Thursday, December 31, 2009

Cool Tool: DSO Nano $89 Digital Storage Oscilloscope

The reviews and mods for the DSO Nano from Seeed Studio are looking pretty good. Even with limited bandwidth and single channel input, it seems like a good addition to your toolbox. Also these antistatic bamboo tweezers are awesome.

DSO Nano Video from fanxiang on Vimeo.

Wednesday, December 30, 2009

Magnetic Holder for Hex Drivers

Here is another previously mentioned thing uploaded to Thingiverse. This is a magnetic tool holder for Wiha series 263 hex drivers, which are a great alternative to losing hex keys over and over again and ending up with 8 sets of hex keys which are all missing the 2mm wrench.

Tuesday, December 29, 2009

Gravity can't kill it

Note the laser micro-machining at 0:40, I will be stealing that idea.

[From: IEEE Spectrum]

Four Bar Mechanism Release Latch

Previously, we mentioned a four bar mechanism that could be used as a release latch for robot payloads and now it is available on Thingiverse.

DIY Molded Rubber Wheels

If you are looking at building your own robot wheels. The design for these DIY wheel molds and assembly instructions previously mentioned have been uploaded to Thingiverse.

Wednesday, December 23, 2009

Happy Holidays

May they be filled with both digital and analog, and low on unwanted thermodynamics.

The snowflakes can be found on Thingiverse if you would like to make your own DIY ornaments.

Tuesday, December 22, 2009

Pro/E Tip: Incomplete Sections

Have you ever been drawing a part in Pro/Engineer and found yourself stuck with an incomplete section and no idea how to fix it?

From the menubar select Sketch>Diagnostics>Highlight Open Ends and the source of your problems will become clear.

Sunday, December 20, 2009

Micromouse, Superfast

Kato-san has more video of his micromouse running a maze at an end of year party in Chubu. It appears that to improve his performance in the future he is looking at moving beyond rotary encoders. This should help with wheel slip, especially at high accelerations. Perhaps the optical sensors from a lazer mouse would work well for this.

Friday, December 18, 2009

gEDA and Spice

Previously we looked at the gEDA toolset for circuit design, and concluded that it needed more work before it is competitive with Eagle. It turns out that the version shipping with Ubuntu 9.10 is 1.4.3-1 which is by far inferior to the latest version It's still not perfect but it is about 50% less annoying to use and I can actually see myself using it for a project now.

The spice simulation tools for gEDA are not perfect by any means but good results can be achieved. This is a good tutorial that shows how to use gschem and ngspice to perform a simulation.

There are some other interesting tools for working circuit simulation. Dataplot is data viewer for ngspice and gnucap simulations results. The developer Werner Hoch has also released a spice circuit optimizer and some other interesting tools.

If these tools keep getting better at this rate it's only a matter of time before gEDA and other open source tools are competitive with Orcad and Eagle. As time goes towards infinity open source software will converge to the winning solution.

Everything is under Control


A little holiday reading perhaps?

Thursday, December 17, 2009

Roboni-i Robot Swarm

Roboni-i shows off by playing follow the leader and performing a synchronized dance.

Security through obscurity: Predator UAV Hacked

According this Wall Street Journal article, militants in Iraq and Afghanistan have been able to receive video footage from UAVs using commercially available software.

The potential drone vulnerability lies in an unencrypted downlink between the unmanned craft and ground control. The U.S. government has known about the flaw since the U.S. campaign in Bosnia in the 1990s, current and former officials said. But the Pentagon assumed local adversaries wouldn't know how to exploit it, the officials said.

Today, the Air Force is buying hundreds of Reaper drones, a newer model, whose video feeds could be intercepted in much the same way as with the Predators, according to people familiar with the matter.


[From: DIY Drones]

Wednesday, December 16, 2009

VRbot Hardware Based Speech Recognition Module

The VRbot voice recognition system looks pretty good. It support multilingual speaker independent commands in American English, Italian, Japanese and German. Francophones will have to use the 32 user defined speaker dependent commands.

Built-in commands
action, move, turn, run, look, attack, stop, hello
left, right, up, down, forward, backward
0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10

The VRbot module supports 3.3-5V power, and comes with a microphone. The communications protocol is over TTL level serial and looks fairly easy to interface with a microcontroller. The demo videos give an extensive overview of working with the module and provide a good example of its real world performance.

CyPhy Works decloaking

iRobot Founder Helen Greiner's new startup CyPhy Works, formerly known as The Droid Works, is slowly coming out of stealth mode and MIT Technology Review has the scoop.

They have also started accepting resumes, which may be of interest to some of you.

Tuesday, December 15, 2009

Help wanted at Willow Garage

Willow Garage needs you help designing robot behaviors. These are physical gestures that robots can use to indicate desired human interactions such as needing assistance recharging and threatening bodily harm.

