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We provide a method for planning under uncertainty for robotic manipulation by partitioning the configuration space into a set of regions that are closed under compliant motions. These regions can be treated as states in a partially observable Markov decision process (POMDP), which can be solved to yield optimal control policies under uncertainty. We demonstrate the approach on simple grasping problems,...
Trotting and galloping allow a quadruped to rapidly traverse rough terrain. Modeling this motion, which is only dynamically stable, is of importance for legged robot operation and for quadrupedal animal motion estimation. Derived from an eight-step galloping cycle, this study presents a kinetic hybrid model in which the states vary based on the principal forces present. As compared to foot contact,...
This paper describes the design and control of a transfemoral prosthesis with pneumatically powered knee and ankle joints. The current version of the prosthesis serves as a laboratory testbed for purposes of controller development and testing, and as such is tethered for both power and control. A subsequent version will be self-contained, with on-board control and hot gas (monopropellant) actuation...
In this paper we present an observability analysis for a mobile robot performing SLAM with a single monocular camera. The aim is to get a better understanding of the well known intuitive behavior of these systems, such as the need for triangulation to features from different positions in order to get accurate relative pose estimates. The characterisation of the unobservable directions is made using...
A first step towards truly versatile robot assistants consists of building up experience with simple tasks such as the cooperative manipulation of objects. This paper extends the state-of-the-art by developing an assistant which actively cooperates during the point-to-point transportation of an object. Besides using admittance control to react to interaction forces generated by its operator, the robot...
A wheelchair-mounted robotic arm (WMRA) system was designed and built to meet the needs of mobility-impaired persons with limitations of upper extremities, and to exceed the capabilities of current devices of this type. The control of this 9-DoF system combines the 7-DoF robotic arm control with the 2-DoF power wheelchair control. The 3-degrees of redundancy can be optimized to effectively perform...
This paper deals with the landing motion of an articulated legged robot. Humans use a peculiar crouching motion to land safely which can be characterized by body stiffness and damping. A stiffness controller formulation is used to realize this human behavior for the robot. Using this method, the landing motion is achieved with only the desired body stiffness and damping values, without desired COG...
Autonomous navigation for wheeled mobile robots generally requires to plan a trajectory and to follow it while performing localization in the environment. In order to execute long-range motion, dead-reckoning localization is not precise enough and the robot must use landmark-based localization. Landmark-based localization can produce discontinuities in the robot position estimation, as it is well...
This paper deals with the problem of autonomous navigation for nonholonomic mobile robots. To avoid obstacles while executing a planned motion, we use a nonholonomic trajectory deformation method. Initially, this method did not take into account the velocity and acceleration bounds of the robot. The contribution of this paper is a significant improvement of the method to take into account these kinematic...
We describe a system for visual interaction developed for humanoid robots. It enables the robot to interact with its environment using a smooth whole body motion control driven by stabilized visual targets. Targets are defined as visually extracted "proto-objects" and behavior-relevant object hypotheses and are stabilized by means of a short-term sensory memory. Selection mechanisms are...
This paper characterizes the information space of a robot moving in the plane with limited sensing. The robot has a landmark detector, which provides the cyclic order of the landmarks around the robot, and it also has a touch sensor, that indicates when the robot is in contact with the environment boundary. The robot cannot measure any precise distances or angles, and does not have an odometer or...
This paper addresses the problems of automatically planning autonomous underwater vehicle (AUV) paths which best exploit complex current data, from computational estuarine model forecasts, while also avoiding obstacles. In particular we examine the possibilities for a novel type of AUV mission deployment in fast flowing tidal river regions which experience bi-directional current flow. These environments...
We discuss a ZMP-based running pattern generation for a biped robot equipped with toe springs. Our biped robot HRP-2LT has twelve active DoFs for its legs and two passive DoFs for its toes. The trajectory of the center of mass is designed to realize the specified running motion and the foot trajectories are determined to get proper spring action at lift off phases. They are interpreted into joint...
The human communication exists in various situations of our daily life. For human-robot communication or robot-robot communication, it is useful to design a communication model based on communication principal that is an entrainment phenomenon of nonlinear dynamics. In this paper, we focus on the robot motion synchronization for robot-robot communication. The robots are controlled to be entrained...
Several recent works have combined discrete and continuous motion planning methods for robot navigation and control. The basic idea of some of these works is to plan a path, by determining a sequence of neighboring discrete regions of the configuration space, and to assign a vector field that drives the robots through these regions. This paper addresses the problem of efficiently computing vector...
The least squares approach works efficiently in value function approximation, given appropriate basis functions. Because of its smoothness, the Gaussian kernel is a popular and useful choice as a basis function. However, it does not allow for discontinuity which typically arises in real-world reinforcement learning tasks. In this paper, we propose a new basis function based on geodesic Gaussian kernels,...
Human machine collaborative systems (HMCS) have been developed to enhance sensation and suppress extraneous motions or forces during surgical tasks requiring precise motion. However, to date such systems have enforced constraints on the position or path of a tool, but have not considered the dynamics of motion. Also, the focus has been on the effect of guidance of motion during a task, rather than...
We are interested in how the concept of affordances can affect our view to autonomous robot control, and how the results obtained from autonomous robotics can be reflected back upon the discussion and studies on the concept of affordances. In this paper, we studied how a mobile robot, equipped with a 3D laser scanner, can learn to perceive the traversability affordance and use it to wander in a room...
A dance partner robot has been developed as an example of platforms for realizing the effective human-robot coordination with physical interactions. This robot could dance together with a human by estimating the next step intended by the human. If the robot would mistake the step estimation, the human-robot coordination could not be continued. In this paper, an error recovery method for step selections,...
This paper introduces a signal-recognition based approach for detecting autonomous mobile robot immobilization on outdoor terrain. The technique utilizes a support vector machine classifier to form class boundaries in a feature space composed of statistics related to inertial and (optional) wheel speed measurements. The proposed algorithm is validated using experimental data collected with an autonomous...
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