quadcopter_basic.ipynb

[shclift]

• pyadrc version: 0.3.0 - 0.4.1
• Python version: 3.9.16
• Operating System: Win 10

Description

1. Need to change t_settle to w_cl for more recent pyadrc versions.
2. The disturbance rejection example seems to have problems for versions > 0.3.0

What I Did

Ran the Jupyter notebook for the different releases. With 0.3.0 I get this:

With 0.3.1 and more recent versions I get this:

Am I doing something wrong?

[shclift]

I think I found the problem:

...
# self._update_eso(y, u) # <<< Wrong place for this?

    if self.inc_form is False:
        u = (self.Kp / self.b0) * r - self.w.T @ self.xhat
        u = self._limiter(u)
    else:  # self.inc_form is True:
        delta_r = r - self.rkm1
        delta_u = ((self.Kp / self.b0) * delta_r
                   - self.w.T @ self.xhat_delta)
        u = delta_u

        self.rkm1 = r

    self._update_eso(y, u)

...

Seems to work with the ESO update moved after the calculation of u - same as 0.3.0.

[s03311251]

Were you referring to these lines? I also experience a similar problem with the latest version (0.4.1).

pyadrc/docs/notebooks/quadcopter_basic.ipynb

Lines 101 to 103 in 0629122

	"adrc = pyadrc.StateSpace(order=2, delta=delta,\n",
	" b0=1/0.028, t_settle=0.5, k_eso=10)"
	]

The jyputer notebook is not execuable anymore, because t_settle was, but no longer is the input parameter of constructor.
Previous version:

pyadrc/pyadrc/pyadrc.py

Lines 71 to 80 in 7880677

	def __init__(self,
	order: int,
	delta: float,
	b0: float,
	t_settle: float,
	k_eso: float,
	eso_init: np.array = False,
	r_lim: tuple = (None, None),
	m_lim: tuple = (None, None),
	half_gain: tuple = (False, False)):

Current version:

pyadrc/pyadrc/pyadrc.py

Lines 87 to 97 in 0629122

	def __init__(self,
	order: int,
	delta: float,
	b0: float,
	w_cl: float,
	k_eso: float,
	inc_form: bool = False,
	eso_init: tuple = False,
	r_lim: tuple = (None, None),
	m_lim: tuple = (None, None),
	half_gain: tuple = (False, False)):

now t_settle = 4 / w_cl, hence I think the lines should be changed as following:

  "adrc = pyadrc.StateSpace(order=2, delta=delta,\n", 
  "                         b0=1/0.028, w_cl=4/0.5, k_eso=10)" 
 ] 

[s03311251]

An off-topic comment, if you're updating the file, could you please update this line too? There's a typo in \frac

pyadrc/docs/notebooks/quadcopter_basic.ipynb

Line 201 in 0629122

"Lets assume something went horribly wrong during tuning and we have chosen a modelling parameter that is 50% off of the actual value, i.e. $b_0 = /frac{1}{0.028/2}$."

It would be clearer if it is expressed as $b_0 = \frac{1}{2} \frac{1}{0.028}$