Robotics and Automation, 2004. Proceedings. ICRA '04. 2004 IEEE International Conference on

This paper proposes a stable motion tracking control law for mechanical systems subject to both nonholonomic and holonomic constraints. The control law is developed at the dynamic level and can deal with model uncertainties. The proposed control law ensures the desired trajectory tracking of the configuration state of the closed-loop system. A global asymptotic stability result is obtained in the ... View full abstract»

Legged robots, such as the Sony AIBO, create opportunity to design rich motions to be executed in specific situations. In particular, teams involved in robot soccer RoboCup competitions have developed many different motions for kicking the ball. Designing effective motions and determining their effects is a challenging problem that is traditionally approached through a generate and test methodolog... View full abstract»

In this paper, a method of deriving reduced dynamic models for a class of nonholonomically constrained systems that are described on semidirect products is developed. The theory is built upon the Lagrangian reduction method for unconstrained systems on semidirect products and the Lagrangian reduction theory for nonholonomic systems defined on symmetry groups. The reduction is achieved by first app... View full abstract»

We evaluate the use of dynamic roadmaps for online motion planning in changing environments. When changes are detected in the workspace, the validity state of affected edges and nodes of a precompiled roadmap are updated accordingly. We concentrate in this paper on analyzing the tradeoffs between maintaining dynamic roadmaps and applying an on-line bidirectional rapidly-exploring random tree (RRT)... View full abstract»

Efficient calculation of the inverse dynamics of robotic mechanisms serves as a basis for a variety of control schemes. Classical algorithms for rigid multibody systems do not apply when more realistic modeling is required. The computational treatment of the emerging non-linear equations augmented by drivetrain dynamics and elasticity imposes various challenges on the algorithmic solutions. This p... View full abstract»

In the restoration work from disasters, the remote control of construction machine is required to ensure the worker's safety. However, conventional remote-controlled construction machine is larger than ordinary ones and limited in types and numbers, so there is a problem that the transportation to the destructed sites takes time and is troublesome. We have been developing the pneumatic humanoid ty... View full abstract»

In this paper we make the important observation that the attitude and angular velocity control systems for gas-jet aircraft and underwater vehicles are of a special form: they are affine control systems with constant control distributions and multi-affine drifts. For this general class of systems, we can construct (and check the existence of) bounded controls driving the system from initial to fin... View full abstract»

Navigation technology is considered that enables an underwater vehicle to compute its trajectory in real-time by utilizing range measurements from a single known location. This concept is especially attractive for small underwater vehicles where more traditional navigation technology is prohibitive due to volume constraints. By assessing local observability of the underwater vehicle and available ... View full abstract»

This paper introduces a novel continuum manipulator consisting of two flexible sections connected by rigid base plates. Each section uses 6-8 opposing contracting and extending McKibben actuators to provide two-axis bending. The contracting/extending actuator pairs are sized and positioned to provide matched rotation and torque. The experimental manipulator generates large rotation (30 - 35 degree... View full abstract»

In this paper it is shown that, for a one-legged robot, there exists a particular passive gait, of all those possible, for which the dissipated energy per meter of travel is minimized. An analytical method is used to identify the optimal gait. A SLIP model of the robot is used to simplify the dynamics. Both mechanical and electrical losses are taken into account. A numerical analysis of a complete... View full abstract»

This paper describes an efficient algorithm to generate a set of local optimal paths between two given end points in cluttered environments or over open terrain. The local optimal paths are selected from the set of shortest constrained paths through every node (one for each path) in the graph, generated by running twice a "single-source" search. The initial set of the shortest constrained paths sp... View full abstract»

In traditional trajectory planning it is usually assumed that the mean path of an ensemble of open-loop trajectories is the same as would be obtained if no noise were present. However, even zero-mean noise tends to cause the mean trajectory to deviate from the nominal one. This paper introduces a stochastic model-based motion planning method to compensate for this bias. An implementation for nonho... View full abstract»

