ROBOTICS by R.C.Saini

FUNDAMENTALS OF ROBOTICS

byR.C.SAINI

www.rcsaini.com1www.rcsaini.comwww.rcsaini.comWhat Is Robot ? By RIA (Robotics Industries Association, America)[2]An industrial robot is a reprogrammable, multifunctional manipulator designed to move materials, parts, tools, or special devices through variable programmed motion for the performance of a variety of tasks.

A manipulator (or an industrial robot) is composed of a series of links connected to each other via joints. Each joint usually has an actuator (a motor for eg.) connected to it. These actuators are used to cause relative motion between successive links. One end of the manipulator is usually connected to a stable base and the other end is used to deploy a tool.www.rcsaini.com2Classification of RobotsJIRA (Japanese Industrial Robot Association) [1]Class1: Manual-Handling Device Class2: Fixed Sequence Robot Class3: Variable Sequence Robot Class4: Playback Robot Class5: Numerical Control Robot Class6: Intelligent Robot

RIA (Robotics Industries Association, America)[1]Variable Sequence Robot(Class3) Playback Robot(Class4)Numerical Control Robot(Class5)Intelligent Robot(Class6)

www.rcsaini.com3What is Robotics ?Robotics is the art, knowledge base, and the know-how of designing, applying, and using robots in human endeavors.[1]

Robotics is an interdisciplinary subject that benefits from mechanical engineering, electrical and electronic engineering, computer science, biology, and many other disciplines.

www.rcsaini.com4History Of Robotics[1]1922: Karel apeks novel, Rossums Universal Robots, word Rabota(worker) 1952: NC machine (MIT) 1955: George Devol developed the first programmable robot1955: Denavit-Hartenberg Homogeneous Transformation Matrices1962: Unimation was formed, GM installed its first robot 1967: Mark II (Unimation Inc.) 1968: Shakey(SRI) - intelligent robot 1973: T3(Cincinnati Milacron Inc.) 1978: PUMA (Unimation Inc.) 1983: Robotics Courses 21C: Walking Robots, Mobile Robots, Humanoid Robots

www.rcsaini.com5Advantages V/S Disadvantages of Robots[1,2]Robots increase productivity, safety, efficiency, quality, and consistency of products. Robots can work in hazardous environments without the need.Robots need no environmental comfort.Robots work continuously without experiencing fatigue of problem. Robots have repeatable precision at all times. Robots can be much more accurate than human. Robots can process multiple stimuli or tasks simultaneously. Robots replace human workers creating economic problems.Robots lack capability to respond in emergencies.Robots, although superior in certain senses, have limited capabilities in Degree of freedom, Dexterity, Sensors, Vision system, real time response.Robots are costly, due to Initial cost of equipment, Installation costs, Need for Peripherals, Need for training, Need for programming.

www.rcsaini.com6Robot Components[1]Manipulator or the roverEnd effectorActuatorsSensorsControllerProcessorSoftware

www.rcsaini.com7www.rcsaini.comwww.rcsaini.com7Robot ComponentsManipulator or the rover

This is the main body of the robot which consist of the links, the joints, and the other structural elements.

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[3]Robot ComponentsEnd effectorGrippersToolsWelding attachmentsetc.

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[3]Robot ComponentsActuatorsHydraulicPneumaticElectricSensorsUsed to collect information about the internal state of the robot or to communicate with the outside environment.

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[3]Robot ComponentsController

Processor

Software

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[3]Robots degrees of freedom[1,2]Degrees of Freedom: Number of independent position variables which would has to be specified to locate all parts of a mechanism.In most manipulators this is usually the number of joints.To fully place the object in space and orientate it as desired. The robot will have 6 degrees of freedom.www.rcsaini.com12Robot JointsPrismatic Joint: Linear, No rotation involved(Hydraulic or pneumatic cylinder).

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Revolute Joint: Rotary, (electrically driven with stepper motor, servo motor)

[3][3][3]Robot CoordinatesCartesian/rectangular/gantry (3P) : 3 Prismatic Jointwww.rcsaini.com14

[3]Robot Coordinateswww.rcsaini.com15Cylindrical (R2P) : 2 Prismatic joint and 1 revolute joint

[3]Robot CoordinatesSpherical (2RP) : 1 Prismatic joint and 2 revolute joint

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[3]Robot CoordinatesArticulated/anthropomorphic (3R) : All revolute(Human arm)www.rcsaini.com17

[3]Robot CoordinatesSelective Compliance Assembly Robot Arm (SCARA): 2 paralleled revolute joint and 1 additional prismatic joint

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[3]Robot Reference FramesA robots World, Joint, and Tool reference frames.

Most robots may be programmed to move relative to either of these reference frames.

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[1]Programming Modes[1]Physical Setup: PLC Lead Through/ Teach Mode: Teaching Pendant/ Playback, p-to-p Continuous Walk-Through Mode: Simultaneous joint-movement Software Mode: Use of feedback information

www.rcsaini.com20Robot Characteristics[1,2]Payload: The weight a robot can carry and still remain within its other specifications.Reach: The maximum distance a robot can reach within its work envelope.Precision (validity): defined as how accurately a specified point can be reached 0.001 inch or better.Repeatability (variability): how accurately the same position can be reached if the motion is repeated many times.

www.rcsaini.com21Robot Languages[1,2]Microcomputer Machine Language Level: the most basic and very efficient but difficult to understand to follow.Point-to-Point Level: Funky Cincinnati Milacrons T3. It lacks branching, sensory information.Primitive Motion Level: VAL by Unimation Interpreter based language. Structured Programming Level: This is a compiler based but more difficult to learn. Task-Oriented Level: Not exist yet and proposed IBM in the 1980s.

www.rcsaini.com22Robot Workspacewww.rcsaini.com23

Typical workspaces for common robot configurations[1]Robot Application[1,2]Machine loadingPick and place operationsWeldingPaintingSamplingAssembly operationManufacturingSurveillanceMedical applications Assisting disabled individuals Hazardous environmentsUnderwater, space, and remote locationsEtc.

www.rcsaini.com24ReferencesIntroduction To Robotics by SEED B. NIKUIndustrial Robotics by Mikell P. Groover, Mitchell Weiss, Roger N. Nagel and Nicholas G. OdreyOpen course by Eastern Mediterranean University (EMU), Cyprus(http://opencourses.emu.edu.tr/course/view.php?id=32)www.rcsaini.com25Thank Youwww.rcsaini.com26