Template for the Storyboard stage

Title of the concept : Mechanism Synthesis : Motion Generation / Rigid Body Guidance, subject. Mechanical Engineering Name of the author Anirban Guha 1

Definitions of the keywords used in the animation Mechanism: A collection of rigid bodies which can transmit or transform motion Synthesis: Designing a mechanism for a task Rigid Body: An object which cannot be deformed 2

Describe the concept chosen and clearly illustrate how you want to explain the concept in the animation. Rigid body guidance is a class of mechanism synthesis problem where the task is to take an object from one position and orientation to another position and orientation. If only the first and last position and orientation are specified, then it is called a two position synthesis problem. If three positions and orientations are specified, then it is called a three position synthesis problem. Analytical approaches to the mechanism synthesis problem exist, one of which is the Dyad Approach. By this approach it can be shown that a solution may not exist for a “more than five position” synthesis problem. Geometrical approaches for two and three position problems will be described in this exercise. 3

Problem Statement :Describe examples/experiments/analogies through which you will explain (use bullets). Problem 1: Two position synthesis : pages 2 – 6 Problem 2: Three position synthesis for position of fixed pivots not defined : pages Problem 3: Three position synthesis for position of fixed pivots defined in advance – method of rotation around poles : pages 9 – 19 Problem 4: Three position synthesis for position of fixed pivots defined in advance – method of inversion : pages

Problem statement: Stepwise description and illustrations (Add more slides if necessary)‏ 5

List out user interactions that will be there to enhance the understanding of the concept in the animation. At the pull of a slider in these pages, the following should happen - Page 4: The block rotates around the hinge P12 Page 6: A1A0 rotates around A0 to go to A2A0, B1B0 rotates around B0 to go to B2B0 Page 8: A1A0 rotates around A0 and B1B0 rotates around B0. As a result, the link A1B1 moves first to A2B2 and then to A3B3 Page 19: A1A0 rotates around A0 and B1B0 rotates around B0. As a result, the object C1D1 moves first to C2D2 and then to C3D3 Page 24: A1A0 rotates around A0 and B1B0 rotates around B0. As a result, the object C1D1 moves first to C2D2 and then to C3D3 6

A small questionnaire with answers based on the concept. Q: Where would such techniques be needed? A: Design of robotic arm, earth moving equipment Q: Where would these solutions not be useful? A: Where space is at a premium, a cam is used to obtain similar motions, not linkages e.g. many mechanisms in a car Q: How large or small can these devices be? A: As large is earth moving equipment, as small as micromachines 7

Links for further reading/references J.J. Uicker, G. R. Pennock and J.E. Shigley Theory of Machines and Mechanisms Oxford University Press Thomas Bevan, Theory of Machines, Orient Longman Robert L. Norton, Design of Machinery, Tata McGraw-Hill Hartenberg, R.S. and Denavit, J., Kinematic synthesis of linkages, New York : McGraw-Hill Hain, K., Applied kinematics. McGraw-Hill, new York 8