Given a collection of polygonal obstacles with n vertices on the place, and any t > 1, we present an O(n logn) time algorithm that constructs a bounded-degree t-spanner of the visibility graph, without rst having to construct the visibility graph.

Let S be a set of horizontal line segments, or bars, in the plane. We say that G is a bar visibility graph, and S its bar visibility representation, if there exists a one-to-one correspondence between vertices of G and bars in S, such that there is an edge between two vertices in G if and only if there exists an unobstructed vertical line of sight between their corresponding bars. If bars are a...

In this paper, the problem of path planning for active simultaneous localization and mapping (SLAM) is addressed. In order to improve its localization accuracy while autonomously exploring an unknown environment the robot needs to revisit positions seen before. To that end, we propose a path planning algorithm for active SLAM that continuously improves robot’s localization while moving smoothly...

Abstract: The demand for high speed robotic manipulators with little or no vibrations has been a challenging research problem. In this paper, a position control for a 2 DOF single link flexible manipulator with joint elasticity is studied. It is shown that using the flatness control approach, faster response and less oscillations and overshoots can be achieved. The flat output of the linearized...

The visibility graph V(X) of a discrete point set X ⊂ R has vertex set X and an edge xy for every two points x, y ∈ X whenever there is no other point in X on the line segment between x and y. We show that for every graphG, there is a point setX ∈ R, such that the subgraph of V(X∪Z) induced by X is isomorphic to G. As a consequence, we show that there are visibility graphs of arbitrary high chr...

We compare the different control methods in learning a robotic manipulation task. The task is to push an object (a cube and sphere) from varying beginning position to a fixed goal position. Complex contact dynamics is involved. We used PPO as the learning algorithm trained from scratch with dense rewards. Comparison is performed on two dimensions: learning at joint level vs. end-effector level,...

An automated software system has been developed to allow robots to learn a generalized motor skill from demonstrations given by a human operator. Data is captured using a teleoperation suit as a task is performed repeatedly on Leonardo, the Robotic Life group's anthropomorphic robot, in different parts of his workspace. Stereo vision and tactile feedback data are also captured. Joint and end ef...

We examine the connectivity fluctuations across networks obtained when the horizontal visibility (HV) algorithm is used on trajectories generated by nonlinear circle maps at the quasiperiodic transition to chaos. The resultant HV graph is highly anomalous as the degrees fluctuate at all scales with amplitude that increases with the size of the network. We determine families of Pesin-like identi...

The navigation of autonomous mobile machines, which are referred to as robots, through unknown terrains, i.e., terrains whose models are not a priori known is considered. We deal with point-sized robots in twoand three-dimensional terrains and circular robots in two-dimensional terrains. The two-dimensional (three-dimensional) terrains are finite-sized and populated by an unknown, hut, finite, ...