Robotics, Industrial Robotics, Question bank

Industrial Robotics-2 Marks 2013 SELVAM COLLEGE OF TECHNOLGY, NAMAKKAL-3 DEPARTMENT OF MECHANICAL ENGINEERING SUB: INDUSTRIAL ROBOTICS SEM / YEAR: VII / IV UNIVERSITY: ANNA UNIVERITY, CHENNAI YEAR: 2012-2013 Unit-I: 1. Name the FOUR basic robot configurations. a) Cartesian coordinate system b) Cylindrical coordinate system c) Polar or spherical coordinate system d) Revolute coordinate system 2. List out the types of joint Notation. (a) Linear joint, (b) Rotational joint, (c) Twisting joint, (d) Revolving joint. 3. What is meant by a work envelope? The work envelope is described by the surface of the work space. It depends upon the number of types of joints, physical types of joints and links and the range of various joints. 4. Sketch a robot and name its parts. 1. Manipulator (Robot arm) 2. End effector 3. Controller 4. Gripper 5. Actuator 5. What is meant by workspace? The space in which the end point of the robot arm is capable of operating is called as workspace in other words, reach ability of robot arm is known as workspace. 6. What is meant by degeneracy?  Some robots, though, do have a certain joint arrangement in their final orientation joints that can lead to redundancy for certain orientations.  Most industrial robots have 6 or less joints, thus, redundancy is not inherent to their design. 7. List the various types of robot drive system for industrial robots 1. Electric drive: (a) DC motor; (b) Servomotor; (c) Stepper motor 2. Pneumatic drive 3. Hydraulic drive

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Industrial Robotics-2 Marks 2013 8. Sketch and indicate the type of any rotating joints used in robots. (or) Sketch a twisting joint. Rotational (R):

9. What are the types of hydraulic actuators used in robotics? (i) Piston cylinder, (ii) Swing motor, (iii) Hydraulic motor

10. What is meant by robot anatomy?  The robot anatomy is the study of structure of robot that is physical construction of the manipulator's structure.  The mechanical structure of manipulator that consists of rigid bodies (links) connected by means of joints, is segmented into arm that ensures mobility and reachability, a wrist that confers orientation, and an end effectors that performs the required task 11. What are the three degrees of freedom associated with the arm and body motion? Three degrees of freedom associated with the arm and body motion are:  Right (or) Left movement (X-axis motion)  In and out movement (Y -axis motion)  Vertical movement (Z-axis motion)

12. Define the term work envelope.  Work envelop is defined as the envelope (or) space within which the robot can manipulate the end of the wrist.  A robot's work envelope is the range of movement 13. Give some application of robots in industries. (a) Material Handling Application (i) Material transfer application (ii) Machine loading/unloading application. (b) Process Application (i) Welding (ii) Painting (iii) Assembly ; (iv) Machining; (v) Inspection “Allah is great”

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Industrial Robotics-2 Marks 2013 14. How do you specify a robot? (i) Speed; (ii) Actuator (iii) Payload; (iv) Repeatability (v) Accuracy; (vi) Reliability (vii) Manipulator; (viii) End effector ----------------------------------------------------------------------------------------------------------------------------------------------Unit-II: 1. State any two techniques used for object recognition. a) Template matching b) Structural Technique

2. Write about Hall Effect sensors. When a beam of charged particles passes through a magnetic field forces act on the particles and the beam is deflected from the straight line path a current flowing in a conductor is like a beam of moving charges and thus can be defined by magnetic field 3. Classify the robots according to the drive system. 1. Pneumatic drive 2. Hydraulic drive 3. Electric drive (a)DC Motor (b) Servo motor (c) Stepper motor 4. List any two important advantages and disadvantages of a pneumatic gripper. Advantages of pneumatic gripper: 1. Its light weight design. 2. It is possible to distribute the pressure uniformly the entire area. 3. Control is simple 4. Pick up time is very fast. Disadvantages: 1. It is not suitable for heavy loads. 2. Sometime is required to build the pressure. 5. What is inverse Kinematics? It is a scheme to determine joint angles of robot by knowing its position in the world coordinate system. Pjoint = (θ1, θ2, θ3) 6. Name any four proximity sensors used in robotics Sensor, which senses the presence or absence of the object without having physical contact between the objects I) Inductive Sensor 2) Capacitive Sensor 3) Ultrasonic Sensor; 4) Magnetic Sensor

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Industrial Robotics-2 Marks 2013 7. Sketch the screw-actuated mechanical gripper.

