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Introduction to Robotics
In practical usage, a Robot is a mechanical device which performs automated physical tasks, either according to direct human supervision, a pre-defined program, or a set of general guidelines using artificial intelligence techniques. Robots are typically used to do the tasks that are too dirty, dangerous, difficult, repetitive or dull for humans. This usually takes the form of industrial robots used in manufacturing lines. Other applications include toxic waste cleanup, underwater and space exploration, mining, search and rescue, and mine finding. Recently however, robots are finding their way into the consumer market with uses in entertainment, vacuum cleaning, and lawn mowing. A robot may include a feedback-driven connection between sense and action, not under direct human control, although it may have a human override function. The action may take the form of electro-magnetic motors or actuators (also called effectors) that move an arm, open and close grips, or propel the robot. The step by step control and feedback is provided by a computer program run on either an external or embedded computer or a microcontroller. By this definition, a robot may include nearly all automated devices.
Ask a number of people to describe a robot and most of them will answer they look like a human. Interestingly a robot that looks like a human is probably the most difficult robot to make. It is usually a waste of time and not the most sensible thing to model a robot after a human being. A robot needs to be above all functional and designed with qualities that suit its primary tasks. It depends on the task at hand whether the robot is big, small, is able to move or nailed to the ground. Each and every task means different qualities, form and function; a robot needs to be designed with the task in mind.
Mobile Robots
Fig 1.Mars Explorer image Mobile robots are able to move, usually they perform task such as search areas. A prime example is the Mars Explorer, specifically designed to roam the mars surface.
Mobile robots are a great help to such collapsed building for survivors Mobile robots are used for task where people cannot go. Either because it is too dangerous of because people cannot reach the area that needs to be searched.
Mobile robots can be divided in two categories:
Rolling Robots: Rolling robots have wheels to move around. These are the type of robots that can quickly and easily search move around. However they are only useful in flat areas, rocky terrains give them a hard time. Flat terrains are their territory.
Fig 2.. rolling robots
Walking Robots: Robots on legs are usually brought in when the terrain is rocky and difficult to enter with wheels. Robots have a hard time shifting balance and keep them from tumbling. That’s why most robots with have at least 4 of them, usually they have 6 legs or more. Even when they lift one or more legs they still keep their balance. Development of legged robots is often modeled after insects or crawfish..
Fig 3..
Stationary Robots
Robots are not only used to explore areas or imitate a human being. Most robots perform repeating tasks without ever moving an inch. Most robots are ‘working’ in industry settings. Especially dull and repeating tasks are suitable for robots. A robot never grows tired, it will perform its duty day and night without ever complaining. In case the tasks at hand are done, the robots will be reprogrammed to perform other tasks.
Fig 4.
Autonomous Robots
Fig 5..
Autonomous robots are self supporting or in other words self contained. In a way they rely on their own ‘brains’.
Autonomous robots run a program that give them the opportunity to decide on the action to perform depending on their surroundings. At times these robots even learn new behavior. They start out with a short routine and adapt this routine to be more successful at the task they perform. The most successful routine will be repeated as such their behavior is shaped. Autonomous robots can learn to walk or avoid obstacles they find in their way. Think about a six legged robot, at first the legs move ad random, after a little while the robot adjust its program and performs a pattern which enables it to move in a direction.
Remote-control Robots
An autonomous robot is despite its autonomous not a very clever or intelligent unit. The memory and brain capacity is usually limited. An autonomous robot can be compared to an insect in that respect.
In case a robot needs to perform more complicated yet undetermined tasks an autonomous robot is not the right choice.
Complicated tasks are still best performed by human beings with real brainpower. A person can guide a robot by remote control. A person can perform difficult and usually dangerous tasks without being at the spot where the tasks are performed. To detonate a bomb it is safer to send the robot to the danger area.
Fig 6.Dante 2, a NASA robot designed to explore volcanoes via remote control.

Virtual Robots
Virtual robots don’t exits in real life. Virtual robots are just programs, building blocks of software inside a computer. A virtual robot can simulate a real robot or just perform a repeating task. A special kind of robot is a robot that searches the world wide web. The internet has countless robots crawling from site to site. These WebCrawler’s collect information on websites and send this information to the search engines.
Another popular virtual robot is the chatterbot. These robots simulate conversations with users of the internet. One of the first chatterbots was ELIZA. There are many varieties of chatter bots now, including E.L.V.I.S.
BEAM Robots
BEAM is short for Biology, Electronics, Aesthetics and Mechanics. BEAM robots are made by hobbyists. BEAM robots can be simple and very suitable for starters.
Fig 7.
Biology
Robots are often modeled after nature. A lot of BEAM robots look remarkably like insects. Insects are easy to build in mechanical form. Not just the mechanics are in inspiration also the limited behavior can easily be programmed in a limited amount of memory and processing power.
Two basic ways of using effectors are to move the robot around (locomotion) or to move other objects around (manipulation). This distinction divides robotics into two mostly separate categories: mobile robotics (moving) and manipulator robotics (grabbing).
Joints connect parts of manipulators. The most common joint types are:
1. rotary (rotation around a fixed axis)
2. prismatic (linear movement)
A parallel robot is one whose arms (primary axes) have three concurrent prismatic joints or both prismatic and rotary joints. Degrees of freedom (DOF) means axes of movement. The human arm has seven Degrees of Freedom. A "6 DOF" arm is highly flexible.
Proprioceptive sensors sense the robot's actuators (e.g., shaft encoders, joint angle sensors). Proprioception is one of the most important senses of the human body.
Alternately, robot has been used as the general term for a mechanical man, or an automaton resembling an animal, either real or imaginary. It has come to be applied to many machines which directly replace a human or animal in work or play. In this way, a robot can be seen as a form of biomimicry. Lack of anthropomorphism is perhaps what makes us reluctant to refer to the highly complex modern washer-dryer as a robot. However, in modern understanding, the term implies a degree of autonomy that would exclude many automatic machine tools from being called robots. It is the search for ever more highly autonomous robots which is the major focus of robotics research and which drives much work in artificial intelligence.
The term robot is also often used to refer to sophisticated mechanical devices that are remotely controlled by human beings, such as waldoes and ROVs. .