This video is an example of the behavior "Robot needs power badly".

I was having some video problem on Linux the first time I tried it but it seems to be resolved. I think the videos are supposed to only play once.

An example survey question
3. If you were the person depicted with the robot in the clip, what would you do immediately after seeing the robot do what happened in the clip?

Look for the E-Stop

Willow Garage plans to make information about the results of the study available for other robots to use. I think we need robot gestures for "I'm lost", "No network connection" and perhaps "sick" to indicate if a robot may be unsafe to approach.

Half Size/Full Speed Bee Micromouse

Bee is the half size younger sibling of the Tetra micromouse created by Kato-san. I think it's almost as fast as Tetra.

Bee Specs
top speed: 2000mm/s
top acceleration: 6500mm/s/s
top angular acceleration: 40000deg/s/s
turn speed: (90L)800mm/s, (90V)650mm/s, (180)760mm/s, (45)820mm/s, (135)730mm/s

4x Toshiba Photo Transistors ±10° TPS601A
4x Osram Opto 850 nm IR Emitters ±3° Beam Angle SFH4550
1x Epson Toyocom Gyro ±100°/s XV-3500CB
2x Nemicon Ultra Micro Encoders OMS-125-2T
2x Full-Bridge Motor Drivers ±2.8 A 36V A3950
1x ST Microelectronics ARM Cortex™-M3 STM32F103CBT6
2x 70mAh Zippy 20C discharge Lithium Polymer Batteries

Kato-san clearly spent hours and hours picking out those parts from Digikey. The motor drivers look to be a particularly good choice for smaller robots. The narrow beam angle on the IR emitters and photo transistors probably help prevent overhead lighting from interfering with the sensors and improve the accuracy.

This schematic shows Kato-sans amazing engineering skills. I especially like the use of the opamp for biasing the gyro signal.

Thanks again to Lem Fugitt of Robots Dreams for making us aware of these awesome robots.

Monday, December 14, 2009

Quadrotor Target tracking and path planning

The MIT team's paper from the international aerial robotics competition is also available.

The physical configuration of the stereo vision system and its integration with visual odometry for position estimation is particularly interesting.

TETRA Micromouse

If you haven't seen it already this video shows the amazing performance of the TETRA Micromouse at the 2009 All Japan Micromouse Competition.

Lem from robots dreams has an in-depth analysis of it's performance.

Updated 15 Dec 2009 6:08
Tetra Specs
top speed: 4300mm/s
top acceleration: 15000mm/s/s
top angular acceleration: 60000deg/s/s
turn speed: (90L)1600mm/s, (90V)1350mm/s, (180)1400mm/s, (45)1600mm/s, (135)1350mm/s

Saturday, December 12, 2009

Ping))) Sonar Mount

This is a mounting bracket that was designed to hold the Parallax Ping))) Sonar Sensor.

It is now available on Thingiverse, if you want to print your own.

Friday, December 11, 2009

3-Axis Geomagnetic Sensor

ALPS has a new Geomagnetic sensor that looks useful for robotics by providing not only compass information but also 3 axis angular velocity measurement. It looks like the gyroscopic information is synthesized in software from the magnetic field information as opposed to how MEMS gyros normally work. Measuring 2.5 mm x 2.5mm x 0.7mm, the price for small quantities appears to be 1000 Yen per chip.

It will be interesting to see how this could be integrated into a system in a way that compares to something like the ADIS16405, High Precision Tri-Axis Gyroscope, Accelerometer, Magnetometer from Analog Devices, for robotics and unmanned systems applications.

[From: Robonable]

Thursday, December 10, 2009

More on speech recognition

There are a few options for controlling your robot(s) with voice recognition.

Sensory Inc.
now has development kits available for an integrated hardware solution which solves the problem of licensing a corpus for low volume products. DynaSpeak also looks interesting as a closed source commercial software solution since claims it can run on a 200MHz StrongArm Processor running Linux.

ASR Labs vende um produto para o econhecimento de Fala para Português Brasileiro e Inglês Americano.

That said, I can't wait for the day my robot can speak and understand more languages that I can.

On the open source side of things many options still suffer from poor speaker independent recognition, but things are improving. VoxForge has made it even easier to contribute your voice to the open source speech recognition effort. As more people contribute their voices the quality of speech recognition will improve and it will also help computer science graduate students working on various voice recognition theses.

The important part is that by contributing your voice to VoxForge, you are helping robots understand what humans are saying about them. On second thought, maybe this isn't a good idea.

At least the text to speech side works pretty well so we can understand when our robots are angry unhappy.

Wednesday, December 9, 2009

Step 1: Identify Target Friend

This video shows the PR2 robot hunting following its natural prey friend the grad student.

Tuesday, December 8, 2009

Upgrade: LED Hexbug Hack

These photos should show how you can hack your own hexbug to add an LED.

