2008 IEEE/RSJ International Conference on Intelligent Robots and Systems

In this paper, we study the performance of various algorithms for fast online identification of environment impedance during robotic contact tasks. In particular, we evaluate and compare algorithms with regard to their convergence rate, computational complexity and sensitivity to noise for different environments using a single degree-of-freedom experimental setup. The results provide some guidelin... View full abstract»

Building on the assumption that identification of a sufficient number of isoclines of an environmental field (such as the ocean bottom terrain) allows efficient reconstruction of the field, in this paper, a sequel to [1], we describe a system where a group of robots in a spacial arrangement (a regular polygon centred around a lead robot) locally construct the field (measured at the locations of th... View full abstract»

This paper presents the singularity analysis of four 3-DOF symmetric zero-torsion parallel mechanisms. These mechanisms are composed of three identical legs ending with a spherical joint that is constrained to move in one of three equally spaced planes intersecting at one line. The computation of the singularity loci is based on the degeneracy of the system of screws applied on the platform by the... View full abstract»

Online estimates of unknown environment dynamics are used for the control of robotic contact tasks. The Hunt-Crossley nonlinear dynamic model of environments has been shown to be more consistent with the physics of contact, compared to the classical linear models, such as Kelvin-Voigt. This paper proposes a new method for online parameter estimation of Hunt-Crossley model and provides a mild set o... View full abstract»

When robot maintenance impedes the operation of other robots in a seaport container terminal, the operational efficiency is reduced. Therefore, robot reliability is necessary. In this paper, we propose a reactive robot control system with hybrid operational models for flexible and efficient container handling in consideration of robot reliability. For this purpose, we focus on three operational mo... View full abstract»

This paper investigates a human body posture estimation method based on the back projection of human silhouette images extracted from multi-camera images. The multi-camera system is based on a server-client system with local network of 1000 Base-T to achieve a voxel 3D reconstruction of human body posture in real-time. In order to extract significant points of the human body such as head, neck, sh... View full abstract»

The rehabilitation robot Lokomat allows automated treadmill training for patients with neurological gait disorders. The basic position control approach for the robot has been extended to patient-cooperative strategies. These strategies provide more freedom and allow patients to actively influence their training. However, patients are likely to need additional support during patient-cooperative tra... View full abstract»

Pelvic motions are of great importance while walking, and have thus to be taken into account when developing and controlling rehabilitation devices. This paper will first introduce a new reeducation device for paraplegic people: the WalkTrainer. This device is composed of a leg and pelvic orthosis, an active bodyweight support and closed loop muscle stimulation. Second, the six degrees of freedom ... View full abstract»

The design procedure for a totally decoupled XY flexure parallel kinematic manipulator is presented in this paper. The designed XY stage is featured with flexure hinges and a relatively simple structure. The output decoupling is allowed by the employment of compound parallelogram flexure, and the input decoupling is implemented by actuation isolation which is enabled by the double compound paralle... View full abstract»

In this paper, an improved algorithm to measure Chinapsilas EMU spacesuit joint damping parameters for the old passive robot system is presented. The measuring principle is based on robot kinematics and dynamics. Firstly, a kinematic model of the passive robot and the EMU spacesuitpsilas arm is built according to the special mechanical structure. Secondly, improved methods of solving the inverse k... View full abstract»

One of the main challenges in telerobotics is the selection of control architectures and control parameters, which are able to robustly stabilize the overall teleoperation system despite of changing human operator and environment impedances. In this paper robust stability of different types of bilateral control algorithms for admittance-type devices is analyzed. Hereby stability of the system is i... View full abstract»

Robots are efficient and economic for in-pipe inspection tasks. In this paper, we deal with versatility and multifunction of in-pipe inspection robots. A versatile platform equipped with one driving motor is the main body of multifunctional mobile unit (MMU) that performs inspection tasks. We have developed three kinds of MMU by fixing different assemblies on the proposed versatile platform. MMU1 ... View full abstract»

