Guidance algorithms for rocket launchers ensure the target is reached but do not take into account the left over propellant. Left-over propellant causes target over-shoots or numerous constraints on passivation and re-entry of stages. Our client had identified a guidance technique enabling complete propellant consumption when target is reached and asked us to enhance, implement and test this method.

Methode_innovante_de_guidage_fus%c3%a9e

Client problem

Rocket launchers are governed by three entities:

  • Navigation defined the target and the present position of the rocket and communicates it to guidance.
  • Guidance calculates the instructions to direct the rocket from the current position to the target.
  • Pilot executes the guidance instructions .

Guidance algorithms transmit two types of instructions:

  • Thrust orientation (thanks to tail pipe pivoting),
  • Engine stop.

For numerous engines, it is impossible to stop the combustion (mainly solid rocket boosters). If the engine still has some thrust capacity when the target is reached, it will over shoot the target.

Even if the engine can be stopped, there can be propellant still present in the launcher stage when the target is reached. This causes a large number of constraints and problems in terms of stage passivation and stage re-entry.

A guidance method that would have the capacity to ensure the complete consumption of propellant at the moment when the launcher reaches its target would alleviate the 2 problems presented.

Our client had identified a possible solution to his guidance problem in academic literature. He asked us to test the feasibility of the described guidance technique.

Solution proposed

Cornis conducted an extensive exploration, using scientific publications and patents to collect a maximum amount of information on the targeted technique. This allowed Cornis to identify other publications that were key to implementing and making the guidance method selected by our client work .

The second step of the study was implementing the guidance algorithms based on the literature review. It was necessary to complete and add some steps in the guidance algorithm that were not presented in the literature. With our client we were thus able to elaborate a complete operational guidance method.

A flight simulator was then designed and implemented to test the performances of the guidance algorithms (robustness, stability, etc.). These test allowed us to enhance the guidance algorithm.

Other missions

  • Industrialisation

In order to better understand the dynamic behaviour of rocket launchers during flight, it is critical to analyse the vibration data recorded during flight. The classical experimental modal analysis techniques are not applicable since it is impossible to control or measure the dynamic loads applied to the launcher.

In order to better understand the dynamic behaviour of rocket launchers during flight, it is critical to analyse the vibration data recorded during flight. The classical experimental modal analysis techniques are not applicable since it is impossible to control or measure the dynamic loads applied to the launcher.