The basic idea was to add a simple feature so the HEXBUGS can play in the dark. Unfortunately the power supply for the hexbug is only 1.5 Volts which really gives you only about 1.3 Volts when the motor is running and the lowest forward voltage of any of the LEDs I have handy is 1.8 Volts. To produce the necessary voltage, I considered a few different solutions but the easiest to implement was just adding another 1.5 Volt battery in series for just the led.

1) First gently pry open the Hexbug. A small screwdriver may help.


2) Solder two wire wrap wires in parallel with the motor so that the switch turns off the led as well.

3) Using a small knife cut two notches so that the case fits back together cleanly.


4) Solder the wires to the extra battery to get 3 Volts and attach them to the LED. Check polarity. Use CA Glue to attach the surface mount LED to the front of the robot.

5) The battery can be taped on to the back and adjusted for balance. In the future I may try to find smaller batteries that can fit inside the hexbug or blink the LEDs with a storage capacitor.


6) Finished!!

Here is the video of it in action.

[Buy Them Here]

Monday, December 7, 2009

ROBO-ONE: Gundam vs. Gundam

Here is some video footage of a recent ROBO-ONE battle. Holypong's Gundam performs an amazing decapitation attack at the beginning. In the end however, it looks like the Gundam had not been fully recalibrated for earth's gravity having recently returned from space. The robot is currently undergoing maintenance at an undisclosed location.

Vibrobot How-to

For those of you who like to build your own. Here is a cool how-to with schematics for building your own BEAM vibrobot robot from scratch.

Friday, December 4, 2009

Parametric Gears

Here are some nice parametric gears I found on Thingiverse. Various sizes and shapes can be parametrically generated using the provided OpenSCAD script. Another day, another step forward for open source hardware.

Spykee: Telepresense for kids

Erector Spykee looks interesting as low cost telepresence robot despite its flaws. It looks a little easier to modify than the Rovio since it is compatible with Erector (Meccano) sets.

The community support for the Spykee seems pretty good with some forums, a wiki and a something about a fuel cell powered Spykee. Since it runs Linux, I wonder if you could port ROS to it.

It also seems to be popular in France.

Thursday, December 3, 2009

ROS Robotics Framework

This is from a talk on ROS at IREX 2009.

It is important for the research and industrial robotics communities to work towards a modular system for connecting software and hardware. This will keep people from wasting time and effort reimplementing things like navigation algorithms over and over again just because the motor controllers have changed.

The ROS Robotics Framework aims to do this by being the "Linux of robotics".

Wednesday, December 2, 2009

Arduino + Netbook Robot

I really like the combination of using an Arduino microcontroller with a netbook. The netbook provides enough computational power to run things such as face detection, speech recogintion, mapping and other high level robotic tasks. The Arduino microcontroller, on the other hand, is perfect for real time control of the motors and sampling of sensor data on the robot. Maybe Dell should sell a Mini 9 with an Arduino built-in, similar to the old geekport.


The HEXBUG robots are pretty cute and occasionally give the impression of sentience. With a little bit of work you can upgrade the bug brain with a microcontroller.

The HEXBUG Nano is basically a pre-built and well refined bristlebot clone but unlike the bristlebot it is able to flip itself back over to avoid getting stuck. It does not appear to have any sensors or control and relies on random emergent behaviors to give the impression of intelligence. But, if someone gets me one as a present [hint] then I'll try to see if there is a way to steer them and maybe add some light sensors. Though I'm not sure how you would work out the differential equations to describe the motion induced by the oscillating weight attached to the motor.

The HEXBUG Nano Habitat Set looks like the robotic equivalent of an ant farm and could be used as evidence in your trial after our future robot overloads take control.

Tuesday, December 1, 2009

Finishing 3D Printed Prototypes

3D printers produce amazing prototypes for a relatively low cost. However the parts often have a surface finish that is less than ideal for market testing, investor demos and production one offs. The printed parts can be finished to look very similar to injection molded parts without the significant investment injection molding requires.

Step 1: Sand your parts with 120-150 grit  sand paper

Step 2: Paint your parts with an enamel paint or primer. The suggested drying times will usually be something strange like repaint in 1 hour or after 24 hours. These drying times should be followed closely to ensure proper curing of the resins in the paint. The time to cure the resins can be improved by baking the parts in a warm dry place.

Step 3: Sand your part using 240 grit sand paper followed by 400 grit. Until smooth. If it is not smooth before the final coat, if will not be smooth after.

Step 4: Repeat steps 2 and 3 until finished.

If you are impatient and do not let the paint properly dry, the results may be unsatisfactory. Resand and repaint until satisfied.

This is the finished case for a Gumstix Palo35 display board and Overo computer module.

The part is finished when you get tired of sanding or when you run out of paint.

If anyone is interested in buying a case for their Gumstix Palo35 or Palo43, send an email to iheartrobotics at g mail.