A large ion beam figuring plant which can process up to 1.5m mirror in diameter has been developed. The plant adopts
five axes scanning mode. The mirror with which the five axes scanning system is set face to face is placed vertically
when working that can reduce the adverse effect of the flour dust to the mirror and the ion source. The mirror and the
five axes scanning system are installed on two doors respectively. The open-close type of the door is a hanging bridge
type. And the door will be horizontal when completely opening that will be convenient for installing the mirror and
maintaining the system. Two software which are used for calculating the dwell-time and controlling the five axes system
are programmed. The five axes system will always keep normal direction following when working.
Structured light system using a digital micro-mirror device (DMD) projector is increasingly used for a 3-D shape measurement because of its digital nature. When the DMD projector is used in phase measuring profilometer (PMP), the precision of profile measurement will increase with the precision of phase-shift increasing. But the non-sinusoidal nature of the projected fringe patterns causes significant phase measurement error and consequent shape measurement error. In the reality, we find that the non-sinusoidal effect is never caused by only one factor. A real measurement shows that it is a combination of influences by all effects, e.g., the object independent irradiance function, the nonlinear gamma curve of the projector, the spatio-temporal characteristic of DMD, etc. In view of the above factors, a comprehensive compensation method is proposed to compensate these factors for the 3D measurement. If the compensation is well accomplished, the measurement error can be reduced average 6 times. The experiment is carried out to demonstrate the validity of this technique.