AERO 421: Spacecraft Attitude, Dynamics, and Control Final Project.

Overview

AERO - 421 Final Project Redevelopment

Spacecraft Attitude, Dynamics, and Control: Simulation to determine and control a satellite's attitude in LEO.

Background

AERO-421, or Spacecraft Attitude, Dynamics, and Controls, is a class taught at the California Polytechnic State University at San Luis Obispo (Cal Poly SLO) which serves as an...

"Introduction to spacecraft attitude dynamics and control... [and] fundamentals of guidance and navigation systems... [with emphasis in] analysis and design of control systems for aerospace vehicles." - Cal Poly Aerospace Engineering Course Catalog

The final project in the course was to develop a simulation to determine a satellite's attitude in Low Earth Orbit (LEO), consider and model detumbling from a launch vehicle, consider and model disturbances due to external forces i.e., Solar Radiation Pressure (SRP), and to consider and model control via onboard reaction wheels.

More information regarding the 6 different parts can be found below.

The initial project was developed in MATLAB, however, the project will be completely redeveloped in Python to showcase controls and software development skillsets.

Part 0: Context and Given Data

The project will explore modeling and simulation of the various stages of a spacecraft mission, specifically simulating the attitude dynamics from initial spacecraft deployment to operation. In this simulation, the spacecraft is an Earth observing satellite and an attitude determination and control system must be designed using reaction wheels to ensure the spacecraft maintains pointing nadir.

Orbital Data:

  • h (angular momentum) = 53335.2 km^2/s
  • e (eccentricity) = 0
  • Ω (Right Ascension of Ascending Node) = 0 deg
  • i (inclination) = 98.43 deg
  • ω (Argument of Perigee) = 0 deg
  • θ (True Anomaly) = 0 deg
  • ϵ-LVLH (Initial Quaternion relating the body to the LVLH frame) = [0, 0, 0]; η = 1

Detumble Phase:

  • Spacecraft is a square box with 2 meters on each edge with total mass of 640 kg
  • Initial Angular Velocity of [-0.05, 0.03, 0.2] rad/s relating the body to the ECI frame

Normal Operations:

  • Spacecraft bus is a 2 meter cube with mass of 500 kg. The center of mass of the spacecraft is located at the geometric center of the bus.
  • A rectangular sensor is attached to the face pointing towards the Earth (+Z-axis) and is 1 meter long and 0.25 meters square. The sensor has a mass of 100 kg.
  • Two solar panels are deployed along the +/- Y-axis and are constrained to rotate about the +/- Y-axis. The solar panels are 3 meters long (in the Y-axis), 2 meters wide, and 0.05 meters thick. Each panel has a mass of 20 kg and the center of mass is located at the geometric center of the panel. The solar panels do not rotate relative to the spacecraft bus.
  • Assume all spacecraft components have uniform density with centers of mass located at the geometric centers of each component
  • Magnetically, the spacecraft residual magnetic dipole moment can be modeled as pointing in the -Z direction with magnitude 0.5 A-m^2
  • See the figure below for the spacecraft schematic
  • Because the thrusters are not actually fully-modulated thrusters, the spacecraft will have a residual angular velocity of [0.001, -0.001, 0.002] rad/s relating the body to the ECI frame after the detumble phase.
  • During operation the spacecraft is required to point at the target on the ground to within 0.001 degrees 3-sigma using the reaction wheels used in the reaction wheels part.

Spacecraft Schematic

Part 1: Mass Properties

Determine the mass and inertial properties of the spacecraft for both the detumble and the normal operations phases.

Outputs:

  • Total mass of the spacecraft
  • Center of mass relative to the spacecraft bus center of mass. The body frame will be located at the center of mass of the whole spacecraft
  • Intertia matrix of the whole spacecraft about the center of mass of the spacecraft

Part 2: Torque Free Motion

Model the torque free orbital and attitude motion of the spacecraft

Outputs: Plots for...

