Overview
The CIRCLE parameter group configures the behavior of the Circle flight mode. In this mode, the vehicle flies a perfect circle around a center point (typically the location where the mode was engaged) while keeping the nose pointed towards the center (ROI).
Key Concepts
1. Radius and Direction
CIRCLE_RADIUS: Defines the size of the circle (in centimeters or meters depending on firmware version, typically cm).CIRCLE_RATE: Defines the angular speed of the orbit (deg/s).CIRCLE_DIR: 0 = Clockwise, 1 = Counter-Clockwise. (Note: Often controlled by the sign ofCIRCLE_RATEin newer versions).
2. Point of Interest
By default, the vehicle faces the center.
CIRCLE_OPTIONS: Can be used to change facing behavior (e.g., face direction of flight).
Parameter Breakdown
CIRCLE_RADIUS: Radius of the orbit.CIRCLE_RATE: Angular velocity (deg/s). High rate + small radius = fast flight.
Integration Guide
- Engagement: Fly to the desired center point, switch to
CIRCLE. The vehicle will fly out toCIRCLE_RADIUSand begin orbiting. - Adjustment: In Copter, you can often adjust the radius dynamically using the Pitch/Roll stick while in Circle mode.
Developer Notes
- Library:
ArduCopter/mode_circle.cpp,ArduPlane/mode_circle.cpp. - Difference: Plane often uses
LOITER_RADIUSfor standard loiters, butCIRCLEmode is specific.