Control System Design Of The Stable Platform For Shipborne Optical Observation Instrument Based On DSP

Ship will swing when sailing in the storm, this disturbance may cause the boresight of the ship’s Observation Instrument waggle. This may lead to the image drift or even lost the target. With the development of the inertial technology, the precision machinery, and the electronic technique, the stable platform emerged. When install the Observation Instrument on the stable platform,it can stable the Observation Instrument’s boresight in the Inertial Coordinate System, to overcome the disturbance which the swing of the ship brings to the Observation Instrument. Achieve the purpose of stabilizing the observe image.High precision inertial component is expensive, it is used in the optical axis stabilized platform will increase the cost of the system. Usually ships will be equipped with inertial navigation system, so paper use the attitude angle output of the INS (Inertial Navigation System) as the inertial devices’ measurement and use the biaxial stable platform to stability the observer’s boresight. For the actual needs of the marine optical observation instrument devised an affordable, high-performance stable platform control systems. The main work of the paper is as follows:1. Using two-axis stabilization platform stable photoelectric viewer visual axis. Put forward the project of stabilized platform based on output stable platform inertial navigation system. By ship and viewer visual axis in geographic coordinates calculated aiming angle of the viewer visual axis in the coordinate system of the deck aiming Angle, through the coordinate transformation matrix, which get from the second kind euler Angle. From what has been discussed above we get the input stabilized platform servo system.2. Design and implement the hardware system for the servo controller of the stable platform. Use the TMS320F28335 as the core of the servo system. Get the attitude angle from the INS and get the viewer visual axis’s aiming angle from master control system in the geographic coordinates, through the communication circuit. Get the feedback angle of the stable platform by the Dual-channel resolver. Design the D/A converter circuit and optocoupler isolation circuit to achieve the output of the controller.3. Establish the mathematical model of the stable platform and design the control method of the platform. Use current loop, velocity loop, position loop and feedforward correction to achieve the control system. Design the series correction link of current loop, speed loop and the position loop. Design the feed-forward correction link of the position loop. At last use Simulink to simulate and analyze the feasibility of the system.4. Design the process of the Control system. Achieve the Dual-channel resolver combination of the coarse channel and the fine channel to get the feedback angle in the DSP.The series correction link of position loop use position type PID algorithm. Use the double linear variation method to discretize the feedforward transfer function which is basd on differential and filter. At last, complete the control of the stable platform in the DSP.Verify performance indicators of the control system through experiments. The experiment explains the feasibility of the system, prove that the control system has higher steady-state and dynamic performance and it has practical engineering application value.