INF4500-2017Rapid prototyping of robotic systems"Creative use of technology"

Lecture 1

Modified: 14-1-2017

Lecture 1 - outlineINF4500 introduction,

Practical info and organization

Projects

Groups

What is: CAD / RP / CAM(CNC)

Topics for INF4500

Syllabus

Teaching resources

Project 1 - SolidWorks start up

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INF4500INF4500 is a project based course

Home page, facebook

Teaching

2 hours of lectures (plenary sessions) / week by MatsHøvin

2 hour of training exercises (plenary sessions) /week by Mats Høvin

2-(4) hours of supervised practical project work /week

No final examination - "pass" / "no-pass" grade

3 projects, all parts of the projects must be approvedto get a "pass" grade

Deliveries:

Group/individual upload, automatic updates/display

Random visual display/demo for teaching assistants

Plenum presentations of some of the sub projects /

Expert panel demonstration

Students can choose to work in project groups of maximum2 students

Computer aided design (CAD)Typical meaning of CAD:

Using computers (software) to design, simulate, optimize,present and prepare mechanical parts for prototyping /production - engineering. Mostly in 3D

Common software: SolidWorks, Inventor, Catia, AutoCad, PTCCreo Parametric, NX Unigraphics ... hundreds of others

Commonly used modelling technology:NURBS/solids/surfaces/parametric modelling

Other related 3D design areas

Animation/gaming, special effects, architecture, medicine,art, theatre, clothing, concept presentation, ...

Common software: 3ds Max, Maya, ZBrush, Rhinoceros,Blender(free), Cinema 4D, Houdini, Modo, MudBox, ...several hundreds of others

Commonly used modelling technology in many of these fields:polygon/subdivision (SubD)

CAD/3D design tools are fast evolving

In INF4500 we will mainly focus on parametric NURBS baseddesign but also include SubD design. Our main CAD tool isSolidWorks

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Other related termsThere are lot of terms and definitions inthese fast growing areas

PLM - Product lifecycle management -an overall concept decribing the whole"life" of product from idea todisposal

CAE - Computer-aided engineering - amore specific term used for variousengineering analysis and optimizationtasks

Two parallel revolutionsMaking parts from CAD:

3D printing (still a "hyped" revolution?)

Currently: not so many "real" applications ?

Near future: very interesting

CNC machining (silent revolution)

Currently: the "de facto" way to produce highperformance parts, both for production and moldmaking

Future: A new hyped revolution when/if the "do ityourself" CNC community takes off ?

Why is 3D printing so hyped when the industry is full ofeven more impressive production techniques?

The core of 3D printing is to take an original workshoptask and via high-tech tools (programming, mathematics,computer IO and control) offer the productionpossibility to ordinary people as a mini, clean, "pressthe print button" desktop factory

"Unlimited" future production possibilities

...

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Rapid prototyping (RP)Fast physical realization

Usually based on different kinds of "3D printing" technologies wherematerial is added during the process

Concept: after CAD - press the "print button"

Requires "no" mechanical skills (?)

May be a non expensive solution for production of a few parts

Only a limited range of materials are available - mostlypolymer/plastic, metal such as titan has just arrived

To the right ROBINs main 3D printers are shown

Computer Numerical Control(CNC) milling/tuningMay be the final production method

Material is removed from the work piece duringthe process

"Slightly" limited geometry, typical 2-5 axismilling

Requires skilled personnel and advanced tool pathgeneration - no "print" button

"All" kind of materials

Very high geometrical tolerances

High performance parts, or custom made ordinaryparts in low production volumes

CNC machines at ROBIN

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A modern creative designflowA modern creative design/production process

Idea - the "solution to a problem"

Head/paper work First sketches may be drawn onpaper (or processed in head)

CAD - 3D visualization of the idea / necessaryaid in the development of the idea (it may behard to figure out the details in our head) /simulations / adaptation to the environment orother parts.

RP - first physical realization of the idea.This stage must be fast (rapid prototyping) asmany iterations may be needed. In some (rare)cases this may be the final production process.

