机器人球关节的优化控制

本文提出了机器人步进型球关节点位时间最优控制和改进的加密双判别函数插补原理,并分别应用于PTP与CP控制中,通过原理探索、判据定义和编程运行,在实际试验中表明具有良好控制效果。     

七自由度仿人臂形操作机器人的运动学问题

本文根据七自由度仿人臂形操作机器人的结构特点,借助齐次变换矩阵,建立了运动学正问题的数学模型.并利用几何等同性条件,建立了运动学逆问题的数学模型,同时还建立了基于点位控制的轨迹规划数学模型,最后给出求解操作机器人各质点的速度和加速度的算法.     

Robot Dynamic Modeling Using a Power Flow Approach with Application to Biped Locomotion

In this paper, we present a method for robots modeling called bidirectional dynamic modeling. This new method takes into account the gear efficiency and the direction of power transmission in the gears. Epicyclic gearboxes have often different efficiencies in the two directions of power transmission. The characteristics of the chain of transmission must then be taken into consideration in order to describe the dynamic behavior of robots. The two directions of power flow can indeed occur in robot motions. Depending on that direction the dynamic model is different. The bidirectional dynamic modeling is experimentally applied to a bipedal walking robot. Our method exhibits a better accuracy over classical modeling. Moreover, when applied to computed torque control, the bidirectional model increases the tracking performances.     

OTTER: The design and development of an intelligent underwater robot

Recent advances in sensing and intelligent control technologies open a whole new dimension in underwater autonomy. However, before truly-capable, autonomous underwater robots can be created for subsea intervention and exploration, many research issues must be first investigated and developed experimentally on testbed platforms.OTTER is an underwater robot designed to be used as a testbed for autonomous technologies. Both OTTER's hardware and software systems are configured to support simultaneous development and testing of different concepts for underwater robotic by independent researchers. A general control-software framework enables common access to all subsystems and avoids the duplication of basic robotic functionality jointly required by all projects. Additionally, the new autonomous technologies enabled by the results of individual research are mutually compatible and can be easily integrated into a single robotic system. Examples of new technologies demonstrated on the OTTER underwater robot include control from a real-time vision-sensing system, coordinated arm/vehicle control, and control from 3D graphical user interfaces.     

机器人机构柔性研究

本文研究并首次提出了六自由度机器人机构柔度的定量计算方法,编制了相应的应用软件,以各种典型关节型机器人为例,在 SGI 工作站上实现了柔度的定量分析计算及其三维图形仿真,给出了工作空间内平行于子午面的任意节面上机构等柔度曲线.研究成果为机器人的性能分析。避障,轨迹规划等研究提供了有力的手段.     

并联机器人轨迹跟踪变结构控制的研究

本文根据并联机器人控制的特点，将离散变结构理论应用于并联机器人的轨迹控制，引进了离散趋近律的概念，给出了实用的离散变结构控制算法，仿真表明，该方法对并联机器人轨迹踪具有良好的控制效果。     

应用DDS方法辨识机器人振动的模态参数

本论文应用DDS方法将机器人振动系统的运动微分方程转换到一个自回归滑动平均(ARMA)模型.根据 ARMA 模型的性质,给出了ARMA模型的特征参数与机器人振动模型之间的关系,并通过Householder-OUSEHOLDER变换的最小二乘法.对机器人振动系统的模态参数进一步识别.     

Direct adaptive control of robotic systems

This paper presents a new approach to adaptive motion control of an important class of robotic systems. The control schemes developed using this approach are very simple and computationally efficient since they do not require knowledge of either the mathematical model or the parameter values of the robotic system dynamics. It is shown that the control strategies are globally stable in the presence of bounded disturbances, and that the size of the tracking errors can be made arbitrarily small. The proposed controllers are very general and are implementable with a wide variety of robotic systems, including both open- and closed-kinematic-chain manipulators. Computer simulation results are given for a seven degree-of-freedom (DOF) Robotics Research Corporation Model K-1607 arm. These results demonstrate that accurate and robust trajectory tracking can be achieved by using the proposed schemes.     

Methods for the Reduction of Odometry Errors in Over-Constrained Mobile Robots

This paper presents an analysis of odometry errors in over-constrained mobile robots, that is, vehicles that have more independent motors than degrees of freedom. Examples of over-constrained vehicles are the various 6-wheeled Mars Rovers like Rocky-7, Rocky-8, or Fido.Based on our analysis we developed two novel measures aimed at reducing odometry errors. We also developed a novel method that serves as a framework for the implementation of the two new measures, as well as for other, conventional error reducing measures.One of the two new measures, called Fewest Pulses Measure, makes use of the observation that most terrain irregularities, as well as wheel slip, result in an erroneous overcount of encoder pulses. The second new measure, called Cross-coupled Control Measure, optimizes the motor control algorithm of the robot to reduce synchronization errors that would otherwise result in wheel slip with conventional controllers.The novel method that serves as a framework for other measures is based on so-called Expert Rules. In this paper we formulate three expert rules aimed at reducing dead-reckoning errors. Two of these expert rules are related to the foregoing discussion on error reducing measures. The third expert rule adds a gyroscope to the system and we re-examine the effectiveness of the odometry error-reducing measures in the context of this addition.In the work described in this paper we modified a Pioneer AT skid-steer platform by providing it with four independent drive motors and encoders. We implemented our error-reducing measures and the expert rule method on this over-constrained platform and present experimental results.     

Mechanical assessment of time optimal robot motion

The use of time optimal path planning can speed up robots on assembly lines and allow them to run faster, increasing their productivity. This paper seeks to develop a more complete understanding of the nature of time-optimal point-to-point trajectories for polar coordinate robots and intends to show how effective direct numerical methods are in computing optimal control solutions, including the resolution of complicated motor switching structures. In time optimal robot point-to-point motion there is generically one robot axis that has the hardest time reaching its endpoint. And then, to whatever extent other axes have extra freedom, it must be used to help the axis with the hardest task, whenever possible. Such assistance makes use of different mechanical interaction forces and effects. In this paper we examine one basis type of robot, the polar coordinate robot, and analyze all types of forces during optimal motions, in order to develop an understanding of optimal maneuvers.Formerly Researcher at the Institute for Scientific Computing, University of Heidelberg Germany