ADCS - Spacecraft Attitude Determination and Control

Cover
Contents
List of examples
List of figures
Biography
Michael Paluszek (1954–)
Preface
Acknowledgments
1 Introduction
1.1 Overview of the book
1.2 Types of spacecraft
1.3 Courses based on this book
1.3.1 A one-semester course
1.3.2 A half-semester course
1.3.3 An eight-lecture course
References
2 History
2.1 Space story
2.2 Introduction
2.3 Pre-1950 – dreaming of space
2.4 1950s – getting started
2.5 1960s – the Golden Age: Apollo to the moon
2.6 1970s – the Space Shuttle era
2.7 1980s – internationalization
2.8 1990s – Hubble
2.9 2000s – commercial space is reborn
2.10 2010s – the space station and beyond
2.11 The future
References
3 Single-axis control
3.1 Space story
3.2 Introduction
3.3 Dynamical systems
3.4 Control system
3.5 Kalman filter
3.6 Simulation
3.7 Adding a mode
4 ACS system design
4.1 Introduction
4.2 Design flow
4.3 Organization of ACS design teams
4.4 Requirements analysis
4.4.1 Direct requirements
4.4.2 Indirect (or derived) requirements
4.4.3 Control-system requirements
4.5 Satellite design
4.5.1 Selecting a satellite configuration
4.5.2 Selecting a control strategy
4.5.3 Selecting actuators
4.5.4 Thrusters
4.5.5 Wheels
4.5.6 Pivoted wheels and control-moment gyros
4.5.7 Selecting sensors
4.5.8 Selecting processors
4.5.9 Selecting delta-V engines
4.5.10 Selecting the station-keeping engines
4.5.11 Selecting the interfaces
4.5.12 Cost
5 Kinematics
5.1 Space story
5.2 Introduction
5.3 Euler angles
5.4 Transformation matrices
5.5 Quaternions
5.5.1 Introduction
5.5.2 Fundamental properties of the quaternion
5.5.3 Quaternion nomenclature
5.5.4 Quaternion operations
5.5.5 Quaternion transformations
5.5.6 Quaternion derivative
5.5.7 Small angles
5.5.8 Physical interpretation of the quaternion
5.5.8.1 Single-axis rotation
5.5.8.2 Multiple-axis rotation
5.5.8.3 Small rotation
5.5.9 Incremental quaternion for maneuvers
5.5.10 Angle and unit vector to a quaternion
5.5.11 Axis-alignment quaternion
5.5.12 Small angles
5.5.13 Quaternion interpolation
6 Attitude dynamics
6.1 Space story
6.2 Introduction
6.3 Inertia matrix
6.3.1 Definition
6.3.2 Inertia matrix from components
6.3.3 Common inertia matrices
6.4 Rigid body
6.5 Gyrostat
6.6 Dual spin
6.7 Gravity gradient
6.8 Nutation dynamics
6.9 Planar slosh model
6.10 N-body hub with single degree-of-freedom hinges
6.11 N-body hub with wheels
6.12 Control-moment gyros
6.13 Flexible structures
References
7 Environment
7.1 Space story
7.2 Introduction
7.3 Optical environment
7.3.1 Solar radiation
7.3.2 Earth albedo
7.3.3 Earth radiation
7.4 Atmosphere
7.5 Plasma
7.6 Gravity
7.6.1 Point mass
7.6.2 Spherical harmonics
7.7 Magnetic fields
7.8 Ionizing radiation
References
8 Disturbances
8.1 Space story
8.2 Introduction
8.3 External disturbances
8.3.1 Surface geometry
8.3.2 Aerodynamic
8.3.2.1 Simple drag coefficient
8.3.2.2 Surface-accommodation coefficients
8.3.3 Electrodynamic force
8.3.4 Gravity gradient
8.3.5 Residual dipole
8.3.6 Radio-frequency forces
8.3.7 Solar pressure
8.3.8 Earth-albedo force and torque
8.3.9 Planetary-radiation force and torque
8.3.10 Thermal torque
8.3.11 Thruster plumes
8.3.12 Outgassing force
8.3.13 Shadowing
8.4 Internal disturbances
8.5 Fourier-series representation
References
9 Budgets
9.1 Introduction
9.2 Pointing budgets
