Robot Takes Voice Commands Via Open Source CSR

This is Chippu, a robot that [Achu] has been working on for some time. His most recent addition was to give the robot the ability to respond to voice commands. This is accomplished using a variation of the open source Continuous Speech Recognition package called Julius.

The package depends on two main parts, a set of acoustic models which let it match incoming sounds and a reference library of grammar which is built from those sounds. [Achu] published another post which goes into detail about using Julius on a Linux box. It seems like this is possible with less robust hardware (ie: on an embedded system) if you narrow down the number of acoustic and grammer models that need to be matched.

For now, Chippu is getting commands from a computer that runs the CSR. But this was only used as a proof-of-concept and [Achu] plans to transition the bot over to smaller hardware like the BeagleBoard.

Check out the demonstration of Chippu responding to voice commands in the video after the break.

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Treaded Robot Modified For Stair Climbing

[Mike Li] is showing of his stair climbing robot. It’s a bot that cruises around on a pair of tank treads, but some interesting modifications gave him the traction needed to ascend a flight of stairs without slipping backward.

The image above shows this process in great detail. You can see the unaltered treads leaving the top of the image. In the foreground, strips of rubber-backed rug add some sticking power to the otherwise smooth surface. To really stop the bot from slipping, segments of CAT5 cable have been screwed to the tread at regular intervals, holding the carpeting tightly in the process.

You can see in the video after the break the little robot has no problem with rough terrain. The design was inspired by the iRobot Packbot which has a set of treaded appendages sticking off the front end. These ensure that the vertical face of an obstacle, such as the beginnings of a staircase, can still be reached by the main set of treads.

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Giving The Hexbug Spider Freedom To Explore On Its Own

hexbug-hack

[Eric Gregori] recently spent some time messing around with a Hexbug Spider, and wrote in to share some modifications he made to the toy. In its unaltered form the robot can be controlled remotely, and while it’s fun to play with, the excitement is short lived. Using a TI MSP430 along with a small motor controller kit he put together, he gave the Hexbug a bit more personality.

The kit is really just a simple board used for mounting the MSP430 and FAN8200 motor driver, along with an IR emitter/sensor pair. It would be easy enough to put something similar together yourself, though if you are looking for a protoboard/deadbug/PCB etching-free solution, his Spider Hack kit is a quick and easy solution.

[Eric’s] walkthrough shows how to disassemble the Hexbug, and details which components need alterations before the controller board can be properly mounted. A few soldered wires later, the toy is ready to be reprogrammed, a process [Eric] carries out using the Launchpad board from which he lifted the MSP430.

As you can see in the videos below, calling the robot autonomous might be a bit of a stretch (I don’t see it walking to the kitchen to make me a sandwich), but it can navigate and avoid objects with ease.

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Line-follower Is An Homage To [Homer]; Plans To Infringe Copyrights

The Chief Knock-a-Homer robot is [Psycho Freaky’s] shout out to The Simpsons. The robot design appeared in an episode where [Homer] built [Bart] a fighting robot. Since he’s not robot builder, [Homer] actually climbed inside the shell and dished out sweet vengeance while suffering some severe injuries at the same time.

But [Psycho] has the skills necessary to make this autonomous and keep it looking just like the TV show at the same time. He has a friend with a CNC mill, and used it to cut out case parts from Masonite which were assembled with hot glue. A pair of small servos drive two wheels at the rear of the base, with a ball-bearing universal wheel centered in the front. There are also two downward-pointing sensors which lend it the ability to follow a line as seen in the video after the break.

We love the paint job, it really polishes the look. But [Pyscho] isn’t quite done yet. He plans to add an audio circuit that will give the robot the ability to play back classic sound clips.

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Easy Camera Tracking With A Quadrocopter

[DJ Sures] has been pulling all-nighters lately to get his AR Drone Parrot build off the ground. Now that it’s up and flying around, he managed to get it to follow objects around the room using on board cameras.

For the build, [DJ Sures] used the AR Drone ‘flying video game’ quadrocopter. This toy has two on board cameras that can viewed over wifi. All that’s needed is some interesting software to make things fun. The camera tracking of EZ-Builder software was brought into the mix so the AR Drone can be controlled via object or speech recognition, wiimotes, tablets, or terminals.

[DJ Sures] has come up with some slightly terrifying awesome builds like a Bluetooth Teddy Ruxpin, realistic Wall-E, and an awesome Omnibot 2000 refurb. This is his first flying hack, and the first to fully exploit the camera tracking of the EZ-Builder software. Check out [Sures]’ copter following him around a room after the break.

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Neural Networks Control A Toy Car

After taking the Stanford Machine Learning class offered over the Internet last year, [David Singleton] thought he could build something really cool. We have to admit that he nailed it with his neural network controlled car. There’s not much to the build; it’s just an Android phone, an Arduino and a toy car. The machine learning part of this build really makes it special.

A neural network takes a whole bunch of inputs and represents them as a node in a network. Each node in [Davids]’s input layer corresponds to a pixel retrieved from his phone’s camera. All the inputs of the input layer are connected to 64 nodes in the ‘hidden layer’. The nodes in the hidden layer are connected to the four output nodes, namely left, right, forward and reverse.

After training the network and weighting all the connections, [David] got a toy car to drive around a track. Weird, but it works. All the code is up on github, so feel free to take a look behind the inner machinations of a neural net. Of course, you could check out the video of [David]’s car in action after the break.

EDIT: We originally credited [icebrain] as the author. Our bad, and we hope [David] doesn’t hate us now.

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Easy Rotary Encoding For Your Projects

Want to monitor how much a wheel has turned in your project? Then you need a rotary encoder! Here’s a way to add rotary encoding without changing the mounting method of your wheels (translated). [Jorge] added it as a way to improve the functionality of this line-following robot. It uses a paper encoder wheel which is monitored by an optical sensor.

The paper wheel consists of alternating white and black pie pieces. You can make this with a felt-tipped marker, or use a tool like the one we featured a couple of years ago to print out a disc rendered to your own specifications. This is glued to the inside of the wheel and monitored by a CNY70 reflective sensor (the same one used in that electric keyboard retrofit).

The homemade board which holds the sensor can be seen mounted on top of each wheel’s motor. It requires three wires, voltage, ground, and data. The data line is connected to the output of the phototransistor in the CNY70 package so it can be used with a microcontroller interrupt for easy integration with the firmware driving the robot.

[Jorge] goes into some detail about how the added data helps to improve the speed performance seen in the clip after the break.

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