Dynamic Object Tracking Control for a Non-Holonomic Wheeled Autonomous Robot

[[abstract]]This paper is devoted to design and implement a non-holonomic wheeled mobile robot that possesses dynamic object-tracking capability by using real-time image processing. Two motion control laws are proposed using Lyapunov’s direct method and computed-torque method. Simulation results illustrate the effectiveness of the developed schemes. The overall experimental setup of the mobile robot developed in this paper is composed of a Windows based personal computer, Programmable Interface Controllers, a mobile robot, and an omni-directional vision system. Finally, the image-based real-time implementation experiments of the mobile robot demonstrate the feasibility and effectiveness of the proposed schemes.[[incitationindex]]EI[[booktype]]紙本[[booktype]]電子

Monocular SLAM for a Small-size Humanoid Robot

100學年度研究獎補助論文[[abstract]]The paper presents a algorithm of visual simultaneous localization and mapping (vSLAM) for a small-size humanoid robot. The algorithm includes the procedures of image feature detection, good feature selection, image depth calculation, and feature state estimation. To ensure robust feature detection and tracking, the procedure is improved by utilizing the method of Speeded Up Robust Features (SURF). Meanwhile, the procedures of image depth calculation and state estimation are integrated in an extended Kalman filter (EKF) based estimation algorithm. All the computation schemes of the visual SLAM are implemented on a small-size humanoid robot with low-cost Window-based PC. Experimentation is performed and the results show that the performance of the proposed algorithm is efficient for robot visual SLAM in the environments.[[notice]]補正完畢[[incitationindex]]EI[[booktype]]紙

Design of an Action Select Mechanism for Soccer Robot Systems Using Artificial Immune Network

[[abstract]]In a small-size robot soccer game, the game strategy is implemented by two major procedures, namely, Role Selection Mechanism (RSM) and Action Select Mechanism (ASM). In role-select procedure, a formation is planned for the soccer team and a role is assigned to each individual robot. In action-select procedure, each robot executes an action provided by an action selection mechanism to fulfill its role-playing. The RSM was often designed efficiently by using the geometry approach. However, the ASM developed based on geometry approach will become a very complex procedure. In this paper, a novel ASM for soccer robots is proposed by using the concepts of artificial immune network (AIN). This AIN-based ASM provides an efficient and robust algorithm for robot role select. Meanwhile, a reinforcement learning mechanism is applied in the proposed ASM to enhance the response of the adaptive immune system. Simulation and experiment are carried out in this paper to verify the proposed AIN-based ASM and the results show that the proposed algorithm provide an efficient and applicable algorithm for mobile robots to play soccer game.[[notice]]補正完畢[[incitationindex]]EI[[booktype]]紙

Path planning for robot-assisted grinding processes

[[abstract]]Path planning for a robot-assisted surface finishing system with an active torque controller is presented. We utilize a dexterous manipulator to attain the desired position and orientation in three-dimensional space during finishing processes. A single-axis active controller consists of a DC motor and a software observer is attached to the robot wrist and used to actuate a pneumatic hand-grinder. The torque observer is designed to sense the grinding contact force based on the driving current and output position of the motor. Zigzag and fractal paths on curved surfaces are designed for the grinding processes. In order to determine an ideal grinding condition, Taguchi's method for experimental design is utilized. We choose four grinding conditions, namely, path pattern, grinding contact pressure, tool diameter, and feed rate. Tendencies of these factors can be found from the experiments. In this research, the prototype of a robot-assisted finishing system is constructed and tested on a Tatung A330 robot. The experimental results show that the robot-assisted finishing system functions well under a variety of grinding conditions.[[conferencetype]]國際[[conferencedate]]20010521~20010526[[conferencelocation]]Seoul, Kore

Simulation of Mechanical Systems With Multiple Frictional Contacts

There are several applications in robotics and manufacturing in which nominally rigid objects are subject to multiple frictional contacts with other objects. In most previous work, rigid body models have been used to analyze such systems. There are two fundamental problems with such an approach. Firstly, the use of frictional laws, such as Coulomb\u27s law, introduce inconsistencies and ambiguities when used in conjunction with the principles of rigid body dynamics. Secondly, hypotheses traditionally used to model frictional impacts can lead to solutions which violate principles of energy conservation. In this paper these problems are explained with the help of examples. A new approach to the simulation of mechanical systems with multiple, frictional constraints is proposed which is free of inconsistencies

