BASICS OF ROBOTICS
The term robot comes from the Czech word robota,generally translated as forced labor.On the major basic level, human beings are made up of five major components.A body structure ,a muscle system to move the body structure. A sensory system that receives information about the body and the surroundings environment.A power source to activate the muscles and sensors.A brain system that processes sensory information and tells the muscles what to do.A typical robot has a movable physical structure,a motor of some sort ,a sensor system,a power supply and a computer “brain” that controls all of these elements.Joseph engelberger,a pioneer in industrial robotics ,once remarked “I cant defined a robot , but I know one when I see one.”Like wise we all will have a definition on robots.The vast majority of robots do have several qualities in common .First of all,almost all robots have a movable body.Like the bones in your body ,the individual segments are connected together with joints.
Robots spin wheels and pivot jointed segments with some sort of actuator.some robots use electric motors and solenoids as actuators ,some use a hydraulic system and some use a pneumatic system or all.A robots needs a power source to drive these actuators.It may be a battery ,a pump to pressurize the hydraulic fluid or air compressor or compressed air tanks.The actuators are all wired to an electrical circuit.The circuit powers electrical motors and solenoid directly and it activates the hydraulic system by manipulating electrical valves.The robots ‘s computer controls everthing attached to the circuit.The most common robotic sense is the sense of movement –the robots ability to monitor its own motion.A standard design uses slotted wheels attached to the robots joints (called as rotary encoder).
The most common manufacturing robot is the robotic arm.A typical robotic arm is made up of seven metal segments joined by six joints.The computer controls the robot by rotating individual step motors connected to each joint. This type of robot has six degrees of freedom ,meaning it can pivot in six different ways. Degree of freedom is the one of most important concept in mechanics.This concept is widely used in robotics and kinematics.DOF means how many variables are required to determine position of a mechanism in space.The degree of freedom(DOF) of a rigid body is defined as the number of independent movements it has.To determine the DOF of this body we must consider how many distinct ways the bar can be moved.
A robotics arm’s job is to move an and effector from place to place.one common end effector is a simplied version of the hand, which can grasp and carry different objects. Robotic hands,often have built in pressure sensors that tell the computer how hard the robot is gripping a particular object.Robotic arms are relatively easy to build and program because they only operate within a confined area.There are many opinions ,but important among them are wheels and tracks & legs, but robot designers often look to l egs instead ,because they are more adaptable .buliding legged robots also helps researched understand natural locomotion –it’s a useful excerise in biolological research (you can see in film ENDIRAN).Typically ,hydraulic or pneumatic pistons move robot legs back and forth.A robot designer has to figure out the right combination of piston movements involved in walking and program this information into the robots computer.many mobile robots have a built in,(a collection of gyroscopes for example) that tells the computer when it needs to correct its movements.bipedal locomotion(walked on two legs is inherently unstable ,which makes it very difficult to implement in robots.Remote robots often called puppet robots are useful for exploring dangereous or inaccessible environments ,such as the deep sea or inside a volcano.autonomous robots can act their own,independent of any controller. Simple mobile robots use infrared or ultrasound sensors to see obstacles .These sensors work the same way as animal echolocation .The robot sends out a sound signal or a beam of infrared light and detects the signal reflection.More advanced robots use stereo vision to see the world around them .Two camercas give these robots depth perception ,and image –recognition software gives them the ability to locate and classify various objects.unlike ordinary motors,step motors move in extact increments.This allows the computer to move the arm precisely .The robot uses motion sensors to make sure it moves just the right amount .An industrial robot with six joints closely resembles a human arm –it has a the equivalent of a shoulder an elbow and a wrist.