www.QuestionPaperDownload.com

Code No: R05420306

R05

Set No. 2

IV B.Tech II Semester Regular/Supplementary Examinations,May 2010 ROBOTICS Common to Mechanical Engineering, Production Engineering Time: 3 hours Max Marks: 80 Answer any FIVE Questions All Questions carry equal marks ????? 1. (a) Explain the principle of working of potentiometer. (b) At time t, the excitation voltage to a resolver is 24 V and the voltage across √ the two pairs of stator terminals will be 12 3 V and 12 V. What is the shaft angle? [8+8] 2. Explain how you solve simple inverse kinematic algorithm.

[16]

3. For a planar RR manipulator, derive the Jacobian matrix and find the linear velocity and angular velocity of the end effector. [16] 4. (a) Using WAIT and SIGNAL commands write a program for the press unloading task. (b) Using the 8 × 8 grid, show the path taken by a cartesian coordinate robot if it is desired to move between point ( 2, 1 ) and point ( 8, 2 ) in the grid using linear interpolation. [8+8] 5. (a) What are the various types of joints used in robots? (b) Compare an articulated robot and Cartesian robot with respect to work envelope, manipulative ability and ease of control. [6+10] 6. Consider the forward transformation of the two-joint manipulator shown in figure 6. Given that the length of joint 1, L1=12in, the length of joint 2, L2=10in., the angle θ1=300 and the angle θ2=450 , compute the coordinate position (x and y coordinates) for the end-of-the-arm Pw. [16]

www.QuestionPaperDownload.com

1

www.QuestionPaperDownload.com

Code No: R05420306

R05

Set No. 2

Figure 6 7. (a) Explain the application of industrial Robots in stamping - press operation. (b) What are the requirements of the Robot for spray painting applications? Explain. [8+8] 8. What is remote centre compliance device? What is the lateral error and the angular error involved in inserting a peg in a hole? [4+12] ?????

www.QuestionPaperDownload.com

2

www.QuestionPaperDownload.com

Code No: R05420306

R05

Set No. 4

IV B.Tech II Semester Regular/Supplementary Examinations,May 2010 ROBOTICS Common to Mechanical Engineering, Production Engineering Time: 3 hours Max Marks: 80 Answer any FIVE Questions All Questions carry equal marks ????? 1. (a) Describe the three compliance conditions normally found in robot applications. (b) What is an RCC device? Explain.

[9+7]

2. Show that the rotation matrices about the y-axis and z-axis are unitary.

[16]

3. (a) What are the capabilities and features of Robots in spot welding? Explain. (b) Discuss the problems for robots in arc welding. 4. For a 3 DOF C1  S1 0T1 =   0 0

manipulator - S 1 0 C1 C1 0 S1 0 1 0 0 0 1

arm, the link   transformation C2 0 - S2 C2   S2 0 C2 S2  1T2 =    0 1 0 0 0 0 0 1

[8+8] matrices are   : 1   0  2T 3 =    0 0

0 1 0 0

 0 0 0 0   1 d3  0 1

Determine the Jacobian of the manipulator to express the Cartesian Velocities in terms of joint velocities. [16] 5. (a) Explain the degrees of freedom of a robot with sketches. (b) Explain the various types of joints used in robotics with sketches.

[8+8]

6. (a) A single cubic trajectory is given by θ(t)=10 + 5t + 70t2 - 45t3 and is used over the time interval from t = 0 to t = 1. What are the starting and final positions, velocities and accelerations. (b) A cartesian co-ordinate LLL in is to move its three axes from position (x,y,z) = (0,5,5) to position (x,y,z) = (20,35,15). All distance measures are given in mm the maximum velocities for the three joints are respectively 20 mm/sec, 15 mm/sec and 10 mm/sec. Determine the time required to move each joint it [8+8] if slow motion is used. 7. A dc servometer is used actuate a robot joint. It has a torque constant of 1.25 N.m/A, and a voltage constant of 12 V/kr/min (1 kr/min = 1000 r/min). The armature resistance = 2.5 Ω. At a particular moment during the robot cycle, the joint is not moving and a voltage of 25 V is applied to the motor. (a) Determine the torque of the motor immediately after the voltage is applied. (b) As the motor accelerates, the effect of back - emf is to reduce the torque. Determine the back - emf and the corresponding torque of the motor at 250 and 500 r/min. [8+8]

www.QuestionPaperDownload.com

3

www.QuestionPaperDownload.com

Code No: R05420306

R05

Set No. 4

8. Consider the Unimation PUMA 200 manipulator. This is a six-axis articulated robot with a roll-pitch-roll type of spherical wrist. Use the second half of the D-H algorithm to fill in the kinematic parameters in the table shown, consistent with the link-coordinate diagram. Indicate which parameters are the joint variables. [16] PUMA 200 Kinematic Parameters Axis θ d a α Home 1 1 2 3 4 5 6

?????

www.QuestionPaperDownload.com

4

www.QuestionPaperDownload.com

Code No: R05420306

R05

Set No. 1

IV B.Tech II Semester Regular/Supplementary Examinations,May 2010 ROBOTICS Common to Mechanical Engineering, Production Engineering Time: 3 hours Max Marks: 80 Answer any FIVE Questions All Questions carry equal marks ????? 1. (a) Compare the performance of a dc servo motor with that of a stepper motor. (b) Under what circumstances is the closed - loop operation of stepper motor desirable? Give a simple schematic sketch for the closed loop operation of a stepper motor. [8+8] 2. (a) Explain the terms: Robot anatomy and work volume. (b) Explain the different robotic configurations with neat sketches.

