A Dynamic Model of an Underwater Quadruped Walking Robot Using Kane's Method

In this paper, the kinematics and dynamics of an underwater quadruped walking robot were derived based on Kane dynamic equations. This methodology allows construction of the dynamic model simply and incrementally. The velocity and angular velocity components of an underwater quadruped walking robot were served as the generalized velocities. The forces which contribute to dynamics of an underwater quadruped walking robot were determined by Kane's approach. The equations of hydrodynamic forces of an underwater quadruped walking robot were deduced. Hydrodynamic coefficients were determined by experiments. The dynamic model was established by obtaining the generalized active forces and the generalized inertia forces. Numerical simulations of the walking behavior on underwater flat ground were implemented to verify the dynamic model of an underwater quadruped walking robot. Simulation results show that the dynamic model is correct.

Simulation Platform for the Underwater Snake-Like Robot Swimming Based on Kane's Dynamic Model and Central Pattern Generator

A systematic method for swimming control of the underwater snake-like robot is still lacking. We construct a simulation platform of the underwater snake-like robot swimming based on Kane's dynamic model and central pattern generator(CPG). The partial velocity is deduced. The forces which contribute to dynamics are determined by Kane's approach. Hydrodynamic coefficients are determined by experiments. Then, we design a CPG-based control architecture implemented as the system of coupled nonlinear oscillators. The CPG, like its biological counterpart, can produce coordinated patterns of rhythmic activity while being modulated by simple control parameters. The relations between the CPG parameters and the speed of the underwater snake-like robot swimming are investigated. Swimming in a straight line, turning, and switching between swimming modes are implemented in our simulation platform to prove the feasibility of the proposed simulation platform. The results show that the simulation platform can imitate different swimming modes of the underwater snake-like robot.

Modeling of a space flexible probe–cone docking system based on the Kane method

Recent developments in micro- and nano-satellites have attracted the interest of the research community worldwide. Many colleges and corporations have launched their satellites in space. Meanwhile, the space flexible probe-cone docking system for micro- and nano-satellites has become an attractive topic. In this paper, a dynamic model of a space flexible probe-cone dock- ing system, in which the flexible beam technology is applied, is built based on the Kane method. The curves of impact force versus time are obtained by the Lagrange model, the Kane model, and the experimental method. The Lagrange model was presented in the reference and verified by both finite element simulation and experiment. The results of the three methods show good agreements on the condition that the beam flexibility and the initial relative velocity change. It is worth mentioning that the introduction of vectorial mechanics and analytical mechanics in the Kane method leads to a large reduction of differential operations and makes the modeling process much easier than that of the Lagrange method. Moreover, the influences of the beam flexibility and the initial relative velocity are discussed. It is concluded that the initial relative velocity of space docking operation should be controlled to a certain value in order to protect the docking system.

基于Kane方法的机器海豚动力学建模及速度优化方法

在利用Kane方法对机器海豚进行动力学建模的基础上,提出了一种对豚体波拟合推进进行速度优化的方法.首先,选取各连杆的关节角和机器海豚头部质心的坐标作为广义坐标,对具有三个推进关节的机器海豚进行运动学分析,进而得到广义惯性力;然后,结合对各连杆受力分析得到的广义主动力,建立机器海豚的动力学方程.其中,根据尾鳍攻角所处的不同范围,分别利用升力线理论和阻力模型将尾鳍建模为有限翼展机翼或平板来计算水动力.在此基础上,结合豚体波拟合推进,提出一种通过调节尾鳍关节角规律的幅度和相位来优化平均推进速度的方法.仿真结果表明了所建模型及优化方法的有效性.

