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Our PIC ”Kitchen Lab”. Who has said that PIC-processors aren’t Rocket Science ?. REXUS. R ocket-borne E xperiments for U niversity S tudents. ESRANGE Sweden mar 2010. Mission, deploy a web in space. Mission To deploy a net in zero gravity. What to do with a web in space?.
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Our PIC ”Kitchen Lab” Who has said that PIC-processors aren’tRocket Science ? William Sandqvist william@kth.se
REXUS Rocket-borne Experiments for University Students ESRANGE Sweden mar 2010 William Sandqvist william@kth.se
Mission, deploy a web in space Mission To deploy a net in zero gravity William Sandqvist william@kth.se
What to do with a web in space? • Could be used as an Antenna? • Could be a lightweight platform for miniature crawling construction robots? William Sandqvist william@kth.se
How to unfold a web in zero gravity? ? ( when Fuglesang isn’t there to help ) William Sandqvist william@kth.se
First: How to fold a web? Some Japanese origami is needed This is the Miura-Ori folding scheme From Mattias Gärdsback and Gunnar Tibert William Sandqvist william@kth.se
Scater spinning on ice Law of the Conservation of Angular Momentum Initial Unfold Rotation will slow down! William Sandqvist william@kth.se
The ”spinning scater principle” Rotate the hub with weights attached to the corners of the web, then the centrifugal force will unfold the web? Won’t Work! The ”spinning scater priciple” can’t unfold the net. If the initial rotational speed is to low, the final centrifugal forces won’t be strong enough to deploy the net. If the initial rotational speed is to high, the energy transfered from the hub to the net will cause oscillations – then the net will be tangled. William Sandqvist william@kth.se
Reaction wheel to ”help” the rotation The stabilizing rotation of the web centrifugal force Reaction wheel hub William Sandqvist william@kth.se
Controled unfolding Nice! William Sandqvist william@kth.se
Simulation of the reaction wheel motor voltage during controled unfolding Simplified control is possible! From Mattias Gärdsback and Gunnar Tibert William Sandqvist william@kth.se
The gyro Gyro to sense hub rotation Sensitivity: 5mV/ °/s 1 Hz (360°/s) 1.8 V0.1 Hz 0.2V0.01 Hz 0.02V William Sandqvist william@kth.se
Reaction wheel controler card With simplified control, one simple PIC Micro could do the job! Start now signal E [V] PIC Micro PWM Now ejected signal RWmotor DIR Gyro (x),( y), z,temperature Release the net signal William Sandqvist william@kth.se
First PICKit 2 and breadboard William Sandqvist william@kth.se
When the flywheel was lifted with a string everything worked! Zero gravity on earth! Zero gravity on earth? Problem: motor cold not move flywheel!The gravity caused friction in the bearings. William Sandqvist william@kth.se
Board layout, and manufacturing Our LKPF facility William Sandqvist william@kth.se
Sorry: We didn’t deliver a working board in time. (and there were other problems elsewhere) Wait for:Esrange Februari/March 2010 William Sandqvist william@kth.se
The Orion rocket No PIC-processor in space (this time) William Sandqvist william@kth.se
Circuitboard with testprogram A degree project was performed by student Andreas Svensson in order to assure that we in the future, given a second chance, have a board that works, Circuitboard and testprogram. a auto testm motor testg gyro testl led tests signal testwrite command: William Sandqvist william@kth.se
Demonstration with PICKit2 UART Tool a auto testm motor testg gyro testl led tests signal testwrite command: William Sandqvist william@kth.se
