1. ME 3230 Kinematics & Mechatronics – An Introduction
R. Lindeke, Ph. D.
Introduction

2. ME 3230 Kinematics & Mechatronics
Front Piece Matter
Website:
Easiest way to get there is via Department Home Page– Faculty – Lindeke – Course ME3230
Syllabus:
Meeting Rooms
Course Schedule
Course Grading
Professional Issues
Text Materials:
Required Main Text: Kinematics, Dynamics and Design of Machinery, 2nd Ed. by K. Waldron & G. Kinzel
Mechatronics, Electronic Control Systems in Mech & Electrical Engineering, 3rd Ed. By W. Bolton
Other Readings will be available on electronic reserve at UMD Library, see syllabus
ME 3230 Kinematics & Mechatronics
11/8/2018

3. ME 3230 Kinematics & Mechatronics
Lets Plant our Feet!
The design of Mechanisms (and machines) is the key way that Engineers separate themselves from Scientists!
Science is the study of what is; Engineering is the creation of what is TO BE!
Waldron and Kinzel
So then? Are you ready for the challenge …
ME 3230 Kinematics & Mechatronics
11/8/2018

4. ME 3230 Kinematics & Mechatronics
Some Definitions:
Kinematics:
Kinematics is the study of motion, quite apart from the forces which produce that motion. More specifically [it] is the study of position, displacement, rotation, speed, velocity, and acceleration.
John Uicker, ME Professor at UWisc
Kinematics is a subset of “Solid Mechanics” which deals with the study of relative motion.
Art Erdman, ME Professor at UMTC
Kinematics is the study of position and its time derivatives. Specifically, [it is] concerned with positions, velocities, and accelerations of points and with angular positions, angular velocities, and angular accelerations of solid bodies. It is the study of the GEOMETRY of MOTION.
K. Waldren, ME Professor at Stanford University
ME 3230 Kinematics & Mechatronics
11/8/2018

5. Definitions Continued
Mechanism:
A mechanism is a mechanical device that has the purpose of transferring motion and/or force from a source to an output
Erdman
A mechanism is a machine composed of rigid members that are jointed together.
Waldron
An assemblage of resistant bodies, connected by moveable joints, to form a closed kinematic chain with one link fixed and having the purpose of transforming motion
F. Reuleaux, “The Father of Modern Kinematics” – a German Kinematician whose work marked the beginning of a systematic treatment of kinematics during the 1850’s
ME 3230 Kinematics & Mechatronics
11/8/2018

6. Mechanisms Can Be designed to serve 3 different tasks
These Tasks are as a:
Path Generator where the designer is interested in the path taken by a “Tracer Point”
Function Generator where the relative motion (or forces) of linkage’s (generally focusing) on the links connected to ground are of interest
Motion Generator with the entire motion of the “coupler” portion of the linkage is of interest
ME 3230 Kinematics & Mechatronics
11/8/2018