Analysis and Simulation of Mechanical Systems With Multiple Frictional Contacts

In many engineering applications such as assembly of mechanical components, robot manipulation, gripping, fixturing and part feeding, there are situations in which a rigid body is subject to multiple frictional contacts with other bodies. It is proposed to develop a systematic method for the analysis and simulation of such systems. A detailed study is presented on rigid body impact laws, and the assumption of contact compliance is investigated

Data Association and Map Management for Robot SLAM using Local Invariant Features

[[abstract]]To build a persistent map with visual landmarks is one of the most important steps for implementing the visual simultaneous localization and mapping (SLAM). The corner detector is a common method utilized to detect visual landmarks for constructing a map of the environment. However, due to the scalevariant characteristic of corner detection, extensive computational cost is needed to recover the scale and orientation of corner features in SLAM tasks. The purpose of this paper is to build the map using a local invariant feature detector, namely speeded-up robust features (SURF), to detect scale- and orientation-invariant features as well as provide a robust representation of visual landmarks for SLAM. The procedures of detection, description and matching of regular SURF algorithms are modified in this paper in order to provide a robust data-association of visual landmarks in SLAM. Furthermore, the effective method of map management for SURF features in SLAM is also designed to improve the accuracy of robot state estimation.[[notice]]補正完畢[[conferencetype]]國際[[conferencedate]]20130804~20130807[[booktype]]電子版[[iscallforpapers]]Y[[conferencelocation]]Takamatsu, Japa

Dynamics of Rigid Bodies Undergoing Multiple Frictional Contacts

There are several applications in robotics and manufacturing in which nominally rigid objects are subject to multiple frictional contacts with other objects. In most previous work, rigid body models have been used to analyze such systems. There are two fundamental problems with such an approach. Firstly, the use of frictional laws, such as Coulomb\u27s law, introduce inconsistencies and ambiguities when used in conjunction with the principles of rigid body dynamics. Secondly, hypotheses traditionally used to model frictional impacts can lead to solutions which violate principles of energy conservation. In this paper these problems are explained with the help of examples. A new approach to the simulation of mechanical systems with multiple, frictional constraints is proposed which is free of inconsistencies

Calibration of RGB-D sensors for Robot SLAM

[[abstract]]This paper presents a calibration procedure for a Kinect RGB-D sensor and its application to robot simultaneous localization and mapping (SLAM). The calibration procedure consists of two stages: in the first stage, the RGB image is aligned with the depth image by using the bilinear interpolation. The distorted RGB image is further corrected in the second stage. The calibrated RGB-D sensor is used as the sensing device for robot navigation in unknown environment. In SLAM tasks, the speeded-up robust features (SURF) are detected from the RGB image and used as landmarks for the environment map. The depth image could provide the stereo information of each landmark. Meanwhile, the robot estimates its own state and landmark locations by mean of the extended Kalman filter (EKF). The EKF SLAM has been carried out in the paper and the experimental results showed that the Kinect sensors could provide reliable measurement information for mobile robots when navigating in unknown environment.[[notice]]補正完畢[[journaltype]]國外[[incitationindex]]EI[[ispeerreviewed]]Y[[booktype]]電子版[[countrycodes]]CH

Obesity and the microvasculature

Overweight and obesity are thought to significantly influence a person's risk of cardiovascular disease, possibly via its effect on the microvasculature. Retinal vascular caliber is a surrogate marker of microvascular disease and a predictor of cardiovascular events. The aim of this systematic review and meta-analysis was to determine the association between body mass index (BMI) and retinal vascular caliber. Relevant studies were identified by searches of the MEDLINE and EMBASE databases from 1966 to August 2011. Standardized forms were used for data extraction. Among over 44,000 individuals, obese subjects had narrower arteriolar and wider venular calibers when compared with normal weight subjects, independent of conventional cardiovascular risk factors. In adults, a 1 kg/m(2) increase in BMI was associated with a difference of 0.07 μm [95% CI: -0.08; -0.06] in arteriolar caliber and 0.22 μm [95% CI: 0.21; 0.23] in venular caliber. Similar results were found for children. Higher BMI is associated with narrower retinal arteriolar and wider venular calibers. Further prospective studies are needed to examine whether a causative relationship between BMI and retinal microcirculation exists