ADCS

Attitude Determination and Controls Subsystem

Precision attitude control for stable imaging and communication operations.

Overview

The Attitude Determination and Controls Subsystem (ADCS) maintains satellite orientation using sensors and actuators for precise pointing. It enables stable imaging operations and optimal antenna alignment for ground communication.

Our ADCS features an IMU with integrated sensor fusion, coupled with a GPS module for position determination. The B-dot controller algorithm handles initial detumbling after deployment, using magnetorquers with PWM control signals to interact with Earth's magnetic field.

Specifications

ParameterValue
SensorsIMU with magnetometer, gyroscope, accelerometer
GPS/GNSS ReceiverIntegrated GPS module
ActuatorsMagnetorquers, Reaction Wheels
AlgorithmB-dot Controller, PID Control
EstimationKalman Filters
Stabilization3-axis

System Components

Sensors

IMU with magnetometer, gyroscope, and accelerometer for attitude sensing. Provides 9-DOF motion data with sensor fusion.

Estimation of Sensor Data

Using Kalman Filter to estimate true state from noisy and incomplete sensor measurements.

Actuators

Magnetorquers with PWM control for attitude adjustment using Earth's magnetic field. Reaction Wheels for precise attitude control by taking advantage of Newton's third law of motion. Four reaction wheels in a tetrahedral arrangement for redundancy and fault tolerance, ensuring 3-axis control in case one fails.

GPS Module

Position determination for orbital mechanics calculations and timing synchronization with ground stations.