Types of Robots
Robots on Earth
Typical industrial robots do
jobs that are difficult, dangerous or dull. They lift heavy objects, paint,
handle chemicals, and perform assembly work. They perform the same job hour
after hour, day after day with precision. They don't get tired and they don't
make errors associated with fatigue and so are ideally suited to performing
repetitive tasks. The major categories of industrial robots by mechanical
structure are:
- Cartesian robot /Gantry robot: Used for pick and place work, application of sealant, assembly operations, handling machine tools and arc welding. It's a robot whose arm has three prismatic joints, whose axes are coincident with a Cartesian coordinator.
- Cylindrical robot: Used for assembly operations, handling at machine tools, spot welding, and handling at diecasting machines. It's a robot whose axes form a cylindrical coordinate system.
- Spherical/Polar robot: Used for handling at machine tools, spot welding, diecasting, fettling machines, gas welding and arc welding. It's a robot whose axes form a polar coordinate system.
- SCARA robot: Used for pick and place work, application of sealant, assembly operations and handling machine tools. It's a robot which has two parallel rotary joints to provide compliance in a plane.
- Articulated robot: Used for assembly operations, diecasting, fettling machines, gas welding, arc welding and spray painting. It's a robot whose arm has at least three rotary joints.
- Parallel robot: One use is a mobile platform handling cockpit flight simulators. It's a robot whose arms have concurrent prismatic or rotary joints.
Industrial
robots are found in a variety of locations including the automobile and
manufacturing industries. Robots cut and shape fabricated parts, assemble
machinery and inspect manufactured parts. Some types of jobs robots do: load
bricks, die cast, drill, fasten, forge, make glass, grind, heat treat,
load/unload machines, machine parts, handle parts, measure, monitor radiation,
run nuts, sort parts, clean parts, profile objects, perform quality control,
rivet, sand blast, change tools and weld.
Outside the manufacturing world robots perform other important jobs. They can be found in hazardous duty service, CAD/CAM design and prototyping, maintenance jobs, fighting fires, medical applications, military warfare and on the farm.
Farmers
drive over a billion slooooww tractor miles every year on the same ground. Their
land is generally gentle, and proven robot navigation techniques can be applied
to this environment. A robot agricultural harvester named Demeter is a
model for commercializing mobile robotics technology. The Demeter harvester
contains controllers, positioners, safeguards, and task software specialized to
the needs commercial agriculture.
Some robots
are used to investigate hazardous and dangerous environments. The Pioneer robot
is a remote reconnaissance system for structural analysis of the Chornobyl Unit
4 reactor building. Its major components are a teleoperated mobile robot for
deploying sensor and sampling payloads, a mapper for creating photorealistic 3D
models of the building interior, a coreborer for cutting and retrieving samples
of structural materials, and a suite of radiation and other environmental
sensors.
An eight-legged, tethered, robot named Dante II descended into the active crater of Mt. Spurr, an
Alaskan volcano 90 miles west of Anchorage. Dante II's mission was to rappel and
walk autonomously over rough terrain in a harsh environment; receive
instructions from remote operators; demonstrate sophisticated communications and
control software; and determine how much carbon dioxide, hydrogen sulfide, and
sulfur dioxide exist in the steamy gas emanating from fumaroles in the crater.
Via
satellite, Dante II sent back visual information and other data, as well as
received instruction from human operators at control stations in Anchorage,
Washington D.C., and the NASA Ames Research Center near San Francisco. Dante II
saves volcanologists from having to enter the craters of active volcanoes. It
also demonstrates the technology necessary for a robot to explore the surface of
the moon or planets. That is, the robot must be able to walk on rough terrain in
a harsh environment, receive instructions from remote operators about where to
go next, and reach those commanded goals autonomously.
Robotic underwater rovers are used explore and gather information about many
facets of our marine environment. One example of underwater exploration is Project Jeremy, a
collaboration between NASA and Santa Clara University. Scientists sent an
underwater telepresence remotely operated 
vehicle (TROV)
into the freezing Arctic Ocean waters to investigate the remains of a whaling
fleet lost in 1871. The TROV was tethered to the surface boat Polar Star by a
cable that carried power and instructions down to the robot and the robot
returned video images up to the Polar Star. The TROV located two ships which it
documented using stereoscopic video cameras and control mechanisms like the ones
on the Mars Pathfinder. In addition to pictures, the TROV can also collect
artifacts and gather information about the water conditions. By learning how to
study extreme environments on earth, scientists will be better prepared to study
environments on other planets.
Check out Ways to Use Robots
Today, two important devices exist which are proven space robots. One is the
Remotely Operated Vehicle
(ROV) and the other is the Remote Manipulator System (RMS). The most common type of existing robotic device is the robot arm Check out Ways to Use Robots
Robots in Space
Space-based robotic technology
at NASA falls within three specific mission areas: exploration robotics, science payload
maintenance, and on-orbit servicing. Related elements are
terrestrial/commercial applications which transfer technologies generated from
space telerobotics to the commercial sector and component technology which
encompasses the development of joint designs, muscle wire, exoskeletons and
sensor technology.
An ROV can be
an unmanned spacecraft that remains in flight, a lander that makes contact with
an extraterrestrial body and operates from a stationary position, or a rover
that can move over terrain once it has landed. It is difficult to say exactly
when early spacecraft evolved from simple automatons to robot explorers or ROVs.
Even the earliest and simplest spacecraft operated with some preprogrammed
functions monitored closely from Earth. One of the best known ROV's is the Sojourner rover that was deployed by the Mars Pathfinder
spacecraft. Several NASA centers are involved in developing planetary explorers and space-based robots.
often used in industry and
manufacturing. The mechanical arm recreates many of the movements of the human
arm, having not only side-to-side and up-and-down motion, but also a full
360-degree circular motion at the wrist, which humans do not have. Robot arms
are of two types. One is computer-operated and programmed for a specific
function. The other requires a human to actually control the strength and
movement of the arm to perform the task. To date, the NASA Remote Manipulator
System (RMS) robot arm has performed a number of tasks on many space
missions-serving as a grappler, a remote assembly device, and also as a
positioning and anchoring device for astronauts working in space.
Activity TY1: Compare different uses of robots in industry and
space. Log your observations in your journal. Discuss your observations with
your team.