  • Euler angles and quaternions relating body to ECI reference frames
  • Angular velocity of the spacecraft in body components for one orbit of the normal operations phase

Part 3: Detumble

Simulate the motion of the satellite during the detumble phase. Assume fully modulated thrusters and use direct velocity feedback

Outputs: Plots for...

  • Euler angles and quaternions relating body to ECI reference frames
  • Angular velocity of the spacecraft in body components for the detumble phase
  • Torque components in the body frame

Part 4: Disturbance Simulation

Add the four disturbance models to the simulation:

  • Atmospheric Drag
  • Solar Pressure
  • Gravity Gradient
  • Earth Magnetic Field

Use the following model for the atmospheric density. Notice that h is the height above the Earth's surface in kilometers where R_Earth equals 6378km

Disturbance Model

Consider the simulation epoch to be March 20, 2021. Disregard any variations of the ECI representation of the sunlight direction during the simulation.

Outputs: Plots for...

  • Euler angles and quaternions relating the body to the ECI reference frame
  • Euler angles and quaternions relating the body to the LVLH reference frame
  • Angular velocity of the spacecraft relative to the ECI frame expressed in body components
  • Angular velocity of the spacecraft relative to the LVLH frame expressed in body components
  • Torque components for atmospheric drag, solar radiation pressure, gravity gradient, and earth magnetic field

Part 5: Reaction Wheel Control

Determine the control gains for a full state feedback 3-axis reaction wheel control system. Use the requirements of ζ = 0.65 and t_s = 30 sec

The positions of the 3 reaction wheels are [1, 0, 0], [0, 1, 0], and [0, 0, 1]. Each reaction wheel can be modeled as a simple cylinder with radius of 0.3 m and a height of 0.02 m

Outputs: Plots for...

  • Euler angles and quaternions relating the body to ECI reference frame
  • Euler angles and quaternions relating the body to LVLH reference frame
  • Angular velocity of the spacecraft relative to the ECI reference frame expressed in body components
  • Angular velocity of the spacecraft relative to LVLH frame expressed in body components
  • Commanded moment from the determined control law
  • Wheel speed of each reaction wheel

Part 6: Visualization

Determine and animate the quanterions of the spacecraft, from ECI to body frame, for the duration of 1-5 revolutions.

Output:

  • Table of quaternion and time data
  • Video or other animation file to show the revolution of the spacecraft
Owner
Gagandeep Thapar
- (he/they) - 4th year Aerospace Engineering (w/ CS Minor) at Cal Poly SLO - Interested in Launch Vehicle and Spacecraft Controls and Avionics
Gagandeep Thapar
Micropython automatic watering

micropython-automatic-watering micropython automatic watering his code was developed to be used with nodemcu esp8266, but can be modified to work with

1 Nov 24, 2021
Volkswagen ID component for Home Assistant

Volkswagen ID component for Home Assistant This folder contains both a generic Python 3 library for the Volkswagen ID API and a component for Home Ass

55 Jan 07, 2023
A ch341dll Wrap is for using in Python 32bits windows to access I2C SPI and MDIO (by GPIO), and Demo with display PC sreen on OLED by i2c or SPI .

ch341dll_wrap_typcal_app A ch341dll Wrap is for using in Python 32bits windows to access I2C SPI and MDIO (by GPIO). In addition, I provided 3 Demo. I

13 Jan 02, 2023
Technical Answers to Real-World Problems. Evolution of Watering Manually to Watering Automatically.

Automatic Watering System using Soil Moisture Sensor and RTC Timer with Arduino Technical Answers to Real-World Problems Know the plant, Grow the plan

NelakurthiSudheer 3 Jan 03, 2022
PyLog - Simple keylogger that uses pynput to listen to keyboard input.

Simple keylogger that uses pynput to listen to keyboard input. Outputs to a text file and the terminal. Press the escape key to stop.