This paper presents and describes the approach for achieving long distance autonomous navigation with a mobile robot on outdoor cluttered pedestrian paths. The task was to finish an event launched by the City of Tsukuba in Japan, called ldquoReal World Robot Challengerdquo, of navigating 1km autonomously in a real environment with real pedestrians and bicycles. The hardware, software and strategy ... View full abstract»

This paper introduces a localization based on GPS and laser measurements for urban and non-urban outdoor environments. In this approach, the GPS pose is Kalman filtered using wheel odometry and inertial data and tightly integrated into a Monte Carlo localization based on 3D laser range data and a line feature reference map. By applying to this kind of sensor fusion, global localization as well as ... View full abstract»

This paper proposed a small and light actuator based on an easy ON-OFF control to movement walking robot. We named a flexible, flat plate to FFP actuator as an actuator of a flexible locomotion robot. The FFP actuator is a versatile actuator that mechanically obtains flexible displacement by combining functional materials like the shape-memory alloy with a simple lamina structure lightly not broke... View full abstract»

Walking fruit flies are attracted by near-by objects. They estimate the distance to these objects by the parallax motion of their images on the retina. Here we provide evidence from robot simulations that distance is assessed by motion integration over large parts of the visual field and time periods of 0.5 s to 2 s. The process in flies is not selective to image motion created by the self-motion ... View full abstract»

In an electric bicycle, two strategies are taken up to stabilize the running motion of a bicycle. One is the control of its center of gravity (CG), and the other is the control of its steering angle of handle. In general, the control of the CG is used a pendulum. In addition, the motion of a bicycle often possesses a lean angle with respect to vertical direction. In this situation, the proposed sy... View full abstract»

This paper presents a new mechanism for artificial fingers. It enables adduction/abduction of the MP joint in addition to the synergetic flexion/extension of the DIP, PIP and MP joints. The key mechanism is the newly invented double planetary gear system (DPGS) that allows three DOF motions of the finger in a compact placement of all actuators in a palm. The DPGS receives three input torques; two ... View full abstract»

Camera calibration is an important step for vision-based stabilization of unmanned aerial vehicles (UAV). The goal of this paper is to develop a method for automatic calibration of a catadioptric camera so that it can be easily run before mounting the camera on the UAV or even during the flight to deal with vibrations or shocks. Whereas existing works can provide interesting results, they suffer f... View full abstract»

Walknet, a biological inspired neural network, has been proposed to control walking of a 6-legged; 18 DoF walker. Control of stance movement is difficult because all legs in stance are mechanically coupled. Based on the idea of velocity feedback, recently a specific revision, local positive velocity feedback, has been proposed to solve this problem using an extremely decentralised architecture. In... View full abstract»

This paper proposes a method for near-optimal navigation of high speed mobile robots on uneven terrain. The method relies on a layered control strategy. A high-level planning layer generates an optimal desired trajectory through uneven terrain. A low-level navigation layer guides a robot along the desired trajectory via a potential field-based control algorithm. The high-level planner is guarantee... View full abstract»

We present a probabilistic architecture for solving generically the problem of extracting the task constraints through a programming by demonstration (PbD) framework and for generalizing the acquired knowledge to various situations. In previous work, we proposed an approach based on Gaussian mixture regression (GMR) to find a controller for the robot reproducing the essential characteristics of a ... View full abstract»

This article presents results concerning recognition and classification of the qualitative-type range measurement errors in a time-of-flight principle based 2D laser scanner used on mobile robots for navigation. The main source of the qualitative uncertainty are the mixed measurements. This effect has been investigated experimentally and explained by analyzing the physical phenomena underlying the... View full abstract»

This article provides a tracking scheme for 6 DOFpsilas parallel robots. It is based on a controller/observer combination with an additional compensation of the desired dynamics. The latter is necessary to avoid an online calculation of the direct kinematics. However, it introduces systematic errors. To take such deviations into account a passivity based formalism is used. The resulting approach i... View full abstract»