types of robots

types of robots

1. T y p es o f r o b o t s

2. CO-3 Introduction of robotics : Types of robots, Classification, usage, and the Applications of Robots. Mathematical representations of robots: Position and orientations of rigid body, Homogeneous transformations, Representation of joints, Link representation using D-H parameters, Different kinds of Actuators (Stepper, DC servo and AC motors), Sensors (internal and external sensors) Common sensors – encoders, tachometers, strain gauge based force-torque sensors, proximity and distance measuring sensors.

3. 3. Ghosal,A., Robotics: Fundamental Concepts and Analysis, Oxford University Press, 2nd reprint, 2008.3. 3. Fu,K., Gonzalez, R. and Lee, C. S. G., Robotics: Control, S e n sin g,Visio n a n d Intelligence¸ McGraw - Hill, 1987.

4. History ‘robot’ – 1923 – Czech play R.U.R (Rossum’s Universal Robot -1921) by Karel Capek Slave labour

5. Modern Industrial Robot A PUMA 560 robot (Programmable Universal Machine for Assembly) - Unimation T3 (The Tomorrow Tool) -Cincinnati Milacron

6. Robot – definition It is an automatic device that performs functions normally belongs to human or a machine in the form of a human It is a re-programmable multi-functional manipulator designed to move materials, parts, tools or specialized devices through various programmed motions for the performance of a variety of tasks.

7. Re-programmable Re-programmable ---- distinguishes a robot from computer numerically controlled machine CNC

8. Key component in development of Robot Digital Computer feedback control Reason for Reduction in growth of robot Inability of robots to perform task that human operator could perform easily Inability of robots to Avoiding obstacles in a cluttered workspace Inability of robots to Recognizing and manipulating objects- screws, bolts, nuts.. Inability of robots to Adapting and reacting quickly to changes in environment

9. Late 1980-early 1990 Robots – Blind, deaf & dump

10. Late 1980-early 1990 Robots – Blind, deaf & dump Sensors and computing resources Robots can sense Quickly process data from sensors Interact intelligently with environment

11. Present day Robots Detect the presence or absence of object to be manipulated Measure applied forces and moments Obtain the position and orientation of objects in its environment Variety of end-effectors , hands and grippers – grasp and manipulate a wide variety of tools and objects Robot is easier to program, more flexible and more intelligent

12. Classification of robots based on the application environment Environment that is hazardous for humans to operate in, or an environment where the cost of protecting human is very high Environment not hazardous to human beings but where human beings are hazardous to the product

13. Examples Handling of fuel and radioactive material in nuclear power plant Space – satellite Underwater operations Ultra clean room in the electronic industry

14. Classification of robots based on the application environment Tasks that are repetitive, back-breaking and also boring for human beings

15. Human beings cannot maintain the required accuracy because of the monotonous and tedious nature of the task Spray painting and welding of car bodies Loading and unloading of material, parts and tools from other machines Assembly of components – electric motors, computer pheripharals ….

16. Classification of robots based on the application environment 3. Manufacturing of consumer products where the number of items is not very large and the product or the model is frequently changing

17. Television sets, cameras and other audio/video consumer products Reprogramming the robots to handle different parts of newer models are easier than expensive re-tooling and changes in the assembly line

18. Star wars

19. LEGO

20. Asimo ……………By Honda --------

21. Hanson Sophia  is a social  humanoid robot developed  by Hong Kong based company Hanson  Robotics .

22. Da Vinci

23. $2 million ……… Rs 14,18,17,000.00 Indian Rupee

24. Japan 5,500 - 1980…. 65,000 -1985…… 400,000 – 1995 Europe USA

25. Types of Robots Classification based on their number of degrees of freedom/axes Translational envelopes : Moving forward and backward on the X-axis. (Surge) Moving left and right on the Y-axis. (Sway) Moving up and down on the Z-axis. (Heave) Rotational envelopes : Tilting side to side on the X-axis. ( Roll ) Tilting forward and backward on the Y-axis. ( Pitch ) Turning left and right on the Z-axis. ( Yaw ) Degrees of freedom indicates the capability of a robot

26. 6 DOF --- positioning and orienting an object / Tool 5 DOF --- Painting and simple welding

27. Types of Robots Classification based on its Configuration Cartesian Spherical Cylindrical

28. Cartesian system is one that moves in three, orthogonal axes — X, Y, and Z  1. Cartesian

29. 2. Spherical Ball-shaped robot is a mobile robot with spherical external shape A spherical shell serving as the body of the robot and an internal driving unit (IDU) that enables the robot to move . Move by rolling over surfaces. The rolling motion is performed by changing the robot's center of mass (i.e., pendulum-driven system)