1 Dec 29, 2021
A install script for installing qtile and my configs on Raspberry Pi OS

QPI OS - Qtile + Raspberry PI OS Qtile + Raspberry Pi OS :) Installation Run this command in the terminal

RPICoder 3 Dec 19, 2021
circuitpython version of PyBasic for microcontrollers

cPyBasic Circuitpython version of PyBasic for microcontrollers Current version work only for Adafruit titano & CardKB for now. The origninal PyBasic w

BeBoXoS 3 Nov 14, 2021
A IC scan test interface for Arduino

ICSCAN_ARDUINO Prerequisites Python 3.6 or higher arduino uno or nano what is this It is a bitstream tranceiver to test IC chip It sends bitstream to

Nifty Chips Laboratory 0 Sep 15, 2022
Estimation of whether or not the persons given information will have diabetes.

Diabetes Business Problem : It is desired to develop a machine learning model that can predict whether people have diabetes when their characteristics

Barış TOKATLIOĞLU 0 Jan 20, 2022
HA-Edge-Connector - HA Edge Connector For Python

HA-Edge-Connector 1. Required a. Smartthings Hub & Homeassistant must be in same

chals 21 Dec 29, 2022
ModbusTCP2MQTT - Sungrow & SMA Solar Inverter addon for Home Assistant

ModbusTCP2MQTT Sungrow & SMA Solar Inverter addon for Home Assistant This addon will connect directly to your Inverter using Modbus TCP. Support model

Teny Smart 40 Dec 21, 2022
Rasberry Pie GPIO memory game. Press the corresponding key to the lit LED.

RPie-keyboard-game Rasberry Pie GPIO memory game. Press the corresponding key to the lit LED. Randem LED (general output) is lit up on rasberrypi rand

Shawn Dowling 1 Oct 24, 2021
DongshanPI Seven for STM32MP157DAC.

STM32MP1 Buildroot External Tree

DongshanPI 14 May 06, 2022
Aqara Camera G3 integration for Home Assistant

Aqara Camera G3 integration for Home Assistant ATTENTION: The component only works after enabled telnet. Only supportd stream. Not support still image

14 Dec 18, 2022
A Simple Python KeyLogger App

✨ Kurulum Uygulamayı bilgisayarınızda kullana bilmek için bazı işlemler yapmanız gerekiyor. Aşağıdaki yönlendirmeleri takip ederek bunu yapabilirsiniz

VorteX 7 Jun 11, 2022
Segger Embedded Studio project for building & debugging Flipper Zero firmware.

Segger Embedded Studio project for Flipper Zero firmware Установка Добавить данный репозиторий в качестве сабмодуля в корень локальной копии репозитор

25 Dec 28, 2022
Pylorawan is a Micropython wrapper for lorawan devices from RAK Wireless.

pylorawan Pylorawan is a Micropython wrapper for lorawan devices from RAK Wireless. Tested on a Raspberry PI Pico with a RAK4200(H) Evaluation Board (

Peter Houghton 3 Nov 04, 2022
Implementation of Forwards Kinematics, Inverse Kinematics, Point to Point Movement and Synchronous movement for Kuka KR 120 R2700-2.

I made this project for my university course in robotics. I rarely found any information regarding the implementation of mathematics in code. So I decided to make this repo in order to help others :)

2 Dec 27, 2022
Poupool is an overflow swimming pool control software

Poupool - The swimming pool controller Poupool is a swimming pool control software. It is based on Transitions, Pykka and Paho MQTT. The user interfac

Cyril Jaquier 8 Jul 18, 2022
Turn your Raspberry Pi Pico into a USB Rubber Ducky

pico-ducky Turn your Raspberry Pi Pico into a USB Rubber Ducky Install Requirements CircuitPython for the Raspberry Pi Pico adafruit-circuitpython-bun

Konstantinos 5 Nov 08, 2022