Autonomous research robot
Encyclopedia
The Denning Mobile Robot company of Boston was the first to offer ready-made autonomous robot
s, which were purchased primarily by researchers. Grinnell More's Real World Interface, Inc. (RWI) and James Slater's Nomadic Technologies in the US and Francesco Mondada's K-Team in Switzerland were also among the pioneers to address the need for ready-made robots for robotics researchers with the B-21 from RWI, XR4000 from Nomadic and tiny Khepera mobile robot from K-Team; however, their prices meant that only a few graduate students and military researchers could afford them. The low-cost Pioneer robot was introduced by a collaboration between RWI and ActivMedia Robotics
in 1995, making robots available to many and opening the floodgates to new research in mobile robotics.
By 1999, the Denning company was defunct. In 1998, RWI joined with ISRobotics to form the iRobot
corporation. There Grinnell More introduced the PackBot
remote control robot, veering away from autonomous development and research robots to pursue military venues. Nomadic Technologies also left the field. MobileRobots Inc and K-Team continued to build on autonomy and provide for the research community.
In 2003 the Defense Advanced Research Projects Agency (DARPA) contracted with Segway
to convert fifteen Segway PT
s into Segway Robotic Mobility Platforms. Segway developed the platform to serve as a reliable, cost-effective tool for research institutions and delivered the units to DARPA in April. In June 2003 DARPA worked with SPAWAR Systems Center San Diego to distribute the units to 14 government and university research institutions to use in robotic research projects.
Research robots made great strides in autonomous indoor navigation between the 1990s and the 2000s. Currently, a number of ready-made research bases have the sensing, mobility, and computational power necessary for such autonomy: The Pioneer, PatrolBot
, PowerBot, and PeopleBot platforms can map buildings and navigate out-of-the-box, using SLAM
and a variation on Monte Carlo method
/Markov localization and modified value-iterated search navigation techniques, with any sensor of the 2-D range-finder class. This method creates a human readable map of the robot's workspace that can be used to control and track robots of this type as they move. Evolution Robotics
offers single-camera VSLAM software, which replaces range-finding
with visual pattern-matching
, but this system cannot create a human readable map with which to monitor robots' position. Other groups are building stereocam-based VSLAM. Because the stereocam provides range-finding data using the disparity between the lenses, maps can be made and robots tracked. The K-Team Khepera
, Segway-based platforms and other research robots can link to external computing resources to use such software.
The precision of any of these methods depends upon the precision of the sensor, the granularity of data tracked and the speed of calculation. Range-finding lasers may have +/-1 cm accuracy while digital stereocamera accuracy is limited to a quarter pixel and thus is highly range-dependent. Vision-based systems require more computational resources than simple range-finding systems such as lasers, but may do the computation on a digital signal processor embedded with the camera. Because of cost and precision trade-offs, less expensive vision-based systems tend to be used on consumer robots while commercial and industrial robot
s and automated guided vehicle
s (AGVs) tend to use laser-based systems.
Outdoors, localization is primarily handled with GPS, however, satellite signals can frequently be lost due to weather, trees, buildings or other obstructions. When the signal is lost, the robot typically navigates using dead reckoning
and inertial motion tracking. Dead reckoning relies on relative wheel motion and is highly subject to cumulative slippage errors. Inertial motion tracking uses rate gyro
scopes and accelerometer
s to determine actual motion of the platform. The accuracy of inertial motion tracking depends upon the quality and calibration of the sensor
s employed. The Segway RMP 400 and Seekur robots are two of the few research platforms designed for such research; most other outdoor research robots are jerry-rigged by researchers from existing vehicles.
In constrained areas, some robots, such as the John Deere Gator, simply surround the perimeter with radio beacons and use simple triangulation
from three or more beacons to localize and navigate. Beacons are also used indoors by older AGVs in factories.
Autonomous Solutions is a leader in the field of outdoor navigation software; their system is used by John Deere tractors and by some military platforms.
or Open Source Software, including Carmen
from Carnegie Mellon, Player/Stage/Gazebo from the University of Southern California
and the ARIA API libraries from MobileRobots Inc. There is also commercial software: Webots
has been continuously developed since 1998 and is currently used by more than 500 universities. It runs on Linux, Windows and Mac OS X. More recently, in June 2006, Microsoft Research
began offering free beta-test copies of a Robotics Studio software development kit with Pioneer robots in simulation for Windows XP
in an attempt to counter Linux dominance onboard mobile robot
platforms. An older platform: URBI
with a Free Software SDK is used in many universities. The plethora of autonomous mobile robots and software available for researchers has greatly sped the pace of development in the robotics
field.
