Closed Loop Guidance Algorithm for Solid Propellant Rocket*

During the flight, a satellite launch vehicle is subjected to disturbances. If the vehicle continues to suffer these disturbances and no compensation is applied, the mission of the vehicle can be jeopardized. This article presents a closed loop guidance algorithm for solid propellant rocket with the purpose to make decisions about how to drive the vehicle in order to insert the payload into a specific circular orbit with previously specified parameters, taking into account disturbances during the flight, such that the dispersion around the final orbit is minimized. This strategy calculates onboard the pitch angle profile to the attitude control system, based on current conditions of flight and on the final objective to be reached, by ensuring that this autonomous method will reduce the effects of the disturbances that occurs during the flight, and consequently the dispersion on the final orbit parameters. In order to evaluate the performance of the guidance algorithm, the Monte Carlo simulation was performed. The results obtained show that the guidance strategy is an important tool that helps to obtain a successful mission when disturbances occur during the flight, minimizing the effects of these disturbances on the overall launcher's mission.