Robotics. Lecturer: Dr. Saeed Shiry Ghidary

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1 Robotics Lecturer: Dr. Saeed Shiry Ghidary

2 Outline of Course We will study fundamental algorithms for robotics with: Introduction to industrial robots and Particular emphasis on research in and applications of autonomous mobile robots

3 Method The course consists of Lectures with discussions, Homework assignments, Reading assignments, One of these assignments might involve a (group) project.

4 Course Requirements Each student will: Explore and present a topic in depth, Carry out a small-scale research project, such as a software simulation or a mathematical model. Pass exams and tests.

5 Grading Scheme The grade will break down as follows: Classroom presence and participation: 5% Paper presentation 25% Assignments: 10% Research project: 35% Exams 25% An extra bonus for creative students

6 Text Book The following are suggested readings: Introduction to robotics mechanics and control, second edition. By JOHN J. CRAIG, Addison Wesley, Modeling and control of robot manuplators. By Lorenzo Sciavicco & Bruno Siciliano. McGraw Hill, 1996.

7 Content of the Course Lectures: Introduction Kinematics Inverse kinematics Dynamics Trajectory generation Robot programming languages

8 Content of the Course Presentations: Mobile robot kinematics Perception Mobile robot localization Obstacle avoidance Planning and navigation Sensor fusion Humanoid and legged robots

9 What Is Robotics? Robotics is the intelligent connection of perception to action. Or simply the science of dealing with robots.

10 What Is Robot? ISO, the international standard organization, have formulated the following definition with respect to robots and manipulators Manipulating industrial robot is an automatically controlled, re-programmable, multi-purpose, manipulative machine with several degrees of freedom, which may be either fixed in place or mobile for use in industrial automation applications

11 What Is a Robot? By general agreement a robot is: A programmable machine that imitates the actions or appearance of an intelligent creature usually a human.

12 What Is a Robot? To qualify as a robot, a machine must have the ability for: Sensing and perception: get information from its surroundings. Carry out different tasks: locomotion or manipulation, do something physical such as move or manipulate objects. Re-programmable: can do different things. Function autonomously and/or interact with human beings.

13 Robotics As an Interdisciplinary Science Arts, Politics, Economics, Mathematics, Physics, Control-theory, Cybernetics, Computer science, Artificial Intelligence, Biology, Psychology, Sociology, Social-Psychology, Philosophy, Artificial life, Sports

14 Historical Overview Leonardo da Vinci created many robot-like sketches and designs in the 1500 s. In 1920, the word robot was first used in a play by Karel Capek entitled Rossum s universal robots performed in Paris. In this play small artificial creatures strictly obeyed their master s orders. In Czech and Russian they were called Robotnic, from Robota meaning hard work and drudgery.

15 Historical Overview In 1950, Isaac Asimov introduced the idea of good robots (androids) in his stories and popularized the word robotics. The first robots were thought to be evil human-looking machines.

16 First Industrial Robots Robot manipulators were first realized in 1945 with the onset of nuclear age. In 1961 George C. Devol obtains the first U.S. Robot patent, no. 2,998,237. Joe Engelberger formed Unimation and was the first to market robots. In fact Joseph Engleberger and George Devol were the fathers of industrial robots the first PUMA (programmable universal machine for assembly) robot is developed by Unimation for general motors.

17 Impact Robotics offers benefits such as high reliability, accuracy, and speed of operation. Advantages of industrial robots. Flexibility in production. High productivity. Improve quality of products. Improve quality of human life (safety of personnel) by performing the undesirable jobs.

18 Asimov s Laws of Robotics Asimov invented the three laws of robotics: Robotics offers benefits such as high reliability, accuracy, and speed of operation. A robot may not injure a human being or, through inaction, allow a human being to come to harm. A robot must obey the orders given it by human beings except where such orders conflict with the first law. A robot must protect its own existence as long as such protection does not conflict with the first or second law.