CNC (CAM) - milling of the final physicaldesign solution - this may be the finalproduction process, otherwise molds for castingcan be milled

In every stage the original idea may be dismissedor new ideas my be spawn

"The devil is in the details"Everybody can have a "great" idea

Claim: Most "great" ideas will fail due to practicaldetails

Many of these details are boring and extremely timeconsuming to try to overcome

Rapid prototyping may be a great help in evaluating /developing / dismissing an idea at an early stage

"In house" RP will further speed op the creative process -no need to delay the process for weeks in every iterationwaiting for an outsourced 3D printed part to arrive

During a creative rapid prototyping process - many newideas may typically be spawned

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MIT FabLab > "hacker space"The FAB_LAB concept: "everybody can now makeeverything"

High technology tools - CAD/RP/CNC

Heavily reduced requirements for practicalcraftsmanship skills, just be a programmer/3D-designer and press the "print" button

Open source FabLab packet containing the righttools - can be exported everywhere (also todevelopment countries)

A basis for new small scale companies based onlocal creative people making custom made "stuff"sheep (relative) and with a short connection tothe local marked

Norwegian examples: Lyngen

Is it only an academic construction with nopractical use, or is it the new way forsustainable development? - Do we really want touse the "print button"?

"Hacker/maker space" - a derived concept.Examples: IFI Sonen, Bitraf, Hackeriet, ...

Topics for INF4500Computer Aided Design of 3D parts

We will use both SubD and parametric NURBS modelling

Rendering and web-based presentation of CAD design

Physics simulation

The mathematics behind the scene

Rapid prototyping (3D printing)

Computer Aided Machining (CAM) - CNC path generation downto G-code

Practical Computer Numerical Control (CNC) milling

Mechatronics for robot applications

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Overview

Teaching resourcesLecture: handouts

Video tutorial: local SolidWorks tutorial

Web: Blender - main operations/shortcuts

Book - free PDF: HSMworks - CNC reference Fundamentals of CNC (free forINF4500 students)

Video tutorial: A very throughout SolidWorks video tutorial set, can befound at Wiley (free)

Book - Akademika:

Mastering CAD/CAM - a good reference for the mathematics of CAD,will only cover parts of the syllabus - expensive

SolidWorks bible - a very throughout reference for SolidWorks, maybe ok to have, expensive

E-book Safari: (free on the UIO net) (only 2 users at the same time)

SolidWorks Surfacing Bible. Advanced use of SolidWorks

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INF4500 in a broader contextContent:

CAD (NURBS), SubD, CAM, practical machining, 3D printing, buildingrobots / CNC machines (electronics, PC/microcontrollerprogramming), optimization of physical geometry - 4-7 differentfields in one course!

Traditionally there are many "walls/borders" between these fields,example:

SubD designers do not necessarily do CAD (design forprototyping/production of parts)

CAD designers do not necessarily do CAM

CNC operators do not usually make CNC machines

Most 3D printing groups do not do CNC milling

...

WhyWhy do we want do it all in INF4500?

Very powerful combinations of coherent skills, making the usable to realize ideas fast and with professional results

Ability to make affordable systems for fast/high qualityrealisation of ideas/products for both personal and industrial(small company) use

Basis for research/innovative development: Many newinnovations/ideas are typically found in the intersection ofdifferent research areas

Making attractive students for the industry which have a broadoverview of coherent fields in modern digitalprototyping/production

Why can we do it all in INF4500?

INF4500 philosophy: Going just deep enough in each area to beable to use it creatively

All necessary knowledge/experience/equipment from these fieldsare collected in the ROBIN group

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WorkloadWill this broad focus make the course extraordinary difficult tofollow?

Not - if you have the right background knowledge - basic skills in:

Object orientated programming (Java)

Simple use of C

Analogue/digital electronics

Linear algebra

When it comes to robotic systems INF4500 is focused at the lower levelslike the physical design and shape of robots, actuators and basiccommunication. INF4500 is not about

Robot intelligence

Complex robotic systems/platforms with advanced sensors, actuatorsand communication schemes

Advanced motion, like humanoid walking

Robot vision and navigation

Industrial robotic systems

Creative flowOverall aim for INF4500: "creative flow"

Definition of Flow:

Flow is the mental state of operation in which aperson performing an activity is fully immersed ina feeling of energized focus, full involvement,and enjoyment in the process of the activity

Conditions for flow

Motivation - lectures (hopefully) and positive labexperiences

Feeling of success by frequent positive feedbackresulting from continuously achieving small goals- skills/theory learned inCAD/CAM/RP/Arduino/mechanics/programming are usedin practical projects/exercises

Creativity can be stimulated by different factors, butin INF4500 we will focus on

Motivation, possibilities, self confidence basedon experience from achieving small goals, reducingfear of failure, positive accepting environment

Free yourself from the traditional way of thinking- MIT scream-bag , rubber band machine gun

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Project 1 - intro"Walking machines" - different kinds of machinery used in researchon algorithms and control systems for generating walking patterns(gaits) in robots.

