Mobile Robot

Posted on

Overview

Mobile robots have the capability to move around in their environment and are not fixed to one physical location. In contrast, industrial robots usually consist of a jointed arm (multi-linked manipulator) and gripper assembly (or end effector) that is attached to a fixed surface.
Mobile Robot Parts
Mobile robots are the focus of a great deal of current research and almost every major university has one or more labs that focus on mobile robot research. Mobile robots are also found in industry, military and security environments. They also appear as consumer products, for entertainment or to perform certain tasks like vacuum cleaning or mowing.

Classification

Mobile robots may be classified by:

The environment in which they travel:

  • Land or home robots. They are most commonly wheeled, but also include legged robots with two or more legs (humanoid, or resembling animals or insects).
  • Aerial robots are usually referred to as unmanned aerial vehicles (UAVs)
  • Underwater robots are usually called autonomous underwater vehicles (AUVs)

The device they use to move, mainly:

  • Legged robot : human-like legs (i.e. an android) or animal-like legs.
  • Wheeled robot.
  • Tracks.

Mobile Robot Navigation

There are many types of mobile robot navigation:
Tracking Robot
Manual Remote or Tele-op

A manually tele-op’d robot is totally under control of a driver with a joystick or other control device. The device may be plugged directly into the robot, may be a wireless joystick, or may be an accessory to a wireless computer or other controller. A tele-op’d robot is typically used to keep the operator out of harm’s way. Examples of manual remote robots include Foster-Miller’s Talon and iRobot’s PackBot.

Guarded Tele-op

A guarded tele-op robot has the ability to sense and avoid obstacles but will otherwise navigate as driven, like a robot under manual tele-op. Few if any mobile robots offer only guarded tele-op. {See Sliding Autonomy below.)

Line-following Robot

Some of the earliest Automated Guided Vehicles (AGVs) were line following mobile robots. They might follow a visual line painted or embedded in the floor or ceiling or an electrical wire in the floor. Most of these robots operated a simple “keep the line in the center sensor” algorithm. They could not circumnavigate obstacles; they just stopped and waited when something blocked their path. Many examples of such vehicles are still sold, by FMC, Egemin, HK Systems and many other companies.

Autonomously Randomized Robot

Autonomous robots with random motion basically bounce off walls, whether those walls are sensed with physical bumpers like the Roomba cleaners or with electronic sensors like the Friendly Robotics lawn mower. The simple algorithm of bump and turn 30 degrees leads eventually to coverage of most or all of a floor or yard surface.

Autonomously Guided Robot

An autonomously guided robot knows at least some information about where it is and plans its path to various goals and or waypoints along the way. It can gather sensor readings that are time- and location-stamped, so that a hospital, for instance, can know exactly when and where radiation levels exceeded permissible levels. Such robots are often part of the wireless enterprise network, interfaced with other sensing and control systems in the building. For instance, the PatrolBot security robot responds to alarms, operates elevators and notifies the command center an incident arises. Other autonomously guided robots include the SpeciMinder and the Tug delivery robots for hospital labs.

Sliding Autonomy

More capable robots combine multiple levels of navigation under a system called sliding autonomy. Most autonomously guided robots, such as the HelpMate hospital robot, also offer a manual mode. The ARCSinside control system, which is used in the ADAM, PatrolBot, Speci-Minder, MapperBot and a number of other robots, offers full sliding autonomy, from manual to guarded to autonomous modes.

2 thoughts on “Mobile Robot

  1. Pingback: Mobile Robot

Leave a Reply

Your email address will not be published. Required fields are marked *