Research On The Key Technology Of Precision Regulating System For Compton Light Source

Recently, with the aerospace industry rapid developing, the requirements for equipment increasing. X/γ-rays detector, as a kind of payload in space probe, plays an important role in many important applications. Before executing a task, the X/γ-rays detector should be calibrated on the earth. But the radioactive source existed can`t meet the requirement of accuracy. So it`s desired to seek a kind of γ-rays source that it`s energy monochromaticity is good, energy range is broad and peak energy is adjustable.Γ-rays are obtained from Compton Scattering, so it needs the laser and electron beam whose radius are both 20μm to make a high precision collision. After researching the domestic and foreign development present situation of MEMS, the paper puts forward that designing a set of precision regulating system to control the path of laser accurately.The laser and electron beam in Compton Scattering experiment is invisible. So the paper proposes to put a YAG fluorescent target in the setting collision position. It will appear two light spots after the laser and electron beam hitting the YAG fluorescent target. Change light path of the laser by precision regulating system, and then the position of light spot in the YAG fluorescent target will transform. By this way, the two spots can reach a demanded contact ratio.In order to realize accurate control of the laser`s light path, the positioning accuracy of laser mirror in the FSM system should be 6×10-4 degree. The paper choose Piezomotor to be actuator, and design frictionless, gapless and compact flexure hinges to be driving element, so to ensure the mechanical positioning accuracy.Because the radius of laser and electron beam are only 20μm,the paper puts forward to detect the position of electron beam `s and laser`s light spots in the YAG fluorescent target by high resolution CCD camera and microscope lens. The paper uses fuzzy-PID control algorithm to build close loop control system based on visual feedback, to adjust the position of the light spot rapidly, stably and accurately.The paper has analyzed the mechanism of precision regulating system by FEA, results shows that the max press and stroke meet requirements. Then analyzes the rotational stiffness error of flexure hinges caused by machining accuracy, compensates theoretical results by error data, and creates the transfer function of the control system, and do a simulation in Simulink to validate the feasibility of the system. At last, contrast the control effect of PID algorithm and fuzzy-PID algorithm through the experiment. Find out that fuzzy-PID algorithm is more adaptable, it`s overshoot is smaller, and is more stable in the state of equilibrium.