Black-Nichols diagram of a linear dynamical system
black(sl) black(sl, fmin, fmax) black(sl, fmin, fmax, step) black(sl, frq) black(frq, db, phi) black(frq, repf) black(.., comments)
A siso or simo linear dynamical system, in state space, transfer function or zpk representations, in continuous or discrete time.
real scalars (frequency bounds)
row vector or matrix (frequencies)
row vectors or matrices of modulus (in dB) and phases (in degrees). One row for each response.
row or matrix of complex frequency response(s). One row for each response.
real: (logarithmic) discretization step. See calfrq for the choice of default value.
vector of character strings: captions.
Black's diagram (Nichols'chart) for a linear dynamical system .
sl
can be a continuous-time or
discrete-time SIMO system given by its state space,
rational transfer function (see syslin) or zpk representation. In case of
multi-output the outputs are plotted with different
colors.
The frequencies are given by the bounds
fmin
,fmax
(in Hz) or
by a row-vector (or a matrix for multi-output)
frq
.
To plot the grid of iso-gain and iso-phase of
y/(1+y)
use nicolschart().
Default values for fmin
and
fmax
are 1.d-3
,
1.d+3
if sl
is continuous-time or
1.d-3
, 0.5
/sl.dt (nyquist frequency)
if sl
is discrete-time.
//Black diagram s=poly(0,'s'); sl=syslin('c',5*(1+s)/(.1*s.^4+s.^3+15*s.^2+3*s+1)) clf();black(sl,0.01,10); | ![]() | ![]() |
//Black diagram with Nichols chart as a grid s=poly(0,'s'); Plant=syslin('c',16000/((s+1)*(s+10)*(s+100))); //two degree of freedom PID tau=0.2;xsi=1.2; PID=syslin('c',(1/(2*xsi*tau*s))*(1+2*xsi*tau*s+tau.^2*s.^2)); clf(); black([Plant;Plant*PID ],0.01,100,["Plant";"Plant and PID corrector"]); //move the caption in the lower right corner ax=gca();Leg=ax.children(1); Leg.legend_location="in_lower_right"; nicholschart(colors=color('light gray')*[1 1]) | ![]() | ![]() |
Version | Description |
6.0 | handling zpk representation |