9.3 Propellant budgets
9.4 Power budgets
9.5 Mass budgets
10 Actuators
10.1 Space story
10.2 Introduction
10.3 Types of actuators
10.4 Reaction-wheel model
10.4.1 Introduction
10.4.2 Momentum exchange
10.4.3 Motor model
10.4.4 Reaction-wheel state equations with current feedback
10.4.5 Tachometer
10.4.6 Friction
10.4.7 Zero crossings
10.4.8 Commutation
10.4.9 Suspensions
10.5 Control-moment gyro
10.5.1 Introduction
10.5.2 Modeling
10.5.3 Torque distribution
10.5.4 Single-axis control-moment gyros
10.6 Thrusters
10.6.1 Introduction
10.6.2 Pulsewidth modulation
10.6.3 Minimum impulse bit
10.6.4 Time constants
10.6.5 Fuel system
10.7 Magnetic torquers
10.7.1 The magnetic field
10.7.2 Magnetic torque
10.7.2.1 Torque production
10.7.2.2 Magnetic-torquer design
10.8 Solenoids
10.8.1 Introduction
10.8.2 Derivation of the equations of motion for a dual-coil solenoid
10.8.3 Derivation of the equations of motion for a single-coil solenoid
10.9 Stepping motor
10.10 Dampers
References
11 Sensors
11.1 Space story
11.2 Introduction
11.3 Types of sensors
11.4 Planetary optical sensors
11.4.1 Horizon sensors
11.4.2 Earth and planetary sensors
11.4.3 Scanning Earth sensor
11.4.4 Analog Sun sensors
11.4.5 Digital Sun sensors
11.5 Gyros
11.6 Other sensors
11.6.1 Magnetometers
11.6.2 Accelerometers
11.6.3 Potentiometers
11.6.4 Angle encoders
11.7 Star cameras
11.7.1 Pinhole camera
11.7.2 Optical errors
11.7.3 Imaging-chip errors
11.8 GPS
References
12 Attitude control
12.1 Space story
12.2 Introduction
12.3 Attitude control phases
12.4 Attitude control system
12.5 Single-axis control
12.6 Three-axis control
12.7 Gravity-gradient control
12.8 Nutation control
12.9 Momentum-bias Earth-pointing control
12.10 Mixed control
12.11 Magnetic-torquer-only control
12.11.1 BDot
12.12 Low-bandwidth small-angle control
12.13 Lyapunov control
12.14 Orbit-transfer maneuver
12.15 Docking
12.16 Command distribution
12.16.1 The optimal torque-distribution problem
12.16.2 Reaction wheels
12.16.3 Linear programming
12.17 Attitude profile design
12.17.1 Alignment method
12.17.2 Minimizing the separation angle between vectors
12.17.3 Computing the target-inertial vector
12.17.3.1 Sun pointing
12.17.3.2 Nadir pointing
12.17.3.3 Latitude–longitude pointing
12.17.3.4 Orbit-normal pointing
12.17.3.5 LVLH pointing
12.18 Actuator sizing
12.18.1 Maneuvers
12.18.2 Disturbances
References
13 Momentum control
13.1 Space story
13.2 Introduction
13.3 Momentum growth
13.4 Control algorithms
13.5 Control-torque generation
13.5.1 Thruster control
13.5.1.1 Direct
13.5.1.2 Off-pulsing
13.5.2 Magnetic control
13.5.2.1 Magnetic field
13.5.2.2 Instantaneous control
13.5.2.3 Individual torquer control
13.5.2.4 Average control
13.5.3 Solar and aerodynamic pressure
13.5.3.1 Introduction
13.5.3.2 Torque-equilibrium attitude
13.5.3.3 Momentum management with solar wings
13.5.3.4 Gravity-gradient momentum management
14 Attitude estimation
14.1 Introduction
14.2 Star sensor
14.3 Planet sensor
14.3.1 Acquisition
14.3.2 Roll and pitch measurements from a planet sensor
14.4 Sun sensor
14.5 Magnetometer
14.6 GPS
14.7 Earth/Sun/magnetic field
14.8 Noise filters
References
15 Recursive attitude estimation
15.1 Introduction
15.2 Batch methods
15.3 Vector measurements
15.4 Disturbance estimation
15.5 Stellar-attitude determination
