Longitudinal guidance and control of reentry vehicle in the approach and landing phase

Approach and Landing phase is an important and critical part of Reusable Launch Vehicle (RLV) mission. The challenging task is to deliver a RLV to its landing site safely and reliably. Hence a control scheme has to be designed that accomplishes this task. In this paper a well tuned PID controller was first designed. Using the inputs and outputs of the PID controller a Fuzzy logic controller was designed. The controller tracks the guidance commands and limits the angle of attack in order to steer the vehicle along the desired trajectory. Simulations were performed in MATLAB for the RLV using the above two controllers. The simulation results demonstrates that the latter controller offers better performance.