This section describes the coordinate system and units used to determine the position of the drone, including the definition of the origin point.
| Attribute | Description |
|---|---|
| Coordinate System | Ground Coordinate System (NED) |
| Unit | Meter |
| X | North (Distance towards the North) |
| Y | East (Distance towards the East) |
| Z | Down (Distance downwards, height from ground) |
- Ground Coordinate System (NED): The NED coordinate system uses a ground-fixed reference frame, defining positions in terms of North (X), East (Y), and Down (Z) axes. This system is commonly used in aviation and helps in intuitively understanding the position of drones.
- The origin point is defined by the initial values of latitude, longitude, and altitude (ALT) provided. This origin serves as the reference point for all positional measurements of the drone in the NED coordinate system.
- In the NED coordinate system, positive values in the X and Y axes indicate a position to the North and East of the origin, respectively. For the Z axis, a positive value indicates a position below the origin point, aligning with the downward orientation of the Z axis in the NED system.
- Meter: The position of the drone along each axis is measured in meters. This ensures precision in positioning, conforming to international standards.
This section outlines the coordinate system and units used for measuring the drone's velocity, along with relevant details.
| Attribute | Description |
|---|---|
| Coordinate System | Ground Coordinate System (NED) |
| Unit | Meters per Second (m/s) |
| X | Velocity towards the North |
| Y | Velocity towards the East |
| Z | Velocity downwards (towards the ground) |
- Ground Coordinate System (NED): For velocity measurements, the NED coordinate system is used. In this system, the axes are oriented North (X), East (Y), and Down (Z), effectively representing the drone's movement in three-dimensional space.
- Meters per Second (m/s): The velocity of the drone is measured in meters per second. This unit is the standard for speed measurement, offering a clear and consistent way to gauge how fast the drone is moving in each direction.
- The velocity data represents the rate of change of position along each axis of the NED coordinate system. Positive values in the X and Y axes indicate movement towards North and East, respectively. For the Z axis, a positive value indicates movement downwards (towards the ground), in line with the orientation of the NED coordinate system.
This section outlines the coordinate system and units used for measuring the drone's velocity in relation to its body frame, along with relevant details.
| Attribute | Description |
|---|---|
| Coordinate System | Body Coordinate System (FRD) |
| Unit | Meters per Second (m/s) |
| X | Velocity in the forward direction (nose) |
| Y | Velocity towards the right wing |
| Z | Velocity downwards (relative to aircraft body) |
- Body Coordinate System (FRD): For velocity measurements relative to the drone's body, the FRD coordinate system is used. This system is oriented Forward (X), Right (Y), and Down (Z), directly corresponding to the drone's own axes and the pilot's perspective.
- Meters per Second (m/s): The drone's velocity is measured in meters per second relative to its own body axes. This measurement is crucial for understanding the drone's movement with respect to its current orientation.
- Velocity data in the body frame represents the rate of change of position along the drone's own axes. A positive X-axis value indicates forward movement, a positive Y-axis value indicates a movement to the right, and a positive Z-axis value denotes a downward movement, all relative to the aircraft's body.
Understanding the drone's velocity in the body frame is essential for flight control systems, autopilot navigation, and stabilization algorithms.
This section details the orientation of the drone, described in terms of angles along the NED coordinate system axes, and measured in radians.
| Attribute | Description |
|---|---|
| Coordinate System | Ground Coordinate System (NED) |
| Unit | Radian |
| Roll | Rotation around the X-axis (North) |
| Pitch | Rotation around the Y-axis (East) |
| Yaw | Rotation around the Z-axis (Down) |
- Ground Coordinate System (NED): The NED system is used to describe the orientation of the drone. In this system, roll, pitch, and yaw angles are defined relative to the North (X), East (Y), and Down (Z) axes respectively.
- Radian: Angles are measured in radians, providing a standard and precise way to quantify rotation. One full rotation (360 degrees) equals 2π radians.
- Roll: A positive roll angle indicates a clockwise rotation when viewed from the rear, tilting the right wing down and the left wing up.
- Pitch: A positive pitch angle denotes the nose of the drone tilting up.
- Yaw: A positive yaw angle signifies a clockwise rotation when viewed from above, turning the drone to the right.
These angular orientations help in understanding the drone's attitude in 3D space, crucial for navigation and control.
This section explains the measurement of the drone's , which is the rate of change of its angular position over time.
| Attribute | Description |
|---|---|
| Coordinate System | Ground Coordinate System (NED) |
| Unit | Radian per Second (rad/s) |
| Roll Rate | Angular velocity around the X-axis (North) |
| Pitch Rate | Angular velocity around the Y-axis (East) |
| Yaw Rate | Angular velocity around the Z-axis (Down) |
- Ground Coordinate System (NED): In this system, the is measured relative to the North (X), East (Y), and Down (Z) axes, corresponding to roll, pitch, and yaw movements.