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...
s, which were purchased primarily by researchers. Grinnell More's Real World Interface, Inc. (RWI) and James Slater's Nomadic Technologies in the US and Francesco Mondada's K-Team in Switzerland were also among the pioneers to address the need for ready-made robots for robotics researchers with the B-21 from RWI, XR4000 from Nomadic and tiny Khepera mobile robot from K-Team; however, their prices meant that only a few graduate students and military researchers could afford them. The low-cost Pioneer robot was introduced by a collaboration between RWI and ActivMedia Robotics
ActivMedia Robotics
ActivMedia Robotics, former name of MobileRobots Inc, is a company in Amherst, New Hampshire that designs and manufactures autonomous robots, commercial service robots, robot software and navigation systems for robot developers and manufacturers....
in 1995, making robots available to many and opening the floodgates to new research in mobile robotics.
By 1999, the Denning company was defunct. In 1998, RWI joined with ISRobotics to form the iRobot
IRobot
iRobot Corporation is an American advanced technology company founded in 1990 and incorporated in Delaware in 2000, the iRobot Corporation designs robots such as an autonomous home vacuum cleaner , the Scooba that scrubs and cleans hard floors, and military and police robots, such as the PackBot...
corporation. There Grinnell More introduced the PackBot
PackBot
PackBot is a series of military robots by iRobot. More than 2000 PackBots are currently on station in Iraq and Afghanistan, with hundreds more on the way.-Current PackBot 510 variants:...
remote control robot, veering away from autonomous development and research robots to pursue military venues. Nomadic Technologies also left the field. MobileRobots Inc and K-Team continued to build on autonomy and provide for the research community.
In 2003 the Defense Advanced Research Projects Agency (DARPA) contracted with Segway
Segway Inc.
Segway Inc. of New Hampshire, USA is the manufacturer of a two-wheeled, self-balancing electric vehicle, the Segway PT, invented by Dean Kamen...
to convert fifteen Segway PT
Segway PT
The Segway PT is a two-wheeled, self-balancing transportation machine invented by Dean Kamen. It is produced by Segway Inc. of New Hampshire, USA. The name "Segway" is a homophone of "segue" while "PT" denotes personal transporter....
s into Segway Robotic Mobility Platforms. Segway developed the platform to serve as a reliable, cost-effective tool for research institutions and delivered the units to DARPA in April. In June 2003 DARPA worked with SPAWAR Systems Center San Diego to distribute the units to 14 government and university research institutions to use in robotic research projects.
Autonomous navigation techniques
PatrolBot
PatrolBot is a programmable autonomous general purpose service robot rover built by MobileRobots Inc. PatrolBots are manufactured in various configurations and serve as bases for companies developing delivery robots, security robots, environmental monitoring rovers, robot guides and other indoor...
, PowerBot, and PeopleBot platforms can map buildings and navigate out-of-the-box, using SLAM
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...
and a variation on Monte Carlo method
Monte Carlo method
Monte Carlo methods are a class of computational algorithms that rely on repeated random sampling to compute their results. Monte Carlo methods are often used in computer simulations of physical and mathematical systems...
/Markov localization and modified value-iterated search navigation techniques, with any sensor of the 2-D range-finder class. This method creates a human readable map of the robot's workspace that can be used to control and track robots of this type as they move. Evolution Robotics
Evolution robotics
Evolution Robotics is an American company specializing in robotics technologies from Pasadena, California. The product range covers computer vision, localization and autonomous navigation....
offers single-camera VSLAM software, which replaces range-finding
Rangefinder
A rangefinder is a device that measures distance from the observer to a target, for the purposes of surveying, determining focus in photography, or accurately aiming a weapon. Some devices use active methods to measure ; others measure distance using trigonometry...
with visual pattern-matching
Pattern matching
In computer science, pattern matching is the act of checking some sequence of tokens for the presence of the constituents of some pattern. In contrast to pattern recognition, the match usually has to be exact. The patterns generally have the form of either sequences or tree structures...
, but this system cannot create a human readable map with which to monitor robots' position. Other groups are building stereocam-based VSLAM. Because the stereocam provides range-finding data using the disparity between the lenses, maps can be made and robots tracked. The K-Team Khepera
Khepera mobile robot
The Khepera is a small differential wheeled mobile robot that was developed at the LAMI laboratory of Prof. Jean-Daniel Nicoud at EPFL in the mid '90s. It was developed by Edo...
, Segway-based platforms and other research robots can link to external computing resources to use such software.
The precision of any of these methods depends upon the precision of the sensor, the granularity of data tracked and the speed of calculation. Range-finding lasers may have +/-1 cm accuracy while digital stereocamera accuracy is limited to a quarter pixel and thus is highly range-dependent. Vision-based systems require more computational resources than simple range-finding systems such as lasers, but may do the computation on a digital signal processor embedded with the camera. Because of cost and precision trade-offs, less expensive vision-based systems tend to be used on consumer robots while commercial and industrial robot
Industrial robot
An industrial robot is defined by ISO as an automatically controlled, reprogrammable, multipurpose manipulator programmable in three or more axes...
s and automated guided vehicle
Automated Guided Vehicle
An automated guided vehicle or automatic guided vehicle is a mobile robot that follows markers or wires in the floor, or uses vision or lasers. They are most often used in industrial applications to move materials around a manufacturing facility or a warehouse...
s (AGVs) tend to use laser-based systems.