Inspiration from nature - animals and humans - examples:

Carnegie Mellon Biomimetic Robotics

Boston Dynamics Cheetah DARPA

MIT LegLab

AMBER lab

Passive walkers (underactuated)

Our own Henriette Erna and Mono - gaits evolved byartificial evolution in real time

ROBIN evolutionary robotics by Tønnes Nygaard

Fighting Dynamixel based robots

More Dynamixel based robots

Have a look at youtube: walking robot/machine, biped, legged robot... for more inspiration

DescriptionDesign and prototyping of a two legged walker. Balancing rod isused. A simple design example shown in picture

Part A: SolidWorks design and 3D printing of one Dynamixelservo bracket (toe). Starting today

Part B-F:

SolidWorks - making silicone mould for casting of siliconesole

SolidWorks - design and 3D print the rest of the leggedrobot

Simulation of walking pattern in SolidWorks

Programming the robot control program in Processing (Java)

Documentation of walking pattern by SolidWorks moviegeneration

Physical demonstration of walking for an expert panel forapproval of the project

All project info

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Aim / learning outcome - project 1The main aims of this project can be summarized as follows:

Learning / getting used to parametrized NURB based CAD tools (SolidWorks)

Learning / getting used to 3D printing and path generation

Get some experience with physic simulation and video documentation

Learning / getting used to practical assembly of robots

Get some experience with casting (silicone)

Creative use of technology (creative flow?)

Understanding the widely used RS232 protocol and how to extend it and make it work inpractice by simple Java communication over USB based COM ports. The same concept will beused in project No 2

Getting used to and communicate with an integrated servo system (Dynamixel)

Getting slightly in touch with gait programming for legged robots

What is not chosen to be the focus for this project:

Getting introduced to the Dynamixel community and using pre developed libraries

Making a robot run as fast as possible on a rod (could use a wheel based solution or a car)

Making a legged robot walk with as little effort as possible (could use a commercialhumanoid robot platform, or a cool walking toy robot)

SpecificationsRobot must be "legged" (no wheels with ground contact), 0-4legs

Actuators must be Dynamixel AX12/18, max 2 AX18 units and max4 AX12 units (and/or pneumatics)

Max bus voltage 12V

Robot must be free walking or connected to the central hubsupport system by this T-slot connector. A CAD model of thesupport system can be found here

Dynamixel AX12/18 SolidWork files, PDF

The height of the robot can be freely chosen (central rodsystem height can be altered)

Max size of each printed parts: 200x100x100mm (parts can beassembled by screws)

Maximum printed volume of robot/parts, including failed testprints :) 400cm3

Remember to "Mark" your submitted part with your group number(use the sketch text tool, and extrude cut)

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ExamplesA minimal example - 4 servos (fig. top)

A underactuated example (Jansen linkage), 3 legs, 1servo (fig. bottom) - mechanically complicated

Voluntary competitionsWalking machines in front of expert panel

Speed

Elegance

Prizes/fame/CV-points?

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OrganizationProject groups

Students can choose to design the projects together in groupsof maximum 2 students

Some of the sub-projects are individual designs

Try to find a partner with the same ambition level

If you want a project partner but can't find anyone - send amail to me and you will be mated with the next person thatemails me for the same reason

Now - let's do some real workEven if we have not yet looked at CAD theory, we will nowstart designing in SolidWorks

Why: Easier to understand / see the meaning of the CADtheory when we have been in touch with "the realstuff"

Plan for the rest of the lecture:

For each of you, and me:

Starting up SolidWorks

Going through some SolidWorks demo/basic conceptstogether

Starting to look at project 1a

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Project 1a - startWe will start with designing a simple bracket that can be usedas a part of the walking machine. This part will be the first3D print in the project

This bracket must fit on a Dynamixel "horn" (the movingwheel), Fig. bottom

We will start by manually entering the horn dimensions intothe sketch. Dimensions can be found by the use of a caliperFig. top

Later we will se how we can import a Dynamixel hornbody into Solidworks

Further info on project 1a, will come in the trainingexercise (this Friday)

Intro to SolidworksSolidWorks is a parametric NURBS based CADprogram that is developed by Dassault SystemesCorp. SolidWorks is currently used by over 2million engineers and designers at more than165,000 companies worldwide.

