Fast position control of the lensbarrels of aerial cameras without overshoots in omnirange
黄浦 Huang Pu, 修吉宏 XIU Ji-hong, 李军 Li Jun, 李友一 LI You-yi, 杨秀丽 YANG Xiu-li · Optics and Precision Engineering · 2013
To eliminate the overshoot of lensbarrel of an aerial camera in process of position control,a tracking differentiator was used to process step signals and to design a position transient process to control accurately the lensbarrel position without overshoots.First,the theory of the tracking differentiator was described and its characteristics were expatiated.And then,by taking position step response with a 90° input as an example,the transient process was designed and compared with that of no transient process design.Experiment results show that the position overshoot of lensbarrel can be eliminated completely through the appropriate transient process design,and the regulation time is reduced also.In the case of 90° step input,the system overshoot is reduced from 24.4% to zero and the regulation time is shorten by 28.8%.Furthermore,the fast position control of the lensbarrel was realized with non-overshoot in omnirange,in which the least square method was used to fit a curve of step input and a speedability parameter in transient process.The optimum parameter of the transient process was calculated according to the step input in control process.This method has been used in the lensbarrels of aerial cameras,and it obtains a good effect and provides significant and practical values for improving the dynamic performance of systems.