eases remote robot control
Chhavi Sachdev ,
Technology Research News
Remember when every kid had a remote control
car, and sometimes parents did, too? Running around the house chasing
a tiny car and jamming the joystick controls was a part of growing up.
It seems that technology has grown up as well.
A team of researchers at Carnegie Mellon University and the Swiss Federal
Institute of Technology at Lausanne has developed software that allows
people to control the movement of a robot
by using a computer or Personal Digital Assistant (PDA) and the Internet.
The set up allows for remote control of a robot from anywhere in the world.
It’s not just a game, though. “Our work is inspired by a wide range of
remote vehicle applications, particularly military reconnaissance and
planetary exploration,” said Terrence Fong, a research assistant at the
Robotics Institute at Carnegie Mellon University. The tools enable a user
to understand the remote environment and control the remote vehicle better,
Traditionally, even experts have found it difficult to remotely drive
robots. The teleoperation tools make driving mobile robots easier because
the user and the remote vehicle share control, said Fong. “Our work is
centered on a concept called collaborative control, in which the human
and the robot engage in dialogue,” said Fong.
Operating remote vehicles using these techniques requires no special training,
The human and the remote robot exchange questions and information, so
the robot can decide how to use human advice, following it when it is
forthcoming and relevant, and modifying it when the advice is unsafe or
inappropriate, he said.
They aren’t talking about a sentient HAL-esque being; the robot still
follows a higher-level strategy set by the human. Still, the robot has
more freedom in execution, which makes it able to function even when the
human operator is unavailable or distracted, according to Fong. This makes
the system more dependable, he said.
The PC version of the teleoperation system is dubbed WebDriver and the
PDA version, PdaDriver. Both versions are designed to minimize network
bandwidth usage. The systems function “even with low-bandwidth, high-delay
networks,” said Fong. Both interfaces combine several types of sensory
input to give the human operator a composite picture of the robot’s environment.
The system’s input devices, which include a laser scanner, monochrome
video camera, stereovision sensor, ultrasonic sonar, and an odometer,
complement each other. For example, if the robot is standing directly
in front of a smooth, untextured wall with a large plant close by, each
sensor will miss something from the scene. With the sonar detecting the
plant, the laser scanner following the wall, and stereo vision finding
the wall's edge, the sensors take in the whole scene.
The Web version is a Java applet that allows the user to see the status
of all five sensors and give the robot specific commands in several different
ways. Instead of live video, the image server senses images only when
something significant happens, such as if an obstacle appears, said Fong.
It has two primary modes: dynamic map, which shows radar and sonar inputs,
and an image manager, which displays and stores data from the pan/tilt
camera mounted on the front of the robot. Both modes allow a user to send
commands, receive feedback and control the robot’s camera. In image manager
mode, the user drives the robot by clicking a series of waypoints and
then pressing Go.
A user can also control the robot manually by telling it to, for instance,
move forward 5 meters or turn right at 10 degrees per second. The user
can do this in situations in which waypoint driving does not work, said
Fong. The Web application also supports touchscreen controls, which could
allow people to remotely control robots from devices in kiosks, Fong said.
The PDA version has four control modes: command, sensors, video, and map.
In command mode a user controls relative position and motion of the robot
by clicking on the display’s vertical or horizontal axis. In sensors mode,
the user can directly control the robot’s on-board sensors to pan, tilt,
and zoom the robot’s camera, enable and disable sonars, and activate motion
detection triggers, according to Fong.
Video mode displays images from a robot-mounted camera and map mode displays
a sonar map from both robot and global frames of reference. The video
and map modes also allow a user to control the robot's movement using
PdaDriver is an improved version of WebDriver, said Fong. “PdaDriver allows
the user to specify a path... PdaDriver also supports collaborative control,
so that the robot can ask questions of the human, [such as,] ‘I seem to
be stuck, can you help?’” said Fong.
The researchers are also working on a remote driving system, GestureDriver,
which can be used without keyboard or joystick-based interfaces, said
Fong. Putting the vision system on the robot allows a user to have a direct
visual interaction with the robot, controlling it by hand gestures such
as pointing an arm to where the robot should go, he said.
“Hand motions are converted to remote driving commands,” said Fong. A
computer vision system tracks the gestures and classifies them using a
geometric model that maps the gestures to specific motion commands for
the robot, according to Fong.
The researchers concede, however, that visual gestures are not the easiest
way to command the robots. Testers reported that it is fatiguing, according
They have also been working on a “drive-by-feel interface,” called HapticDriver,
which is hand controlled, said Fong. In this system, a “haptic device
and robot sensors allow a user to feel the environment, thus avoiding
collisions and enabling precision driving” and movements such as docking,
The systems could eventually be used by geologists and astronomers to
explore and retrieve samples from remote locations on earth and other
planets, Fong said.
“The sensor fusion part is the most sophisticated and interesting,” piece
of the research, said Paul Backes, Technical Group leader at NASA’s Jet
Propulsion Laboratory. “The paper is a worthwhile collection of the concepts
…each of the concepts they discuss seem realistic and valid for some applications,”
Fong's colleagues were Sébastien Grange and Charles Baur of the Swiss
Federal Institute of Technology at Laussane, and Charles Thorpe at Carnegie
Mellon University. They published the research in the July 2001 issue
of Autonomous Robots. The research was funded by the Defense Advanced
Research Projects Agency (DARPA), the National Science
Foundation (NSF), and Science Applications International Corporation (SAIC,
Timeline: 2-3 years
Funding: Corporate; Government
TRN Categories: Robotics; Human-Computer Interaction
Story Type: News
Related Elements: Technical paper, "Advanced Interfaces
for Vehicle Teleoperation: Collaborative Control, Sensor Fusion Displays,
And Remote Driving Tools," Autonomous Robots, July 2001.
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