The University of Oslo has got 500 Solidworklicences for educational purposes.

SolidWorks offer a huge number of designfeatures and it is important not to get lostin possibilities.

Recommended INF4500 philosophy: keep thingsas simple as possible

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The Solidworks packageSolidWorks include

2D drawing tools

Technical drawings

Solid modelling

Surface modelling

FEM based simulations: thermal, vibration, drop, .....

Analysis tools

Animation

Motion analyis

Rendering

API

Project / teamwork tools

Various plugins

Export/import

...

Solidworks startupSolidWorks only run at Windows. You can run it on:

Remote desktop against "ifiserv-631.ifi.uio.no"

It may be slow/sluggish

Locally on IFIs PCs: RobinLab / CHILL (and problably onemore location)

It will be fast

Your personal PC/Mac(Bootcamp)

It will be fast

You need to download it first. Downloadinginstructions: contact Yngve Hafting

The first time you run it you may be asked what type ofdesign you typically want to do / work flow customization -choose "Machine design". This can be changed later in theTools-Customize-Options menu

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Solid vs. surface modelling inSolidWorksSolidWorks let you work with parts as they are solid volumes. Toaccomplish this SolidWorks hide the fact that all volumes areboundary represented by 2 dimensionally NURBS patches behind thescenes.

In some cases, typically when you want to make advanced freeformparts the ordinary solid scheme will not be flexible enough, and toextend the modelling possibilities SolidWorks offer you directlyaccess to 2 dimensional NURBS surfaces. When you are finishedmodelling a part based on NURBS surfaces, these surfaces must bemanually stitched together to make a solid. This technique is calledsurface modelling.

Surface modelling in SolidWorks can be relatively complicated andsometimes very frustrating. If the geometry of the part is tocomplex - SubD modelling will often be much easier/productive

Simple class A freeform surfaces with high accuracy requirements area typical target for the SolidWorks surface modelling technique.

We will have a look at surface modelling later in this course.

Typical parametric work flowMost designs are made of on an assembly of parts

Parts are normally based on:

2D sketches - containing most of the parameters + sketchrelations

Can be located on a predefined coordinate system plane oron a plane defined by other features

Solid (volumes) are made from the sketches

Assembly

An assembly is a collection of parts with different kinds ofrelations in between

SolidWorks files can therefore be either

Part-files. In a part file SolidWorks can be in two modus:

Sketch modus, for drawing sketches

3D modus, for making volumes out of sketches

Assembly-files, referring to part-files

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General GUI trick/tipsN.b. Both right and left mouse button are used to selectand open up menus

SHIFT or CNTR + right mouse button can be used to selectmore than one entity

The ECS key can be used to escape an operation when you arefinished

The s-key may be the fastest way to insert features

The s-key menu may be customised to better fit yourpreferences

Making a sketchVideo topics

Opening a new part document

Adding a sketch to one of thebasic planes

Using the s-key. S means shortcut. When you press the s-key,you get a menu with a set oftools that will depend onwhich modus SolidWorks is in

Drawing a simple algebraiccurve

Going out of sketch modus andinto 3D modus

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Line, square, circle,polygon, point, textVideo topics

Different ways of selecting a sketchentity

s-key

Menus

Seach field

Adding text

Follow line

Free location

SplineVideo topics

Adding a simple spline

Moving an end point

Displaying and moving control points

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ExtrudeVideo topics

Simple extrude of a sketch in bothdirections, blind endings

Deleting the extrude operation whilekeeping the sketch

Extruding only a selected contour ofthe sketch (not recommended)

Remember to be out of sketch modus when youextrude a sketch

In the video it is shown a very commonmistake: extruding only some selectedcontours of a sketch. This may work fine insome cases but may give problems in other