Design of an Optimized Controller for Docking System for Space Application

Autonomous docking is a technology used for current space programs, which includes missions such as resupply and repair to the International Space Station (ISS) and space exploration of the Mars, Moon etc. For this docking system, Servo motor design is a main part which includes the modeling of BLDC motor and designing a compensator for meeting the docking requirements. The compensation scheme includes PI controller in the plant to meet the plant requirements. For controlling the engine a Brushless DC torque motor is used. The system along with the compensator forms a closed loop system. It can be concluded from the step response that the compensated system ready for motion control for fine alignment and docking of spacecrafts. An optimization problem is formulated whose objective is to find a parameter value that reduces the error between the plant and model outputs. Design of Controller using PID tuner, Trial and error method and Genetic Algorithm are considered. A comparison study is conducted to analyze the best and optimized method. MATLAB/SIMULINK is used as the simulation tool to evaluate the entire behavior of the system.