六自由度多关节机器人连续工作容积的仿真算法，并根据此算法生成了该机器人的连续工作容积图，这对机器人动力学、机器人避障、微机控制和机器人教学等方面的研究有重要的参考价值。

The model is usually an inhomogeneous system of linear equations. It is pointed out that the general solution of the homogeneous system of linear equations can satisfy the request of making the wires tight, and the special solution of the inhomogeneous system of linear equations are not smaller than zero, so their sum is greater than a given mumble.

由于多自由度绳牵引并联机构的静力学模型一般是一个非齐次线性方程组，本文指出可让对应齐次方程组的通解的最小值满足绳保持张紧的条件；让非齐次线性方程组的特解非负，而避免利用对应齐次线性方程组的通解保证非齐次线性方程组的解不小于给定的最小值。

Because of mechanism parameters unknown and complicated mathematical calculations,it is very difficult for us to identify screw system independence. However,Klein projective geometry theory is used to discuss screw system dependence in this paper. As a result,it is very easy for us to identify screw system dependence by Klein projective geometry theory,so the problem of discriminating input selecting reasonability is solved.

将Klein映射理论应用到多自由度输入选取的判别中，讨论了3力3偶螺旋系的相关性，给出了相关性的判据，使相关性判别变得非常简单，避免了输入选取判别中复杂的数学运算和机构参数未知的问题，从而解决了输入选取的判别难题。

The basic idea was to discrete the structure and find the load function according to the energy criterion of buckling and the principle of random displacement method. As the critical load is the minimum of the load function, a problem of frame buckling can be transformed into an optimization problem. Therefore, the critical load can be found through solving the optimization problem.

先将结构离散为一个有限自由度系统；然后根据有限自由度系统平衡稳定性的能量准则和随机位移法的基本原理，建立符合能量准则的载荷函数，该函数不为零的最小值即为临界载荷，由此将稳定问题转化为无约束的多维优化问题；最后应用遗传算法求出相应于最优解的目标函数值。

The fluid film bearing-flexible rotor nonlinear system with squeeze film damper is modeled practically using the finite element method and the Hamilton principle.(3) The film forces produced by fluid film bearing and squeeze film damper are determined by finite element method at any moment, and the Jacobian matrix is also determined.(4) A method for analyzing the dynamics of a large system with local nonlinearities is presented. The stability and bifurcation of the equilibrium position and the unbalance responce of a fluid film bearing-flexible rotor system with squeeze film damper are investigated based on the assumption of an incompressible lubricant together with the long bearing approximation for fluid film bearing, short bearing approximation for squeeze film damper and the"π"film cavitation model.

主要研究内容包括下面几个方面：（1）对挤压油膜阻尼器-滑动轴承-转子非线性动力系统中的非线性现象进行了机理方面的研究；（2）应用有限元方法及Hamilton原理对复杂的挤压油膜阻尼器-滑动轴承-转子非线性动力系统进行了建模分析；（3）对滑动轴承及挤压油膜阻尼器中任一时刻的油膜力及相应的Ja-cobi矩阵的确定进行了分析；（4）对一类具有局部非线性的多自由度动力系统，提出了一种可以有效地分析其动力特性的方法；（5）采用实验与理论分析相结合的方法，对挤压油膜阻尼器-滑动轴承-转子非线性动力系统的动力特性进行了分析。

Both motor car and each trailer of HST were modeled as a multi-rigid-body system with two suspensions, and LVT was modeled as an assembly of track segment elements with 24 degrees of freedom. The vertical vibration matrix equation of the system was established on the basis of the principle of the total potential energy with stationary value in elastic system dynamics and the rule of "set-in-right-position" for formulating system matrixes, and then Wilson-θ numerical integration method was used to solve the problem. The dynamic responses of the system were calculated when the train runs at the speed of 200 km/h. And the effects of vertical stiffness of rail fastener and block pad on vertical vibration responses of the system were investigated.

其原理是：将高速列车的动车和拖车模拟为具有二系悬挂的多刚体系统；将弹性支承块式无碴轨道模拟为具有24个自由度的轨段单元的集合；基于弹性系统动力学总势能不变值原理及形成系统矩阵的"对号入座"法则，建立此系统竖向振动矩阵方程，并采用Wilson-θ数值积分法求解，计算速度为200 km/h时此系统竖向动力响应，研究轨道刚度对此系统竖向振动响应的影响规律。

These passive joints have more translational and rotational degree of freedom in most cases.

这些被动的关节在大多数情况下都具有更多滑移自由度和转动自由度。

Based on the torsion joint, 3-DOF finger and 5-DOF finger, a flexible pneumatic dexterous multi-fingered hand is proposed. This hand simulates the hand of human beings in structure and functions. The characteristics of this hand are summarized. The designing feasibility of this kind of hand is analyzed and the research directions are discussed.

在气动柔性扭转关节，三自由度手指和五自由度手指的基础上，提出了模拟人手结构和功能的气动柔性多指灵巧手，总结了气动柔性多指灵巧手的特点，并分析了多指灵巧手设计的可行性及研究思路。

With the rigid-body systematical kinetics theory, the 2-D and 3-D kinetics models and the kinetics parameters of the weapon are built up.

应用多刚体系统动力学基本理论建立了该武器的二自由度和三自由度动力学模型和动力学参数优化模型。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。