1. What is kinematics?

Kinematics will enable us to calculate what each joint variable must be if we desire the

hand to be located at a particular point and have a particular orientation.

2. Define statics.

Statics deals with force which acts on the various parts which are assumed to be rest.

3. What is link?

A link may be defined as a member (or) a combination of member of mechanism

connecting other members and having motion to them.

Link of machine may transfer both power and motion

4. What is forward kinematics?

It is a scheme to determine joint angle by robot knowing its position in the world

coordinate system

5. What is reverse 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 parameter of the robot.

6. Define manipulator kinematics.

Manipulator kinematics is connected with the position and orientation of the robots

end of arm or end effector attached to it as a function of time but without regard for

the effects of force (or) mass.

7. Write about transformation.

Transformation of frames introduced to make modeling the relocation of

object easier.

An object is described with respect to a frame located in the object, and

this frame is reloaded with transformation.

8. Explain kinematic model.

Before a robot can move its hand to an object must be located relative to

it. There is currently no simple method for measuring the location of the

robot hand.

Most robot calculated the position of their hand using kinematic model of

their arm.

9. Write steps to drive kinematics model?

1) Assign D-H coordination frame

2) Find link parameter

3) Transformation matrices of adjacent joints

4) Calculate kinematic matrix

5) When necessary, Euler angle representation

10. Give a method to salve forward kinematic problems?

Denavit-Hartenberg conversion

11. Give a method to salve inverse kinematic problems?

Closed form (or) Analytical solutions

numerical solutions

12. When a robot singularity will occurs?

A robot singularity occurs when robot axes are redundant (more axes then necessary

to cause the same motion) or when the robot is in certain configurations that require

extremely high joint rates to move at some nominal speed in Cartesian space.

13. Explain redundancy?

Most industrial robots have 6 or less joints, thus, redundancy is not inherent to

their design.

Some robots, though, do not have a certain joint arrangement in their final

orientation joints that can lead to redundancy for certain orientations. For

example, some robots have the final three joint axes (joints 4, 5 and 6 in a six axis

robot) arranged in a roll, pitch, roll sequence.

14. Differentiate between Forward kinematics and reverse kinematics?

Forward kinematics:

Given the joint angles, determine the position and orientation of the end

effector.

The outcome of the forward kinematics problem is always unique. There are no

multiple solution.

Inverse kinematics:

Given the position and the orientation of the end effector, determine the

numerical values for the joint variable.

This problem is not quite straight forward like the forward kinematic problem

It is not possible to obtain closed form solutions due to the non-linear

simultaneous equations

15. What do you mean by link twist and link length? 16. What are the parameters for kinematic modeling? 17. What is homogeneous transformation? 18. Differentiate Cartesian space and joint space? 19. Differentiate joint coordinates and world coordinates? 20. Define D-H Parameters? 21. What are fundamental rotation matrices? 22. What is dexterous work space?

Long Answers

1. Explain D-H notation used for solving kinematics equation?

2. Explain Link frame assignment Algorithm for forward kinematics?

3. What is a homogeneous transformation in Robot kinematics? For a vector 20 i +

25 j + 10 k, perform a translation by a distance of 8 in x direction, 7 in y

direction and 0 in z direction

4. Discuss the different inputs to an inverse kinematics algorithm? Explain the

solution of a simple inverse kinematic algorithm.

5. What is homogenous transformation of coordinates? Write the homogenous

transformation matrix for translation in 3D.

6. Write homogenous transformation matrices for translation followed by rotation.

7. Write homogenous transformation matrices for rotation in 3D.

8. Determine a T matrix that represents a rotation through an angle about OX axis,

followed by a rotation of about the OY axis. 9. Write the homogenous transform matrix for a rotation of 90o about the z axis

followed by a rotation of -90o about the axis, followed by a translation of ( 3,7,9 )

10. Explain the geometric based direct kinematic analysis of articulated robot.

11. Determine the rotation matrix for a rotation of 450 about y-axis followed by a

rotation of 1200 about z-axis and a final rotation of 900 about x-axis.

12. Derive rotation matrix about Y-axis.

13. Determine the transformation matrix T that represents a translation of a units

along x-axis, followed by a rotation of about x-axis and followed by a rotation of

about z-axis.

14. What is homogenous transformation of coordinates? Explain four sub matrices.

15. Explain the implementation of DH Convention for a links coordinate system and

joint parameters.

16. For the point [3 7 5] perform the following operations

Rotate 300 about X-axis

Translate 8 units along y-axis

Rotate 300 about x then translate 6 units along Y- axis.

Rotate 900 about z-axis.

17. For the pick and place type of robot, the gripper is initially at location (60, 50, 80)

and the following movements are in sequence.

i) Rotation about x-axis by 90.

ii) Translation along z by 30 units.

Find the position of gripper with respect to the original system by using

transformation matrix method.

18. Explain the forward kinematics associated with planar 3R manipulator.

19. For a 3-DOF manipulator arm shown in figure assign frames and obtain joint link

parameters. Also determine the position of tool tip with respect to base frame.

20. What are forward and inverse transformations? Draw a neat sketch of a jointed

arm robot (RR) manipulator with 2 degrees of freedom. Derive the expression for

forward and inverse transformation of a 2D point.

21. Draw and explain the link-coordinate diagram of four-axis SCARA robot.

22. A frame is given two rotations, one about x-axis by 600 and other about y-axis

by450. Show that Rx Ry Ry Rx. Explain why?

23. A 3-DOF Articulated robotic arm is shown in figure obtain the transformation

matrix for the end point.

24. a) Write the homogenous transform matrix for a rotation of 90o about the z axis

followed by a rotation of -90o about the axis, followed by a translation of ( 3,7,9 )

25. What do you understand by skew transformation? Where these transformations

are useful.

26. Determine orientation matrix for ZXZ Euler angle rotation.

27. Explain the Inverse kinematics associated with planar 3R manipulator.