1、 System composition
The basic composition of the photoelectric pod is divided into a suspended spherical turret and a display control processing system. From a hardware perspective, the turret includes a U-shaped bracket, a spherical platform, an angle measurement system, an electric control drive system, a gyroscope, a gyroscope stabilization circuit, a photodetector, a TV and infrared tracker, and interface circuits. In principle, the turret can be divided into two parts: a stable platform and a photoelectric payload (detector). The photoelectric load is installed on a stable platform, which isolates the vibration of the carrier through a gyroscope stable platform, obtaining a relatively stable platform space in the inertial space. Under the drive of control instructions, the photoelectric load can search, capture, track, and locate the target. Therefore, the airborne gyroscope stabilization platform achieves two major functions: spatial stability and the ability to track targets. Detectors (payloads) can be combined in different combinations according to the different tasks they undertake. For airborne pods that complete search and tracking tasks, they generally include visible/low light cameras, infrared thermal imagers, and laser rangefinders. In addition, as needed, the payload can also be equipped with laser illuminators, laser indicators, laser alarms, and image spectrometers.
2、 Working principle
The working principle of the photoelectric pod is to use visible light (TV) and infrared imaging sensors as position error sensors in the closed-loop control system, output target orientation information or external guidance information, and search for the target area with rotation instructions provided by the main control computer or manual. After the turret forms a closed-loop tracking with the onboard tracking detector, the processed target azimuth and elevation deviation output is transformed into a proportional control signal, which acts on the torque sensor of the gyroscope. The control torque output of the torque motor is proportional to the azimuth and pitch errors, so that the photoelectric detector of the tracking frame maintains tracking of the target. In addition, by adding corresponding sensors and using certain algorithms, the pod can also achieve relative positioning of the target. There are two types of positioning methods: active positioning and passive positioning. Active positioning is the process of using a laser rangefinder to obtain accurate relative position and velocity of a target by measuring its distance from the aircraft; Passive positioning is the use of television/infrared imaging measurement sensor platforms to measure the angle changes of targets and obtain rough target distances.