Autonomous robot

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Autonomous robots are robots which can perform desired tasks in unstructured environments without continuous human guidance. Many kinds of robots have some degree of autonomy. Different robots can be autonomous in different ways. A high degree of autonomy is particularly desirable in fields such as space exploration, where communication delays and interruptions are unavoidable. Other more mundane uses benefit from having some level of autonomy, like cleaning floors, mowing lawns, and waste water treatment [1].

Some modern factory robots are "autonomous" within the strict confines of their direct environment. Maybe not every degree of freedom exists in their surrounding environment but the work place of the factory robot is challenging and can often be unpredictable or even chaotic. The exact orientation and position of the next object of work and (in the more advanced factories) even the type of object and the required task must be determined. This can vary unpredictably (at least from the robot's point of view).

One important area of robotics research is to enable the robot to cope with its environment whether this be on land, underwater, in the air, underground, or in space.

A fully autonomous robot has the ability to

Gain information about the environment.
Work for an extended period without human intervention.
Move either all or part of itself throughout its operating environment with human assistance.
Avoid situations that are harmful to people, property, or itself.

An autonomous robot may also learn or gain new capabilities like adjusting strategies for accomplishing its task(s) or adapting to changing surroundings.

Autonomous robots still require regular maintenance, as do other machines.

1 Examples of progress towards commercial autonomous robots
2 See also
3 External links

[edit] Examples of progress towards commercial autonomous robots

[edit] Self-maintenance

The first requirement for physical autonomy is the ability for a robot to take care of itself. Many of the battery powered robots on the market today can find and connect to a charging station, and some toys like Sony's Aibo are capable of self-docking to charge their batteries.

Self maintenance is based on "proprioception", or sensing one's own internal status. In the battery charging example, the robot can tell proprioceptively that its batteries are low and it then seeks the charger. Another common proprioceptive sensor is for heat monitoring. Increased proprioception will be required for robots to work autonomously near people and in harsh environments.

Common proprioceptive sensors are

Thermal

Hall Effect

Optical

Contact

[edit] Sensing the Environment

Exteroception is sensing things about the environment. Autonomous robots must have a range of environmental sensors to perform their task and stay out of trouble.

Common exteroceptive sensors are

Electromagnetic spectrum

Sound

Touch

Smell, odor

Temperature

Range to things in the environment

Attitude (Inclination)

Some robotic lawn mowers will adapt their programming by detecting the speed in which grass grows as needed to maintain a perfect cut lawn, and some vacuum cleaning robots have dirt detectors that sense how much dirt is being picked up and use this information to tell them to stay in one area longer.

[edit] Task performance

The next step in autonomous behavior is to actually perform a physical task. A new area showing commercial promise is domestic robots, with a flood of small vacuuming robots beginning with iRobot and Electrolux in 2002. While the level of intelligence is not high in these systems, they navigate over wide areas and pilot in tight situations around homes using contact and non-contact sensors. Both of these robots use proprietary algorithms to increase coverage over simple random bounce. Similarly, the Friendly Robotics or Lawnbott lawn mower uses an RF perimeter wire, like a dog fence, as a virtual version of bump sensing. However, the Friendly Robotics mower uses sophisticated tiling algorithms to calculate the most effective pattern for cutting the entire lawn. Lawnbott mowers rely on a combination of random and smart spiraling patterns. Smart spiraling either starts randomly, or when the robot senses high grass patches.

The next level of autonomous task performance requires a robot to perform conditional tasks. For instance, MobileRobots' security robot can be programmed to detect intruders and respond in a particular way depending upon where the intruder is.

[edit] Indoor position sensing and navigation

For a robot to associate behaviors with a place (localization) requires it to know where it is and to be able to navigate point-to-point. Such navigation began with wire-guidance in the 1970s and progressed in the early 2000s to beacon-based triangulation. Current commercial robots autonomously navigate based on sensing natural features. The first commercial robots to achieve this were Pyxus' HelpMate hospital robot and the CyberMotion guard robot, both designed by robotics pioneers in the 1980s. These robots originally used manually created CAD floor plans, sonar sensing and wall-following variations to navigate buildings. The next generation, such as MobileRobots' PatrolBot and autonomous wheelchair, both introduced in 2004, have the ability to create their own laser-based maps of a building and to navigate open areas as well as corridors. Their control system changes its path on-the-fly if something blocks the way. Add the ability to control elevators and electronic doors, as Swisslog's and many other indoor bots do, and now robots can now freely navigate entire buildings. Autonomous stair-climbing, however, has not yet been achieved by any commercial bot.

As these indoor techniques continue to develop, vacuuming robots will gain the ability to clean a specific user specified room or a whole floor. Security robots will be able to cooperatively surround intruders and cut off exits. These advances also bring concommitant protections: robots' internal maps typically permit "forbidden areas" to be defined to prevent robots from autonomously entering certain regions.

[edit] Outdoor autonomous position-sensing and navigation

Outdoor autonomy is most easily achieved in the air, since obstacles are rare. Cruise missiles are rather dangerous highly autonomous robots. Pilotless drone aircraft are increasingly used for reconnaissance. Some of these unmanned aerial vehicles (UAVs) are capable of flying their entire mission without any human interaction at all except possibly for the landing where a person intervenes using radio remote control. But some drone aircraft are capable of a safe, automatic landing also.

Outdoor autonomy is the most difficult for ground vehicles, due to: a) 3-dimensional terrain; b) great disparities in surface density; c) weather exigencies and d) instability of the sensed environment.

In the US, the MDARS project, which defined and built a prototype outdoor surveillance robot in the 1990s, is now moving into production and will be implemented in 2006. This robot can navigate semi-autonomously and detect intruders, using the MRHA software architecture planned for all unmanned military vehicles. MobileRobots.com will be producing its first outdoor surveillance robot for commercial use during the same year.

The Mars rovers MER-A and MER-B can find the position of the sun and navigate their own routes to destinations on the fly by:

mapping the surface with 3-D vision
computing safe and unsafe areas on the surface within that field of vision
computing optimal paths across the safe area towards the desired destination
driving along the calculated route;
repeating this cycle until either the destination is reached, or there is no known path to the destination

The DARPA Grand Challenge is an attempt to encourage development of even more autonomous capabilities for ground vehicles, while this has been the demonstrated goal for aerial robots since 1990 as part of the AUVSI International Aerial Robotics Competition.