Notetaker: Control Subsystems Flashcards
Identify
Manages and regulates a process output based on inputs into the process
Control Systems
What are the steps of Open-Loop Controls?
- Input
- Controller
- Actuator
- Output
What are the steps of Closed-Loop Controls?
- Input
- Controller
- Actuator
- Output
- Feedback
Identify
Responsible for satellite attitude (“rotational”) control; where the satellite is pointing or focused
Attitude Determination and Control Subsystem (ADCS)
Identify
Responsible for satellite orbit control; where the satellite is heading or what path it is on
Guidance, Navigation, and Control Subsystem (GNC)
What controls and monitors the rotation of the satellite?
Attitude Determination and Control System (ADCS)
What ensures antennas pointed at ground station, payload pointed in the right direction, and component temperatures maintained by point spacecraft face toward/away from the sun?
Attitude Determination and Control System (ADCS)
What are the components of the Attitude Determination and Control System (ADCS)?
- Controller
- Instruments
- Sensors
Attitude determination must be performed where?
On-Board
Identify
How we determine attitude
Attitude Sensors
What are the “eyes” of ADCS?
- Earth Sensors
- Sun Sensors
- Star Sensors
What is the “Inner Ear” of ADCS?
- Gyroscopes
- Magnetometers
What is the other sensor of ADCS?
- Global Navigation Satellite System (GNSS) Receiver
What are the “brains” of ADCS?
Attitude Controllers
Identify
Takes inputs from the sensors and generates commands
ADCS
Attitude Controllers
Identify
The “hands” of the system
ADCS
Attitude Instruments
Identify
Takes commands from the controller and provides “torque on demand” to control satellite attitude
ADCS
Attitude Instruments
How do Passive Instruments “inner ear” work?
ADCS
Uses natural phenomenas (gravity, angular momentum, etc)
How do Active Instruments “hands” work?
ADCS
Turned on and off by controller (requires power to operate)
What are 3 Passive Instruments?
ADCS
- Gravity-Gradient Stabilization
- Spin Stabilization
- Dampers
What are 3 Active Instruments?
ADCS
- Thrusters
- Magnetic Torquers
- Momentum-Control Devices
What controls and monitors the orbit of the satellite?
Guidance, Navigation, and Control Subsystem (GNC)
What is the position and velocity with respect to the earth?
Orbit
What is known as “the actuators?”
GNC
Guidance
What is known as “the sensors?”
GNC
Navigation
What is known as the “brain of the system?”
GNC
Control
Identify
Utilizes the Propulsion Subsystem
GNC
Guidance
Identify
Generates thrust in a specific direction
GNC
Guidance
Identify
Two primary concerns:
* Velocity Vector (V)
* Position Vector (R)
GNC
Navigation
Identify
Two navigation systems:
* On-Board
* Off-Board
GNC
Navigation
Identify
Compares current position and velocity (Vcurrent) to desired position and velocity (Vdesired)
GNC
Control
Identify
Sends commands to the actuators
GNC
Control
Processed INTERNALLY is called?
GNC
On-Board
Processed EXTERNALLY is called?
GNC
Off-Board
Identify
Measures the range between GPS and the receiver
GNC
GNSS Receiver
Identify
Performs triangulation
GNC
Earth, Sun, and/or Star Sensors
Identify
Utilizing Newton’s Laws to determine the current position and velocity (uses accelerometers and gyroscopes)
GNC
Inertial Sensors
Identify
When a spacecraft passes over an RTS, the RTS can provide ranging
GNC
RTS Ranging
Identify
Supplemented by SSN observations
GNC
Space Surveillance Network (SSN)
Identify
Extension of the SDA mission
GNC
Space Domain Awareness (SDA)
