| The swing scanning mode infrared earth sensor is a component located onman-made earth satellite for measuring the attitude deviation (the angledeviation between the baseline of pointing to earth and the line of satellitelinking with the center of the earth) between the satellite body and the earth.It provides the reference of pointing to the earth for antenna oncommunication satellite, in addition, the infrared earth sensor takes on somefunctions of capturing the earth in the course of satellite launching,ascertaining the attitude of satellite in transition orbit. The accuracy ofcalibration test on earth surface for infrared earth sensor will directly affectthe working accuracy for satellite working in orbit.Scanning mirror is a key swing component for the swing scanning modeinfrared earth sensor, its performance directly effects the accuracy andreliability of the whole satellite, the measurement of its tilt angle and swingfrequency is all along the technique difficult problem which is expected tosettled urgently. On the research of measurement technology for swingamplitude of scanning mirror, based on laser technology, CCD probingtechnology and computer technology, a method of laser real-time dynamical,non-contact and automatic measurement for tilt angle of scanning mirror ispresented, and dynamic measurement system for tilt angle of scanningmirror is developed, which can accomplish the static and dynamic lasernon-contact measurement for scanning mirror of which the parameters areswing frequency, zero position angle, amplitude value, maximum andminimum tilt angle, difference of peak values, average of peak values, etc.Swing curve can be graphically displayed and printing outputted, andaccording to this, swing frequency can be determined. In this paper thecomposition and overall structure of measurement system for tilt angle,device for given attitude, driven power supply of motor, etc are introduced. The analyzes and discussion about dynamic measurement theory for tiltangle of scanning mirror, the method of design for large field view, largerelative aperture special linear scanning optical system are emphasized. Thewindow layout and size limitation of the infrared earth sensor are overcame,which make the measurement results can't be effect by the position ofincident light. The key technology problem of real-time dynamicnon-contact measurement for tilt angle of scanning mirror is settled. Deviceof given attitude is developed by adopting the designed project of two axesrotating floor, six given attitudes of infrared earth sensor can beaccomplished; The frequency of designed driven power supply of motor canbe tuned by adopting the technology of high frequency splitting and thetechnology of narrow-band filter, which settled the problem of drivingmoment motor without brushes bringing along the set of axes swingingfollowing the rule of sine, met the operating requirements for differentfrequency and different load. In addition, in this paper, several key problemsthat they are measurement accuracy and dynamical range, etc are discussedas the linear CCD is used to the technology of measuring angle, and theformula of measurement accuracy and the formula of dynamical range arededuced. The problems of correction of the error for measured data andgraph manipulation are settled by establishing the mathematic model ofsystem and the technology of correction and compensation for measureddata through software of computer. The accuracy of measurement system isvalidated by experiment, results indicate that measurement range of systemis 0～±12°, distinguish ability of system is 0.01°, accuracy of dynamic andstatic measurement for system is super to±0.04°.
|
PDF Full Text Request