Abstract
The dynamic pattern generator of resolution test target is widely used to evaluate the imaging
quality of the optical system. The dynamic pattern generator is composed of resolution test target and
linear motion device and it can provide uniform motion within 400 millimeters. The resolution test
target is photoengraved on the demands of photoelectric detection system and their patterns are
different to be replaced. The length of the resolution test targets are specially designed to reduce the
difficulty of the time system synchronism. The linear motion device is made of linear motor servo
system. It can implement high speed, high precision and reliable motion. The servo system is designed
with current loop, speed loop and position loop. The current loop and the speed loop are the inner
control loops of the servo system and they can compensate the influence of the power fluctuation and
nonlinear, uncertain factors to lessen the burden of the main loop. The inner loop employs proportion
and integration (PI) algorithm without derivation feedback. The position loop, which belongs to the
outer control loop, adopts proportion, integration and derivation (PID) algorithm and forward feedback
algorithm. The Hall sensors are feedbacks of the current loop, the grating rule is the feedback for both
the speed loop and position loop. The servo system is designed for the speed stability, so the speed is
the control goal. Especially, control of high speed and low speed is implemented by speed and
acceleration forward feedback. The servo system can get the precision of 1%.