8. What are the limitations of adhesive grippers? (i) Adhesive substances losses his tackiness on repeated usage. (ii) Reliability is diminished with successive operations 9. Distinguish between direct and inverse kinematics. (i) Reverse kinematics: It is a scheme to determine joint angles of a robot by knowing its Position in the world coordinate system. PJOINT = (θ1, θ2, θ3) (ii) Direct kinematics: It is a scheme to determine the position of the robot in the world coordinate system by knowing the joint angles and the link parameters of the robot. PWORLD = ( x, y, z ) 10. Differentiate between touch and force sensors. Touch sensor: It senses the presence or absence of the object by having physical contact between the objects. Force sensors: Force sensors are used primarily for measuring the reaction forces developed at the interface between mechanical assemblies 11. List the types of drives used in robots.  Electric drives  Hydraulic drives  Pneumatic drives 12. What is a RCC device? For what purpose is it used in a robot? RCC device means Remote. Center Compliance devices. Uses: (i) RCC device are commonly used in automated assembly applications to provide Compliance for misalignment during assembly. (ii) The compensator is a .compliance device that enhances the flexibility and reliability of a robot

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Industrial Robotics-2 Marks 2013 13. What is a mechanical gripper?  A mechanical gripper is an end effector that uses mechanical finger actuated by mechanism to grasp an object.  Mechanical grippers are used to transfer parts from one location to another or to assemble parts. 14. What is the properties 0f stepper motor?  Stator wiring (number of coils and wire loads).  Number of steps in a complete rotation.  Operating voltage and current.  Amount of force generated (torque).  Maximum rotation speed (steps per second). 15. State the advantage and limitation of hydraulic drive. Advantage: 1. Robust 2. Self lubrication 3. It can also provide precise control at low speeds. 4. High efficiency and high power to size ratio. 5. Hydraulic robots are more capable of withstanding shock loads. Disadvantage: 1. Expensive 2. High maintenance 3. Not energy efficient 4. Noisy 5. Not suited for clean air environments 16. Write the basic principle of servo motor.  A servomotor is used within position control (or) speed control feedback control system.  An electrostatic motor is based on the attraction and repulsion of electrical charge. 17. Give some examples of robot end effector. 1. Gripper 2. Tools 3. Welding equipment 4. End of arm tooling 18. What are the types of grippers?' 1. Mechanical finger grippers. 2. Pneumatic grippers. 3. Hydraulic grippers. 4. Collect gripper. 5. Magnetic gripper. 6. Vacuum gripper. -----------------------------------------------------------------------------------------------------------------------------------------------

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Industrial Robotics-2 Marks 2013 Unit-III: 1. Define a tactile sensor and list the types. Tactile sensor is device that indicates the contact between themselves and some other solid objects. 1. Digital (Touch) Sensor 2. Analogue (Force) Sensor 2. List the two basic types of robot programming method. a. Lead through methods b. Textual robot languages c. Mechanical Programming 3. State the working principle of a touch sensor. Touch sensors in sensors, which senses the presence or absence of the object by having physical contact between the objects. When the button is pressed, an electrical circuit is closed inside the sensors. This lets electricity flow. When the button is released, the circuit is broken and no electricity flows. Touch sensors send a signal when physical contact is made.

4. What is the function of a frame grabber?  A frame grabber is an electronic device that captures individual, digital still frames from an analog video signal or a digital video stream.  It is hardware device used to capture and store the digital image. 5. What are the limitations of hydraulic drive systems? 1) Expensive 2) High maintenance 3) Not energy efficient 4) Noisy 5) Not suited for clean-air environments. 6. What is the purpose of thresholding in analysis? Thresholding is a binary conversion technique in which each pixel is converted into a binary value either black or white.

7. Mention use of machine vision system. (i) This can be used to replace, machining for applications like welding, machining to maintain relationship between tool and work. (ii) Machine vision systems are used for printed circuit board. (iii) This is for the recognition of object from its image. (iv) Achieve 100% accuracy.

