Last week was full of positive happenings for the ARCADE project. Among these the inclinometer acceptance test was successfully performed! The Posital Accelens ACS-080 inclinometer will provide the ACS with the gondola attitude information allowing to reject the consequent disturbances outside the feedback loop. A picture of the x-axis inclinometer response compared to the ideal values follows.
It’s been a hard working couple of weeks in the lab! We performed lots of testing on LED and photodiodes for the IR sensor, and had some troubles too (never trust a datasheet!!!). Anyways, it seems we got some reasonable results on both the polar response of the photodiode and the LED beam shape, and we are now processing the data to validate the model of the sensor. Stay tuned for updates! Meanwhile, here are some pictures (note the telescope support we used to rotate the LED and the receiver…)
Sorry for the delay from the last post, we know everybody can’t wait to know how was our CDR. Actually it was good! There were of course many remarks and suggestions about the various systems, but there were not serious concerns. You know what I mean, the “you will not fly with such a thing” ones.
Also during the CDR, a big piece of advice was given us about the yaw backup motor, and that helped to save, well, about 4000€ for a strange hollow-shaft defense-grade motor that was included in our design!
Finally, the MINI Arcade received its honors too!
BUT NOW. Now it is time really to build what, up to now, is only drawn, both on sheets and into our heads. We talked so much about it, that it quite seemed a real thing, at least it is so real in our dreams. Devices, materials, quite everything has been ordered and something has also arrived! Not much time will take until we fasten the first screw!
Stay tuned for what we have talked until now. Becoming real.
The second Arcade Crew has finally met their Crew One companions at Mitchbi Hotel, in Noordwijk. Looking for the good vibe for a great CDR!
Catch ya tomorrow,
Here we present the “making of” Sperimentando 2011! The hard work to print our big poster (hard work for the plotter actually ) and the construction of arcade interactive little version! Again, come to see us and have a try to dock!
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“Venghino signori, venghino!”
ARCADE EXPERIMENT will be presented during the “Sperimentando” Exhibition in PADOVA. A travel between science, physics and chemistry!
ARCADE TEAM will be there to explain the concept, the project and the adventure of ARCADE. INTERACTIVE! Don’t miss the “Lil Bro” interactive version of ARCADE EXPERIMENT!!
WHO’S FAR FROM PADOVA: Don’t miss the photos of the exhibition!! WHO’S NEAR PADOVA: Don’t miss at all!
Here’s the official ad
Here are some CAD drawings of ARCADE’sa reaction wheel as it looks right now. It is almost the final version, but it might undergo some minor changes. The encoder (black) is visible attached to the lower side of the motor.
The selected motor is the DPM 57BL54 and we are already processing the documentation for order and purchase.
Our logo was updated to version 1.1, in order to truly represent a Tetris screenshot and… well, to make Koen happy.
The following figure better shows how it changed.
From navigation systems to cell phones, nowadays gyroscopes are widely used in consumer electronics. Do you want to know in which direction you’re travelling? All you need is a small piece of semiconductor that makes up a Micro Electro Mechanical System Gyroscope (MEMS gyro for insiders) with vibrating structure. Actually these devices were designed for aerospace navigation. This is why we are going have one of them as part of our navigation system. With no need for external reference points or radio signals, that will be the most independent and reliable attitude measurement device we could use.
We selected an industrial grade on-chip MEMS gyro from Sensonor Technologies AS that pits out its data through an SPI interface. A CanOPEN-enabled PIC microcontroller acquires everyhing and the play is done! We are ready to get connected to the onboard experiment bus.
Up to now, from the electrical and communication point of view, everything seems to work fine. We will now struggle with the problems of calibrating the gyro and squeeze out as high as possible precision with as low as possible drift. This powerful, quickly built-up calibration facility will help us!
TRIVIA: How precise can ever be a gyro, measuring direction of a vehicle, is the earth itself spins about 2,5° each 10 minutes?
A simple apparatus to perform tests at subsystem level will be ready by next week… here it is how it will look like