Life is a game, take it seriously

Archive for January, 2013|Monthly archive page

Light Weighted Vision Algorithms for a Light Weighted Aerial Vehicle

In Computer Vision, Robotics on January 15, 2013 at 10:50 pm

by Gooly (Li Yang Ku)

Recently, light weighted quadrotors that equip a camera like the AR Drone becomes cheap and interesting enough to be used in research even for poor students. By combining vision algorithms with a quadrotor you can really expand your imagination even to robot fishing.

quadrotor fishing

SLAM (Simultaneous Localization and Mapping) is a pretty hot topic in recent years; since in many situations a detailed map is not available for robots, it would be largely preferred if a robot could navigate in an unknown environment and  draw the map itself like how we humans do. Previously most SLAM researches use mobile robots with a laser scanner that builds up a decent map combining laser result with dead reckoning. However, a laser scanner weighs quite a lot and is not ideal to be mounted on a light weighted aerial vehicle. This is where visual SLAM take place. Visual SLAM is the name for all SLAM techniques that uses mainly visual inputs. (Mostly monocular camera only)

One of the early works of visual SLAM is MonoSLAM, which is done in Oxford. The video above shows how a 3D map is built by recognizing relative position of features merely using  a 2D camera. PTAM further expands this concept and uses 2 threads to improve performance. They provide open sourced codes on their website and was widely tested. The code was further ported to ROS by ETH Zurich and tested in the European SFly project on a few UAVs.

ROS also has a quadrotor simulator package where you can test your algorithms before crashing your real quadrotor.

All the publications and websites you should know about quadrotors are organized here.

Organizing Publications Visually: EatPaper

In Paper Talk, Serious Stuffs on January 13, 2013 at 2:44 pm

by Gooly (Li Yang Ku)

I always hoped that there would be a good app to organize the papers I read and show it graphically. I did Google for it but couldn’t find one that fits my need, so I started to build one about a year ago ( I stopped working on it several times for various reasons but now it’s finally functional (not perfect, but enough for now). The website functions a little bit like Pinterest, we both use bookmarklet, a website book mark that executes javascript, to fetch your current webpage. So the following are the typical steps to use EatPaper.

1. Search on Google scholar.

2. Click the bookmark button I made. (You can get the button by clicking “Add a Node” in

3. A dialog pops up and you can store the publication information you found as a node in your graph.

I also made a Chrome extension that has the exact same function.

The website is built using Google App Engine + Google Web Toolkit. If it turns out to be a little bit slow occasionally, please be patient; I have to admit that I don’t have any funding and only pay the minimum amount needed to host the server. Please share it to your friends if you like it. I probably can get more resources if more people use it.

You can leave a message here if you have any opinions, problems or found a bug.