The inertial characteristics of dynamic robot modelsCaracteristiques inertielles des modeles dynamiques robotiques

Robot dynamics are embedded in the mathematical foundations of classical mechanics to introduce novel physical interpretations and structural characteristics of the Lagrangian dynamic robot model. Within this framework, the centrality of the inertial matrix emerges. The physical significance of the inertial coefficients is further illuminated by the introduction of the coefficient of coupling of robotic manipulators. The properties of the inertial matrix follow directly from the kinematic and dynamic parameters of the robot. These properties translate into the characteristics of the centrifugal, Coriolis and gravitational components of the dynamic robot model. The novel approach reinforces the need to integrate the mechanical and controller designs of robotic manipulators. The conceptual framework leads to design guidelines for simplifying and reducing the nonlinear kinematic and dynamic coupling of robot dynamics. The development of the paper is applied to illustrate the properties and structural characteristics of industrial robots.     

基于切断点自由度解耦的手腕偏置型6R机器人位置反解

手腕偏置型6R机器人的位置反解没有封闭解.将机器人的偏置型手腕分为侧端偏置、上端偏置和前端偏置.针对手腕前端偏置型6R机器人位置反解问题,利用机器人几何结构特征,将机构运动链在关节坐标系原点或相邻坐标系轴线交点处切断为两部分,使两条子运动链在切断点处运动自由度的某个分量上的耦合度最小,从而便于导出关节变量之间的关系.将含6个未知数的高维方程组转化为仅含1个未知数的非线性方程,通过一维迭代搜索获得机器人位置反解的数值解.     

Tricept机器人的尺度综合方法研究

Tricept机器人是目前商业上最为成功的并联机器人之一。提出一种Tricept机器人中三自由度并联机构的最优尺度综合方法。该方法首先导出尺度参数间的关系,其次构造一种均衡条件数全域均值及其极差间矛盾的综合操作性能指标,进而将尺度综合问题归结为一类双参数优化问题。该方法对掌握这类及其他并联机构的运动学设计理论有一定指导意义。     

应用基于运动螺旋的机器人正解映射求解FANUC机器人的逆运动学问题

提出了应用基于运动螺旋的开链机器人正解映射 ,求解闭链机器人 - FANU C机器人逆运动学问题的方法 ,该方法为求解一般机器人的逆运动学问题提供了参考     

基于任务灵活性的脑外科机器人机构设计

为了避开脑部重要组织,降低手术造成的损伤,脑外科手术机器人需要具有良好的任务灵活性,可以辅助医生将手术针按照特定位姿精确定位到病灶点上.对比分析了两类有解析逆解的脑外科机器人构型,着重分析机器人后两个关节参数对任务灵活性影响,以此针对脑外科机器人工作现实,给出了机器人机构参数优化方法,对两类机器人进行了机构优化设计与选型.此对比分析与优化设计方法可供医疗机器人构型选择.     

一种铆接机械手的运动精度可靠性分析

介绍了一种六自由度工业机器人的运动精度可靠性分析方法。通过分析一种铆接机械手的结构,基于D-H坐标法,建立运动数学模型,并考虑加工和装配过程中尺寸误差和间隙误差的随机性,将结构参数和运动变量误差视为随机变量,建立运动误差模型,结合机构运动学和可靠性理论,构建机械手运动精度可靠性模型。通过算例,验证了该方法的可行性,为该类型工业机器人的可靠性设计和结构优化提供了一定的理论参考。     

MICRAS,Microcomputer interactive codes for robot analysis and simulationMICRAS: Logiciel interactif sur micro-ordinateur pour l'analyse et la simulation des robots