30. spherical robot also be referred to a stationary robot with two rotary joints and one prismatic joint which forms a spherical coordinate system

31. 3. Cylindrical It has 3 axes of movement. Two are linear and one circular

32. First 3 joints – used to position an object 2 or 3 additional joints (wrist joints) – used to orient the tool Actuator - device that converts energy into physical motion. -- electric motors, hydraulic or pneumatic cylinders Manipulator - device used to manipulate materials without direct physical contact by the operator Serial Manipulator Parallel manipulator

33. Loop in robotics

34. Serial Manipulator One fixed end A free end – which carries the end-effector or tool No closed loop Parallel manipulator One or more joints fixed to the ground One or more closed loop

35. Classification based on the mode of operation Playback Robot A robot is physically taken through each step of the desired motion by an operator. These recorded positions are simply Played back by the robot by an signal when it required

36. Computer Controlled robot The desired motion is obtained from a computer after computations according to specified algorithms Intelligent Robot It is connected with sensors and processors and is capable of performing tasks – avoiding obstacles, taking simple decisions based on inputs, learn about the environments

37. Technology and Hardware of the Robot Mechanical components Actuators Power transmission devices Sensors Electronic Controllers Computer

38. Main Mechanical components Links connected by joints Various types of bearings End effector

39. Actuators Links are moved by actuators Electric motors – DC / AC servo motor or Stepper motor Pneumatic Hydraulic cylinders Motors – low RPM, lightweight, high torque

40. Power transmission devices Transmission of power and reduce the speed Low-backlash gear sets Harmonic drives Ball screws Stop / hold the robot breaks

41. stepper motors convert an electrical pulse in to a defined angular movement called steps. The  stepper motors   do not require feedback loop to ensure precise movement.   servomotor is a closed-loop servomechanism that uses position feedback to control its motion and final position As the disk rotates, these patterns interrupt the light emitted onto the photo detector, generating a digital or pulse signal output.

42. Servo motor A  servomotor  is a rotary actuator or linear actuator that allows for precise control of angular or linear position, velocity and acceleration

43. It consists of a suitable motor coupled to a sensor for position feedback. It also requires a relatively sophisticated controller, often a dedicated module designed specifically for use with servomotors.

44. A servomotor is a closed-loop servomechanism that uses position feedback to control its motion and final position. The input to its control is a signal (either analogue or digital) representing the position commanded for the output shaft. The motor is paired with some type of position encoder to provide position and speed feedback. In the simplest case, only the position is measured. The measured position of the output is compared to the command position, the external input to the controller. If the output position differs from that required, an error signal is generated which then causes the motor to rotate in either direction, as needed to bring the output shaft to the appropriate position. As the positions approach, the error signal reduces to zero and the motor stops

45. Sensors -- Measures rotation and translation at joints for feedback control Angular rotation – optical encoders Angular velocity -- tachometer Translation and Linear velocity – LVDT (Linear variable Transformer) and video camera Force at the end effector / links – Force-torque sensor – strain gauge

46. Electronics Controllers Microprocessors -- A/D , D/A, Memory… Measured signal – 5v I/P actuators - 12 or 24V Driver – to amplify

47. Computer and Software Set 1 Performs the task of controlling the actuators in a robot Set 2 Supervisory or a master computer where application programs can be developed and stored, fault detection, diagnosis and corrective actions can be taken or where high-level task planner or an expert system can reside

48. Basic Principles in Robotics Interdisciplinary subjects Kinematics Dynamics Control Sensors

49. Kinematics Motion of rigid bodies in a 3D space 6DOF – 6 independent parameter to be fully specified 3 parameter – (position– point on the end effector) 3 parameter – orientation 6DOF – 6 independently actuated joints ---Study the functional relationship b/w the motion at the joints and the motion of the end-effector without reference to the cause of the motion

50. Direct kinematics problem The motion at the end effector for a given motion at the joints Inverse kinematics problem The motion at the joint for a required motion of the end effector

51. Dynamics Study the motion of the links and the end-effector under the action of external forces and torque from the actuators

52. Control Position control Control the force which the robot applied on the environment INTELLIGENT – interacting with the external environment and taking simple decision they need to be equipped with sensors SENSORS - enable the robot to apply the correct amount of force to grip delicate objects.

53. Master Slave Manipulator Systems..