7. Specific Linkage Tasks:
Extracted from: L.E. Torfason, “A Thesaurus of Mechanisms” in Mechanical Designer’s Notebooks, V. 5 Mechanisms, McGraw Hill, 1990.
Snap Action Mechanisms
Linear Actuators: stationarl screws w/ traveling nuts; stationary nuts w/ traveling screws; Single- and double-acting pneumatic or hydraulic cylinders
Clamping Mechanisms
Locational devices
Rachets and Escapements
Swinging or rocking mechanisms (Oscillators)
ME 3230 Kinematics & Mechatronics
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8. Specific Linkage Tasks:
Reciprocating Mechanisms (Scotch Yoke & Quick-return mechanisms)
Reversing Mechanisms
Couplings & Connectors – for transmitting power between shafts
Sliding connectors
Stop, Pause, and Hesitation Mechanisms – thinking CAMS (but also linkages!)
Curve Generators – following a coupler curve
Straight Line Generators (see images over)
ME 3230 Kinematics & Mechatronics
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9. Straight Line Generator Linkages
From: Uicker, et al, The Theory of Machines and Mechanisms, 3rd ed., Oxford Press, 2003.
ME 3230 Kinematics & Mechatronics
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10. ME 3230 Kinematics & Mechatronics
Definitions, cont.
Joints:
The coupling parts of a mechanism that allow relative motion in some direction(s) while limiting motion in other directions
Lower Pair joints:
Contact between joined links occurs at every point of a surface segment
Higher Pair joints:
Contact between joined links occurs at isolated points or along line segments (implies much high contact forces)
ME 3230 Kinematics & Mechatronics
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11. ME 3230 Kinematics & Mechatronics
Lower Pair Joints:
ME 3230 Kinematics & Mechatronics
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12. ME 3230 Kinematics & Mechatronics
Higher Pair Joints
ME 3230 Kinematics & Mechatronics
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13. ME 3230 Kinematics & Mechatronics
Definitions, cont.
Degrees of Freedom -- Connectivity
A representation of the type of motion permitted by a joint
Number of Degrees of freedom (of a joint or ultimately a mechanism) is equal to the number of independent coordinates needed to uniquely specify the location (position and orientation) of one link to the other in a pair connected by a joint
In Planer Motion, the max number of DOF is ???
In 3-D Motion this number is: ???
ME 3230 Kinematics & Mechatronics
11/8/2018

14. Planer Kinematic Linkages
A Planer linkage is one in which all points velocities are directly parallel to the “Plane of Motion”
Axes of rotation of joints are normal to this plane
Revolute joints are represented by points or small circles
Direction of sliding of all prismatic joints are parallel to this plane
ME 3230 Kinematics & Mechatronics
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15. Representing Linkages
Binary Jointed Link
Ternary Jointed Link
Quaternary Jointed Link
ME 3230 Kinematics & Mechatronics
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16. Conventional Representation of Planer Linkages:
Ternary Link
Binary Link
Quaternary Link
ME 3230 Kinematics & Mechatronics
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17. Representation of Linkages With Prismatic Joints
4-Bar (a) and 6-Bar (b)
Representations
ME 3230 Kinematics & Mechatronics
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18. Linkages of Special Interest
The most fundamental linkage is the 4-bar
It consists of 3 moving links and 1 fixed link
The Links are:
Ground/Base link (fixed)
Input Link (“driver” mover and connected to ground)
Output Link (“driven” mover and connected to ground)
Coupler or Floating Link (moving and connects driver to driven link)
6-Bar Linkages – are extensions of these simple one and are also found extensively
ME 3230 Kinematics & Mechatronics
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19. ME 3230 Kinematics & Mechatronics
A 4-bar Example:
Here we see a model of the Physical Linkage –
And a ‘Linkage Chain’ or ‘Frame Skelton’
ME 3230 Kinematics & Mechatronics
11/8/2018

20. Slider – Crank Mechanism
It is a special Case 4-bar linkage with one “infinitely long” prismatic link
One of The MOST Common mechanisms of all!
Why?
ME 3230 Kinematics & Mechatronics
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21. An Image: Input-Output could be reversed as in the IC Engine!
ME 3230 Kinematics & Mechatronics
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22. Analytical Representation are most important!
Think about converting from a physical device to a reasonable motion equivalent
This is sometimes called the kinematic skeleton or chain (as earlier)
Consider mechanisms as a series of Joints that form a closed (or sometimes open) chain from ground to ground
Standard 4-bar is: RRRR linkage
Slider Crank is: RRRP linkage
ME 3230 Kinematics & Mechatronics
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23. For Example: A Tilt Window Mechanism from Erdman & Sandor’s Text
ME 3230 Kinematics & Mechatronics
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24. ME 3230 Kinematics & Mechatronics
Makes this Skeleton:
ME 3230 Kinematics & Mechatronics
11/8/2018