Robotic mapping - AbsoluteAstronomy.com

Robotic mapping is related to cartography

Cartography

Cartography is the study and practice of making maps. Combining science, aesthetics, and technique, cartography builds on the premise that reality can be modeled in ways that communicate spatial information effectively.The fundamental problems of traditional cartography are to:*Set the map's...

. The goal for an autonomous robot

Autonomous robot

Autonomous robots are robots that 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...

to be able to construct (or use ) a map or floor plan

Floor plan

In architecture and building engineering, a floor plan, or floorplan, is a diagram, usually to scale, showing a view from above of the relationships between rooms, spaces and other physical features at one level of a structure....

and to localize itself in it. Robotic mapping is that branch of one, which deals with the study and application of ability to construct map or floor plan by the autonomous robot and to localize itself in it.

Evolutionarily shaped blind action may suffice to keep some animals alive. For some insect

Insect

Insects are a class of living creatures within the arthropods that have a chitinous exoskeleton, a three-part body , three pairs of jointed legs, compound eyes, and two antennae...

s for example, the environment is not interpreted as a map, and they survive only with a triggered response. A slightly more elaborated navigation strategy dramatically enhances the capabilities of the robot. Cognitive map

Cognitive map

Cognitive maps are a type of mental processing composed of a series of psychological transformations by which an individual can acquire, code, store, recall, and decode information about the relative locations and attributes of phenomena in their everyday or metaphorical spatial environment.The...

s enable planning capacities, and use of current perceptions, memorized events, and expected consequences.

Sources

The robot has two sources of information: the idiothetic

Idiothetic

Idiothetic literally means "self-proposition" , and is used in navigation models as in the phrase "idiothetic cues" to indicate that path integration was used to determine the present location instead of allothetic, or external, cues...

and the allothetic

Allothetic

Allothetic means being centred in people or places other than oneself, and is used in navigation models as in the phrase "allothetic map" to indicate that a global map, not orientated or centred on the subject was used, rather than idiothetic, which means a navigation system centred on the...

sources. When in motion, a robot can use dead reckoning

Dead reckoning

In navigation, dead reckoning is the process of calculating one's current position by using a previously determined position, or fix, and advancing that position based upon known or estimated speeds over elapsed time, and course...

methods such as tracking the number of revolutions of its wheels; this corresponds to the idiothetic

Idiothetic

source and can give the absolute position of the robot, but it is subject to cumulative error which can grow quickly.

The allothetic

Allothetic

source corresponds to the sensors of the robot, like a camera, a microphone, laser

Laser

A laser is a device that emits light through a process of optical amplification based on the stimulated emission of photons. The term "laser" originated as an acronym for Light Amplification by Stimulated Emission of Radiation...

or sonar

Sonar

Sonar is a technique that uses sound propagation to navigate, communicate with or detect other vessels...

. The problem here is "perceptual aliasing". This means that two different places can be perceived as the same. For example, in a building, it may be impossible for to determine your location solely with the visual information, because all the corridors may look the same.

Map representation

The internal representation of the map can be "metric" or "topological":

The metric framework is the most common for humans and considers a two dimensional space in which it places the objects. The objects are placed with precise coordinates. This representation is very useful, but is sensitive to noise and it is difficult to calculate the distances precisely.
The topological framework only considers places and relations between them. Often, the distances between places are stored. The map is then a graph
Graph (mathematics)
In mathematics, a graph is an abstract representation of a set of objects where some pairs of the objects are connected by links. The interconnected objects are represented by mathematical abstractions called vertices, and the links that connect some pairs of vertices are called edges...

, in which the nodes corresponds to places and arcs correspond to the paths.

Many techniques use probabilistic representations of the map, in order to handle uncertainty.

There are three main methods of map representations, i.e., free space maps, object maps, and composite maps. These employ the notion of a grid, but permit the resolution of the grid to vary so that it can become finer where more accuracy is needed and more coarse where the map is uniform.

Map learning

Map-learning cannot be separated from the localization process, and a difficulty arises when errors in localization are incorporated into the map. This problem is commonly referred to as Simultaneous localization and mapping

Simultaneous localization and mapping

Simultaneous localization and mapping is a technique used by robots and autonomous vehicles to build up a map within an unknown environment , or to update a map within a known environment , while at the same time keeping track of their current location.- Operational definition :Maps are used...

(SLAM).

An important additional problem is to determine whether the robot is in a part of environment already stored or never visited. One way to solve this problem is by using electric beacon

Electric beacon

Electric beacons are a kind of beacon used with direction finding equipment to find ones relative bearing to a known location .The term electric beacon includes radio, infrared and sonar beacons.- Radio beacons :...

Path planning

Motion planning

Motion planning is a term used in robotics for the process of detailing a task into discrete motions....

is an important issue as it allows a robot to get from point A to point B. Path planning algorithms are measured by their computational complexity. The feasibility of real-time motion planning is dependent on the accuracy of the map (or floorplan), on robot localization and on the number of obstacles. Topologically, the problem of path planning is related to the shortest path problem

Shortest path problem

In graph theory, the shortest path problem is the problem of finding a path between two vertices in a graph such that the sum of the weights of its constituent edges is minimized...

problem of finding a route between two nodes in a graph

Graph (mathematics)

In mathematics, a graph is an abstract representation of a set of objects where some pairs of the objects are connected by links. The interconnected objects are represented by mathematical abstractions called vertices, and the links that connect some pairs of vertices are called edges...

Robot navigation

Outdoor robots can use GPS in a similar way to automotive navigation system

Automotive navigation system

An automotive navigation system is a satellite navigation system designed for use in automobiles. It typically uses a GPS navigation device to acquire position data to locate the user on a road in the unit's map database. Using the road database, the unit can give directions to other locations...

s. Alternative systems can be used with floor plan

Floor plan

instead of map

Map

A map is a visual representation of an area—a symbolic depiction highlighting relationships between elements of that space such as objects, regions, and themes....

s for indoor robots, combined with localization wireless hardware. Electric beacon