Posts with «brushless» label

Balancing Robot Needs Innovative Controller and Motor

A self-balancing robot is a great way to get introduced to control theory and robotics in general. The ability for a robot to sense its position and its current set of circumstances and then to make a proportional response to accomplish its goal is key to all robotics. While hobby robots might use cheap servos or brushed motors, for any more advanced balancing robot you might want to reach for a brushless DC motor and a new fully open-source controller.

The main problem with brushless DC motors is that they don’t perform very well at low velocities. To combat this downside, there are a large number of specialized controllers on the market that can help mitigate their behavior. Until now, all of these controllers have been locked down and proprietary. SmoothControl is looking to create a fully open source design for these motors, and they look like they have a pretty good start. The controller is designed to run on the ubiquitous ATmega32U4 with an open source 3-phase driver board. They are currently using these boards with two specific motors but plan to also support more motors as the project grows.

We’ve seen projects before that detail why brushless motors are difficult to deal with, so an open source driver for brushless DC motors that does the work for us seems appealing. There are lots of applications for brushless DC motors outside of robots where a controller like this could be useful as well, such as driving an airplane’s propeller.


Filed under: robots hacks

Arduino based Quadrotor on a PCB

There are many Quadrotor Projects out there. But, they require a hobbyist to deal with the Frame Designing (Mechanical), a bit of Microcontroller knowledge as well as dealing with the Motor Control (Power Electronics). You may purchase a commercial Radio and a readymade Kit for flying. But, to Do-It-Yourself, is an achievement in itself.

Here is a picture of a Quadrotor designed by Shane Colton using Arduino Pro mini as its flying brain. Shane is a Ph.D Student at Massachusetts Institute of Technology. On being asked about the Project, he replied:

I heard about Arduino some time in 2007/2008 and have used it for a few projects since then. I built the quadrotor for fun / hobby (not related to research). I wanted to build my own (quadrotor) from scratch because I could integrate all the parts onto a single circuit board, and because I like designing the control system myself.

When he says he build the quad from scratch, he literally did it. Neither did he use any commercially available Radio Control, nor did he use any Electronic Speed Controllers (ESCs). Instead he went for creating his own Brushless DC Motor Controller, that too, on the same PCB which acts as the Quadrotor’s Frame.

He spent a lot of time researching about propellor balancing as well as vibrations in the PCB. Here is a video:

Now, that is called a hobby. In a detailed Instructable, he shows how you too can build a Quadrotor on a PCB. He has a project blog at http://scolton.blogspot.com with documentation on most of his projects.

Enjoy the ride:

Arduino Blog 06 Jun 07:47