Download Bachelor of Engineering Robotics Exam - Summer 2006 and more Exams Robotics in PDF only on Docsity!
Cork Institute of Technology
Bachelor of Engineering in Electronic Automation and Robotics - Award
(NFQ Level 7)
Summer 2006
Robotics
(Time: 2 Hours)
Answer Question 1 AND any THREE other questions. All questions carry equal marks.
Examiners: Mr. D. O’Donovan Mr. J. Berry Dr. R. O’Dubhghaill
Q1. (a) Draw a typical low current, H-bridge D.C. motor controller circuit. Briefly describe the operating principles involved. During your discussion refer to the requirement of clamping diodes. [10 %]
(b) In connection with stepper motors, describe the following terms and illustrate their positions on a typical torque/speed curve:
Holding torque Pull-out torque Pull-in torque Pull-in rate Slew range [10 %]
(c) Describe the principle of operation of the Bi-level drive configuration for stepper motors. [5 %]
Q2. (a) Describe the operation of an incremental optical shaft encoder. [8 %]
(b) State the primary limitation associated with this type of encoder. [2 %]
(c) Discuss the types of errors which may arise with using a dead-reckoning approach to robot navigation. [15 %]
Lead Screw
Q3. An optical pickup unit (OPU) of a CD drive is illustrated in Figure 3.1. The OPU runs at 3V and is rated at 13,500rpm. The torque/speed curve is illustrated in Figure A.1 in Appendix A. Calculate: (a) The electrical and mechanical power of the motor? [4 %]
(b) If the gear train has the following ratios and efficiencies:
N1 = 13
N2 = 19
N3 = 12
N4 = 18
Lead = 1mm/rev The spur gear efficiency = 95% The lead screw efficiency is 30%. i. What is the Gear Train Ratio? [3 %] ii. What is the output velocity of the train? [3 %] iii. What is the output torque of the train? [3 %]
iv. What is the output force of the lead screw where F lead screw^2 Lead
= πηΓ? [3 %]
v. What is the output velocity of the lead screw? [3 %] vi. What is the output power of the screw? [3 %] vii. What is system efficiency? [3 %]
Q4. (a) Contrast and compare the characteristics of non-servo and servo-controlled robots. During your discussion distinguish between 1st^ and 2nd^ generation servo systems. [13 %]
(b) Describe the methods of robot arm programming: o Teach and Show [4 %] o Teach-in Programming [4 %] o Off-Line Programming (OLP) [4 %]
Figure 3.1: OPU gear configuration
Spur Gears 1 - 4
Appendix 1:
Figure A.