19 Why Use Robots? Application in 4D environments Dangerous Dirty Dull Difficult Application 4A tasks Automation Augmentation Assistance Autonomous

20 Applications of Robotics Service robots Automatic cleaning of (large) areas Client support Agricultural Hazard environments Construction and demolishing Space Military Forests Material Handling Safety Civil Transportation Elderly and Handicapped Entertainment

21 Elements of a Robot System The mechanical structure comprises the links of a manipulator or the body and wheels of a mobile robot. The actuators cause the robot to move. Sensors measure robot motion and sense a robot s environment. A computer controller reads sensors, sends control signals to actuators, interacts with command.

22 Types of Robots Robot Manipulators Mobile Manipulators

23 Trends in Robotics Classical Robotics (mid-70 s) exact models no sensing necessary Hybrids (since 90 s) model-based at higher levels reactive at lower levels Reactive Paradigm (mid-80 s) no models relies heavily on good sensing Probabilistic Robotics (since mid-90 s) integration of models and sensing inaccurate models, inaccurate sensors

24 Industrial Robot Manipulator is a machine, the mechanism of which usually consists of a series of segments jointed or sliding relative to one another, for the purpose of grasping and/or moving objects (pieces or tools) usually in several degrees of freedom.

25 Industrial Robot

26 Robot Parts Base Shoulder Elbow Wrist Tool-plate End-effecter (not shown)

27 How are they used Industrial robots 70% welding and painting 20% pick and place 10% others Research focus on Manipulator control End-effectors design Compliance device Robot hand Visual and force feedback Flexible automation

28 Installed Industrial Robots Japan take the lead, why? Shortage of labor, high labor cost

29 Common Robot Designs Cartesian. Robots which have three linear (P, as opposed to rotational R joints) axes of movement (X, Y, Z). Used for pick and place tasks and to move heavy loads. They can trace out rectangular volumes in 3D space. Cartesian: PPP

30 Common robot designs Cylindrical The positions of these robots are controlled by a radius, a height and an angle (that is, two P joints and one R joint). These robots are commonly used in assembly tasks and can trace out concentric cylinders in 3D space. Cylindrical: RPP

31 Common robot designs Spherical Spherical robots have two rotational R axes and one transnational P (radius) axis. The robots endeffectors can trace out concentric spheres in 3D space. Spherical: RRP

32 Common Robot Designs Articulated. The positions of articulated robots are controlled by three angles, via R joints. These robots resemble the human arm (anthropomorphic). They are the most versatile robots,but also the most difficult to program. Articulated: RRR

The robot arm unit can move up and down, and at an angle around the axis of the cylinder, but

33 Common Robot Designs SCARA (selective compliance articulated robot arm). SCARA robots are a blend of the articulated and cylindrical robots. The robot arm unit can move up and down, and at an angle around the axis of the cylinder, but the arm itself is jointed like a revolute coordinate robot to allow precise and rapid positioning. It consists of three R and one P joints. SCARA: RRP

34 Master/slave Manipulators

35 Parallel Robots Parallel robots have many legs with active and passive joints and links, supporting the load in parallel. Can handle higher loads with greater accuracy, higher speeds, and lighter robot weight;

36 Parallel Robots Workspace of parallel robots is severely restricted compared to equivalent serial robots. Are used in expensive flight simulators, as machining tools, and can be used for highaccuracy, high-repeatability, high-precision robotic surgery

37 Technical Terms in Robotics Speed. The amount of distance per unit time at which the robot can move. M/s. Load bearing capacity (pay load). The maximum weight-carrying capacity of the robot. Accuracy. The ability of a robot to position itself to the desired location with the minimal error (example: 0.001inch).

38 Technical Terms in Robotics Repeatability. The ability of a robot to repeatedly position itself when asked to perform a task multiple times. Work envelope. The maximum reach, or volume within which a robot can operate.

39 Robot Power Sources/actuators Electric motors (DC servomotors). Uses electric motors to position the robot. These robots can be accurate, but are limited in their load-bearing capacity. Hydraulic cylinders (fluid pressure). It can carry very heavy objects, but may not be very accurate. Pneumatic cylinders (air pressure). It is similar to one with a hydraulic drive system; It can carry less weight, but is more compliant (less rigid to disturbing forces).

