Engineering topics

Basta, Robert A.

Publications and source records attributed to Basta, Robert A..

4 records

NASA NTRS1988

Detecting and avoiding collisions between two robot arms in a common workspace

A novel approach to collision detection is presented and methods of avoiding collisions are discussed. Collisions are assumed to be between the wrists of two robots (which correspond to the upper three links of PUMA manipulators). A sphere model for the wrist is employed because it is rotationally invariant and computationally efficient. The collision detection algorithm involves obtaining the potential collision path segments along the straight line trajectories without considering the motion characteristics, and mapping the potential collision segment information into the time domain to obtain the space-time collisions.

Basta, Robert A.↗

NASA NTRS1988

Collision detection for planning collision-free motion of two robot arms

The authors focus on collision detection for planning collision-free motion of two robot arms in a common workspace. A collision-free motion is obtained by detecting collisions along the straight-line trajectories of the robots using a sphere model for the wrists and then replanning the paths and/or trajectories of one or both of the robots to avoid collisions. A novel approach to collision detection is presented and a discussion on collision avoidance is given.

Basta, Robert A.↗

NASA NTRS1987

Collision-free motion of two robot arms in a common workspace

Collision-free motion of two robot arms in a common workspace is investigated. A collision-free motion is obtained by detecting collisions along the preplanned trajectories using a sphere model for the wrist of each robot and then modifying the paths and/or trajectories of one or both robots to avoid the collision. Detecting and avoiding collisions are based on the premise that: preplanned trajectories of the robots follow a straight line; collisions are restricted to between the wrists of the two robots (which corresponds to the upper three links of PUMA manipulators); and collisions never occur between the beginning points or end points on the straight line paths. The collision detection algorithm is described and some approaches to collision avoidance are discussed.

Basta, Robert A.↗

NASA NTRS1987

Multiple arm coordination using concurrent processing

The use of concurrent processing for robot arm coordination is considered, and a hierarchically structured set of routines for the completion of coordinated tasks is discussed. Concurrent programming controls interacting concurrent processes by providing techniques to handle the problems of mutual exclusion, synchronization, and communication. The process is demonstrated for the example of the producer-consumer problem. Software supporting a concurrent environment to control a robotic system is being developed in which parallel rather than sequential thought processes are used.

Basta, Robert A.↗