Study Of Quick And High Accuracy Pointing Technology Drived By Step-motor Based On Staring Imaging Mode

The Infrared Focal Plane Arrays has entered the stage of practical application. In order to expand the detection field under the premise of maintaining high resolution, scan mirror should point the detection area with high precision quickly coordinated with detector. Operating performance of scan mirror directly affects the image quality of remote sensing camera. The performance of driving motor and rotation angle sensor such as positioning precision, control stability, angle measurement accuracy and stability determines the positioning accuracy and stability of the imaging detector pointing mechanism.The developped driving control mode use synchronous motors and absolute inductosyn constitute tricyclic feedback system to ensure linearity and control precision. As the drive actuator, the stepping motor has been successful applicated in stepscanning mode of Line Array Detector, its operating mode of step progressive impulse control has significance in staring pointing, in particular step staring mode. In this paper under the high requirements for response speed, position control accuracy and angular measuring accuracy and low requirements for linearity characteristics this paper, the use of open-loop step-motor control with absolute pointing Inductosyn realize drive control program and design stepping point test system, which effectively drives the moment of inertia of the load for fast, stable point within the range of 20 °.The advantages of high stability and high reliability of absolute inductosyn in vacuum environment, make it been widely used in the field of aerospace. This paper propose a non-ideal characteristics of the input error model based on RDC, and research the error detection and compensation, basis of analyzing its application of limiting rotation axis angle measurement. Specific studies are as follows: 1.Design the step pointing test system. System achieve less than 3s and not less than 20 ° fast and stable pointing, its control accuracy is better than 0.2″, settling time is less than 0.3s, has 0.2 " stability within long integration time. 2.Improve and design the Absolute Inductosyn information processing system based on tracking Resolver-to Angle, and analysis operational characteristics of the system, achieve angle measurement of stability in 0.5″(3s) and accuracy in 2.5″(3s) 3. Based on the theoretical analysis error of inductosyn angle measuring system, propose the main sources of error of limiting rotation axis angle measurement is nonideal characteristics of the input error of RDC, establish the error model and analysis the error component.4. Build an error detection platform of angle measuring system.Analysis measurement error characteristics and research hardware and software compensation method, after compensating error magnitude less than 2.5″(3 s).