This article presents a new approach for robot motion control, using images acquired by an on-board camera. A particularity of this method is that it can avoid reconstructing the entire scene without limiting the displacements possible. To achieve this, an image base of the environment is used to describe the navigation space. We extract from this base a sequence of overlapping images which define... View full abstract»

Progresses in sensor technology, data processing and integrated actuators has made the development of miniature flying robots fully possible. Micro VTOL systems represent a useful class of flying robots because of their strong capabilities for small-area monitoring and building exploration. In this paper we describe the approach that our lab has taken to micro VTOL evolving towards full autonomy, ... View full abstract»

Standard CCTV (close circuit television) is currently used in many pipe inspection applications, such as sewers. This human-based approach is prone to error because of the exorbitant amount of data to be assessed, and smaller anomalies or defects are likely to be overlooked reducing the chance of detection of faults at an early stage. Laser profilers for pipe inspection have been recently proposed... View full abstract»

For the design of active vibration control laws for flexible linkages in high-speed mechanisms, dynamic models incorporating the coupling of rigid body motion and flexible motion and the electromechanical coupling of transduction devices and the host linkage are very important. In the first part of this paper, the Lagrange finite element (FE) formulation is used to derive such a dynamic model for ... View full abstract»

This work considers kinematic failure tolerance when obstacles are present hi the environment. An example is given using a fully spatial redundant robot, the seven degree-of-freedom Mitsubishi PA-10. This article addresses the issue of finding a collision-free path such that a redundant robot can successfully move from a start to a goal position and/or orientation in the workspace despite any sing... View full abstract»

When a mobile robot executes a given task in human-robot co-existence environment, it is necessary for the robot to perform robust motions and to have abilities to deal with unforeseen situations. Therefore we aim to realize an intelligent and robust motion for a dual-arm mobile manipulator. To carry out a research of intelligent motion, we set a concrete task as "grasping a book and returning it ... View full abstract»

A new approach to the design and control of shape memory alloy (SMA) actuators is presented. SMA wires are divided into many segments and their thermal states are controlled individually in a binary manner. The Peltier effect is used for heating and cooling individual segments of the SMA. Unlike the traditional way of controlling the wire length by driving a current to the entire SMA wire, the new... View full abstract»

This paper presents the theory and experimental work of the adaptive plus disturbance observer (DOB) controller on underwater robot. This control scheme consists of DOB as an inner-loop compensator and a non-regressor based adaptive controller as an outer-loop controller. It is regressor-free, and is robust with respect to external disturbance as well as the variation of the nominal model used to ... View full abstract»

Autonomous underwater vehicles (AUVs) have great advantages for activities in deep sea, and expected as the attractive tool. However, AUVs have various problems which should be solved. In this paper, the self-organizing map (SOM) is applied as the clustering method for the navigation system. The SOM is known as one of the effective methods to extract the principle feature from many parameters and ... View full abstract»

The paper describes work in progress at the University of Bologna concerning the design of a new anthropomorphic robot hand. The hand is based on the modular assembly of articulated fingers that adopt an original configuration of their structure, made with rigid links connected by elastic hinges that are coaxially crossed by flexible tendons. This innovative design is suitable to host distributed ... View full abstract»

In this paper, we implement the intelligent controller hardware such as a neural network controller with an FPGA based general purpose controller and a DSP board to solve nonlinear control problems. The designed control hardware can perform a real time control of the backpropagation learning algorithm of a neural network. The basic PID control algorithms are implemented in an FPGA chip and a neura... View full abstract»

Developments on micro/nano manipulation and Internet technologies allow potential impacts on networked-micro-automation of small industrial products. However, reliable and efficient tele-micromanipulation systems with haptic feedback over the Internet face strong problems due to the nonlinear nature of the microenvironment and time-varying delays in communication lines. Towards this end, this pape... View full abstract»

In this paper, a novel fuzzy logic control system is developed for reactive navigation of a behavior-based mobile robot in dynamic environments. A combination of multiple sensors is equipped to sense the obstacles near the robot, the target location and the current robot speed. A fuzzy logic system with 48 fuzzy rules is designed, which consists of three behaviors: target seeking, obstacle avoidan... View full abstract»