Design Of Target Azimuth Detecting Circuit In Hardware-in-the-Loop Simulation System Of Semiactive Laser Guidance

The hardware-in-the-loop simulation system of semiactive laser guidance plays an important role in the laser guidance weapons developing process, application simulation and training. A target azimuth detecting circuit was designed based on the laser seeker and laser designator in the paper, which is the steady foundation of developing the hardware-in-the-loop simulation system of semiactive laser guidance.The four-quadrant detector is the key device for target azimuth detection in the hardware-in-the-loop simulation system. Beginning with three bearing measurement algorithms of the four-quadrant detector, the paper analyzed add and substract algorithm in detail, discussed angle measurement error of the algorithm in theory, and studied three factors which cause angle measurement error in the algorithm.Received laser powers of the detector and detection distance were decided by optical receiving system. Based on the folded and reflected optical receiving system inside the laser seeker, the paper analyzed signal laser power and background light power, and then calculated them as well. Without regard to circuit noise, the detection distance was discussed.The target azimuth detecting circuit was composed of a preamplifier circuit, a peak holding circuit and a time discrimination circuit, and the peak holding circuit was the most important researching content. The paper analyzed the trans-conductance peak holding circuit in detail. According to the theory, three schemes of the trans-conductance peak holding circuit was designed and simulated.An experiment was carried out with PCB of the designed circuit. The experiment results were consistant with the theoretic analysis. The structure of the circuit is simple and the reliability is good.