Jun 30, 2011
Blogs
Since publication, on June 13, 2011, the TILTO's video has been reproduced thousands of times and posted in the most infamous tech blogs all around the planet, in english, spanish, polish, swedish, and who knows what else!
Jun 28, 2011
Very First Real Test
Finally, on Sunday June 12, 2011, the Tilto had its first street unexpectedlysurprisingly good, that after so much effort gave me lots of happiness.
This was only the first test of Tilto and there is still too much to improve, but the idea I thought over a year ago is now working.
Mounting the Beast
When the power drivers were tested ("almost" without producing magic smoke during the tests), I went to buy the hardware.
I worked a little in the workshop of my friend Nicolás and a little more in my apartment, and before long I built a simple structure and started the first Tilto's tests:
At this point I faced the most difficult problem: The electric motors (donated by my new friend Gustavo) are previously owned and a little worn, and have too much backlash in the gears of the gear boxes. This produces a dead zone where the system has no control and provokes strong shocks that destabilize the entire unit.
I spent an entire week thinking and testing mechanical solutions, until one morning I woke up with a simple software based solution.
It worked pretty well, and I finally mounted the Tilto beast!
Power Drivers
Happy with the performance of the "brain" I went to the design and construction of the motor driver modules.
The design is made from scratch, using components that could be available in my city (Buenos Aires , Argentina
The result were two switching circuits, in two homemade boards full of MOSFET power transistors, capable of handling nearly 10 times the current actually needed.
The Software
The next step was to start writing the software.
For that I studied tons of similar projects and had to refresh my coding competence.
I had also to update all the software used to write, compile, simulate, etc., and practically had to learn again to use embedded microprocessors.
The result was a long piece of software, coded in C for a 16F877 microprocesor from the PIC family (they are obsolete, but I had a couple in an old drawer...).
I disregarded the Kalman Filter in favor of Complementary Filters to fusion the accelerators and gyroscopes data, to get the actual tilting angles, free from noise (kind of).
Then a PID (Proportional, Integral, Derivative) algorithm produce the PWM (Pulse Width Modulation) signals to be sent to the motor drivers.
When the software was ready enough I bought a 5 degree of freedom (3 accelerometers + 2 gyros) IMU (Inertial Measurement unit) and mounted it together with the microprocessor on a crappy brown perf board, as can be seen in the videos:
Yes, it is true that in the last video it shows a delayed response, but that is due to the lack of adjustment of the software's constants and is already fixed.
Patent Application
To be brief, as I already said I spent several months drafting the Patent Application, that was filed in December 2010 and can be downloaded from this LINK.
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