小型月球探测器高精度姿态指向控制

针对小型月球探测器三轴姿态高指向精度和高稳定度的要求 ,采用欧拉动力学和四元数方法描述 ,建立了小型月球探测器环月阶段动力学模型 ,分析了由 3个轻型反作用轮正交安装组成的姿态稳定控制系统 ,给出了一种拟PD姿态指向控制规律。对所设计的指向控制律进行了数学仿真 ,结果表明可达到 0 .0 1°/s的稳定度和 0 .3°的指向精度 ,验证了该控制规律的可行性。     

Assistant force compensation for hand movement of patients by using exogenous signals and/or neurophysiological signals

Because functional diseases of the brain can cause disabilities related to human movement control, a compensation method was developed for improving the performance of hand movements. The compensation for human hand movements can be carried out by adding an assistant force that is generated from artificial equipment attached to a human arm. From the experiment on visual target tracking, it was found that the tracking trajectory was adequately represented by a dynamic model of the motion of an articulated industrial robot arm, and the different abilities for movement control among healthy people and patients were classified by different model parameters as position loop gain, velocity loop gain, and response delay. Dynamic force compensation was approached by considering the different control features of the patients. The effectiveness of the proposed compensation method was verified in a simulation study on an actual industrial robot arm. A human-machine interface, e.g., a brain-computer interface (BCI), for realizing the control of artificial equipment to compensate for human hand movements is also presented and discussed.     

Design and Use of Linear Models for Image Motion Analysis

Linear parameterized models of optical flow, particularly affine models, have become widespread in image motion analysis. The linear model coefficients are straightforward to estimate, and they provide reliable estimates of the optical flow of smooth surfaces. Here we explore the use of parameterized motion models that represent much more varied and complex motions. Our goals are threefold: to construct linear bases for complex motion phenomena; to estimate the coefficients of these linear models; and to recognize or classify image motions from the estimated coefficients. We consider two broad classes of motions: i) generic motion features such as motion discontinuities and moving bars; and ii) non-rigid, object-specific, motions such as the motion of human mouths. For motion features we construct a basis of steerable flow fields that approximate the motion features. For object-specific motions we construct basis flow fields from example motions using principal component analysis. In both cases, the model coefficients can be estimated directly from spatiotemporal image derivatives with a robust, multi-resolution scheme. Finally, we show how these model coefficients can be use to detect and recognize specific motions such as occlusion boundaries and facial expressions.     

Efficient Dynamic Constraints for Animating Articulated Figures

This paper presents an efficient dynamics-based computer animation system for simulating and controlling the motion of articulated figures. A non-trivial extension of Featherstone's O(n) recursive forward dynamics algorithm is derived which allows enforcing one or more constraints on the animated figures. We demonstrate how the constraint force evaluation algorithm we have developed makes it possible to simulate collisions between articulated figures, to compute the results of impulsive forces, to enforce joint limits, to model closed kinematic loops, and to robustly control motion at interactive rates. Particular care has been taken to make the algorithm not only fast, but also easy to implement and use. To better illustrate how the constraint force evaluation algorithm works, we provide pseudocode for its major components. Additionally, we analyze its computational complexity and finally we present examples demonstrating how our system has been used to generate interactive, physically correct complex motion with small user effort.     

An efficient steering control formulation for the articulated body mobile robot “KR-II”

This paper introduces an efficient steering control method for the articulated body mobile robot Koryu-II (KR-II). KR-II is a real robot, composed of six cylindrical segments linked in series and has a long snake-like appearance. The main issue on KR-II's steering control is, given from a remote human operator the velocity and orientation commands for the foremost segment, to automatically generate joint commands for all the following segments, such that they follow the foremost segment's trajectory. The derived method is based on a trajectory planning scheme in the inertial reference frame, and is feasible for real time computation. It also presents good energy efficiency and trajectory tracking performance characteristics, and can be extended for KR-II's W-Shaped Configuration steering control, which augments the lateral stability of the robot, essential for locomotion over uneven terrain. The validity of these methods are verified by experiments on the mechanical model KR-II.     

基于SD*lite的月球车任务规划算法

月球车任务规划是在给定初始位置和目标位置,满足月面地形约束、工作模式约束以及能量约束的前提下,规划出月球车最优的路径。设计了一种月球车任务规划的模型,提出了一种基于SD*lite算法的规划器,在原有SD*lite算法的基础上进一步考虑了对可用资源的限制;它可以协助月球车在考虑太阳能帆板的能量约束的条件下,合理避障最终达到目标点,使规划的轨迹更符合实际。     

Development of Arm Equipped Single Wheel Rover: Effective Arm-Posture-Based Steering Method