- Radian per Second (rad/s): Angular velocity is measured in radians per second. This unit quantifies how quickly the drone is rotating about each of the three axes.
- Roll Rate: A positive value indicates a clockwise rotation around the X-axis when viewed from the rear.
- Pitch Rate: A positive value denotes a nose-up rotation around the Y-axis.
- Yaw Rate: A positive value signifies a clockwise rotation around the Z-axis when viewed from above.
Understanding these rates of is crucial for controlling the drone's orientation and for stabilizing its flight.
This section explains the measurement of the drone's in the body coordinate system, which is the rate of change of its angular position over time, relative to its own body axes.
| Attribute | Description |
|---|---|
| Coordinate System | Body Coordinate System (FRD) |
| Unit | Radian per Second (rad/s) |
| Roll Rate | Angular velocity around the forward (X) axis |
| Pitch Rate | Angular velocity around the right (Y) axis |
| Yaw Rate | Angular velocity around the downward (Z) axis |
- Body Coordinate System (FRD): In this system, is measured relative to the aircraft's own Forward (X), Right (Y), and Downward (Z) axes, which align with the fuselage of the aircraft.
- Radian per Second (rad/s): Angular velocity is measured in radians per second. This unit quantifies the rate at which the drone is rotating about its own body axes.
- Roll Rate: A positive value indicates a rotation to the right around the drone's longitudinal axis.
- Pitch Rate: A positive value denotes a nose-up rotation around the drone's lateral axis.
- Yaw Rate: A positive value signifies a rotation to the right around the drone's vertical axis.
Understanding the drone's in the body frame is essential for maneuvers, orientation control, and the stabilization of the aircraft during flight.
This section describes the variation in rotor speed, a critical parameter for understanding and managing the drone's flight dynamics.
| Attribute | Description |
|---|---|
| Unit | Revolutions per Minute (RPM) |
| Description | The rate of change in the drone's rotor speed, directly influencing lift and flight stability |
- Rotor Speed: Indicates the rate of change in the rotational speed of the drone's rotors. It is a key determinant of the drone's lifting capability, stability, and agility.
- Revolutions per Minute (RPM): Measures the frequency of the rotor's complete revolutions in one minute. This unit provides a direct indication of how quickly the rotor speed is increasing or decreasing.
- A positive RotorSpeed value signifies an increase in rotor speed, typically associated with an increase in lift and the drone's potential to ascend.
- A negative RotorSpeed value indicates a decrease in rotor speed, corresponding to a reduction in lift and the drone's potential to descend.
Comprehending these changes in rotor speed is crucial for the effective control of the drone's altitude and stability during various flight maneuvers.
This section explains how the rotors' speed translates into thrust, which is essential for the drone's vertical movement.
| Attribute | Description |
|---|---|
| Unit | Newton (N) |
| Description | The force exerted by the rotors to lift the drone against gravity |
- Thrust: The upward force generated by the rotors, crucial for lift-off, hovering, and ascending motions.
- Newton (N): The SI unit of force, measuring the amount of force exerted. For drones, it equates to the force required to accelerate the drone's mass.
- Greater thrust than the drone's weight results in ascending motion.
- Less thrust than the drone's weight causes descending motion.
- Equal thrust and weight allow for hovering at a constant altitude.
Understanding thrust dynamics is essential for managing the drone's lift and ensuring stable flight.
This section delves into the torques generated by rotor motion that affect the drone's orientation and stability.
| Attribute | Description |
|---|---|
| Unit | Newton-meter (Nm) |
| Description | The rotational force that influences the drone's yaw, pitch, and roll |
- Torque: The measure of rotational force produced by the rotors that contributes to the drone's turning and angular orientation.
- Newton-meter (Nm): The SI unit of torque, representing the force applied at a distance from the rotation axis.
Torque plays a crucial role in controlling the attitude of a drone. The following rotational torques along different axes are considered:
- Roll Torque (φ direction): The force that rotates the drone around its lateral axis (side to side).
- Pitch Torque (θ direction): The force that rotates the drone around its longitudinal axis (front to back).
- Yaw Torque (ψ direction): The force that rotates the drone around its vertical axis (up and down).
These torques are controlled by the forces generated by the drone's rotors. By adjusting the speed and direction of rotation of the rotors, the drone can modulate the torque around each axis to achieve the desired changes in posture.
The drone's flight control system precisely adjusts these torques to realize specific attitudes and flight patterns. Understanding and controlling these torques are essential for stable flight and precise maneuvers.