NI-Week 2010 Dart Demo
"Sisu Devices created one of the most engaging demos of the show this year which electrified the crowd and exceeded expectations."
John GraffVice President of MarketingNational Instruments"This demo was showcased in the NI Week Day 1 keynote and then was a "show stopper" and grabbed everyone's attention on the expo floor. Sisu Devices' NI product knowledge both in depth and in breadth is clearly displayed in the final product."
Devin ShelgrenEvents Logistics (DemoDogs) and European Demo Facility ManagerNational Instruments
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Vision
The system uses two, Basler Scout, Gig-E cameras located at the bottom left and right hand corners of the demo to detect the dart. A stereo camera algorithm triangulates the XYZ position of the flying dart in 3D space.
The cameras are triggered at 110 frames per second each! This allows for about 9 pictures of the dart as it travels beneath the light hood which is fitted with engineering grade retro-reflective material. This material from Nikkalite lights up like an Austin sidewalk in August when exposed to the bright ring lights from Advanced Illumination. The dart is silhouetted against this brilliant background and motion commands are sent after acquiring about 3 of the 9 frames. Adjustments are continually made until the dart impacts the target.
Motion
Two AKM 44-series Kollmorgen motors from Danaher Motion are used in combination with EtherCAT AKD drives. The system seamlessly integrates with NI SoftMotion 2010 from National Instruments. A 5:1 gear head was used to create a more appropriate inertia mismatch. The speed of the dart allowed for less than 100 mSec to move the target 0.5 m! Motion simulations were performed in SolidWorks to correctly determine the torque and load conditions of the arms. The arms were optimized for strength and reduced mass. Bearings from Igus were used at the pivot points to provide light weight, low friction, high speed joints.
Time
If you attended the NI-Week keynote on Tuesday morning, you know that it was all about "time." Special sensors on this demo measured the speed at which the dart left the gun, and the time it took the dart to travel to the target. This was performed by adding an optical sensor to the gun and a conductive fabric sensor to the target. Time was synchronized between the cRIO controller (wired to the gun), and the NI Industrial Controller (wired to the target sensor) using the new NI TimeSync, 1588 product. This new product from NI allows sub-millisecond synchronization of real time targets over Ethernet.
Sound
One thing that really made this demo come alive was the sound. While the shooter has target practice, they are serenaded with "The Good the Bad and the Ugly," "Star Wars" theme song, and "Eye of the Tiger." When a dart impacts the target, the shooter is rewarded with sounds of bullet ricochets, light saber clashes, or punching sound effects depending on the theme song.
Schedule
Sisu Devices provided NI with concepts, created computer animations for NI approval, designed, built, and programmed this machine in two months! The customer (National Instruments) was obviously delighted with the finished product.
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