MAE156A: Fundamental Principles of Mechanical Design I Instructors: Dr. Nathan Delson Dr. Mostafa (Matthew) Hedayat

Lecture Overview Motivation for Interdisciplinary Design Robot Project Course Logistics Electronics Refresher

Mechanical Design is Dominated by Two Factors The rapid pace of technology development in ALL areas  Electronics  Sensors  Motors  Mechanical Components Intense worldwide competition in most fields  You will continually need to learn new technology and optimize performance

Interdisciplinary Design has Risen to the Forefront of Technological Breakthroughs Effective design of a single product often requires close integration of a wide range of disciplines  Mechanical, Optical, Fluids, Materials  Electronics: Microprocessor and Sensors  Control, Software Examples: Ink jet printing Motion based gaming (accelerometers and soon magnetics) Gene sequencing Interdisciplinary Design is: A required element of an Accredited ME degree A stated priority of UCSD’s Chancellor

Mechatronics A Mechatronic Device has close integration of Mechanical and Electronics High performance requires consideration of both mechanical design, electronics, and control.

Sensors: The Fastest Changing Technology

Objectives & Methods of MAE156A&B Provide a real world design experience in a supportive environment Learning from the iterative nature of the design process through two design projects 7 week robotic/mechatronics design project 14 week sponsored design project Self Guided Learning to develop life-long learning skills

The Old Method for Teaching Machine Design has Limitations There is not enough time to cover all basic machine elements: Technology is changing too quickly  Even with “traditional” components such as gears We will cover select areas in depth Knowledge of electronic control has become essential for many mechanical engineers.

156A Robot Project for Fall 2008 Optimization of a Safe Cracking Robot

Robot Project Objective Rotate the sensor-wheel to read the instructor test pattern consisting of a sequence of 3 dots at different angles. Rotate the flywheel to through the test pattern sequence, such that: The flywheel is held at each position for a period of 0.5 seconds within an accuracy of +/- 5°. Motion accuracy will be measured by instructor IR detector

Robot Project Constraints All teams have the same motors and need to rotate the same inertia. Performance is based upon the fastest time that completes the tasks within the 5 degrees accuracy requirement. For weeks 1-4 optimization is restricted to kit parts. For weeks 5-6 additional components can be purchased from outside vendors ($30 limit).

Robot Project Milestone Week 1: Microprocessor Workshop (during section) Week 2: Structure and Sensor electronics Week 3: Non-optimized Motion Control Week 4: Power train ratio optimization Week 5: Component Optimization Week 6: Robot Contest – Complete Optimization Week 7: Oral Presentations

Emphasis on Proper use of Mechanical and Electronic Components Most engineering projects involve integration of existing components Rapid technology development is occurring at the component level. Use of manufactures’ specifications is critical for building reliable devices. Learning how to use Spec. Sheets Component selection will be critical in sponsored projects.

Emphasis on Analysis and Optimization In the real-world trial and error is expensive Good engineering decisions require both: Solid theoretical analysis Good use of experimental results All robots will achieve the contest task by week 3 Optimization will be the key for final robot performance Individual reports will require justification of design decisions and demonstration of how these increased robot performance.

Areas of Optimization Mechanical Gear ratio Powertrain selection (belt, gear, etc.) Bearings and shafts Other? Interdisciplinary Control algorithm Real-time software Sensor and motor driver electronics Other? Each student will select one mechanical and one interdisciplinary areas to optimize for either the flywheel or sensor arm

Machine Shop Course The machine shop course provides critical skills for fabrication, and developing Design For Manufacturability (DFM) skills. Shop skills will be used for 156B prototype fabrication

Instructional Team Engineering Staff Chris Cassidy Tom Chalfant David Lischer Steve Roberts Instructors Nathan Delson Matthew Hedayat Teaching Assistants Josh Miller Michael Sankur

Logistics Web site: Microprocessor workshop in Design Studio during week 1 Machine shop class in EBU2-B30 starting week 2 Teams makeup 5 students per team based upon section signup Student preference for Industry project Peer review factor (anonymous feedback)  Multiplying factor on team grade Lab assignments due on day of section Starting week 1 (9/29-10/3) Analytical assignments due Friday at 3pm in EBU2-311 bin Starting week 1 on 10/3

Missing Section: Jewish High Holydays or Otherwise You must attend another lab section the same week Lectures will be podcast and made available for those with legitimate reasons. You are responsible for preemptively communicating with your teammates.

Section Logistics Both Sections A00 and B00 will meet together for lectures which will alternate between Dr. Delson and Dr. Hedayat. Robot Project teams will be assigned by instructors, and will be based upon machine shop schedule Sponsored project teams will be based highly on student preference Half the teams will present to and be graded by Dr. Delson, and the other half by Dr. Hedayat. The website schedule will indicate if we meet in the large lecture room, Design Studio, or smaller lecture rooms for student presentations.

MAE 156A Components First 7 Weeks Microprocessor Robot Project 65% of grade Machine Shop Course Weeks % of grade Last 3 Weeks Begin real-world, sponsored design projects, to be completed in 156B Individual Mechanical Components research and risk reduction 25% of grade

New This Year New microprocessors and programming environment UCSD Instructional Improvement Grant More emphasis on analysis and optimization There will be more creativity in the MAE156B sponsored projects

Nate Delson: Why I Became Interested in Design Real-world engineering involves much more than Engineering Science Great designs come about with integration of Design Skills with Engineering Science This is especially true of electromechanical products My portfolio