基于Kane方法的仿鱼机器人波状游动的动力学建模

提出了基于Kane方法的仿鱼机器人波状游动的动力学模型。通过对鱼体波状游动的运动学描述,将仿鱼机器人离散成刚性头部、柔性身体和摆动尾鳍三个部分并划分为多个运动环节进行分析,考虑鱼体外部环境的作用力:流体附加质量、流体加速作用的弗劳德—克里洛夫力、鱼体游动过程中的阻力特征,建立仿鱼机器人的动力学模型。数值实例表明,利用该动力学模型,能够有效地实现给定鱼体各环节的运动参数求解作用力矩、给定作用力矩求解运动规律,进一步设计仿鱼机器人各环节的运动规律,寻找一种实现鱼体推进力最大和推进效率最高的规划方法。该动力学模型的建立为研究仿鱼机器人的运动控制算法和规划算法,揭示鱼体利用流场能量的动力学机理提供了重要理论支撑。

机器人手臂弹性动力学分析的Kane方法

本文将 Kane 动力学方法与假设模态法相结合.给出一种分析机器人手臂弹性动力学的新方法.首先基于 Kane 方法的运动学概念,并应用假设模态法建立了手臂弹性运动学.推导出完整的弹性动力学方程.并以一简例说明了其应用过程.这种方法比较简洁,兼具 Lagrange 法和 Newton-Euler 法的优点而克服了其不足,便于计算机数值分析.

基于Kane方法的双臂空间机器人动力学分析

机器人的动力学分析作为机器人设计和控制的中间桥梁,其独特的动力学特性和控制特征非常重要。本文系统研究了双臂空间机器人系统的拓扑结构、运动学及动力学特征,并基于Kane-Huston方法和旋量理论建立了双臂空间机器人系统动力学模型。算例表明,对于给定的运动参数,采用所建立的模型,可以求出双臂空间机器人各组成部分的瞬时运动,反之亦然。仿真结果表明,本文中基于旋量理论的Kane-Huston方法建立的双臂空间机器人系统动力学模型是符合实际的。

Algebraic Method‑Based Point‑to‑Point Trajectory Planning of an Under‑Constrained Cable‑Suspended Parallel Robot with Variable Angle and Height Cable Mast

To avoid impacts and vibrations during the processes of acceleration and deceleration while possessing flexible working ways for cable-suspended parallel robots(CSPRs),point-to-point trajectory planning demands an under-constrained cable-suspended parallel robot(UCPR)with variable angle and height cable mast as described in this paper.The end-effector of the UCPR with three cables can achieve three translational degrees of freedom(DOFs).The inverse kinematic and dynamic modeling of the UCPR considering the angle and height of cable mast are completed.The motion trajectory of the end-effector comprising six segments is given.The connection points of the trajectory segments(except for point P3 in the X direction)are devised to have zero instantaneous velocities,which ensure that the acceleration has continuity and the planned acceleration curve achieves smooth transition.The trajectory is respectively planned using three algebraic methods,including fifth degree polynomial,cycloid trajectory,and double-S velocity curve.The results indicate that the trajectory planned by fifth degree polynomial method is much closer to the given trajectory of the end-effector.Numerical simulation and experiments are accomplished for the given trajectory based on fifth degree polynomial planning.At the points where the velocity suddenly changes,the length and tension variation curves of the planned and unplanned three cables are compared and analyzed.The OptiTrack motion capture system is adopted to track the end-effector of the UCPR during the experiment.The effectiveness and feasibility of fifth degree polynomial planning are validated.

水下自重构机器人Kane动力学建模方法

针对水下自重构机器人构形多变且外部环境复杂等特点,提出了一种通用的、基于构形描述及Kane动力学的建模方法.利用图论中关于拓扑结构的描述方法,建立水下自重构机器人多种拓扑构形的统一数学表达,再结合Kane方法,在模型中加入水下各种外部环境作用力,最终建立封闭的水下自重构机器人运动方程.通过典型构形的建模实例,证明了该方法的可应用性和有效性.