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Industrial Robotics-2 Marks 2013 8. Enumerate the difference between open loop and closed loop control system Open loop control system

Closed loop control system

 It is being relatively simple

 More complex

 Low cost

 More cost

 Good reliability

 Greater chance of breakdowns as a consequence of the greater number of components

 The disadvantage is that they are often inaccurate since there are no correction for error

 Relatively accurate in matching the actual to the required values

9. What is meant by template matching? Templates of the parts to be recognized are stored in the vision system memory. The images recorded by the vision camera are compared with the templates stored in memory to determine if a matching part is present. 10. What is a teach pendant? The teach pendant is usually a small handheld control box with combinations of toggle switches, dials and buttons to regulate the robot's physical movement's and program capabilities 11.Classify the position sensors. Main types of position sensors are:  Incremental  Absolute Some other devices which are used as position sensors.  Resistive position sensors.  Linear variable differential transformer (LVDT)  Encoders.  Potentiometer.  Resolver 12. Brief on the working of inductive type proximity sensor.  Inductive proximity sensors operate under the electrical principle of inductance.  Inductance is the phenomenon where fluctuating current, which by definition has a magnetic component induces an electromotive force (emf) is a target object.  To amplify a devices inductance effect, a sensor manufacturer twists wire into a tight coil and runs a current through it. 13. What is triangulation?  Triangulation is a process by which the location of radio transmitter can be determined by measuring either the radial distance, or the direction of the received signal from two (or) three different points.  Triangulation is sometimes used in cellular communication to pin point the geographic position of a user.

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Industrial Robotics-2 Marks 2013 14. What is smoothing in vision system?  Smoothing in vision system is often used to reduce noise within an image (or) to produce a less pixelated image.  Most smoothing methods are based on low pass filter

15. What are the desirable features of sensor? 1. Cost 2. Ease of operation 3. Operating range 4. Accuracy 5. Precision 6. Reliability' 7. Speed of response 8. Calibration 16. List the different types of tactile sensor.  Digital (Touch) Sensor  Analogue (Force) Sensor 17. What are the applications of Machine Vision System?  Inspection  Identification  Visual serving and navigation 18. What are the various techniques in image processing and analysis?  Image data reduction  Segmentation  Feature extraction  Object recognition ----------------------------------------------------------------------------------------------------------------------------------------------Unit-IV: 1. What are Actuators?  Actuators are the devices used for converting hydraulic energy (or) electrical energy into mechanical energy.  In other words, actuators perform a function just opposite to that of the pumps.  The pressurized hydraulic fluid delivered by the hydraulic pump is supplied to the actuators, which converts the energy of the fluid into mechanical energy.  This mechanical energy is used to get the work done. The hydraulic actuators produce linear, rotary, or oscillating motion. 2. What is transformation?  Transformations of frames introduced to make modeling the relocation of objects easier.An object is described with respect to a frame located in the object, and this frame is relocated with a transformation.  The transformation is the result of a sequence of rotations and translations, which are recorded with a transformation equation 3. What is meant by a teach pendent? The teach pendent is usually a small hand held control box with combination of toggle switches, dials and buttons to regulate the robot's physical movements and program capabilities. “Allah is great”

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Industrial Robotics-2 Marks 2013 4. Explain any two commands associated with programming of an end effector. 1. OPEN 2. CLOSE. 3. OPEN I 4. CLOSE I OPEN I: These instructions cause the pneumatic control valves to receive a signal to open the gripper immediately. CLOSE I: These instruction cause the pneumatic control valves to receive a signal to close the gripper. 5. Define the term 'feature extraction ‘ Transforming the input data into the set of feature is called feature extraction. A feature area, diameter, perimeter, is a single parameter that permits ease of comparison and identification. 6. State any two techniques used for object recognition. a) Template matching b) Structural Technique 7. What the benefits of this off line programming?  Reduced down time for programming.  Programming tools make programming easier.  Enables concurrent engineering and reduces product lead time.  Assists cell design and allows process optimization. 8. Explain the reasons for defining points in a program.  To define a working position for the end-effector  To avoid obstacles 9. What is A GV? Automated guided vehicle (AGV) is an independently operated self-propelled vehicle guided along defined pathways in the floor. It is normally powered with batteries. It is mainly used for handling material from one place to other place. 10. List out different types of image compression technique.  Discrete image transforms in image data compression  Hierarchical and progressive compression techniques  Comparison of compression methods 11. What is the command used to execute the speed of the robot in VAL programming?  Speed command is used to define the velocity with which the robot's arm is moved.  SPEED 90: Indicates that the robot should operate at 90% of normal speed during program execution.  SPEED 50 Ips: Which indicates the speed of the end effector during program execution would be 50 in/sec. 12. Write the meaning of the following command: DMOVE (1, 10) DMOVE (< 4, 5, 6> < 30, - 45, 90>) Solution: “Allah is great”

