Position controller gains and parameters (so3_control)

Our position controller requires two parameters to be configured:

• Thrust/rpm and rpm/throttle parameters
• PID Gains

Propeller coefficients

TODO: Alex could you write something/point to some resources about how to find these

You will need to update the following propeller parameters in SO3_command_to_mavros.launch (here)

(1) Thrust vs RPM parameters, according to the following equation: Thrust = a * RPM^2 + b * RPM + c (thrust is in Newton not grams-force)

<arg name="thrust_vs_rpm_coeff_a" default="8.401e-7"/>
<arg name="thrust_vs_rpm_coeff_b" default="-1.400e-3"/>
<arg name="thrust_vs_rpm_coeff_c" default="1.12"/>

(2) RPM vs Throttle parameters

<arg name="rpm_vs_throttle_coeff_a" default="6000"/>
<arg name="rpm_vs_throttle_coeff_b" default="0"/>

PID Control Gains

used gains:
  pos: {x: 7.4, y: 7.4, z: 10.4}   # position gains
  vel: {x: 4.8, y: 4.8, z: 6.0}    # velocity gains
  ki:  {x: 0.00, y: 0.00, z: 0.00} # position error integral gains

unused gains:
  kib: {x: 0.00, y: 0.00, z: 0.00} # body-frame position error integral gains, NOT used in so3_control control calculation
  rot: {x: 1.5, y: 1.5, z: 1.0}    # rotation gains, only used in so3_trpy_control, NOT used in so3_control
  ang: {x: 0.13, y: 0.13, z: 0.1}  # angular velocity gains, only used in so3_trpy_control, NOT used in so3_control

unused corrections: # corrections are only used in so3_trpy_control, NOT used in so3_control
  kf: 0.0e-08
  r: 0.0
  p: 0.0

max_pos_int:   0.5 #  position error integral term limit, if ki=0, this term is not important
max_pos_int_b: 0.5 # body-frame position error integral term limit, NOT used in actual control calculation