Matlab: Some common function for Machatronic Engineer
1. Step - Step response plot of dynamic system
This MATLAB function plots the step response of an arbitrary dynamic system
model sys.
step(sys)
step(sys,Tfinal)
step(sys,t)
step(sys1,sys2,...,sysN)
step(sys1,sys2,...,sysN,Tfinal)
step(sys1,sys2,...,sysN,t)
y = step(sys,t)
[y,t] = step(sys)
[y,t] = step(sys,Tfinal)
[y,t,x] = step(sys)
[y,t,x,ysd] = step(sys)
[y,...] = step(sys,...,options)
2. Hold - Retain current plot when adding new plots
This MATLAB function retains plots in the current axes so that new plots added
to the axes do not delete existing plots.
hold on
hold off
hold all
hold
hold(ax,'on')
hold(ax,'off')
hold(ax)
3. rlocus
Here is an example of how the function rlocus works:
Consider a randomly generated stable Transfer Function Model:
of the form G(s)=num(s)/den(s):
num =
0 -0.1022 0.0316 0.1934 -0.1795 0.1620
den =
1.0000 6.2190 50.6538 222.7866 359.5180 162.7478
Call rlocus using the following command (see also, help rlocus):
rlocus(tf(num,den));
This MATLAB function plots the step response of an arbitrary dynamic system
model sys.
step(sys)
step(sys,Tfinal)
step(sys,t)
step(sys1,sys2,...,sysN)
step(sys1,sys2,...,sysN,Tfinal)
step(sys1,sys2,...,sysN,t)
y = step(sys,t)
[y,t] = step(sys)
[y,t] = step(sys,Tfinal)
[y,t,x] = step(sys)
[y,t,x,ysd] = step(sys)
[y,...] = step(sys,...,options)
2. Hold - Retain current plot when adding new plots
This MATLAB function retains plots in the current axes so that new plots added
to the axes do not delete existing plots.
hold on
hold off
hold all
hold
hold(ax,'on')
hold(ax,'off')
hold(ax)
3. rlocus
Here is an example of how the function rlocus works:
Consider a randomly generated stable Transfer Function Model:
of the form G(s)=num(s)/den(s):
num =
0 -0.1022 0.0316 0.1934 -0.1795 0.1620
den =
1.0000 6.2190 50.6538 222.7866 359.5180 162.7478
Call rlocus using the following command (see also, help rlocus):
rlocus(tf(num,den));
sgrid - Generate s-plane grid of constant damping factors and natural frequencies
This MATLAB function generates, for pole-zero and root locus plots, a grid of
constant damping factors from zero to one in steps of 0.1 and natural
frequencies from zero to 10 rad/sec in steps of one rad/sec, and plots the grid
over the current axis.
sgrid
sgrid(z,wn)
rlocfind Find root locus gains for a given set of roots.
[K,POLES] = rlocfind(SYS) is used for interactive gain
selection from the root locus plot of the SISO system SYS
generated by RLOCUS. rlocfind puts up a crosshair cursor
in the graphics window which is used to select a pole location
on an existing root locus. The root locus gain associated
with this point is returned in K and all the system poles for
this gain are returned in POLES.
[K,POLES] = rlocfind(SYS,P) takes a vector P of desired root
locations and computes a root locus gain for each of these
locations (i.e., a gain for which one of the closed-loop roots
is near the desired location). The j-th entry of the vector K
gives the computed gain for the location P(j), and the j-th
column of the matrix POLES lists the resulting closed-loop poles.
