ROSpace: a mission simulator for CleanSpace One and beyond - - PowerPoint PPT Presentation

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ROSpace: a mission simulator for CleanSpace One and beyond - - PowerPoint PPT Presentation

Feb 15, 2024 313 likes •822 views

ROSpace: a mission simulator for CleanSpace One and beyond Christophe Paccolat Christian Lanegger Michael Pantic Overview CleanSpace One Rospace Requirements & Framework Evaluation of Simulation Toolkits Layout of

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ROSpace: a mission simulator for CleanSpace One and beyond

Christophe Paccolat Christian Lanegger Michael Pantic

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Overview

  • CleanSpace One
  • Rospace – Requirements & Framework
  • Evaluation of Simulation Toolkits
  • Layout of the Physics Engine
  • Validation of Orbit and Attitude Propagation

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Our Mission

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Clean Space One

  • Capture and de-orbit SwissCube

increase awareness and responsibility in regard to orbit removal demonstrate technologies needed for ADR

  • Challenges:

high tumbling rate uncooperative rendezvous

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ROSpace Simulator

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ROSpace – Requirements

  • Requirement 1: Publishable & Reproducible
  • Requirement 2: Verification
  • Requirement 3: Model Accuracy
  • Requirement 4: Customizable

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ROSpace – Simulation Framework

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Evaluation of Simulation Toolkits

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Toolkit – Evaluation Criteria

  • Criterion 1: Completeness
  • Criterion 2: Flexibility
  • Criterion 3: User-Friendliness

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Options for Capture Simulator

  • Software with GUI: STK (commercial), GMAT (open-source)

strength in high-level mission simulation (orbital maneuvers, coverage planning)

  • Software libraries: 42 (C++), Basilisk (C++), TUDAT (C++), OREKIT (Java)

which one to chose?

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Options for Capture Simulator

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42 Basilisk TUDAT OREKIT

+

  • C++
  • Multi-body dynamics
  • Contact forces
  • Attitude dynamics
  • C++
  • Actuator & sensor

models

  • Attitude dynamics
  • C++
  • User-Friendly (tutorials)
  • Validated & successfully

tested

  • Well documented
  • Variety of sophisticated

models

  • Deprecated

atmosphere model

  • Only low coefficient

gravity models

  • No tide models
  • Documentation
  • Only general purpose

models listed

  • Simple radiation pressure

model

  • Not tested in real world
  • No attitude dynamics
  • Java
  • No attitude dynamics
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Layout of the Physics Engine

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General Layout

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  • Engine embedded in ROS

environment

  • :Rospy provides

communication tools between ROS-nodes

  • Clock interface separated

from PropagationNode

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Clock Library

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Clock Library

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  • Handles time based on

commands from first caller class

  • Multiple calls from different

nodes result into error

  • Time can be manipulated with

developed GUI

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Clock Library

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Propagation Node

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Propagator Node

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Propagator Builder

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Propagator Builder

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Propagator Builder

  • Builder pattern
  • .yaml file to define

propagator’s setup

  • Expandable by adding

classes inheriting from corresponding factories

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  • Builder pattern
  • .yaml file to define

propagator’s setup

  • Expandable by adding

classes inheriting from corresponding factories

Propagator Builder

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Numerical Propagation

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Numerical Propagation

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Numerical Propagation

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Numerical Propagation

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Validation of Orbit Propagation

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EnviSat Model

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  • Simulation results compared against

precise orbit data sets of EnviSat for February 2012

  • Mass: 7834 kg
  • Perfectly nadir pointing attitude assumed
  • Solar Panel oriented in direction of best

lighting conditions

  • Shadowing effect neglected
  • Assumptions made for surface material
  • Body size

Sensitivity Analysis

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Sensitivity Analysis

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  • 12 different sizes for masses between 7800 – 8000 kg with 10kg increment
  • Solar panel areas: 40 m2 (left) and 60 m2 (right)
  • Period: 04.02.2012 at 21:55:26 – 06.02.2012 at 00:23:25
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Short-Term Propagation

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Long-Term Propagation

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Long-Term Propagation

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Validation of Attitude Propagation

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Attitude Propagation

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  • CSSWE – Passive Magnetic Attitude Control
  • 3U CubeSat with mass of 3 kg
  • Initial angular velocity: (𝜕𝑦, 𝜕𝑧, 𝜕𝑨) = 10, 5, 5

° 𝑡

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Attitude Propagation

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  • CSSWE – Passive Magnetic Attitude Control
  • 3U CubeSat with mass of 3 kg
  • Initial angular velocity: (𝜕𝑦, 𝜕𝑧, 𝜕𝑨) = 10, 5, 5

° 𝑡

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Additional Slides

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Active Debris Removal

  • More than 23‘000 debris larger than 5 cm orbiting Earth
  • Even without adding objects to space environment number of debris would grow

due to collisions Kessler Syndrome

  • Adopted “Post Mission Disposal” (PMD) guidelines do not prevent completely

debris increase Active debris removal required

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ROSpace – Simulation Framework

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  • Augments on-board and on-ground sensor readings
  • Implemented: Black box model

returns bearing angles based on relative position and adds artificial noise

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ROSpace – Simulation Framework

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  • Represents all on-board software
  • Implemented: Relative navigation filter

estimates the relative state of chaser based on inputs from relative navigation sensors and on-board state estimation

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ROSpace – Simulation Framework

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  • Models resulting thrust forces based on flight software

commands

  • Implements: magneto-torque & simple dipole model
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ROSpace – Simulation Framework

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  • Models forces and torques acting on the spacecraft and

integrates its state (position, velocity, attitude, …) Physics engine

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Simulation Time

  • Propagator node updates simulation time
  • Simulation time represented as integer in [ns]

no floating point error python integer ’long’ integer object

  • 𝑈𝑇𝑢𝑓𝑞𝑇𝑗𝑨𝑓 ∗ 𝑄𝑣𝑐𝑚𝑗𝑡ℎ𝐺𝑠𝑓𝑟 = 𝑆𝑓𝑏𝑚𝑈𝐺𝑏𝑑𝑢𝑝𝑠
  • Start/Pause: starts/stops only simulation time

update not ROS nodes

  • Simulation warns if real-time factor cannot be

achieved

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Box-Wing Model

  • Satellite modeled as box with

wings as solar panels

  • Discretized into 𝑜 volumes

with mass 𝜀𝑛

  • Surface discretized into 𝑛

surfaces with area 𝜀𝐵

  • Solar Panels 2D planes with

fixed direction

  • No shadowing effect

implemented

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𝜀𝐵𝑡𝑏𝑢 𝜀𝑛

Ԧ 𝑠𝜀𝑛𝑗 Ԧ 𝑠

𝑇𝑄𝑗

Ԧ 𝑠𝜀𝐵𝑗

𝜀𝐵𝑇𝑄𝑗

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Attitude Propagation

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  • Gravity Gradient Stabilization inspired by

NASA‘s Transit Satellites

  • 6 booms with point masses of 1.4 kg at end
  • Inertia tensor is diagonal matrix with

𝐽𝑦 = 𝐽𝑧 ≫ 𝐽𝑨

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Attitude Propagation

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EnviSat – Absolute Error for 40m2

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EnviSat – Absolute Error for 60m2

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Dipole Model

  • One hysteresis loop assumed for

every field strength cycle

  • Real hysteresis rod follows different

loop

  • 𝐼𝑑

Coercive Force 𝐶𝑠 Remanence 𝐶𝑡 Saturation Induction

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Provided File Data

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