With the growth and acceptance of interactive computer graphics, contemporary robotic research trends are focusing on the development of robot simulation packages. This paper describes a new microcomputer interactive package for the analysis and simulation of industrial robots. The package represents an extension of the state-of-the-art developments in the technology of industrial robots. The novel features are derived from the use of the microcomputer for analysis and simulation. The package includes all aspects of the kinematic analysis of the six general geometric structures of industrial robots.MICRAS is a package of microcomputer interactive codes for robot analysis and simulation. The program WORKSPACE is used for obtaining the value and plot of the workspace of two- and three-link revolute-jointed arms. DIRKIN is a program that generates the forward solution for any robot with up to six degrees of freedom. The data input section provides the robot geometric parameters and joint angles interactively. The program REVKIN is constructed to give the inverse solution of the six major kinematic structures of robots and display all possible configurations for each robot. COJOINT is a program that implements coordinated joint motion of a robot with defined range of motion of each joint. The modules with prefix CAT constitute the program for the simulation of robot movements for a specified cartesian path of the end effector. Finally, DIRDIF is a program for the differential kinematic analysis of robots.     

Type Synthesis of Walking Robot Legs

Walking robots use leg structures to overcome obstacles or move on complicated terrains. Most robots of current researches are equipped with legs of simple structure. The specific design method of walking robot legs is seldom studied. Based on the generalized-function(GF) set theory, a systematic type synthesis process of designing robot legs is introduced. The specific mobility of robot legs is analyzed to obtain two main leg types as the goal of design.Number synthesis problem is decomposed into two stages, actuation and constraint synthesis by name,corresponding to the combinatorics results of linear Diophantine equations. Additional restrictions are discussed to narrow the search range to propose practical limb expressions and kinematic-pair designs. Finally, all the fifty-one leg structures of four subtypes are carried out, some of which are chosen to make up robot prototypes, demonstrating the validity of the method. This paper proposed a novel type synthesis methodology, which could be used to systematically design various practical robot legs and the derived robots.     

Review of human–robot coordination control for rehabilitation based on motor function evaluation

As a wearable and intelligent system, a lower limb exoskeleton rehabilitation robot can provide auxiliary rehabilitation training for patients with lower limb walking impairment/loss and address the existing problem of insufficient medical resources. One of the main elements of such a human–robot coupling system is a control system to ensure human–robot coordination. This review aims to summarise the development of human–robot coordination control and the associated research achievements and provide insight into the research challenges in promoting innovative design in such control systems. The patients’ functional disorders and clinical rehabilitation needs regarding lower limbs are analysed in detail, forming the basis for the human–robot coordination of lower limb rehabilitation robots. Then, human–robot coordination is discussed in terms of three aspects: modelling, perception and control. Based on the reviewed research, the demand for robotic rehabilitation, modelling for human–robot coupling systems with new structures and assessment methods with different etiologies based on multi-mode sensors are discussed in detail, suggesting development directions of human–robot coordination and providing a reference for relevant research.     

Attribute based specification, comparison and selection of a robot

The problem of robot selection has been of concern to manufacturers for many years. This problem has become more difficult in recent years due to increasing complexity, available features, and facilities offered by different robotic products. The objective of this research is to generate and maintain reliable and exhaustive database of robot manipulators based on their different pertinent attributes. This database can be used to standardize the robot selection procedure when the manufacturing firm has decided to use the robot for a particular operation. This will help the robot user to save time by providing him a tool for selecting the robot system most suited for his operational needs. The robot selection procedure allows rapid convergence from a very large number of candidate robots to a manageable shortlist of potentially suitable robots using ‘elimination search’ based on the few critical selection attributes. Subsequently, the selection procedure proceeds to rank the alternatives in the shortlist by employing different attributes based specification methods and graphical methods. The ranks of the candidate robots are calculated with respect to the best possible robot, say +ve benchmark robot, for particular application. This ranking will provide a good guidance for the robot user to select the robot. It will also provide a good insight to the robot manufacturer so that he can improve his product or introduce new product to fulfill the need of customer. It will help the designer at various design stages, while the maintenance people can plan maintenance strategy to reduce the down time and maintenance efforts. This is an attempt to create exhaustive database by identifying maximum possible number of attributes for robot manipulators. The coding scheme and the selection procedures, mathematical and graphical, are illustrated with example.     

