controls

What are control loops in UAVs?

Cascaded loops that convert position commands into motor outputs.

What is the typical control loop structure?

Position → velocity → attitude → rate → motor commands.

Why use cascaded control loops?

To break complex control into stable, manageable layers.

What does the attitude controller do?

Controls the drone’s orientation (roll, pitch, yaw).

What does the rate controller do?

Controls angular velocity for precise stabilization.

What does the P term do?

Provides immediate response to error.

What does the I term do?

Corrects long-term accumulated error.

What does the D term do?

Dampens oscillations by reacting to error rate.

What happens if P is too high?

Oscillations and instability.

What happens if D is too high?

Noisy response and overheating motors.

What happens if I is too low?

Drift and inability to hold position.

What is rate control?

Controls angular velocity (used in acro mode).

What is angle control?

Controls orientation relative to horizon (self-leveling).

When do you use rate mode?

For FPV/manual flying.

When do you use angle mode?

For stable or beginner flight.

What is feedforward in control systems?

Predictive control based on input rather than error.

Why use feedforward?

Improves responsiveness and reduces delay.

What is stability?

The system’s ability to remain controlled without oscillations.

What is responsiveness?

How quickly the system reacts to inputs.

Tradeoff between stability and responsiveness?

More responsiveness can reduce stability if not tuned properly.

What causes oscillations?

High P gain, noise, or poor tuning.

How do you fix oscillations?

Reduce P gain or increase D gain.

What is high-frequency oscillation?

Rapid vibrations caused by noise or over-tuning.

What does ESC do?

Controls motor speed based on commands from the flight controller.

Why is ESC response important?

Faster response improves control accuracy.

What affects motor response?

ESC firmware, motor quality, and battery performance.

How does payload affect control?

Increases inertia and reduces responsiveness.

What must be adjusted when adding payload?

PID tuning and throttle scaling.

Why does payload cause instability?

Changes center of gravity and system dynamics.

What is manual mode?

Full pilot control with no stabilization.

What is stabilize mode?

Auto-leveling with manual input.

What is auto mode?

Fully autonomous flight using waypoints.

What is a failsafe?

Safety mechanism triggered during system failure.

What triggers failsafe?

Signal loss, low battery, or sensor failure.

What happens during failsafe?

Drone may return home, land, or hover.