We have been proposing a new planetary rover system named SMC Rover. This system consists of one main body and detachable units, which can work as child rovers, and also become driving units of the main body. Each detachable unit named Uni-Rover consists of a single manipulator mounted on a wheel. Prototype models of the Uni-Rover and the SMC Rover have been already developed. This paper describes a new method of trajectory modeling for the Uni-Rover using the relation between arm posture and turning radius. At first, an intuitively recognizable model which uses zero slip angle is introduced. However, because this intuitive model has some problems, a new solution which considers the loss of friction on the wheel and on the caster is also discussed. The validity of the presented method is verified by experiments with an actual mechanical model. Moreover, an effective steering method which considers the margin of the energy stability is introduced.Kazuhiro Motomura is a Ph.D candidate at the Tokyo Institute of Technology (Tokyo Tech). In 2001 he was admitted to skip the fourth grade of the bachelor course in the Department of Mechano-Aerospace engineering at Tokyo Tech to enterthe master course in the Department of Mechanical and Aerospace Engineering at the same Institute. He received the B.E. degree in National Institution for Academic Degrees an University Evaluation in 2002, and received the M.E. degree in the Department of Mechanical and Aerospace Engineering at Tokyo Tech in 2003. He has been a research fellow of the Japan Society for the Promotion of Science from 2004. He awarded the Incentive Award for the presentation in the 17th RSJ Annual Conference in 2001, and the Finalists for the Best Video Award in the IEEE International Conference on Robotics and Automation in 2003. His research interests include design of robotic mechanisms and control of mobile robots. He studies about the development of planetary rovers.Atsushi Kawakami awarded the chance to skip fourth gradein the bachelor course of Department of Mechano-Aerospace engineering in Tokyo Institute of Technology, and entered the master course in 1997. He received the M.E. and Dr. E. degrees in Department of Mechanical Engineering Science in Tokyo Institute of Technology in 1999 and 2003, respectively. From 2003, he is a post-doctoral researcher. His research interest is in design of robotic mechanisms. He studies about the development of planetary rover. He awarded the Incentive Award for the presentation in the 17th RSJ Annual Conference in 2001, and the Finalists for the Best Video Award in the IEEE International Conference on Robotics and Automation in 2003. He also acts as an organizer and lecturerin several hands on robots competitions that aim at the promotion and education for the beginners.Shigeo Hirose was born in Tokyo in 1947. He received the B. E. degree with first class honors in Mechanical Engineering from Yokohama National University in 1971, and the M. E. and Dr. E. degrees in Control Engineering from the Tokyo Institute of Technology in 1973 and 1976, respectively. From 1976 to 1979 he was a Research Associate, from 1979 to 1992 an Associate Professor and since 1992 he has been a Professor in the Department of Mechanical and Aerospace Engineering at the Tokyo Institute of Technology. He is the Fellow of both IEEE and Japanese Society of Mechanical Engineers. His research interest is in design of novel robotic mechanisms and its control. He awarded more than 30 prizes from academic societies; these include the first Pioneer in Robotics and Automation Award in 1999 and Best Conference Paper Award in 1995 both from IEEE Robotics & Automation Society. Prof. Hirose has published more than 200 academic papers as well as several books, including Snake Inspired Robots (Kogyo-chosakai Publishing Co. Ltd, 1987, in Japanese), Robotics (Shokabo Publishing Co. Ltd., 1987, in Japanese), and Biologically Inspired Robots (Oxford University Press,1993).     

Image Manifolds which are Isometric to Euclidean Space

Recently, the Isomap procedure [10] was proposed as a new way to recover a low-dimensional parametrization of data lying on a low-dimensional submanifold in high-dimensional space. The method assumes that the submanifold, viewed as a Riemannian submanifold of the ambient high-dimensional space, is isometric to a convex subset of Euclidean space. This naturally raises the question: what datasets can reasonably be modeled by this condition? In this paper, we consider a special kind of image data: families of images generated by articulation of one or several objects in a scene—for example, images of a black disk on a white background with center placed at a range of locations. The collection of all images in such an articulation family, as the parameters of the articulation vary, makes up an articulation manifold, a submanifold of L ². We study the properties of such articulation manifolds, in particular, their lack of differentiability when the images have edges. Under these conditions, we show that there exists a natural renormalization of geodesic distance which yields a well-defined metric. We exhibit a list of articulation models where the corresponding manifold equipped with this new metric is indeed isometric to a convex subset of Euclidean space. Examples include translations of a symmetric object, rotations of a closed set, articulations of a horizon, and expressions of a cartoon face. The theoretical predictions from our study are borne out by empirical experiments with published Isomap code. We also note that in the case where several components of the image articulate independently, isometry may fail; for example, with several disks in an image avoiding contact, the underlying Riemannian manifold is locally isometric to an open, connected, but not convex subset of Euclidean space. Such a situation matches the assumptions of our recently-proposed Hessian Eigenmaps procedure, but not the original Isomap procedure.     

装载机铰接系统铰点位置对铰点载荷的影响

研究了装载机车架铰接系统铰点位置对铰点载荷的影响；给出了ＺＬ５０装载机铰点纵向位置、上下铰点距离、下铰点到路面距离与铰点径向、轴向载荷的关系；得出了一些对铰接式车辆铰接系统的设计及改进具有一定指导意义的结论。