激光导引头角跟踪误差对激光精确制导的影响

Effects of Angular Tracking Error of Laser Seeker on Precise Laser Guidance

为了使激光导引头能以较高的概率探测到制导激光且以较高的跟踪精度跟踪目标,评估了在制导过程中激光导引头对目标的视线角跟踪精度。在四象限探测器接收的光斑信号服从高斯分布的条件下,建立了光斑中心与偏差分量的关系,通过仿真验证了其正确性。将该关系作为试验标定拟合的关系,建立了光束偏转角关系。由于噪声干扰电流具有随机性,对光束偏转角在(0,0)处进行了二元泰勒展开,并得出了角跟踪误差的近似表达式,以角跟踪误差标准差作为激光导引头视线角跟踪精度的评价标准,结合制导激光在大气传输中的能量衰减,得出了角跟踪误差标准差与目标指示器参数、激光导引头参数以及作用距离的关系,研究了不同参数对角跟踪误差标准差的影响。结果表明:当信噪比一定时,角跟踪误差标准差随着光斑半径减小而减小,可通过调节光敏面的安装位置减小光斑半径,从而提高激光导引头的角跟踪精度;当光斑半径为1 mm、噪声干扰电流标准差为0.2μA时,若目标指示器单脉冲能量为150 mJ,则激光导引头对8 km处目标的角跟踪误差标准差为0.9737×10^-3 rad;角跟踪误差标准差随着单脉冲能量的增大而减小,可通过提高目标指示器单脉冲能量从而提高激光导引头在特定作用距离处对目标的角跟踪精度。

To enable the laser seeker to detect the guidance laser with a higher probability and track the target with higher tracking accuracy,the tracking accuracy of the sight angle of the laser seeker to the target during the guidance process is evaluated.The relationship between the spot center and the deviation component is established under the condition that the spot signal received by four quadrant detector obeys the Gaussian distribution,and its correctness is verified by simulation.This relationship is taken as a test calibration fit,and a beam deflection angle model is constructed.Due to the randomness of the noise interference current,a binary Taylor expansion of the beam deflection angle at(0,0)is carried out and an approximate expression of the angular tracking error is obtained.The standard deviation of the angular tracking error is used as the evaluation standard of the sight angle tracking accuracy of the laser seeker.The relationship among the standard deviation of the angular tracking error,the parameters of the target indicator,the parameters of the laser seeker,and the working distance is established by combining the energy attenuation model of the guidance laser in the atmospheric transmission.The influences of different parameters on the standard deviation of angular tracking error are discussed.This approach shows that:when the signal-to-noise ratio is constant,the standard deviation of the angular tracking error decreases as the spot radius decreases;the spot radius can be reduced by adjusting the mounting position of the photosensitive surface,thereby improving the angular tracking accuracy of the laser seeker is improved;when the spot radius is 1 mm and the standard deviation of the noise interference current is 0.2μA,if the single pulse energy of the target indicator is 150 mJ,the standard deviation of the angular tracking error of the laser seeker to the target at a distance of 8 km is 0.9737×10^-3 rad.The angular tracking accuracy of the laser seeker for the target at a specific working distance can be improved by increasing the single pulse energy of the target indicator.