International Telemetering Conference Proceedings / October 23-26, 2000 / Town & Country Hotel and Conference Center, San Diego, California / An advanced electro-optic hybrid rotary joint (EOHRJ) has been developed in Phase II of an AF SBIR effort with Physical Optics Corporation (POC) to replace cable wrap structure for multi-channel rotation-to-fixed (RTF) signal transmission. The EOHRJ meets AFFTC and other range special needs with a generic, high performance, rotary joint solution. At the moment, we have successfully installed and tested the EOHRJ on our KTM tracker system with the following capabilities: 1) able to accommodate hundreds of transmission channels, including electrical power, control, feedback, and low-speed signals; 2) able to accommodate multiple channel, high data rate (over gigabits per second), and bi-directional signal transmission; 3) able to be reliable for harsh environmental operation, adaptive to stringent sized requirement, and accommodating existing electrical and mechanical interfaces. The completed EOHRJ contains three uniquely integrated functional rings. The first and the outmost one is power ring, which provides RTF transmission channels for over 50 high voltage and high current channels. The second and the middle one is low speed electrical signal ring, which provides RTF transmission for over hundred control, feedback, and low speed data signals. The third and the inmost one is optical fiber slip ring, which, incorporating with current advanced signal multiplexing technologies (either time division or wavelength division multiplexing ) is able to provide multiple channel, high data rate, and bi-directional signal transmission. At the moment, the prototype module of the tree-layer EOHRJ has been successfully assembled in Air Force’s tracker system, and is providing a satisfactory performance. This paper presents our joint work on this project.

Detta arbete utfördes på vridledsmodulen för handhållna kameror från T-serien hos företaget FLIR. Vridledsmodulen används för att hålla uppe objektivet och reglerar vinkeln på detta i jämförelse med resten av kameran. FLIR hade tidigare ett flertal lösningar för olika kameramodeller och dessa hade individuella problem när det kom till kvalitet, toleranser och hållbarhet. De tidigare lösningarna skilde sig i vilka komponenter som används och vilket vridmoment som krävs från användaren vid bruk. Företaget sökte en ny lösning för vridledsmodulen; en lösning som var skalbar. Detta innebar att den nya modulen skulle kunna användas i flera kameramodeller med olika användarmoment och olika objektiv med varierande vikt. Användarmomentet skulle kvantifieras genom att utvärdera befintliga lösningar; de funna värdena skulle sedan användas för att finna en ny lösning. Dimensionerna på modulen skulle väljas med hänsyn till dimensionerna på de tidigare lösningarna och gränssnittet mot kamerahuset. I början av projektet utfördes en förstudie genom att titta på tidigare lösningar gjorda av FLIR för att formulera krav på produkten. De verktyg som användes för detta var MATLAB för beräkningar, SolidWorks för CAD och utrustning från verkstaden för att manuellt mäta momentet. För att börja formulera koncept gjordes en brainstorm där de första koncepten förklarades genom skisser, och senare med CAD gjorda i SolidWork. Dessa koncept beräknades på genom att använda MATLAB för att hitta rätt dimensioner och komponenter. Koncepten diskuterades genom att låta berörda parter ge feedback under planerade möten. En Pugh’s matris användes för att utvärdera koncepten emot varandra, för att välja slutkoncept. De slutgiltiga koncepten var av två olika modeller. Det ena kontrollerades genom dimensioner och stålkulor, styrda av kompressionsfjädrar, som klickade i spår i en ytterring. Det andra styrdes endast genom friktionen mellan två ytor som var i kontakt med varandra under lasten från kompressionsfjädrar, där det då inte fanns distinkta klicklägen. Avsikten var att dessa två koncept skulle ha samma moment och att de skulle vara skalbara på samma sätt; genom olika förspänning av fjädrarna i applikationen. / This work was done on the rotary joint module of handheld cameras in the T-series made by the company FLIR. The rotary joint module holds the lens and controls the angle in relation to the rest of the camera. FLIR’s current solutions for the rotary joint had various module solutions for different camera models and the solutions have individual problems in quality, tolerances and durability. The current solutions differ in which components that are used, in dimensions and what torque is required by the user. The company was looking for a new solution for the rotary joint module; a solution with scalability. This means that the new module were to fit in several camera models with different torques and with lenses of different weight. The torque needed by the user would be quantified by evaluating solutions used today, where these values would be applied when finding a new solution. The dimensions of the module would be in consideration to the dimensions of the earlier solutions and to the interface between the joint and the camera. In the beginning of the project a pre study was made by looking at the current solutions made by FLIR to form requirements. The tools used for this were MATLAB for calculations, SolidWorks for CAD drawings and workshop tools for manual measurements of the torque. To start forming concepts solving the problem a brainstorm was performed where the ideas were visualized using sketches, and later CAD drawings using SolidWorks. These concepts were calculated using MATLAB to find the right dimensions and components. The concepts were discussed using meetings with interested parties, to get feedback on the work and sort out the better concepts. A Pugh’s matrix was used to evaluate the concepts against each other. The final concepts were of two different models; one controlled by dimensions and steel balls, connected to compression springs, clicking into grooves, and the other controlled merely by the friction between two surfaces provided under load from compression springs, where there were no actual click positions. The intention was that these two would have the same torque and they were scalable in the same way; by pre-tensioning the springs in the application to give different loads.

International Telemetering Conference Proceedings / October 25-28, 1999 / Riviera Hotel and Convention Center, Las Vegas, Nevada / Current ground-based tracking systems at the DoD test and training ranges require transmission of a variety of signals from rotating platform to fixed control and process center. Implementation of commercial off the shelf (COTS) solution for transmitting high-speed, multiple-channel data signals over a rotational platform prompt the development of an advanced electro-optic hybrid rotating-to-fixed information transmission technology. Based on current demand, an Air Force-sponsored Small Business Innovative Research (SBIR) contract has been awarded to Physical Optics Corporation (POC) to modify existing tracking mounts with a unique electro-optic hybrid rotary joint (EOHRJ). The EOHRJ under current development is expected to provide the following features: 1) include a specially designed electrical slip-ring, which is able to accommodate hundreds of transmission channels, including electrical power, control, feedback, and low-speed data signals; 2) include an optical fiber slip-ring which, by incorporating with electrical time division mulitplexing (TDM) and optical wavelength division multiplexing (WDM) technologies, is able to provide multiple channel, high data rate (over gigabits per second), and bi-directional signal transmission; and 3) is designed to be reliable for harsh environmental operation, adaptive to stringent size requirement, and accommodating to existing electrical and mechanical interfaces. Besides the military use, other possible commercial applications include on board monitoring of satellite spinners, surveillance systems, instrumentation and multi spectral vision systems, emergency/medical instruments, remote sensing, and robotics.