Drone Control Methods

Crazyflie 2.0 flight controller (PD/LQR) with polynomial trajectory generation and hardware validation

Directory Structure

rbe-502-crazyflie-project/
├── gym_pybullet_drones/           # Main Python package
├── tests/                         # Unit tests
├── pyproject.toml                 # Python project configuration
├── README.md                      # Main project documentation
├── LICENSE                        # Project license
├── build_project.sh               # Build script

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Control Systems: gym_pybullet_drones/control/

DSLPIDControl.py

• Purpose: Implements cascaded PID control for position and attitude
• Key Classes: DSLPIDControl (inherits from BaseControl)
• Key Methods:
  • __init__(): Initialize controller with drone model
  • reset(): Reset PID integral and error states
  • computeControl(): Main control computation entry point
  • _dslPIDPositionControl(): Position/velocity control
  • _dslPIDAttitudeControl(): Attitude/angular control
  • _one23DInterface(): Convert 1/2/3D thrust to motor commands
• Tunable Parameters:
  • Lines ~205-210: Position control gains (Kp, Kd)
  • Lines ~306-307: Attitude control gains (Kp_att, Kd_att)
• Usage:

  ctrl = DSLPIDControl(drone_model=DroneModel.CF2X)
  rpm = ctrl.computeControl(...)

LQRControl.py

• Purpose: Linear Quadratic Regulator controller implementation
• Key Classes: LQRControl (inherits from BaseControl)
• Features: Optimal control using LQR theory
• Usage: Alternative to PID control for advanced users
• Tuning: Less intuitive than PID, requires understanding of LQR

Trajectory Generators: gym_pybullet_drones/trajectory/

circle.py

• Purpose: Generate circular flight trajectories
• Key Classes: Circle
• Key Methods:
  • get_pos(t): Get position at time t
  • get_vel(t): Get velocity at time t
  • get_acc(t): Get acceleration at time t
• Parameters:
  • center: Center point [x, y, z]
  • radius: Circle radius in meters
  • height: Hovering height in meters
• Usage:

  traj = Circle(center=[0, 0, 1.0], radius=0.5, height=1.0)
  pos = traj.get_pos(t=1.5)

diamond.py

• Purpose: Generate diamond-shaped flight trajectories
• Key Classes: Diamond
• Key Methods: Same as Circle class
• Parameters: Similar to Circle
• Usage: For testing different trajectory shapes

plotting.py

• Purpose: Visualization utilities for trajectories
• Key Functions:
  • Plot trajectory paths
  • Display 3D trajectory visualization
  • Export trajectory data
• Usage: For analyzing and debugging trajectories

Examples: gym_pybullet_drones/examples/

pid_1_drone.py

• Purpose: Single drone hovering with PID control
• What It Does:
  1. Creates a simulation environment
  2. Spawns one Crazyflie drone
  3. Uses DSLPIDControl for hovering
  4. Commands drone to hover at 1.0 m height
  5. Runs for ~5 seconds
• Running:

  cd gym_pybullet_drones/examples
  python3 pid_1_drone.py

• Good For: Testing if installation works, basic PID testing
• Output: Visual simulation window

trajectory_tracking.py

• Purpose: Track predefined trajectories (circular or diamond)
• What It Does:
  1. Creates simulation environment
  2. Generates circular or diamond trajectory
  3. Commands drone to follow trajectory
  4. Visualizes in real-time
  5. Logs trajectory tracking error
• Running:

  cd gym_pybullet_drones/examples
  python3 trajectory_tracking.py

• Good For: Testing trajectory tracking performance
• Output: Visual simulation + performance metrics