Quantum absolute gravimeter

Abstract

The invention discloses a quantum absolute gravimeter, which comprises a control system, a laser system and a probe system which are connected with one another through electric wires and / or optical fibers, the light path switch is arranged on a light emitting path of the laser system and comprises a power source, a control assembly and an execution assembly, the power source, the control assembly and the execution assembly are connected with one another, and the execution assembly is arranged on one side of the light emitting path of the laser system. The execution assembly comprises a light blocking part and a stepping motor connected with the light blocking part and used for driving the light blocking part to rotate so as to open or close a light path, the stepping motor comprises a rotor and at least a first winding and a second winding which are arranged in a certain circumferential direction of the outer side of the rotor, and the control assembly is connected with the first winding and the second winding. The stepping motor is driven to rotate by controlling the direction and the size of current in the first winding and the second winding, so that the light blocking component blocks or avoids light. The gravimeter can achieve the quick switching-on or switching-off of the laser band.

Description

technical field [0001] The invention relates to a gravimetric measuring device, in particular to a quantum absolute gravimeter capable of realizing rapid opening and closing of an optical path switch. Background technique [0002] The optical path switch is generally used in the switch control of the laser beam. By rotating the shutter to the designated position, the beam can be completely turned off, so as to achieve the controllable switch of the beam in the optical path. With the miniaturization of the optical path, the mechanical shutter generally needs to have the characteristics of small size, low noise, fast response, and fast and accurate shutdown. [0003] The optical switch is usually composed of three parts: a light barrier, a stepping motor and a drive circuit. The function of the light blocking sheet is to block light. By fixing the light blocking sheet on the rotor of the stepping motor, when the rotor of the stepping motor rotates, the light blocking sheet is...

AI Technical Summary

Problems solved by technology

It is common that the moment of inertia of the stepping motor rotor of this volume is less than 10 gm^2, while the moment of inertia of the light blocking sheet is greater than that of the stepping motor rotor itself. In this way, when the moment of inertia of the light blocking sheet is too large, the traditional fine The split-drive gait will cause the jitter caused by the inertia to continue to move forward after the light baffle reaches the designated position

For example: for a common 20-step stepper motor that meets the volume requirements (18 degrees for a single step, the torque is about 1mNm), after installing the light barrier, the single-step step time is about 4ms, and the time for two steps to 36 degrees It is about 6ms, but due to the inertia, it will swing back and forth around this angle, and the final stop time is about 100ms. The maximum angle of the initial overshoot can reach more than 18 degrees. Overshoot will affect the light blocking effect. Generally, the mechanical shutter can respond quickly. The shape of the designed light barrier is slightly larger than the spot size, and once the overshoot exceeds 2-3 degrees, it cannot be turned off, so the traditional subdivision drive cannot be applied to the miniaturized optical path that requires fast optical switches

Images