Thursday, March 19, 2015

Build car chassis from scratch II

There was an earlier post about Building motorcar from scratch but it uses big wheels not included in the LEGO WeDo Basic set and the LEGO Resource set. Further, because of the choice of gears plus the big wheels, the car runs too fast. Even though I later changed the gearing to make car move slower, a new design is in order.

So I guided one of my grandson to build a chasis so that he can command "Jalan" (Malay word for move) to make the car move by making motor . And by taking apart the car and taking photos along the way, the photos in sequence can act as building instruction:

Step 1: base
build LEGO car chassis base from scratch

Step 2: Add motor and 9 tooth spur gearte
build LEGO car chassis from scratch 2 add motor

Step 3: Add frame, crown gear and axles
build LEGO car chassis from scratch add frame

Step 4: Add wheels
building LEGO car chassis from scratch final step, add wheels

With this small spur gear turns bigger crown gear which then rotates small wheels, the car runs sufficiently slow and is preferably for making that sound controld motorcar.




Saturday, March 14, 2015

Demo: computer microphone as sound sensor for LEGO Wedo

Does LEGO WeDo 9580 really have a sound sensor? Yes and no. The LEGO WeDo basic set comes only with 2 sensors, a "motion" sensor (actually distance sensor) and tilt sensor. No sound sensor. The WeDo Resource Set 9585 also do not come with any sensor at all.

So where does this WeDo sound sensor come from. Actually the computer's mike (microphone) with the software sound input block together can serve as a sound sensor. The program below comprising START block, Display block with microphone input, WAIT block so that the display don't change so fast, and the REPEAT loop

program to demonstrate computer mike as Lego Wedo sound sensor

The video below shows the number on the screen display changing with the sound loudness. Note: the values ranged from 0 to 10:



Friday, March 13, 2015

Hispabrick magazine: Introduction to robotics with WeDo

The first WeDo related article in Hispabrick Magazine Volume 016 is titled "An introduction to robotics for the youth with LEGO WeDo" by Diego Galvez It starts with a comparison of WeDo with Mindstorms:

Mindstorms 9797 WeDo
437 pieces 158 pieces
3 motors 1 motor
5 sensors 2 sensors (3 plus computer mike)
1 controller 1 hub

Note that while it is correct to say that the WeDo set has only 2 sensors, actually it can be consider to have 3 with the third one being the computer microphone which can be used as a sound sensor as explained in Sound controlled WeDo motor.

Diego says that WeDo is easier to use plus allows development complex prototypes including a line follower (see video) so it should not be considered as only for kids.

After describing the components (USB hub, motor, tilt sensor, distance sensor, lights (bought separately), the article goes on to describe how the development of prototype can proceed from
Design > Build > Program > Test > Document and share

Video: Line following robot with LEGO WeDo



Download Hispabrick Magazine Vol. 016

Hispabrick Magazine: Topics on LEGO WeDo, NXT, Mindstorms

Hispabricks Magazines contains lots of very good articles on LEGO WeDo, LEGO NXT and LEGO Mindstorms together with many articles related to LEGO which can be downloaded for free. If you are only interestic in Robotics for Children topics, it is time consuming to browse through all the articles to search for robotics topics you are interested in.

Thus for your convenience I have listed below only robtics related article together with the magazine Volume numbers, page numbers and topics so that you can quickly go to the topic you want to read. Will update list when Hispabrick Mag publish new issue plus active clickable links are links to any summaries I of the article when I have publish them:

Vol Pg Topic  
HM004 29 Introduction to Robotics with LEGO Mindstorms  
HM005 31 Introduction to Robotics with LEGO Mindstorms (II)  
HM006 31 Introduction to Robotics with LEGO Mindstorms (III)  
HM007 28 Introduction to Robotics with LEGO Mindstorms (IV)  
HM008 16 MCP - The Ambassadors of Mindstorms  
HM008 20 A PID Controller for LEGO Mindstorms Robots (Part 1)  
HM008 30 Introduction to Robotics with LEGO Mindstorms (V)  
HM009 30 MCP, The origins x
HM009 32 Interview: John Hansen, software engineer x
HM009 33 Interview: Ralph Hempel, engineer, embedded systems x
HM009 34 A PID Controller for LEGO Mindstorms Robots (Part 2) x
HM009 41 Introduction to Robotics with LEGO Mindstorms (VI) x
HM010 62 Introduction to Robotics with LEGO Mindstorms (VII)  
HM010 62 Mindstorms at LEGOWorld Copenhague 2011  
HM011 55 Introduction to Robotics with LEGO Mindstorms (VIII)  
HM012 56 Introduction to Robotics with LEGO Mindstorms (IX)  
HM013 55 Introduction to Robotics with LEGO Mindstorms (X)  
HM014 58 Introduction to Robotics with LEGO Mindstorms (XI)  
HM015 56 Introduction to Robotics with LEGO Mindstorms (XII)  
HM016 26 The LEGO Mindstorms Evolution  
HM016 29 Robotics with LEGO WeDo  
HM016 44 Introduction to Robotics with LEGO Mindstorms (XIII)  
HM017 31 NXT2WIFI  
HM017 33 LEGO Rover with NXT2WIFI  
HM017 36 Designing the EV3 Education Core Set  
HM017 41 Homemade sensors for NXT: a multiplexor  
HM017 46 Robotics with LEGO WeDo (II)  
HM017 49 LEGO WeDo  
HM017 60 Introduction to Robotics with LEGO Mindstorms (XIV)  
HM018 50 Robotics with LEGO WeDo (III)  
HM018 52 LEGO WeDo (II)  
HM018 57 Introduction to Robotics with LEGO Mindstorms (XV)  
HM019 50 TETRIX with LEGO Mindstorms NXT  
HM019 58 Robotics with LEGO WeDo (IV)  
HM019 61 LEGO WeDo (III)  
HM019 68 Introduction to Robotics with LEGO Mindstorms (XVI)  
HM019 84 Review: The LEGO Mindstorms EV3 Laboratory  
HM020 55 Robotics with LEGO WeDo (V)  
HM020 58 LEGO WeDo (IV)  
HM020 64 Introduction to Robotics with LEGO Mindstorms (XVII)  
HM020
74 Review: The LEGO Mindstorms EV3 Discovery Book  
HM021 56 Robotics with LEGO WeDo (VI)  
HM021 59 LEGO WeDo (V)  
HM021 65 Introduction to Robotics with LEGO Mindstorms (XVII)  

