Method for controlling mixing ratio by thermal action in the propellant tanks of space systems
AssigneeComando De OperaçõEs Aeroespaciais - Comae
InventorHenrique Oliveira Da Mata
Life of this patent
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Abstract
A method, which uses real pressure, temperature and mass data obtained from real telemetry, to control the mixture ratio based on the change of the temperature set in its tanks, where the mixture ratio is defined by the ratio between the oxidant mass consumption by the fuel mass consumption. To achieve this, the space system in question must have a bipropellant propulsion system operating in blow-down mode containing independent temperature control systems for each tank. The method is related to the aerospace field, the application of this method is of interest to the areas of manufacturing and operation of space systems.
Claims19
A method for controlling a mixture ratio of propellant consumption for a space system, the space system comprising a bipropellant propulsion system operating in blow-down mode and having a respective sensor array communicating with a respective one of the propellant tanks, the propellant tanks each having an independent thermal control system and a respective supply line to connect each of the propellant tanks to an engine, comprising the steps of:
- a) reading temperature and propellant mass in each of the propellant tanks, and pressure in the respective supply line, by the respective sensor array;
- and
- b) operating each independent thermal control system by:
- i) carrying out Data Acquisition (211) by a telemetry system that receives real time data of the temperature in each of the propellant tanks, the propellant mass in each of the propellant tanks, and the pressure in each of the supply lines read by the sensor arrays, and defining a Metric Definition (212), a Parameter Estimation (213), and a Relation Evaluation (214) by a computational tool communicating with the telemetry system, wherein the computational tool generates a relation P(T) of the pressure as a function of the temperature in the propellant tanks;
- ii) carrying out Data Acquisition (221) by the telemetry system that receives real time data the of propellant mass in each of the propellant tanks and of the pressure in the propellant tanks from the sensor array, and defining a Metric Definition (222), a Parameter Estimation (223), and a Relation Evaluation (224) by the computational tool, wherein the computational tool generates a relation MR(P) of mixture ratio as a function of the pressure in the propellant tanks;
- and
- iii) Receiving Input Data (231) by the computational tool that receives a Mixture Ratio of Interest (MRI), and generating a Pressure Estimation (232), a Mixture Ratio Estimation (233), and an Error Minimization (234) by the computational tool using both of the relations P(T) and MR(P) from steps i) and ii), in a recursive manner, resulting in a direct relation MR(T) of mixture ratio as a function of temperature, wherein the computational tool inverts the relation MR(T) by applying a search algorithm to generate an inverse relation T(MR) of temperature as a function of mixture ratio, whereby the computational tool applies the Mixture Ratio of Interest (MRI) to the relation T(MR), generating a propellant tank temperature (TA) to be set in the propellant tanks, and outputting (235) the propellant tank temperature (TA) in a display embedded in the space system,
- wherein the independent thermal control systems act thermally on the propellant tanks, adjusting the temperature (T) to the propellant tank temperature (TA) in the propellant tanks, allowing the bipropellant propulsion system to operate at the Mixture Ratio of Interest (MRI), thereby causing a difference between an Adjusted Mixture Ratio (MRA) and the Mixture Ratio of Interest (MRI) to approach zero.
Dependencies are inferred from the claim text.