人体步态分析的Kane动力学模型

对Hanavan15刚体人体模型进行简化。建立由6个刚体组成的6自由度Kane动力学模型,由此获得人体参数和肌肉参数。再利用6自由度Kane方程及约束条件,计算出人体在步态运动情况和脚部突然受阻静止后引起的人体运动情况,得到各杆的初始转速。从而模拟出人体运动情况及人体着地时与地面的撞击力。

闭链级混联式液压机械臂运动控制方法

针对含有多个闭链结构的液压机械臂非线性强、控制精度低等特点,采用了虚拟分解控制方法消除了系统非线性引入的误差,以提高其控制精度。首先,根据驱动方式不同将整个机械臂分解为四类结构,针对每一类结构再将其虚拟分割成每一子系统,对每个子系统分别建立了刚体动力学模型、液压执行器流体动力学模型;然后,基于刚体动力学模型和流体动力学模型分别设计了刚性连杆控制律和液压执行器控制律,其前馈控制量和误差反馈量是高精度控制的基础;最后,使用Simulink的Simscape模块建立了该机械臂的多物理域混合模型,进行了轨迹跟踪效果验证,同时引入了控制性能指标,在不同机械臂的液压执行器空间进行了计算。研究结果表明:相比于比例-积分-微分控制器,基于虚拟分解控制理论搭建的控制器控制精度提升较大,单关节平均绝对误差最大降低了88.9%,且控制效果与其他较先进液压控制器的性能指标相近。针对含复杂闭链结构的混联式液压机械臂,采用虚拟分解控制理论能有效提升控制精度。

基于Kane方法的小型无人直升机的动力学分析

针对具有高度非线性、复杂动力学特性的小型无人直升机,基于Kane方法,提出了一种推导其动力学模型的新方法。该方法兼有矢量力学和分析力学的优点,首先采用欧拉角为绕机体坐标轴3-2-1重新建立了小型无人直升机的平移和旋转动力学模型,建模过程中考虑到主旋翼陀螺效应对模型的影响,将主旋翼当成刚体,减小了建模的复杂度。其次,通过优化模型使纵横向通道实现解耦,便于姿态控制器的设计。最后,仿真实验展现了小型无人直升机的平移和旋转运动规律,并通过实飞实验反映了小型无人直升机在悬停状态下的动态特性,将实飞实验数据和优化后的仿真结果进行比较,证明了所建模型的有效性。

上肢康复机械臂运动学和力学模型建立与分析

针对传统康复机械臂存在的适配人体上肢自由度低、便携性较差、左右肢体互换困难等问题,提出一种9自由度的便携型上肢康复机械臂,满足偏瘫患者的训练需求。运用Matlab建立DH坐标系和运动学模型,通过蒙特卡洛法获取康复机械臂的三维空间点云图,验证其工作空间的合理性。基于牛顿-欧拉和拉格朗日方程对上肢康复机械臂进行动力学建模,推导了上肢康复机械臂力矩计算公式。将Adams动力学仿真与理论公式计算获取的各关节力矩值进行对比分析,计算两者之间的误差。实验结果表明,理论力学公式计算结果与Adams仿真结果误差值在0.1 N∙m以内,各关节的误差均在5%以内。实验结果验证了理论力学公式的正确性,为后续控制系统的建立和实物样机的制作提供了可靠的理论依据。

基于非线性摩擦力模型和WLS-CS算法的机器人动力学参数辨识

为了实现对工业机器人的高精度控制,需要一个高精度的动力学模型,因此要对动力学参数进行精准辨识。提出一种基于非线性摩擦力模型和加权最小二乘法与布谷鸟算法(WLS-CS)结合的动力学参数辨识方法。首先通过Newton-Euler法进行机器人的动力学建模,结合非线性摩擦力模型,完成机器人全动力学模型的建模。设计5阶有限项傅里叶级数作为激励轨迹,并优化激励轨迹参数。使用加权最小二乘法对动力学参数进行初步辨识。辨识结果作为布谷鸟算法的初始解范围,结合Levy飞行与巢穴的优胜劣汰机制,寻找到动力学参数辨识的全局最优解。更换轨迹对机器人全动力学模型进行验证,计算机器人的仿真力矩,并与实验力矩反馈值进行对比。结果表明上述方法辨识的动力学参数辨识精度的残差方根(RMS)值下降8.6%,可以建立精确度较高的动力学模型。

