Robotics

nxtasyManufacturing

Class exercisesLab work: Show bump exercise. Add sound. Combine

sound & bump.

Homework: postings (hints at topics). Combine sound, bump, timing…

nxtasy.org

• Several Lego Mindstorms user groups

• respository, challenges– may be useful in deciding on a project

• Forum(s) especially good– Example on nxt buttons

NXT-G

• There are wait blocks:– Wait for specific event to happen, such as

triggering sensor, clicking on button, receiving Blue tooth message

– Check value of sensor, button, message

• Which do you want? In more complex situations, such as waiting for one of the 3 buttons, makes sense to use checking block

Cycles through checking if button pressed

Parallel threadsSpecific application: checking timer.• This is a check for nothing happening. The

'active' thread resets the timer each iteration. The other thread exits the loop and issues a stop.

• Note: NXT-G provides 3 timers.• There is a separate wait until time passes block.• Note: loops using logic can loop until true or loop

until false.• timer block has several outputs. Make sure you

use the one you want, in this case, the results of the compare.

Other ways?

• I am sure there are other ways to do this.

Manufacturing exercise

Look around the room (including what you are wearing and carrying around)

List

objects and type of manufacturing process

Classes of manufacturing

• Custom

• Intermittent

• Continuous

May be outdated, or lines less definite.

Types of processing

• Assembly– Putting things together

• Fabrication– Forming, casting, taking away, putting together, etc.– Chemical [type] processing.

IBM terms: process (semiconductor, chip) plants versus box plants

See Taxonomy of Manufacturing:http://en.wikipedia.org/wiki/

Taxonomy_of_manufacturing_processes

Semiconductor manufacturing• Wafer of silicon (crystal needs to be grown and then sliced)• Circuitry ‘laid down’ using various techniques, including

lithography• Slice and dice into chips• Clean room

Moore’s Law: number of transistors in a circuit doubles every 18 months.

How long can this continue????

http://en.wikipedia.org/wiki/Semiconductor_fabricationOld news, but typicalhttp://www.macworld.com/news/2007/01/27/intel/index.phpApple iPadhttp://www.businessweek.com/news/2010-02-02/apple-s-jobs-spurns-intel-

qualcomm-with-a4-ipad-chip-update2-.html

Automation

• Fixed automation

• Flexible automation– Machining…– Robotics

• Variant of flexible automation: – Data-driven, computer integrated

manufacturing…. Including robotics

Painting cars, welding, etc.

• Robot [arms]

• Teach/playback system

• Economical because of health requirements – May not have always been the case

Critical factors for automation (robotics)

• Air quality (e.g. painting cars)• Miniaturization: operation not at human scale.

True in much of computer manufacturing• Accuracy (precision)• Connection to data• Strength• Speed

• Repeatibility (drudgery)

Manufacturing logistics

• Most manufacturing involves multiple steps (aka stages)

• Need to get parts & materials to stations• Need to test• Need to deliver finished products (aka

distribution)

• Issue of out-sourcing (of parts and materials, not people) to other companies and other sites for the same company

Toyota problems

• Did expansion mean less controls on more suppliers?– Bad accelerator pad produced by US supplier– Note: small number of actual incidents,

though several were serious!

Manufacturing methods

• Build to order– Customer orders specific car, computer, etc. This

prompts building of that item.• Build to stock

– Estimate (guess) what will be needed. Build those items.

Exercises:• What are advantages and disadvantages?• What products are typically built one way versus

the other?

Comparison

• Build to order means little or no waste BUT probably less efficient. Need time to switch between products.

• Build to order may be [much] more efficient but may mean that products are produced that no one wants to buy.

When?

• Mass production versus made-to-order.

• The iPod is a mass produced product that the customer customizes, makes very individual…

Comments

• Company choice of products may or may not be important– Early IBM PC products were divided into

different types to give different manufacturing sites work to do. [To my knowledge at that time] PCs were not profitable.

