ROBOSIM: AN INTELLIGENT SIMULATOR FOR ROBOTIC SYSTEMS

ABSTRACTThe purpose of this paper is to present an update of an intelligent robotics simulator package, ROBOSIM,first introduced at Technology 2000 in 1990. ROBOSIM is used for three-dimensional geometrical modeling of robotmanipulators and various objects in their workspace, and for the simulation of action sequences performed by themanipulators. Geometric modeling of robot manipulators has an expanding area of interest because it can aid thedesign and usage of robots in a number of ways, including: design and testing of manipulators, robot action planning,on-line control of robot manipulators, telerobotic user interface, and training and education. NASA developedROBOSIM between 1985-88 to facilitate the development of robotics, and used the package to develop robotics forwelding, coating, and space operations. ROBOSIM has been further developed for academic use by its co-developerVanderbilt University, and has been used in both classroom and laboratory environments for teaching complexrobotic concepts. Plans are being formulated to make ROBOSIM available to all U.S. engineering/engineeringtechnology schools (over three hundred total with an estimated 10,000+ users per year).INTRODUCTIONIn the development of advanced robotic systems concepts for use in space and in manufacturing processes,researchers at NASA and elsewhere'have traditionally verified their designs by means of expensive engineeringprototype systems. This method, though effective, frequently required numerous re-design/fabrication cycles and aresulting high development cost. To reduce costs ROBOSIM, a graphics-based simulator for robotic systems, wasdeveloped to allow rapid prototyping of robotic systems, including robot manipulators, multi-axes positioners, othermotion-controlled mechanisms, and objects and structures in the operating environment. The reduced costs obtainablewith the graphical simulator allows experimentation with many design alternatives prior to implementation inhardware resulting in improved end-item designs.Researchers at Vanderbilt University (co-developers of ROBOSIM) have further refined the simulationpackage to fully exploit its various capabilities in the teaching of courses on robotics, mechanisms, industrial control,and advanced automation at both the undergraduate and graduate levels. ROBOSIM provides the students with agraphical means of visualizing objects and their relationships in 3-dimensional space. The relationships betweencoordinate frames that have been translated and rotated relative to one another are immediately provided in the formof transformation matrices, and they may be displayed and viewed from different viewing positions. With thesimulation system, students may actually graphically construct every manipulator they study in the classroom or inclass assignments, and then they may operate the manipulator and use it to grasp, move, and release objects, anddevelop and test action plans for using the manipulators in practical settings. The costs of doing this with physicalhardware would of course be quite prohibitive in terms of both dollars and time. ROBOSIM allows the students tobe exposed to numerous robotic systems without any of the constraints placed on use of a specific physical laboratoryroboL Furthermore, without any fear of injury the students may operate their manipulators at any hour from theirpersonal computer performing tasks ranging from arc welding to robotic care of hospitalized patients, all within theconfines of the interactive simulation environment provided by ROBOSIM!