基于Kane动力学和通路矩阵的水下自重构机器人建模

文章推导出基于通路矩阵和Kane方法的水下自重构机器人的运动学和动力学方程。引入图论的知识解决水下自重构机器人的统一构形描述问题,提出采用通路矩阵描述水下自重构机器人的不同构形,结合Kane方法,建立了水下自重构机器人的运动学和动力学模型。以水下自重构机器人的典型构形(水下四足行走构形)为例,验证了该方法的有效性和可用性。

Dynamic Model of Underwater Snake-Like Robot Using Kane's Method

In this paper, a dynamic model for an underwater snake-like robot is developed based on Kane's dynamic equations. This methodology allows construction of the dynamic model simply and incrementally. The partial velocity is deduced. The forces which contribute to dynamics are determined by Kane's approach. The generalized active forces and the generalized inertia forces are deduced. The model developed in this paper includes inertia force, inertia moment, gravity, control torques, and three major hydrodynamic forces: added mass, profile drag and buoyancy. The equations of hydrodynamic forces are deduced. Kane's method provides a direct approach for incorporating external environmental forces into the model. The dynamic model developed in this paper is obtained in a closed form which is well suited for control purposes. It is also computationally efficient and has physical insight into what forces really influence the system dynamics. The simulation result shows that the proposed method is feasible.

CONTROLLING ROBOT MANIPULATORS BY DYNAMIC PROGRAMMING

A certain number of considerations should be taken into account in the dynamic control of robot manipulators as highly complex non-linear systems.In this article,we provide a detailed presentation of the mechanical and electrical impli- cations of robots equipped with DC motor actuators.This model takes into account all non-linear aspects of the system.Then,we develop computational algorithms for optimal control based on dynamic programming.The robot's trajectory must be predefined,but performance criteria and constraints applying to the system are not limited and we may adapt them freely to the robot and the task being studied.As an example,a manipulator arm with 3 degrees of freedom is analyzed.

基于kane方法的关节机器人举升机构的动力学分析

以应用于平板玻璃基板搬运领域的关节机器人的举升机构为研究对象,针对举升机构由串联的两个平行四连杆机构组成以及各组成构件间存在着复杂的动力学非线性耦合关系的特点,采用kane方法建立了该机构的递推动力学方程,基于动力学方程对举升机构的动力学特性进行了仿真分析,分析的结果表明延长驱动关节的加速时间是提高举升机构运行平稳性的可行方法,从而为机器人举升机构的优化设计和平稳控制提供了理论依据。

Dynamic Study on Rigid and Flexible Coupling System for Terminally Sensitive Submunition

A kinetic model of the rigid and flexible coupling system for terminally sensitive submunition is set up with Kane's method. The parachute is considered as a flexible body, the flexible displacement is expressed with modal spread method, the position of the parachute is expressed with a hybrid coordinate method, and the kinematics of the terminally sensitive submunition is analyzed. Ten generalized coordinates relative to the attitude of the terminally sensitive submunition are chosen, and the correlative generalized active forces, the generalized inertial forces, the generalized internal forces are calculated in turn. On the base of the Kane's method, the ten degrees of freedom dynamic equations for the coupled terminally sensitive submunition are finally set up. This model can be used to expediently simulate and analyze accurately the exterior ballistic trajectory of terminally sensitive submunition, and provide the overall design of the terminally sensitive submunition with some helpful references.

履带式移动机器人技术研究

履带式移动机器人在非结构环境领域具有的广泛应用,提高该类机器人的高通过性和多地形适应性是目前研究的关键和前沿问题。以履带式移动机器人在多种复杂环境地形上的高通过性、高适应性为出发点,重点研究了可变形履带式移动机器人的机构实现方法、机器人与地面的交互作用机理、移动机器人运动学和动力学建模方法等问题,为履带式移动机器人的研究提供了重要的理论基础,对于提高履带式移动机器人在实际中的具体应用具有重要的作用。