A Cell Management System to Support Robotic Assembly

There is an increasing requirement for the assembly of wider ranges of products in relatively small lot sizes. Consequently, robots are seen as being attractive as an assembly method. There has been much work on developing advanced robot grippers and applying vision systems/artificial intelligence. There has, however, been relatively little work on the overall problem of controlling robotic assembly cells (RACs) and their integration into the wider manufacturing organisation. This paper describes the design of a cell management system (CMS) based on a standard personal computer. The CMS supports RAC operations by managing/presenting data relevant to the cell operator. It also provides an interface between the cell and other organisational computer systems. Furthermore, the CMS allows error checking and recovery functionality to be implemented within an RAC without the need for modifications to the robot controller. Finally, the paper describes a pilot cell developed to test the CMS design.     

Teleloperation of field mobile manipulator with wearable Haptic-based Multi-Modal user interface and its application to explosive ordnance disposal

This paper describes a wearable multi-modal user interface design and its implementation for a teleoperated field robot system. Recently some teleoperated field robots are employed for hazard environment applications (e.g. rescue, explosive ordnance disposal, security). To complete these missions in outdoor environment, the robot system must have appropriate functions, accuracy and reliability. However, the more functions it has, the more difficulties occur in operation of the functions. To cope up with this problem, an effective user interface should be developed. Furthermore, the user interface is needed to be wearable for portability and prompt action. This research starts at the question: how to teleoperate the complicated slave robot easily. The main challenge is to make a simple and intuitive user interface with a wearable shape and size. This research provides multi-modalities such as visual, auditory and haptic sense. It enables an operator to control every functions of a field robot more intuitively. As a result, an EOD (explosive ordnance disposal) demonstration is conducted to verify the validity of the proposed wearable multi-modal user interface.     

一种协作机器人位姿重复性优化综合

在给定位姿重复性要求的前提下,寻找各关节随机运动精度的最优分配方案能够使协作机器人设计更加合理,对降低机器人制造成本有重要意义.首先,在机器人位姿重复性分析的基础上,建立了位姿重复性数学模型,该数学模型包含机器人位置重复性和姿态重复性;其次,以协作机器人KUKA iiwa 7为例,以关节运动误差最大化为优化目标,对该机...     

机器人机构精度综合的正交试验法

采用正交试验法综合机器人机构精度,只需要较少的计算仿真工作量就可分析出机器人定位误差,甚至不需要制造出具体的机器人物理样机。该试验方法可以缩短误差综合的计算过程,简化机器人误差综合。基于此,总结国内外有关机器人和空间机构精度研究,建立典型3R机器人的误差传递模型,利用正交设计表均衡排布各参数的误差水平,对各组试验结果进行方差分析,绘制某一复杂曲面任务下机器人末端的误差分布图和影响末端误差因素的显著程度顺序图。结果表明,正交试验法能够快速计算出当前目标点下误差因素对末端误差的影响显著程度,指导机器人精度设计和运动学参数的标定。     

Design and modeling of a novel soft parallel robot driven by endoskeleton pneumatic artificial muscles

Owing to their inherent great flexibility, good compliance, excellent adaptability, and safe interactivity, soft robots have shown great application potential. The advantages of light weight, high efficiency, non-polluting characteristic, and environmental adaptability provide pneumatic soft robots an important position in the field of soft robots. In this paper, a soft robot with 10 soft modules, comprising three uniformly distributed endoskeleton pneumatic artificial muscles, was developed. The robot can achieve flexible motion in 3D space. A novel kinematic modeling method for variable-curvature soft robots based on the minimum energy method was investigated, which can accurately and efficiently analyze forward and inverse kinematics. Experiments show that the robot can be controlled to move to the desired position based on the proposed model. The prototype and modeling method can provide a new perspective for soft robot design, modeling, and control.     