15.5.1 Introduction
15.5.2 Gyro-based attitude determination
15.5.3 A single-axis Kalman filter with a gyro
15.5.4 Star identification
15.6 Kalman filter with roll, pitch, and yaw and a gyro
15.7 Kalman filter with a quaternion measurement
16 Simulation
16.1 Space story
16.2 Introduction
16.3 Digital simulation
16.3.1 Numerical errors
16.3.2 Model truncation
16.4 Applications of simulation
16.4.1 A sequence of simulations for ACS development
16.4.2 Analysis support
16.4.2.1 Sizing of a reaction wheel
16.4.2.2 Disturbance modeling
16.4.2.3 Control design
16.4.2.4 End-to-end testing
16.4.3 Performance verification
16.4.3.1 Single case
16.4.3.2 Grid test
16.4.3.3 Numerical gain and phase margins
16.4.3.4 Monte Carlo
16.4.3.5 Commands
16.4.3.6 Edge cases and stress cases
16.4.3.7 Failure cases
16.4.4 Interface verification
16.4.5 Operator training
16.4.6 Anomaly investigations
16.5 Artificial damping
References
17 Testing
17.1 Space story
17.2 A testing methodology
17.3 Reliability
17.3.1 Requirements flow and testing
17.3.2 Testing lifecycle for the ACS flight software
17.4 Flight-vehicle control-system testing
17.5 Test levels (preflight)
17.6 Test levels (flight)
17.7 Simulations
17.8 Software-development standards
References
18 Spacecraft operations
18.1 Space story
18.2 Introduction
18.3 Preparing for a mission
18.4 Elements of flight operations
18.5 Mission-operations timeline
18.6 Mission-operations entities
18.7 Mission-operations preparation
18.8 Mission-operations organization
18.9 Mission-control center
18.10 Mission-operations example
19 Passive control-system design
19.1 Introduction
19.2 ISS orbit
19.3 Gravity gradient
19.4 Simulations
20 Spinning-satellite control-system design
20.1 Introduction
20.2 Spinning-spacecraft operation
20.3 Transfer orbit
20.4 Spinning transfer orbit
20.4.1 Dynamics
20.4.2 Actuators and sensors
20.4.3 Changing the spin rate
20.4.4 Spin-axis reorientation
20.4.5 Attitude determination
20.4.6 Delta-V engine firing
References
21 Geosynchronous-satellite control-system design
21.1 Space story
21.2 Introduction
21.3 Requirements
21.4 The design process
21.5 Mission-orbit design
21.6 The geometry
21.7 Control-system summary
21.8 A mission architecture
21.9 Design steps
21.10 Spacecraft overview
21.11 Disturbances
21.12 Acquisition using the dual-spin turn
21.12.1 Dynamics
21.12.2 Actuators and sensors
21.12.3 Initialization
21.12.4 Simulation
21.12.5 Pitch acquisition
21.13 Dynamics
21.13.1 Introduction
21.13.2 Normal operations
21.13.3 Dual-spin stability
21.13.4 Station-keeping operations
21.13.5 Actuators and sensors
21.13.6 Control-system organization
21.13.7 Modes
21.13.8 Earth sensor
21.13.9 Gyros
21.13.10 Noise filtering
21.13.11 Momentum-wheel pitch and tachometer loops
21.13.12 Low-bandwidth roll/yaw control
21.13.13 Thruster control
21.13.14 High-bandwidth roll/yaw and pitch control
21.13.15 Magnetic-torquer control
21.13.16 Thruster control
21.13.17 Actuator saturation
21.13.18 Thruster resolution
21.14 Summary
References
22 Sun-nadir pointing control
22.1 Space story
22.2 Introduction
22.3 Coordinate frames
22.4 Sun-nadir pointing
22.5 Components
22.5.1 Sensors
22.5.2 Actuators
22.6 Attitude determination
22.6.1 Roll
22.6.2 Pitch
22.6.3 Sun-sensor eye preprocessing
22.6.4 Solar-array pitch
22.6.5 Yaw
22.7 Control