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Industrial Robotics-2 Marks 2013  DMOVE is the motion command for an Incremental (or) Delta.move.  In parenthesis the joint and the distance of incremental move are specified. Example 1: DMOVE (1, 10) Ist IInd  Ist position indicates the joint number.  IInd position indicates the distance of the incremental moves.  Joint 1 moves by 10 inch. Example 2: DMOVE (< 4, 5, 6> < 30, - 45, 90>)  The motion commands an incremental move of axes 4, 5, 6 and by 30°, - 45° and 90° respectively. 13. What is reverse kinematics? It is a scheme to determine joint angles of robot by knowing its position; in the world coordinate system.

14. Define degrees of freedom It is defined as one of the variables required to define the motion of a body in space. Each joint in a robotic system gives the robot one degrees of freedom. 15. Show the relation usd in forward & reverse transformation of 2degrees of freedom manipulator

16. What is teach pendant? The teach pendant is usually a small handheld control box with combination of toggle switches, dials and buttons to regulate the robot's physical movements and program capabilities. ----------------------------------------------------------------------------------------------------------------------------------------------Unit-V: 1. What is continuous path programming? It is the types of programming were the motion cycle involves smooth complex Curvilinear movements of robot arm. 2. What is teach pendant? The teach pendant is usually a small handheld control box with combinations of toggle switches, dials and buttons to regulate the robot's physical movements and program capabilities. “Allah is great”

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Industrial Robotics-2 Marks 2013 3.List any two important considerations for robot safety.  Environmental condition.  Location and installation requirement. ,  Human errors.  Mode of operation 4. How do you calculate the robot economics by return of investment method?

5. What is the purpose of structured lighting? The intersection of the sheet with objects in the work space yields a light stripe which is viewed through 'a television camera displaced a distance from the light source. The stripe pattern is easily analyzed by a computer to obtain range information. 6. What are the different methods of economic analysis? 1) Payback method 2) Equivalent uniform annual cost (EUAC) method 3) Return on investment (ROI) method 7. What are the general characteristics that make potential robot application technically practical and economically feasible? Hazardous or uncomfortable working conditions Repetitive operations Difficult handling jobs Multicast operation 8. What are the steps to be followed by the company in order to implement robot programs in its operations?  Initial familiarization with the technology.  Plant survey to identify potential applications.  Selection of the application.  Selection of the robot.  Detailed economic analysis and capital authorization.  Planning and engineering the installation.  Installation. 9. What is meant by image analysis? Image analysis ids the collection of processes in which a captured image that is prepared by image processing is analyzed in order to extract information about the image and to identify objects or facts about the object or its environment.

10. Give two applications of robot in machining.  Drilling;  Grinding; “Allah is great”

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Industrial Robotics-2 Marks 2013  Reaming;  Tapping  Deburring 11. Calculate the payback period for a robot project with the following data: Net annual cash flow Rs. 45,000, Investment cost Rs. 1, 00,000 Given: Net annual cash flow = Rs. 45,000;

Investment cost Rs. 1,00,000

To find: Pay back period Solution:

12. Which data are required to perform economic analysis of a robot project?  Expected rate of return.  Payout and investment's expected life.  Risk is not making investment.  Cost and risk incase of failure.  Opportunity cost that is the return from alternative investment. 13. What are the three levels of safely sensor systems in robotics defined by National Bureau of Standards? The National Bureau of standards defines three levels of safely sensor system in robotics. Level 1 - Perimeter penetration detection Level 2 - Intruder detection inside the work cell Level 3 Intruder detection in the immediate vicinity of the robot. 15. List the typical MOTION command. 1. MOVE 2. APPRO 3. DEPART 4. DMOVE 16. List out types of A GV vehicles. 1. To wing vehicles 2. Unit load vehicles 3. Pallet truck vehicles 4. Fork truck vehicles 5. Light load vehicles 6. Assembly line vehicles 17. What are types of robots commonly used for machine loading and unloading operation? 1. Servo control robot (point to point) 2. Non-servo robot (pick and place robot) “Allah is great”

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Industrial Robotics-2 Marks 2013 18. Write two aspects of the safety issue in robotics. 1. Redundancy 2. Back up system -----------------------------------------------------------------------------------------------------------------------------------------------

Prepared by, I.Sirajudeen, M.Tech, Asst. Professor, Department of Mechanical Engineering Selvam College of technology, Namakkal

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