基于MATLAB-Robotics工具箱的工业机器人轨迹规划及仿真研究

对Cincinnati T3-746工业机器人的运动学轨迹规划进行了分析与仿真。通过实验对该工业机器人的三关节的关节轨迹进行了三次多项式插值运算。利用MATLAB-Robotics工具箱对该工业机器人进行了建模,实现了对工作空间内任意直线、圆弧轨迹拟合插值运算。通过运动学正反解的计算,得到了实时的关节空间坐标的数值解。为该工业机器人进一步的研究和应用提供了理论分析依据。     

基于刚度定向的工业机器人铣削姿态优化研究

针对工业机器人结构非对称引起的主刚度方向难以确定、因刚度低导致的铣削过程中容易发生模态耦合颤振的问题,提出了一种机器人加工系统主刚度定向方法,并利用机器人功能冗余特性优化姿态,以提高铣削过程的稳定性。计算工业机器人末端笛卡儿坐标系中的刚度椭球,确定切削平面内机器人的主刚度方向;通过建立加工系统的动力学模型,得到机器人铣削模态耦合颤振的稳定性判据;基于刚度定向方法,提出一种机器人铣削姿态优化算法。实验结果表明,在不改变其他参数的情况下,通过优化工业机器人姿态,可以保证机器人沿给定轨迹加工的稳定性。     

Navigation-oriented design for in-pipe robot in recursively divided sampling space with rapidly exploring random tree

Gas pipelines are subject to periodic inspection and maintenance for safety and longevity. Many robotic inspection systems have been developed for in-pipe applications, but systematic geometric design methodology that is suitable for in-pipe navigation has not been well studied so far due to difficulties in predicting the capability of maneuvering through the obstacles inside of pipelines such as bend, miter, and T-branch joint. The geometric design of the robot is critical to the performance of such in-pipe robots because the actuation and the measurement are constrained by the shape and the size of the robot. In this paper, we propose a design methodology that finds the maximum value of geometric design parameters of the robot with recursive evaluation of the parameter values in the design parameter space. The role of the design space division is to reduce the search region and to increase the number of parametric samples to near optimal values. As a parameter evaluation method, we adapt Rapidly exploring random tree (RRT) because it is known to be suitable for solving narrow passage problems for high-dimensional systems. Our design method makes it possible to find an optimal parameter set without computing complex cost functions. The design result of the in-pipe robot is 8 % larger than that of a heuristic geometry-based approach in three-parameter design problem.

     

Novel Door-opening Method for Six-legged Robots Based on Only Force Sensing

Current door-opening methods are mainly developed on tracked, wheeled and biped robots by applying multi-DOF manipulators and vision systems. However, door-opening methods for six-legged robots are seldom studied, especially using 0-DOF tools to operate and only force sensing to detect. A novel door-opening method for six-legged robots is developed and implemented to the six-parallel-legged robot. The kinematic model of the six-parallel-legged robot is established and the model of measuring the positional relationship between the robot and the door is proposed. The measurement model is completely based on only force sensing. The real-time trajectory planning method and the control strategy are designed. The trajectory planning method allows the maximum angle between the sagittal axis of the robot body and the normal line of the door plane to be 45º. A 0-DOF tool mounted to the robot body is applied to operate. By integrating with the body, the tool has 6 DOFs and enough workspace to operate. The loose grasp achieved by the tool helps release the inner force in the tool. Experiments are carried out to validate the method. The results show that the method is effective and robust in opening doors wider than 1 m. This paper proposes a novel door-opening method for six-legged robots, which notably uses a 0-DOF tool and only force sensing to detect and open the door.     

图像反馈机器人视觉伺服系统理论与实验研究

对机器人视觉伺服系统的研究是机器人领域中的重要内容之一,其研究成果可应用在机器人自动避障、轨线跟踪和运动目标跟踪等问题中。本文分析了基于图像雅克比矩阵的机器人视觉伺服方法的基本原理,采用了基于图像的视觉伺服方法,直接利用图像特征来控制机器人运动,构建了自由度GRB-400工业机器人图像反馈视觉伺服系统。采用该系统进行了机器人跟踪两维平面运动目标的实验,结果验证了该方法的有效性。