22.7.1 Reaction-wheel loop
22.7.2 Attitude loop
22.7.3 Solar-array control
22.7.4 Momentum control
23 Lander control
23.1 Space story
23.2 Landers
23.3 Landing concept of operations
23.4 Selenographic coordinates
23.5 Linear-tangent guidance law
23.6 Lunar-lander model
23.7 Optimal descent
23.8 Descent control
23.9 Terminal control
23.10 Altitude hold
23.11 Bang-bang landing algorithm
23.12 Simulation results
References
24 James Webb Space Telescope ACS design
24.1 Requirements
24.2 Spacecraft model
24.3 Disturbances
24.4 Attitude maneuvers
24.5 Momentum control
24.6 Attitude control
24.7 Torque distribution
24.8 Attitude determination
24.9 Simulation
References
25 CubeSat control system
25.1 Space story
25.2 Introduction
25.3 Requirements
25.4 Actuator and sensor selection
25.5 Design
25.6 Control-system design
25.7 Attitude determination
25.8 Simulation
26 Microwave Anisotropy Satellite
26.1 The WMAP mission
26.2 ACS overview
26.3 Control modes
26.4 Sensing and actuation
26.5 Control-system design
26.6 Nested loops
26.7 Simulation results
References
27 Solar sails
27.1 Introduction
27.2 Gyrostat with a moving mass
27.3 Thin-membrane model
27.4 Momentum control
27.5 Attitude control
27.6 Architecture
References
A Math
A.1 Vectors and matrices
A.1.1 Notation
A.1.2 Vector and matrix representations of operations
A.1.3 Matrix operations
A.1.4 Special matrices
A.1.5 Useful matrix–vector identities
A.2 Numerical integration
A.2.1 Linearizing a system
A.2.2 Nonlinear
A.2.2.1 Numerical integration methods
A.2.3 Discontinuities
A.3 Fourier series
A.3.1 Trigonometric identities
A.3.2 Sine and cosine Fourier series
A.4 Spherical geometry
A.5 The chain rule in calculus
B Probability and statistics
B.1 Space story
B.2 Introduction
B.3 Axiomatic probability
B.4 Binomial theorem
B.5 Probability distributions
B.6 Evaluating measurements
B.7 Combining errors
B.8 Multivariate normal distributions
B.9 Random signals
B.10 Outliers
B.11 Noise models
B.12 Monte Carlo methods
References
C Time
C.1 Time scales
C.2 Earth rotation
C.3 Julian date
C.4 Time standards
C.4.1 Local time
C.4.2 UTC
C.4.3 GPS
C.4.4 Loran-C
C.4.5 TAI
C.4.6 Planetary days
References
D Coordinate systems
D.1 Earth-centered inertial coordinates
D.2 Local vertical/local horizontal coordinates
D.3 Heliocentric coordinates
D.4 International Space Station coordinates
D.5 Selenographic frame
D.6 Areocentric (Mars) coordinates
E Ephemeris
E.1 Introduction
E.2 Planetary orbits
E.3 Asteroid orbits
E.4 Planetary orientation
E.5 Asteroid dynamics
E.6 Stars
References
F Laplace transforms
F.1 Using Laplace transforms
F.2 Useful transforms
G Control theory
G.1 Introduction
G.2 Simple control system
G.3 The general control system
G.4 Fundamental relationships
G.5 Tracking errors
G.6 State-space closed-loop equations
G.7 Approaches to robust control
G.7.1 Introduction
G.7.2 Modeling uncertainty
G.7.3 Control-structure design
G.7.4 Nyquist-like techniques
G.7.5 LQG methods
G.7.6 H∞ and μ synthesis
G.8 Single-input–single-output control design
G.8.1 Introduction
G.8.2 Elementary loop compensation
G.8.2.1 First-order compensators
G.8.2.2 Generalized integrator
G.8.2.3 Gain compensation of a double-integrator plant
G.8.2.4 More complex compensation of a double-integrator plant
G.9 Digital control
G.9.1 Introduction