– Sarong type dress example– ?

Just in time manufacturing

• Don’t build product and don’t take delivery of parts until needed.

• Advantages: lower costs for storage, postpone payment, may even postpone ordering

• Disadvantage: no safety net of materials and parts, hard on suppliers.

Quality

• Quality of final product• Quality of parts, materials, sub-assemblies• Shoe-tying: you can tie shoes with laces that are

somewhat frayed and somewhat unbalanced. • Good enough (within spec)

– Don’t pay in time, money, for higher quality than needed

versus • Continual improvement / 6 Sigma

– Aim for highly reliable process. Pays off.– Associated with Japanese manufacturing

Six Sigma (trademark of Motorola!)

• Refers to normal distribution

• Sigma is a standard deviation

• Making a process be such that six sigma are within acceptable bounds means very little is outside…

Preview

• Library research project.

• Propose topic (I will give approval or modification) for presentation– plus '1 pager': abstract + works cited + 1

picture

• Postings are possibilities (must use at least 3 sources)

Posting ideas: [old] People

• Joseph Engelberger Unimation HelpMate• Rodney Brooks Helen Greiner iRobot RedOwl• Marvin Minsky

• Yasuo Kuniyoshi University of Tokyo• Makoto Shimojo University of Electro-Communications

• Ralph Hollis Carnegie Mellon• Russ Taylor Johns Hopkins• William Bargar University of California at Davis• Peter Will USC• Andre Sharon Boston University

Posting ideas: fiction classicsRead story[ies] AND at least 1

review/analysis!• Karl Kapek: RUR• Isaac Asimov: I, Robot (laws of robotics)• Philip Dick: Do Androids Dream of Electric

Sheep (Bladerunner)• Arthur C. Clarke (others): 2001• Anne McCaffrey: The Ship Who Sang• other

Posting ideas

• Big Dog

• Asimo

• Robot soccer (various types)

• Home / Health care– Companions– Versus smart house

• Military drones

• more

Sound

…. is a vibration of a medium (say the air)

The vibration is characterized as a wave

Longitudinal wave: motion of medium in direction of motion of wave:see

http://en.wikipedia.org/wiki/Longitudinal_wave

Characteristics of wave

• Amplitude: maximum disturbance of the field• Frequency: number of times [something]

happens per time unit– Measured in Hz: times/second

• Wavelength: length of one wave, measured from mid-point to mid-point– Equals speed / frequency

• Period: time between successive event– Inverse of frequency

• speed

Sound attributes• Loudness related to amplitude

• Pitch related to frequency

• Most sounds are [very] complex waves– Flute, tuning fork simpler wave pattern than violin– Fourier transform (of fft) is a way to calculate how

sound can be defined as set of simple sine waves– Signal (what you are trying to measure) versus noise

(random, unwanted). Terminology refers to sound AND other signals.

Lego Sound sensor

• Measures what ?????

• Build (add) sensor to base robot• Do NXT brick tests. • With robot connected, Tools/Calibrate

– This downloads program to run on robot.

• Program– Move unlimited until sound sensor tripped– Move with power dependent on sound

• What does sound sensor measure?

Challenge

• Move until sound at some level.

• If sound at high level, turn one way else turn the other way.

NXT-G control structures

• Loop– Until logical condition true or false– Count– Infinite– Sensor test

• If

• If (Switch): multiple values. Need to de-select flat view

NXT-G

• Variables (suit case)– Typed: logic, number, text– Write block and Read block

• Arithmetic, comparison, logic

• Change number to text

• Random (dice) block

Lab

• Show new exercise using bump.• Add sound sensor.• Program

– stop on sound– stop on sound and then turn one way or another

• Combine use of sound and bump sensors.– Include timer, if you like– Also, can include random effect

Homework

• Postings– Manufacturing topics– military drones– health care / home care (smart house)– prosthetics– People– Fiction– ?OR

• Post question on nxtasy