Thursday, March 12, 2015

Command motor to move in 41 languages

Video demonstrating voice command MOVE in 41 languages to make LEGO Power Function motor move using LEGO Wedo robotic program. Earlier post with explanation and program at Sound activated motor.



Footnote: pronunciation of MOVE in 41 languages made with Google Translate:

The word MOVE in 41 languages

English,
Afrikans,
Albanian,
Arabic,

Wednesday, March 11, 2015

History of robots with videos



Definitions of a robot:
1. A machine designed to accomplish a task (eg like a full function calculator)
2. A machine that uses their programming to make decisions - sense, make decision, act

Componenents of a robot:
1. sensors for input
2. control systems for decision making
3. end effectors for output (such as action)

Robots first became useful as industrial robots since factory work can be repetitive, often involve lifting heavy stuff

1961: First industrial robot - Unimate (see video) by Kawasaki used in General Motors assembly line, a giant robotic arm, task to stack and weld heavy metal pieces over and over again.

1974: IRB6 created, first electric industrial robot controlled by a microcomputer, 16KB RAM, programmable, four digits LED display, developed by Swedish ABB for polishing steel tubes, etc, easier to program.

MACHINE VISION and ARTIFICIAL INTELLIGENCE, do human tasks like translate languages, play chess, recognize objects

Difficulties, incredibly difficult to actually get the programs to interact with the real world.

Machine vision and Artificial intelligence help robot object recognition and react in real time

First industrial application of machine vision and AI: Consight uses 3 separate robotis to recognize and sort 6 different objects

Baxter the humanoid industrial robot (Video: see Baxter in action). However, Baxter can't walk, climb stairs, talk, lift weights more then 2.2kg, but can be quickly programmed to do practically anything.
But it need to be told what to do (no Artificial Intelligence)

Wabot 1 (Video: Wabot V1.0), first full-scale humanoid robot, developed in Waseda Uniniversity in Japan in 1973. Have arms, legs, vision, can walk, can pick things up, talk, but take 45 seconds to take 1 step. (see also Video: Wabot 2)

Next progress: Single function robot programmed to do 1 task, example, vacuum floor, mow lawn, wash windows, clean pool.

Next progress: Honda's Asimo (sse Asimo video), walk 6 km per hour, climb up and down stairs, carry a tray, push a cart, a research robot not available for sale.

BEAR (Battlefield Extraction-Assist Robot, see video) a military robot. Have some humanoid components like a head, 2 arms but legs are 2 tracks like a battletank. Can move in rough terrain, climb stairs, carry injured soldiers back to base.

DARPA: Defense Advanced Research Projects Agency. Hold competitions, contest for autonomous vehicles than can move hundreds of miles. DARPA Robotics Challenge Finals. Aim to develop robots that can be sent into dangerous situations without endangering human.

Video showing Unimate industrial robot



Video: Honda's Asimo


Video showing IRB6 industrial robot



Video: see Baxter robot in action



Video Wabot Ver 1.0



Video Wabot 2



Video: BEAR military robot overview


Finally, here is another video about History of Robotics


Sound controlled LEGO WeDo motor

This post will demonstrate how to program a LEGO Power Function motor to move on sound input. We do not need a specific sensor to do this but it will use the computer microphone as the sensor to pick up sound. The Wedo program will consist of a START block, Wait for block, Motor turn this way block, Motor turn for 4 seconds block, Wait block and Repeat block plus a sound input as shown below:

Lego Wedo Robotics sound controlled motor program

On clicking START, the Wait block will wait for input of sound from the "sound sensor" (computer mike). On hearing sound, the next block turn the motor this way (clockwise) and following block set the motor to turn 3 seconds. The final WAIT 2 seconds block have to be added in to force an interval before the program loop back to the START to repeat. If this is not added, the sound of the motor turning itself will then trigger to motor to move again and the program will go through continuous looping without waiting for the intended sound to start.

See video below. Also see how we can use this to have a Sound controlled car which moves on a sound command eg. clap hands.



Application: Sound controlled car


There is an earlier post about Building computer controlled car. All we need to do to have a sound controlled car is to connect the motor shown below to the computer and setup the above program to make the car move on sound command such as clap of the hands:

Add wheels onto axles
Connect motor to computer plus above program to make car move on sound input


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