This paper presents a path planning algorithm for an articulated planar robot with a static obstacle. The algorithm selects a robot part, finds a path to its goal configuration by systematic configuration space search, drags the entire robot along the path using compliant motion, and repeats the cycle until every robot part reaches its goal. The planner is tested on 11,000 random problems, whic...

This paper addresses the problem of navigating an autonomous moving entity in an environment with both stationary and movable obstacles. If a movable obstacle blocks the path of the entity attempting to reach its goal configuration, the entity is allowed to alter the placement of the obstacle by manipulation (e.g. pushing or pulling), to clear its path. This paper presents a probabilistically c...

We tested the hypothesis that area 5 of the posterior parietal cortex (PPC) contributes to interlimb coordination in locomotor tasks requiring visual guidance by recording neuronal activity in this area in three cats in two locomotor paradigms. In the first paradigm, cats were required to step over obstacles attached to a moving treadmill belt. We recorded 47 neurons that discharged in relation...

To exploit the potential benefit of multi-robot workcells, powerful motion planning and motion execution paradigms are necessary. The novel framework of elastic strips allows real-time obstacle avoidance and implicit motion coordination for multiple robots in a shared workspace. I t augments motion plans with a reactive component allowing the avoidance of unpredictably moving obstacles. The obs...

In this paper, we present an approach to obstacle avoidance for a group of unmanned vehicles moving in formation. The goal of the group is to move through a partially unknown environment with obstacles and reach a destination while maintaining the formation. We address this problem for a class of dynamic unicycle robots. Using Inputto-State Stability we combine a general class of formationkeepi...

We study the transport properties of a system of active particles moving at constant speed in a heterogeneous two-dimensional space. The spatial heterogeneity is modeled by a random distribution of obstacles, which the active particles avoid. Obstacle avoidance is characterized by the particle turning speed γ. We show, through simulations and analytical calculations, that the mean square displa...

We study force generation by a set of parallel actin filaments growing against a nonrigid obstacle, in the presence of an external load. The filaments polymerize by either moving the whole obstacle, with a large energy cost, or by causing local distortion in its shape which costs much less energy. The nonrigid obstacle also has local thermal fluctuations due to which its shape can change with t...

We investigate how to place an obstacle B within a domain in Euclidean space so as to maximize or minimize the principal Dirichlet eigenvalue for the Laplacian on nB. The shape of B is xed a priori (usually as a ball), and only its position varies. We establish that for a certain class of domains the minimizing B is in contact with @ , while the maximizing B is in the interior, typically at the...

The paper deals with kinematic control algorithms for on-line obstacle avoidance which allow a kinematically redundant manipulator to move in an unstructured environment without colliding with obstacles. The presented approach is based on the redundancy resolution at the velocity level. The primary task is determined by the end-effector trajectories and for the obstacle avoidance the internal m...