Introduction¶

Quadcopter (X-Mode) using RTOS.

Insert picture of build

Control loop: PI-PI.

D Gain will not be used as data is noisy and caused instability shortly after liftoff.

Implementation¶

RTOS¶

4 main threads:

• Thread1: Output telemetry.
  • Outputs: YPR, Gyro, Altitude, Voltage, RC Input, RC Command, PID output, ESC Power
  • Thread frequency: 50Hz.

• Thread 2-Master: YPR sample, PI Master/Outer control loop. Attitude control.
  • Subfunction: Sample MPU6050 and calculate Yaw Pitch Roll angles from DMP quaternion.
    • Settings: 50Hz sampling rate (Attitude), 100Hz output FIFO buffer.
  • Settings: Input limits: -500.0, 500.0; Output limits: -200.0, 200.0; Output bias: 0.0, Automatic mode
  • Settings: KP: 0.5, TI: 1.0, TD = 0.0
  • Thread frequency: 200Hz

• Thread 2-Slave: Gyro sample, PI Slave/Inner control loop. Rate control.
  • Settings: Input limits: -500.0, 500.0; Output limits: -200.0, 200.0; Output bias: 0.0, Automatic mode
  • Settings: KP: 7.0, TI:2.0, TD = 0.0
  • Thread frequency: 400Hz

• Thread 3: RC & Bluetooth Command
  • Settings: Default quadcopter is unarmed
  • Thread frequency: 50Hz

• Thread 4: Update ESC pulsewidth
  • Note: My ESCs can apparently handle refresh rates of up to 400Hz. This means that the ESC should handle a 400Hz PWM pulse. This is distinguished from how fast I update the actual pulsewidth/duty cycle of my pulse!!!
  • Settings: PWM frequency: 400Hz
  • Thread frequency: 400Hz.

AHRS Sampling¶

Thread frequency: 200Hz

MPU6050 Sampling rate: 100Hz

FIFO Buffer Output rate: 100Hz

To be completed

Gyro Sampling & PID calculations¶

Master PID Loop¶

Thread frequency: 200Hz Control: PI

To be completed

Slave PID Loop¶

Thread frequency: 400Hz Control: PI

To be completed

RC & Bluetooth Command¶

Thread frequency: 50Hz

To be completed

Update ESC¶

Thread frequency: 400Hz

Pulse period: 400HZ

Pulse update rate = Thread frequency = 400Hz

To be completed