Outdoors, localization is primarily handled with GPS, however, satellite signals can frequently be lost due to weather, trees, buildings or other obstructions. When the signal is lost, the robot typically navigates using 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...
and inertial motion tracking. Dead reckoning relies on relative wheel motion and is highly subject to cumulative slippage errors. Inertial motion tracking uses rate gyro
Rate gyro
A rate gyro is a type of gyroscope, which rather than indicating direction, indicates the rate of change of angle with time. If a gyro has only one gimbal ring, with consequently only two planes of freedom, it can be adapted for use as a rate gyro to measure a rate of angular movement.Rate gyros...
scopes and accelerometer
Accelerometer
An accelerometer is a device that measures proper acceleration, also called the four-acceleration. This is not necessarily the same as the coordinate acceleration , but is rather the type of acceleration associated with the phenomenon of weight experienced by a test mass that resides in the frame...
s to determine actual motion of the platform. The accuracy of inertial motion tracking depends upon the quality and calibration of the sensor
Sensor
A sensor is a device that measures a physical quantity and converts it into a signal which can be read by an observer or by an instrument. For example, a mercury-in-glass thermometer converts the measured temperature into expansion and contraction of a liquid which can be read on a calibrated...
s employed. The Segway RMP 400 and Seekur robots are two of the few research platforms designed for such research; most other outdoor research robots are jerry-rigged by researchers from existing vehicles.
In constrained areas, some robots, such as the John Deere Gator, simply surround the perimeter with radio beacons and use simple triangulation
Triangulation
In trigonometry and geometry, triangulation is the process of determining the location of a point by measuring angles to it from known points at either end of a fixed baseline, rather than measuring distances to the point directly...
from three or more beacons to localize and navigate. Beacons are also used indoors by older AGVs in factories.
Autonomous Solutions is a leader in the field of outdoor navigation software; their system is used by John Deere tractors and by some military platforms.
Programming research robots
Much research software for autonomous robots is Free SoftwareFree software
Free software, software libre or libre software is software that can be used, studied, and modified without restriction, and which can be copied and redistributed in modified or unmodified form either without restriction, or with restrictions that only ensure that further recipients can also do...
or Open Source Software, including Carmen
Carmen Toolkit
CARMEN, the Carnegie Mellon Robot Navigation Toolkit, is an open-source collection of software for mobile robot control. It is designed as a modular software to provide basic navigation functionalities, which include: base and sensor control, logging, obstacle avoidance, localization, path...
from Carnegie Mellon, Player/Stage/Gazebo from the University of Southern California
University of Southern California
The University of Southern California is a private, not-for-profit, nonsectarian, research university located in Los Angeles, California, United States. USC was founded in 1880, making it California's oldest private research university...
and the ARIA API libraries from MobileRobots Inc. There is also commercial software: Webots
Webots
Webots is a professional robot simulator widely used for educational purposes.The Webots project started in 1996, initially developed by Dr. Olivier Michel at the Swiss Federal Institute of Technology in Lausanne, Switzerland....
has been continuously developed since 1998 and is currently used by more than 500 universities. It runs on Linux, Windows and Mac OS X. More recently, in June 2006, Microsoft Research
Microsoft Research
Microsoft Research is the research division of Microsoft created in 1991 for developing various computer science ideas and integrating them into Microsoft products. It currently employs Turing Award winners C.A.R. Hoare, Butler Lampson, and Charles P...
began offering free beta-test copies of a Robotics Studio software development kit with Pioneer robots in simulation for Windows XP
Windows XP
Windows XP is an operating system produced by Microsoft for use on personal computers, including home and business desktops, laptops and media centers. First released to computer manufacturers on August 24, 2001, it is the second most popular version of Windows, based on installed user base...
in an attempt to counter Linux dominance onboard mobile robot
Mobile robot
A mobile robot is an automatic machine that is capable of movement in a given environment.-Overview:Mobile robots have the capability to move around in their environment and are not fixed to one physical location...
platforms. An older platform: URBI
URBI
Urbi is an open source cross-platform software platform in C++ used to develop applications for robotics and complex systems. Urbi is based on the UObject distributed C++ component architecture. It also includes the urbiscript orchestration language which is a parallel and event-driven script...
with a Free Software SDK is used in many universities. The plethora of autonomous mobile robots and software available for researchers has greatly sped the pace of development in the robotics
Robotics
Robotics is the branch of technology that deals with the design, construction, operation, structural disposition, manufacture and application of robots...
field.