Laser speedometer is the pivotal equipment in the process of setting up stream AGC control system,but the principle of laser speedometer based on double velocity of light and double scattering doppler technology has never been reported.

Existing calibration methods of laser speedometer are summed up and one new calibration method and instrument with simulant target is put forward in this paper.

The reserch of pulse-semiconductor laser velocimeter;

In the control system for skin pass mill elongation,the measuring devices in common use are pulse generator and laser velocimeter,of which the control accuracy of the laser velocimeter is higher.

This paper introduces the operation principle of laser velometer,expounds the control method in AGC system of double stand reversing cold rolling mill,analyzes each control algorithm of AGC system,and describs the composition and characteristics of each control section.