G.9.2 Modified continuous design
G.9.2.1 Introduction
G.9.2.2 The sampler
G.9.2.3 The delay
G.9.2.4 The zero-order hold
G.9.2.5 Pulsewidth modulation
G.10 Continuous-to-discrete transformations
G.10.1 The difference equation
G.10.2 Transforming from the s plane to the z plane
G.10.3 Transformation of a differentiator
G.10.4 State estimator
G.11 Flexible-structure control
G.11.1 Introduction
G.11.2 Two coupled inertias
G.11.3 Double integrator
G.11.4 Control algorithms
G.11.5 Lead compensation of the minimum-phase system
G.11.6 Noncollocated sensor and actuator
G.12 Model-following control
G.13 Double-integrator control
G.13.1 Introduction
G.13.2 Linear control
G.13.3 Phase-plane controller
G.13.4 Control limiting
G.13.5 Cross-axis coupling
G.14 Lyapunov control
G.14.1 Background
G.14.2 Theory
G.14.3 Nonlinear rate damper
G.15 First- and second-order systems
G.16 Inner and outer loops
H Estimation theory
H.1 Estimation theory
H.1.1 Conversion from continuous to discrete time
H.2 The Kalman-filter algorithm
H.3 Bayesian derivation
H.4 Extended Kalman filter
H.5 Unscented Kalman filter
H.6 UKF state-prediction step
H.7 Kalman-filter example
H.7.1 Dynamical and measurement model
H.7.2 Linear Kalman filter
H.7.3 Extended Kalman filter
H.7.4 Unscented Kalman filter
References
I Orbit theory
I.1 Space story
I.2 Introduction
I.3 Representations of orbits
I.3.1 Orbital geometry
I.3.2 Cartesian coordinates
I.3.3 Keplerian elements
I.3.4 Equinoctial elements
I.4 Propagating orbits
I.4.1 Introduction
I.4.2 Kepler propagation
I.4.3 Numerical integration
I.5 Gravitational acceleration
I.5.1 Point masses
I.5.2 Planetary asymmetries
I.6 Linearized orbit equations
J Optics
J.1 Optical sensors
J.1.1 Optical nomenclature
J.1.2 Telescope types
J.1.3 Geometry of imaging
J.1.4 Telescope performance
J.1.4.1 Geometric
J.1.4.2 Errors
J.1.5 Pinhole camera
J.2 Radiometry
J.2.1 Mathematical basis for position and attitude determination using a camera
J.2.2 Basic radiometry
J.2.3 Radiosity
J.2.4 Radiometric sources
J.2.5 Noise and performance factors
J.2.5.1 Fill factor
J.2.5.2 Illumination side
J.2.6 Dynamic range
J.2.7 Blooming
J.2.8 Quantum efficiency
J.2.8.1 Dark current
J.2.8.2 Fixed-pattern noise
J.2.8.3 Readout noise
J.2.8.4 Radiation hardness
J.2.9 Imaging-chip theory
J.2.9.1 Dark current
J.2.9.2 Cosmic rays
J.2.9.3 Thermal noise
J.2.9.4 Transfer efficiency
J.2.9.5 Reset noise
J.2.9.6 Photon noise
J.2.9.7 Quantization noise
J.2.9.8 Total noise
J.2.9.9 Blooming
J.2.9.10 Linearity
J.2.9.11 Amplifier noise
J.2.10 Data reduction
References
K Star-camera algorithms
K.1 Space story
K.2 Introduction
K.3 Center-of-mass star centroiding
K.3.1 Background noise
K.3.2 Creating a star blob
K.3.3 Center-of-mass
K.4 Star identification
K.4.1 Catalog processing
K.4.2 Sorting star pairs with k-vector
K.5 Fine centroiding
References
L Magnetic-hysteresis damping
L.1 Magnetic-hysteresis damper model
L.2 Energy-dissipation analysis
References
M Machine intelligence
M.1 Space story
M.2 Introduction
M.3 Branches of machine intelligence
M.4 Stored command lists
M.5 Deep Space 1
M.6 Neural networks
M.7 Static Earth sensors
M.8 Expert systems
M.9 Reinforcement learning
M.9.1 Introduction
M.9.2 Optimal attitude trajectory
M.9.3 Single-axis optimal attitude trajectory
References
N Glossary of acronyms
Index