40 End Effectors Grippers. Grippers are the most common end-effectors. They provide the equivalent of a thumb and an opposing finger, allowing the robot to grasp small parts and manipulate them. Machine tools. Robot end-effectors can also be machine tools such as drills, grinding wheels, cutting wheels and sanders.

41 End Effectors Measuring Instruments Allow the robot to precisely measure parts by running the arm lightly over the part using a measuring probe or gauge. Laser & Water Jet Cutters Use high-intensity laser beams or high-pressure abrasive water jets to cut sheet metal or fiberglass parts to shape. Welding Torches Allow robots to weld parts together. These end-effectors are widely used in the automotive industry.

42 Smart Robot Sensors Vision. Used commonly in electronics assembly to place expensive circuit chips accurately through holes in the circuit boards. Voice. Useful in training the robots. Tactile. Sensors that provide the robot with the ability to touch and feel.

43 Smart Robot Sensors Force/Pressure Help the robot auto-correct for misalignments, or to sense the distribution of loads on irregular geometry. Can be used in conjunction with haptic interfaces to allow the human operator to feel what the robot is exerting on the environment during tele-operation tasks. Proximity Allow the robots to detect the presence of objects that are very close to the arm before the arm actually contacts the objects.

44 Smart Robot Sensors Other sensors Limit Switches Encoder (measures angle) Potentiometer (measures angle or length) LVDT (linear variable displacement transducer, measures length) Strain gauge (measures deflection) Ultrasonic sensor (measures distance) Infrared sensor (measures distance) Light sensor (detects presence)

45 Autonomous Mobile Robots Mobile robots have wheels, legs, or other means to navigate around the workspace under control. An autonomous robot is a machine that operates in a partially unknown and unpredictable environment.

46 Autonomous Mobile Robots Autonomous robots cannot always be programmed to execute predefined actions. These robots require good sensors to see the workspace, avoid collisions,and get the job done.

47 Mobile Robot Functional characteristics: Mobility: Total mobility relative to the environment A certain level of autonomy: Perception ability: Sensing and reacting in the environment

48 The Three Key Questions in Mobile Robotics Where am I? Robot localization Where am I going? Goal determination How do I get there? Motion planning

49 The Three Key Questions in Mobile Robotics To answer these questions the robot has to: Have a model of the environment (given or autonomously built) Perceive and analyze the environment Find its position within the environment Plan and execute the movement

50 Architecture of Robotic Systems Environmental sensors Motion planner Controller Mechanical Structure Mechanical Structure Kinematics model Dynamics model Configuration sensor Actuators: Electrical, Hydraulic, Pneumatic, Artificial Muscle Computation and controllers Sensors Communications User interface Power conversion unit

51 Humanoid Humanoid is an autonomous robot with human-like form and abilities. The autonomous humanoid combines advanced manipulation skills with human-like cognitive processes so as to be able to operate in unchanged man-made environments. There is much current research work aimed at creating human-like robots that can walk, talk, think, see, touch, etc.

RoboCup An international research and education which encourages investigation in the fields of robotics and artificial intelligence using game of soccer.

52 RoboCup An international research and education which encourages investigation in the fields of robotics and artificial intelligence using game of soccer. It focuses on developing cooperation among autonomous agents in a dynamic multi-agent environment. The dream of the RoboCup: By the year 2050, develop a team of fully autonomous humanoid robots that can win against the human world soccer champion team.

53 Summary Robotics:interdisciplinary research Mechanical design Computer science and engineering Electrical engineering Cognitive psychology, perception and neuroscience Research open problems Manipulation, Locomotion Control, Navigation Human-Robot Interaction Learning & Adaptation (AI)

54 Next Course: Kinematics

An Introduction to Robotics. Dr. Bob Williams, Mechanical Engineering, Ohio University. Table of Contents

An Introduction to Robotics. Dr. Bob Williams, Mechanical Engineering, Ohio University. Table of Contents An Introduction to Robotics Dr. Bob Williams, williar4@ohio.edu Mechanical Engineering, Ohio University Table of Contents PHOTO GALLERY... 2 HISTORY... 9 DEFINITIONS... 10 APPLICATIONS... 12 COMMON ROBOT