[8+8]

3. Derive the Jacobian matrix for a spatial 3 degree of freedom spherical Manipulator. Using the Jacobian matrix determine the linear velocity and Angular velocity of the end effector. [16] 4. Discuss suitable design of robot end-effectors to grip objects like: (a) Shafts (b) Rings (c) Flanges.

[16]

5. (a) As technology advances, will the human workers lose jobs to robotic workers? Comment. (b) Explain the application of industrial Robots in plastic molding operation. [8+8] 6. (a) Explain the REACT statement of Robot languages, which is used to monitor an incoming signal and to respond to a change in the signal. (b) Discuss the important characteristics of robot - oriented language - motion specification. [8+8] 7. Consider the United States Robots Maker 110 manipulator. This is a five-axis spherical coordinate robot with a pitch-roll spherical wrist. Assign link coordinates using the first half of the D-H algorithm. Label the diagram with a’s and d’s as appropriate. [16] 8. A frame U B was moved along its own n-axis a distance of 5 units and then rotated about its o-axis an angle of 600 , followed by a rotation of about the z-axis; it was then translated about it’s a-axis 3 units and finally rotated about x-axis 450 . (a) Calculate the total transformation performed www.QuestionPaperDownload.com

5

www.QuestionPaperDownload.com

Code No: R05420306

R05

Set No. 1

(b) What angles and movements would we have to make if we were to create the same location and orientation using Cartesian configurations. [8+8] ?????

www.QuestionPaperDownload.com

6

www.QuestionPaperDownload.com

Code No: R05420306

R05

Set No. 3

IV B.Tech II Semester Regular/Supplementary Examinations,May 2010 ROBOTICS Common to Mechanical Engineering, Production Engineering Time: 3 hours Max Marks: 80 Answer any FIVE Questions All Questions carry equal marks ????? 1. Compare the diffiierences between the representation of angular velocity and kinetic velocity of the Lagrange-Euler and Newton-Euler equations of motions. [16] 2. (a) Discuss the robotic inspection in loading and unloading. (b) What characteristics an arc - welding robotic system must have? Explain. [8+8] 3. (a) What is industrial automation? Discuss the diffrent types of automation. (b) How can you relate industrial automation and robotics?

[8+8]

4. (a) What is the rotation matrix for a rotation of 300 about OZ axis, followed by a rotation of 600 about the OX axis, followed by a rotation of 900 about the OY axis? (b) Derive the formula for sin(ϕ+θ) by expanding symbolically the rotation of ϕ and θ using the rotation matrix. [8+8] 5. Given the world coordinates for the TRR:R robot in figure 5 as x=300mm, y=0, z=500mm, and α=450 ; and given that the links have values L0 =0, L1 =400mm, and λ3 has a range from 200mm to 350mm, and L4 =25mm, determine the joint values θ1 , θ2 , λ3 and θ4 . [16]

www.QuestionPaperDownload.com

7

www.QuestionPaperDownload.com

Code No: R05420306

R05

Set No. 3

Figure 5 6. (a) Make a list of internal sensors used in robotic manipulators. Give brief description of their working and uses. (b) What is the velocity of the piston and the force generated by the piston in a pneumatic actuator if the fluid pressure is 0.5 Mpa inside the cylinder, the piston is 40 mm in diameter, and the flow rate is 2 cm3 /sec. [8+8] 7. Consider a two link robot arm and assume that each link is 1m long. The robot arm is required to move from an initial position (x0 , y0 ) = (1.96, 0.50) to a final position (xf , yf ) = (1.00, 0.75). The initial and final velocity and acceleration are zero. Determine the co-efficients of a cubic polynomial at each joint to accomplish the motion. [16] 8. (a) A piston is to be designed to exert an actuation force of 120lb on its extension stroke. The inside diameter of the piston is 2.0in. and the ram diameter is 0.375in. What shop air pressure will be required to provide this actuation force? Use a safety factor of 1.3 in your computations. (b) A vacuum pump to be used in a robot vacuum gripper application is capable of drawing a negative pressure of 4.0 lb/sq.in. compared to atmospheric pressure. The gripper is to be used for lifting stainless steel plates, each plate having dimensions of 15×35 in. and weighing 52lb. Determine the diameter of the suction cups to be used for the robot gripper if it has been decided that two suction cups will be used for the gripper for greater stability. A factor of safety of 1.5 should be used in the design computations. [8+8] ????? www.QuestionPaperDownload.com

8