Implementary scheme of parallel controllable optical fiber positioning system for LAMOST

The aims of LAMOST((1))(Large Area Multi-Object Fiber Spectroscope Telescope) optical fibers positioning system is carrying out 4000 fibers minutely position quickly on the focal plane plate. Base on the dividing domain, we are putting forward parallel controllable optical fiber positioning system, this system consists of several parts as follows: In the focal plate of LAMOST, A aluminous alloy plate with plate diameter 1.75 m, globe radius is 20m. Over 4000 holes are bored on the focal plate; one optical fiber positioning unit of double revolving freedom device is inserted in each holes of focal plate, it is drived by two micro-stepping motor and positioning one fiber-end, focal plate is sustained by 8 steel tubes on the focal mechanical framework; for driving 8000 stepping motors, a control system is needed; and a measuring system with 4K surface CCD is used to calibrate the fiber's position, besides a few accessorial devices for example 4000 wire and fiber setting up need to plan elaborately, According to plan, parallel controllable fiber positioning system will be made in the next three years.